2007 Oregon Mechanical Specialty Code
First Printing
ISBN-13: 978-1-58001-518-9
ISBN-10: 1-58001-518-2
Publication Date: January 2007
COPYRIGHT© 2006
by
INTERNATIONAL CODE COUNCIL, INC.
ALL RIGHTS RESERVED. This 2007 Oregon Mechanical Specialty Code contains substantial copyrighted material from the
2006 International Mechanical Code, Second Printing, and the 2006 International Fuel Gas Code, Second Printing, which are
copyrighted works owned by the International Code Council, Inc. Without advance written permission from the copyright owner,
no part of this book may be reproduced, distributed or transmitted in any form or by any means, including, without limitation, elec-
tronic, optical or mechanical means (by way of example and not limitation, photocopying, or recording by or in an information stor-
age retrieval system). For information on permission to copy material exceeding fair use, please contact: Publications, 4051 West
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Trademarks: "International Code Council," the "International Code Council" logo and the "International Mechanical Code" are
trademarks of the International Code Council, Inc.
PRINTED IN THE U.S.A.
PREFACE
Internationally, code officials recognize the need for a modem, up-to-date mechanical code addressing the design and installa-
tion of mechanical systems emphasizing performance. The International Mechanical Code®, in this 2006 edition, is designed to
meet these needs through model code regulations that safeguard the public health and safety in all communities, large and small.
This comprehensive mechanical code establishes minimum regulations for mechanical systems using prescriptive and perfor-
mance-related provisions. It is founded on broad-based principles that make possible the use of new materials and new mechanical
system designs. This 2006 edition is fully compatible with all the International Codes® (I-Codes®) published by the International
Code Council (ICC)®, including the International Building Code®, International Code Council Electrical Code Administrative
Provisions, International Energy Conservation Code®, International Existing Building Code®, International Fire Code®, Interna-
tional Fuel Gas Code®, ICC Performance Code®, International Plumbing Code®, International Private Sewage Disposal Code®,
International Property Maintenance Code®, International Residential Code®, International Wildland-Urban Interface Corfe'^^and
International Zoning Code®.
The International Mechanical Code provisions provide many benefits, among which is the model code development process that
offers an international forum for mechanical professionals to discuss performance and prescriptive code requirements. This forum
provides an excellent arena to debate proposed revisions. This model code also encourages international consistency in the applica-
tion of provisions.
The first edition of the International Mechanical Code (1996) was the culmination of an effort initiated in 1995 by a develop-
ment committee appointed by the International Code Council (ICC) and consisting of representatives of the three statutory mem-
bers of the ICC at that time, including: Building Officials and Code Administrators International, Inc. (BOCA), International
Conference of Building Officials (ICBO) and Southern Building Code Congress International (SBCCI). The intent was to draft a
comprehensive set of regulations for mechanical systems consistent with and inclusive of the scope of the existing model codes.
Technical content of the latest model codes promulgated by BOCA, ICBO and SBCCI was utilized as the basis for the development.
This 2006 edition presents the code as originally issued, with changes reflected in subsequent editions through 2003, and with
changes approved through the ICC Code Development Process through 2005. A new edition such as this is promulgated every three
years.
This code is founded on principles intended to establish provisions consistent with the scope of a mechanical code that ade-
quately protects public health, safety and welfare; provisions that do not unnecessarily increase construction costs; provisions that
do not restrict the use of new materials, products or methods of construction; and provisions that do not give preferential treatment to
particular types or classes of materials, products or methods of construction.
Adoption
The International Mechanical Code is available for adoption and use by jurisdictions internationally. Its use within a govern-
mental jurisdiction is intended to be accomplished through adoption by reference in accordance with proceedings establishing the
jurisdiction's laws. At the time of adoption, jurisdictions should insert the appropriate information in provisions requiring specific
local information, such as the name of the adopting jurisdiction. These locations are shown in bracketed words in small capital let-
ters in the code and in the sample ordinance. The sample adoption ordinance on page v addresses several key elements of a code
adoption ordinance, including the information required for insertion into the code text.
The International Mechanical Code is kept up to date through the review of proposed changes submitted by code enforcing offi-
cials, industry representatives, design professionals and other interested parties. Proposed changes are carefully considered through
an open code development process in which all interested and affected parties may participate.
The contents of this work are subject to change both through the Code Development Cycles and the governmental body that
enacts the code into law. For more information regarding the code development process, contact the Code and Standard Develop-
ment Department of the International Code Council.
While the development procedure oiihe. International Mechanical Code assures the highest degree of care, ICC, its members
and those participating in the development of this code do not accept any liability resulting from compliance or noncompliance with
the provisions because ICC and its founding members do not have the power or authority to police or enforce compliance with the
contents of this code. Only the governmental body that enacts the code into law has such authority.
2007 OREGON MECHANiCAL SPECIALTY CODE
Letter Designations in Front of Section Numbers
In each code development cycle, proposed changes to this code are considered at the Code Development Hearings by the ICC
Plumbing Code Development Committee, whose action constitutes a recommendation to the voting membership for final action on
the proposed change. Proposed changes to a code section that has a number beginning with a letter in brackets aie considered by a
different code development committee. For example, proposed changes to code sections that have the letter [B] in front (e.g. [B]
601.2), are considered by the International Building Code Development Committee at the Code Development Hearing.
The content of sections in this code that begin with a letter designation are maintained by another code development commit-
tee in accordance with the following:
[B]= International Building Code Development Committee;
[EC]= International Energy Conservation Code Development Committee;
[FG]= International Fuel Gas Code Development Committee; and
[F]= International Fire Code Development Committee.
Marginal Markings
Solid vertical lines in the margins within the body of the code indicate a technical change from the requirements of the 2003
edition. Deletion indicators (^) are provided in the margin where a paragraph or item has been deleted. > indicates IMC and
IFGC model code language deleted by Oregon. Appendix C is IFGC model code language with some modification by Oregon.
JIThis symbol indicates a State of Oregon amendment has been made to the International Code. Minor changes, such as section
renumbering and removal of references to International Codes are not indicated with a double rule in the margin.
2007 OREGON MECHANICAL SPECIALTY CODE
TABLE OF CONTENTS
CHAPTER 1 ADMINISTRATION 1
Section
101 General 1
102 Applicability 1
103 Department of Mechanical Inspection 2
104 Duties and Powers of the Code Official 3
105 Approval 3
106 Permits 4
107 Inspections and Testing 5
108 Violations 7
109 Means of Appeal 9
CHAPTER 2 DEFINITIONS ...,,.... 11
Section
201 General 11
202 General Definitions 11
CHAPTER 3 GENERAL REGULATIONS 21
Section
301 General 21
302 Protection of Structure 22
303 Equipment and Appliance Location 23
304 Installation 23
305 Piping Support 26
306 Access and Service Space 26
307 Condensate Disposal 27
308 Clearance Reduction 28
CHAPTER 4 VENTILATION .................. 31
Section
401 General 31
402 Natural Ventilation 31
403 Mechanical Ventilation 31
404 Enclosed Parking Garages 34
405 Systems Control 34
406 Ventilation of Uninhabited Spaces 34
CHAPTER 5 EXHAUST SYSTEMS 35
Section
501 General 35
502 Required Systems 35
503 Motors and Fans 41
504 Clothes Dryer Exhaust 42
505 Domestic Kitchen Exhaust Equipment 42
506 Commercial Kitchen Hood Ventilation
System Ducts And Exhaust Equipment 43
507 Commercial Kitchen Hoods 46
508 Commercial Kitchen Makeup Air 48
509 Fire Suppression Systems 49
510 Hazardous Exhaust Systems 49
511 Dust, Stock and Refuse Conveying Systems .... 51
512 Subslab Soil Exhaust Systems 52
513 Smoke Control Systems 52
5 14 Energy Recovery Ventilation Systems 56
CHAPTER 6 DUCT SYSTEMS ...........,,..,, 57
Section
601 General 57
602 Plenums 57
603 Duct Construction and Installation 58
604 Insulation 60
605 Air Filters 61
606 Smoke Detection Systems Control 61
607 Ducts and Transfer Openings 62
CHAPTER 7 COMBUSTION AIR .............. 67
Section
701 General 67
702 Indoor Air 67
703 Outdoor Air 68
704 Combined Use of Indoor and
Outdoor Air (Condition 1) 68
705 Combined Use of Indoor and
Outdoor Air (Condition 2) 68
706 Forced Combustion Air Supply 68
707 Direct Connection 69
708 Combustion Air Ducts 69
709 Opening Obstructions 69
710 Opening Location and Protection 69
CHAPTER 8 CHIMNEYS AND VENTS ......... 71
Section
801 General 71
802 Vents 72
803 Connectors 73
804 Direct-vent, Integral Vent, Mechanical
Draft Systems 74
2007 OREGON MECHANICAL SPECIALTY CODE
TABLE OF CONTENTS
805 Factory-built Chimneys 75
806 Metal Chimneys 76
CHAPTER 9 SPECIFIC APPLIANCES,
FIREPLACES AND SOLID FUEL=
BURNING EQUIPMENT ..........11
Section
901 General 77
902 Masonry Fireplaces 77
903 Factory-built Fireplaces 77
904 Pellet Fuel-burning Appliances 77
905 Fireplace Stoves and Room Heaters 77
906 Factory-built Barbecue Appliances 77
907 Incinerators and Crematories 77
908 Cooling Towers, Evaporative
Condensers and Fluid Coolers 77
909 Vented Wall Furnaces 78
910 Floor Furnaces 78
91 1 Duct Furnaces 78
912 Infrared Radiant Heaters 78
913 Clothes Dryers 78
914 Sauna Heaters 79
915 Engine and Gas Turbine-powered
Equipment and Appliances 79
916 Pool and Spa Heaters 79
917 Cooking Appliances 79
918 Forced-air, Warm-air Furnaces 79
919 Conversion Burners 80
920 Unit Heaters 80
921 Vented Room Heaters 80
922 Kerosene and Oil-fired Stoves 80
923 Small Ceramic Kilns 81
924 Stationary Fuel Cell Power Plants 81
925 Masonry Heaters 81
926 Gaseous Hydrogen Systems 81
927 Wood Stoves 81
CHAPTER 10 BOILERS, WATER HEATERS
AND PRESSURE VESSELS. , . . , o o , 83
Section
1001 General 83
1002 Water Heaters 83
1003 Pressure Vessels 83
1004 Definitions 83
1005 Permits Required 83
1006 Detailed Requirements 84
1007 Expansion Tanks 84
1008 Safety or Relief Valve Discharge 84
1009 Gas-pressure Regulators 84
1010 Clearance for Access 84
101 1 Boiler Room Enclosures 84
1012 Floors 84
1013 Chimneys or Vents 84
1014 Drainage 84
1015 Fuel Supply Piping 84
1016 Air for Combustion and Ventilation 84
1017 Steam and Waterpiping 84
CHAPTER 11 REFRIGERATIONo o .. ..... o .. o = . o 85
Section
1 101 General 85
1 102 System Requirements 85
1 103 Refrigeration System Classification 86
1104 System Application Requirements 90
1 105 Machinery Room, General Requirements 91
1106 Machinery Room, Special Requirements 92
1 107 Refrigerant Piping 93
1 108 Field Test 94
CHAPTER 12 HYDRONIC PIPING ........... ...95
Section
1201 General 95
1202 Material 95
1203 Joints and Connections 96
1204 Pipe Insulation 97
1205 Valves 97
1206 Piping Installation 97
1207 Transfer Fluid 98
1208 Tests 98
1209 Embedded Piping 98
CHAPTER 13 FUEL OIL PIPING
AND STORAGE ... ............... 99
Section
1301 General 99
1302 Material 99
1303 Joints and Connections 99
1304 Piping Support 100
1305 Fuel Oil System Installation 100
1306 Oil Gauging 101
1307 Fuel Oil Valves 101
VD
2007 OREGON MECHANICAL SPECIALTY CODE
TABLE OF CONTENTS
1308 Testing 101
CHAPTER 14 SOLAR SYSTEMS. .............. 103
Section
1401 General 103
1402 Installation 103
1403 Heat Transfer Fluids 103
1404 Materials 104
CHAPTER IS REFERENCED STANDARDS ..... 105
APPENDIX A COMBUSTION AIR OPENINGS AND
CHIMNEY CONNECTOR
PASSTHROUGHS .............. Ill
APPENDIX B RECOMMENDED PERMIT
FEE SCHEDULE ................ 115
APPENDIX C FUEL GAS .................... 117.1
Appendix
C-A Sizing and Capacities of Gas Piping 117.117
C-B Sizing of Venting Systems Serving Appliances
Equipped with Draft Hoods, Category I
Appliances, and Appliances Listed for
Use with Type B Vents 117.127
C-C Exit Terminals of Mechanical Draft and
Direct-vent Venting Systems 117.137
C-D Recommended Procedure for Safety
Inspection of an Existing Appliance
Installation 117.139
FOR CHAPTERS 1--14 .................. 118
X FOR APPENDIX C. .................... 123
2007 OREGON MECHANICAL SPECIALTY CODE
2007 OREGON MECHANICAL SPECIALTY CODE
CHAPTER 1
ADMINISTRATION
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SECTION 101
GENERAL
101.1 Title. These regulations shall be known as the Oregon
Mechanical Specialty Code, hereinafter referred to as "this
code."
1®1.2 Scope. This code shall regulate the design, installation,
alteration and inspection of mechanical systems that are per-
manently installed, and those systems utilized to provide con-
trol of environmental conditions and related processes within
buildings. This code shall also regulate those mechanical sys-
tems, system components, equipment and appliances specifi-
cally addressed herein. Mechanical equipment or systems not
specifically addressed in this code shall be approved by the
code official in accordance with Section 105.2. The installation
of fuel gas distribution piping and equipment, fuel gas-fired
appliances and fuel gas-fired appliance venting systems are
found in Appendix C.
Exception: Structures regulated under the Oregon Residen-
tial Specialty Code.
ORS 455.020(1) is not part of this code but is reproduced here for
the reader's convenience:
455.020 Purpose; scope of application. (1) This chapter is en-
acted to enable the Director of the Department of Consumer and
Business Services to promulgate a state building code to govern the
construcrion, reconstruction, alteration and repair of buildings and
other structures and the installation of mechanical devices and
equipment therein, and to require the correction of unsafe condi-
tions caused by earthquakes in exisdng buildings. The state build-
ing code shall establish uniform performance standards providing
reasonable safeguards for health, safety, welfare, comfort and secu-
rity of the residents of this state who are occupants and users of
buildings, and will provide for the use of modem methods, devices,
materials, techniques and practicable maximum energy conserva-
tion.
101.2.1 Appendices. Provisions in the appendices shall not
I I apply unless specifically adopted. The State of Oregon does
1 I not adopt Appendices A and B. Appendix C is adopted.
101.3 Intent. The purpose of this code is to provide minimum
standards to safeguard life or limb, health, property and public
welfare by regulating and controlling the design, construction,
I I installation and location of mechanical systems.
101.4 Severability. If a section, subsection, sentence, clause or
I I phrase of this code is, for any reason, held to be invahd, such
decision shall not affect the validity of the remaining portions
of this code.
SECTION 102
APPLICABILITY
102.1 General. The provisions of this code shall apply to all
matters affecting or relating to structures and premises, as set
forth in Section 101 . Where, in a specific case, different sections
of this code specify different materials, methods of construction
or other requirements, the most restrictive shall govern.
Note: Boilers and pressure vessels are also regulated by the State of
Oregon Boiler and Pressure Law (ORS 480.5 10 to 480.670).
102.2 Existing installations. Except as otherwise provided for
in this chapter, a provision in this code shall not require the
removal, alteration or abandonment of, nor prevent the contin-
ued utilization and maintenance of an existing mechanical sys-
tem lawfully in existence at the time of the adoption of this
code.
102.3 Maintenance. Not adopted by the State of Oregon.
102.4 Additions, alterations or repairs. Additions, alter-
ations, renovations or repairs to a mechanical system shall con-
form to that required for a new mechanical system without
requiring the existing mechanical system to comply with all of
the requirements of this code. Additions, alterations or repairs
shall not cause an existing mechanical system to become
unsafe, hazardous or overloaded.
Minor additions, alterations, renovations and repairs to
existing mechanical systems shall meet the provisions for new
construction, unless such work is done in the same manner and
arrangement as was in the existing system, is not hazardous and
is approved.
102.5 Change In occupancy. No change shall be made in the
occupancy of any structure which will subject the structure to
any special provision of this code applicable to the new occu-
pancy without approval. The code official shall certify that
such structure meets the intent of the provisions of the Oregon
Structural Specialty Code.
102.6 Historic buildings. The provisions of this code relating to
the construction, alteration, repair, enlargement, restoration,
relocation or moving of buildings or structures shall not be man-
datory for existing buildings or structures identified and classi-
fied by the state or local jurisdiction as historic buildings when
such buildings or structures are judged by the code official to be
safe and in the public interest of health, safety and welfare
regarding any proposed construction, alteration, repair, enlarge-
ment, restoration, relocation or moving of buildings.
102.7 Moved buildings. Except as determined by Section
102.2, mechanical systems that are a part of buildings or struc-
II
I I
2007 OREGON MECHANICAL SPECIALTY CODE
tures moved into or within the jurisdiction shall comply with
the provisions of this code for new installations. See ORS
455.410 for moved buildings.
>
>
ORS 455.410 is not a part of this code but is reproduced here for the
reader's convenience:
455.410 Relocated buildings, substantial complknce required;
permits.
( 1 ) Existing buildings or structures which are removed from their
foundation and relocated to another site within this state shall be
in substantial compliance as defined in subsections (2) and (3) of
this section.
(2) "Substantial compliance" means compliance with local con-
struction codes in effect as of the original permit date of the build-
ing or structure, or where there was no permitting required at the
time of original construction, with basic health and safety stan-
dards, as described in the closest dated Uniform Housing Code,
as published by the International Conference of Building Offi-
cials as of the date of construction. Only the insulation, overhead
and underneath the structure, shall be upgraded to the current
insulation requirements of the state building code, or to the maxi-
mum extent possible subject to the design of the structure. Noth-
ing in this statute shall be construed to mean that all heating,
plumbing and electrical systems shall be replaced with systems
meeting current standards for new construction, except that any
life-threatening deficiencies in those systems shall be repaired,
notwithstanding that the cost of rehabilitation may exceed 50 per-
cent of the value of the structure before rehabilitation.
(3) All foundation and basement construction on the structure and
any remodeling at the new location shall be constructed subject to
all applicable local current building and safety codes, or where
none exist, with the applicable standards as described in the Uni-
form Housing Code described in subsection (2) of this section.
(4) All moved houses shall be provided with either battery-oper-
ated or hard-wired smoke detection devices located in accor-
dance with the provisions of the state building code.
(5) Nothing in this section is intended to permit any person to move
a structure unless the person first consults with the appropriate
building inspection authority and obtains all required permits.
102.8 Referenced codes and standards.
IO2.80I Statutory references. This code is adopted pursuant
to Oregon Revised Statutes. Where in any specific case this
code and the statutes specify different requirements, the statute
shall govern. Statutes related to this code are ORS 455.010
through 455.897 and ORS 447.210 through 447.310.
102.8.2 Referenced standards. The standards referenced
herein shall be those that are listed in Chapter 1 5 and such stan-
dards shaU be considered as part of the requirements of this
code to the prescribed extent of each such reference. Where
differences occur between provisions of this code and the ref-
erenced standards, the provisions of this code shall apply.
Statutes referenced may be obtained from the Building Codes Divi-
sion, P.O. Box 14470, Salem OR 97309-0404.
SECTION 103
DEPARTMENT OF MECHANICAL INSPECTION
103ol Liability. See ORS 30.265 for regulations relating to lia-
bihty.
ORS 30.265 is not a part of this code but is reproduced here for the
reader's convenience.
ORS 30.265 Scope of liability of public body, officers, employ-
ees and agents; liability in nuclear incident.
(1) Subject to the limitations of ORS 30.260 to 30.300, every pub-
lic body is subject to action or suit for its torts and those of its offi-
cers, employees and agents acting within the scope of their
employment or duties, whether arising out of a governmental or
proprietary function or while operating a motor vehicle in a
ridesharing arrangement authorized under ORS 276.598. The
sole cause of action for any tort of officers, employees or agents
of a public body acting within the scope of their employment or
duties and eligible for representation and indemnification under
ORS 30.285 or 30.287 shall be an action against the public body
only. The remedy provided by ORS 30.260 to 30.300 is exclusive
of any other action or suit against any such officer, employee or
agent of a pubhc body whose act or omission within the scope of
the officer's, employee's or agent's employment or duties gives
rise to the action or suit. No other form of civil action or suit shall
be permitted. If an action or suit is filed against an officer,
employee or agent of a public body, on appropriate motion the
pubhc body shall be substituted as the only defendant.
(2) Every public body is immune from hability for any claim for
injury to or death of any person or injury to property resulting
from an act or omission of an officer, employee or agent of a pub-
lic body when such officer, employee or agent is immune from
liability.
(3) Every public body and its officers, employees and agents act-
ing wi thin the scope of their employment or duties, or while oper-
ating a motor vehicle in a ridesharing arrangement authorized
under ORS 276.598, are immune from liability for:
(a) Any claim for injury to or death of any person covered by
any workers' compensation law.
(b) Any claim in connection with the assessment and collec-
tion of taxes.
(c) Any claim based upon the performance of or the failure to
exercise or perform a discretionary function or duty, whether
or not the discretion is abused.
(d) Any claim that is limited or barred by the provisions of any
other statute, including but not limited to any statute of ulti-
mate repose.
(e) Any claim arising out of riot, civil commotion or mob
action or out of any act or omission in connection witli the pre-
vention of any of the foregoing.
(f) Any claim arising out of an act done or omitted under
ap]3arent authority of a law, resolution, rule or regulation that
is unconstitutional, invalid or inapplicable except to the extent
that they would have been liable had the law, resolution, rule
or regulation been constitutional, valid and applicable, unless
such act was done or omitted in bad faith or with malice.
(4) Subsection (1) of this section apphes to any action of any offi-
cer, employee or agent of the state relating to a nuclear incident,
whether or not the officer, employee or agent is acting within the
scope of employment, and provided the nuclear incident is cov-
ered by an insurance or indemnity agreement under 42 U.S.C.
2210.
(5) Subsection (3)(c) of this section does not apply to any discre-
tionary act that is found to be the cause or partial cause of a
nuclear incident covered by an insurance or indemnity agreement
under the provisions of 42 U.S.C. 2210, including but not limited
to road design and route selection. [1967 c.627 §§2,3,10; 1969
c.429 §1; 1975 c.609 §12; 1977 c.823 §2; 1981 c.490 §4; 1985
c.731 §31; 1987 c.705 §7; 1991 c.861 §1; 2005 c.22 §19].
2007 OREGON MECHANICAL SPECIALTY CODE
ADMINISTRATION
DUTIES AMD POWI
1^,
>
I I
by a muEkipality
noted below, this
1(0)4.1 GeMerafl. The code official shall enforce the provisions
of this code and shall act on any question relative to the installa-
tion, alteration or repair of mechanical systems, except as oth-
erwise specifically provided for by statutory requirements.
Note; Section 104.2 is not adopted by the State of Oregon.
The code official shall have
authority as necessary in the interest of public health, safety
and general welfare, to adopt and promulgate rules and regula-
tions; to interpret and implement the provisions of this code; to
secure the intent thereof; and to designate requirements appli-
cable because of local climatic or other conditions. Such rules
shall not have the effect of waiving structural or fire perfor-
mance requirements specifically provided for in this code, or of
violating accepted engineering methods involving public
safety.
The code official shall
receive applications and issue permits for the installation and
alteration of mechanical systems, inspect the premises for
which such permits have been issued and enforce compliance
with the provisions of this code.
The code official shall make all of the
required inspections. All reports of such inspections shall be in
writing and be certified by a responsible officer of such
approved agency or by the responsible individual.
Whenever it is necessary to make an
inspection to enforce the provisions of this code, or whenever
the code official has reasonable cause to believe that there
exists in a building or upon any premises any conditions or vio-
lations of this code which make the building or premises
unsafe, insanitary, dangerous or hazardous, the code official
shall have the authority to enter the building or premises at all
reasonable times to inspect or to perform the duties imposed
upon the code official by this code. If such building or premises
is occupied, the code official shall present credentials to the
occupant and request entry. If such building or premises is
unoccupied, the code official shall first make a reasonable
effort to locate the owner or other person having charge or con-
trol of the building or premises and request entry. If entry is
refused, the code official has recourse to every remedy pro-
vided by law to secure entry.
When the code official has first obtained a proper inspection
warrant or other remedy provided by law to secure entry, an
owner or occupant or person having charge, care or control of
the building or premises shall not fail or neglect, after proper
request is made as herein provided, to promptly permit entry
therein by the code official for the purpose of inspection and
examination pursuant to this code.
orders. The code official shall issue all nec-
essary notices or orders to ensure compliance with this code.
1(0)4.7 Departmeeit records. The code official shall keep offi-
cial records as dictated by OAR 166-150-0020 where a county
has jurisdiction; OAR 166-200-0025 where a city has jurisdic-
tion; and OAR Division 166, Chapter 300 for the cities and
counties where the State of Oregon has jurisdiction. ^
SECTION 105
APPROVAL
Note: ORS 455.060 provides for state rulings on acceptable mate-
rials, design and methods of construction. When a ruling has been
issued, ORS 455.060(4) applies.
ORS 455.060(4) is not part of this code but is reproduced here
for the reader's convenience:
455.060 Rulings on acceptability of material, design or method
of construction; effect of approval.
(4) A building official or inspector shall approve the use of any
material, design or method of construction approved by the direc-
tor pursuant to this section if the requirements of all other local
ordinances are satisfied.
105.1 Modifications. Whenever there are practical difficulties
involved in carrying out the provisions of this code, the code
official shall have the authority to grant modifications for indi-
vidual cases, provided the code official shall first find that spe-
cial individual reason makes the strict letter of this code
impractical and the modification is in compliance with the
intent and purpose of this code and does not lessen health, life
and fire safety requirements. The details of action granting
modifications shall be recorded and entered in the files of the
mechanical inspection department.
105.2 Alternative materials, methods, equipment and
appliances. The provisions of this code are not intended to pre-
vent the installation of any material or to prohibit any method
of construction not specifically prescribed by this code, pro-
vided that any such alternative has been approved. An alterna-
tive material or method of construction shall be approved
where the code official finds that the proposed design is satis-
factory and complies with the intent of the provisions of this
code, and that the material, method or work offered is, for the
purpose intended, at least the equivalent of that prescribed in
this code in quality, strength, effectiveness, fire resistance,
durability and safety.
105.3 Required testing. Whenever there is insufficient evi-
dence of compliance with the provisions of this code, or evi-
dence that a material or method does not conform to the
requirements of this code, or in order to substantiate claims for
alternative materials or methods, the code official shall have the
authority to require tests as evidence of compliance to be made
at no expense to the jurisdiction.
105.3.1 Test methods. Test methods shall be as specified in
this code or by other recognized test standards. In the
absence of recognized and accepted test methods, the code
official shall approve the testing procedures.
105.3.2 Testing agency. All tests shall be performed by an
approved agency.
105.3.3 Test reports. Reports of tests shall be retained by
the code official for the period required for retention of pub-
lic records.
2007 OREGOfM WIECHAMICAL SPECIALTY CODE
ADW1IMBSTRATI10N
WSA Material, equipment and appliance reuseo Materials,
equipment, appliances and devices shall not be reused unless
such elements have been reconditioned, tested and placed in
good and proper working condition and approved.
SECTION 106
PERMITS
I I Note: Unless amended by a municipality, under authority of ORS
I I 455.020, the following shall apply.
106.1 When required. An owner, authorized agent or contrac-
tor who desires to erect, install, enlarge, alter, repair, remove,
convert or replace a mechanical system, the installation of
which is regulated by this code, or to cause such work to be
done, shall first make apphcation to the code official and obtain
I I the required permit for the work [see ORS 455.020(2)].
Exception; Where equipment and appliance replacements
or repairs must be performed in an emergency situation, the
permit application shall be submitted within the next work-
ing business day of the department of mechanical inspec-
tion.
106o2 Permits not required. Permits shall not be required for
the following:
1. Portable heating appliances;
2. Portable ventilation appliances and equipment;
3. Portable cooling units;
4. Steam, hot water or chilled water piping within any heat-
ing or cooling equipment or appliances regulated by this
code;
5 . The replacement of any minor part that does not alter the
approval of equipment or an appliance or make such
equipment or appliance unsafe;
6. Portable evaporative coolers;
7. Self-contained refrigeration systems that contain 10
pounds (4.5 kg) or less of refrigerant, or that are actuated
by motors of 1 horsepower (0.75 kW) or less; and
8. Portable fuel cell appliances that are not connected to a
fixed piping system and are not interconnected to a
power grid.
Exemption from the permit requirements of this code shall
not be deemed to grant authorization for work to be done in vio-
lation of the provisions of this code or other laws or ordinances
of this jurisdiction.
I I Note: Unless amended by a municipality, under authority of ORS
1 I 455.020, the following shall apply.
106.3 Application for permit. Each application for a permit,
with the required fee, shall be filed with the code official on a
form furnished for that purpose and shall contain a general
description of the proposed work and its location. The applica-
tion shall be signed by the owner or an authorized agent. The
permit application shall indicate the proposed occupancy of all
parts of the building and of that portion of the site or lot, if any,
not covered by the building or structure and shall contain such
other information required by the code official.
Exception: For those inspecting jurisdictions that may have
adopted a master permit and/or minor label program under
OAR Chapter 918, Division 100, different requirements
may also apply.
106.3.1 Construction documents. Construction docu-
ments, engineering calculations, diagrams and other data
shall be submitted in two or more sets with each application
for a permit. The code official shall require construction
documents, computations and specifications to be prepared
and designed by a registered design professional when
required by state law. Construction documents shall be ^
drawn to scale and shall be of sufficient clarity to indicate
the location, nature and extent of the work proposed and
show in detail that the work conforms to the provisions of
this code. Construction documents for buildings more than
two stories in height shall indicate where penetrations will
be made for mechanical systems. ^
Exception: The code official shall have the authority to
waive the submission of construction documents, calcu-
lations or other data if the nature of the work applied for
is such that reviewing of construction documents is not
necessary to determine compliance with this code.
106.3.2 Time limitation of application. An application for
a permit for any proposed work shall be deemed to have
been abandoned 180 days after the date of filing, unless such
application has been pursued in good faith or a permit has
been issued; except that the building official is authorized to
grant one or more extensions of time for additional periods
not exceeding 90 days each. The extension shall be
requested in writing and justifiable cause demonstrated.
Note: Unless amended by a municipality, under authority of ORS
455.020, the following shall apply.
106.4 Permit issuance. The application, construction docu-
ments and other data filed by an applicant for a permit shall be
reviewed by the code official. If the code official finds that the
proposed work conforms to the requirements of this code and
all laws and ordinances applicable thereto, and that the fees
specified in Section 106.5 have been paid, a permit shall be
issued to the applicant.
Note: For those inspecting jurisdictions that may have adopted a
master permit and/or minor label program different require-
ments may also apply.
106.4.1 Approved construction documents. When the
code official issues the permit where construction docu-
ments are required, the construction documents shall be
endorsed in writing and stamped "APPROVED." Such
approved construction documents shall not be changed,
modified or altered without authorization from the code
official. Work shall be done in accordance with the
approved construction documents.
The code official shall have the authority to issue a permit
for the construction of part of a mechanical system before
the construction documents for the entire system have been
submitted or approved, provided adequate information and
detailed statements have been filed complying with all perti-
nent requirements of this code. The holder of such permit
shall proceed at his or her own risk without assurance that
the permit for the entire mechanical system will be granted.
2007 OREGON MECHANICAL SPECIALTY CODE
ADMINISTRATION
>
>.4,2 Validity. The issuance of a permit or approval of
construction documents shall not be construed to be a per-
mit for, or an approval of, any violation of any of the provi-
sions of this code or of other ordinances of the jurisdiction.
A permit presuming to give authority to violate or cancel the
provisions of this code shall be invalid.
The issuance of a permit based upon construction docu-
ments and other data shall not prevent the code official from
thereafter requiring the correction of errors in said construc-
tion documents and other data or from preventing building
operations from being carried on thereunder when in viola-
tion of this code or of other ordinances of this jurisdiction.
.4,3 ExpiratioKo Every permit issued by the code offi-
cial under the provisions of this code shall expire by limita-
tion and become null and void if the work authorized by
such permit is not commenced within 180 days from the
date of such permit, or if the work authorized by such permit
is suspended or abandoned at any time after the work is
commenced for a period of 180 days. Before such work
recommences, a new permit shall be first obtained and the
fee, therefore, shall be one-half the amount required for a
new permit for such work, provided no changes have been
made or will be made in the original construction docu-
ments for such work, and provided further that such suspen-
sion or abandonment has not exceeded one year.
i.4.4 Extensions. A permittee holding an unexpired per-
mit shall have the right to apply for an extension of the time
within which the permittee will commence work under that
permit when work is unable to be commenced within the
time required by this section for good and satisfactory rea-
sons. The code official shall extend the time for action by the
permittee for a period not exceeding 180 days if there is rea-
sonable cause. A permit shall not be extended more than
once.
106.4.5 Suspension or revocation of permit. The code
official shall revoke a permit or approval issued under the
provisions of this code in case of any false statement or mis-
representation of fact in the application or on the construc-
tion documents upon which the permit or approval was
based.
5.4.6 Retention of construction documents. One set of
construction documents shall be retained by the code offi-
cial for a period of not less than that dictated by OAR
166-150-0020 where a county has jurisdiction; OAR
166-200-0025 where a city has jurisdiction; and OAR Divi-
sion 166, Chapter 300 for the jurisdictions where the State
of Oregon has jurisdiction. One set of approved construc-
tion documents shall be returned to the applicant, and said
set shall be kept on the site of the building or job at all times
during which the work authorized thereby is in progress.
Note: Unless amended by a municipality, under authority of ORS
455.020 (4), the foUowing shall apply.
106.5 Fees. A permit shall not be issued until the fees pre-
scribed in Section 106.5.2 have been paid, nor shall an amend-
ment to a permit be released until the additional fee, if any, due
to an increase of the mechanical system, has been paid.
106.5.1 Work commencing before permit issuance. Any
person who commences work on a mechanical system
before obtaining the necessary permits shall be subject to
100 percent of the usual permit fee in addition to the
required permit fees.
106.5.2 Fee schedule. The fees for mechanical work shall
be as indicated in the following schedule (see page 7).
Note: Mechanical permit fees are adopted as fees for the Building
Codes Division as required by ORS 455.210(2). Oregon munici-
palities may adopt their own fees according to ORS 455.150 and
455.210(3).
Note: Section 105.3 is not adopted by the State of Oregon.
106.5.3 Fee refunds. The code official shall authorize the
refunding of fees as follows:
1 . The full amount of any fee paid hereunder which was
erroneously paid or collected.
2. Not more than [SPECIFY percentage] percent of the
permit fee paid when no work has been done under a
permit issued in accordance with this code.
3. Not more than [SPECIFY PERCENTAGE] percent of the
plan review fee paid when an application for a permit
for which a plan review fee has been paid is with-
drawn or canceled before any plan review effort has
been expended.
The code official shall not authorize the refunding of any
fee paid, except upon written application filed by the origi-
nal permittee not later than 180 days after the date of fee
payment.
106.5.4 Plan review fees. When a plan or other data is
required to be submitted by Section 106.3.1, a plan review
fee shall be paid at the time of submitting plans and specifi-
cations for review. The plan review fees for mechanical
work shall be equal to 25 percent of the total permit fee as set
forth in Table 1- A.
106.5.4.1 Separate fees for plan review. The plan
review fees specified in this section are separate fees
from the permit fees specified in Section 106.5.2 and are
in addition to the permit fees.
106.5.4.2 Incomplete or changed plans. When plans
are incomplete or changed so as to require additional
plan review, an additional plan review fee shall be
charged at the rate shown in Table 1-A.
SECTION 107
INSPECTIONS AND TESTING
107.1 Required inspections and testing. The code official,
upon notification from the permit holder or the permit holder's
agent, shall make the following inspections and other such
inspections as necessary, and shall either release that portion of
the construction or shall notify the permit holder or the permit
holder's agent of violations that must be corrected. The holder
of the permit shall be responsible for the scheduling of such
inspections.
1 . Underground inspection shall be made after trenches or
ditches are excavated and bedded, piping installed, and
2007 OREGON MECHANSCAL SPECIALTY CODE
TABLE 1-A
lECHAMICAL PERMIT FEES
PERMIT ISSUANCE
1 . For the issuance of each permit.
$13.00
2. For issuing each supplemental permit.
3.90
UNIT FEE SCHEDULE
1 . For the installation or relocation of each forced-air or gravity-type furnace or burner, including ducts and vents attached to :
such appUance, up to and including 100,000 Btu/h (29.3 kW). , ''^^
2. For the installation or relocation of each forced-air or gravity-type furnace or burner, including ducts and vents attached to
such appliance over 100,000 Btu/h (29.3 kW).
9.75
3. For the installation or relocation of each floor furnace, including vent.
7.80
4. For the installation or relocation of each suspended heater, recessed wall heater or floor-mounted unit heater.
7.80
5. For the installation, relocation or replacement of each appliance vent installed and not included in an appliance permit.
3.90
6. For the repair of, alteration of, or addition to each heating appliance, refrigeration unit, cooling unit, absorption unit or each
heating, cooling, absorption, or evaporative cooling system, including installation of controls regulated by this code.
7.80
7. For the installation or relocation of each compressor to and including three horsepower (10.6 kW), or each absorption sys-
tem to and including 100,000 Btu/h (29.3kW).
7.80
8. For the installation or relocation of each compressor over three horsepower (10.6 kW), to and including 15 horsepower
(52.7 kW), or each absorption system over 100,000 Btu/h (29.3 kW) to and including 500,000 Btu/h (146.6 kW).
14.30
9. For the installation or relocation of each compressor over 15 horsepower (52.7 kW) to and including 30 horsepower (105.5
kW), or each absorption system over 500,000 Btu/h (146.6 kW) to and including 1,000,000 Btu/h (293.1 kW).
19.50
10. For the installation or relocation of each compressor over 30 horsepower (105.5 kW) to and including 50 horsepower (176
kW), or for each absorption system over 1,000,000 Btu/h (293.1 kW) to and including 1,750,000 Btu/h (512.9 kW).
29.25
1 1 . For the installation or relocation of each refrigeration compressor over 50 horsepower (176 kW), or each absorption system
over 1,750,000 Btu/h (512.9 kW).
48.75
12. For each air-handling unit to and including 10,000 cubic feet per minute (4720 L/s), including ducts attached thereto.
(Note: This fee shall not apply to an air-handling unit which is a portion of a factory-assembled apphance, cooling unit,
evaporative cooler or absorption unit for which a permit is required elsewhere in this code.)
5.85
13. For each air-handling unit exceeding 10,000 cfm (4720 L/s).
9.75
14. For each evaporative cooler other than portable type.
5.85
15. For each ventilation fan connected to a single duct.
3.90
16. For each ventilation system which is not a portion of any heating or air-conditioning system authorized by a permit.
5.85
17. For the installation of each hood which is served by mechanical exhaust, including the ducts for such hood.
5.85
18. For the installation or relocation of each domestic-type incinerator.
9.75
19. For the installation or relocation of each commercial or industrial-type incinerator.
39.00
20. For each appliance or piece of equipment regulated by this code, but not classed in other appliance categories or for which
no other fee is listed in this code.
5.85
21. Permit fees for fuel-gas piping shall be as follows:
For each gas-piping system of one to four outlets.
For each gas -pi ping system of five or more outlets, per outlet.
2.60
0.65
OTHER INSPECTIONS AND FEES
1. Inspections outside normal business hours (minimum charge 2 hours).
$19.50/hour
2. Reinspection fees assessed under provisions of Section 107.2.3.
19.50 each
3. Inspections for which no fee is specifically indicated (minimum charge V^ hour).
19.50/hour
4. Additional plan review required by changes, additions, or revisions to approved plans (minimum charge '/^ hour).
19.50/hour
2007 OREGOM WIECHAMICAL SPEC8ALTY CODE
ADMINISTRATION
>
before backfill is put in place. When excavated soil con-
tains rocks, broken concrete, frozen chunks and other
rubble that would damage or break the piping or cause
corrosive action, clean backfill shall be on the job site.
2. Rough-in inspection shall be made after the roof, fram-
ing, fireblocking and bracing are in place and all ducting
and other components to be concealed are complete, and
prior to the installation of wall or ceiling membranes.
3. Final inspection shall be made upon completion of the
mechanical system.
Exceptions Ground-source heat pump loop systems tested
in accordance with Section 1208. 1 . 1 shall be permitted to be
backfilled prior to inspection.
The requirements of this section shall not be considered to
prohibit the operation of any heating equipment or appliances
installed to replace existing heating equipment or appliances
serving an occupied portion of a structure provided that a
request for inspection of such heating equipment or appliances
has been filed with the department not more than 48 hours after
such replacement work is completed, and before any portion of
such equipment or appliances is concealed by any permanent
portion of the structure.
107.2 Testing. Mechanical systems shall be tested as required
in this code and in accordance with Sections 107.2.1 through
107.2.3. Tests shall be made by the permit holder and observed
by the code official.
107o2ol New, altered, extended or repaired systems. New
mechanical systems and parts of existing systems, which
have been altered, extended, renovated or repaired, shall be
tested as prescribed herein to disclose leaks and defects.
107.2.2 Apparatus, material and labor for tests. Appara-
tus, material and labor required for testing a mechanical sys-
tem or part thereof shall be furnished by the permit holder.
107.2.3 Reinspection and testing. Where any work or
installation does not pass an initial test or inspection, the
necessary corrections shall be made so as to achieve compli-
ance with this code. The work or installation shall then be
resubmitted to the code official for inspection and testing.
107.3 Contractor responsibilities. It shall be the responsibil-
ity of every contractor who enters into contracts for the installa-
tion or repair of mechanical systems for which a permit is
required to comply with adopted state and local rules and regu-
lations concerning licensing and permits.
After the prescribed tests and inspections
indicate that the work complies in all respects with this code, a
notice of approval shall be issued by the code official.
107.S Temporary connection. The code official shall have the
authority to authorize the temporary connection of a mechani-
cal system to the sources of energy for the purpose of testing
mechanical systems or for use under a temporary certificate of
occupancy.
SECTION 108
VIOLATIONS
108.1 Prohibited acts are described in ORS 455.450.
ORS 455.450 is not part of this code but is reproduced here for the
reader's convenience:
455.450 Prohibited acts. A person shall not:
(1) Violate or procure, aid or abet in the violation of any final
order concerning the application of a provision of the state build-
ing code in a particular case made by the Director of the Depart-
ment of Consumer and Business Services, an advisory board, a
state administrative officer or any local appeals board, building
official or inspector.
(2) Engage in or procure, aid or abet any other person to engage in
any conduct or activity for which a permit, certificate, label or
other formal authorization is required by any specialty code or
other regulation promulgated pursuant to this chapter without
first having obtained such permit, certificate, label or other for-
mal authorization.
108.2 Notice of violation. The code official shall serve a notice
of violation or order to the person responsible for the erection,
installation, alteration, extension or repair of mechanical work
in violation of the provisions of this code, or in violation of a
detail statement or the approved construction documents there-
under, or in violation of a permit or certificate issued under the
provisions of this code. Such order shall direct the discontinu-
ance of the illegal action or condition and the abatement of the
violation.
108.3 Violation penalties.
108.3.1 General. Persons who violate a provision of this
code or fail to comply with any of the requirements thereof
or who erects, installs, alters or repairs mechanical work in
violation of the approved construction documents or direc-
tive of the code official, or of a permit or certificate issued
under the provisions of this code may be subject to penalties
as prescribed by law.
108.3.2 Penalties. Penalties for violations are prescribed in
ORS 455.895 or as adopted by the municipality having
authority. Local authority to levy penalties is limited to vio-
lations of code application only unless authorized as an
agent under ORS 455.156.
108.4 Stop work orders. Upon notice from the code official
that mechanical work is being done contrary to the provisions
of this code or in a dangerous or unsafe manner, such work
shall immediately cease. Such notice shall be in writing and
shall be given to the owner of the property, or to the owner's
agent, or to the person doing the work. The notice shall state the
conditions under which work is authorized to resume. Where
an emergency exists, the code official shall not be required to
give a written notice prior to stopping the work. Any person
who shall continue any work on the system after having been
served with a stop work order, except such work as that person
is directed to perform to remove a violation or unsafe condi-
tion, may be liable for a fine.
I I
<
II
<
II
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2007 OREGON MECHANICAL SPECIALTY CODE
ORS 455.895 and 455.156 are not part of this code but are repro-
duced here for the reader's convenience:
455.895 Civil penalties.
(1)
(a) The State Plumbing Board may impose a civil penalty against
a person as provided under ORS 447.992 and 693.992. Amounts
recovered under this paragraph are subject to ORS 693.165.
(b) The Electrical and Elevator Board may impose a civil pen-
alty against a person as provided under ORS 479.995. Amounts
recovered under this paragraph are subject to ORS 479.850.
(c) The Board of Boiler Rules may impose a civil penalty against
a person as provided under ORS 480.670. Amounts recovered
under this paragraph shall be deposited to the General Fund.
(2) The Director of the Department of Consumer and Business Ser-
vices, in consultation with the appropriate board, if any, may
impose a civil penalty against any person who violates any provi-
sion of ORS 446.003 to 446.200, 446.225 to 446.285, 446.395 to
446.420, 446.566 to 446.646, 446.666 to 446.746, 479.510 to
479.945, 479.950 and 480.510 to 480.670 and this chapter and
ORS chapters 447, 460 and 693, or any rule adopted or order issued
for the administration and enforcement of those provisions. Except
as provided in subsections (3) and (8) of this section or ORS
446.995, a civil penalty imposed under this section must be in an
amount determined by the appropriate board or the director of not
more than $5,000 for each offense or, in the case of a continuing
offense, not more than $1,000 for each day of the offense.
(3) Each violation of ORS 446.003 to 446.200 or 446.225 to
446.285, or any rule or order issued thereunder, constitutes a sep-
arate violation with respect to each manufactured structure or
with respect to each failure or refusal to allow or perform an act
required thereby, except that the maximum civil penalty may not
exceed $ 1 million for any related series of violations occurring
within one year from the date of the first violation.
(4) The maximum penalty estabUshed by this section for a viola-
tion may be imposed only upon a finding that the person has
engaged in a pattern of violations. The Department of Consumer
and Business Services, by rule, shall define what constitutes a
pattern of violations. Except as provided in subsections (1) and
(9) of this section, moneys received from any civil penalty under
this section are appropriated continuously for and shall be used
by the director for enforcement and administration of provisions
and rules described in subsecfion (2) of this section.
(5) Civil penalties under this secdon shall be imposed as provided
in ORS 183.745.
(6) A civil penalty imposed under this section may be remitted or
reduced upon such ternis and conditions as the director or the appro-
priate board considers proper and consistent with the public health
and safety. In any judicial review of a civil penalty imposed under
this section, the court may, in its discretion, reduce the penalty.
(7) Any officer, director, shareholder or agent of a corporation, or
member or agent of a partnership or association, who personally
participates in or is an accessory to any violation by the partner-
ship, association or corporation of a provision or rule described in
subsection (2) of this section is subject to the penalties prescribed
in this section.
(8) hi addition to the civil penalty set forth in subsection (1) or (2) of
this section, any person who violates a provision or rule described in
subsection (2) of this section may be required by the director or the
appropriate board to forfeit and pay to the General Fund of the State
Treasury a civil penalty in an amount determined by the director or
board that shall not exceed five times the amount by which such per-
son profited in any transaction that violates a provision or rule
described in subsection (2) of this section.
455.156 Municipal investigation and enforcement of certain
violations; notice of civil penalty; department to develop pro-
grams; defense for violation of building inspection program.
(1) Notwithstanding any other provision of this chapter, ORS
chapter 693 or ORS 447.010 to 447.156, 447.992, 479.510 to
479.945, 479.990 or 479.995, the Department of Consumer and
Business Services shall carry out the provisions of this secfion.
(2)
(a) A municipality that establishes a building inspection pro-
gram under ORS 455.148 or a plumbing inspection program
under ORS 455.150 covering installations under the plumb-
ing specialty code or Low-Rise Residential Dwelling Code
may act on behalf of the State Plumbing Board to investigate
violations of and enforce ORS 447.040, 693.030 and 693.040
and to issue notices of proposed assessment of civil penalties
for those violations.
(b) A municipality that establishes a building inspection pro-
gram under ORS 455. 148 or an electrical inspection program
under ORS 455.150 covering installations under the electrical
specialty code or Low-Rise Residential Dwelling Code may
act on behalf of the Electrical and Elevator Board to investi-
gate violations of and enforce ORS 479.550 (1) and 479.620
and to issue notices of proposed assessment of civil penalties
for those violations.
(c) A municipality that establishes a building inspection pro-
gram under ORS 455.148 or 455.150 may investigate viola-
tions and enforce any provisions of the program administered
by the municipality.
(3) The department shall establish;
(a) Procedures, forms and standards to carry out the provi-
sions of this section, including but not limited to creating
preprinted notices of proposed assessment of penalties that
can be completed and served by municipal inspectors;
(b) A program to provide that all of the moneys recovered by
the department, less collection expenses, be paid to the
municipality that initiated the charges when a person charged
with a violation as provided in subsection (2) of this section,
other than a violation of a licensing requirement, agrees to the
entry of an assessment of civil penalty or does not request a
hearing, and an order assessing a penalty is entered against the
person;
(c) A uniform citation process to be used in all jurisdictions of
the state for violation of a Ucensing requirement. The process
may include but need not be limited to all program areas
administered by a municipality under ORS 455.148 or
455.150 and may provide a uniform method for checking
license status and issuing citations for violation of a licensing
requirement, and a consistent basis for enforcement of licens-
ing requirements and treatment of violations, including fine
amounts;
(d) A program to provide a division of the moneys recovered
by the department with the municipality that initiated the
charges, when a person charged with a violation as provided
in subsection (2) of this section, other than a violation of a
licensing requirement, requests a hearing and is assessed a
penalty. One-half of the amounts recovered shall be paid to
the municipality. The department shall keep an amount equal
to its costs of processing the proceeding and collection
expenses out of the remaining one-half and remit the balance,
if any, to tiie municipality; and
(e) A program to require municipalities to investigate viola-
tions of the department's permit requirements for plumbing
installations and services under the plumbing specialty code
2007 OREGON MECHANICAL SPECIALTY CODE
ADMINISTRATIOM
and for plumbing and electrical installations and services
under the Low-Rise Residential Dwelling Code, and to:
(A) Initiate notices of proposed assessment of civil penal-
ties as agents of the boards designated in subsection (2) of
this section; and
(B) Pay the agents of the boards out of net civil penalty
recoveries as if the recoveries were under paragraphs (b)
and (d) of this subsection.
(4) The assessment of a civil penalty under this section by a
municipality is subject to the amount limitations set forth in ORS
455.895.
(5)
(a) It shall be a defense for any person charged with a penalty
for violation of a building inspection program permit require-
ment covering plumbing installations under the plumbing
specialty code, electrical permit requirements under ORS
479.550 or plumbing or electrical requirements under the
Low-Rise Residential Dwelling Code that the person was pre-
viously penalized for the same occurrence.
(b) A building inspection program permit requirement is a
requirement contained in a specialty code or municipal ordi-
nance or rule requiring a permit before the particular installa-
tions covered by the codes are commenced.
(c) A penalty for the same occurrence includes a combination
of two or more of the following that are based on the same
plumbing or electrical installation:
(A)
(i) An investigative or other fee added to an electrical
permit fee when a permit was obtained after the electri-
cal installation was started;
(ii) A civil penalty pursuant to ORS 479.995 for viola-
tion of ORS 479.550 for failure to obtain an electrical
permit;
(iii) A civil penalty pursuant to ORS 455.895 for failure
to obtain an electrical permit under the Low-Rise Resi-
dential Dwelhng Code; or
(iv) A municipal penalty, other than an investigative fee,
for making an electrical installation under the electrical
specialty code or the Low-Rise Residential Dwelling
Code without a permit; or
(B)
(i) An investigative or other fee added to a plumbing per-
mit fee when a permit was obtained after the plumbing
installation was started;
(ii) A civil penalty pursuant to ORS 447.992 for failure
to obtain a plumbing permit as required under the
plumbing specialty code;
(iii) A civil penalty pursuant to ORS 455.895 for failure
to obtain a plumbing permit under the Low-Rise Resi-
dential Dwelling Code; or
(iv) A municipal penalty, other than an investigative fee,
for making a plumbing installation under the plumbing
specialty code or the Low-Rise Residential Dwelling
Code without a permit.
SECTION 109
MEANS OF APPEAL
109.1 General. In order to hear and decide appeals of orders,
decisions or determinations made by the building official rela-
tive to the application and interpretation of this code, the local
jurisdiction shall establish an appeals procedure.
109.2 Limitations on authority. An application for appeal
shall be based on a claim that the true intent of this code or the
rules legally adopted thereunder have been incorrectly inter-
preted, the provisions of this code do not fully apply or an
equally good or better form of construction is proposed. An
appeals board, when appointed, shall have no authority to
waive requirements of this code.
109.3 Appeal of decision of building official. ORS 455.475
provides an alternative appeals process to that set forth by the
local municipality.
<
ORS 455.475 is not part of this code but is reproduced here for the
reader's convenience:
455.475 Appeal of decision of building official. A person aggrieved
by a decision made by a building official under authority established
pursuant to ORS 455. 148, 455. 150 or 455.467 may appeal the deci-
sion. The following apply to an appeal under this section:
(1) An appeal under this section shall be made first to the appropri-
ate specialty code chief inspector of the Department of Consumer
and Business Services. The decision of the department chief
inspector may be appealed to the appropriate advisory board. The
decision of the advisory board may only be appealed to the Director
of the Department of Consumer and Business Services if codes in
addition to the applicable specialty code are at issue.
(2) If the appropriate advisory board determines that a decision by
the department chief inspector is a major code interpretation, then
the inspector shall distribute the decision in writing to all applicable
specialty code public and private inspection authorities in the state.
The decision shall be distributed within 60 days after the board's
determination, and there shall be no charge for the distribution of
the decision. As used in this subsection, a "major code interpreta-
tion" means a code interpretation decision that affects or may affect
more than one job site or more than one inspection jurisdiction.
(3) If an appeal is made under this section, an inspection authority
shall extend the plan review deadline by the number of days it takes
for a final decision to be issued for the appeal.
Note: Forms for filing an appeal under ORS 455.475 are available
online at: www.bcd.oregon.gov.
ORS 455.690 allows appeal of alocal appeals board decision to
the state Building Codes Structures Board. Appeals to the
Building Codes Structures Board are limited to those that are
technical and scientific in nature.
ORS 455.690 is not part of this code but is reproduced here for the
reader's convenience:
455.690 Appeal to advisory boards. Any person aggrieved by the
final decision of a municipal appeals board or a subordinate officer of
the Department of Consumer and Business Services as to the applica-
tion of any provision of a specialty code may, within 30 days after the
date of the decision, appeal to the appropriate advisory board. The
appellant shall submit a fee of $20, payable to the department, with the
request for appeal. The final decision of the involved municipality or
state officer shall be subject to review and final determination by the
appropriate advisory board as to technical and scientific determina-
tions related to the application of the specialty code involved.
2007 OREGON MECHANICAL SPECIALTY CODE
10 2007 OREGON MECHANICAL SPECIALTY CODE
DEFINITIONS
GENERAL
2(D)lol Scope. Unless otherwise expressly stated, the following
words and terms shall, for the purposes of this code, have the
meanings indicated in this chapter.
Words used in the present tense
include the future; words in the masculine gender include the
feminine and neuter; the singular number includes the plural
and the plural, the singular.
2(0)1 o3 Terms deSimed in other codes. Where terms are not
defined in this code and are defined in the Building Code, Elec-
trical Code, Fire Code, or the Plumbing Code, such terms shall
have meanings ascribed to them as in those codes.
Except as defined in this chapter or
elsewhere in this code, the interpretation of words used in this
code shall be in accordance with the meanings defined in the
building code and Webster's Third New International Dictio-
nary of the English Language, Unabridged, copyright 1986.
ICTION 202
ABRASIVE MATERIALS. Moderately abrasive particulate
in high concentrations, and highly abrasive particulate in mod-
erate and high concentrations, such as alumina, bauxite, iron
silicate, sand and slag.
ABSORPTION SYSTEM. A refrigerating system in which
refrigerant is pressurized by pumping a chemical solution of
refrigerant in absorbent, and then separated by the addition of
heat in a generator, condensed (to reject heat), expanded, evap-
orated (to provide refrigeration), and reabsorbed in an absorber
to repeat the cycle; the system may be single or multiple effect,
the latter using multiple stages or internally cascaded use of
heat to improve efficiency.
ACCESS (TO). That which enables a device, appliance or
equipment to be reached by ready access or by a means that first
requires the removal or movement of a panel, door or similar
obstruction [see also "Ready access (to)"].
All air supplied to mechanical equipment and appliances
for combustion, ventilation, cooling, etc. Standard air is air at
standard temperature and pressure, namely, 70°F (21°C) and
29.92 inches of mercury (101.3 kPa).
The treatment of air so as to control
simultaneously the temperature, humidity, cleanness and dis-
tribution of the air to meet the requirements of a conditioned
space.
A system that consists of
heat exchangers, blowers, filters, supply, exhaust and return
ducts, and shall include any apparatus installed in connection
therewith.
AIR DISTRIBUTION SYSTEM. Any system of ducts, ple-
nums and air-handling equipment that circulates air within a
space or spaces and includes systems made up of one or more
air-handling units.
AIR, EXHAUST. Air being removed from any space, appli-
ance or piece of equipment and conveyed directly to the atmo-
sphere by means of openings or ducts.
AIR-HANDLING UNIT. A blower or fan used for the pur-
pose of distributing supply air to a room, space or area.
AIR, MAKEUP. Air that is provided to replace air being
exhausted.
ALTERATION. A change in a mechanical system that
involves an extension, addition or change to the arrangement,
type or purpose of the original installation.
APPLIANCE. A device or apparatus that is manufactured and
designed to utilize energy and for which this code provides spe-
cific requirements.
APPLIANCE, EXISTING. Any apphance regulated by this
code which was legally installed prior to the effective date of
this code, or for which a permit to install has been issued.
APPLIANCE TYPE.
High-heat appliance. Any apphance in which the products
of combustion at the point of entrance to the flue under nor-
mal operating conditions have a temperature greater than
2,000°F (1093°C).
Low-heat appliance (residential appliance). Any apph-
ance in which the products of combustion at the point of
entrance to the flue under normal operating conditions have
a temperature of 1,000°F (538°C) or less.
Medium-heat appliance. Any appliance in which the prod-
ucts of combustion at the point of entrance to the flue under
normal operating conditions have a temperature of more
than 1,000°F (538°C), but not greater than 2,000°F
(1093°C).
APPLIANCE, VENTED. An appliance designed and
installed in such a manner that all of the products of combus-
tion are conveyed directly from the appliance to the outdoor
atmosphere through an approved chimney or vent system.
APPROVED. Acceptable to the code official or other author-
ity having jurisdiction.
APPROVED AGENCY. An established and recognized
agency that is approved by the code official and regularly
engaged in conducting tests or furnishing inspection services.
AUTOMATIC BOILER. Any class of boiler that is equipped
with the controls and limit devices specified in Chapter 10.
BATHROOM. A room containing a bathtub, shower, spa or
similar bathing fixture.
2007 OREGON MECHANICAL SPECIALTY CODE
11
DEFINITIONS
BOILERo A closed heating appliance intended to supply hot
water or steam for space heating, processing or power pur-
poses. Low-pressure boilers operate at pressures less than or
equal to 15 pounds per square inch (psi) (103 kPa) for steam
and 160 psi (1 103 kPa) for water. High-pressure boilers operate
at pressures exceeding those pressures.
BOILER ROOM. A room primarily utilized for the installa-
tion of a boiler.
BRAZED JOINT. A gas-tight joint obtained by the joining of
metal parts with metallic mixtures or alloys which melt at a
temperature above 1 ,000°F (538°C), but lower than the melting
temperature of the parts to be joined.
BRAZING. A metal joining process wherein coalescence is
produced by the use of a nonferrous filler metal having a melt-
ing point above 1 ,000°F (538°C), but lower than that of the base
metal being joined. The filler material is distributed between
the closely fitted surfaces of the joint by capillary attraction.
BTU. Abbreviation for British thermal unit, which is the quan-
tity of heat required to raise the temperature of 1 pound (454 g)
of water IT (0.56°C) (1 Btu = 1055 J).
BUILDING. Any structure occupied or intended for support-
ing or sheltering any occupancy.
BUILDING CODE. The Oregon Structural Specialty Code.
BUILDING OFFICIAL. The officer charged with the admin-
istration and enforcement of this code, or a duly authorized rep-
resentative.
CHIMNEY. A primarily vertical structure containing one or
more flues, for the purpose of carrying gaseous products of
combustion and air from a fuel-burning appliance to the out-
door atmosphere.
Factory-built chimney, A listed and labeled chimney com-
posed of factory-made components, assembled in the field
in accordance with manufacturer's instructions and the con-
ditions of the listing.
Masonry chimney. A field-constructed chimney composed
of sohd masonry units, bricks, stones or concrete.
Metal chimney. A field-constructed chimney of metal.
CHIMNEY CONNECTOR. A pipe that connects a
fuel-burning appliance to a chimney.
CLEARANCE. The minimum distance through air measured
between the heat-producing surface of the mechanical appli-
ance, device or equipment and the surface of the combustible
material or assembly.
CLOSED COMBUSTION SOLIDFUELBURNING
APPLIANCE. A heat-producing appliance that employs a
combustion chamber that has no openings other than the flue
collar, fuel charging door and adjustable openings provided to
control the amount of combustion air that enters the combus-
tion chamber.
CLOTHES DRYER. An appliance used to dry wet laundry by
means of heat. Dryer classifications are as follows:
Type 1. Factory-built package, multiple production. Pri-
marily used in family living environment. Usually the
smallest unit physically and in function output.
Type 2. Factory-built package, multiple production. Used in
business with direct intercourse of the function with the
public. Not designed for use in individual family living
environment.
CODE. These regulations, subsequent amendments thereto, or
any emergency rule or regulation that the administrative
authority having jurisdiction has lawfully adopted.
CODE OFFICIAL. See "Building Official." I I
COMBUSTIBLE ASSEMBLY. Wall, floor, ceiling or other
assembly constructed of one or more component materials that
are not defined as noncombustible.
COMBUSTIBLE LIQUIDS. Any liquids having a flash point
at or above 100°F (38°C), and that are divided into the follow-
ing classifications:
Class II. Liquids having flash points at or above 100°F
(38°C) and below 140°F (60°C).
Class HI A. Liquids having flash points at or above 140°F
(60°C) and below 200°F (93°C).
Class IIIB. Liquids having flash points at or above 200°F
(93°C).
COMBUSTIBLE MATERIAL. Any material not defined as
noncombustible.
COMBUSTION. In the context of this code, refers to the rapid
oxidation of fuel accompanied by the production of heat or heat
and light.
COMBUSTION AIR. Air necessary for complete combus-
tion of a fuel, including theoretical air and excess air.
COMBUSTION CHAMBER. The portion of an appliance
within which combustion occurs.
COMBUSTION PRODUCTS. Constituents resulting from
the combustion of a fuel with the oxygen of the air, including
the inert gases, but excluding excess air.
COMMERCIAL COOKING RECIRCULATING SYS-
TEM. Self-contained system consisting of the exhaust hood,
the cooking equipment, the filters, and the fire suppression sys-
tem. The system is designed to capture cooking vapors and res-
idues generated from commercial cooking equipment. The
system removes contaminants from the exhaust air and
recirculates the air to the space from which it was withdrawn.
COMMERCIAL COOKING APPLIANCES. Appliances
used in a commercial food service establishment for heating or
cooking food and which produce grease vapors, steam, fumes,
smoke or odors that are required to be removed through a local
exhaust ventilation system. Such appliances include deep fat
fryers; upright broilers; griddles; broilers; steam-jacketed ket-
tles; hot-top ranges; under-fired broilers (charbroilers); ovens;
barbecues; rotisseries; and similar appliances. For the purpose
of this definition, a food service establishment shall include
any building or a portion thereof used for the preparation and
serving of food.
COMMERCIAL KITCHEN HOODS.
Backshelf hood. A backshelf hood is also referred to as a
low-proximity hood, or as a sidewall hood where wall
mounted. Its front lower lip is low over the appliance(s) and
12
2007 OREGON MECHANICAL SPECIALTY CODE
DEFINITIONS
is "set back" from the front of the appUance(s). It is always
closed to the rear of the appliances by a panel where
free-standing, or by a panel or wall where wall mounted,
and its height above the cooking surface varies. (This style
of hood can be constructed with partial end panels to
increase its effectiveness in capturing the effluent generated
by the cooking operation).
Double island canopy hood. A double island canopy hood
is placed over back-to-back appliances or appliance lines. It
is open on all sides and overhangs both fronts and the sides
of the appliance(s). It could have a wall panel between the
backs of the appliances. (The fact that exhaust air is drawn
from both sides of the double canopy to meet in the center
causes each side of this hood to emulate a wall canopy hood,
and thus it functions much the same with or without an
actual wall panel between the backs of the appliances).
Eyebrow hood. An eyebrow hood is mounted directly to
the face of an appliance, such as an oven and dishwasher,
above the opening(s) or door(s) from which effluent is emit-
ted, extending past the sides and overhanging the front of
the opening to capture the effluent.
Pass-over hood. A pass-over hood is a free-standing form
of a backshelf hood constructed low enough to pass food
over the top.
Single island canopy hood. A single island canopy hood is
placed over a single appliance or appliance Une. It is open on
all sides and overhangs the front, rear, and sides of the appli-
ance(s). A single island canopy is more susceptible to cross
drafts and requires a greater exhaust air flow than an equiva-
lent sized wall-mounted canopy to capture and contain
effluent generated by the cooking operation (s).
Wall canopy hood. A wall canopy exhaust hood is mounted
against a wall above a single appliance or line of appli-
ance(s), or it could be free-standing with a back panel from
the rear of the appliances to the hood. It overhangs the front
and sides of the appliance(s) on all open sides.
The wall acts as a back panel, forcing the makeup air to be
drawn across the front of the cooking equipment, thus
increasing the effectiveness of the hood to capture and con-
tain effluent generated by the cooking operation(s).
COMPENSATING HOODS. Compensating hoods are those
having integral (built-in) makeup air supply. The makeup air
supply for such hoods is generally supplied from: short-circuit
flow from inside the hood, air curtain flow from the bottom of
the front face, and front face discharge from the outside front
wall of the hood. The compensating makeup airflow can also
be supplied from the rear or side of the hood, or the rear, front,
or sides of the cooking equipment. The makeup airflow can be
one or a combination of methods.
COMPRESSOR. A specific machine, with or without acces-
sories, for compressing a gas.
COMPRESSOR, POSITIVE DISPLACEMENT. A com-
pressor in which increase in pressure is attained by changing
the internal volume of the compression chamber.
COMPRESSOR UNIT. A compressor with its prime mover
and accessories.
CONCEALED LOCATION. A location that cannot be
accessed without damaging permanent parts of the building
structure or finish surface. Spaces above, below or behind
readily removable panels or doors shall not be considered as
concealed.
CONDENSATE. The liquid that condenses from a gas
(including flue gas) caused by a reduction in temperature.
CONDENSER. A heat exchanger designed to liquefy refrig-
erant vapor by removal of heat.
CONDENSING UNIT. A specific refrigerating machine
combination for a given refrigerant, consisting of one or more
power-driven compressors, condensers, liquid receivers (when
required), and the regularly furnished accessories.
CONDITIONED SPACE. An area, room or space being
heated or cooled by any equipment or appliance.
CONFINED SPACES. A space having a volume less than 50
cubic feet per 1 ,000 British thermal units per hour (Btu/h) (4.8
m^/kW) of the aggregate input rating of all appliances installed
in that space.
CONSTRUCTION DOCUMENTS. All of the written,
graphic and pictorial documents prepared or assembled for
describing the design, location and physical characteristics of
the elements of the project necessary for obtaining a building
permit. The construction drawings shall be drawn to an appro-
priate scale.
CONTROL. A manual or automatic device designed to regu-
late the gas, air, water or electrical supply to, or operation of, a
mechanical system.
CONVERSION BURNER. A burner designed to supply gas-
eous fuel to an appliance originally designed to utilize another
fuel.
COOKING APPLIANCE. See "Commercial cooking appH-
ances."
DAMPER. A manually or automatically controlled device to
regulate draft or the rate of flow of air or combustion gases.
Volume damper. A device that, when installed, will restrict,
retard or direct the flow of air in a duct, or the products of
combustion in a heat-producing appliance, its vent connec-
tor, vent or chimney therefrom.
DESIGN FLOOD ELEVATION. The elevation of the
"design flood," including wave height, relative to the datum
specified on the community's legally designated flood hazard
area map.
DESIGN WORKING PRESSURE. The maximum allow-
able working pressure for which a specific part of a system is
designed.
DIRECT REFRIGERATION SYSTEM. A system in which
the evaporator or condenser of the refrigerating system is in
direct contact with the air or other substances to be cooled or
heated.
DIRECT- VENT APPLIANCES. Appliances that are con-
structed and installed so that all air for combustion is derived
from the outdoor atmosphere and all flue gases are discharged
to the outdoor atmosphere. |
2007 OREGON MECHANICAL SPECIALTY CODE
13
DEFINITIONS
r. The pressure difference existing between the apph-
ance or any component part and the atmosphere, that causes a
continuous flow of air and products of combustion through the
gas passages of the appliance to the atmosphere.
IiradliLiiced draft. The pressure difference created by the
action of a fan, blower or ejector, that is located between the
appliance and the chimney or vent termination.
L The pressure difference created by a vent or
chimney because of its height, and the temperature differ-
ence between the flue gases and the atmosphere.
DRIP. The container placed at a low point in a system of piping
to collect condensate and from which the condensate is remov-
able.
DRY CLEANING SYSTEMS, Dry cleaning plants or sys-
tems are classified as follows:
je I. Those systems using Class I flammable liquid sol-
vents having a flash point below lOOT (38°C).
Type 11, Those systems using Class II combustible liquid
solvents having a flash point at or above 100°F (38°C) and
below 140°F (60°C).
Type III. Those systems using Class III combustible liquid
solvents having a flash point at or above 140°F (60°C).
Types IV aed ¥. Those systems using Class IV nonflamma-
ble liquid solvents.
BUCT. A tube or conduit utilized for conveying air. The air
passages of self-contained systems are not to be construed as
air ducts.
DUCT FURNACE. A warm-air furnace normally installed in
an air distribution duct to supply warm air for heating. This def-
inition shall apply only to a warm-air heating appliance that, for
air circulation, depends on a blower not furnished as part of the
furnace.
DUCT SYSTEM, A continuous passageway for the transmis-
sion of air that, in addition to ducts, includes duct fittings,
dampers, plenums, fans and accessory air-handling equipment
and appliances.
DWELLING. A building or portion thereof that contains not
more than two dwelling units.
DWELLING UNIT. A single unit providing complete, inde-
pendent living facilities for one or more persons, including per-
manent provisions for living, sleeping, eating, cooking and
sanitation.
ELECTRIC HEATING APPLIANCE. An appliance that
produces heat energy to create a warm environment by the
application of electric power to resistance elements, refrigerant
compressors or dissimilar material junctions.
ELECTRICAL CODE. The Oregon Electrical Specialty
Code.
ENERGY RECOVERY VENTILATION SYSTEM, Sys-
tems that employ air-to-air heat exchangers to recover energy
from or reject energy to exhaust air for the purpose of pre-heat-
ing, pre-cooling, humidifying or dehumidifying outdoor venti-
lation air prior to supplying such air to a space, either directly or
as part of an HVAC system.
AIR. Air that is conveyed to or from
occupied areas through ducts which are not part of the heating
or air-conditioning system, such as ventilation for human
usage, domestic kitchen range exhaust, bathroom exhaust and
domestic clothes dryer exhaust.
r. All piping, ducts, vents, control devices and
other components of systems other than appliances which are
permanently installed and integrated to provide control of envi-
ronmental conditions for buildings. This definition shall also
include other systems specifically regulated in this code.
EQUIPMENT, EXISTING. Any equipment regulated by this
code which was legally installed prior to the effective date of
this code, or for which a permit to install has been issued.
EVAPORATIVE COOLER. A device used for reducing the
sensible heat of air for cooling by the process of evaporation of
water into an airstream.
EVAPORATIVE COOLING SYSTEM. The equipment and
appliances intended or installed for the purpose of environmen-
tal coohng by an evaporative cooler from which the condi-
tioned air is distributed through ducts or plenums to the
conditioned area.
L That part of the system in which liquid
refrigerant is vaporized to produce refrigeration.
EXCESS AIR, The amount of air provided in addition to theo-
retical air to achieve complete combustion of a fuel, thereby
preventing the formation of dangerous products of combus-
tion.
EXHAUST SYSTEM. An assembly of connected ducts, ple-
nums, fittings, registers, grilles and hoods through which air is
conducted from the space or spaces and exhausted to the out-
door atmosphere.
L An assembly consisting of a hearth and fire
charriber of noncombustible material and provided with a
chimney, for use with solid fuels.
Factory-bmilt fireplace. A listed and labeled fireplace and
chimney system composed of factory-made components,
and assembled in the field in accordance with manufac-
turer's instructions and the conditions of the listing.
lace. A field-constructed fireplace com-
posed of solid masonry units, bricks, stones or concrete.
I. A free-standing chimney-connected
solid-fuel-buming heater, designed to be operated with the fire
chamber doors in either the open or closed position.
FLAME SAFEGUARD. A device that will automatically shut
off the fuel supply to a main burner or group of burners when
the means of ignition of such burners becomes inoperative, and
when flame failure occurs on the burner or group of burners.
Extra-heavy-duty cooking appliances include appliances uti-
lizing solid fuel such as wood, charcoal, briquettes, and mes-
quite to provide all or part of the heat source for cooking. |
FIRE CODE. As referenced in this code for construction,
alteration and repair of buildings and structures is the Oregon
Fire Code as adopted and amended by the State of Oregon Fire
Marshal.
14
2007 OREGON WiECHANICAL SPECIALTY CODE
DEFINITIONS
FLAME SPREAD INDEX. The numerical value assigned to
a material tested in accordance with ASTM E 84.
FLAMMABILITY CLASSIFICATION. Refrigerants shall
be assigned to one of the three classes — 1, 2 or 3 — in accor-
dance with ASHRAE 34. For Classes 2 and 3, the heat of com-
bustion shall be calculated assuming that combustion products
are in the gas phase and in their most stable state.
Class 1. Refrigerants that do not show flame propagation
when tested in air at 14.7 psia (101 kPa) and 70°F (21°C).
Class 2, Refrigerants having a lower flammability limit
(LFL) of more than 0.00625 pound per cubic foot (0.10
kg/m3) at 70°F (21°C) and 14.7 psia (101 kPa) and a heat of
combustion of less than 8,174 Btu/lb (19 000 kJ/kg).
Class 3. Refrigerants that are highly flammable, having a
LFL of less than or equal to 0.00625 pound per cubic foot
(0. 10 kg/m^) at 70T (2rC) and 14.7 psia (101 kPa) or a heat
of combustion greater than or equal to 8,174 Btu/lb (19 000
kJ/kg).
FLAMMABLE LIQUIDS. Any liquid that has a flash point
below 100°F (38°C), and has a vapor pressure not exceeding 40
psia (276 kPa) at 100°F (38°C). Flammable liquids shall be
known as Class I liquids and shall be divided into the following
classifications:
Class lA. Liquids having a flash point below 73°F (23°C)
and a boiling point below lOOT (38°C).
Class IB. Liquids having a flash point below 73°F (23°C)
and a boiling point at or above 100°F (38°C).
Class IC. Liquids having a flash point at or above 73°F
(23°C) and below 100°F (38°C).
FLAMMABLE VAPOR OR FUMES. Mixtures of gases in
air at concentrations equal to or greater than the LFL and less
than or equal to the upper flammability limit (UFL).
FLASH POINT. The minimum temperature corrected to a
pressure of 14.7 psia (101 kPa) at which the application of a test
flame causes the vapors of a portion of the sample to ignite
under the conditions specified by the test procedures and appa-
ratus. The flash point of a liquid shall be determined in accor-
dance with ASTM D 56, ASTM D 93 or ASTM D 3278.
FLOOR AREA, NET. The actual occupied area, not includ-
ing unoccupied accessory areas or thicknesses of walls.
FLOOR FURNACE. A completely self-contained furnace
suspended from the floor of the space being heated, taking air
for combustion from outside such space and with means for
observing flames and lighting the appliance from such space.
FLUE. A passageway within a chimney or vent through which
gaseous combustion products pass.
FLUE CONNECTION (BREECHING). A passage for con-
ducting the products of combustion from a fuel-fired appliance
to the vent or chimney (see also "Chimney connector" and
"Vent connector").
FLUE GASES. Products of combustion and excess air.
FLUE LINER (LINING). A system or material used to form
the inside surface of a flue in a chimney or vent, for the purpose
of protecting the surrounding structure from the effects of com-
bustion products and conveying combustion products without
leakage to the atmosphere.
FUEL GAS. A natural gas, manufactured gas, liquefied petro-
leum gas or a mixture of these.
FUEL OIL. Kerosene or any hydrocarbon oil having a flash
point not less than 100°F (38°C).
FUEL-OIL PIPING SYSTEM. A closed piping system that
connects a combustible liquid from a source of supply to a
fuel-oil-buming appliance.
FURNACE. A completely self-contained heating unit that is
designed to supply heated air to spaces remote from or adjacent
to the appliance location.
FURNACE ROOM. A room primarily utilized for the instal-
lation of fuel-burning, space-heating and water-heating appli-
ances other than boilers (see also "Boiler room").
FUSIBLE PLUG. A device arranged to relieve pressure by
operation of a fusible member at a predetermined temperature.
GROUND SOURCE HEAT PUMP LOOP SYSTEM. Pip-
ing buried in horizontal or vertical excavations or placed in a
body of water for the purpose of transporting heat transfer liq-
uid to and from a heat pump. Included in this definition are
closed loop systems in which the liquid is recirculated and open
loop systems in which the liquid is drawn from a well or other
source.
HAZARDOUS LOCATION. Any location considered to be a
fire hazard for flammable vapors, dust, combustible fibers or
other highly combustible substances. The location is not neces-
sarily categorized in the Building Code as a high-hazard use
group classification.
HEAT EXCHANGER. A device that transfers heat from one
medium to another.
HEAT PUMP. A refrigeration system that extracts heat from
one substance and transfers it to another portion of the same
substance or to a second substance at a higher temperature for a
beneficial purpose.
HEAT TRANSFER LIQUID. The operating or thermal stor-
age liquid in a mechanical system, including water Or other liq-
uid base, and additives at the concentration present under
operating conditions used to move heat from one location to
another. Refrigerants are not included as heat transfer liquids.
HEAVY-DUTY COOKING APPLIANCE. Heavy-duty
cooking appliances include electric under-fired broilers, elec-
tric chain (conveyor) broilers, gas under-fired broilers, gas
chain (conveyor) broilers, gas open-burner ranges (with or
without oven), electric and gas wok ranges, and electric and gas
over-fired (upright) broilers and salamanders.
HIGH-PROBABILITY SYSTEMS. A refrigeration system
in which the basic design or the location of components is such
that a leakage of refrigerant from a failed connection, seal or
component will enter an occupancy classified area, other than
the machinery room.
HIGH-SIDE PRESSURE. The parts of a refrigerafing system
subject to condenser pressure.
2007 OREGON MECHANICAL SPECIALTY CODE
15
DEFlWmOMS
An air-intake device used to capture by entrapment,
impingement, adhesion or similar means, grease and similar
contaminants before they enter a duct system.
Type I. A kitchen hood for collecting and removing grease
vapors and smoke.
[. A general kitchen hood for collecting and remov-
ing steam, vapor, heat and odors.
L A self-con-
tained package or factory-matched packages of integrated sys-
tems for generating gaseous hydrogen. Hydrogen generating
appliances utilize electrolysis, reformation, chemical, or other
processes to generate hydrogen.
L A flame, spark or hot surface capable
of igniting flammable vapors or fumes. Such sources include
appliance burners, burner ignitors and electrical switching
devices.
DANGEROUS TO LIFE OR HEALTH
(IDLH). The concentration of airborne contaminants that
poses a threat of death, immediate or delayed permanent
adverse health effects, or effects that could prevent escape from
such an environment. This contaminant concentration level is
established by the National Institute of Occupational Safety
and Health (NIOSH) based on both toxicity and flammability.
It is generally expressed in parts per million by volume (ppm
v/v) or milligrams per cubic meter (mg/m^).
ECT REFRIGERATION SYSTEM. A system in
which a secondary coolant cooled or heated by the refrigerat-
ing system is circulated to the air or other substance to be
cooled or heated. Indirect systems are distinguished by the
method of application shown below:
system. A system in which a secondary fluid is
either cooled or heated by the refrigerating system and then
circulated within a closed circuit in indirect contact with the
air or other substance to be cooled or heated.
-mdirect opee-spray system. A system in which
the secondary substance for an indirect open-spray system
is heated or cooled by an intermediate coolant circulated
from a second enclosure.
=spray system. A system in which a secondary cool-
ant is cooled or heated by the refrigerating system and then
circulated in direct contact with the air or other substance to
be cooled or heated.
Vented dosed system. A system in which a secondary cool-
ant is cooled or heated by the refrigerating system and then
passed through a closed circuit in the air or other substance
to be cooled or heated, except that the evaporator or con-
denser is placed in an open or appropriately vented tank.
JOINT, FLANGEB. A joint made by bolting together a pair of
flanged ends.
JOINT, FLARED. A metal-to-metal compression joint in
which a conical spread is made on the end of a tube that is com-
pressed by a flare nut against a mating flare.
JOINT, MECHANICAL. A general form of gas-tight joints
obtained by the joining of metal parts through a positive-hold-
ing mechanical construction, such as flanged joint, screwed
joint or flared joint.
JOINT, PLASTIC ADHESIVE. A joint made in tliermoset
plastic piping by the use of an adhesive substance which forms
a continuous bond between the mating surfaces without dis-
solving either one of them.
JOINT, PLASTIC HEAT FUSION. A joint made in thermo-
plastic piping by heating the parts sufficiently to permit fusion
of the materials when the parts are pressed together.
JOINT, PLASTIC SOLVENT CEMENT. A joint made in
thermoplastic piping by the use of a solvent or solvent cement
which forms a continuous bond between the mating surfaces.
JOINT, SOLDERED. A gas-tight joint obtained by the join-
ing of metal parts with metallic mixtures of alloys which melt at
temperatures between 400°F (204°C) and 1,000°F (538°C).
JOINT, WELDED. A gas-tight joint obtained by the joining
of metal parts in molten state.
LABELED. Devices, equipment, appliances or materials to
which have been affixed a label, seal, symbol or other identify-
ing mark of a nationally recognized testing laboratory, inspec-
tion agency or other organization concerned with product
evaluation that maintains periodic inspection of the production
of the above-labeled items and by whose label the manufac-
turer attests to compliance with applicable nationally recog-
nized standards.
LIGHT-DUTY COOKING APPLIANCE. Light-duty cook-
ing appliances include gas and electric ovens (including stan-
dard, bake, roasting, revolving, retherm, convection,
combination convection/steamer, conveyor, deck or deck-style
pizza, and pastry), electric and gas steam-jacketed kettles, elec-
tric and gas compartment steamers (both pressure and atmo-
spheric) and electric and gas cheesemelters.
LIMIT CONTROL. A device responsive to changes in pres-
sure, temperature or level for turning on, shutting off or throt-
tling the gas supply to an appliance.
LIMITED CHARGE SYSTEM. A system in which, with the
compressor idle, the design pressure will not be exceeded when
the refrigerant charge has completely evaporated.
LISTED. Equipment, appliances or materials included in a list
published by a nationally recognized testing laboratory,
inspection agency or other organization concerned with prod-
uct evaluation that maintains periodic inspection of production
of listed equipment, appliances or materials, and whose listing
states either that the equipment, appliances or material meets
nationally recognized standards or has been tested and found
suitable for use in a specified manner. Not all testing laborato-
ries, inspection agencies and other organizations concerned
with product evaluation use the same means for identifying
listed equipment, appliances or materials. Some do not recog-
nize equipment, appliances or materials as listed unless they
are also labeled. The authority having jurisdiction shall utilize
the system employed by the listing organization to identify a
listed product.
LIVING SPACE. Space within a dwelling unit utilized for liv-
ing, sleeping, eating, cooking, bathing, washing and sanitation
purposes.
16
2007 OREGON MECHANICAL SPECIALTY CODE
DEFINITIONS
LOWER EXPLOSIVE LIMIT (LEL). See "LFL."
LOWER FLAMMABLE LIMIT (LFL). The minimum con-
centration of refrigerant that is capable of propagating a flame
through a homogeneous mixture of refrigerant and air.
LOW-PRESSURE HOT- WATER-HEATING BOILER. A
boiler furnishing hot water at pressures not exceeding 160 psi
(1 103 kPa) and at temperatures not exceeding 250°F (121°C).
LOW-PRESSURE STEAM-HEATING BOILER. A boiler
furnishing steam at pressures not exceeding 15 psi (103 kPa).
LOW-PROBABILITY SYSTEMS. A refrigeration system in
which the basic design or the location of components is such
that a leakage of refrigerant from a failed connection, seal or
component will not enter an occupancy-classified area, other
than the machinery room.
LOW-SIDE PRESSURE. The parts of a refrigerating system
subject to evaporator pressure.
MACHINERY ROOM. A room meeting prescribed safety
requirements and in which refrigeration systems or compo-
nents thereof are located (see Sections 1105 and 1106).
MECHANICAL DRAFT SYSTEM. A venting system
designed to remove flue or vent gases by mechanical means,
that consists of an induced-draft portion under nonpositive
static pressure or a forced-draft portion under positive static
pressure.
Forced-draft venting system. A portion of a venting sys-
tem using a fan or other mechanical means to cause the
removal of flue or vent gases under positive static pressure.
Induced-draft venting system. A portion of a venting sys-
tem using a fan or other mechanical means to cause the
removal of flue or vent gases under nonpositive static vent
pressure.
Povt^er venting system. A portion of a venting system using
a fan or other mechanical means to cause the removal of flue
or vent gases under positive static vent pressure.
MECHANICAL EQUIPMENT/APPLIANCE ROOM. A
room or space in which nonfuel-fired mechanical equipment
and appliances are located.
MECHANICAL EXHAUST SYSTEM. A system for
removing air from a room or space by mechanical means.
MECHANICAL JOINT. A connection between pipes, fit-
tings, or pipes and fittings, which is neither screwed, caulked,
threaded, soldered, solvent cemented, brazed nor welded.
Also, a joint in which compression is applied along the center-
line of the pieces being joined. Some joints are part of a cou-
pling, fitting or adapter.
MECHANICAL SYSTEM. A system specifically addressed
and regulated in this code and composed of components,
devices, appliances and equipment.
MEDIUM-DUTY COOKING APPLIANCE. Medium-duty
cooking appliances include electric discrete element ranges
(with or without oven), electric and gas hot-top ranges, electric
and gas griddles, electric and gas double-sided griddles, elec-
tric and gas fryers (including open deep fat fryers, donut fryers,
kettle fryers, and pressure fryers), electric and gas pasta cook-
ers, electric and gas conveyor pizza ovens, electric and gas
tilting skillets (braising pans) and electric and gas rotisseries.
MODULAR BOILER. A steam or hot-water-heating assem-
bly consisting of a group of individual boilers called modules
intended to be installed as a unit with no intervening stop
valves. Modules are under one jacket or are individually jack-
eted. The individual modules shall be limited to a maximum
input rating of 400,000 Btu/h (117 228 W) gas, 3 gallons per
hour (gph) (11.4 L/h) oil, or 115 kW (electric).
NATURAL DRAFT SYSTEM. A venting system designed to
remove flue or vent gases under nonpositive static vent pres-
sure entirely by natural draft.
NATURAL VENTILATION. The movement of air into and
out of a space through intentionally provided openings, such as
windows and doors, or through nonpowered ventilators.
NONABRASIVE/ABRASIVE MATERIALS. Nonabrasive
particulate in high concentrations, moderately abrasive partic-
ulate in low and moderate concentrations, and highly abrasive
particulate in low concentrations, such as alfalfa, asphalt, plas-
ter, gypsum and salt.
NONCOMBUSTIBLE MATERIALS. Materials that, when
tested in accordance with ASTM E 136, have at least three of
four specimens tested meeting all of the following criteria:
1. The recorded temperature of the surface and interior
thermocouples shall not at any time during the test rise
more than 54°F (30°C) above the furnace temperature at
the beginning of the test.
2. There shall not be flaming from the specimen after the
first 30 seconds.
3. If the weight loss of the specimen during testing exceeds
50 percent, the recorded temperature of the surface and
interior thermocouples shall not at any time during the
test rise above the furnace air temperature at the begin-
ning of the test, and there shall not be flaming of the spec-
imen.
OCCUPANCY. The purpose for which a building, or portion
thereof, is utilized or occupied.
OFFSET (VENT). A combination of approved bends that
make two changes in direction bringing one section of the vent
out of line but into a line parallel with the other section.
OUTDOOR AIR. Air taken from the outdoors, and therefore
not previously circulated through the system.
OUTDOOR OPENING. A door, window, louver or skylight
openable to the outdoor atmosphere. |
OUTLET. A threaded connection or bolted flange in a piping
system to which a gas-burning appliance is attached.
PANEL HEATING. A method of radiant space heating in
which heat is supplied by large heated areas of room surfaces.
The heating element usually consists of warm water piping,
warm air ducts, or electrical resistance elements embedded in
or located behind ceiling, wall or floor surfaces.
PELLET FUEL-BURNING APPLIANCE. A closed-com-
bustion, vented appliance equipped with a fuel-feed mecha-
2007 OREGON MECHANICAL SPECIALTY CODE
17
DEFINITIONS
nism for burning processed pellets of solid fuel of a specified
size and composition.
i. To clear of air, water or other foreign substances.
J. Where used in this code, "piping" refers to either
pipe or tubing, or both.
Pipe. A rigid conduit of iron, steel, copper, brass or plastic.
Ibbimig. Semirigid conduit of copper, aluminum, plastic or
steel.
PLASTIC, THERMOPLASTIC. A plastic that is capable of
being repeatedly softened by increase of temperature and hard-
ened by decrease of temperature.
PLASTIC, THERMOSETTING, A plastic that is capable of
being changed into a substantially infusible or insoluble prod-
uct when cured under application of heat or chemical means.
PLENUM. An enclosed portion of the building structure,
other than an occupiable space being conditioned, that is
designed to allow air movement, and thereby serve as part of an
air distribution system.
PLUMBING CODE. The Oregon Plumbing Specialty Code.
PORTABLE FUEL CELL APPLIANCE. A fuel cell gener-
ator of electricity, which is not fixed in place. A portable fuel
cell appliance utihzes a cord and plug connection to a grid-iso-
lated load and has an integral fuel supply.
See "Boiler."
ISES. A lot, plot or parcel of land, including any struc-
ture thereon.
TEST. A test performed in the field to
prove system tightness.
PRESSURE-LIMITING DEVICE. A pressure-responsive
mechanism designed to stop automatically the operation of the
pressure-imposing element at a predetermined pressure.
PRESSURE RELIEF DEVICE. A pressure-actuated valve
or rupture member designed to relieve excessive pressure auto-
matically.
PRESSURE RELIEF VALVE. A pressure-actuated valve
held closed by a spring or other means and designed to relieve
pressure automatically in excess of the device's setting.
PRESSURE VESSELS. Closed containers, tanks or vessels
that are designed to contain liquids or gases, or both, under
pressure.
PRESSURE VESSELS— REFRIGERANT, Any refriger-
ant-containing receptacle in a refrigerating system. This does
not include evaporators where each separate section does not
exceed 0.5 cubic foot (0.014 m^) of refrigerant-containing vol-
ume, regardless of the maximum inside dimensions, evapora-
tor coils, controls, headers, pumps and piping.
ANCE). Any noncombustible assembly that is labeled or con-
structed in accordance with Table 308.6 and is placed between
combustible materials or assemblies and mechanical appli-
ances, devices or equipment, for the purpose of reducing
required airspace clearances. Protective assemblies attached
directly to a combustible assembly shall not be considered as
part of that combustible assembly.
VALVE. A valve that opens completely
by fast action, either manually or automatically controlled. A
valve requiring one-quarter round turn or less is considered to
be quick opening.
L A heater designed to transfer heat pri-
marily by direct radiation.
READY ACCESS (TO), That which enables a device, appli-
ance or equipment to be directly reached, without requiring the
removal or movement of any panel, door or similar obstruction
[see "Access (to)"].
A vessel permanently connected to a
refrigeration system by inlet and outlet pipes for storage of liq-
uid refrigerant.
L Air removed from a conditioned
space and intended for reuse as supply air.
RECLAIMED REFRIGERANTS. Refrigerants reprocessed
to the same specifications as for new refrigerants by means
including distillation. Such refrigerants have been chemically
analyzed to verify that the specifications have been met.
Reclaiming usually implies the use of processes or procedures
that are available only at a reprocessing or manufacturing facil-
ity.
^S. Refrigerants removed
from a system in any condition without necessarily testing or
processing them.
RECYCLED REFRIGERANTS. Refrigerants from which
contaminants have been reduced by oil separation, removal of
noncondensable gases, and single or multiple passes through
devices that reduce moisture, acidity and particulate matter,
such as replaceable core filter driers. These procedures usually
are performed at the field job site or in a local service shop.
r. A substance utilized to produce refrigera-
tion by its expansion or vaporization.
REFRIGERANT SAFETY CLASSIFICATIONS. Group-
ings that indicate the toxicity and flammability classes in
accordance with Section 1103.1. The classification group is
made up of a letter (A or B) that indicates the toxicity class, fol-
lowed by a number (1, 2 or 3) that indicates the flammability
class. Refrigerant blends are similarly classified, based on the
compositions at their worst cases of fractionation, as separately
determined for toxicity and flammability. In some cases, the
worst case of fractionation is the original formulation.
Class 1 indicates refrigerants that do not
show flame propagation in air when tested by prescribed
methods at specified conditions. Classes 2 and 3 signify
refrigerants with "lower flammability" and "higher
flammability," respectively; the distinction depends on both
the LFL and heat of combustion.
Toxicity. Classes A and B signify refrigerants with "lower
toxicity" and "higher toxicity," respectively, based on pre-
scribed measures of chronic (long-term, repeated expo-
sures) toxicity.
I. A room or space in
which an evaporator or brine coil is located for the purpose of
18
2007 OREGON WJECHANICAL SPECIALTY CODE
DEFINITIONS
reducing or controlling the temperature within the room or
space to below 68°F (20°C).
REFRIGERATING SYSTEM. A combination of intercon-
nected refrigerant-containing parts constituting one closed
refrigerant circuit in which a refrigerant is circulated for the
purpose of extracting heat.
REFRIGERATION CAPACITY RATING. Expressed as 1
horsepower (0.75 kW), 1 ton or 12,000 Btu/h (3.5 kW), shall all
mean the same quantity.
REFRIGERATION MACHINERY ROOM. See "Machin-
ery room."
REFRIGERATION SYSTEM, ABSORPTION. A heat-
operated, closed-refrigeration cycle in which a secondary fluid
(the absorbent) absorbs a primary fluid (the refrigerant) that
has been vaporized in the evaporator.
Direct system. A system in which the evaporator is in direct
contact with the material or space refrigerated, or is located
in air-circulating passages communicating with such
spaces.
Indirect system. A system in which a brine coil cooled by
the refrigerant is circulated to the material or space refriger-
ated, or is utilized to cool the air so circulated. Indirect sys-
tems are distinguished by the type or method of application.
REFRIGERATION SYSTEM CLASSIFICATION.
Refrigeration systems are classified according to the degree of
probability that leaked refrigerant from a failed connection,
seal or component will enter an occupied area. The distinction
is based on the basic design or location of the components.
REFRIGERATION SYSTEM, MECHANICAL. A combi-
nation of interconnected refrigeration-containing parts consti-
tuting one closed refrigerant circuit in which a refrigerant is
circulated for the purpose of extracting heat and in which a
compressor is used for compressing the refrigerant vapor.
REFRIGERATION SYSTEM, SELF-CONTAINED. A
complete factory-assembled and tested system that is shipped
in one or more sections and has no refrigerant-containing parts
that are joined in the field by other than companion or block
valves.
REGISTERED DESIGN PROFESSIONAL. An individual
who is registered or licensed to practice their respective design
profession as defined by the statutory requirements of the pro-
fessional registration laws of the state or jurisdiction in which
the project is to be constructed.
RETURN AIR. Air removed from an approved conditioned
space or location and recirculated or exhausted.
RETURN AIR SYSTEM. An assembly of connected ducts,
plenums, fittings, registers and grilles through which air from
the space or spaces to be heated or cooled is conducted back to
the supply unit (see also "Supply air system").
ROOM HEATER VENTED. A free-standing heating unit
burning solid or liquid fuel for direct heating of the space in and
adjacent to that in which the unit is located.
SAFETY VALVE. A valve that relieves pressure in a steam
boiler by opening fully at the rated discharge pressure. The
valve is of the spring-pop type.
SELF-CONTAINED EQUIPMENT. Complete, fac-
tory-assembled and tested, heating, air-conditioning or refrig-
eration equipment installed as a single unit, and having all
working parts, complete with motive power, in an enclosed unit
of said machinery.
SHAFT. An enclosed space extending through one or more
stories of a building, connecting vertical openings in succes-
sive floors, or floors and the roof.
SHAFT ENCLOSURE. The walls or construcdon forming
the boundaries of a shaft.
SLEEPING UNIT. A room or space in which people sleep,
which can also include permanent provisions for living, eating,
and either sanitation or kitchen facilities but not both. Such
rooms and spaces that are also part of a dwelling unit are not
sleeping units.
SMOKE DAMPER. A listed device that is designed to resist
the passage of air and smoke. The device is arranged to operate
automatically, controlled by a smoke detection system, and
when required, is capable of being positioned manually from a
remote command station.
SMOKE-DEVELOPED INDEX. A numerical value
assigned to a material tested in accordance with ASTM E 84.
SOLID FUEL (COOKING APPLICATIONS). Applicable
to commercial food service operations only, solid fuel is any
bulk material such as hardwood, mesquite, charcoal or bri-
quettes that is combusted to produce heat for cooking opera-
tions.
SOURCE CAPTURE SYSTEM. A mechanical exhaust sys-
tem designed and constructed to capture air contaminants at
their source and to exhaust such contaminants to the outdoor
atmosphere.
STATIONARY FUEL CELL POWER PLANT. A self-con-
tained package or factory-matched packages which constitute
an automatically operated assembly of integrated systems for
generating useful electrical energy and recoverable thermal
energy that is permanently connected and fixed in place.
STEAM-HEATING BOILER. A boiler operated at pressures
not exceeding 15 psi (103 kPa) for steam.
STOP VALVE. A shutoff valve for controUing the flow of Hq-
uid or gases.
STORY. That portion of a building included between the upper
surface of a floor and the upper surface of the floor next above,
except that the topmost story shall be that portion of a building
included between the upper surface of the topmost floor and the
ceiling or roof above.
STRENGTH, ULTIMATE. The highest stress level that the
component will tolerate without rupture.
SUPPLY AIR. That air delivered to each or any space supplied
by the air distribution system or the total air delivered to all
spaces supplied by the air distribution system, which is pro-
vided for ventilating, heating, cooling, humidification,
dehumidification and other similar purposes.
SUPPLY AIR SYSTEM. An assembly of connected ducts,
plenums, fittings, registers and grilles through which air.
2007 OREGON MECHANICAL SPECIALTY CODE
19
DEFINITIONS
>l
heated or cooled, is conducted from the supply unit to the space
or spaces to be heated or cooled (see also "Return air system").
THEORETICAL AIR. The exact amount of air required to
supply oxygen for complete combustion of a given quantity of
a specific fuel.
THERMAL RESISTANCE (R\ A measure of the ability to
retard the flow of heat. The i?- value is the reciprocal of thermal
conductance.
TLV-TWA(THRESHOLD LIMIT VALUE-TIME-
WEIGHTEB AVERAGE). The time-weighted average con-
centration of a refrigerant or other chemical in air for a normal
8-hour workday and a 40-hour workweek, to which nearly all
workers are repeatedly exposed, day after day, without adverse
effects, as adopted by the American Conference of Govern-
ment Industrial Hygienists (ACGIH).
TOILET ROOM. A room containing a water closet and, fre-
quently, a lavatory, but not a bathtub, shower, spa or similar
bathing fixture.
TOXICITY CLASSIFICATION. Refrigerants shall be clas-
sified for toxicity to one of two classes in accordance with
ASHRAE 34:
Class A. Refrigerants for which toxicity has not been identi-
fied at concentrations less than or equal to 400 parts per mil-
lion (ppm), based on data used to determine Threshold
Limit Value-Time-Weighted Average (TLV-TWA) or con-
sistent indices.
Class B. Refrigerants for which there is evidence of toxicity
at concentrations below 400 ppm, based on data used to
determine TLV-TWA or consistent indices.
TRANSITION FITTINGS, PLASTIC TO STEEL. An
adapter for joining plastic pipe to steel pipe. The purpose of this
fitting is to provide a permanent, pressure-tight connection
between two materials which cannot be joined directly one to
another.
UNCONFINED SPACE. A space having a volume not less
than 50 cubic feet per 1 ,000 Btu/h (4.8 m^/kW) of the aggregate
input rating of all appliances installed in that space. Rooms
communicating directly with the space in which the appliances
are installed, through openings not furnished with doors, are
considered a part of the unconfined space.
UNIT HEATER. A self-contained appliance of the fan type,
designed for the delivery of warm air directly into the space in
which the appliance is located.
UNUSUALLY TIGHT CONSTRUCTION. Construction
meeting the following requirements:
1 . Walls exposed to the outdoor atmosphere having a con-
tinuous air barrier with openings gasketed or sealed;
2. Weatherstripping on openable windows and doors; and
3. Caulking or sealants are applied to areas, such as joints
around window and door frames, between sole plates
and floors, between wall-ceiling joints, between wall
panels, at penetrations for plumbing, electrical and gas
lines and at other openings.
A building of ordinary tightness is one which does not meet
the definition of unusually tight construction.
VENT. A pipe or other conduit composed of factory-made
components, containing a passageway for conveying combus-
tion products and air to the atmosphere, listed and labeled for
use with a specific type or class of appliance.
Pellet vent. A vent listed and labeled for use with listed pel-
let-fuel-buming appliances.
L vent. A vent listed and labeled for use with the fol-
lowing:
1. Oil-burning appliances that are listed for use with
Type L vents.
2. Gas-fired appliances that are listed for use with Type
B vents.
VENT CONNECTOR. The pipe that connects an approved
fuel-fired appliance to a vent.
VENT DAMPER DEVICE, AUTOMATIC. A device
intended for installation in the venting system, in the outlet of
an individual automatically operated fuel-burning appliance
that is designed to open the venting system automatically when
the appliance is in operation and to close off the venting system
automatically when the appliance is in a standby or shutdown
condition.
VENTILATION. The natural or mechanical process of sup-
plying conditioned or unconditioned air to, or removing such
air from, any space.
VENTILATION AIR. That portion of supply air that comes
from the outside (outdoors), plus any recirculated air that has
been treated to maintain the desired quality of air within a des-
ignated space.
VENTING SYSTEM. A continuous open passageway from
the flue collar of an appliance to the outside atmosphere for the
purpose of removing flue or vent gases. A venting system is
usually composed of a vent or a chimney and vent connector, if
used, assembled to form the open passageway.
VESTIBULE. A passage, hall or chamber between the outer
door and the interior of a building.
WATER HEATER. Appliances which heat potable water and
are equipped with approved safety devices and operate at or
below all of the following:
1. Volume of 120 gallons (454 L);
2. Water temperature of 210°F (98.9°C);
3. 150 pounds (1031 kPa) per square inch operating pres-
sure; and
4. With 200,000 Btu (58 620 W) input.
20
2007 OREGON MECHANICAL SPECIALTY CODE
CHAPTER 3
GENERAL REGULATIONS
SECTION 301
GENERAL
301.1 Scope. This chapter shall goyem the approval and instal-
lation of all equipment and appliances that comprise parts of
the building mechanical systems regulated by this code in
accordance with Section 101.2.
Equipment shall not be installed, altered or used in violation
of this code. The fuel input rate to equipment shall be increased
in excess of the approved Btu/h (W) rating at the altitude where
it is being used.
301.2 Energy utilization. Heating, ventilating and air-condi-
tioning systems of all structures shall be designed and installed
for efficient utilization of energy in accordance with Chapter
13 of the Oregon Structural Specialty Code.
301.3 Fuel gas appliances and equipment. The approval and
installation of fuel gas distribution piping and equipment, fuel
gas-fired appliances and fuel gas-fired appliance venting sys-
I tems shall be in accordance with Appendix C.
301.4 Listed and labeled. Appliances regulated by this code
I shall be listed and labeled for the application in which they are
I installed and used, unless otherwise approved in accordance
with Section 105.
Exception: Listing and labeling of appliances used for
refrigeration shall be in accordance with Section 1101.2.
301.5 Labeling. Labeling shall be in accordance with the pro-
cedures set forth in Sections 301.5.1 through 301.5.2.3.
301.5.1 Testing. An approved agency shall test a represen-
tative sample of the mechanical equipment and appliances
being labeled to the relevant standard or standards. The
approved agency shall mairitain a record of all of the tests
performed. The record shall provide sufficient detail to ver-
ify compliance with the test standard.
301.5.2 Inspection and identification. The approved
agency shall periodically perform an inspection, which
shall be in-plant if necessary, of the mechanical equipment
and appliances to be labeled. The inspection shall verify that
the labeled mechanical equipment arid appliances are repre-
sentative of the mechanical equipment and appliances
tested.
301.5.2.1 Independent. The agency to be approved shall
be objective and competent. To confirm its objectivity,
the agency shall disclose all possible conflicts of interest.
301.5.2.2 Equipment. An approved agency shall have
adequate equipment to perform all required tests. The
equipment shall be periodically calibrated.
301.5.2.3 Personnel. An approved agency shall employ
experienced personnel educated in conducting, supervis-
ing and evaluating tests.
301.6 Label information. A permanent factory-applied
name-plate(s) shall be affixed to appliances on which shall
appear in legible lettering, the manufacturer's name or trade-
mark, the model number, serial number and the seal or mark of
the approved agency. A label shall also include the following:
1. Electrical equipment and appliances: Electrical rating in
volts, amperes and motor phase; identification of indi-
vidual electrical components in volts, amperes or watts,
motor phase; Btu/h (W) output; and required clearances.
2. Absorption units: Hourly rating in Btu/h (W); minimum
hourly rating for units having step or automatic modulat-
ing controls; type of fuel; type of refrigerant; cooling
capacity in Btu/h (W); and required clearances.
3. Fuel-burning units: Hourly rating in Btu/h (W); type of
fuel approved for use with the appliance; and required
clearances.
4. Electric comfort heating appliances: Name and
trade-mark of the manufacturer; the model number or
equivalent; the electric rating in volts, ampacity and
phase; Btu/h (W) output rating; individual marking for
each electrical component in amperes or watts, volts and
phase; required clearances from combustibles; and a seal
indicating approval of the appliance by an approved
agency.
Note: For reference only. Not adopted as part of this code.
Wood stoves, as defined by the Oregon Department of Environ-
mental Quality OAR Chapter 340, Division 34, are required by
DEQ to bear a certification label.
301.7 Electrical. Electrical wiring, controls and connections
to equipment and appliances regulated by this code shall be in
accordance with the Electrical Code.
301.8 Plumbing connections. Potable water supply and build-
ing drainage system connections to equipment and appliances
regulated by this code shall be in accordance with the Plumbing
Code.
301.9 Fuel types. Fuel-fired apphances shall be designed for
use with the type of fuel to which they will be connected and the
altitude at which they are installed. Appliances that comprise
parts of the building mechanical system shall not be converted
for the usage of a different fuel, except where approved and
converted in accordance with the manufacturer's instructions.
The fuel input rate shall not be increased or decreased beyond
the limit rating for the altitude at which the appliance is
installed.
301.10 Vibration isolation. Where vibration isolation of
equipment and appliances is employed, an approved means of
supplemental restraint shall be used to accomplish the support
and restraint.
2007 OREGON MECHANICAL SPECIALTY CODE
21
GENERAL REGULATIONS
301.11 Repair. Defective material or parts shall be replaced or
repaired in such a manner so as to preserve the original
approval or listing.
301.12 Wind resistance. Mechanical equipment, appliances
and supports that are exposed to wind shall be designed and
installed to resist the wind pressures determined in accordance
with the Building Code.
hazard. For structures located in flood hazard
areas, as identified by the local jurisdiction, mechanical sys-
tems, equipment and appliances shall be located at or above the
design flood elevation.
Exceptions Mechanical systems, equipment and appliances
are permitted to be located below the design flood elevation
provided that they are designed and installed to prevent
water from entering or accumulating within the components
and to resist hydrostatic and hydrodynamic loads and
stresses, including the effects of buoyancy, during the
occurrence of flooding to the design flood elevation in com-
pliance with the flood-resistant construction requirements
of the Building Code.
3.1 High-velocity wave action. In flood hazard areas
subject to high-velocity wave action, mechanical systems
and equipment shall not be mounted on or penetrate walls
intended to break away under flood loads.
301.14 Modentproofing. Buildings or structures and the walls
enclosing habitable or occupiable rooms and spaces in which
persons live, sleep or work, or in which feed, food or foodstuffs
are stored, prepared, processed, served or sold, shall be con-
structed to protect against the entrance of rodents in accordance
with the Building Code.
301.15 Seismic resistance. When earthquake loads are appli-
cable in accordance with the Building Code, mechanical sys-
tem supports shall be designed and installed for the seismic
forces in accordance with the Building Code.
SECTION 302
PROTECTION OF STRUCTURE
.1 Structural safety. The building or structure shall not be
weakened by the installation of mechanical systems. Where
floors, walls, ceilings or any other portion of the building or
structure are required to be altered or replaced in the process of
installing or repairing any system, the building or structure
shall be left in a safe structural condition in accordance with the
Building Code.
302.2 Penetrations of floor/ceiling assemblies and
ISre-resistance-rated assemblies. Penetrations of floor/ceil-
ing assemblies and assemblies required to have a fire-resis-
tance rating shall be protected in accordance with the Building
Code.
302.3 Cutting, notching and boring in wood framing. The
cutting, notching and boring of wood framing members shall
comply with Sections 302.3.1 through 302.3.4.
302.3.1 Joist notching. Notches on the ends of joists shall
not exceed one-fourth the joist depth. Holes bored in joists
shall not be within 2 inches (5 1 mm) of the top or bottom of
the joist, and the diameter of any such hole shall not exceed
one-third the depth of the joist. Notches in the top or bottom
of joists shall not exceed one- sixth the depth and shall not be
located in the middle third of the span.
302.3.2 Stud cutting and notching. In exterior walls and
bearing partitions, any wood stud is permitted to be cut or
notched not to exceed 25 percent of its depth. Cutting or
notching of studs not greater than 40 percent of their depth is
permitted in nonbearing partitions supporting no loads
other than the weight of the partition.
302.3.3 Bored holes. A hole not greater in diameter than 40
percent of the stud depth is permitted to be bored in any
wood stud. Bored holes not greater than 60 percent of the
depth of the stud are permitted in nonbearing partitions or in
any wall where each bored stud is doubled, provided not
more than two such successive doubled studs are so bored.
In no case shall the edge of the bored hole be nearer than
0.625 inch (15.9 mm) to the edge of the stud. Bored holes
shall not be located at the same section of stud as a cut or
notch.
302.3.4 Engineered wood products. Cuts, notches and
holes bored in trusses, structural composite veneer lumber,
structural glue-laminated members and I-joists are prohib-
ited except where permitted by the manufacturer's recom-
mendations or where the effects of such alterations are
specifically considered in the design of the member.
302.4 Alterations to trusses. Truss members and components
shall not be cut, drilled, notched, spliced or otherwise altered in
any way without written concurrence and approval of a regis-
tered design professional. Alterations resulting in the addition of
loads to any member (e.g., HVAC equipment, water heaters)
shall not be permitted without verification that the truss is capa-
ble of supporting such additional loading.
302.5 Cutting, notching and boring in steel framing. The
cutting, notching and boring of steel framing members shall
comply with Sections 302.5.1 through 302.5.3.
302.5.1 Cutting, notching and boring holes in structural
steel framing. The cutting, notching and boring of holes in
structural steel framing members shall be as prescribed by
the registered design professional.
302.5.2 Cutting, notching and boring holes in
cold-formed steel framing. Flanges and lips of load-bear-
ing cold-formed steel framing members shall not be cut or
notched. Holes in webs of load-bearing cold-formed steel
framing members shall be permitted along the centerline of
the web of the framing member and shall not exceed the
dimensional limitations, penetration spacing or minimum
hole edge distance as prescribed by the registered design
professional. Cutting, notching and boring holes of steel
floor/roof decking shall be as prescribed by the registered
design professional.
302.5.3 Cutting, notching and boring holes in
nonstructural cold-formed steel wall framing. Flanges
and lips of nonstructural cold- formed steel wall studs shall
not be cut or notched. Holes in webs of nonstructural
cold-formed steel wall studs shall be permitted along the
center-line of the web of the framing member, shall not
22
2007 OREGON MECHANICAL SPECIALTY CODE
GENERAL REGULATIONS
exceed 1 .5 inches (38 mm) in width or 4 inches (102 mm) in
length, and shall not be spaced less than 24 inches (610 mm)
center to center from another hole or less than 10 inches
(254 mm) from the bearing end.
SECTION303
EQUIPMENT AND APPLIANCE LOCATION
303.1 General. Equipment and appliances shall be located as
required by this section, specific requirements elsewhere in this
code and the conditions of the equipment and appliance listing.
303.2 Hazardous locations. Appliances shall not be located in
a hazardous location unless listed and approved for the specific
installation.
303.3 Prohibited locations. Fuel-fired appliances shall not be
located in, or obtain combustion air from, any of the following
rooms or spaces:
1. Sleeping rooms.
2. Bathrooms.
3. Toilet rooms.
4. Storage closets.
5. Surgical rooms.
Exception: This section shall not apply to the following
appliances:
1 . Direct-vent appliances that obtain all combustion air
directly from the outdoors.
2. Solid fuel-fired appliances, provided that the room is
not a confined space and the building is not of unusu-
ally tight construction.
3. Appliances installed in a dedicated enclosure in
which all combustion air is taken directly from the
outdoors, in accordance with Section 703. Access to
such enclosure shall be through a solid,
> weather-stripped door equipped with an approved
self-closing device.
303.4 Protection from damage. Appliances shall not be
installed in a location where subject to mechanical damage
unless protected by approved barriers.
•
.5 Indoor locations. Fuel-fired furnaces and boilers
installed in closets and alcoves shall be listed for such installa-
tion. For purposes of this section, a closet or alcove shall be
defined as a room or space having a volume less than 12 times
the total volume of fuel-fired appliances other than boilers and
less than 16 times the total volume of boilers. Room volume
shall be computed using the gross floor area and the actual ceil-
ing height up to a maximum computation height of 8 feet (2438
mm).
303.6 Outdoor locations. Appliances installed in other than
indoor locations shall be listed and labeled for outdoor installa-
tion.
303.7 Pit locations. Appliances installed in pits or excavations
shall not come in direct contact with the surrounding soil. The
sides of the pit or excavation shall be held back a minimum of
12 inches (305 mm) from the appliance. Where the depth
exceeds 12 inches (305 mm) below adjoining grade, the walls
of the pit or excavation shall be lined with concrete or masonry.
Such concrete or masonry shall extend a minimum of 4 inches
(102 mm) above adjoining grade and shall have sufficient lat-
eral load-bearing capacity to resist collapse. The appliance
shall be protected from flooding in an approved manner.
303.8 Elevator shafts. Mechanical systems shall not be
located in an elevator shaft.
SECTION 304
INSTALLATION
304.1 General. Equipment and appliances shall be installed as
required by the terms of their approval, in accordance with the
conditions of the listing, the manufacturer's installation
instructions and this code. Manufacturer's installation instruc-
tions shall be available on the job site at the time of inspection.
304.2 Conflicts. Where conflicts between this code and the
conditions of listing or the manufacturer's installation instruc-
tions occur, the provisions of this code shall apply.
Exception: Where a code provision is less restrictive than
the conditions of the listing of the equipment or appliance or
the manufacturer's installation instructions, the conditions
of the listing and the manufacturer's installation instructions
shall apply.
304.3 Elevation of ignition source. Heating and/or cooling
equipment and water heaters covered by this code, located in a
garage and which generate a glow, spark or flame capable of
igniting flammable vapors, shall be installed with sources of
ignition at least 18 inches (457 mm) above the floor level.
304.3.1 Parking garages. Connection of a parking garage
with any room in which there is a fuel-fired appliance shall
be by means of a vestibule providing a two-doorway separa-
tion, except that a single door is permitted where the sources
of ignition in the appliance are elevated in accordance with
Section 304.3.
Exception: This section shall not apply to appliance
installations complying with Section 304.5.
[EG] 304.4 Hydrogen-generating and refueling operations.
Ventilation shall be required in accordance with Section
304.4.1, 304.4.2 or 304.4.3 in public garages, private garages,
repair garages, automotive service stations and parking
garages that contain hydrogen-generating appliances or refuel-
ing systems. For the purpose of this section, rooms or spaces
that are not part of the living space of a dwelling unit and that
communicate directly with a private garage through openings
shall be considered to be part of the private garage.
[EG] 304.4.1 Natural ventilation. Indoor locations
intended for hydrogen-generating or refueling operations
shall be limited to a maximum floor area of 850 square feet
(79 m^) and shall communicate with the outdoors in accor-
dance with Sections 304.4. 1 . 1 through 304.4. 1 .2. The maxi-
mum rated output capacity of hydrogen generating
appliances shall not exceed 4 standard cubic feet per minute
(0.00189 mVs) of hydrogen for each 250 square feet (23.2
m^) of floor area in such spaces. The minimum cross-sec-
tional dimension of air openings shall be 3 inches (76 mm).
2007 OREGON MECHANICAL SPECIALTY CODE
23
GENERAL REGULATIONS
Where ducts are used, they shall be of the same cross-sec-
tional area as the free area of the openings to which they
connect. In such locations, equipment and appliances hav-
ing an ignition source shall be located such that the source of
ignition is not within 12 inches (305 mm) of the ceiling.
1.4.1.1 Two openings. Two permanent openings
shall be provided within the garage. The upper opening
shall be located entirely within 12 inches (305 mm) of the
ceiling of the garage. The lower opening shall be located
entirely within 12 inches (305 mm) of the floor of the
garage. Both openings shall be provided in the same
exterior wall. The openings shall communicate directly
with the outdoors and shall have a minimum free area of
V2 square foot per 1,000 cubic feet (1 m7610 m^) of
garage volume.
[FG] 304.4.1.2 Louvers and grilles. In calculating free
area required by Section 304.4.1, the required size of
openings shall be based on the net free area of each
opening. If the free area through a design of louver or
grille is known, it shall be used in calculating the size
opening required to provide the free area specified. If
the design and free area are not known, it shall be
assumed that wood louvers will have 25 percent free
area and metal louvers and grilles will have 75 percent
free area. Louvers and grilles shall be fixed in the open
position.
[FG] 304.4.2 Mechanical ventilation. Indoor locations
intended for hydrogen-generating or refueling operations
shall be ventilated in accordance with Section 502.16. In
such locations, equipment and apphances having an igni-
tion source shall be located such that the source of ignition is
below the mechanical ventilation outlet(s).
[FG] 304.4.3 Specially engineered installations. As an
alternative to the provisions of Sections 304.4. 1 and 304.4.2
the necessary supply of air for ventilation and dilution of
flammable gases shall be provided by an approved engi-
neered system.
304.5 Public garages. Appliances located in public garages,
motor fueling dispensing facilities, repair garages or other
areas frequented by motor vehicles, shall be installed a mini-
mum of 8 feet (2438 mm) above the floor. Where motor vehi-
cles exceed 6 feet (1829 mm) in height and are capable of
passing under an apphance, appliances shall be installed a min-
imum of 2 feet (610 mm) higher above the floor than the height
of the tallest vehicle.
304.6 Private garages. Appliances located in private garages
and car]3orts shall be installed with a minimum clearance of 6
feet (1829 mm) above the floor.
Exception: The requirements of this section shall not apply
where the appliances are protected from motor vehicle
impact and installed in accordance with Section 304.3 and
Figure 304.1.
304.7 Construction and protection. Boiler rooms and fur-
nace rooms shall be protected as required by the Building
Code.
304.8 Clearances to combustible construction. Heat-pro-
ducing equipment and appliances shall be installed to maintain
the required clearances to combustible construction as speci-
fied in the listing and manufacturer's instructions. Such clear-
ances shall be reduced only in accordance with Section 308.
Clearances to combustibles shall include such considerations
as door swing, drawer pull, overhead projections or shelving
and window swing, shutters, coverings and drapes. Devices
such as doorstops or limits, closers, drapery ties or guards shall
not be used to provide the required clearances.
304.9 Clearances from grade. Equipment and appliances
installed at grade level shall be supported on a level concrete
slab or other approved material extending above adjoining
grade or shall be suspended a minimum of 6 inches (152 mm)
above adjoining grade.
304.10 Guards. Guards shall be provided where appliances,
equipment, fans or other components that require service are
located within 10 feet (3048 mm) of a roof edge or open side of
a walking surface and such edge or open side is located more
than 30 inches (762 mm) above the floor, roof or grade below.
The guard shall extend not less than 30 inches (762 mm)
beyond each end of such appliances, equipment, fans, compo-
nents and the top of the guard shall be located not less than 42
inches (1067 mm) above the elevated surface adjacent to the
guard. The guard shall be constructed so as to prevent the pas-
sage of a 21 -inch-diameter (533 mm) sphere and shall comply
with the loading requirements for guards specified in the Build-
ing Code.
Exception: The section shall not apply to the replacement,
repair or maintenance of an existing appliance or piece of
equipment lawfully in existence at the time of the adoption
of this code.
Exception: The requirements of this section shall not apply
where the appliances are protected from motor vehicle
impact and installed in accordance with Section 304.3 and
Figure 304.1.
304.11 Area served. Appliances serving different areas of a
building other than where they are installed shall be perma-
nently marked in an approved manner that uniquely identifies
the appliance and the area it serves.
24
2007 OREGON MECHANICAL SPECIALTY CODE
.^
c
CO
(0
O
<
m
X
o
r-
m
>o
■^ 30
> m
SE
m
o
O
Examples of barrier locations, when appliances are
in the path of vehicles
^Minimum 2" sch. 40 iron pipe-
filled witli concrete
Furnace
Option 2:
Wheel Barrier. -.
Veliicle
1
For appliances not In tlie path of the
vehicles, this bollard is optional
Vehicle
2
Wheel Barrier
(Option 2)
Bolt to slab
(Option 3)
For retro installations
2" Dia. min.
Steel Sch. 40 pipe or tube
>
2"
>Y'
<
9
6"
e
^
*-1
-^
-«
8" "
36"
J pohcretejslab
^11 I u.
GENERAL REGULATIONS
SECTION 305
PIPING SUPPORT
305.1 General. All mechanical system piping shall be sup-
ported in accordance with this section.
305.2 Materials. Pipe hangers and supports shall have suffi-
cient strength to withstand all anticipated static and specified
dynamic loading conditions associated with the intended use.
Pipe hangers and supports that are in direct contact with piping
shall be of approved materials that are compatible with the pip-
ing and that will not promote galvanic action.
305.3 Structural attachment. Hangers and anchors shall be
attached to the building construction in an approved manner.
305.4 Interval of support. Piping shall be supported at dis-
tances not exceeding the spacing specified in Table 305.4, or in
accordance with MSS SP-69.
TABLE 305.4
PIPING SUPPORT SPACING^
PIPING MATERIAL
MAXIMUM
HORIZONTAL
SPACING
(feet)
MAXIMUM
VERTICAL
SPACING
(feet)
ABS pipe
4
10^
Aluminum pipe and tubing
10
15
Brass pipe
10
10
Brass tubing, 1 V4-inch diameter
and smaller
6
10
Brass tubing, 1 Vj-inch diameter
and larger
10
10
Cast-iron pipe''
5
15
Copper or copper-alloy pipe
12
10
Copper or copper-alloy tubing,
1 V4-inch diameter and smaller
6
10
Copper or copper-alloy tubing,
1 V2-inch diameter and larger
10
10
CPVC pipe or tubing, 1 inch
and smaller
3
10^=
CPVC pipe or tubing 1 '/4-inch
and larger
4
10=
Lead pipe
Continuous
4
PB pipe or tubing
2%
(32 inches)
4
PEX tubing
2%
(32 inches)
10=
PVC pipe
4
10=
Steel tubing
8
10
Steel pipe
12
15
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
a. See Section 301.15.
b. The maximum horizontal spacing of cast-iron pipe hangers shall be
increased to 10 feet where| 10-foot lengths of pipe are installed.
c. Mid-story guide.
305.5 Protection against physical damage. In concealed
locations where piping, other than cast-iron or steel, is installed
through holes or notches in studs, joists, rafters or similar mem-
bers less than 1.5 inches (38 mm) from the nearest edge of the
member, the pipe shall be protected by shield plates. Protective
shield plates shall be a minimum of 0.062-inch-thick (1.6 mm)
steel, shall cover the area of the pipe where the member is
notched or bored, and shall extend a minimum of 2 inches (5 1
mm) above sole plates and below top plates.
SECTION 306
ACCESS AND SERVICE SPACE
306.1 Clearances for maintenance and replacement. Clear-
ances around appliances to elements of permanent construc-
tion, including other installed equipment and appliances, shall
be sufficient to allow inspection, service, repair or replacement
without removing such elements of permanent construction or
disabling the function of a required fire-resistance-rated
assembly.
306.1.1 Central furnaces. Central furnaces within com-
partments or alcoves shall have a minimum working space
clearance of 3 inches (76 mm) along the sides, back and top
with a total width of the enclosing space being at least 12
inches (305 mm) wider than the furnace. Furnaces having a
firebox open to the atmosphere shall have at least 6 inches
(152 mm) working space along the front combustion cham-
ber side. Combustion air openings at the rear or side of the
compartment shall comply with the requirements of Chap-
ter?.
Exception: This section shall not apply to replacement
appliances installed in existing compartments and
alcoves where the working space clearances are in accor-
dance with the equipment or appliance manufacturer's
installation instructions.
306.2 Appliances in rooms. Rooms containing appliances
requiring access shall be provided with a door and an unob-
structed passageway measuring not less than 36 inches (914
mm) wide and 80 inches (2032 mm) high.
Exception: Within a dwelling unit, appliances installed in a
compartment, alcove, basement or similar space shall be
accessed by an opening or door and an unobstructed pas-
sageway measuring not less than 24 inches (610 mm) wide
and large enough to allow removal of the largest appliance
in the space, provided that a level service space of not less
than 30 inches (762 mm) deep and the height of the appli-
ance, but not less than 30 inches (762 mm), is present at the
front or service side of the appliance with the door open.
306.3 Appliances in attics. Attics containing appliances
requiring access shall be provided with an opening and unob-
structed passageway large enough to allow removal of the larg-
est appliance. The passageway shall not be less than 30 inches
(762 mm) high and 22 inches (559 mm) wide and not more than
20 feet (6096 mm) in length measured along the center line of
the passageway from the opening to the appliance. The pas-
sageway shall have continuous solid flooring not less than 24
inches (610 mm) wide. A level service space not less than 30
inches (762 mm) deep and 30 inches (762 mm) wide shall be
26
2007 OREGON MECHANICAL SPECIALTY CODE
GENERAL REGULATIONS
present at the front or service side of the apphance. The clear
access opening dimensions shall be a minimum of 20 inches by
30 inches (508 mm by 762 mm), where such dimensions are
large enough to allow removal of the largest appliance.
Exceptions:
1. The passageway and level service space are not
required where the appliance is capable of being ser-
viced and removed through the required opening.
2. Where the passageway is unobstructed and not less
than 6 feet (1 829 mm) high and 22 inches wide for its
entire length, the passageway shall be not greater than
50 feet (15 250 mm) in length.
306.3.1 Electrical requirements. A luminaire controlled
by a switch located at the required passageway opening and
a receptacle outlet shall be provided at or near the appliance
location in accordance with the Electrical Code.
306.4 Appliances under floors. Underfloor spaces containing
appliances requiring access shall be provided with an access
opening and unobstructed passageway large enough to remove
the largest appliance. The passageway shall not be less than 30
inches (762 mm) high and 22 inches (559 mm) wide, nor more
than 20 feet (6096 mm) in length nieasured along the centerline
of the passageway from the opening to the appliance. A level
service space not less than 30 inches (762 mm) deep and 30
inches (762 mm) wide shall be present at the front or service
side of the appliance. If the depth of the passageway or the ser-
vice space exceeds 12 inches (305 mm) below the adjoining
grade, the walls of the passageway shall be lined with concrete
or masonry. Such concrete or masonry shall extend a minimum
of 4 inches (102 mm) above the adjoining grade and shall have
sufficient lateral-bearing capacity to resist collapse. The clear
access opening dimensions shall be a minimum of 22 inches by
30 inches (559 mm by 762 mm), where such dimensions are
large enough to allow removal of the largest appliance.
Exceptions:
1. The passageway is not required where the level ser-
vice space is present when the access is open and the
appliance is capable of being serviced and removed
through the required opening.
2. Where the passageway is unobstructed and not less
than 6 feet high (1929 mm) and 22 inches wide for its
entire length, the passageway shall not be limited in
length.
306.4.1 Electrical requirements. A luminaire controlled
by a switch located at the required passageway opening and
a receptacle outlet shall be provided at or near the appliance
location in accordance with the Electrical Code.
306.5 Equipment and appliances on roofs or elevated struc-
tures. Where equipment and appliances requiring access are
installed on roofs or elevated structures at a height exceeding
16 feet (4877 mm), such access shall be provided by a perma-
nent approved means of access, the extent of which shall be
from grade or floor level to the equipment and appliances' level
service space. Such access shall not require climbing over
obstructions greater than 30 inches (762 mm) high or walking
on roofs having a slope greater than 4 units vertical in 12 units
horizontal (3 3 -percent slope).
Permanent ladders installed to provide the required access
shall comply with the following minimum design criteria:
1 . The side railing shall extend above the parapet or roof
edge not less than 30 inches (762 mm).
2. Ladders shall have rung spacing not to exceed 14 inches
(356 mm) on center.
3. Ladders shall have a toe spacing not less than 6 inches
(152 mm) deep.
4; There shall be a minimum of 18 inches (457 mm)
between rails.
5. Rungs shall have a minimum 0.75-inch (19 mm) diame-
ter and be capable of withstanding a 300-pound (136.1
kg) load.
6. Ladders over 30 feet (9144 mm) in height shall be pro-
vided with offset sections and landings capable of with-
standing 100 pounds (488.2 kg/m^) per square foot.
7. Ladders shall be protected against corrosion by
approved means.
Catwalks installed to provide the required access shall be not
less than 24 inches (610 mm) wide and shall have railings as
required for service platforms.
Exception: This section shall not apply to the replacement,
repair or maintenance of an existing appliance or piece of
equipment lawfully in existence at the time of the adoption
of this code.
306.6 Sloped roofs. Where appliances, equipment, fans or
other components that require service are installed on a roof
having a slope of three units vertical in 12 units horizontal
(25 -percent slope) or greater and having an edge more than 30
inches (762 mm) above grade at such edge, a level platform
shall be provided on each side of the appliance to which access
is required for service, repair or maintenance. The platform
shall be not less than 30 inches (762 mm) in any dimension and
shall be provided with guards. The guards shall extend not less
than 42 inches (1067 mm) above the platform, shall be con-
structed so as to prevent the passage of a 21-inch-diameter (533
mm) sphere and shall comply with the loading requirements
for guards specified in the Building Code.
Exception: This section shall not apply to the replacement,
repair or rnaintenance of an existing appliance or piece of
equipment lawfully in existence at the time of the adoption
of this code.
SECTION 307
CONDENSATE DISPOSAL
307.1 Fuel-burning appliances. Liquid combustion by-prod-
ucts of condensing appliances shall be collected and dis-
charged to an approved plumbing fixture or disposal area in
accordance with the manufacturer's installation instructions.
Condensate piping shall be of approved corrosion-resistant
material and shall not be smaller than the drain connection on
the appliance. Such piping shall maintain a minimum horizon-
tal slope in the direction of discharge of not less than
2007 OREGON MECHANICAL SPECIALTY CODE
27
GENERAL REGULATIONS
one-eighth unit vertical in 12 units horizontal (1 -percent
slope).
307.2 Evaporators and cooling coils. Condensate drain sys-
tems shall be provided for equipment and appliances contain-
ing evaporators or cooling coils. Condensate drain systems
shall be designed, constructed and installed in accordance with
Sections 307.2.1 through 307.2.4.
3§7.2ol Condensate disposal. Condensate from all cooling
coils and evaporators shall be conveyed from the drain pan
outlet to an approved place of disposal as follows:
1. Units larger than 6 tons (21.1 kW) nominal capacity
shall dischai'ge to a sanitary sewer drain or storm
sewer drain. Where discharging to a sanitary sewer,
such drains shall be indirectly connected in accor-
dance with the Plumbing Code.
2. Units 6 tons (21.1 kW) and smaller nominal capacity
shall discharge in accordance with Item 1 , or shall dis-
charge to a gutter, roof drain or other approved loca-
tion.
3. Condensate drains from rooftop units shall discharge
in accordance with Item 1 or 2, or shall discharge onto
rooftops where the condensate does not discharge
into a street, alley or other areas so as to cause a nui-
sance.
3®7.2.2 Drain pipe materials and sizes. Components of
the condensate disposal system shall be cast iron, galva-
nized steel, copper, cross-linked polyethylene,
polybutylene, polyethylene, ABS, CPVC or PVC pipe or
tubing. All components shall be selected for the pressure
and temperature rating of the installation. Condensate waste
and drain line size shall be not less than V4-inch (19 mm)
internal diameter and shall not decrease in size from the
drain pan connection to the place of condensate disposal.
Where the drain pipes from more than one unit are
manifolded together for condensate drainage, the pipe or
tubing shall be sized in accordance with an approved
method. All horizontal sections of drain piping shall be
installed in uniform alignment at a uniform slope.
307.2.3 Auxiliary and secondary drain systems. In addi-
tion to the requirements of Section 307.2.1, a secondary
drain or auxiliary drain pan shall be required for each cool-
ing or evaporator coil or fuel-fired appliance that produces
condensate, where damage to any building components will
occur as a result of overflow from the equipment drain pan
or stoppage in the condensate drain piping. One of the fol-
lowing methods shall be used:
1 . An auxiliary drain pan with a separate drain shall be
provided under the coils on which condensation will
occur. The auxiliary pan drain shall discharge to a
conspicuous point of disposal to alert occupants in the
event of a stoppage of the primary drain. The pan shall
have a minimum depth of 1.5 inches (38 mm), shall
not be less than 3 inches (76 mm) larger than the unit
or the coil dimensions in width and length and shall be
constructed of corrosion-resistant material. Metallic
pans shall have a minimum thickness of not less than
0.0276-inch (0.7 mm) galvanized sheet metal. Non-
metaUic pans shall have a minimum thickness of not
less than 0.0625 inch (1.6 mm).
2. A separate overflow drain line shall be connected to
the drain pan provided with the equipment. Such
overflow drain shall discharge to a conspicuous point
of disposal to alert occupants in the event of a stop-
page of the primary drain. The overflow drain line
shall connect to the drain pan at a higher level than the
primary drain connection.
3. An auxiliary drain pan without a separate drain line
shall be provided under the coils on which condensate
will occur. Such pan shall be equipped with a
water-level detection device conforming to UL 508
that will shut off the equipment served prior to over-
flow of the pan. The auxiliary drain pan shall be con-
structed in accordance with Item 1 of this section.
4. A water level detection device conforming to UL 508
shall be provided that will shut off the equipment
served in the event that the primary drain is blocked.
The device shall be installed in the primary drain line,
the overflow drain line, or in the equipment-supplied
drain pan, located at a point higher than the primary
drain line connection and below the overflow rim of
such pan.
Exception: Fuel-fired appliances that automatically
shut down operation in the event of a stoppage in the
condensate drainage system.
307.2.3.1 Water-level monitoring devices. On
down-flow units and all other coils that do not have a sec-
ondary drain and do not have a means to install an auxil-
iary drain pan, a water-level monitoring device shall be
installed inside the primary drain pan. This device shall
shut off the equipment served in the event that the pri-
mary drain becomes restricted. Externally installed
devices and devices installed in the drain hne shall not be
permitted.
307.2.4 Traps. Condensate drains shall be trapped as
required by the equipment or appliance manufacturer.
SECTION 308
CLEARANCE REDUCTION
308.1 Scope. This section shall govern the reduction in
required clearances to combustible materials and combustible
assemblies for chimneys, vents, kitchen exhaust equipment,
mechanical appliances, and mechanical devices and equip-
ment.
308.2 Listed appliances and equipment. The reduction of the
required clearances to combustibles for listed and labeled
appliances and equipment shall be in accordance with the
requirements of this section except that such clearances shall
not be reduced where reduction is specifically prohibited by the
terms of the appliance or equipment listing.
Exception: Unlisted appliances and equipment, when
approved by the building official, shall be in accordance
with an approved nationally recognized standard.
28
2007 OREGON MECHANICAL SPECIALTY CODE
GENERAL REGULATIONS
308.3 Protective assembly construction and installation.
Reduced clearance protective assemblies, including structural
and support elements, shall be constructed of noncombustible
materials. Spacers utilized to maintain an airspace between the
protective assembly and the protected material or assembly
shall be noncombustible. Where a space between the protective
assembly and protected combustible material or assembly is
specified, the same space shall be provided around the edges of
the protective assembly and the spacers shall be placed so as to
allow air circulation by convection in such space. Protective
assemblies shall not be placed less than 1 inch (25 mm) from
the mechanical appliances, devices or equipment, regardless of
the allowable reduced clearance.
308.4 Allowable reduction. The reduction of required clear-
ances to combustible assemblies or cornbustible materials shall
be based on the utilization of a reduced clearance protective
assembly in accordance with Section 308.5 or 308.6.
308.5 Labeled assemblies. The allowable clearance reduction
shall be based on an approved reduced clearance protective
assembly that has been tested and bears the label of an
approved agency.
308.6 Reduction table. The allowable clearance reduction
shall be based on one of the methods specified in Table 308.6.
Where required clearances are not listed in Table 308.6, the
reduced clearances shall be determined by linear interpolation
between the distances listed in the table. Reduced clearances
shall not be derived by extrapolation below the range of the
table.
308.7 Solid fuel-burning appliances. The clearance reduction
methods specified in Table 308.6 shall not be utilized to reduce
the clearance required for solid fuel-burning appliances that
are labeled for installation with clearances of 12 inches (305
mm) or less. Where appliances are labeled for installation with
clearances of greater than 12 inches (305 mm), the clearance
reduction methods of Table 308.6 shall not reduce the clear-
ance to less than 12 inches (305 mm).
308.8 Masonry chimneys. The clearance reduction methods
specified in Table 308.6 shall not be utilized to reduce the clear-
TABLE 308.6
CLEARANCE REDUCTION METHODS
TYPE OF PROTECTIVE ASSEMBLY^
REDUCED CLEARANCE WITH PROTECTION (inches^
Horizontat combusti ble assemblies
located above the heat source
Horizontal combustible assemblies
located beneath the heat source and all
vertical combustible assemblies
Required clearance to combustibles
without protection (inches)^
Required clearance to combustibles
without protection (inches)^
36
18
9
6
36
18
9
6
Galvanized sheet metal, minimum nominal thickness of 0.024
inch (No. 24 Gage), mounted on 1-inch glass fiber or mineral
wool batt reinforced with wire on the back, 1 inch off the
combustible assembly
18
9
5
3
12
6
3
3
Galvanized sheet metal, minimum nominal thickness of 0.024
inch (No. 24 Gage), spaced 1 inch off the combustible
assembly
18
9
5
3
12
6
3
2
Two layers of galvanized sheet metal, minimum nominal
thickness of 0.024 inch (No. 24 Gage), having a 1-inch
airspace between layers, spaced 1 inch off the combustible
assembly
18
9
5
3
12
6
3
3
Two layers of galvanized sheet metal, minimum nominal
thickness of 0.024 inch (No. 24 Gage), having 1 inch of
fiberglass insulation between layers, spaced 1 inch off the
combustible assembly
18
9
5
3
12
6
3
3
0.5-inch inorganic insulating board, over 1 inch of fiberglass or
mineral wool batt, against the combustible assembly
24
12
6
4
18
9
5
3
3.5-inch brick wall, spaced 1 inch off the combustible wall
—
—
—
—
12
6
6
6
3.5-inch brick wall, against the combustible wall
24
12
6
5
Prefabricated brick 1 Vg-inch thick spaced out 1 inch and
ventilated.
30
15
9
3
18
9
6
3
For SI: 1 inch = 25.4 mm, °C = [(°F)-32]/1.8, 1 pound per cubic foot = 16.02 kgAn^ 1.0 Btu ■ in/ft^ • h . °F = 0.144 W/m^ • K.
a. Mineral wool and glass fiber batts (blanket or board) shall have a minimum density of 8 pounds per cubic foot and a minimum melting point of 1 ,500°F. Insulation
material utilized as part of a clearance reduction system shall have a thermal conductivity of 1.0 Btu • in./(ft^ -h • °F) or less. Insulation board shall be formed of
noncombustible material.
2007 OREGON MECHANICAL SPECIALTY CODE
29
GENERAL REGULATIONS
ances required for masonry chimneys as specified in Chapter 8
and the Building Code.
308.9 ClhimEey coneector pass-tlhroiuiglhis. The clearance
reduction methods specified in Table 308.6 shall not be utilized
to reduce the clearances required for chimney connector
pass-throughs as specified in Section 803.10.4.
308.1(01 Masonry lElreplaces. The clearance reduction methods
specified in Table 308.6 shall not be utilized to reduce the clear-
ances required for masonry fireplaces as specified in Chapter 8
and the Building Code.
308.11 Kitelheini exhaiiist dmcits. The clearance reduction meth-
ods specified in Table 308.6 shall not be utiHzed to reduce the
minimum clearances required by Section 506.3.10 for kitchen
exhaust ducts enclosed in a shaft.
>
30 2007 OREGON IVJECHANICAL SPECIALTY CODE
CHAPTER 4
VENTILATION
SECTION 401
GENERAL
401.1 Scope. This chapter shall govern the ventilation of
spaces within a building intended to be occupied. This chapter
does not govern the requirements for smoke control systems.
The principles specified in ASHRAE Standard 62-2001 may
be used as an alternate to this chapter to demonstrate compli-
ance with required ventilation air for occupants.
401.2 Veetilatiom required. Every occupied space shall be
I I ventilated by natural means in accordance with Chapter 12 of
^ the Building Code or by mechanical means in accordance with
Section 403.
Note: Heating and air conditioning controls shall conform to Chap-
ter 13 of the Oregon Structural Specialty Code.
401.3 When required. Ventilation shall be provided during the
periods that the room or space is occupied.
401.4 Opening location. Outdoor air exhaust and intake open-
ings shall be located a minimum of 10 feet (3048 mm) from lot
lines or buildings on the same lot. Where openings front on a
street or public way, the distance shall be measured to the cen-
terline of the street or public way.
Exceptions:
1. Group R-3.
2. Exhaust outlets for environmental air exhaust open-
ings shall be located not less than 3 feet (914 mm)
from property lines and not less than 3 feet (914 mm)
from openings into the building.
401.4.1 Intake openings. Mechanical and gravity outdoor
air intake openings shall be located a minimum of 10 feet
(3048 mm) horizontally from any hazardous or noxious
contaminant source, such as vents, chimneys, plumbing
vents, streets, alleys, parking lots, gas meters and loading
docks, except as otherwise specified in this code. Where a
source of contaminant is located within 10 feet (3048 mm)
horizontally of an intake opening, such opening shall be
located a minimum of 2 feet (610 mm) below the contami-
nant source.
The exhaust from a bathroom or kitchen in a residential
dwelling shall not be considered to be a hazardous or nox-
ious contaminant.
401.4.2 Exhaust openings. Outdoor exhaust openings shall
be located so as not to create a nuisance. Exhaust air shall
not be directed onto walkways.
401.4.3 Flood hazard. For structures located in flood haz-
ard areas, outdoor exhaust openings shall be at or above the
design flood elevation.
401.5 Outdoor opening protection. Air exhaust and intake
openings that terminate outdoors shall be protected with corro-
sion-resistant screens, louvers or grilles. Openings in louvers,
grilles and screens shall be sized in accordance with Table
401.5, and shall be protected against local weather conditions.
Outdoor air exhaust and intake openings located in exterior
walls shall meet the provisions for exterior wall opening
protectives in accordance with the Building Code.
TABLE 401 .5
OPENING SIZES IN LOUVERS, GRILLES AND
SCREENS PROTECTING OUTDOOR EXHAUST
AND AIR INTAKE OPENINGS
OUTDOOR OPENING TYPE
MINIMUM AND MAXIMUM OPENING
SIZES IN LOUVERS, GRILLES AND
SCREENS MEASURED IN ANY
DIRECTION
Exhaust openings
Not < '/4 inch and not > V2 inch
Intake openings in residential
occupancies
Not < V4 inch and not > V2 inch
Intake openings in other than
residential occupancies
> V4 inch and not > 1 inch
For SI: 1 inch = 25.4 mm.
401.6 Contaminant sources. Stationary local sources produc-
ing air-borne particulates, heat, odors, fumes, spray, vapors,
smoke or gases in such quantities as to be irritating or injurious
to health shall be provided with an exhaust system in accor-
dance with Chapter 5 or a means of collection and removal of
the contaminants. Such exhaust shall discharge directly to an
approved location at the exterior of the building.
SECTION 402
NATURAL VENTILATION
(See Chapter 12 of the Oregon Structural Specialty Code)
SECTION 403
MECHANICAL VENTILATION
403.1 Ventilation system. Mechanical ventilation shall be pro-
vided by a method of supply air and return or exhaust air. The
amoiint of supply air shall be approximately equal to the
amount of return and exhaust air. The system shall not be pro-
hibited from producing negative or positive pressure. The sys-
tem to convey ventilation air shall be designed and installed in
accordance with Chapter 6.
Ventilation supply systems shall be designed to deliver the
required rate of supply air to the occupied zone within an occu-
pied space. The occupied zone shall have boundaries measured
at 3 inches (76 mm) and 72 inches (1829 mm) above the floor
and 24 inches (610 mm) from the enclosing walls.
2007 OREGON WIECHANICAL SPECIALTY CODE
31
VENTILATION
403.2 Outdoor air required. The minimum ventilation rate of
outdoor air shall be determined in accordance with Section
403.3.
Exception!: Where the registered design professional dem-
onstrates that an engineered ventilation system design will
prevent the maximum concentration of contaminants from
exceeding that obtainable by the rate of outdoor air ventila-
tion determined in accordance with Section 403.3, the mini-
mum required rate of outdoor air shall be reduced in
accordance with such engineered system design.
L2.1 Recirculation of air. The air required by Section
403 . 3 shall not be recirculated. Air in excess of that required by
Section 403.3 shaU not be prohibited from being recirculated
as a component of supply air to building spaces, except that:
1. Ventilation air shall not be recirculated from one
dwelling to another or to dissimilar occupancies.
2. Supply air to a swimming pool and associated deck
areas shall not be recirculated unless such air is dehu-
midified to maintain the relative humidity of the area
at 60 percent or less. Air from this area shall not be
recirculated to other spaces where 10 percent or more
of the resulting supply airstream consists of air
recirculated from these spaces.
3. Where mechanical exhaust is required by Note b in
Table 403.3, recirculation of air from such spaces
shall be prohibited. All air supplied to such spaces
shall be exhausted, including any air in excess of that
required by Table 403.3.
4. Where mechanical exhaust is required by Note h in
Table 403.3, mechanical exhaust is required and
recirculation is prohibited where 10 percent or more
of the resulting supply airstream consists of air
recirculated from these spaces.
> 403.2.2 Transfer air. Air transferred from occupied spaces is
not prohibited from serving as makeup air for required
exhaust systems in such spaces as kitchens, baths, toilet
rooms, elevators and smoking lounges. The amount of trans-
fer air and exhaust air shall be sufficient to provide the flow
rates as specified in Sections 403.3 and 403.3. 1 . The required
outdoor air rates specified in Table 403.3 shall be introduced
directly into such spaces or into the occupied spaces from
which air is transferred or a combination of both.
Exceptions:
1. Where recirculation from such spaces is prohib-
ited by Table 403.3.
2. Air transferred from spaces served by other fan
systems shall not be used if those systems are
required to meet either Section 401.6 of this code
or Section 13 17.2.2 or 1 3 1 8.3 of the Oregon Struc-
tural Specialty Code.
3. Where the ventilation schedule of HVAC system
supplying transfer air is not similar to the exhaust
system operating schedule.
403.3 Ventilation rate. Ventilation systems shall be designed to
have the capacity to supply the minimum outdoor airflow rate
determined in accordance with Table 403.3 based on the occu-
pancy of the space and the occupant load or other parameter as
stated therein. The occupant load utilized for design of the venti-
lation system shall be based on expected average occupant load
provided the average occupant load is not less than one-half the
number determined from the estimated maximum occupant load
rate indicated in Table 403.3. The anticipated ventilation occu-
pancy load and occupancy ventilation design methods shall be
documented on plans and specifications. The ventilation system
shall be designed to supply the required rate of ventilation air
continuously during the period the building is occupied, except
as otherwise stated in other provisions of the code.
Exception: The occupant load is not required to be deter-
mined, based on the estimated maximum occupant load rate
indicated in Table 403.3 where approved statistical data docu-
ment the accuracy of an alternate anticipated occupant density.
403.3.1 System operation. The minimum flow rate of out-
door air that the ventilation system must be capable of sup-
plying during its operation shall be permitted to be based on
the rate per person indicated in Table 403.3 and the actual
number of occupants present.
403.3.2 Common ventilation system. Where spaces hav-
ing different ventilation rate requirements are served by a
common ventilation system, the ratio of outdoor air to total
supply air for the system shall be determined based on the
space having the largest outdoor air requirement or shall be
determined in accordance with the following formula:
Y =
X
(1+X-Z)
(Equation 4-1)
where
Y= Yot^st - Corrected fraction of outdoor air in system
supply.
X = Yon^st - Uncorrected fraction of outdoor air in sys-
tem supply.
Z = V,,^ /\/ ^ = Fraction of outdoor air in critical space. The
critical space is that space with the greatest
required fraction of outdoor air in the supply
to this space.
V^, = Corrected total outdoor airflow rate.
y,j = Total supply flow rate, i.e., the sum of all supply for
all branches of the system.
Vg„ = Simiofoutdoor airflow rates for all branches on system.
Voc = Outdoor airflow rate required in critical spaces.
Vjc = Supply flow rate in critical space.
403.3.3 Variable air volume system control. Variable air
volume air distribution systems, other than those designed
to supply only 100-percent outdoor air, shall be provided
with controls to regulate the flow of outdoor air. Such con-
trol system shall be designed to maintain the flow of outdoor
air at a rate of not less than that required by Section 403 over
the entire range of supply air operating rates.
403.3.4 Balancing. Ventilation systems shall be balanced
by an approved method. Such balancing shall verify that the
ventilation system is capable of supplying the airflow rates
required by Section 403.
32
2007 OREGON MECHANICAL SPECIALTY CODE
VENTILATION
TABLE 403.3
REQUIRED OUTDOOR VENTILATION AIR
TABLE 403.3— continued
REQUIRED OUTDOOR VENTILATION AIR
ESTIMATED
MAXIMUM
OUTDOOR AIR
OCCUPANT LOAD,
[Cubic feet per
PERSONS PER
minute (cfm) per
OCCUPANCY
1,000 SQUARE
person] UNLESS
CLASSIFICATION
FEEr
NOTED^
Correctional facilities
Cells
widiout plumbing fixtures
20
20
with plumbing fixtures^' ^
20
20
Dining halls
100
15
Guard stations
40
15
Dry cleaners, laundries
Coin-operated dry cleaner
20
15
Coin-operated laundries
20
15
Commercial dry cleaner
30
30
Commercial laundry
10
25
Storage, pick up
30
35
Education
Auditoriums
150
15
Classrooms
50
15
Corridors
—
O.lOcfm/ft^
Laboratories
30
20
Libraries
20
15
Locker rooms'^
—
0.50 cfm/ft^
Music rooms
50
15
Smoking lounges'''^
70
60
Training shops
30
20
Food and beverage service
Bars, cocktail lounges
100
30
Cafeteria, fast food
100
20
Dining rooms
70
20
Kitchens (cooking)^'^
20
15
Hospitals, nursing and
convalescent homes
Autopsy rooms''
—
0.50cfm/ft2
Medical procedure rooms
20
15
Operating rooms
20
30
Patient rooms
10
25
Physical therapy
20
15
Recovery and ICU
20
15
Hotels, motels, resorts and
dormitories
Assembly rooms
120
15
Bathrooms^' ^
—
35
Bedrooms
—
30 cfm per room
Conference rooms
50
20
Dormitory sleeping areas
20
15
Gambling casinos
120
30
Living rooms
—
30 cfm per room
Lobbies
30
15
Offices
Conference rooms
50
20
Office spaces
7
20
Reception areas
60
15
Telecommunication centers
and data entry
60
20
(continued)
ESTIMATED
MAXIMUM
OUTDOOR AIR
OCCUPANT
(Cubic feet per
LOAD, PERSONS
minute (cfm)
OCCUPANCY
PER 1,000
per person)
CLASSIFICATION
SQUARE FEEr
UNLESS NOTED=
Private dwellings, single and
multiple
Garages, common for
multiple units''
—
1.5cfm/ft2
Garages, separate for
each dwelling
—
100 cfm per car
Kitchens^
100 cfm
intermittent or 25
cfm continuous
Living areas'^
, Based upon
number of
bedrooms, first
0.35 air changes
perhour^or 15 cfm
bedroom: 2; each
per person,
whichever is
additional
bedroom: 1
greater
Toilet rooms and
—
Mechanical
bathrooms^' ''
exhaust capacity of
50 cfm intermittent
or 20 cfm
continuous
Public spaces
Corridors and utilities
—
0.05 cfm/ft^
Elevator car^
—
l.OOcfm/ft^
Locker rooms'*
0.5 cfm/ft^
Shower rooms
50 cfm
(per shower head)^'*'
intermittent or 20
cfm continuous
Smoking lounges'''^
70
60
Toilet roomsS'''
75 cfm per water
closet or urinal
Retail stores, sales floors and
showroom floors
Basement and street
—
0.30 cfm/ft^
Dressing rooms
—
0.20 cfm/ft^
Malls and arcades
—
0.20 cfm/ft2
Shipping and receiving
—
0.15cfm/ft2
Smoking lounges''
70
60
Storage rooms
—
0.15cfm/ft2
Upper floors
—
0.20 cfm/ft^
Warehouses
—
0.05 cfm/ft2
Specialty shops
Automotive motor-
fuel-dispensing stations
—
1.5 cfm/ft^
Barber
25
15
Beauty
25
25
Clothiers, furniture
—
0.30 cfm/ft^
Embalming room''
2.0 cfm/ft^
Florists
8
15
Hardware, drugs, fabrics
8
15
(continued)
2007 OREGON MECHANICAL SPECIALTY CODE
33
VENTILATJON
TABLE 403.3— continued
REQUIRED OUTDOOR VENTILATION MR
ESTIMATED
MAXIMUM
OUTDOOR AIR
OCCUPANT
(Cubic feet per
LOAD, PERSONS
minute (cfm)
OCCUPANCY
PER 1,000
per person)
CLASSIFICATION
SQUARE FEEr
UNLESS NOTED^
Specialty shops — continued
50 cfm
intermittent or 20
cfm continuous
Nail salon''' '
per station
Pet shops
—
l.OOcfm/ft^
Reducing salons
20
15
Supermarkets
8
15
Sports and amusement
Ballrooms and discos
100
25
Bowling alleys (seating areas)
70
25
Game rooms
70
25
Ice arenas
—
0.50 cfm/ft^
Playing floors (gymnasiums)
30
20
Spectator areas
150
15
Swimming pools (pool and deck
area)
—
0.50 cfm/ft^
Storage
Repair garages, enclosed
parking garages'*
—
1.5cfm/ft2
Warehouses
—
0.05 cfm/ft^
Theaters
Auditoriums
150
15
Lobbies
150
20
Stages, studios
70
15
Ticket booths
60
20
Transportation
Platforms
100
15
Vehicles
150
15
Waiting rooms
100
15
Workrooms
Bank vaults
5
15
Darkrooms
—
0.50 cfm/ft^
Duplicating, printing
—
0.50 cfm/ft^
Meat processing'^
10
15
Pharmacy
20
15
Photo studios
10
15
For SI: 1 cubic foot per minute = 0.00047 19 m^/s, 1 ton = 908 kg,
1 cubic foot per minute per square foot = 0.00508 m^/(s • m^),
°C = [(T) -32]/l .8, 1 square foot = 0.0929 m^.
a. Based upon net floor area.
b. Mechanical exhaust required and the recirculation of air from such spaces as
permittedby Section 403.2.1 is prohibited(see Section 403.2.1, Items 1 and3).
c. Spaces unheated or maintained below 50°F are not covered by these require-
ments unless the occupancy is continuous.
d. Ventilation systems in enclosed parking garages shall comply with Section
404.
e. Where the ventilation rate is expressed in cfm/ft^, such rate is based upon
cubic feet per minute per square foot of the floor area being ventilated.
f. The sum of the outdoor and transfer air from adjacent spaces shall be suffi-
cient to provide an exhaust rate of not less than 1.5 cfm/ft^.
g. Transfer air permitted in accordance with Section 403.2.2.
h. Mechanical exhaust is required and recirculation is prohibited except that
recirculation shall be permitted where the resulting supply airstream con-
sists of not more than 10 percent air recirculated from these spaces (see Sec-
tion 403.2.1, Items 2 and 4).
i. The required exhaust system shall capture the contaminants and odors at
their source.
SECTBOM 404
ENCLOSED PARKING GARAGES
404.1 Enclosed parking garages. Mechanical ventilation sys-
tems for enclosed parking garages shall be permitted to operate
intermittently where the system is arranged to operate automat-
ically upon detection of vehicle operation or the presence of
occupants by approved automatic detection devices.
404.1.1 Enclosed parking garage ventiilatiom controls.
See Section 1317.2.3 of the Oregon Structural Specialty
Code.
404.2 Minimum ventilation. Automatic operation of the sys-
tem shall not reduce the ventilation rate below 0.05 cfm per
square foot (0.00025 mVs • m^) of the floor area and the system
shall be capable of producing a ventilation rate of 1.5 cfm per
square foot (0.0076m^/s • m^) of floor area.
404.3 Occupied spaces accessory to public garages. Con-
necting offices, waiting rooms, ticket booths and similar uses
that are accessory to a public garage shall be maintained at a
positive pressure and shall be provided with ventilation in
accordance with Section 403.3.
SECTION 405
SYSTEMS CONTROL
405.1 General. Mechanical ventilation systems shall be pro-
vided with manual or automatic controls that will operate such
systems whenever the spaces are occupied. Air-conditioning
systems that supply required ventilation air shall be provided
with controls designed to automatically maintain the required
outdoor air supply rate during occupancy.
405.1.1 Ventilation controls for high occupancy areas.
See Section 1317.2.2 of the Oregon Structural Specialty
Code.
SECTION 406
VENTILATION OF UNINHABITED SPACES
406.1 General. Uninhabited spaces, such as crawl spaces and
attics, shall be provided with natural ventilation openings as
required by the Building Code or shall be provided with a
mechanical exhaust and supply air system. The mechanical
exhaust rate shall be not less than 0.02 cfm. per square foot
(0.00001 mVs • m^) of horizontal area and shall be automati-
cally controlled to operate when the relative humidity in the
space served exceeds 60 percent.
34
2007 OREGON MECHANICAL SPECIALTY CODE
CHAPTER 5
EXHAUST SYSTEMS
SECTION 501
GENERAL
501.1 Scope. This chapter shall govern the design, construc-
tion and installation of mechanical exhaust systems, including
dust, stock and refuse conveyor systems, exhaust systems serv-
ing commercial cooking appliances and energy recovery venti-
lation systems.
501.2 Exhaust discharge. The air removed by every mechani-
cal exhaust system shall be discharged outdoors at a point
where it will not cause a nuisance and not less than the dis-
tances specified in Section 501 .2. 1 . The air shall be discharged
to a location from which it cannot again be readily drawn in by
a ventilating system. Air shall not be exhausted into an attic or
crawl space.
Exceptions:
1 . Whole-house ventilation-type attic fans shall be per-
mitted to discharge into the attic space of dwelMng
units having private attics.
2. Commercial cooking recirculating systems.
501.2.1 Location of exhaust outlets. The termination point
of exhaust outlets and ducts discharging to the outdoors
shall be located with the following minimum distances:
1 . For ducts conveying explosive or flammable vapors,
fumes or dusts: 30 feet (9144 mm) from property
lines; 10 feet (3048 mm) from operable openings into
buildings; 6 feet (1829 mm) from exterior walls and
roofs; 30 feet (9144 mm) from combustible walls and
operable openings into buildings which are in the
direction of the exhaust discharge; 10 feet (3048 mm)
above adjoining grade.
2. For other product-conveying outlets: 10 feet (3048
mm) from the property lines; 3 feet (914 mm) from
exterior walls and roofs; 10 feet (3048 mm) from
operable openings into buildings; 10 feet (3048 mm)
above adjoining grade.
3. For environmental air duct exhaust: 3 feet (914 mm)
from property lines; 3 feet (914 mm) from operable
openings into buildings for all occupancies other than
Group U, and 10 feet (3048 mm) from mechanical air
intakes.
4. For specific systems: For clothes dryer exhaust, see
Section 504.4; for kitchen hoods, see Section 506.3;
for dust, stock and conveying systems, see Section
511.2; and for subslab soil exhaust systems, see Sec-
tion 512.4.
501.3 Pressure equalization. Mechanical exhaust systems
shall be sized to remove the quantity of air required by this
chapter to be exhausted. The system shall operate when air is
required to be exhausted. Where mechanical exhaust is
required in a room or space in other than occupancies in R-3,
such space shall be maintained with a neutral or negative pres-
sure. If a greater quantity of air is supplied by a mechanical
ventilating supply system than is removed by a mechanical
exhaust for a room, adequate means shall be provided for the
natural or mechanical exhaust of the excess air supplied. If only
a mechanical exhaust system is installed for a room or if a
greater quantity of air is removed by a mechanical exhaust sys-
tem than is supplied by a mechanical ventilating supply system
for a room, adequate make-up air consisting of supply air,
transfer air or outdoor air shall be provided to satisfy the defi-
ciency. The calculated building infiltration rate shall not be uti-
lized to satisfy the requirements of this section.
501.4 Ducts. Where exhaust duct construction is not specified
in this chapter, such construction shall comply with Chapter 6.
SECTION 502
REQUIRED SYSTEMS
502.1 General. An exhaust system shall be provided, main-
tained and operated as specifically required by this section and
for all occupied areas where machines, vats, tanks, furnaces,
forges, salamanders and other appliances, equipment and pro-
cesses in such areas produce or throw off dust or particles suffi-
ciently light to float in the air, or which emit heat, odors, fumes,
spray, gas or smoke, in such quantities so as to be irritating or
injurious to health or safety.
502.1.1 Exhaust location. The inlet to an exhaust system
shall be located in the area of heaviest concentration of con-
taminants.
502.1.2 Fuel-dispensing areas. The bottom of an air inlet
or exhaust opening in fuel-dispensing areas shall be located
not more than 18 inches (457 mm) above the floor.
502.1.3 Equipment, appliance and service rooms. Equip-
ment, appliance and system service rooms that house
sources of odors, fumes, noxious gases, smoke, steam, dust,
spray or other contaminants shall be designed and con-
structed so as to prevent spreading of such contaminants to
other occupied parts of the building.
502.1.4 Hazardous exhaust. The mechanical exhaust of
high concentrations of dust or hazardous vapors shall con-
form to the requirements of Section 510.
502.2 Aircraft fueling and defueling. Compartments housing
piping, pumps, air eliminators, water separators, hose reels and
similar equipment used in aircraft fueling and defueling opera-
tions shall be adequately ventilated at floor level or within the
floor itself
502.3 Battery-charging areas for powered industrial trucks
and equipment. Ventilation shall be provided in an approved
manner in battery-charging areas for powered industrial trucks
and equipment to prevent a dangerous accumulation of flam-
mable gases.
2007 OREGON MECHANICAL SPECIALTY CODE
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EXHAUST SYSTER/iS
502.4 Statiomary storage battery systems. Stationary storage
battery systems, as regulated by Section 608 of the Fire Code,
shall be provided with ventilation in accordance with this chap-
ter and Section 502.4.1 or 502.4.2.
I Exceptiom; Lithium-ion batteries shall not require ventilation.
I 502.4.1 Hydrogeo limit io rooms. For flooded lead acid,
I flooded nickel cadmium and VRLA batteries, the ventila-
tion system shall be designed to limit the maximum concen-
tration of hydrogen to 1 .0 percent of the total volume of the
room.
502.4,2 Ventilatioo rate im rooms. Continuous ventilation
shall be provided at a rate of not less than 1 cubic foot per
minute per square foot (cfm/ft^) [0.00508 mV(s • m^)] of
floor area of the room.
>ll
i-regiilated lead-acid batteries in cabinets.
Valve-regulated lead-acid (VRLA) batteries installed in cabi-
nets, as regulated by Section 608.6.2 of the Fire Code, shall be
provided with ventilation in accordance with Section 502.5.1
or 502.5.2.
502.5.1 Hydrogen limit in cabinets. The cabinet ventila-
tion system shall be designed to limit the maximum concen-
tration of hydrogen to 1 .0 percent of the total volume of the
cabinet during the worst-case event of simultaneous boost
charging of all batteries in the cabinet.
502.5.2 Ventilation rate in cabinets. Continuous cabinet
ventilation shall be provided at a rate of not less than 1 cubic
foot per minute per square foot (cfm/ft.^) [0.00508 mV(s •
m^)] of the floor area covered by the cabinet. The room in
which the cabinet is installed shall also be ventilated as
required by Section 502.4.1 or 502.4.2.
502.6 Dry cleaning plants. Ventilation in dry cleaning plants
shall be in accordance with Sections 502.6.1 and 502.6.2.
502.6.1 Type II systems. Type II dry cleaning systems shall
be provided with a mechanical ventilation system that is
designed to exhaust 1 cubic foot of air per minute for each
square foot of floor area (1 cfm/ft-) [0.00508 mV(s • m^)] in
dry cleaning rooms and in drying rooms. The ventilation
system shall operate automatically when the dry cleaning
equipment is in operation and shall have manual controls at
an approved location.
je IV and V systems. Type IV and V dry clean-
ing systems shall be provided with an automatically acti-
vated exhaust ventilation system to maintain a minimum of
100 feet per minute (0.5 m/s) air velocity through the load-
ing door when the door is opened.
Exception: Dry cleaning units are not required to be pro-
vided with exhaust ventilation where an exhaust hood is
installed immediately outside of and above the loading
door which operates at an airflow rate as follows:
Q = 1 00 X A^o (Equation 5-1)
where:
Q = Flow rate exhausted through the hood, cubic feet
per minute.
^LD= Area of the loading door, square feet.
502.6.3 Spotting and pretreating. Scrubbing tubs, scour-
ing, brushing or spotting operations shall be located such
that solvent vapors are captured and exhausted by the venti-
lating system.
502.7 Application of flammable finishes. Mechanical
exhaust as required by this section shall be provided for opera-
tions involving the application of flammable finishes.
502.7.1 Limited spraying spaces. Positive mechanical
ventilation which provides a minimum of six complete air
changes per hour shall be installed in limited spraying
spaces. Such system shall meet the requirements of the Fire
Code for handling flammable vapors. Explosion venting is
not required.
502.7.2 Flammable vapor areas. Mechanical ventilation
of flammable vapor areas shall be provided in accordance
with Sections 502.7.2.1 through 502.7.2.6.
502.7.2.1 Operation. Mechanical ventilation shall be
kept in operation at all times while spraying operations
are being conducted and for a sufficient time thereafter to
allow vapors from drying coated articles and finishing
material residue to be exhausted. Spraying equipment
shall be interlocked with the ventilation of the flammable
vapor area such that spraying operations cannot be con-
ducted unless the ventilation system is in operation.
502.7.2.2 Recirculation. Air exhausted from spraying
operations shall not be recirculated.
Exceptions:
1. Air exhausted from spraying operations shall
be permitted to be recirculated as makeup air
for unmanned spray operations provided that:
1.1. The solid particulate has been removed.
1.2. The vapor concentration is less than 25
percent of the lower flammable limit
(LFL).
1.3. Approved equipment is used to monitor
the vapor concentration.
1.4. An alarm is sounded and spray operations
are automatically shut down if the vapor
concentration exceeds 25 percent of the
LFL.
1 .5. In the event of shutdown of the vapor con-
centration monitor, 100 percent of the air
volume specified in Section 510 is auto-
matically exhausted.
2. Air exhausted from spraying operations is
allowed to be recirculated as makeup air to
manned spraying operations where all of the
conditions provided in Exception 1 are
included in the installation and documents have
been prepared to show that the installation does
not pose a life safety hazard to personnel inside
the spray booth, spraying space or spray room.
502.7.2.3 Air velocity. Ventilation systems shall be
designed, installed and maintained such that the average
air velocity over the open face of the booth, or booth cross
<
36
2007 OREGON MECHANICAL SPECIALTY CODE
EXHAUST SYSTEMS
section in the direction of airflow during spraying opera-
tions, is not less than 100 feet per minute (0.51 m/s).
502.7.2.4 Ventilation obstruction. Articles being
sprayed shall be positioned in a manner that does not
obstruct collection of overspray.
502.7.2.5 Independent ducts. Each spray booth and
spray room shall have an independent exhaust duct sys-
tem discharging to the outdoors.
Exceptions:
1 . Multiple spray booths having a combined fron-
tal area of 18 square feet (1.67 m^) or less are
allowed to have a common exhaust where iden-
tical spray-finishing material is used in each
booth. If more than one fan serves one booth,
such fans shall be interconnected so that all fans
operate simultaneously.
2. Where treatment of exhaust is necessary for air
pollution control or energy conservation, ducts
shall be allowed to be manifolded if all of the
following conditions are met:
2.1. The sprayed materials used are compatible
and will not react or cause ignition of the
residue in the ducts.
2.2. Nitrocellulose-based finishing material
shall not be used.
2.3. A filtering system shall be provided to
reduce the amount of overspray carried
into the duct manifold.
2.4. Automatic sprinkler protection shall be pro-
vided at the junction of each booth exhaust
with the manifold, in addition to the protec-
tion required by this chapter.
502.7.2.6 Fan motors and belts. Electric motors driving
exhaust fans shall not be placed inside booths or ducts.
Fan rotating elements shall be nonferrous or nonsparking
or the casing shall consist of, or be lined with, such mate-
rial. Belts shall not enter the duct or booth unless the belt
and pulley within the duct are tightly enclosed.
502.7.3 Dipping operations. Flammable vapor areas of dip
tank operations shall be provided with mechanical ventila-
tion adequate to prevent the dangerous accumulation of
vapors. Required ventilation systems shall be so arranged
that the failure of any ventilating fan will automatically stop
the dipping conveyor system.
502.7.4 Electrostatic apparatus. The flammable vapor
area in spray-finishing operations involving electrostatic
apparatus and devices shall be ventilated in accordance with
Section 502.7.2.
502.7.5 Powder coating. Exhaust ventilation for pow-
der-coating operations shall be sufficient to maintain the
atmosphere below one-half of the minimum explosive con-
centration for the material being applied. Nondeposited,
air-suspended powders shall be removed through exhaust
ducts to the powder recovery system.
502.8 Hazardous materials — general requirements.
Exhaust ventilation systems for structures containing hazard-
ous materials shall be provided as required in Sections 502.8.1
through 502.8.5.
502.8.1 Storage in excess of the maximum allowable
quantities. Indoor storage areas and storage buildings for
hazardous materials in amounts exceeding the maximum
allowable quantity per control area shall be provided with
mechanical exhaust ventilation or natural ventilation where
natural ventilation can be shown to be acceptable for the
materials as stored.
Exception: Storage areas for flammable solids comply-
ing with Section 3604 of the Fire Code.
502.8.1.1 System requirements. Exhaust ventilation
systems shall comply with all of the following:
1. The installation shall be in accordance with this
code.
2. Mechanical ventilation shall be provided at a rate
of not less than 1 cfm per square foot [0.00508
m3/(s • m^)] of floor area over the storage area.
3. The systems shall operate continuously unless |
alternate designs are approved.
4. A manual shutoff control shall be provided outside
of the room in a position adjacent to the access
door to the room or in another approved location.
The switch shall be a break-glass or other
approved type and shall be labeled: VENTILA-
TION SYSTEM EMERGENCY SHUTOFF.
5. The exhaust ventilation shall be designed to con-
sider the density of the potential fumes or vapors
released. For fumes or vapors that are heavier than
air, exhaust shall be taken from a point within 12
inches (305 mm) of the floor. For fumes or vapors
that are lighter than air, exhaust shall be taken from
a point within 12 inches (305 mm) of the highest
point of the room.
6. The location of both the exhaust and inlet air open-
ings shall be designed to provide air movement
across all portions of the floor or room to prevent
the accumulation of vapors.
7. The exhaust air shall not be recirculated to occu-
pied areas if the materials stored are capable of
emitting hazardous vapors and contaminants have
not been removed. Air contaminated with explo-
sive or flammable vapors, fumes or dusts; flamma-
ble, highly toxic or toxic gases; or radioactive
materials shall not be recirculated.
502.8.2 Gas rooms, exhausted enclosures and gas cabi-
nets. The ventilation system for gas rooms, exhausted
enclosures and gas cabinets for any quantity of hazardous
material shall be designed to operate at a negative pressure
in relation to the surrounding area. Highly toxic and toxic
gases shall also comply with Sections 502.9.7.1, 502.9.7.2
and 502.9.8.4.
502.8.3 Indoor dispensing and use. Indoor dispensing and
use areas for hazardous materials in amounts exceeding the
2007 OREGON MECHANICAL SPECIALTY CODE
37
EXHAUST SYSTEMS
maximum allowable quantity per control area shall be pro-
vided with exhaust ventilation in accordance with Section
502.7.1.
Exception: Ventilation is not required for dispensing
and use of flammable solids other than finely divided
particles.
502.8.4 Indoor dispensing and use — point sources.
Where gases, liquids or solids in amounts exceeding the
maximum allowable quantity per control area and having a
hazard ranking of 3 or 4 in accordance with NFPA 704 are
dispensed or used, mechanical exhaust ventilation shall be
provided to capture gases, fumes, mists or vapors at the
point of generation.
Exception: Where it can be demonstrated that the gases,
liquids or solids do not create harmful gases, fumes,
mists or vapors.
502.8.5 Closed systems. Where closed systems for the use
of hazardous materials in amounts exceeding the maximum
allowable quantity per control area are designed to be
opened as part of normal operations, ventilation shall be
provided in accordance with Section 502.8.4.
502.9 Hazardous materials — requirements for specific
materials. Exhaust ventilation systems for specific hazardous
materials shall be provided as required in Section 502.8 and
Sections 502.9.1 through 502.9.11.
502.9.1 Compressed gases — medical gas systems. Rooms
for the storage of compressed medical gases in amounts
exceeding the maximum allowable exempt quantity per
control area, and which do not have an exterior wall, shall be
exhausted through a duct to the exterior of the building.
Both separate airstreams shall be enclosed in a 1 -hour-rated
shaft enclosure from the room to the exterior. Approved
mechanical ventilation shall be provided at a minimum rate
of 1 cfm/ft2 [0.00508 mV(s • m^)] of the area of the room.
Gas cabinets for the storage of compressed medical gases
in amounts exceeding the maximum allowable quantity per
control area shall be connected to an exhaust system. The
average velocity of ventilation at the face of access ports or
windows shall be not less than 200 feet per minute (1.02
m/s) with a minimum velocity of 150 feet per minute (0.76
m/s) at any point at the access port or window.
502.9.2 Corrosives. Where corrosive materials in amounts
exceeding the maximum allowable quantity per control area
are dispensed or used, mechanical exhaust ventilation in
accordance with Section 502.8.4 shall be provided.
502.9.3 Cryogenics. Storage areas for stationary or porta-
ble containers of cryogenic fluids in any quantity shall be
ventilated in accordance with Section 502.8. Indoor areas
where cryogenic fluids in any quantity are dispensed shall
be ventilated in accordance with the requirements of Sec-
tion 502.8.4 in a manner that captures any vapor at the point
of generation.
Exception: Ventilation for indoor dispensing areas is not
required where it can be demonstrated that the cryogenic
fluids do not create harmful vapors.
502.9.4 Explosives, Squirrel cage blowers shall not be used
for exhausting hazardous fumes, vapors or gases in operat-
ing buildings and rooms for the manufacture, assembly or
testing of explosives. Only nonferrous fan blades shall be
used for fans located within the ductwork and through
which hazardous materials are exhausted. Motors shall be
located outside the duct.
502.9.5 Flammable and combustible liquids. Exhaust
ventilation systems shall be provided as required by Sec-
tions 502.9.5.1 through 502.9.5.5 for the storage, use, dis-
pensing, mixing and handling of flammable and
combustible liquids. Unless otherwise specified, this sec-
tion shall apply to any quantity of flammable and combusti-
ble liquids.
Exception: This section shall not apply to flammable
and combustible liquids that are exempt from the Fire
Code.
502.9.5.1 Vaults. Vaults that contain tanks of Class I liq-
uids shall be provided with continuous ventilation at a
rate of not less than 1 cfm/ft^ of floor area [0.00508 m3/(s
• m^)], but not less than 150 cfm (4 mVmin). Failure of
the exhaust airflow shall automatically shut down the
dispensing system. The exhaust system shall be
designed to provide air movement across all parts of the
vault floor. Supply and exhaust ducts shall extend to a
point not greater than 12 inches (305 mm) and not less
than 3 inches (76 mm) above the floor. The exhaust sys-
tem shall be installed in accordance with the provisions
of NFPA 9 1 . Means shall be provided to automatically
detect any flammable vapors and to automatically shut
down the dispensing system upon detection of such
flammable vapors in the exhaust duct at a concentration
of 25 percent of the LFL.
502.9.5.2 Storage rooms and warehouses. Liquid stor-
age rooms and liquid storage warehouses for quantities
of liquids exceeding those specified in the Fire Code
shall be ventilated in accordance with Section 502.8.1.
502.9.5.3 Cleaning machines. Areas containing
machines used for parts cleaning in accordance with the
Fire Code shall be adequately ventilated to prevent accu-
mulation of vapors.
502.9.5.4 Use, dispensing and mixing. Continuous
mechanical vendlation shall be provided for the use, dis-
pensing and mixing of flammable and combustible liq-
uids in open or closed systems in amounts exceeding the
maximum allowable quantity per control area and for
bulk transfer and process transfer operations. The venti-
lation rate shall be not less than 1 cfm/ft^ [0.00508 mV(s »
m^)] of floor area over the design area. Provisions shall
be made for the introduction of makeup air in a manner
that will include all floor areas or pits where vapors can
collect. Local or spot ventilation shall be provided where
needed to prevent the accumulation of hazardous vapors.
Exception: Where natural ventilation can be shown
to be effective for the materials used, dispensed, or
mixed.
38
2007 OREGON MECHANICAL SPECIALTY CODE
EXHAUST SYSTEMS
502.9.5.5 Bulk plants or terminals. Ventilation shall be
provided for portions of properties where flammable and
combustible liquids are received by tank vessels, pipe-
lines, tank cars or tank vehicles and which are stored or
blended in bulk for the purpose of distributing such liq-
uids by tank vessels, pipelines, tank cars, tank vehicles or
containers as required by Sections 502.9.5.5.1 through
502.9.5.5.3.
502.9.5.5.1 General. Ventilation shall be provided
for rooms, buildings and enclosures in which Class I
liquids are pumped, used or transferred. Design of
ventilation systems shall consider the relatively high
specific gravity of the vapors. Where natural ventila-
tion is used, adequate openings in outside walls at
floor level, unobstructed except by louvers or coarse
screens, shall be provided. Where natural ventilation
is inadequate, mechanical ventilation shall be pro-
vided.
502.9.5.5.2 Basements and pits. Class I liquids shall
not be stored or used within a building having a base-
ment or pit into which flammable vapors can travel,
unless such area is provided with ventilation designed
to prevent the accumulation of flammable vapors
therein.
502.9.5.5.3 Dispensing of Class I liquids. Contain-
ers of Class I liquids shall not be drawn from or filled
within buildings unless a provision is made to prevent
the accumulation of flammable vapors in hazardous
concentrations. Where mechanical ventilation is
required, it shall be kept in operation while flammable
vapors could be present.
502.9.6 Highly toxic and toxic liquids. Ventilation exhaust
shall be provided for highly toxic and toxic liquids as
required by Sections 502.9.6.1 and 502.9.6.2.
502.9.6.1 Treatment system. This provision shall apply
to indoor and outdoor storage and use of highly toxic and
toxic liquids in amounts exceeding the maximum allow-
able quantities per control area. Exhaust scrubbers or
other systems for processing yapors of highly toxic liquids
shall be provided where a spill or accidental release of
such liquids can be expected to release highly toxic vapors
at normal temperature and pressure.
502.9.6.2 Open and closed systems. Mechanical
exhaust ventilation shall be provided for highly toxic and
toxic liquids used in open systems in accordance with
Section 502.8.4. Mechanical exhaust ventilation shall be
provided for highly toxic and toxic liquids used in closed
systems in accordance with Section 502.8.5.
Exception; Liquids or solids that do not generate
highly toxic or toxic fumes, mists or vapors.
502.9.7 Highly, toxic and toxic compressed gases— any
quantity. Ventilation exhaust shall be provided for highly
toxic and toxic compressed gases in any quantity as required
by Sections 502.9.7.1 and 502.9.7.2.
502.9.7.1 Gas cabinets. Gas cabinets containing highly
toxic or toxic compressed gases in any quantity shall-
comply with Section 502.8.2 and the following require-
ments:
1. The average ventilation velocity at the face of gas
cabinet access ports or windows shall be not less
than 200 feet per minute (1.02 m/s) with a mini-
mum velocity of 150 feet per minute (0.76 m/s) at
any point at the access port or window.
2. Gas cabinets shall be connected to an exhaust sys-
tem.
3. Gas cabinets shall not be used as the sole means of
exhaust for any room or area.
502.9.7.2 Exhausted enclosures. Exhausted enclosures
containing highly toxic or toxic compressed gases in any
quantity shall comply with Section 502.8.2 and the fol-
lowing requirements:
1. The average ventilation velocity at the face of the
enclosure shall be not less than 200 feet per minute
(1 .02 m/s) with a minimum velocity of 150 feet per
minute (0.76 m/s).
2. Exhausted enclosures shall be connected to an
exhaust system.
3. Exhausted enclosures shall not be used as the sole
means of exhaust for any room or area.
502.9.8 Highly toxic and toxic compressed gases^quan-
tities exceeding the maximum allowable quantity per
control area. Ventila.tion exhaust shall be provided for
highly toxic and toxic compressed gases in amounts
exceeding the maximum allowable quantities per control
area as required by Sections 502.9.8.1 through 502.9.8.6.
502.9.8.1 Ventilated areas. The room or area in which
indoor gas cabinets or exhausted enclosures are located
shall be provided with exhaust ventilation. Gas cabinets
or exhausted enclosures shall not be used as the sole
means of exhaust for any room or area.
502.9.8.2 Local exhaust for portable tanks. A means
of local exhaust shall be provided to capture leakage
from indoor and outdoor portable tanks. The local
exhaust shall consist of portable ducts or collection sys-
tems designed to be applied to the site of a leak in a valve
or fitting on the tank. The local exhaust system shall be
located in a gas room. Exhaust shall be directed to a treat-
ment system where required by the Fire Code.
502.9.8.3 Piping and controls — stationary tanks. Fill-
ing or dispensing connections on indoor stationary tanks
shall be provided with a means of local exhaust. Such
exhaust shall be designed to capture fumes and vapors.
The exhaust shall be directed to a treatment system
where required by the Fire Code.
502.9.8.4 Gas rooms. The ventilation system for gas
rooms shall be designed to operate at a negative pressure
in relation to the surrounding area. The exhaust ventila-
tion from gas rooms shall be directed to an exhaust sys-
tem.
502.9.8.5 Treatment system. The exhaust ventilation
from gas cabinets, exhausted enclosures and gas rooms.
2007 OREGON WIECHANICAL SPECBALTV CODE
39
EXHAUST SYSTEMS
and local exhaust systems required in Sections 502.9.8.2
and 502.9.8.3 shall be directed to a treatment system
where required by the Fire Code.
502,9.8.6 Process equipment. Effluent from indoor and
outdoor process equipment containing highly toxic or
toxic compressed gases which could be discharged to the
atmosphere shall be processed through an exhaust scrub-
ber or other processing system. Such systems shall be in
accordance with the Fire Code.
502.9.9 Ozone gas generators. Ozone cabinets and ozone
gas-generator rooms for systems having a maximum
ozone-generating capacity of one-half pound (0.23 kg) or
more over a 24-hour period shall be mechanically ventilated
at a rate of not less than six air changes per hour. For cabi-
nets, the average velocity of ventilation at makeup air open-
ings with cabinet doors closed shall be not less than 200 feet
per minute (1.02 m/s).
502.9.10 LP-gas distribution facilities, LP-gas distribu-
tion facilities shall be ventilated in accordance with NFPA
58.
502.9.10.1 Portable container use. Above-grade under-
floor spaces or basements in which portable LP-gas con-
tainers are used or are stored awaiting use or re-sale shall
be provided with an approved means of ventilation.
Exception: Department of Transportation (DOT)
specification cylinders with a maximum water capac-
ity of 2.5 pounds (1 kg) for use in completely self-con-
tained hand torches and similar applications. The
quantity of LP-gas shall not exceed 20 pounds (9 kg).
502.9.11 Silane gas. Exhausted enclosures and gas cabinets
for the indoor storage of silane gas in amounts exceeding the
maximum allowable quantities per control area shall com-
ply with this section.
1. Exhausted enclosures and gas cabinets shall be in
accordance with Section 502.8.2.
2. The velocity of ventilation across unwelded fittings
and connections on the piping system shall not be less
than 200 feet per minute (1.02 m/s).
3. The average velocity at the face of the access ports or
windows in the gas cabinet shall not be less than 200
feet per minute ( 1 .02 m/s) with a minimum velocity of
150 feet per minute (0.76 m/s) at any point at the
access port or window.
502.10 Hazardous production materials (HPM). Exhaust
ventilation systems and materials for ducts utilized for the
exhaust of HPM shall comply with this section, other applica-
ble provisions of this code, the Building Code and the Fire
Code.
[F]502.10.1 Where required. Exhaust ventilation systems
shall be provided in the following locations in accordance
with the requirements of this section and the Building Code.
1 . Fabrication areas: Exhaust ventilation for fabrica-
tion areas shall comply with the Building Code. Addi-
tional manual control switches shall be provided
where required by the code official.
2. Workstations: A ventilation system shall be pro-
vided to capture and exhaust gases, fumes and vapors |
at workstations.
3. Liquid storage rooms: Exhaust ventilation for liquid
storage rooms shall comply with Section 502.8.1.1
and the Building Code.
4. HPM rooms: Exhaust ventilation for HPM rooms
shall comply with Section 502.8. 1.1 and the Building
Code.
5. Gas cabinets: Exhaust ventilation for gas cabinets
shall comply with Section 502.8.2. The gas cabinet
ventilation system is allowed to connect to a worksta-
tion ventilation system. Exhaust ventilation for gas
cabinets containing highly toxic or toxic gases shall
also comply with Sections 502.9.7 and 502.9.8.
6. Exhausted enclosures: Exhaust ventilation for
exhausted enclosures shall comply with Section
502.7.2. Exhaust ventilation for exhausted enclosures
containing highly toxic or toxic gases shall also com-
ply with Sections 502.9.7 and 502.9.8.
7. Gas rooms: Exhaust ventilation for gas rooms shall
comply with Section 502.8.2. Exhaust ventilation for
gas cabinets containing highly toxic or toxic gases
shall also comply with Sections 502.9.7 and 502.9.8.
502.10.2 Penetrations. Exhaust ducts penetrating fire bar-
rier assemblies shall be contained in a shaft of equivalent
fire-resistive construction. Exhaust ducts shall not penetrate
building separation walls. Fire dampers shall not be
installed in exhaust ducts.
502.10.3 Treatment systems. Treatment systems for highly
toxic and toxic gases shall comply with the Fire Code.
502.11 Motion picture projectors. Motion picture projectors
shall be exhausted in accordance with Section 502.11.1 or
502.11.2.
502.11.1 Projectors with an exhaust discharge. Projec-
tors equipped with an exhaust discharge shall be directly
connected to a mechanical exhaust system. The exhaust sys-
tem shall operate at an exhaust rate as indicated by the man-
ufacturer's installation instructions.
502.11.2 Projectors without exhaust connection. Projec-
tors without an exhaust connection shall have contaminants
exhausted through a mechanical exhaust system. The
exhaust rate for electric arc projectors shall be a minimum of
200 cubic feet per minute (cfm) (0.09 mVs) per lamp. The
exhaust rate for xenon projectors shall be a minimum of 300
cfm (0.14 mVs) per lamp. Xenon projector exhaust shall be
at a rate such that the exterior temperature of the lamp hous-
ing does not exceed 130°F (54°C). The lamp and projection
room exhaust systems, whether combined or independent,
shall not be interconnected with any other exhaust or return
system within the building.
502.12 Organic coating processes. Enclosed structures
involving organic coating processes in which Class I liquids are
processed or handled shall be ventilated at a rate of not less than
1 cfm/ft2 [0.00508 mV{s ■ m^)] of solid floor area. Ventilation
shall be accomplished by exhaust fans that intake at floor levels
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and discharge to a safe location outside the structure.
Noncontaminated intake air shall be introduced in such a man-
ner that all portions of solid floor areas are provided with con-
tinuous uniformly distributed air movement.
502.13 Public garages. Mechanical exhaust systems for pub-
lic garages, as required in Chapter 4, shall operate continuously
or in accordance with Section 404.
502.14 Motor vehicle operation. In areas where motor vehi-
cles operate, mechanical ventilation shall be provided in accor-
dance with Section 403. Additionally, areas in which stationary
motor vehicles are operated shall be provided with a source
capture system that connects directly to the motor vehicle
exhaust systems.
Exceptions:
1 . This section shall not apply where the motor vehicles
being operated or repaired are electrically powered.
2. This section shall not apply to one- and two-family
dwellings.
3. This section shall not apply to motor vehicle service
areas where engines are operated inside the building
only for the duration necessary to move the motor
vehicles in and out of the building.
502.15 Repair garages. Where Class I liquids or LP-gas are
stored or used within a building having a basement or pit
wherein flammable vapors could accumulate, the basement or
pit shall be provided with ventilation designed to prevent the
accumulation of flammable vapors therein.
502.16 Repair garages for natural gas- and hydro-
gen-fueled vehicles. Repair garages used for the repair of natu-
ral gas- or hydrogen-fueled vehicles shall be provided with an
approved mechanical ventilation system. The mechanical ven-
tilation system shall be in accordance with Sections 502.16.1
and 502.16.2.
Exception: Where approved by the code official, natural
ventilation shall be permitted in lieu of mechanical ventila-
tion.
502.16.1 Design. Indoor locations shall be ventilated utiliz-
ing air supply inlets and exhaust outlets arranged to provide
uniform air movement to the extent practical. Inlets shall be
uniformly arranged on exterior walls near floor level. Out-
lets shall be located at the high point of the room in exterior
walls or the roof.
Ventilation shall be by a continuous mechanical ventila-
tion system or by a mechanical ventilation system activated
by a continuously monitoring natural gas detection system,
or for hydrogen, a continuously monitoring flammable gas
detection system, each activating at a gas concentration of
25 percent of the lower flammable limit (LFL). In all cases,
the system shall shut down the fueling system in the event of
failure of the ventilation system.
The ventilation rate shall be at least 1 cubic foot per min-
ute per 12 cubic feet [0.00138 m¥(s • m^)] of room volume.
502.16.2 Operation. The mechanical ventilation system
shall operate continuously.
Exceptions:
1. Mechanical ventilation systems that are inter-
locked with a gas detection system designed in
accordance with the Fire Code.
2. Mechanical ventilation systems in garages that are
used only for the repair of vehicles fueled by liquid
fuels or odorized gases, such as CNG, where the
ventilation system is electrically interlocked with
the lighting circuit.
502.17 Tire rebuilding or recapping. Each room where rub-
ber cement is used or mixed, or where flammable or combusti-
ble solvents are applied, shall be ventilated in accordance with
the applicable provisions of NFPA 9 1 .
502.17.1 Buffing machines. Each buffing machine shall be
connected to a dust-collecting system that prevents the
accumulation of the dust produced by the buffing process.
502.18 Specific rooms. Specific rooms, including bathrooms,
locker rooms, smoking lounges and toilet rooms, shall be
exhausted in accordance with the ventilation requirements of
Chapter 4.
502.19 Indoor firing ranges. Ventilation shall be provided in
an approved manner in areas utilized as indoor firing ranges.
SECTION 503
MOTORS AND FANS
503.1 General. Motors and fans shall be sized to provide the
required air movement. Motors in areas that contain flammable
vapors or dusts shall be of a type approved for such environ-
ments. A manually operated remote control installed at an
approved location shall be provided to shut off fans or blowers
in flammable vapor or dust systems. Electrical equipment and
appliances used in operations that generate explosive or flam-
mable vapors, fumes or dusts shall be interlocked with the ven-
tilation system so that the equipment and appliances cannot be
operated unless the ventilation fans are in operation. Motors for
fans used to convey flammable vapors or dusts shall be located
outside the duct or shall be protected with approved shields and
dustproofmg. Motors and fans shall be provided with a means
of access for servicing and maintenance.
503.2 Fans. Parts of fans in contact with explosive or flamma-
ble vapors, fumes or dusts shall be of nonferrous or
nonsparking materials, or their casing shall be lined or con-
structed of such material. When the size and hardness of mate-
rials passing through a fan are capable of producing a spark,
both the fan and the casing shall be of nonsparking materials.
When fans are required to be spark resistant, their bearings
shall not be within the airstream, and all parts of the fan shall be
grounded. Fans in systems-handling materials that are capable
of clogging the blades, and fans in buffimg or woodworking
exhaust systems, shall be of the radial-blade or tube-axial type.
503.3 Equipment and appliances identification plate.
Equipment and appliances used to exhaust explosive or flam-
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>
mable vapors, fumes or dusts shall bear an identification plate
stating the ventilation rate for which the system was designed.
503.4 Corrosion=resistant fans. Fans located in systems con-
veying corrosives shall be of materials that are resistant to the
corrosive or shall be coated with corrosion-resistant materials.
SECTION 504
CLOTHES DRYER EXHAUST
504.1 Installation. Clothes dryers shall be exhausted in accor-
dance with the manufacturer's instructions. Dryer exhaust sys-
tems shall be independent of all other systems and shall convey
the moisture and any products of combustion to the outside of
the building.
Exception: This section shall not apply to listed and labeled
condensing (ductless) clothes dryers.
504.2 Exhaust penetrations. Ducts that exhaust clothes dry-
ers shall not penetrate or be located within any fireblocking,
draftstopping or any wall, floor/ceiling or other assembly
required by the Building Code to be fire-resistance rated,
unless such duct is constructed of galvanized steel or aluminum
of the thickness specified in Section 603.4 and the fire-resis-
tance rating is maintained in accordance with the Building
Code. Fire dampers, combination fire/smoke dampers and any
similar devices that will obstruct the exhaust flow, shall be pro-
hibited in clothes dryer exhaust ducts.
504.3 Cleanout. Each vertical riser shall be provided with a
means for cleanout.
504.4 Exhaest installation. Dryer exhaust ducts for clothes
dryers shall terminate on the outside of the building and shall
be equipped with a backdraft damper. Screens shall not be
installed at the duct termination. Ducts shall not be connected
or installed with sheet metal screws or other fasteners that will
obstruct the exhaust flow. Clothes dryer exhaust ducts shall not
be connected to a vent connector, vent or chimney. Clothes
dryer exhaust ducts shall not extend into or through ducts or
plenums.
504.5 Makeup air. Installafions exhausting more than 200 cfm
(0.09 m^/s) shall be provided with makeup air. Where a closet is
designed for the installation of a clothes dryer, an opening hav-
ing an area of not less than 100 square inches (0.0645 m^) shall
be provided in the closet enclosure.
504.6 Domestic clothes dryer ducts. Exhaust ducts for
domestic clothes dryers shall be constructed of metal and shall
have a smooth interior finish. The exhaust duct shall be a mini-
mum nominal size of 4 inches (102 mm) in diameter. The entire
exhaust system shall be supported and secured in place. The
male end of the duct at overlapped duct joints shall extend in
the direction of airflow. Clothes dryer transition ducts used to
connect the appliance to the exhaust duct system shall be lim-
ited to single lengths not to exceed 8 feet (2438 mm). Transi-
tion ducts shall not be concealed within construction.
504.6.1 Maximum length. The maximum length of a
clothes dryer exhaust duct shall not exceed 25 feet (7620
mm) from the dryer location to the outlet terminal. The
maximum length of the duct shall be reduced 2V2 feet (762
mm) for each 45 degree (0.79 rad) bend and 5 feet (1524
mm) for each 90 degree (1.6 rad) bend. The maximum
length of the exhaust duct does not include the transition
duct.
Exception: Where the make and model of the clothes
diyer to be installed is known and the manufacturer's
installation instructions for such dryer are provided to the
code official, the maximum length of the exhaust duct,
including any transition duct, shall be permitted to be in
accordance with the dryer manufacturer's installation
instructions.
504.6.2 Rough-in required. Where a compartment or
space for a domestic clothes dryer is provided, an exhaust
duct system shall be installed in accordance with Sections
504.6 and 504.6.1.
504.7 Commercial clothes dryers. The installation of dryer
exhaust ducts serving Type 2 clothes dryers shall comply with
the appliance manufacturer's installation instructions. Exhaust
fan motors installed in exhaust systems shall be located outside
of the airstream. In multiple installations, the fan shall operate
continuously or be interlocked to operate when any individual
unit is operating. Ducts shall have a minimum clearance of 6
inches (152 mm) to combustible materials. Clothes dryer tran-
sition ducts used to connect the appliance to the exhaust duct
system shall be limited to single lengths not to exceed 8 feet
(2438 mm) in length and shall be listed and labeled for the
application. Transition ducts shall not be concealed within con-
struction.
SECT80N 505
DOMESTIC KITCHEN EXHAUST EQ8
iEi
505.1 Domestic systems. Where domestic range hoods and
domestic appliances equipped with downdraft exhaust are
located within dwelling units, such hoods and appliances shall
discharge to the outdoors through sheet metal ducts con-
structed of galvanized steel, stainless steel, aluminum or cop-
per. Such ducts shall have smooth inner walls and shall be air
tight and equipped with a backdraft damper.
Exceptions:
1. Where installed in accordance with the manufac-
turer's installation instructions and where mechanical
or natural ventilation is otherwise provided in accor-
dance with Chapter 4, listed and labeled ductless
range hoods shall not be required to discharge to the
outdoors.
2. Ducts for domestic kitchen cooking appliances
equipped with downdraft exhaust systems shall be
permitted to be constructed of Schedule 40 PVC pipe
provided that the installation complies with all of the
following:
2. 1 . The duct shall be installed under a concrete slab
poured on grade.
2.2. The underfloor trench in which the duct is
installed shall be completely backfilled with
sand or gravel.
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2.3. The PVC duct shall extend not greater than 1
inch (25 mm) above the indoor concrete floor
surface.
2.4. The PVC duct shall extend not greater than 1
inch (25 mm) above grade outside of the build-
ing.
2.5. The PVC ducts shall be solvent cemented.
SECTION 506
COMMERCIAL KITCHEN HOOD VENTILATION
SYSTEM DUCTS AND EXHAUST EQUIPMENT
506.1 GeneraL Commercial kitchen hood ventilation ducts
and exhaust equipment shall comply with the requirements of
this section. Commercial kitchen grease ducts shall be
designed for the type of cooking appliance and hood served.
506.2 Corrosion protection. Ducts exposed to the outside
atmosphere or subject to a corrosive environment shall be pro-
tected against corrosion in an approved manner.
506.3 Ducts serving Type I hoods. Type I exhaust ducts shall
be independent of all other exhaust systems except as provided
in Section 506.3.5. Commercial kitchen duct systems serving
Type I hoods shall be designed, constructed and installed in
accordance with Sections 506.3.1 through 506.3.12.3.
506.3.1 Duct materials. Ducts serving Type I hoods shall
be constructed of materials in accordance with Sections
506.3.1.1 and 506.3. 1.2.
506.3.1.1 Grease duct materials. Grease ducts serving
Type I hoods shall be constructed of steel not less than
0.055 inch (1.4 mm) (No. 16 Gage) in thickness or stain-
less steel not less than 0.044 inch (1.1 mm) (No. 18
Gage) in thickness.
Exception: Listed and labeled factory-built commer-
cial kitchen grease ducts shall be installed in accor-
dance with Section 304.1.
506.3.1.2 Makeup air ducts. Make up air ducts connect-
ing to or within 1 8 inches (457 mm) of a Type I hood shall
be constructed and installed in accordance with Sections
603.1, 603.3, 603.4, 603.9, 603.10 and 603.12. Duct
insulation installed within 18 inches (457 mm) of a Type
I hood shall be noncombustible or shall be listed for the
application.
506.3.2 Joints, seams and penetrations of grease ducts.
Joints, seams and penetrations of grease ducts shall be made
with a continuous liquid-tight weld or braze made on the
external surface of the duct system.
Exceptions:
1 . Penetrations shall not be required to be welded or
brazed where sealed by devices that are listed for
the application.
2. Internal welding or brazing shall not be prohibited
provided that the joint is formed or ground smooth
and is provided with ready access for inspection.
3. Factory-built commercial kitchen grease ducts
listed and labeled in accordance with UL 1978 and
installed in accordance with Section 304.1.
506.3.2.1 Duct joint types. Duct joints shall be butt
joints or overlapping duct joints of either the telescoping
or bell type. Overlapping joints shall be installed to pre-
vent ledges and obstructions from collecting grease or
interfering with gravity drainage to the intended collec-
tion point. The difference between the inside cross-sec-
tional dimensions of overlapping sections of duct shall
not exceed 0.25 inch (6 mm). The length of overlap for
overlapping duct joints shall not exceed 2 inches (5 1
mm).
506.3.2.2 Duct-to-hood joints. Duct-to-hood joints
shall be made with continuous internal or external liq-
uid-tight welded or brazed joints. Such joints shall be
smooth, accessible for inspection, and without grease
traps.
Exceptions: This section shall not apply to:
1 . A vertical duct-to-hood collar connection made
in the top plane of the hood in accordance with
all of the following:
1.1. The hood duct opening shall have a
1 -inch-deep (25 mm), full perimeter,
welded flange turned down into the hood
interior at an angle of 90 degrees from the
plane of the opening.
1 .2. The duct shall have a 1 -inch-deep (25 mm)
flange made by a 1-inch by 1-inch (25 mm
by 25 mm) angle iron welded to the full
perimeter of the duct not less than 1 inch
(25 mm) above the bottom end of the duct.
1.3. A gasket rated for use at not less than
1,500°F (815°C) is installed between the
duct flange and the top of the hood.
1.4. The duct-to-hood joint shall be secured by
stud bolts not less than 0.25 inch (6.4 mm)
in diameter welded to the hood with a spac-
ing not greater than 4 inches (102 mm) on
center for the full perimeter of the opening.
All bolts and nuts are to be secured with
lockwashers.
2. Listed and labeled duct-to-hood collar connec-
tions installed in accordance with Section
304.1.
506.3.2.3 Duct-to-exhaust fan connections. Duct-
to-exhaust fan connections shall be flanged and gasketed
at the base of the fan for vertical discharge fans; shall be
flanged, gasketed and bolted to the inlet of the fan for
side-inlet utility fans; and shall be flanged, gasketed and
bolted to the inlet and outlet of the fan for in-line fans.
506.3.2.4 Vibration isolation. A vibration isolation
connector for connecting a duct to a fan shall consist of
noncombustible packing in a metal sleeve joint of
approved design or shall be a coated-fabric flexible duct
connector Hsted and labeled for the application. Vibra-
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>
tion isolation connectors shall be installed only at the
connection of a duct to a fan inlet or outlet.
506.3.3 Grease duct supports. Grease duct bracing and
supports shall be of noncombustible material securely
attached to the structure and designed to carry gravity and
seismic loads within the stress limitations of the Building
Code. Bolts, screws, rivets and other mechanical fasteners
shall not penetrate duct walls.
506.3.4 Air velocity. Grease duct systems serving a Type I
hood shall be designed and installed to provide an air veloc-
ity within the duct system of not less than 500 feet per min-
ute (2.5 m/s).
Exception: The velocity limitations shall not apply
within duct transitions utilized to connect ducts to differ-
ently sized or shaped openings in hoods and fans, pro-
vided that such transitions do not exceed 3 feet (914 mm)
in length and are designed to prevent the trapping of
grease.
506.3.5 Separation of grease duct system. A separate
grease duct system shall be provided for each Type I hood.
A separate grease duct system is not required where all of
the following conditions are met:
1 . All interconnected hoods are located within the same
story.
2. All interconnected hoods are located within the same
room or in adjoining rooms.
3. Interconnecting ducts do not penetrate assemblies
required to be fire-resistance rated.
4. The grease duct system does not serve solid fuel-fired
appliances.
506.3.6 Grease duct clearances. Grease duct systems and
exhaust equipment serving a Type I hood shall have a clear-
ance to combustible construction of not less than 1 8 inches
(457 mm), and shall have a clearance to noncombustible
construction and gypsum wallboard attached to
noncombustible structures of not less than 3 inches (76
mm).
Exception: Listed and labeled factory-built commercial
kitchen grease ducts and exhaust equipment installed in
accordance with Section 304. 1 .
506.3.7 Prevention of grease accumulation in grease
ducts. Duct systems serving a Type I hood shall be con-
structed and installed so that grease cannot collect in any
portion thereof, and the system shall slope not less than
one-fourth unit vertical in 12 units horizontal (2-percent
slope) toward the hood or toward an approved grease reser-
voir. Where horizontal ducts exceed 75 feet (22 860 mm) in
length, the slope shall not be less than one unit vertical in 12
units horizontal (8.3-percent slope).
506.3.7.1 Grease diverter. Where a centrifugal fan with
horizontal discharge is located outside the building, such
fan shall be provided with a duct or duct fitting connected
to the fan outlet that diverts the discharge from the grease
exhaust duct system in an upward direction. Such
diverter duct or fitting shall comply with the following:
1. The duct or duct fitting shall be constructed of
metal as set forth in Chapter 6.
2. The maximum total developed length of the duct
or duct fitting measured along the centerline shall
not exceed three times the vertical dimension of
the fan outlet.
3. The duct or duct fitting shall be provided with
openings at the lowest point to permit drainage of
grease to an approved collection device.
506.3.8 Grease duct cleanouts and other openings.
Grease duct systems shall not have openings therein other
than those required for proper operation and maintenance of
the system. Any portion of such system having sections not
provided with access from the duct entry or dischcU"ge shall
be provided with cleanout openings. Cleanout openings
shall be equipped with tight-fitting doors constructed of
steel having a thickness not less than that required for the
duct. Doors shall be equipped with a substantial method of
latching, sufficient to hold the door tightly closed. Doors
shall be designed so that they are operable without the use of
a tool. Door assemblies, including any frames and
gasketing, shall be approved for the purpose, and shall not
have fasteners that penetrate the duct. Listed and labeled
access door assemblies shall be installed in accordance with
the terms of the listing.
506.3.8.1 Personnel entry. Where ductwork is large
enough to allow entry of personnel, not less than one
approved or listed opening having dimensions not less
thfin 20 inches by 20 inches (508 mm by 508 mm) shall
be provided in the horizontal sections, and in the top of
vertical risers. Where such entry is provided, the duct and
its supports shall be capable of supporting the additional
load and the cleanouts specified in Section 506.3.8 are
not required.
506.3.9 Grease duct horizontal cleanouts. Cleanouts
located on horizontal sections of ducts shall be spaced not
more than 20 feet (6096 mm) apart. The cleanouts shall be
located on the side of the duct with the opening not less than
1.5 inches (38 mm) above the bottom of the duct, and not
less than 1 inch (25 mm) below the top of the duct. The
opening minimum dimensions shall be 12 inches (305 mm)
on each side. Where the dimensions of the side of the duct
prohibit the cleanout installation prescribed herein, the
openings shall be on the top of the duct or the bottom of the
duct. Where located on the top of the duct, the opening
edges shall be a minimum of 1 inch (25 mm) from the edges
of the duct. Where located in the bottom of the duct,
cleanout openings shall be designed to provide internal
damming around the opening, shall be provided with
gasketing to preclude grease leakage, shall provide for
drainage of grease down the duct around the dam, and shall
be approved for the application. Where the dimensions of
2007 OREGON MECHANICAL SPECIALTY CODE
EXHAUST SYSTEMS
the sides, top or bottom of the duct preclude the installation
of the prescribed minimum- size cleanout opening, the
cleanout shall be located on the duct face that affords the
largest opening dimension and shall be installed with the
opening edges at the prescribed distances from the duct
edges as previously set forth in this section.
506.3.10 Grease duct enclosure. A grease duct serving a
Type I hood that penetrates a ceiling, wall or floor shall be
enclosed from the point of penetration to the outlet terminal.
A duct shall penetrate exterior walls only at locations where
unprotected openings are permitted by the Building Code.
Ducts shall be enclosed in accordance with the Building
Code requirements for shaft construction. The duct enclo-
sure shall be sealed around the duct at the point of penetra-
tion and vented to the outside of the building through the use
of weather-protected openings. Clearance from the duct to
the interior surface of enclosures of combustible construc-
tion shall be not less than 18 inches (457 mm). Clearance
from the duct to the interior surface of enclosures of
noncombustible construction or gypsum wall board
attached to noncombustible structures shall be not less than
6 inches (152 mm). The duct enclosure shall serve a single
grease exhaust duct system and shall not contain any other
ducts, piping, wiring or systems.
Exceptions:
1 . The shaft enclosure provisions of this section shall
not be required where a duct penetration is pro-
tected with a through-penetration firestop system
classified in accordance with ASTM E 814 and
having an "F" and "T" rating equal to the fire-resis-
tance rating of the assembly being penetrated and
where the surface of the duct is continuously cov-
ered on all sides from the point at which the duct
penetrates a ceiling, wall or floor to the outlet ter-
minal with a classified and labeled material, sys-
tem, method of construction or product
specifically evaluated for such purpose, in accor-
dance with ASTM E 2336. Exposed ductwrap sys-
tems shall be protected where subject to physical
damage.
2. The shaft enclosure provisions of this section
shall not be required where a duct penetration is
protected with a through-penetration firestop sys-
tem classified in accordance with ASTM E 814
and having an "F" and "T" rating equal to the fire
resistance rating of the assembly being penetrated
and where a prefabricated grease duct enclosure
assembly is protected on all sides from the point
at which the duct penetrates a ceiling, wall or
floor to the outlet terminal with a classified and
labeled prefabricated system specifically evalu-
ated for such purposes in accordance with UL
2221.
3. A duct enclosure shall not be required for a grease
duct that penetrates only a nonfire-resistance-rated
roof/ceiling assembly.
506.3.11 Grease duct fire-resistive access opening.
Where cleanout openings are located in ducts within a
fire-resistance-rated enclosure, access openings shall be
provided in the enclosure at each cleanout point. Access
openings shall be equipped with tight-fitting sliding or
hinged doors that are equal in fire-resistive protection to that
of the shaft or enclosure. An approved sign shall be placed
on access opening panels with wording as follows:
'ACCESS PANEL. DO NOT OBSTRUCT."
506.3.12 Exhaust outlets serving Type I hoods. Exhaust
outlets for grease ducts serving Type I hoods shall conform
to the requirements of Sections 506.3.12.1 through
506.3.12.3.
506.3.12.1 Termination above the roof. Exhaust out-
lets that terminate above the roof shall have the discharge
opening located not less than 40 inches (1016 mm) above
the roof surface.
506.3.12.2 Termination through an exterior wall.
Exhaust outlets shall be permitted to terminate through
exterior walls where the smoke, grease, gases, vapors,
and odors in the discharge from such terminations do not
create a public nuisance or a fire hazard. Such termina-
tions shall not be located where protected openings are
required by the Building Code. Other exterior openings
shall not be located within 3 feet (914 mm) of such termi-
nations.
506.3.12.3 Termination location. Exhaust outlets
shall be located not less than 10 feet (3048 mm) hori-
zontally from parts of the same or contiguous buildings,
adjacent buildings, adjacent property lines and air
intake openings into any building and shall be located
not less than 10 feet (3048 mm) above the adjoining
grade level.
Exception: Exhaust outlets shall terminate not less
than 5 feet (1524 mm) from parts of the same or con-
tiguous building, an adjacent building, adjacent prop-
erty line and air intake openings into a building where
air from the exhaust outlet discharges away from such
locations.
506.4 Ducts serving Type II hoods. Single or combined Type
II exhaust systems for food-processing operations shall be
independent of all other exhaust systems. Commercial kitchen
exhaust systems serving Type II hoods shall comply with Sec-
tions 506.4.1 and 506.4.2.
506.4.1 Type II exhaust outlets. Exhaust outlets for ducts
serving Type II hoods shall comply with Sections 401 .4 and
401.4.2. Such outlets shall be protected against local
weather conditions and shall meet the provisions for exte-
rior wall opening protectives in accordance with the Build-
ing Code.
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506,4.2 Ducts. Ducts and plenums serving Type II hoods
shall be constructed of rigid metallic materials. Duct con-
struction, installation, bracing and supports shall comply
with Chapter 6. Ducts subject to positive pressure and ducts
conveying moisture-laden or waste-heat-laden air shall be
constructed, joined and sealed in an approved manner.
Exhaust equipment, including
fans and grease reservoirs, shall comply with Sections 506.5.1
through 506.5.5 and shall be of an approved design or shall be
listed for the application.
506.5.1 Exhaust fans. Exhaust fan housings serving a Type
I hood shall be constructed as required for grease ducts in
accordance with Section 506.3.1.1.
Exception; Fans listed and labeled in accordance with
UL 762.
506.5.1.1 Fan motor. Exhaust fan motors shall be
located outside of the exhaust airstream.
506.5.2 Exhaust fam discharge. Exhaust fans shall be
positioned so that the discharge will not impinge on the
roof, other equipment or appliances or parts of the struc-
ture. A vertical discharge fan shall be manufactured with
an approved drain outlet at the lowest point of the housing
to permit drainage of grease to an approved grease reser-
voir.
506.5.3 Exhaust fan mounting. An upblast fan shall be
hinged and supplied with a flexible weatherproof electrical
cable to permit inspection and cleaning. The ductwork shall
extend a minimum of 18 inches (457 mm) above the roof
surface.
506.5.4 Clearances. Exhaust equipment serving a Type I
hood shall have a clearance to combustible construction of
not less than 18 inches (457 mm).
Exceptioim: Factory-built exhaust equipment installed in
accordance with Section 304.1 and listed for a lesser
clearance.
506.5.5 Termination location. The outlet of exhaust equip-
ment serving Type I hoods shall be in accordance with Sec-
tion 506.3.12.
Exception: The minimum horizontal distance between
vertical discharge fans and parapet-type building struc-
tures shall be 2 feet (610 mm) provided that such struc-
tures are not higher than the top of the fan discharge
opening.
SECTDON 507
COiVIMERClAL KITCHEN HOODS
507.1 General. Commercial kitchen exhaust hoods shall com-
ply with the requirements of this section. Hoods shall be Type I
or Type II and shall be designed to capture and confine cooking
vapors and residues. Commercial kitchen exhaust hood sys-
tems shall operate during the cooking operation.
Exceptions:
1. Factory-built commercial exhaust hoods which are
tested in accordance with UL 710, listed, labeled and
installed in accordance with Section 304.1 shall not
be required to comply with Sections 507.4, 507.7,
507.11, 507.12, 507.13, 507.14 and 507.15.
2. Factory-built commercial cooking recirculating sys-
tems which are tested in accordance with UL 710B,
listed, labeled and installed in accordance with Sec-
tion 304.1 shall not be required to comply with Sec-
tions 507.4, 507.5, 507.7, 507.12, 507.13, 507.14 and
507.15.
3. Net exhaust volumes for hoods shall be permitted to
be reduced during no-load cooking conditions, where
engineered or listed multispeed or variable-speed
controls automatically operate the exhaust system to
maintain capture and removal of cooking effluents as
required by this section.
507.2 Where required. A Type I or Type II hood shall be
installed at or above all commercial cooking appliances in
accordance with Sections 507.2.1 and 507.2.2. Where any
cooking appliance under a single hood requires a Type I hood, a
Type I hood shall be installed. Where a Type II hood is
required, a Type I or Type II hood shall be installed.
507.2.1 Type I hoods. Type I hoods shall be installed where
cooking appliances produce grease or smoke, such as occurs
with griddles, fryers, broilers, ovens, ranges and wok ranges.
507.2.2 Type II hoods. Type II hoods shall be installed
where cooking or dishwashing appliances produce heat,
steam, or products of combustion and do not produce grease
or smoke, such as steamers, kettles, pasta cookers and
dishwashing machines.
Exceptions:
1. Under-counter-type commercial dishwashing
machines.
2. A Type 11 hood is not required for di shwashers and
potwashers that are provided with heat and water
vapor exhaust systems that are supplied by the
appliance manufacturer and are installed in accor-
dance with the manufacturer's instructions.
3. A single light-duty electric convection, bread,
retherm or microwave oven. The additional heat
and moisture loads generated by such appliances
shall be accounted for in the design of the HVAC
system.
4. A Type II hood is not required for the following
electrically heated appliances: toasters, steam
tables, popcorn poppers, hot dog cookers, coffee
makers, rice cookers, egg cookers, holding/warm-
ing ovens. The additional heat and moisture loads
generated by such appliances shall be accounted
for in the design of the HVAC system.
<
46
2007 OREGON MECHANICAL SPECIALTY CODE
EXHAUST SYSTEMS
507.2.3 Domestic cooking appliances used for commer-
cial purposes. Domestic cooking appliances utilized for
commercial purposes shall be provided with Type I or Type
II hoods as required for the type of appliances and processes
in accordance with Sections 507.2, 507.2.1 and 507.2.2.
507.2.4 Extra-heavy-duty. Type I hoods for use over
extra-heavy-duty cooking appliances shall not cover other
appliances that require fire extinguishing equipment and
such hoods shall discharge to aniexhaust system that is inde-
pendent of other exhaust systems.
507.3 Fuel-burning appliances.. Where vented fuel-burning
appliances are located in the same room or space as the hood,
provisions shall be made to prevent the hood system from inter-
fering with normal operation of the appliance vents.
507.4 Type I materials. Type I hoods shall be constructed of
steel not less than 0.043 inch (1.09 mm) (No. 1 8 MSG) in thick-
ness, or stainless steel not less than 0.037 inch (0.94 mm) (No.
20 MSG) in thickness.
507.5 l^pe II hood materials. Type II hoods shall be con-
structed of steelnot less than 0.030 inch (0.76 mm) (No. 22
Gage) in thickness, stainless steel not less than 0.024 inch (0.61
mm) (No. 24 Gage) in thickness, copper sheets weighing not
less than 24 ounces per square foot (7.3 kg/m^), or of other
approved material and gage.
507.6 Supports. Type I hoods shall be secured in place by non-
combustible supports. All Type I and Type II hood supports
shall be adequate for the applied load of the hood, the unsup-
ported ductwork, the effluent loading, and the possible weight
of personnel working in or on the hood.
507.7 Hood joints, seams and penetrations. Hood joints,
seams and penetrations shall comply with Sections 507.7.1 and
507.7.2.
507.7.1 Type I hoods. External hood joints, seams and pen-
etrations for Type I hoods shall be made with a continuous
external liquid-tight weld or braze to the lowest outermost
perimeter of the hood. Internal hood joints, seams, penetra-
tions, filter support frames, and other appendages attached
inside the hood shall not be required to be welded or brazed
but shall be otherwise sealed to be grease tight.
Exceptions:
1 . Penetrations shall not be required to be welded or
brazed where sealed by devices that are listed for
the application.
2. Internal welding or brazing of seams, joints, and
penetrations of the hood shall not be prohibited
provided that the joint is formed smooth or ground
so as to not trap grease, and is readily cleanable.
507.7.2 Type 11 hoods. Joints, seams and penetrations for
Type II hoods shall be constructed as set forth in Chapter 6,
shall be sealed on the interior of the hood and shall provide a
smooth surface that is readily cleanable and water tight.
507.8 Cleaning and grease gutters. A hood shall be designed
to provide for thorough cleaning of the entire hood. Grease gut-
ters shall drain to an approved collection receptacle that is fab-
ricated, designed and installed to allow access for cleaning.
507.9 Clearances for Type I hood. A Type I hood shall be
installed with a clearance to combustibles of not less than 18
inches (457 mm). This clearance may be reduced to 3 inches
(76 mm), provided the combustible material is protected with
materials as specified for 1-hour fire-resistive construction on
the hood side. Hoods less than 12 inches (305 mm) from the
ceiling or wall shall be flashed solidly with materials of the
thickness specified in Section 507.4 or materials conforming to
1-hour fire-resistive construction.
507.10 Hoods penetrating a ceiling. Type I hoods or portions
thereof penetrating a ceiling, wall or furred space shall comply
with all the requirements of Section 506.3. 10.
507.11 Grease filters. Type I hoods shall be equipped with
listed grease filters designed for the specific purpose.
Grease-collecting equipment shall be provided with access for
cleaning. The lowest edge of a grease filter located above the
cooking surface shall be not less than the height specified in
Table 507.11.
TABLE 507.11
MINIMUM DISTANCE BETWEEN THE LOWEST EDGE OF A
GREASE FILTER AND THE COOKING SURFACE OR THE
HEATING SURFACE
TYPE OF COOKING
APPLIANCES
HEIGHT ABOVE COOKING
SURFACE (feet)
Without exposed flame
0.5
Exposed fliame and burners
2
Exposed charcoal and charbroil type
3.5
For SI: 1 foot = 304.8 mm.
507.11.1 Criteria. Filters shall be of such size, type and
arrangement as will permit the required quantity of air to
pass through such units at rates not exceeding those for
which the filter or unit was designed or approved. Filter
units shall be installed in frames or holders so as to be
readily removable without the use of separate tools, unless
designed and installed to be cleaned in place and the system
is equipped for such cleaning in place. Removable filter
units shall be of a size that will allow them to be cleaned in a
dishwashing machine or pot sink. Filter units shall be
arranged in place or provided with drip-intercepting devices
to prevent grease or other condensate from dripping into
food or on food preparation surfaces.
507.11.2 Mounting position. Filters shall be installed at an
angle of not less than 45 degrees (0.79 rad) from the hori-
zontal and shall be equipped with a drip tray beneath the
lower edge of the filters.
507.12 Canopy size and location. The inside lower edge of
canopy-type Type I and II commercial hoods shall overhang or
extend a horizontal distance of not less than 6 inches (152 mm)
beyond the edge of the top horizontal surface of the appliance
on all open sides. The vertical distance between the front lower
lip of the hood and such surface shall not exceed 4 feet (1219
mm).
Exception: The hood shall be permitted to be flush with the
outer edge of the cooking surface where the hood is closed
to the appliance side by a noncombustible wall or panel.
<
2007 OREGON MECHANICAL SPECIALTY CODE
47
EXHAUST SYSTEMS
507.13 Capacity off Iioods. Commercial food service hoods
shall exhaust a minimum net quantity of air determined in
accordance with this section and Sections 507.13.1 through
507. 1 3.4. The net quantity of exhaust air shall be calculated by
subtracting any airflow supplied directly to a hood cavity from
the total exhaust flow rate of a hood. Where any combination of
heavy-duty, medium-duty and hght-duty cooking appliances
are utilized under a single hood, the exhaust rate required by
this section for the heaviest duty appliance covered by the hood
shall be used for the entire hood.
507.13«1 Extra-heavy-duty cooking appliaeces. The min-
imum net airflow for Type I hoods used for heavy-duty
cooking appliances shall be determined as follows:
Type of Hood ^^
Backshelf/pass-over
Double island canopy (per side)
Eyebrow
Single island canopy
Wall-mounted canopy
CFM per linear foot of hood
Not allowed
550
Not allowed
700
550
For SI: 1 cfm per linear foot = 1.55 L/s per linear meter
507.13.2 Meavy-duty cooking appliances. The minimum
net airflow for Type I hoods used for heavy-duty cooking
appliances shall be determined as follows:
Type of Hood
CFM per linear foot of hood
Backshelf/pass-over
400
Double island canopy (per side)
400
Eyebrow
Not allowed
Single island canopy
600
Wall-mounted canopy
400
For SI: 1 cfm per linear foot = 1.55 L/s per linear meter
507.13.3 Medium-duty cooking appliances. The mini-
mum net airflow for Type I hoods used for medium-duty
cooking appliances shall be determined as follows:
Type of Hood
CFM per linear foot of hood
Backshelf/pass-over
300
Double island canopy (per side)
300
Eyebrow
250
Single island canopy
500
Wall-mounted canopy
300
For SI: 1 cfm per linear foot = 1.55 L/s per linear meter
liances. The minimum
net airflow for Type I hoods used for light duty cooking
appliances and food service preparation and cooking opera-
tions approved for use under a Type II hood shall be deter-
mined as follows:
Type of Hood
CFM per linear foot of hood
Backshelf/pass-over
250
Double island canopy (per side)
250
Eyebrow
250
Single island canopy
400
Wall-mounted canopy
200
For SI: 1 cfm per linear foot = 1.55 L/s per linear meter
507.13.5 Dishwashing appliances. The minimum net air-
flow for Type II hoods used for dishwashing appliances
shall be 100 CFM per linear foot of hood length.
Exception: Dishwashing appliances and equipment
installed in accordance with Section 507.2.2, Exception
2.
507.14 Noncanopy size and location. Noncanopy-type hoods
shall be located a maximum of 3 feet (914 mm) above the cook-
ing surface. The edge of the hood shall be set back a maximum
of 1 foot (305 mm) from the edge of the cooking surface.
507.15 Exhaust outlets. Exhaust outlets located within the
hood shall be located so as to optimize the capture of particulate
matter. Each outlet shall serve not more than a 12-foot (3658
mm) section of hood.
507.16 Performance test. A performance test shall be con-
ducted upon completion and before final approval of the instal-
lation of a ventilation system serving commercial cooking
appliances. The test shall verify the rate of exhaust airflow
required by Section 507.13, makeup airflow required by Sec-
tion 508, and proper operation as specified in this chapter. The
permit holder shall furnish the necessary test equipment and
devices required to perform the tests.
507.16.1 Capture and containment test. The permit
holder shall verify capture and containment performance of
the exhaust system. This field test shall be conducted with
all appliances under the hooid at operating temperatures,
with all sources of outdoor air providing makeup air for the
hood operating and with all sources of recirculated air pro-
viding conditioning for the space in which the hood is
located operating. Capture and containment shall be veri-
fied visually by observing smoke or steam produced by
actual or simulated cooking, such as with smoke candles,
smoke puffers, etc.
SECTION 508
COMMERCIAL KITCHEN MAKEUP AIR
508.1 Makeup air. Makeup air shall be supplied during the
operation of commercial kitchen exhaust systems that are pro-
vided for commercial cooking appliances. The amount of
makeup air supplied shall be approximately equal to the
amount of exhaust air. The makeup air shall not reduce the
effectiveness of the exhaust system. Makeup air shall be pro-
vided by gravity or mechanical means or both. For mechanical
makeup air systems, the exhaust and makeup air systems shall
be electrically interlocked to insure that makeup air is provided
whenever the exhaust system is in operation. Makeup air intake
opening locations shall comply with Sections 401.4 and
401.4.1.
508.1.1 Makeup air temperature. The temperature differ-
ential between makeup air and the air in the conditioned
space shall not exceed 10°F (6°C).
Exceptions:
1 . Makeup air that is part of the air-conditioning sys-
tem.
2007 OREGON MECHANICAL SPECIALTY CODE
EXHAUST SYSTEMS
2. Makeup air that does not decrease the comfort con-
ditions of the occupied space.
508.2 Compensating hoods. Manufacturers of compensating
hoods shall provide a label indicating minimum exhaust flow
and/or maximum makeup airflow that provides capture and
containment of the exhaust effluent.
SECTION 509
FIRE SUPPRESSION SYSTEMS
509.1 Where required. Commercial cooking appliances
required by Section 507.2. 1 to have a Type I hood shall be pro-
vided with an approved automatic fire suppression system
complying with Sections 509.2 through 509.5.
509.2 Type of system. The automatic fire suppression system
shall be of a type recognized for protection of commercial
cooking appliance and exhaust systems of the type and
arrangement protected. Pre-engineered automatic dry- and
wet-chemical fire suppression systems shall be tested in accor-
dance with UL 300. Automatic fire suppression systems,
including pre-engineered and engineered dry- and wet-chemi-
cal fire-suppression systems, shall be listed and labeled for spe-
cific use as protection for commercial cooking operations and
shall be installed in accordance with Section 304. 1 . Automatic
fire suppression systems of the following types shall be
installed in accordance with the referenced standard indicated:
1. Carbon-dioxide extinguishing system, NFPA 12.
2. Automatic sprinkler system, NFPA 13.
3. Foam- water sprinkler system or foam-water spray sys-
tems, NFPA 16.
4. Dry -chemical extinguishing systems, NFPA 17.
5. Wet-chemical extinguishing systems, NFPA 17 A.
509.3 System actuation. Each automatic fire suppression sys-
tem shall have both automatic and manual actuation means. A
manual actuation device shall be located at or near a means of
egress from the cooking area, a minimum of 10 feet (3048 mm)
and a maximum of 20 feet (6096 mm) from the kitchen exhaust
system. The manual actuation device shall be located a mini-
mum of 4 feet 6 inches (1372 mm) and a maximum of 5 feet
(1524 mm) above the floor. The manual actuation shall require
a maximum force of 40 pounds (178 N) and a maximum move-
ment of 14 inches (356 mm) to actuate the fire suppression sys-
tem.
Exception: Automatic sprinkler systems shall not be
required to be equipped with manual actuation means.
509.4 System interconnection. The actuation of the automatic
fire suppression system shall automatically shut down the fuel
or electrical power supply to the cooking appliances. The fuel
and electrical power supply reset shall be manual.
509.5 System test and inspection. The automatic fire suppres-
sion system shall be acceptance-tested in accordance with the
fire prevention code and installation standard listed in Section
509.3 and with the manufacturer's instructions.
SECTION 510
HAZARDOUS EXHAUST SYSTEMS
510.1 General. This section shall govern the design and con-
struction of duct systems for hazardous exhaust and shall deter-
mine where such systems are required. Hazardous exhaust
systems are systems designed to capture and control hazardous
emissions generated from product handling or processes, and
convey those emissions to the outdoors. Hazardous emissions
include flammable vapors, gases, fumes, mists or dusts, and
volatile or airborne materials posing a health hazard, such as
toxic or corrosive materials. For the purposes of this section,
the health hazard rating of materials shall be as specified in
NFPA 704.
For the purposes of the provisions of Section 510, a labora-
tory shall be defined as a facility where the use of chemicals is
related to testing, analysis, teaching, research or developmen-
tal activities. Chemicals are used or synthesized on a non-pro-
duction basis, rather than in a manufacturing process.
510.2 Where required. A hazardous exhaust system shall be
required wherever operations involving the handling or pro-
cessing of hazardous materials, in the absence of such exhaust
systems and under normal operating conditions, have the
potential to create one of the following conditions:
1 . A flammable vapor, gas, fume, mist or dust is present in
concentrations exceeding 25 percent of the lower
flammability limit of the substance for the expected
room temperature.
2. A vapor, gas, fume, mist or dust with a health-hazard rat-
ing of 4 is present in any concentration.
3 . A vapor, gas, fume, mist or dust with a health-hazard rat-
ing of 1 , 2 or 3 is present in concentrations exceeding 1
percent of the median lethal concentration of the sub-
stance for acute inhalation toxicity.
Exception: Laboratories, as defined in Section 510.1,
except where the concentrations listed in Item 1 are
exceeded or a vapor, gas, fume, mist or dust with a
health-hazard rating of 1, 2, 3 or 4 is present in concentra-
tions exceeding 1 percent of the median lethal concentration
of the substance for acute inhalation toxicity.
510.2.1 Lumber yards and woodworking facilities.
Equipment or machineiy located inside buildings at lumber
yards and woodworking facilities which generates or emits
combustible dust shall be provided with an approved
dust-collection and exhaust system installed in confor-
mance with this section and the Fire Code. Equipment and
systems that are used to collect, process or convey combus-
tible dusts shall be provided with an approved explo-
sion-control system.
510.2.2 Combustible fibers. Equipment or machinery
within a building which generates or emits combustible
fibers shall be provided with an approved dust-collecting
and exhaust system. Such systems shall comply with this
code and the Fire Code.
510.3 Design and operation. The design and operation of the
exhaust system shall be such that flammable contaminants are
diluted in noncontaminated air to maintain concentrations in
2007 OREGON MECHANICAL SPECIALTY CODE
49
EXHAUST SYSTEEViS
the exhaust flow below 25 percent of the contaminant's lower
flammability limit.
510.4 Independent system. Hazardous exhaust systems shall
be independent of other types of exhaust systems. Incompati-
ble materials, as defined in the Fire Code, shall not be
exhausted through the same hazardous exhaust system. Haz-
ardous exhaust systems shall not share common shafts with
other duct systems, except where such systems are hazardous
exhaust systems originating in the same fire area.
Exception: The provision of this section shall not apply to
laboratory exhaust systems where all of the following con-
ditions apply:
1 . All of the hazardous exhaust ductwork and other labo-
ratory exhaust within both the occupied space and the
shafts is under negative pressure while in operation.
2. The hazardous exhaust ductwork manifolded
together within the occupied space must originate
within the same fire area.
3. Each control branch has a flow regulating device.
4. Perchloric acid hoods and connected exhaust shall be
prohibited from manifolding.
5. Radioisotope hoods are equipped with filtration
and/or carbon beds where required by the registered
design professional.
6. Biological safety cabinets are filtered.
7. Provision is made for continuous maintenance of
negative static pressure in the ductwork.
Contaminated air shall not be recirculated to occupied areas
unless the contaminants have been removed. Air contaminated
with explosive or flammable vapors, fumes or dusts; flamma-
ble, highly toxic or toxic gases; or radioactive material shall not
be recirculated.
510.5 Design. Systems for removal of vapors, gases and smoke
shall be designed by the constant velocity or equal friction
methods. Systems conveying particulate matter shall be
designed employing the constant velocity method.
510.5.1 Balancing. Systems conveying explosive or radio-
active materials shall be prebalanced by duct sizing. Other
systems shall be balanced by duct sizing with balancing
devices, such as dampers. Dampers provided to balance
air-flow shall be provided with securely fixed mini-
mum-position blocking devices to prevent restricting flow
below the required volume or velocity.
510.5.2 Emission control. The design of the system shall
be such that the emissions are confined to the area in which
they are generated by air currents, hoods or enclosures and
shall be exhausted by a duct system to a safe location or
treated by removing contaminants.
510.5.3 Hoods required. Hoods or enclosures shall be used
where contaminants originate in a limited area of a space. The
design of the hood or enclosure shall be such that air currents
created by the exhaust systems will capture the contaminants
and transport them directly to the exhaust duct.
510.5.4 Contaminant capture and dilution. The velocity
and circulation of air in work areas shall be such that con-
taminants are captured by an airstream at the area where the
emissions are generated and conveyed into a product-con-
veying duct system. Contaminated air from work areas
where hazardous contaminants are generated shall be
diluted below the thresholds specified in Section 5 10.2 with
air that does not contain other hazardous contaminants.
510.5.5 Makeup air. Makeup air shall be provided at a rate
approximately equal to the rate that air is exhausted by the
hazardous exhaust system. Makeup-air intakes shall be
located so as to avoid recirculation of contaminated air.
510.5.6 Clearances. The minimum clearance between
hoods and combustible construction shall be the clearance
required by the duct system.
510.5.7 Ducts. Hazardous exhaust duct systems shall
extend directly to the exterior of the building and shall not
extend into or through ducts and plenums.
510.6 Penetrations. Penetrations of structural elements by a
hazardous exhaust system shall conform to Sections 510.6.1
through 510.6.4.
tion: Duct penetrations within H-5 occupancies as
allowed by the Building Code.
510.6.1 Fire dampers. Fire dampers are prohibited in haz-
ardous exhaust ducts.
510.6.2 Floors. Hazardous exhaust systems that penetrate a
floor/ceiling assembly shall be enclosed in a fire-resis-
tance-rated shaft constructed in accordance with the Build-
ing Code.
assemblies. Hazardous exhaust duct systems
that penetrate fire-resistance-rated wall assemblies shall be
enclosed in fire-resistance-rated construction from the point
of penetration to the outlet terminal, except where the inte-
rior of the duct is equipped with an approved automatic fire
suppression system. Ducts shall be enclosed in accordance
with the Building Code requirements for shaft construction
and such enclosure shall have a minimum fire-resis-
tance-rating of not less than the highest fire-resistance-rated
wall assembly penetrated.
510.6.4 Fire walls. Ducts shall not penetrate a fire wall.
510.7 Suppression required. Ducts shall be protected with an
approved automatic fire suppression system installed in accor-
dance with the Building Code.
1 . An approved automatic fire suppression system shall
not be required in ducts conveying materials, fumes,
mists and vapors that are nonflammable and
noncombustible under all conditions and at any con-
centrations.
2. An approved automatic fire suppression system shall
not be required in ducts where the largest cross-sec-
tional diameter of the duct is less than 10 inches (254
mm).
3. For laboratories, as defined in Section 510.1, auto-
matic fire protection systems shall not be required in
laboratory hoods or exhaust systems.
50
2007 OREGOtM SWECHANICAL SPECIALTY CODE
EXHAUST SYSTEMS
510.8 Duct construction. Ducts utilized to convey hazardous
exhaust shall be constructed of approved G90 galvanized sheet
steel, with a minimum nominal thickness as specified in Table
510.8.
510.9 Supports. Ducts shall be supported at intervals not
exceeding 10 feet (3048 mm). Supports shall be constructed of
noncombustible material.
Nonmetallic ducts utilized in systems exhausting nonflam-
mable corrosive fumes or vapors shall be listed and labeled.
Nonmetallic duct shall have a flame spread index of 25 or less
and a smoke-developed index of 50 or less, when tested in
accordance with ASTM E 84. Ducts shall be approved for
installation in such an exhaust system.
Where the products being exhausted are detrimental to the
duct material, the ducts shall be constructed of alternative
materials that are compatible with the exhaust.
TABLE 510.8
MINIMUM DUCT THICKNESS
DIAMETER OF
DUCT OR
MAXIMUM SIDE
DIMENSION
MINIMUM NOMINAL THICKNESS
Nonabrasive
materials
Nonabrasive/
Abrasive
materials
Abrasive
materials
0-8 inches
0.028 inch
(No. 24 Gage)
0.034 inch
(No. 22 Gage)
0.040 inch
(No. 20 Gage)
9-18 inches
0.034 inch
(No. 22 Gage)
, 0.040 inch
(No. 20 Gage)
0.052 inch
(No. 18 Gage)
19-30 inches
0.040 inch
(No. 20 Gage)
0.052 inch
(No. 18 Gage)
0.064 inch
(No. 16 Gage)
Over 30 inches
0.052 inch
(No. 18 Gage)
0.064 inch
(No. 16 Gage)
0.079 inch
(No. 14 Gage)
For SI: 1 inch = 25.4 mm.
510.8.1 Duct joints. Ducts shall be made tight with lap
joints having a minimum lap of 1 inch (25 mm).
510.8.2 Clearance to combustibles. Ducts shall have a
clearance to combustibles in accordance with Table 5 10.8.2.
Exhaust gases having temperatures in excess of 600°F
(3 16°C) shall be exhausted to a chimney in accordance with
Section 51 1.2.
TABLE 510.8.2
CLEARANCE TO COMBUSTIBLES
TYPE OF EXHAUST OR
TEMPERATURE OF EXHAUST (°F)
CLEARANCE TO COMBUSTIBLES
(inches)
Less than 100
1
100-600
12
Flammable vapors
6
For SI: 1 inch = 25.4 mm, °C = [(T)- 32]/1.8.
510.8.3 Explosion relief. Systems exhausting potentially
explosive mixtures shall be protected with an approved
explosion relief system or by an approved explosion preven-
tion system designed and installed in accordance with NFPA
69. An explosion relief system shall be designed to minimize
the structural and mechanical damage resulting from an
explosion or deflagration within the exhaust system. An
explosion prevention system shall be designed to prevent an
explosion or deflagration from occurring.
SECTION 511
DUST, STOCK AND REFUSE
CONVEYING SYSTEMS
511.1 Dust, stock and refuse conveying systems. Dust, stock
and refuse conveying systems shall comply with the provisions
of Section 510 and Sections 511.1.1 through 511.2.
511.1.1 Collectors and separators. Collectors and separa-
tors involving such systems as centrifugal separators, bag
filter systems and similar devices, and associated supports
shall be constructed of noncombustible materials and shall
be located on the exterior of the building or structure. A col-
lector or separator shall not be located nearer than 10 feet
(3048 mm) to combustible construction or to an unprotected
wall or floor opening, unless the collector is provided with a
metal vent pipe that extends above the highest part of any
roof with a distance of 30 feet (9144 mm).
Exceptions:
1. Collectors such as "Point of Use" collectors, close
extraction weld fume collectors, spray finishing
booths, stationary grinding tables, sanding booths,
and integrated or machine-mounted collectors
shall be permitted to be installed indoors provided
the installation is in accordance with the Fire Code
and the Electrical Code.
2. Collectors in independent exhaust systems han-
dling combustible dusts shall be permitted to be
installed indoors provided that such collectors are
installed in compliance with the Fire Code and the
Electrical Code.
511.1.2 Discharge pipe. Discharge piping shall conform to
the requirements for ducts, including clearances required
for high-heat appliances, as contained in this code. A deliv-
ery pipe from a cyclone collector shall not convey refuse
directly into the firebox of a boiler, furnace, dutch oven,
refuse burner, incinerator or other appliance.
511.1.3 Conveying systems exhaust discharge. An
exhaust system shall discharge to the outside of the building
either directly by flue or indirectly through the bin or vault
into which the system discharges except where the contami-
nants have been removed. Exhaust system discharge shall
be permitted to be recirculated provided that the solid par-
ticulate has been removed at a minimum efficiency of 99.9
percent at 10 microns, vapor concentrations are less than 25
percent of the LFL, and approved equipment is used to mon-
itor the vapor concentration.
511.1.4 Spark protection. The outlet of an open-air
exhaust terminal shall be protected with an approved metal
or other noncombustible screen to prevent the entry of
sparks.
511.1.5 Explosion relief vents. A safety or explosion relief
vent shall be provided on all systems that convey combusti-
2007 OREGON MECHANICAL SPECIALTY CODE
51
EXHAUST SYSTEMS
ble refuse or stock of an explosive nature, in accordance
with the requirements of the Building Code.
511.1.5.1 Screens. Where a screen is installed in a safety
relief vent, the screen shall be attached so as to permit
ready release under the explosion pressure.
511.1.5.2 Hoods. The relief vent shall be provided with
an approved noncombustible cowl or hood, or with a
counterbalanced relief valve or cover arranged to prevent
the escape of hazardous materials, gases or liquids.
511.2 Exhauslt oetlets. Outlets for exhaust that exceed 600°F
(315°C) shall be designed as a chimney in accordance with
Table 511.2.
SECTION 512
SUBSLAB SOIL EXHAUST SYSTEMS
512.1 GenieraL When a subslab soil exhaust system is pro-
vided, the duct shall conform to the requirements of this sec-
tion.
512.2 Materials. Subslab soil exhaust system duct material
shall be air duct material listed and labeled to the requirements
of UL 181 for Class air ducts, or any of the following piping
materials that comply with the Plumbing Code as building san-
itary drainage and vent pipe: cast iron; galvanized steel; brass
or copper pipe; copper tube of a weight not less than that of
copper drainage tube. Type DWV; and plastic piping.
512.3 Grade. Exhaust system ducts shall not be trapped and
shall have a minimum slope of one-eighth unit vertical in 12
units horizontal (1 -percent slope).
512.4 Terminatiom. Subslab soil exhaust system ducts shall
extend through the roof and terminate at least 6 inches (152
mm) above the roof and at least 10 feet (3048 mm) from any
operable openings or air intake.
512.5 Identification. Subslab soil exhaust ducts shall be per-
manently identified within each floor level by means of a tag,
stencil or other approved marking.
SECTION 513
SMOKE CONTROL SYSTEMS
513.1 Scope and purpose. This section applies to mechanical
and passive smoke control systems that are required by the
Building Code. The purpose of this section is to establish mini-
mum requirements for the design, installation and acceptance
testing of smoke control systems that are intended to provide a
tenable environment for the evacuation or relocation of occu-
pants. These provisions are not intended for the preservation of
contents, the timely restoration of operations, or for assistance
in fire suppression or overhaul activities. Smoke control sys-
tems regulated by this section serve a different purpose than the
smoke- and heat- venting provisions found in Section 910 of the
Building Code.
513.2 General design requirements. Buildings, structures, or
parts thereof required by this code to have a smoke control sys-
tem or systems shall have such systems designed in accordance
with the applicable requirements of Section 909 of the Building
Code and the generally accepted and well-established princi-
ples of engineering relevant to the design. The construction
documents shall include sufficient information and detail to
describe adequately the elements of the design necessary for
the proper implementation of the smoke control systems.
These documents shall be accompanied with sufficient infor-
mation and analysis to demonstrate compliance with these pro-
visions.
TABLE 511.2
CONSTRUCTBON, CLEARANCE AND TERMINATION REQUIREMENTS FOR
SINGLE-WALL METAL CHIMNEYS
CHIiVlNEYS
SERVING
MINIMUM THICKNESS
TERMINATION
CLEARANCE
Walls
(inch)
Lining
Above roof
opening
(feet)
Above any part of
building within (feet)
Combustible
construction
(inches)
Noncombustible
construction
10
25
50
Interior
inst.
Exterior
inst.
Interior
inst.
Exterior
inst.
High-heat apphances
(Over 2,000°F)^
0.127
(No. 10
MSG)
4V2"laidon4V2"bed
20
—
—
20
See Note c
Low Heat appliances
(1,000°F normal operation)
0.127
(No. 10 MSG)
none
3
2
—
—
18
6
Up to 18" diameter. 2"
Medium-heat appliances
(2,000°F maximum)''
0.127
(No. 10 MSG)
Uptol8"dia.— 2'/2"
Over 18"-4V2"
On 4'//' bed
10
—
10
—
36
24
Over 18" d
iameter, 4"
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm,°C = [(°F)-32]/1.8.
a. Lining shall extend from bottom to top of outlet.
b. Lining shall extend from 24 inches below connector to 24 feet above.
c. Clearance shall be as specified by the design engineer and shall have sufficient clearance from buildings and structures to avoid overheating combustible materials
(maximum 160''F).
52
2007 OREGON MECHANICAL SPECIALTY CODE
EXHAUST SYSTEMS
513.3 Special inspection and test requirements. In addition
to the ordinary inspection and test requirements which build-
ings, structures and parts thereof are required to undergo,
smoke control systems subject to the provisions of Section 909
of the Building Code shall undergo special inspections and
tests sufficient to verify the proper commissioning of the
smoke control design in its final installed condition. The design
submission accompanying the construction documents shall
clearly detail procedures and methods to be used and the items
subject to such inspections and tests. Such commissioning
shall be in accordance with generally accepted engineering
practice and, where possible, based on published standards for
the particular testing involved. The special inspections and
tests required by this section shall be conducted under the same
terms as found in Section 1704 of the Building Code.
513.4 Analysis. A rational analysis supporting the types of
smoke control systems to be employed, their methods of opera-
tion, the systems supporting them; and the methods of con-
struction to be utilized shall accompany the submitted
construction documents and shall ihclude, but not be limited to,
the items indicated in Sections 513,4.1 through 513.4.6.
513.4.1 Stack effect. The system shall be designed such
that the maximum probable normal or reverse stack effects
will not adversely interfere with the system's capabilities. In
determining the maximum probjable stack effects, altitude,
elevation, weather history and interior temperatures shall be
used.
513.4.2 Temperature effect of fire. Buoyancy and expan-
sion caused by the design fire in accordance with Section
513.9 shall be analyzed. The system shall be designed such
that these effects do not adversely interfere with its capabili-
ties.
513.4.3 Wind effect. The design shall consider the adverse
effects of wind. Such consideration shall be consistent with
the wind-loading provisions of the Building Code.
513.4.4 HVAC systems. The design shall consider the
effects of the heating, ventilating and air-conditioning
(HVAC) systems on both smoke and fire transport. The
analysis shall include all permutations of systems' status.
The design shall consider the effects of fire on the HVAC
systems.
513.4.5 Climate. The design shall consider the effects of
low temperatures on systems, property and occupants. Air
inlets and exhausts shall be located so as to prevent snow or
ice blockage.
513.4.6 Duration of operation. All portions of active or
passive smoke control systems shall be capable of continued
operation after detection of the fire event for a period of not
less than either 20 minutes or 1.5 times the calculated egress
time, whichever is less.
513.5 Smoke barrier construction. Smoke barriers shall
comply with the Building Code. Smoke barriers shall be con-
structed and sealed to limit leakage areas exclusive of protected
openings. The maximum allowable leakage area shall be the
aggregate area calculated using the following leakage area
ratios:
I.Walls:
AM,., = 0.00100
2. Exit enclosures: AIA^. = 0.00035
3. All other shafts: A/A^ = 0.00150
4. Floors and roofs : A/A^ = 0.00050
where:
A = Total leakage area, square feet (m^).
Ap = Unit floor or roof area of barrier, square feet (m^).
A^ = Unit wall area of barrier, square feet (m^).
The leakage area ratios shown do not include openings due
to doors, operable windows or similar gaps. These shall be
included in calculating the total leakage area.
513.5.1 Leakage area. Total leakage area of the barrier is
the product of the smoke barrier gross area times the allow-
able leakage area ratio, plus the area of other openings such
as gaps and operable windows. Compliance shall be deter-
mined by achieving the minimum air pressure difference
across the barrier with the system in the smoke control mode
for mechanical smoke control systems. Passive smoke con-
trol systems tested using other approved means such as door
fan testing shall be as approved by the code official.
513.5.2 Opening protection. Openings in smoke barriers
shall be protected by automatic-closing devices actuated by
the required controls for the mechanical smoke control sys-
tem. Door openings shall be protected by door assemblies
complying with the requirements of the Building Code for
doors in smoke barriers.
Exceptions:
1. Passive smoke control systems with auto-
matic-closing devices actuated by spot-type
smoke detectors listed for releasing service
installed in accordance with the Building Code.
2. Fixed openings between smoke zones which are
protected utilizing the airflow method.
3. In Group 1-2 where such doors are installed across
corridors, a pair of opposite-swinging doors with-
out a center mullion shall be installed having
vision panels with approved fire-rated glazing
materials in approved fire -rated frames, the area of
which shall not exceed that tested. The doors shall
be close-fitting within operational tolerances, and
shall not have undercuts, louvers or grilles. The
doors shall have head and jamb stops, astragals or
rabbets at meeting edges and automatic-closing
devices. Positive latching devices are not required.
4. Group 1-3.
5. Openings between smoke zones with clear ceiling
heights of 14 feet (4267 mm) or greater and bank
down capacity of greater than 20 minutes as deter-
mined by the design fire size.
513.5.2.1 Ducts and air transfer openings. Ducts and
air transfer openings are required to be protected with a
minimum Class II, 250°F (121°C) smoke damper com-
plying with the Building Code.
513.6 Pressurization method. The primary mechanical
means of controlling smoke shall be by pressure differences
2007 OREGON MECHANICAL SPECIALTY CODE
53
EXHAUST SYSTEMS
across smoke barriers. Maintenance of a tenable environment
is not required in the smoke control zone of fire origin.
513.6.1 Mmiinum pressure difference. The minimum
pressure difference across a smoke barrier shall be
0.05-inch water gage (12.4 Pa) in fully sprinklered build-
ings.
In buildings permitted to be other than fully sprinklered,
the smoke control system shall be designed to achieve pres-
sure differences at least two times the maximum calculated
pressure difference produced by the design fire.
513.6.2 Maximum pressure difference. The maximum air
pressure difference across a smoke barrier shall be deter-
mined by required door-opening or closing forces. The
actual force required to open exit doors when the system is
in the smoke control mode shall be in accordance with the
Building Code. Opening and closing forces for other doors
shall be determined by standard engineering methods for
the resolution of forces and reactions. The calculated force
to set a side -hinged, swinging door in motion shall be deter-
mined by:
F = F^,+KiWAAP)f2(W-d) (Equation 5-2)
where:
A = Door area, square feet (m^).
d = Distance from door handle to latch edge of door, feet
(m).
F = Total door opening force, pounds (N).
F^^ = Force required to overcome closing device, pounds
(N).
K = Coefficient 5.2 (1.0).
W = Door width, feet (m).
AP = Design pressure difference, inches (Pa) water gage.
513.7 Airflow design method. When approved by the code
official, smoke migration through openings fixed in a perma-
nently open position, which are located between smoke control
zones by the use of the airflow method, shall be permitted. The
design airflows shall be in accordance with this section. Air-
flow shall be directed to limit smoke migration from the fire
zone. The geometry of openings shall be considered to prevent
flow reversal from turbulent effects.
513.7.1 Velocity. The minimum average velocity through a
fixed opening shall not be less than:
v = 217.2[h (Tf- T,)/(Tj+ 460)] "^ (Equation 5-3)
For SI: V = 1 19.9 [h (Tf - T,)IT^"^
where:
H = Height of opening, feet (m).
7} = Temperature of smoke, °F (K).
Tg = Temperature of ambient air, °F (K).
V = Air velocity, feet per minute (m/minute).
513.7.2 Prohibited conditions. This method shall not be
employed where either the quantity of air or the velocity of
the airflow will adversely affect other portions of the smoke
control system, unduly intensify the fire, disrupt plume
dynamics or interfere with exiting. In no case shall airflow
toward the fire exceed 200 feet per minute (1.02 m/s).
Where the formula in Section 513.7.1 requires airflow to
exceed this limit, the airflow method shall not be used.
513.8 Exhaust method. When approved by the building offi-
cial, mechanical smoke control for large enclosed volumes,
such as in atriums or malls, shall be permitted to utilize the
exhaust method. Smoke control systems using the exhaust
method shall be designed in accordance with NFPA 92B.
513.8.1 Exhaust rate. The height of the lowest horizontal
surface of the accumulating smoke layer shall be maintained
at least 6 feet (1829 mm) above any walking surface which
forms a portion of a required egress system within the
smoke zone.
513.9 Design fire. The design fire shall be based on a rational
analysis performed by the registered design professional and
approved by the code official. The design fire shall be based on
the analysis in accordance with Section 5 1 3.4 and this section.
513.9.1 Factors considered. The engineering analysis shall
include the characteristics of the fuel, fuel load, effects
included by the fire, and whether the fire is likely to be
steady or unsteady.
- 513.9.2 Design fire fuel. Determination of the design fire
shall include consideration of the type of fuel, fuel spacing
and configuration.
513.9.3 Heat-release assumptions. The analysis shall
make use of the best available data from approved sources
and shall not be based on excessively stringent limitations of
combustible material.
513.9.4 Sprinkler effectiveness assumptions. A docu-
mented engineering analysis shall be provided for condi-
tions that assume fire growth is halted at the time of
sprinkler activation.
513.10 Equipment. Equipment such as, but not hrnited to,
fans, ducts, automatic dampers and balance dampers shall be
suitable for their intended use, suitable for the probable expo-
sure temperatures that the rational analysis indicates, and as
approved by the code official.
513.10.1 Exhaust fans. Components of exhaust fmis shall
be rated and certified by the manufacturer for the probable
temperature rise to which the components will be exposed.
This temperature rise shall be computed by:
T, = (QJmc) + (TJ (Equation 5-4)
where:
c = Specific heat of smoke at smoke-layer temperature,
Btu/lb°F (kJ/kg X K). .
m = Exhaust rate, pounds per second (kg/s).
Q^ = Convective heat output of fire, Btu/s (kW).
T ^ = Ambient temperature, °F (K).
r J = Smoke temperature, °F (K).
Exception: Reduced T^ as calculated based on the assur-
ance of adequate dilution air.
54
2007 OREGON MECHANICAL SPECIALTY CODE
EXHAUST SYSTEMS
513.10.2 Ducts. Duct materials and joints shall be capable
of withstanding the probable temperatures and pressures to
which they are exposed as determined in accordance with
Section 513.10.1. Ducts shall be constructed and supported
in accordance with Chapter 6. Ducts shall be leak tested to
1 .5 times the maximum design pressure in accordance with
nationally accepted practices. Measured leakage shall not
exceed 5 percent of design flow. Results of such testing shall
be a part of the documentation procedure. Ducts shall be
supported directly from fire-resistance-rated structural ele-
ments of the building by substantial, noncombustible sup-
ports.
Exception: Flexible connections, for the purpose of
vibration isolation, that are constructed of approved
fire-resistance-rated materials.
513.10.3 Equipment, inlets and outlets. Equipment shall
be located so as to not expose uninvolved portions of the
building to an additional fire hazard. Outdoor air inlets shall
be located so as to minimize the potential for introducing
smoke or flame into the building. Exhaust outlets shall be so
located as to minimize reintroduction of smoke into the
building and to limit exposure of the building or adjacent
buildings to an additional fire hazard.
513.10.4 Automatic dampers. Automatic dampers,
regardless of the purpose for which they are installed within
the smoke control system, shaU be listed and conform to the
requirements of approved recognized standards.
513.10.5 Fans. In addition to other requirements,
belt-driven fans shall have 1.5 times the number of belts
required for the design duty with the minimum number of
belts being two. Fans shall be selected for stable perfor-
mance based on normal temperature and, where applicable,
elevated temperature. Calculations and manufacturer's fan
curves shall be part of the documentation procedures. Fans
shall be supported and restrained by noncombustible
devices in accordance with the structural design require-
ments of the Building Code. Motors driving fans shall not be
operating beyond their nameplate horsepower (kilowatts) as
determined from measurement of actual current draw.
Motors driving fans shall have a minimum service factor of
1.15.
513.11 Power systems. The smoke control system shall be
supplied with two sources of power. Primary power shall be the
normal building power systems. Secondary power shall be
from an approved standby source complying with the Electri-
cal Code. The standby power source and its transfer switches
shall be in a separate room from the normal power transformers
and switch gear and shall be enclosed in a room constructed of
not less than 1-hour fire-resistance-rated fire barriers, venti-
lated directly to and from the exterior. Power distribution from
the two sources shall be by independent routes. Transfer to full
standby power shall be automatic and within 60 seconds of fail-
ure of the primary power. The systems shall comply with the
Electrical Code.
513.11.1 Power sources and power surges. Elements of
the smoke management system relying on volatile memo-
ries or the like shall be supplied with uninterruptible power
sources of sufficient duration to span 15-minute primary
power interruption. Elements of the smoke management
system susceptible to power surges shall be suitably pro-
tected by conditioners, suppressors or other approved
means.
513.12 Detection and control systems. Fire detection systems
providing control input or output signals to mechanical smoke
control systems or elements thereof shall comply with the
requirements of Chapter 9 of the Building Code and NFPA 72.
Such systems shall be equipped with a control unit complying
with UL 864 and listed as smoke control equipment.
Control systems for mechanical smoke control systems shall
include provisions for verification. Verification shall include
positive confirmation of actuation, testing, manual override,
the presence of power downstream of all disconnects and,
through a preprogrammed weekly test sequence report, abnor-
mal conditions audibly, visually and by printed report.
513.12.1 Wiring. In addition to meeting the requirements
of the Electrical Code, all wiring, regardless of voltage,
shall be fully enclosed within continuous raceways.
513.12.2 Activation. Smoke control systems shall be acti-
vated in accordance with the Building Code.
513.12.3 Automatic control. Where completely automatic
control is required or used, the automatic control sequences
shall be initiated from an appropriately zoned automatic
sprinkler system complying with Section 903.3.1.1 of the
Fire Code or from manual controls that are readily accessi-
ble to the fire department, and any smoke detectors required
by engineering analysis.
513.13 Control-air tubing. Control-air tubing shall be of suf-
ficient size to meet the required response times. Tubing shall be
flushed clean and dry prior to final connections. Tubing shall
be adequately supported and protected from damage. Tubing
passing through concrete or masonry shall be sleeved and pro-
tected from abrasion and electrolytic action.
513.13.1 Materials. Control-air tubing shall be hard-drawn
copper. Type L, ACR in accordance with ASTM B 42,
ASTM B 43, ASTM B 68, ASTM B 88, ASTM B 251 and
ASTM B 280. Fittings shall be wrought copper or brass, sol-
der type in accordance with ASME B 16.18 or ASME B
16.22. Changes in direction shall be made with appropriate
tool bends. Brass compression-type fittings shall be used at
final connection to devices; other joints shall be brazed
using a BCuP5 brazing alloy with solidus above 1,100°F
(593°C) and liquids below 1,500°F (816°C). Brazing flux
shall be used on copper-to-brass joints only.
Exception: Nonmetallic tubing used within control pan-
els and at the final connection to devices provided all of
the following conditions are met:
1 . Tubing shall be listed by an approved agency for
flame and smoke characteristics.
2. Tubing and connected device shall be completely
enclosed within a galvanized or paint-grade steel
enclosure of not less than 0.030 inch (0.76 mm)
(No. 22 galvanized sheet gage) thickness. Entry to
the enclosure shall be by copper tubing with a pro-
2007 OREGON MECHANICAL SPECIALTY CODE
55
EXHAUST SYSTEMS
tective grommet of neoprene or teflon or by suit-
able brass compression to male barbed adapter.
3. Tubing shall be identified by appropriately docu-
mented coding.
4. Tubing shall be neatly tied and supported within
the enclosure. Tubing bridging cabinets and doors
or moveable devices shall be of sufficient length to
avoid tension and excessive stress. Tubing shall be
protected against abrasion. Tubing serving
devices on doors shall be fastened along hinges.
513.13.2 Isolatioim from other ftmctloes. Control tubing
serving other than smoke control functions shall be isolated
by automatic isolation valves or shall be an independent
system.
513.13.3 Testimg. Test control-air tubing at three times the
operating pressure for not less than 30 minutes without any
noticeable loss in gauge pressure prior to final connection to
devices.
The detection and con-
trol systems shall be clearly marked at all junctions, accesses
and terminations.
513.15 Comtroil diagrams. Identical control diagrams shall be
provided and maintained as required by the Fire Code.
513.16 Fire ISghter's smoke control panel. A fire fighter's
smoke control panel for fire department emergency response
purposes only shall be provided in accordance with the Fire
Code.
513.17 System response time. Smoke control system activa-
tion shall comply with the Fire Code.
513.18 Acceptance testing. Devices, equipment, components
and sequences shall be tested in accordance with the Fire Code.
513.19 System acceptance. Acceptance of the smoke control
system shall be in accordance with the Fire Code.
514.1 General, Energy recovery ventilation systems shall be
installed in accordance with this section. Where required for
purposes of energy conservation, energy recovery ventilation
systems shall also comply with the Building Code.
514.2 Proliiilbited applications. Energy recovery ventilation
systems shall not be used in the following systems:
1. Hazardous exhaust systems covered in Section 510.
2. Dust, stock and refuse systems that convey explosive or
flammable vapors, fumes or dust.
3. Smoke control systems covered in Section 513.
4. Commercial kitchen exhaust systems serving Type I and
Type II hoods.
5. Clothes dryer exhaust systems covered in Section 504.
514.3 Access. A means of access shall be provided to the heat
exchanger and other components of the system as required for
service, maintenance, repair or replacement.
56
2007 OREGON MECHANICAL SPECIALTY CODE
CHAPTER 6
DUCT SYSTEMS
SECTION 601
GENERAL
601.1 Scope. Duct systems used for the movement of air in
air-conditioning, heating, ventilating and exhaust systems shall
conform to the provisions of this chapter except as otherwise
specified in Chapters 5 and 7.
Exception: Ducts discharging combustible material
directly into any combustion chamber shall conform to the
requirements of NFPA 82.
601.2 Air movement in egress elements. Corridors shall not
serve as supply, return, exhaust, relief or ventilation air ducts.
Exceptions:
1 . Use of a corridor as a source of makeup air for exhaust
systems in rooms that open directly onto such corri-
dors, including toilet rooms, bathrooms, dressing
rooms, smoking lounges and janitor closets, shall be
permitted, provided that each such corridor is directly
supplied with outdoor air at a rate greater than the rate
of makeup air taken from the corridor.
2. Where located within a dwelling unit, the use of corri-
dors for conveying return air shall not be prohibited.
3. Where located within tenant spaces of 1,000 square
feet (93 m^) or less in area, utilization of corridors for
conveying return air is permitted.
601.2.1 Corridor ceiling. Use of the space between the cor-
ridor ceiling and the floor or roof structure above as a return
air plenum is permitted for one or more of the following
conditions:
1. The corridor is not required to be of fire-resis-
tance-rated construction;
2. The corridor is separated from the plenum by
fire-resistance-rated construction;
3. The air-handling system serving the corridor is shut
down upon activation of the air-handling unit smoke
detectors required by this code;
4. The air-handling system serving the corridor is shut
down upon detection of sprinkler waterflow where
the building is equipped throughout with an auto-
matic sprinkler system; or
5. The space between the corridor ceiling and the floor
or roof structure above the corridor is used as a com-
ponent of an approved engineered smoke control sys-
tem.
601.3 Exits. Equipment and ductwork for exit enclosure venti-
lation shall comply with one of the following items:
1 . Such equipment and ductwork shall be located exte-
rior to the building and shall be directly connected to
the exit enclosure by ductwork enclosed in construc-
tion as required by the Building Code for shafts.
2. Where such equipment and ductwork is located
within the exit enclosure, the intake air shall be taken
directly from the outdoors and the exhaust air shall be
discharged directly to the outdoors, or such air shall
be conveyed through ducts enclosed in construction
as required by the Building Code for shafts.
3. Where located within the building, such equipment
and ductwork shall be separated from the remainder
of the building, including other mechanical equip-
ment, with construction as required by the Building
Code for shafts.
In each case, openings into fire-resistance-rated construc-
tion shall be limited to those needed for maintenance and oper-
ation and shall be protected by self-closing fire-
resistance-rated devices in accordance with the Building Code
for enclosure wall opening protectives. Exit enclosure ventila-
tion systems shall be independent of other building ventilation
systems.
601.4 Contamination prevention. Exhaust ducts under posi-
tive pressure, chimneys, and vents shall not extend into or pass
through ducts or plenums.
SECTION 602
PLENUMS
602.1 General. Supply, return, exhaust, relief and ventilation
air plenums shall be limited to uninhabited crawl spaces, areas
above a ceiling or below the floor, attic spaces and mechanical
equipment rooms. Plenums shall be limited to one fire area.
Fuel-fired appliances shall not be installed within a plenum.
602.2 Construction. Plenum enclosures shall be constructed
of materials permitted for the type of construction classifica-
tion of the building.
The use of gypsum boards to form plenums shall be limited
to systems where the air temperatures do not exceed 125°F
(52°C) and the building and mechanical system design condi-
tions are such that the gypsum board surface temperature will
be maintained above the airstream dew-point temperature. Air
plenums formed by gypsum boards shall not be incorporated in
air-handling systems utilizing evaporative coolers.
602.2.1 Materials exposed within plenums. Except as
required by Sections 602.2. 1 . 1 through 602.2. 1 .5, materials
within plenums shall be noncombustible or shall have a
flame spread index of not more than 25 and a smoke-devel-
oped index of not more than 50 when tested in accordance
with ASTM E 84.
Exceptions:
1. Rigid and flexible ducts and connectors shall con-
form to Section 603.
2. Duct coverings, linings, tape and connectors shall
conform to Sections 603 and 604.
2007 OREGON MECHANICAL SPECIALTY CODE
57
DUCT SYSTEMS
3. This section shall not apply to materials exposed
within plenums in one- and two-family dwellings.
4. This section shall not apply to smoke detectors.
5. Combustible materials enclosed in non-
cumbustible raceways or enclosures, approved
gypsum board assembhes or enclosed in materials
listed and labeled for such application.
L2.1ol Wiring. Combustible electrical or electronic
wiring methods and materials, optical fiber cable, and
optical fiber raceway exposed within a plenum shall have
a peak optical density not greater than 0.50, an average
optical density not greater than 0. 15, and a flame spread
not greater than 5 feet (1524 mm) when tested in accor-
dance with NFPA 262. Only type OFNP (plenum rated
nonconductive optical fiber cable) shall be installed in
plenum-rated optical fiber raceways. Wiring, cable, and
raceways addressed in this section shall be listed and
labeled as plenum rated and shall be installed in accor-
dance with the Electrical Code.
L2.1.2 Fire sprinkler piping. Plastic fire sprinkler
piping exposed within a plenum shall be used only in wet
pipe systems and shall have a peak optical density not
greater than 0.50, an average optical density not greater
than 0.15, and a flame spread of not greater than 5 feet
(1524 mm) when tested in accordance with UL 1887.
Piping shall be listed and labeled.
602.2.1.3 Pneumatic tubing. Combustible pneumatic
tubing exposed within a plenum shall have a peak optical
density not greater than 0.50, an average optical density
not greater than 0.15, and a flame spread of not greater
than 5 feet (1524 mm) when tested in accordance with
UL 1820. Combustible pneumatic tubing shall be listed
and labeled.
602.2.1.4 Combustible electrical equipment. Combus-
tible electrical equipment exposed within a plenum shall
have a peak rate of heat release not greater than 100 kilo-
watts, a peak optical density not greater than 0.50 and an
average optical density not greater than 0.15 when tested
in accordance with UL 2043. Combustible electrical
equipment shall be hsted and labeled.
602.2.1.5 Foam plastic insulation. Foam plastic insula-
tion used as wall or ceiling finish in plenums shall exhibit
a flame spread index of 75 or less and a smoke-developed
index of 450 or less when tested in accordance with
ASTM E 84 and shall also comply with Section
602.2.1.5.1, 602.2.1.5.2 or 602.2.1.5.3.
L2,l,S.l Separation required. The foam plastic
insulation shall be separated from the plenum by a
thermal barrier complying with Section 2603.4 of the
Building Code.
602,2.1.5.2 Approval. The foam plastic insulation
shall be approved based on tests conducted in accor-
dance with Section 2603.9 of the Building Code.
602.2.1.5.3 Covering. The foam plastic insulation
shall be covered by corrosion-resistant steel having a
base metal thickness of not less than 0.0160 inch (0.4
mm).
602.2.1.6 Semiconductor fabrication areas. Group H,
Division 5 fabrication areas and the areas above and
below the fabrication area that share a common air
recirculation path with the fabrication area shall not be
subject to the provisions of Section 602.2.1.
602.3 Stud cavity and joist space plenums. Stud wall cavities
and the spaces between solid floor joists to be utilized as air ple-
nums shall comply with the following conditions:
1 . Such cavities or spaces shall not be utilized as a plenum
for supply air.
2. Such cavities or spaces shall not be part of a required
fire-resistance-rated assembly.
3. Stud wall cavities shall not convey air from more than
one floor level.
4. Stud wall cavities and joist space plenums shall comply
with the floor penetration protection requirements of the
Building Code.
5. Stud wall cavities and joist space plenums shall be iso-
lated from adjacent concealed spaces by approved
fireblocking as required in the Building Code.
602.4 Flood hazard. For structures located in flood hazard
areas, plenum spaces shall be located above the design flood
elevation or shall be designed and constructed to prevent water
from entering or accumulating within the plenum spaces dur-
ing floods up to the design flood elevation. If the plenum spaces
are located below the design flood elevation, they shall be capa-
ble of resisting hydrostatic and hydrodynamic loads and
stresses, including the effects of buoyancy, during the occur-
rence of flooding to the design flood elevation.
SECTION 603
DUCT CONSTRUCTION AND INSTALLATION
603.1 General. An air distribution system shall be designed
and installed to supply the required distribution of air. The
installation of an air distribution system shall not affect the fire
protection requirements specified in the Building Code. Ducts
shall be constructed, braced, reinforced and installed to pro-
vide structural strength and durability.
603.2 Duct sizing. Ducts installed within a single dwelling unit
shall be sized in accordance with ACCA Manual D or other
approved methods. Ducts installed within all other buildings
shall be sized in accordance with the ASHRAE Handbook of
Fundamentals or other equivalent computation procedure.
603.3 Duct classification. Ducts shall be classified based on
the maximum operating pressure of the duct at pressures of
positive or negative 0.5, 1 .0, 2.0, 3.0, 4.0, 6.0 or 10.0 inches of
water column. The pressure classification of ducts shall equal
or exceed the design pressure of the air distribution in which
the ducts are utilized.
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2007 OREGON MECHANICAL SPECIALTY CODE
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603.4 Metallic ducts. All metallic ducts shall be constructed as
specified in the SMACNA HVAC Duct Construction Stan-
dards — Metal and Flexible.
Exception: Ducts installed within single dwelling units
shall have a minimum thickness as specified in Table 603.4.
TABLE 603.4
DUCT CONSTRUCTION MINIMUM SHEET METAL
THICKNESSES FOR SINGLE DWELLING UNITS
GALVANIZED
APPROXIMATE
Minimum
Equivalent
thiclcness
galvanized
ALUMINUM
DUCT SIZE
(inches)
gage no.
B&S GAGE
Round ducts and
enclosed rectangular
ducts
14" or less
0.013
30
26
Over 14"
0.016
28
24
Exposed rectangular
ducts
14" or less
0.016
28
24
Over 14"
0.019
26
22
For SI: 1 inch = 25.4 mm.
603.5 Nonmetallic ducts. Nonmetallic ducts shall be con-
structed with Class or Class 1 duct material in accordance
with UL 181. Fibrous duct construction shall conform to the
SMACNA Fibrous Glass Duct Construction Standards or
NAIMA Fibrous Glass Duct Construction Standards. The
maximum air temperature within nonmetallic ducts shall not
exceed 250°F (121°C).
603.5.1 Gypsum ducts. The use of gypsum boards to form
air shafts (ducts) shall be limited to return air systems where
the air temperatures do not exceed 125°F (52°C) and the
gypsum board surface temperature is maintained above the
airstream dew-point temperature. Air ducts formed by gyp-
sum boards shall not be incorporated in air-handling sys-
tems utilizing evaporative coolers.
603.6 Flexible air ducts and flexible air connectors. Flexible
air ducts, both metallic and nonmetallic, shall comply with
Sections 603.6.1, 603.6.1.1, 603.6.3 and 603.6.4. Flexible air
connectors, both metaUic and nonmetallic, shall comply with
Sections 603.6.2 through 603.6.4.
603.6.1 Flexible air ducts. Flexible air ducts, both metalHc
and nonmetallic, shall be tested in accordance with UL 181.
Such ducts shall be hsted and labeled as Class or Class 1
flexible air ducts and shall be installed in accordance with
Section 304.1.
603.6.1.1 Duct length. Flexible air ducts shall not be
limited in length.
603.6.2 Flexible air connectors. Flexible air connectors,
both metallic and nonmetallic, shall be tested in accordance
with UL 181. Such connectors shall be listed and labeled as
Class or Class 1 flexible air connectors and shall be
installed in accordance with Section 304. 1 .
603.6.2.1 Connector length. Flexible air connectors
shall be limited in length to 14 feet (4267 mm).
603.6.2.2 Connector penetration limitations. Flexible
air connectors shall not pass through any wall, floor or
ceiling.
603.6.3 Air temperature. The design temperature of air to
be conveyed in flexible air ducts and flexible air connectors
shall be less than 250°F (121°C).
603.6.4 Flexible air duct and air connector clearance.
Flexible air ducts and air connectors shall be installed with a
minimum clearance to an apphance as specified in the appli-
ance manufacturer's installation instructions.
603.7 Rigid duct penetrations. Duct system penetrations of
walls, floors, ceilings and roofs and air transfer openings in
such building components shall be protected as required by
Section 607.
603.8 Underground ducts. Ducts shall be approved for under-
ground installation. Metallic ducts not having an approved pro-
tective coating shall be completely encased in a minimum of 2
inches (51 mm) of concrete.
603.8.1 Slope. Ducts shall slope to allow drainage to a point
provided with access.
603.8.2 Sealing. Ducts shall be sealed and secured prior to
pouring the concrete encasement.
603.8.3 Plastic ducts and fittings. Plastic ducts shall be
constructed of PVC having a minimum pipe stiffness of 8
psi (55 kPa) at 5-percent deflection when tested in accor-
dance with ASTM D 2412. Plastic duct fittings shall be con-
structed of either PVC or high-density polyethylene. Plastic
duct and fittings shall be utilized in underground installa-
tions only. The maximum design temperature for systems
utiUzing plastic duct and fittings shall be 150°F (66°C).
603.9 Joints and connections. All joints and connections shall
be sealed and securely fastened in accordance with Sections
603.9.1 and 603.9.2.
603.9.1 Sealants. All joints of duct systems used in the
heating or cooling of a conditioned space, including all
flanged connections to equipment, shall be sealed by means
of tapes, mastics, aerosol sealant, gasketing or other
approved closure systems. Where mastic is used to seal
openings greater than 74 inch (6.4 mm), a combination of
mastic and mesh shall be used.
Exception: Adjustable metal elbow gore, longitudinal
pipe joints, integral seams within a boot fitting or similar
fitting, and integral seams within a "Y" fitting.
603.9.1.1 Rigid fibrous glass ducts. Closure systems
used to seal rigid fibrous glass duct joints shall comply
with UL 181 A and shall be marked "181A-P" for pres-
sure-sensitive tape, "181A-M" for mastic or "181A-H"
for heat-sensitive tape.
603.9.1.2 Flexible air ducts. Closure systems used to
seal flexible air duct joints and flexible air connector
joints shall comply with UL 18 IB and shall be marked
"181B-FX" for tape or "181B-M" for mastic. Tape shall
be a minimum of 12 mil (0.38 mm) total thickness.
603.9.1.3 Metal to metal ducts. Closure systems used to
seal metal to metal duct joints shall comply with UL
<
2007 OREGON MECHANICAL SPECIALTY CODE
59
DUCT SYSTEMS
18 IB and shall be marked "181B-FX" for tape or
"18 IB-M" for mastic. Tape shall be a minimum of 12 mil
(0.38 mm) total thickness, and shall include butyl rubber
adhesive/sealant. Joints of metal to metal duct systems
and their components shall not be sealed with cloth
backed tapes.
5.9,2 Fastening. Duct connections to flanges of air distri-
bution system equipment or sheet metal fittings shall be
mechanically fastened. Crimp joints for round ducts shall
have a contact lap of at least 1 .5 inches (38 mm) and shall be
mechanically fastened by means of at least three sheet metal
screws or rivets equally spaced around the joint. Connec-
tions of metal ducts and the inner core of flexible ducts shall
be mechanically fastened per the manufacturer's installa-
tion instructions. Mechanical fasteners for use with flexible
nonmetallic air ducts shall comply with UL 18 IB and shall
bemarkedl81B-C.
Supports. Ducts shall be supported with approved
hangers at intervals not exceeding 10 feet (3048 mm) or by
other approved duct support systems designed in accordance
with the Building Code. Flexible and other factory-made ducts
shall be supported in accordance with the manufacturer's
installation instructions.
1.11 Furnace connections. Ducts connecting to a furnace
shall have a clearance to combustibles in accordance with the
furnace manufacturer's installation instructions.
L12 Condensation. Provisions shall be made to prevent the
formation of condensation on the exterior of any duct.
hazard areas. For structures in flood hazard
areas, ducts shall be located above the design flood elevation or
shall be designed and constructed to prevent water from enter-
ing or accumulating within the ducts during floods up to the
design flood elevation. If the ducts are located below the design
flood elevation, the ducts shall be capable of resisting hydro-
static and hydrodynamic loads and stresses, including the
effects of buoyancy, during the occurrence of flooding to the
design flood elevation.
t Location. Ducts shall not be installed in or within 4
inches (102 mm) of the earth, except where such ducts comply
with Section 603.8.
.15 Mechanical protection. Ducts installed in locations
where they are exposed to mechanical damage by vehicles or
from other causes shall be protected by approved barriers.
603.16 Weather protection. All ducts including linings, cov-
erings and vibration isolation connectors installed on the exte-
rior of the building shall be protected against the elements.
.17 Registers, grilles and diffusers. Duct registers, grilles
and diffusers shall be installed in accordance with the manufac-
I turer's installation instructions. Volume dampers or other
means of supply air adjustment shall be provided in the branch
ducts or at each individual duct register, grille or diffuser. Each
volume damper or other means of supply air adjustment used in
balancing shall be provided with access.
.17.1 Floor registers. Floor registers shall resist, with-
out structural failure, a 200-pound (90.8 kg) concentrated
load on a 2-inch-diameter (51 mm) disc applied to the most
critical area of the exposed face.
603.17.2 Prohibited locations. Diffusers, registers and
grilles shall be prohibited in the floor or its upward exten-
sion within toilet and bathing room floors required by the
Building Code to have smooth, hard, nonabsorbent sur-
faces.
Exception: Dwelling units.
SECTION 604
INSULATION
604.1 General. Duct insulation shall conform to the require-
ments of Sections 604.2 through 604.13 and Chapter 13 of the
Oregon Structural Specialty Code.
604.2 Surface temperature. Ducts that operate at tempera-
tures exceeding 120°F (49°C) shall have sufficient thermal
insulation to limit the exposed surface temperature to 120°F
(49°C).
604.3 Coverings and linings. Coverings and hnings, includ-
ing adhesives when used, shall have a flame spread index not
more than 25 and a smoke-developed index not more than 50,
when tested in accordance with ASTM E 84, using the speci-
men preparation and mounting procedures of ASTM E 2231.
Duct coverings and linings shall not flame, glow, smolder or
smoke when tested in accordance with ASTM C 4 1 1 at the tem-
perature to which they are exposed in service. The test tempera-
ture shall not fall below 250°F (12rC).
604.4 Foam plastic insulation. Foam plastic used as duct cov-
erings and linings shall conform to the requirements of Section
604.
604.5 Appliance insulation. Listed and labeled appliances
that are internally insulated shall be considered as conforming
to the requirements of Section 604.
604.6 Penetration of assemblies. Duct coverings shall not
penetrate a wall or floor required to have a fire-resistance rating
or required to be fireblocked.
604.7 Identification. External duct insulation and fac-
tory-insulated flexible duct shall be legibly printed or identi-
fied at intervals not greater than 36 inches (914 mm) with the
name of the manufacturer, the thermal resistance /?- value at the
specified installed thickness and the flame spread and
smoke-developed indexes of the composite materials. All duct
insulation product /?- values shall be based on insulation only,
excluding air films, vapor retarders or other duct components,
and shall be based on tested C- values at 75°F (24°C) mean tem-
perature at the installed thickness, in accordance with recog-
nized industry procedures. The installed thickness of duct
insulation used to determine its /?-values shall be determined as
follows:
1. For duct board, duct liner and factory-made rigid ducts
not normally subjected to compression, the nominal
insulation thickness shall be used.
2. For duct wrap, the installed thickness shall be assumed to
be 75 percent (25-percent compression) of nominal
thickness.
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2007 OREGON MECHANICAL SPECIALTY CODE
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>
3. For factory-made flexible air ducts, the installed thick-
ness shall be determined by dividing the difference
between the actual outside diameter and nominal inside
diameter by two.
604.8 Lining installation. Linings shall be interrupted at the
area of operation of a fire damper and at a minimum of 6 inches
(152 mm) upstream of and 6 inches (152 mm) downstream of
electric-resistance and fuel-burning heaters in a duct system.
Metal nosings or sleeves shall be installed over exposed duct
liner edges that face opposite the direction of airflow.
604.9 Thermal continuity. Where a duct liner has been inter-
rupted, a duct covering of equal thermal performance shall be
installed.
604.10 Service openings. Service; openings shall not be con-
cealed by duct coverings unless the exact location of the open-
ing is properly identified.
604.11 Weatherproof barriers. Insulated exterior ducts shall
be protected with an approved weatherproof barrier.
604.12 Internal insulation. Materials used as internal insula-
tion and exposed to the airstream in ducts shall be shown to be
durable when tested in accordance with UL 181. Exposed
internal insulation that is not impermeable to water shall not be
used to line ducts or plenums from the exit of a cooling coil to
the downstream end of the drain pan.
SECTION 605
AIR FILTERS
605.1 General. Heating and air-conditioning systems of the
central type shall be provided with approved air filters. Filters
shall be installed in the return air system, upstream from any
heat exchanger or coil, in an approved convenient location.
Liquid adhesive coatings used on filters shall have a flash point
not lower than 325°F (163°C).
605.2 Approval. Media- type and electrostatic-type air filters
shall be listed and labeled. Media-type air filters shall comply
with UL 900. High efficiency particulate air filters shall com-
ply with UL 586. Electrostatic-type air filters shall comply with
UL 867. Air filters utilized within dwelling units shall be
designed for the intended application and shall not be required
to be listed and labeled.
605.3 Airflow over the filter. Ducts shall be constructed to
allow an even distribution of air over the entire filter.
SECTION 606
SMOKE DETECTION SYSTEMS CONTROL
606.1 Controls required. Air distribution systems shall be
equipped with smoke detectors listed and labeled for installa-
tion in air distribution systems, as required by this section. Duct
smoke detectors shall comply with UL 268A. Other smoke
detectors shall comply with UL 268.
606.2 Where required. Smoke detectors shall be installed
where indicated in Sections 606.2.1 through 606.2.3.
Exception: Smoke detectors shall not be required where air
distribution systems are incapable of spreading smoke
beyond the enclosing walls, floors and ceilings of the room
or space in which the smoke is generated.
606.2.1 Return air systems. Smoke detectors shall be
installed in return air systems with a design capacity greater
than 2,000 cfm (0.9 m^/s), in the return air duct or plenum
upstream of any filters, exhaust air connections, outdoor air
connections, or decontamination equipment and appli-
ances.
Exception: Smoke detectors are not required in the
return air system where all portions of the building
served by the air distribution system are protected by
, area smoke detectors connected to a fire alarm system in
accordance with the Fire Code. The area smoke detec-
tion system shall comply with Section 606.4.
606.2.2 Common supply and return air systems. Where
multiple air-handling systems share common supply or
return air ducts or plenums with a combined design capacity
greater than 2,000 cfm (0.9 mVs), the return air system shall
be provided with smoke detectors in accordance with Sec-
tion 606.2.1.
Exception: Individual smoke detectors shall not be
required for each fan-powered terminal unit, provided
that such units do not have an individual design capacity
greater than 2,000 cfm (0.9 mVs) and will be shut down
by activation of one of the following:
1. Smoke detectors required by Sections 606.2.1 and
606.2.3.
2. An approved area smoke detector system located
in the return air plenum serving such units.
3 . An area smoke detector system as prescribed in the
exception to Section 606.2.1 .
In all cases, the smoke detectors shall comply with Sec-
tions 606.4 and 606.4.1.
606.2.3 Return air risers. Where return air risers serve two
or more stories and serve any portion of a return air system
having a design capacity greater than 15,000 cfm (7.1 mVs),
smoke detectors shall be installed at each story. Such smoke
detectors shall be located upstream of the connection
between the return air riser and any air ducts or plenums.
606.3 Installation. Smoke detectors required by this section
shall be installed in accordance with NFPA 72. The required
smoke detectors shall be installed to monitor the entire airflow
conveyed by the system including return air and exhaust or
relief air. Access shall be provided to smoke detectors for
inspection and maintenance.
606.4 Controls operation. Upon activation, the smoke detec-
tors shall shut down all operational capabilities of the air distri-
bution system in accordance with the listing and labeling of
appliances used in the system. Air distribution systems that are
part of a smoke control system shall switch to the smoke con-
trol mode upon activation of a detector.
2007 OREGON MECHANICAL SPECIALTY CODE
61
DUCT SYSTEft/iS
The duct smoke detectors shall be
connected to a fire alarm system. The actuation of a duct
smoke detector shall activate a visible and audible supervi-
sory signal at a constantly attended location.
TABLE 607.3.1
FIRE DAMPER RATING
1. The supervisory signal at a constantly attended
location is not required where the duct smoke
detector activates the building's alarm-indicating
appliances.
2. In occupancies not required to be equipped with a
fire alarm system, actuation of a smoke detector
shall activate a visible and an audible signal in an
approved location. Duct smoke detector trouble
conditions shall activate a visible or audible signal
in an approved location and shall be identified as
air duct detector trouble.
SECTION 607
DUCT AND TRANSFER OPENINGS
607.1 GemeraL The provisions of this section shall govern the
protection of duct penetrations and air transfer openings in
assemblies required to be protected.
M.l Ducts without dampers. Ducts that penetrate
fire-resistance-rated assemblies and are not required by this
section to have dampers shall comply with the requirements
of Section 712 of the Building Code.
hi Installation. Fire dampers, smoke dampers, combina-
I tion fire/smoke dampers and ceiling radiation dampers located
within air distribution and smoke control systems shall be
installed in accordance with the requirements of this section,
and the manufacturer's installation instructions and listing.
607.2.1 Smoke control system. Where the installation of a
fire damper will interfere with the operation of a required
smoke control system in accordance with Section 513,
approved alternative protection shall be utilized.
.2.2 Hazardous exhaust ducts. Fire dampers for haz-
ardous exhaust duct systems shall comply with Section 510.
^3 Damper testing and ratings. Dampers shall be listed
and bear the label of an approved testing agency indicating
compliance with the standards in this section. Fire dampers
shall comply with the requirements of UL 555. Only fire damp-
ers labeled for use in dynamic systems shall be installed in
heating, ventilation and air-conditioning systems designed to
operate with fans on during a fire. Smoke dampers shall com-
ply with the requirements of UL 555S. Combination
fire/smoke dampers shall comply with the requirements of both
UL 555 and UL 555 S. Ceiling radiation dampers shall comply
with the requirements of UL 555C.
TYPE OF
PENETRATION
MINIMUM
DAMPER
RATING (hour)
Less than 3-hour fire-resistance-rated assemblies
\\
3 -hour or greater fire-resistance-rated assembles
3,
13A Fire protection rating. Fire dampers shall have the
minimum fire protection rating specified in Table 607.3.1
for the type of penetration.
607.3.1.1 Fire damper actuating device. The fire
damper actuating device shall meet one of the following
requirements:
1 . The operating temperature shall be approximately
50°F (27.8°C) above the normal temperature
within the duct system, but not less than 160°F
(71°C).
2. The operating temperature shall be not more than
286°F (141°C) where located in a smoke control
system complying with Section 513.
3. Where a combination fire/smoke damper is
located in a smoke control system complying with
Section 5 1 3, the operating temperature rating shall
be approximately 50°F (27.8°C) above the maxi-
mum smoke control system designed operating
temperature, or a maximum temperature of 350°F
(177°C). The temperature shall not exceed the UL
555S degradation test temperature rating for a
combination fire/smoke damper.
607.3.2 Smoke damper ratings. Smoke damper leakage
ratings shall not be less than Class II. Elevated temperature
ratings shall be riot less than 250°F (121°C).
607,3.2.1 Smoke damper actuation methods. The
smoke damper shall close upon actuation of a listed
smoke detector or detectors installed in accordance with
Section 607 of this code and Sections 907.10 and 907.1 1
of the Building Code and one of the following methods,
as applicable:
1 . Where a damper is installed within a duct, a smoke
detector shall be installed in the duct within 5 feet
(1524 mm) of the damper with no air outlets or
inlets between the detector and the damper. The
detector shall be listed for the air velocity, temper-
ature and humidity anticipated at the point where it
is installed. Other than in mechanical smoke con-
trol systems, dampers shall be closed upon fan
shutdown where local smoke detectors require a
minimum velocity to operate.
2. Where a damper is installed above smoke barrier
doors in a smoke barrier, a spot-type detector listed
for releasing service shall be installed on either
side of the smoke barrier door opening.
3. Where a damper is installed within an unducted
opening in a wall, a spot- type detector listed for
releasing service shall be installed within 5 feet
(1524 mm) horizontally of the damper.
62
2007 OREGON MECHANSCAL SPECIALTY CODE
DUCT SYSTEMS
4. Where a damper is installed in a corridor wall or
ceiling, the damper shall be permitted to be con-
trolled by a smoke detection system installed in the
corridor.
5. Where a total-coverage smoke detector system is
provided within areas served by an H V AC system,
dampers shall be permitted to be controlled by the
smoke detection system.
^4 Access and identification. Fire and smoke dampers
shall be provided with an approved means of access, large
enough to permit inspection and maintenance of the damper
and its operating parts. The access shall not affect the integrity
of fire-resistance-rated assemblies. The access openings shall
not reduce the fire-resistance rating of the assembly. Access
points shall be permanently identified on the exterior by a label
having letters not less than 0.5 inch (12.7 mm) in height read-
ing: FIRE/SMOKE DAMPER, SMOKE DAMPER or FIRE
DAMPER. Access doors in ducts shall be tight fitting and suit-
able for the required duct construction.
^5 Where required. Fire dampers, smoke dampers, combi-
nation fire/smoke dampers and ceiling radiation dampers shall
be provided at the locations prescribed in Sections 607.5.1
through 607.5.5. Where an assembly is required to have both
fire dampers and smoke dampers, combination fire/smoke
dampers or a fire damper and a smoke damper shall be
required.
.5.1 Fire walls. Ducts and air transfer openings permit-
ted in fire walls in accordance with Section 705.11 of the
Building Code shall be protected with listed fire dampers
installed in accordance with their listing.
.5.2 Fire barriers. Ducts and air transfer openings that
penetrate fire barriers shall be protected with listed fire
dampers installed in accordance with their listing. Ducts
and air transfer openings shall not penetrate exit enclosures
and exit passageways except as permitted by Sections
1020.1.2 and 1021.5, respectively, of the Building Code.
Exception: Fire dampers are not required at penetrations
of fire barriers where any of the following apply:
1 . Penetrations are tested in accordance with ASTM
E 1 19 as part of the fire-resistance-rated assembly.
2. Ducts are used as part of an approved smoke con-
trol system in accordance with Section 513 and
where the fire damper would interfere with the
operation of the smoke control system.
3. Such walls are penetrated by ducted HVAC sys-
tems, have a required fire-resistance rating of 1
hour or less, are in areas of other than Group H and
are in buildings equipped throughout with an auto-
matic sprinkler system in accordance with Section
903.3.1.1 or 903.3.1.2 of the Building Code. For
the purposes of this exception, a ducted HVAC
system shall be a duct system for the structure's
HVAC system.6Such a duct system shall be con-
structed of sheet steelnot less than 26 gage [0.0217
inch (0.55 mm)] thickness and shall be continuous
from the air-handling appliance or equipment to
the air outlet and inlet terminals.
607.5.3 Fire partitions. Ducts and air transfer openings
that penetrate fire partitions shall be protected with listed
fire dampers installed in accordance with their listing.
Exception: In occupancies other than Group H, fire
dampers are not required where any of the following
apply:
1. The partitions are tenant separation or corridor
walls in buildings equipped throughout with an
automatic sprinkler system in accordance with
Section 903.3.1.1 or 903.3.1.2 of the Building
Code and the duct is protected as a through pene-
tration in accordance with Section 712 of the
Building Code.
2. The partitions are tenant partitions in covered mall
buildings where the walls are not required by pro-
visions elsewhere in the Building Code to extend
to the underside of the floor or roof deck above.
3. The duct system is constructed of approved mate-
rials in accordance with Section 603 and the duct
penetrating the wall complies with all of the fol-
lowing requirements:
3.1. The duct shall not exceed 100 square inches
(0.06 m^).
3.2. The duct shall be constructed of steel a mini-
mum of 0.0217-inch (0.55 mm) in thickness.
3.3. The duct shall not have openings that commu-
nicate the corridor with adjacent spaces or
rooms.
3.4. The duct shall be installed above a ceiling.
3.5. The duct shall not terminate at a wall register
in the fire-resistance-rated wall.
3.6. A minimum 12-inch-long (305 mm) by
0.060-inch-thick (1.52 mm) steel sleeve shall
be centered in each duct opening. The sleeve
shall be secured to both sides of the wall and
all four sides of the sleeve with minimum
lV2-inch by 1 V2-ihch by 0.060-inch (38 mm
by 38 mm by 1.52 mm) steel retaining angles.
The retaining angles shall be secured to the
sleeve and the wall with No. 10 (M5) screws.
The annular space between the steel sleeve
and the wall opening shall be filled with rock
(mineral) wool batting on all sides.
607.5.4 Corridors/smoke barriers. A listed smoke
damper designed to resist the passage of smoke shall be pro-
vided at each point a duct or air transfer opening penetrates a
smoke barrier wall or a corridor enclosure required to have
smoke and draft control doors in accordance with the Build-
ing Code. Smoke dampers and smoke damper actuation
methods shall comply with Section 607.5.4.1.
Exceptions:
1. Smoke dampers are not required in corridor pene-
trations where the building is equipped throughout
with an approved smoke control system in accor-
dance with Section 513 and smoke dampers are not
2007 OREGON MECHANICAL SPECIALTY CODE
63
DUCT SYSTEMS
necessary for the operation and control of the sys-
tem.
2. Smoke dampers are not required in smoke barrier
penetrations where the openings in ducts are Hm-
ited to a single smoke compartment and the ducts
are constructed of steel.
3. Smoke dampers are not required in corridor pene-
trations where the duct is constructed of steel not
less than 0.019 inch (0.48 mm) in thickness and
there are no openings serving the corridor.
>
^5.4ol Smoke damper. The smoke damper shall
close upon actuation of a listed smoke detector or detec-
tors installed in accordance with the Building Code and
one of the following methods, as applicable:
1 . Where a damper is installed within a duct, a smoke
detector shall be installed in the duct within 5 feet
(1524 nrni) of the damper with no air outlets or
inlets between the detector and the damper. The
detector shall be listed for the air velocity, temper-
ature and humidity anticipated at the point where it
is installed.
2. Where a damper is installed above smoke barrier
doors in a smoke barrier, a spot-type detector listed
for releasing service shall be installed on either
side of the smoke barrier door opening.
3. Where a damper is installed within an unducted
opening in a wall, a spot-type detector listed for
releasing service shall be installed within 5 feet
(1524 mm) horizontally of the damper.
4. Where a damper is installed in a corridor wall, the
damper shall be permitted to be controlled by a
smoke detection system installed in the corridor.
5. Where a total-coverage smoke detector system is
provided within all areas served by an HVAC sys-
tem, dampers shall be permitted to be controlled
by the smoke detection system.
enclosures. Shaft enclosures that are permit-
ted to be penetrated by ducts and air transfer openings shall
be protected with listed fire and smoke dampers installed in
accordance with their listing.
1 . Fire dampers are not required at penetrations of
shafts where:
1.1. Steel exhaust subducts extend at least 22
inches (559 mm) vertically in exhaust
shafts provided that there is a continuous
airflow upward to the outdoors;
1.2. Penetrations are tested in accordance with
ASTM E 119 as part of the fire-resis-
tance-rated assembly;
1.3. Ducts are used as part of an approved smoke
control system in accordance with Section
909 of the Building Code, and where the fire
damper will interfere with the operation of
the smoke control system; or
1.4. The penetrations are in parking garage
exhaust or supply shafts that are separated
from other building shafts by not less than
2-hour fire-resistance-rated construction.
2. In Group B and R occupancies equipped |
throughout with an automatic sprinkler system
in accordance with Section 903.3.1.1 of the
Building Code, smoke dampers are not required
at penetrations of shafts where kitchen, clothes |
dryer, bathroom and toilet room exhaust open-
ings with steel exhaust subducts, having a wall
thickness of at least 0.019 inch (0.48 mm)
extend at least 22 inches (559 mm) vertically
and the exhaust fan at the upper terminus is
powered continuously in accordance with the
provisions of Section 909.11 of the Building
Code, and maintains airflow upward to the out-
doors.
3. Smoke dampers are not required at penetration ^
of exhaust or supply shafts in parking garages
that are separated from other building shafts by
not less than 2-hour fire-resistance-rated con-
struction.
4. Smoke dampers are not required at penetrations
of shafts where ducts are used as part of an
approved mechanical smoke control system
designed in accordance with Section 909 of the
Building Code and where the smoke damper
will interfere with the operation of the smoke
control system.
607.6 Horizontal assemblies. Penetrations by air ducts of a
floor, floor/ceiling assembly or the ceiling membrane of a
roof/ceiling assembly shall be protected by a shaft enclosure
that complies with Section 707 and Sections 716.6.1 through
716.6.3 the Building Code or shall comply with Sections
607.6.1 through 607.6.3.
607.6.1 Through penetrations. In occupancies other than
Groups 1-2 and 1-3, a duct constructed of approved materials
in accordance with Section 603 that peneti'ates a fire-resis-
tance-rated floor/ceiling assembly that connects not more
than two stories is permitted without shaft enclosure protec-
tion provided that a listed fire damper is installed at the floor
line or the duct is protected in accordance with Section
712.4 of the Building Code. For air transfer openings, see
Exception 7 to Section 707.2 of the Building Code.
Exception: A duct is permitted to penetrate three floors
or less without a fire damper at each floor provided it
meets all of the following requirements.
1 . The duct shall be contained and located within the
cavity of a wall and shall be constructed of steel not
less than 0.019 inch (0.48 mm) (26 gage) in thick-
ness.
2. The duct shall open into only one dwelling unit or
sleeping unit and the duct system shall be continu-
ous from the unit to the exterior of the building.
3. The duct shall not exceed 4-inch (102 mm) nomi-
nal diameter and the total area of such ducts shall
64
2007 OREGON MECHANICAL SPEC5ALTY CODE
DUCT SYSTEMS
not exceed 100 square inches (0.065 m^) for any
100 square feet (9.3 m^) of the floor area.
4. The annular space around the duct is protected
with materials that prevent the passage of flame
and hot gases sufficient to ignite cotton waste
where subjected to ASTM E 1 19 time-temperature
conditions under a minimum positive pressure dif-
ferential of 0.01 inch (2.49 Pa) of water at the loca-
tion of the penetration , for the time period
equivalent to the fire-resistance rating of the con-
struction penetrated.
5. Grille openings located in a ceiling of a fire-resis-
tance-rated floor/ceiling or roof/ceiling assembly
shall be protected with a listed ceiling radiation
damper installed in accordance with Section
607.6.2.
607.6.2 Membrane penetrations. Ducts and air transfer
openings constructed of approved materials, in accordance
with Section 603, that penetrate the ceiling membrane of a
fire-resistance-rated floor/ceiling or roof/ceiling assembly
shall be protected with one of the following:
1 . A shaft enclosure in accordance with Sections 707 of
the Building Code.
2. A listed ceiling radiation damper installed at the ceil-
ing line where a duct penetrates the ceiling of a
fire-resistance-rated floor/ceiling or roof/ceiling
assembly.
3. A listed ceiling radiation damper installed at the ceil-
ing line where a diffuser with no duct attached pene-
trates the ceiling of a fire-resistance-rated
floor/ceiling or roof/ceiling assembly.
607.6.2.1 Ceiling radiation dampers. Ceiling radiation
dampers shall be tested in accordance with UL 555C and
installed in accordance with the manufacturer's installa-
tion instructions and listing. Ceiling radiation dampers
are not required where either of the following apply:
1 . Tests in accordance with ASTM E 1 19 have shown
that ceiling radiation dampers are not necessary in
order to maintain the fire-resistance rating of the
assembly.
2. Where exhaust duct penetrations are protected in
accordance with Section 712.4.1.2 of the Building
Code and the exhaust ducts are located within the
cavity of a wall, and do not pass through another
dwelling unit or tenant space.
607.6.3 Nonfire-resistance-rated floor assemblies. Duct
systems constructed of approved materials in accordance
with Section 603 that penetrate nonfire-resistance-rated
floor assemblies shall be protected by any of the following
methods:
1. A shaft enclosure in accordance with Section 707 of
the Building Code.
2. The duct connects not more than two stories, and the
annular space around the penetrating duct is protected
with an approved noncombustible material that
resists the free passage of flame and the products of
combustion.
3. The duct connects not more than three stories, and the
annular space around the penetrating duct is protected
with an approved noncombustible material that
resists the free passage of flame and the products of
combustion, and a listed fire damper is installed at
each floor line.
Exception: Fire dampers are not required in ducts within
individual residential dwelling units.
607.7 Flexible ducts and air connectors. Flexible ducts and
air connectors shall not pass through any fire-resistance-rated
assembly.
2007 OREGON MECHANICAL SPECIALTY CODE
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66 2007 OREGON WiECHANlCAL SPECIALTY CODE
CHAPTER?
COMBUSTION AIR
SECTION 701
GENERAL
701.1 Scope. The provisions of this chapter shall govern the
requirements for combustion and dilution air for fuel-burning
appliances other than gas-fired appliances. The requirements
for combustion and dilution air for gas-iFired appliances shall be
in accordance with Appendix C.
701.2 Combustion and dilution air required. Every room or
space containing fuel-burning appliances shall be provided
with combustion and dilution air as required by this code. Com-
bustion and dilution air shall be provided in accordance with
Section 702, 703, 704, 705, 706 or 707 or shall be provided by
an approved engineered system. Direct vent appliances or
equipment that do not draw combustion air from inside of the
building are not required to be considered in the determination
of the combustion and dilution air requirements. Combustion
air requirements shall be determined based on the simultaneous
operation of all fuel-burning appliances drawing combustion
and dilution air from the room or space.
701.3 Circulation of air. The equipment and appliances within
every room containing fuel-burning appliances shall be
installed so as to allow free circulation of air. Provisions shall
be made to allow for the simultaneous operation of mechanical
exhaust systems, fireplaces or other equipment and appliances
operating in the same room or space from which combustion
and dilution air is being drawn. Such provisions shall prevent
the operation of such appliances, equipment and systems from
affecting the supply of combustion and dilution air.
Exception: Rooms provided with exhaust air systems such
as kitchens, baths, toilet rooms and smoking lounges may
use air supplied through adjacent habitable or occupiable
spaces to compensate for the air exhausted.
701.3.1 Special conditions. In buildings containing com-
bustion appliances, equipment or fireplaces not equipped
with forced or induced draft or separated from the habitable
area, where an individual exhaust appliance exceeds 350
cubic feet per minute (cfm) (165.2 L/s), makcyup air of suf-
ficient quantity to equal that being exhausted shall be sup-
plied to the area being ventilated. In such cases, the
minimum size make-up air duct shall be 6 inches (152 mm)
in diameter or equivalent area.
701.4 Crawl space and attic space. For the purposes of this
chapter, an opening to a naturally ventilated crawl space or attic
space shall be considered equivalent to an opening to the out-
doors.
701.4.1 Crawl space. Where lower combustion air open-
ings connect with crawl spaces, such spaces shall have
unobstructed openings to the outdoors at least twice that
required for the combustion air openings. The height of the
crawl space shall comply with the requirements of the
Building Code and shall be without obstruction to the free
flow of air.
701.4.2 Attic space. Where combustion air is obtained from
an attic area, the attic ventilating openings shall not be sub-
ject to ice or snow blockage, and the attic shall have not less
than 30 inches (762 mm) vertical clear height at its maxi-
mum point. Attic ventilation openings shall be sufficient to
provide the required volume of combustion air and the attic
ventilation required by the Building Code. The combustion
air openings shall be provided with a sleeve of not less than
0,019-inch (0.5 mm) (No. 26 Gage) galvanized steel or
other approved material extending from the appliance
enclosure to at least 6 inches (152 mm) above the top of the
ceiling joists and insulation.
701,5 Prohibited sources. Openings and ducts shall not con-
nect appliance enclosures with a space in which the operation
of a, fan will adversely affect the flow of the combustion air.
Combustion air shall not be obtained from a hazardous loca-
tion, except where the fuel-fired appliances are located within
the hazardous location and are installed in accordance with this
code. Combustion air shall not be taken from a refrigeration
machinery room, except where a refrigerant vapor detector
system is installed to automatically shut off the combustion
process in the event of refrigerant leakage. Combustion air
shall not be obtained from any location below the design flood
elevation.
SECTION 702
INDOOR AIR
702il All air from indoors. Combustion and dilution air shall
be permitted to be obtained entirely from the indoors in build-
ings that are not of unusually tight construction. In buildings of
unusually tight construction, combustion air shall be obtained
from the outdoors in accordance with Section 703, 705, 706 or
707.
702,2 Air from the same room or space. The room or space
containing fuel-burning appliances shall be an unconfined
space as defined in Section 202.
7023 Air from adjacent spaces. Where the volume of the
room in which the fuel-burning appliances are located does not
comply with Section 702.2, additional indoor combustion and |
dilution air shall be obtained by opening the room to adjacent
spaces, so that the combined volume of all communicating
spaces meets the volumetric requirement of Section 702.2.
Openings connecting the spaces shall comply with Section
702.3.1 and 702.3.2.
702.3.1 Number and location of openings. Two openings
shall be provided, one within 1 foot (305 mm) of the ceiling
of the room and one within 1 foot (305 mm) of the floor.
702.3.2 Size of openings. The net free area of each opening,
calculated in accordance with Section 708, shall be a mini-
mum of 1 square inch per 1,000 Btu/h (2201 mm^/kW) of
input rating of the fuel-burning appliances drawing com-
2007 OREGON MECHANICAL SPECIALTY CODE
67
COWIBUSTBON AIB
bustion and dilution air from the communicating spaces and
shall be not less than 100 square inches (64 516 mm^).
SECTION 703
OUTDOOR AIR
LI All air from the outdoors. Where all combustion and
dilution air is to be provided by outdoor air, the required com-
bustion and dilution air shall be obtained by opening the room
to the outdoors. Openings connecting the room to the outdoor
air shall comply with Sections 703.1.1 through 703.1.4.
703.1.1 Number and location of openings. Two openings
shall be provided, one within 1 foot (305 mm) of the ceiling
of the room and one within 1 foot (305 mm) of the floor.
5.1.2 Size of direct openings. The net free area of each
direct opening to the outdoors, calculated in accordance
with Section 709, shall be a minimum of 1 square inch per
4,000 Btu/h (550 mm^/kW) of combined input rating of the
fuel-burning appliances drawing combustion and dilution
air from the room.
703.1.3 Size of horizontal openings. The net free area of
each opening, calculated in accordance with Section 709
and connected to the outdoors through a horizontal duct,
shall be a minimum of 1 square inch per 2,000 Btu/h (1 100
mm^/kW) of combined input rating of the fuel-burning
appliances drawing combustion and dilution air from the
room. The cross-sectional area of the duct shall be. equal to
or greater than the required size of the opening.
703.1.4 Size of vertical openings. The net free area of each
opening, calculated in accordance with Section 709 and
connected to the outdoors through a vertical duct, shall be a
minimum of 1 square inch per 4,000 Btu/h (550 mm^/kW)
of combined input rating of the fuel-burning appliances
drawing combustion and dilution air from the room. The
cross-sectional area of the duct shall be equal to or greater
than the required size of the opening.
SECTION 704
COMBINED USE OF INDOOR AND OUTDOOR AIR
(CONDITION 1)
704.1 Combination of air from indoors and outdoors. This
section shall apply only to appliances located in confined
spaces in buildings not of unusually tight construction. Where
the volumes of rooms and spaces are combined for the purpose
of providing indoor combustion air, such rooms and spaces
shall communicate through permanent openings in compliance
with Sections 702.3.1 and 702.3.2. The required combustion
and dilution air shall be obtained by opening the room to the
outdoors using a combination of indoor and outdoor air, pro-
rated in accordance with Section 704.1.6. The ratio of interior
spaces shall comply with Section 704.1.5. The number, loca-
tion and ratios of openings connecting the space with the out-
door air shall comply with Sections 704.1.1 through 704.1.4.
704.1.1 Number and location of openings. At least two
openings shall be provided, one within 1 foot (305 nrni) of
the ceiling of the room and one within 1 foot (305 mm) of
the floor.
704.1.2 Ratio of direct openings. Where direct openings to
the outdoors are provided in accordance with Section 703. 1 ,
the ratio of direct openings shall be the sum of the net free
areas of both direct openings to the outdoors, divided by the
sum of the required areas for both such openings as deter-
mined in accordance with Section 703. 1 .2.
704.1.3 Ratio of horizontal openings. Where openings
connected to the outdoors through horizontal ducts are pro-
vided in accordance with Section 703.1, the ratio of hori-
zontal openings shall be the sum of the net free areas of both
such openings, divided by the sum of the required areas for
both such openings as determined in accordance with Sec-
tion 703.1.3.
704.1.4 Ratio of vertical openings. Where openings con-
nected to the outdoors through vertical ducts are provided in
accordance with Section 703.1, the ratio of vertical open-
ings shall be the sum of the net free areas of both such open-
ings, divided by the sum of the required areas for both such
openings as determined in accordance with Section 703. 1 .4.
704.1.5 Ratio of interior spaces. The ratio of interior
spaces shall be the available volume of all communicating
spaces, divided by the required volume as determined in
accordance with Sections 702.2 and 702.3.
704.1.6 Prorating of indoor and outdoor air. In spaces
that utilize a combination of indoor and outdoor air, the sum
of the ratios of all direct openings, horizontal openings, ver-
tical openings and interior spaces shall equal or exceed 1 .
SECTION 705
COMBINED USE OF INDOOR AND OUTDOOR AIR
(CONDITION 2)
705.1 General. This section shall apply only to appliances
located in unconfmed spaces in buildings of unusually tight
construction. Combustion air supplied by a combined use of
indoor and outdoor air shall be supplied through openings and
ducts extending to the appliance room or to the vicinity of the
appliance.
705.1.1 Openings and supply ducts. Openings shall be
provided, located and sized in accordance with Sections
702.3.1 and 702.3.2; additionally, there shall be one open-
ing to the outdoors having a free area of at least 1 square inch
per 5,000 Btu/h (440 mm^/kW) of total input of all appli-
ances in the space.
SECTION 706
FORCED COMBUSTION AIR SUPPLY
706.1 General. Where all combustion air and dilution air is
provided by a mechanical forced-air system, the combustion
air and dilution air shall be supplied at the minimum rate of 1
cfm per 2,400 Btu/h [0.00067 mV(s » kW)] of combined input
rating of all the fuel-burning appliances served. Each of the
appliances served shall be electrically interlocked to the
mechanical forced-air system so as to prevent operation of the
appliances when the mechanical system is not in operation.
Where combustion air and dilution air is provided by thb build-
ing's mechanical ventilation system, the system shall provide
68
2007 OREGON MECHANICAL SPECIALTY CODE
COMBUSTION AIR
the specified combustion/dilution air rate in addition to the
required ventilation air.
SECTION 707
DIRECT CONNECTION
707.1 General. Fuel-burning appliances that are listed and
labeled for direct combustion air connection to the outdoors
shall be installed in accordance with the manufacturer's instal-
lation instructions.
the louvers fail to open during burner startup and to shut
down the main burner if the louvers close during operation.
709.2 Dampered openings. Where the combustion air open-
ings are provided with volume, smoke or fire dampers, the
dampers shall be electrically interlocked with the firing cycle
of the appliances served, so as to prevent operation of any
appliance that draws combustion and dilution air from the
room when any of the dampers are closed. Manually operated
dampers shall not be installed in combustion air openings.
SECTION 708
COMBUSTION AIR DUCTS
708.1 General. Combustion air ducts shall:
1. Be of galvanized steel complying with Chapter 6 or of
equivalent corrosion-resistant material approved for this
application.
Exception: Within dwelling units, unobstructed stud
and joist spaces shall not be prohibited from convey-
ing combustion air, provided that not more than one
required fireblock is removed.
2. Have a minimum cross-sectional dimension of 3 inches
(76 mm).
3. Terminate in an unobstructed space allowing free move-
ment of combustion air to the appliances.
4. Have the same cross-sectional areas as the free area of
the openings to which they connect.
5. Serve a single appliance enclosure.
6. Not serve both upper and lower combustion air openings
where both such openings are used. The separation
between ducts serving upper and lower combustion air
openings shall be maintained to the source of combus-
tion air.
7. Not be screened where terminating in an attic space.
8. Not slope downward toward the source of combustion
air, where serving the upper required combustion air
opening.
SECTION 710
OPENING LOCATION AND PROTECTION
710.1 General. Combustion air openings to the outdoors shall
comply with the location and protection provisions of Sections
401.4 and 401.5 applicable to outdoor air intake openings.
SECTION 709
OPENING OBSTRUCTIONS
709.1 General. The required size of openings for combustion
and dilution air shall be based on the net free area of each open-
ing. The net free area of an opening shall be that specified by
the manufacturer of the opening covering. In the absence of
such information, openings covered with metal louvers shall be
deemed to have a net free area of 75 percent of the area of the
opening, and openings covered with wood louvers shall be
deemed to have a net free area of 25 percent of the area of the
opening. Louvers and grills shall be fixed in the open position.
Exception: Louvers interlocked with the appliance so that
they are proven to be in the full open position prior to main
burner ignition and during main burner operation. Means
shall be provided to prevent the main burner from igniting if
2007 OREGON MECHANICAL SPECIALTY CODE
69
70 2007 OREGON WiECHANICAL SPECJALTY CODE
CHAPTER 8
CHIMNEYS AND VENTS
SECTION 801
GENERAL
801.1 Scope. This chapter shall govern the installation, mainte-
nance, repair and approval of factory-built chimneys, chimney
liners, vents and connectors. This chapter shall also govern the
utilization of masonry chimneys. Gas-fired appliances shall be
I I vented in accordance with Appendix C.
801.2 General. Every fuel-burning appliance shall discharge
the products of combustion to a vent, factory-built chimney or
masonry chimney, except for appliances vented in accordance
with Section 804. The chimney or vent shall be designed for the
type of appliance being vented.
801.2.1 Oil-fired appliances. Oil-fired appliances shall be
vented in accordance with this code and NFPA 31.
801.3 Masonry chimneys. Masonry chimneys shall be con-
structed in accordance with the Building Code.
801.4 Positive flow. Venting systems shall be designed and
constructed so as to develop a positive flow adequate to convey
all combustion products to the outside atmosphere.
801.5 Design. Venting systems shall be designed in accordance
with this chapter or shall be approved engineered systems.
801.6 Minimum size of chimney or vent. Except as otherwise
provided for in this chapter, the size of the chimney or vent,
serving a single appliance, except engineered systems, shall
have a minimum area equal to the area of the appliance connec-
tion.
L.7 Solid fuel appliance flues. The cross-sectional area of a
flue serving a solid fuel-burning appliance shall be not greater
than three times the cross-sectional area of the appliance flue
collar or flue outlet.
801.8 Abandoned inlet openings. Abandoned inlet openings
in chimneys and vents shall be closed by an approved method.
801.9 Positive pressure. Where an appliance equipped with a
forced or induced draft system creates a positive pressure in the
venting system, the venting system shall be designed and listed
for positive pressure applications.
801.10 Connection to fireplace. Connection of appliances to
chimney flues serving fireplaces shall be in accordance with
Sections 801.10.1 through 801.10.3.
801.10.1 Closure and access. A noncombustible seal shall
be provided below the point of connection to prevent entry
of room air into the flue. Means shall be provided for access
to the flue for inspection and cleaning.
801.10.2 Connection to factory-built fireplace flue. An
appliance shall not be connected to a flue serving a fac-
tory-built fireplace unless the appliance is specifically listed
for such installation. The connection shall be made in accor-
dance with the appliance manufacturer's installation
instructions.
801.10.3 Connection to masonry fireplace flue. A con-
nector shall extend from the appliance to the flue serving a
masonry fireplace such that the flue gases are exhausted
directly into the flue. The connector shall be provided with
access or shall be removable for inspection and cleaning of
both the connector and the flue. Listed direct connection
devices shall be installed in accordance with their listing.
801.11 Multiple solid fuel prohibited. A solid fuel-burning
appliance or fireplace shall not connect to a chimney passage-
way venting another appliance.
801.12 Chimney entrance. Connectors shall connect to a
chimney flue at a point not less than 12 inches (305 mm) above
the lowest portion of the interior of the chimney flue.
801.13 Cleanouts. Masonry chimney flues shall be provided
with a cleanout opening having a minimum height of 6 inches
(152 mm). The upper edge of the opening shall be located not
less than 6 inches (152 mm) below the lowest chimney inlet
opening. The cleanout shall be provided with a tight-fitting,
noncombustible cover.
Exception: Cleanouts shall not be required for chimney
flues serving masonry fireplaces, if such flues are provided
with access through the fireplace opening.
801.14 Connections to exhauster. All apphance connections
to a chimney or vent equipped with a power exhauster shall be
made on the inlet side of the exhauster. All joints and piping on
the positive pressure side of the exhauster shall be listed for
positive pressure applications as specified by the manufac-
turer's installation instructions for the exhauster.
801.15 Fuel-fired appliances. Masonry chimneys utilized to
vent fuel-fired appliances shall be located, constructed and
sized as specified in the manufacturer's installation instruc-
tions for the appliances being vented.
801.16 Flue lining. Masonry chimneys shall be lined. The lin-
ing material shall be compatible with the type of appliance con-
nected, in accordance with the appliance listing and
manufacturer's installation instructions. Listed materials used
as flue linings shall be installed in accordance with their hst-
ings and the manufacturer's installation instructions.
801.16.1 Residential and low-heat appliances (general).
Flue lining systems for use with residential-type and
low-heat appliances shall be limited to the following:
1 . Clay flue lining complying with the requirements of
ASTM C 315 or equivalent. Clay flue lining shall be
installed in accordance with the Building Code.
2. Listed chimney lining systems complying with UL
1777.
3. Other approved materials that will resist, without
cracking, softening or corrosion, flue gases and con-
densate at temperatures up to 1,800°F (982°C).
2007 OREGON MECHANICAL SPECIALTY CODE
71
CHJWiNEYS AMD VENTS
801.17 Space arounct liemg. The space surrounding a flue lin-
ing system or other vent installed within a masonry chimney
shall not be used to vent any other apphance. This shall not pre-
vent the installation of a separate flue lining in accordance with
the manufacturer's installation instructions and this code.
8€)1.1§ Existimg chimneys aed vents. Where an appliance is
permanently disconnected from an existing chimney or vent, or
where an appliance is connected to an existing chimney or vent
during the process of a new installation, the chimney or vent
shall comply with Sections 801.18.1 through 801.18.4.
801.18.1 Size. The chimney or vent shall be resized as nec-
essary to control flue gas condensation in the interior of the
chimney or vent and to provide the appliance or appliances
served with the required draft. For the venting of oil-fired
appliances to masonry chimneys, the resizing shall be in
accordance with NFPA 3 1 .
.18.2 Flee passageways. The flue gas passageway shall
be free of obstructions and combustible deposits and shall
be cleaned if previously used for venting a solid or liquid
fuel-burning appliance or fireplace. The flue liner, chimney
inner wall or vent inner wall shall be continuous and shall be
free of cracks, gaps, perforations or other damage or deteri-
oration which would allow the escape of combustion prod-
ucts, including gases, moisture and creosote. Where an
oil-fired appliance is connected to an existing masonry
chimney, such chimney flue shall be repaired or relined in
accordance with NFPA 3 1 .
8(D1.18.3 Cleanout. Masonry chimneys shall be provided
with a cleanout opening complying with Section 801.13.
Chimneys and vents shall have
air-space clearance to combustibles in accordance with the
Building Code and the chimney or vent manufacturer's
installation instructions.
Exception; Masonry chimneys equipped with a chimney
lining system tested and listed for installation in chimneys
in contact with combustibles in accordance with UL 1777,
and installed in accordance with the manufacturer's
instructions, shall not be required to have clearance
between combustible materials and exterior surfaces of
the masonry chimney. Noncombustible fireblocking shall
be provided in accordance with the Building Code.
801.19 Meltistory prohitoited. Common venting systems for
appliances located on more than one floor level shall be prohib-
ited, except where all of the appliances served by the common
vent are located in rooms or spaces that are accessed only from
the outdoors. The appliance enclosures shall not communicate
with the occupiable areas of the building.
801.20 Plastic vent joints. Plastic pipe and fittings used to vent
appliances shall be installed in accordance with the pipe manu-
facturer's installation instructions and the appliance manufac-
turer's installation instructions. Solvent cement joints between
ABS pipe and fittings shall be cleaned. Solvent cement joints
between CPVC and PVC pipe and fittings shall be primed. The
primer shall be a contrasting color.
Exception: Where compliance with this section would con-
flict with the appliance manufacturer's installation instruc-
tions.
SECTION 802
VENTS
802.1 General. All vent systems shall be listed and labeled.
Type L vents and pellet vents shall be tested in accordance with
UL641.
802.2 Vent application. The application of vents shall be in
accordance with Table 802.2.
TABLE 802.2
VENT APPLICATION
VENT TYPES
APPLIANCE TYPES
Type L oil vents
Oil-burning appliances listed and labeled for
venting with Type L vents; gas appliances
listed and labeled for venting with Type B
vents.
Pellet vents
Pellet fuel-burning appliances listed and
labeled for venting with pellet vents.
802.3 Installation. Vent systems shall be sized, installed and
terminated in accordance with the vent and appliance manufac-
turer's installation instructions.
802.4 Vent termination caps required. Type L vents shall ter-
minate with a listed and labeled cap in accordance with the vent
manufacturer's installation instructions.
802.5 Type L vent terminations. Type L vents shall terminate
not less than 2 feet (610 mm) above the highest point of the roof
penetration and not less than 2 feet (610 mm) higher than any
portion of a building within 10 feet (3048 mm).
802.6 Minimum vent heights. Vents shall terminate not less
than 5 feet (1524 mm) in vertical height above the highest con-
nected appliance flue collar.
Exceptions:
1. Venting systems of direct vent appliances shall be
installed in accordance with the appliance and the
vent manufacturer's instructions.
2. Appliances listed for outdoor installations incorporat-
ing integral venting means shall be installed in accor-
dance with their listings and the manufacturer's
installation instructions.
3. Pellet vents shall be installed in accordance with the
appliance and the vent manufacturer's installation
instructions.
802.7 Support of vents. All portions of vents shall be ade-
quately supported for the design and weight of the materials
employed.
802.8 Insulation shield. Where vents pass through insulated
assemblies, an insulation shield constructed of not less than
No. 26 Gage sheet metal shall be installed to provide clearance
between the vent and the insulation material. The clearance
shall be not less than the clearance to combustibles specified by
the vent manufacturer's installation instructions. Where vents
pass through attic space, the shield shall terminate not less than
2 inches (51 mm) above the insulation materials and shall be
secured in place to prevent displacement. Insulation shields
provided as part of a listed vent system shall be installed in
accordance with the manufacturer's installation instructions.
72
2007 OREGON MECHANICAL SPECIALTY CODE
SECTION 803
CONNECTORS
803.1 Connectors required. Connectors shall be used to con-
nect appliances to the vertical chimney or vent, except where
the chimney or vent is attached directly to the appliance.
803.2 Location. Connectors shall be located entirely within the
room in which the connecting appliance is located, except as pro-
vided for in Section 803 . 1 0.4. Where passing through an unhealed
space, a connector shall not be constructed of single-wall pipe.
803.3 Size. The connector shall not be smaller than the size of
the flue collar supplied by the manufacturer of the appliance.
Where the appliance has more than one flue outlet, and in the
absence of the manufacturer's specific instructions, the con-
nector area shall be not less than the combined area of the flue
outlets for which it acts as a common connector.
803.4 Branch connections. All branch connections to the vent
connector shall be made in accordance with the vent manufac-
turer's instructions.
803.5 Manual dampers. Manual dampers shall not be
installed in connectors except in chimney connectors serving
solid fuel-burning appliances.
803.6 Automatic dampers. Automatic dampers shall be listed
and labeled in accordance with UL 17 for oil-fired heating
appliances. The dampers shall be installed in accordance with
the manufacturer's installation instructions. An automatic vent
damper device shall not be installed on an existing appliance
unless the appliance is listed and labeled and the device is
installed in accordance with the terms of its listing. The name
of the installer and date of installation shall be marked on a
label affixed to the damper device.
803.7 Connectors serving two or more appliances. Where
two or more connectors enter a common vent or chimney, the
smaller connector shall enter at the highest level consistent
with available headroom or clearance to combustible material.
803.8 Vent connector construction. Vent connectors shall be
constructed of metal. The minimum nominal thickness of the
connector shall be 0.019 inch (0.5 mm) (No. 28 Gage) for galva-
nized steel, 0.022 inch (0.6 mm) (No. 26 B & S Gage) for copper,
and 0.020 inch (0.5 mm) (No. 24 B & S Gage) for aluminum.
803.9 Chimney connector construction. Chimney connec-
tors for low-heat appliances shall be of sheet steel pipe having
resistance to corrosion and heat not less than that of galvanized
steel specified in Table 803.9(1). Connectors for medium-heat
appliances and high-heat appliances shall be of sheet steel not
less than the thickness specified in Table 803.9(2).
TABLE 803.9(1)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR
LOW-HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM NOMINAL THICKNESS
(galvanized) (inches)
5 and smaller
0.022 (No. 26 Gage)
Larger than 5 and up to 10
0.028 (No. 24 Gage)
Larger than 10 and up to 16
0.034 (No. 22 Gage)
Larger than 16
0.064 (No. 16 Gage)
CHIMNEYS AND VENTS
TABLE 803.9(2)
MINIMUM CHIMNEY CONNECTOR THICKNESS FOR
MEDIUM- AND HIGH-HEAT APPLIANCES
AREA
(square inches)
EQUIVALENT ROUND
DIAMETER
(inches)
MINIMUM NOMINAL
THICKNESS
(inches)
0-154
0-14
0.060 (No. 16 Gage)
155-201
15-16
0.075 (No. 14 Gage)
202-254
17-18
0.105 (No. 12 Gage)
Greater than 254
Greater than 18
0.135 (No. 10 Gage)
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mnf .
803.10 Installation. Connectors shall be installed in accor-
dance with Sections 803.10.1 through 803.10.6.
803.10.1 Supports and joints. Connectors shall be sup-
ported in an approved manner, and joints shall be fas-
tened with sheet metal screws, rivets or other approved
means.
803.10.2 Length. The maximum horizontal length of a sin-
gle-wall connector shall be 75 percent of the height of the
chimney or vent.
803.10.3 Connection. The connector shall extend to the
inner face of the chimney or vent liner, but not beyond. A
connector entering a masonry chimney shall be cemented to
masonry in an approved manner. Where thimbles are
installed to facilitate removal of the connector from the
masonry chimney, the thimble shall be permanently
cemented in place with high-temperature cement.
803.10.4 Connector pass-through. Chimney connectors
shall not pass through any floor or ceiling, nor through a
fire-resistance-rated wall assembly. Chimney connectors
for domestic-type appliances shall not pass through walls or
partitions constructed of combustible material to reach a
masonry chimney unless:
1 . The connector is labeled for wall pass-through and is
installed in accordance with the manufacturer's
instructions;
2. The connector is put through a device labeled for wall
pass-through; or
3. The connector has a diameter not larger than 10
inches (254 mm) and is installed in accordance with
one of the methods in Table 803.10.4. Concealed
metal parts of the pass-through system in contact with
flue gases shall be of stainless steel or equivalent
material that resists corrosion, softening or cracking
uptol,800°F(980°C).
803.10.5 Pitch. Connectors shall rise vertically to the
chimney or vent with a minimum pitch equal to
one-fourth unit vertical in 12 units horizontal (2-percent
slope).
For SI: 1 inch = 25.4 mm.
2007 OREGON MECHANICAL SPECIALTY CODE
73
CHIMNEYS AND VENTS
TABLE 803.10.4
CHIfVJNEY CONNECTOR SYSTEMS AND CLEARANCES
TO COMBUSTIBLE WALL MATERIALS FOR
DOMESTIC HEATING APPLIANCES^"''''
System A
(12-inch clearance)
A 3.5-inch-thick brick wall shall be framed
into the combustible wall. A 0.625 -inch-thick
fire-clay Hner (ASTM C 315 or equivalent)*
shall be firmly cemented in the center of the
brick wall maintaining a 12-inch clearance to
combustibles. The clay liner shall run from
the outer surface of the bricks to the inner
surface of the chimney liner.
System B
(9-inch clearance)
A labeled solid-insulated factory-built chimney
section (1-inch insulation) the same inside
diameter as the connector shall be utilized.
Sheet metal supports cut to maintain a 9-inch
clearance to combustibles shall be fastened to
the wall surface and to the chimney section.
Fasteners shall not penetrate the chimney flue
liner. The chimney length shall be flush with
the masonry chimney liner and sealed to the
masonry with water- insoluble refractory
cement. Chimney manufacturers' parts shall be
utilized to securely fasten the chimney
connector to the chimney section.
System C
(6-inch clearance)
A sheet metal (minimum number 24 Gage)
ventilated thimble having two 1-inch air
channels shall be installed with a sheet steel
chimney connector (minimum number 24
Gage). Sheet steel supports (minimum number
24 Gage) shall be cut to maintain a 6-inch
clearance between the thimble and
combustibles. One side of the support shall be
fastened to the wall on all sides. Glass-fiber
insulation shall fill the 6-inch space between
the thimble and the supports.
System D
(2-inch clearance)
A labeled solid-insulated factory-built chimney
section (1-inch insulation) with a diameter 2
inches larger than the chimney connector shall
be installed with a sheet steel chimney
connector (minimum number 24 Gage). Sheet
metal supports shall be positioned to maintain
a 2-inch clearance to combustibles and to hold
the chimney connector to ensure that a 1-inch
airspace surrounds the chimney connector
through the chimney section. The steel support
shall be fastened to the wall on all sides and the
chimney section shall be fastened to the
supports. Fasteners shall not penetrate the liner
of the chimney section.
For SI: 1 inch = 25.4 mm, 1 .0 Btu x in/ft^ » h » °F = 0. 144 W/m^ " K.
a. Insulation material that is part of the wall pass-through system shall be
noncombustible and shall have a thermal conductivity of 1 .0 Btu x in/ft^ "h"
°F or less.
b. All clearances and thicknesses are minimums.
c. Materials utilized to seal penetrations for the connector shall be
noncombustible.
d. Connectors for all systems except System B shall extend through the wall
pass-through system to the inner face of the flue liner.
e. ASTM C 315.
803.1(1).6 Clearances. Connectors shall have a minimum
clearance to combustibles in accordance with Table 803 .10.6.
The clearances specified in Table 803.10.6 apply, except
where the listing and labeling of an apphance specifies a dif-
ferent clearance, in which case the labeled clearance shall
apply. The clearance to combustibles for connectors shall be
reduced only in accordance with Section 308.
TABLE 803.10.6
CONNECTOR CLEARANCES TO COMBUSTIBLES
TYPE OF APPLIANCE
MINIMUM CLEARANCE
(Inches)
Domestic-type appliances
Chimney and vent connectors
Electric and oil incinerators
Oil and solid fuel appliances
Oil appliances labeled for venting
with Type L vents
18
18
9
Commercial, industrial-type appliances
Low-heat appliances
Chimney connectors
Oil and solid fuel boilers, furnaces
and water heaters
Oil unit heaters
Other low-heat industrial appliances
18
18
18
Medium-heat appliances
Chimney connectors
All oil arid solid fuel appUances
36
High-heat appliances
Masonry or metal connectors
All oil and solid fuel appliances
(As determined by the
code official)
For SI: 1 inch = 25.4 mm.
SECTION 804
DIRECT-VENT, INTEGRAL VENT AND
MECHANICAL DRAFT SYSTEI\fflS
804.1 Direct-vent termmatioms. Vent terminals for
direct- vent appliances shall be installed in accordance with the
manufacturer's installation instructions
804o2 Appliances with integral vents. Appliances incorporat-
ing integral venting means shall be installed in accordance with
their listings and the manufacturer's installation instructions.
11.2.1 Terminal clearances. Appliances designed for nat-
ural draft venting and incorporating integral venting means
shall be located so that a minimum clearance of 9 inches
(229 mm) is maintained between vent terminals and from
any openings through which combustion products enter the
building. Appliances using forced draft venting shall be
located so that a minimum clearance of 12 inches (305 mm)
is maintained between vent terminals and from any open-
ings through which combustion products enter the building.
74
2007 OREGON MECHANICAL SPECIALTY CODE
CHIMNEYS AND VENTS
804.3 Mechanical draft systems. ^Mechanical draft systems of
either forced or induced draft design shall comply with Sec-
tions 804.3.1 through 804.3.7. !
804.3.1 Forced draft systems. Forced draft systems and all
portions of induced draft systehis under positive pressure
during operation shall be designed and installed so as to be
gas tight to prevent leakage of combustion products into a
building.
804.3.2 Automatic shutoff. Power exhausters serving auto-
matically fired appliances shall be electrically connected to
each appliance to prevent operation of the appliance when
the power exhauster is not in operation.
804.3.3 Termination. The termination of chimneys or vents
equipped with power exhausters shall be located a minimum
of 10 feet (3048 mm) from the lot line or from adjacent
buildings. The exhaust shall be directed away from the
building.
804.3.4 Horizontal terminations. Horizontal terminations
shall comply with the following requirements:
1. Where located adjacent to walkways, the termination
of mechanical draft systems shalTbe not less than 7
feet (2134 mm) above the level of the walkway.
2. Vents shall terminate at least 3 feet (914 mm) above
any forced air inlet located within 1 feet (3 048 mm) .
3. The vent system shall terminate at least 4 feet (1219
mm) below, 4 feet (1219 mm) horizontally from or 1
foot (305 mm) above any door, window or gravity air
inlet into the building.
4. The vent termination point shall not be located closer
than 3 feet (914 mm) to an interior corner formed by
two walls perpendicular to each other.
5. The vent termination shall not be mounted directly
above or within 3 feet (914 mm) horizontally from an
oil tank vent or gas meter.
6. The bottom of the vent termination shall be located at
least 12 inches (305 mm) above finished grade.
1.3.5 Vertical terminations. Vertical terminations shall
comply with the following requirements:
1. Where located adjacent to walkways, the termination
of mechanical draft systems shall be not less than 7
feet (2134 mm) above the level of the walkway.
2. Vents shall terminate at least 3 feet (914 mm) above
any forced air inlet located within 10 feet (3048 mm)
horizontally.
3. Where the vent termination is located below an adja-
cent roof structure, the termination point shall be
located at least 3 feet (914 mm) from such structure.
4. The vent shall terminate at least 4 feet (1219 mm)
below, 4 feet (1219 mm) horizontally from or 1 foot
(305 mm) above any door, window or gravity air inlet
for the building.
5. A vent cap shall be installed to prevent rain from
entering the vent system.
6. The vent termination shall be located at least 3 feet
(914 mm) horizontally from any portion of the roof
structure.
804.3.6 Exhauster connections. An appliance vented by
natural draft shall not be connected into a vent, chimney or
vent connector on the discharge side of a mechanical flue
exhauster.
804.3.7 Exhauster sizing. Mechanical flue exhausters and
the vent system served shall be sized and installed in accor-
dance with the manufacturer's installation instructions.
804.3.8 Mechanical draft systems for manually fired
appUances and fireplaces. A mechanical draft system shall
be permitted to be used with manually fired appliances and
fireplaces where such system complies with all of the fol-
lowing requirements:
1. The mechanical draft device shall be listed and
installed in accordance with the manufacturer's
installation instructions.
2. A device shall be installed that produces visible and
audible warning upon failure of the mechanical draft
device or loss of electrical power, at any time that the
mechanical draft device is turned on. This device
shall be equipped with a battery backup if it receives
power from the building wiring.
3. A smoke detector shall be installed in the room with
the appliance or fireplace. This device shall be
equipped with a battery backup if it receives power
from the building wiring.
SECTION 805
FACTORY-BUILT CHIMNEYS
805.1 Listing. Factory-built chimneys shall be listed and
labeled and shall be installed and terminated in accordance
with the manufacturer's installation instructions.
805.2 Solid fuel appliances. Factory-built chinmeys installed
in dwelling units with solid fuel-burning appliances shall com-
ply with the Type HT requirements of UL 103 and shall be
marked "Type HT" and "Residential Type and Building Heat-
ing Appliance Chimney."
Exceptions:
1. Chimneys for use with open combustion chamber
fireplaces shall comply with the requirements of UL
103 and shall be marked "Residential Type and
Building Heating Appliance Chimney."
2. Chimneys for use with open combustion chamber
appliances installed in buildings other than dwelling
units shall comply with the requirements of UL 103
and shall be marked "Building Heating Appliance
Chimney" or "Residential Type and Building Heating
Appliance Chimney."
805.3 Factory-built fireplaces. Chimneys for use with fac-
tory-built fireplaces shall comply with the requirements of UL
127.
2007 OREGON MECHANICAL SPECIALTY CODE
75
CHIMMEYS AND VENTS
MBA Support. Where factory-built chimneys are supported
by structural members, such as joists and rafters, such mem-
bers shall be designed to support the additional load.
8(0)5.5 Mediinm-Itieat appMaeces. Factory-built chimneys for
medium-heat appliances producing flue gases having a tem-
perature above 1,000°F (538°C), measured at the entrance to
the chimney, shall comply with UL 959.
§05,6 Becorative sliroeds. Decorative shrouds shall not be
installed at the termination of factory-built chimneys except
where such shrouds are listed and labeled for use with the spe-
cific factory-built chimney system and are installed in accor-
dance with Section 304.1.
8(06.1 Geeeral. Metal chimneys shall be constructed and
installed in accordance with NFPA 211.
76 2007 OREGON MECHANICAL SPECIALTY CODE
CHAPTER 9
SPECIFIC APPLIANCES, FIREPLACES AND
SOLID FUEL-BURNING EQUIPMENT
SECTION 901
GENERAL
901.1 Scope. This chapter shall govern the approval, design,
^ installation, construction, alteration and repair of the appli-
ances and equipment specifically identified herein and fac-
tory-built fireplaces. The approval, design, installation,
^ construction, alteration and repair of gas-fired appliances shall
I I be regulated by Appendix C.
901.2 General. The requirements of this chapter shall apply to
the mechanical equipment and appliances regulated by this
chapter, in addition to the other requirements of this code.
901.3 Hazardous locations. Fireplaces and solid fuel-burning
appliances shall not be installed in hazardous locations.
L.4 Fireplace accessories. Listed fireplace accessories shall
be installed in accordance with the conditions of the listing and
the manufacturer's installation instructions.
SECTION 902
MASONRY FIREPLACES
E.l General. Masonry fireplaces shall be constructed in
accordance with the Building Code.
SECTION 905
FIREPLACE STOVES AND ROOM HEATERS
905.1 General. Fireplace stoves and solid-fuel-type room
heaters shall be listed and labeled and shall be installed in
accordance with the conditions of the listing. Fireplace stoves
shall be tested in accordance with UL 737. Solid-fuel-type
room heaters shall be tested in accordance with UL 1482. Fire-
place inserts intended for installation in fireplaces shall be
listed and labeled in accordance with the requirements of UL
1482 and shall be installed in accordance with the manufac-
turer's installation instructions.
905.2 Connection to fireplace. The connection of solid fuel
appliances to chimney flues serving fireplaces shall comply
with Sections 801.7 and 801.10.
SECTION 906
FACTORY-BUILT BARBECUE APPLIANCES
906.1 General. Factory-built barbecue appliances shall be of
an approved type and shall be installed in accordance with the
manufacturer's installation instructions, this chapter and Chap-
ters 3, 5, 7, 8 and Appendix C. I I
SECTION 903
FACTORY-BUILT FIREPLACES
kl General. Factory-built fireplaces shall be listed and
labeled and shall be installed in accordance with the conditions
of the listing. Factory-built fireplaces shall be tested in accor-
dance with UL 127.
.2 Hearth extensions. Hearth extensions of approved fac-
tory-built fireplaces and fireplace stoves shall be installed in
accordance with the listing of the fireplace. The hearth exten-
sion shall be readily distinguishable from the surrounding floor
area.
.3 Unvented gas log heaters. An unvented gas log heater
shall not be installed in a factory-built fireplace unless the fire-
place system has been specifically tested, listed and labeled for
such use in accordance with UL 127.
SECTION 904
PELLET FUEL-BURNING APPLIANCES
1.1 General. Pellet fuel-burning appliances shall be listed
and labeled in accordance with ASTM E 1509 and shall be
installed in accordance with the terms of the listing.
SECTION 907
INCINERATORS AND CREMATORIES
907.1 General. Incinerators and crematories shall be listed and
labeled and shall be installed in accordance with the manufac- <
turer's installation instructions.
SECTION 908
COOLING TOWERS, EVAPORATIVE
CONDENSERS AND FLUID COOLERS
908.1 General. A cooHng tower used in conjunction with an
air-conditioning appliance shall be installed in accordance
with the manufacturer's installation instructions.
908.2 Access. Cooling towers, evaporative condensers and
fluid coolers shall be provided with ready access.
908.3 Location. Cooling towers, evaporative condensers and
fluid coolers shall be located to prevent the discharge vapor
plumes from entering occupied spaces. Plume discharges shall
be not less than 5 feet (1524 mm) above or 20 feet (6096 nmi)
away from any ventilation inlet to a building. Location on the
property shall be as required for buildings in accordance with
the Building Code.
2007 OREGON MECHANICAL SPECIALTY CODE
77
SPECIFIC APPLIANCES, FIREPLACES AND SOLDO FUEL-BURNING EQUIPR/IENT
>
908.4 Support amdl amdnorage. Supports for cooling towers,
evaporative condensers and fluid coolers shall be designed in
accordance with the Building Code. Seismic restraints shall be
as required by the Building Code.
^. Water supplies and protection shall be as
required by the Plumbing Code.
ige. Drains, overflows and blowdown provisions
shall be indirectly connected to an approved disposal location.
Discharge of chemical waste shall be approved by the appro-
priate regulatory authority.
VEMTED WALL FURNACES
9©9.1 GeeeraL Vented wall furnaces shall be installed in
accordance with their listing and the manufacturer's installa-
tion instructions. Oil-fired furnaces shall be tested in accor-
dance with UL 730.
Ji.2 Locattnom. Vented wall furnaces shall be located so as not
to cause a fire hazard to walls, floors, combustible furnishings
or doors. Vented wall furnaces installed between bathrooms
and adjoining rooms shall not circulate air from bathrooms to
other parts of the building.
3 Door swing. Vented wall furnaces shall be located so
that a door cannot swing within 12 inches (305 mm) of an air
inlet or air outlet of such furnace measured at right angles to the
opening. Doorstops or door closers shall not be installed to
obtain this clearance.
^A Beets prohibited. Ducts shall not be attached to wall
furnaces. Casing extension boots shall not be installed unless
listed as part of the appliance.
' valve. A manual shutoff valve shall be
installed ahead of all controls.
.6 Access. Vented wall furnaces shall be provided with
access for cleaning of heating surfaces, removal of burners,
replacement of sections, motors, controls, filters and other
working parts, and for adjustments and lubrication of parts
requiring such attention. Panels, grilles and access doors that
must be removed for normal servicing operations shall not be
attached to the building construction.
The furnace shall be placed such that a drapery or similar'
combustible object will not be nearer than 12 inches (305 mm)
to any portion of the register of the furnace. Floor furnaces shall
not be installed in concrete floor construction built on grade.
The controlling thermostat for a floor furnace shall be located
within the same room or space as the floor furnace or shall be
located in an adjacent room or space that is permanently open
to the room or space containing the floor furnace.
).3 Bracing. The floor around the furnace shall be braced
and headed with a support framework design in accordance
with the Building Code.
A Clearance. The lowest portion of the floor furnace shall
have not less than a 6-inch (152 mm) clearance from the grade
level; except where the lower 6-inch (152 mm) portion of the
floor furnace is sealed by the manufacturer to prevent entrance
of water, the minimum clearance shall be reduced to not less
than 2 inches (5 1 mm). Where these clearances are not present,
the ground below and to the sides shall be excavated to form a
pit under the furnace so that the required clearance is provided
beneath the lowest portion of the furnace. A 12-inch (305 mm)
minimum clearance shall be provided on all sides except the
control side, which shall have an 18-inch (457 mm) minimum
clearance.
SECTI0M911
DUCT FURNACES
911.1 General. Duct furnaces shall be installed in accordance
with the manufacturer's installation instructions. Electric fur-
naces shall be tested in accordance with UL 1995.
SECTION 912
INFRARED RADIANT HEATERS
912.1 Support. Infrared radiant heaters shall be fixed in a
position independent of fuel and electric supply lines. Hangers
and brackets shall be noncombustible material.
912.2 Clearances. Heaters shall be installed with clearances
from combustible material in accordance with the manufac-
turer's installation instructions.
FLOOR FURNACES
D.l General. Floor furnaces shall be installed in accordance
with their listing and the manufacturer's installation instruc-
tions. Oil-fired furnaces shall be tested in accordance with UL
729.
Floor furnaces shall not be installed in the
floor of any aisle or passageway of any auditorium, public hall,
place of assembly, or in any egress element from any such room
or space.
With the exception of wall register models, a floor furnace
shall not be placed closer than 6 inches (152 mm) to the nearest
wall, and wall register models shall not be placed closer than 6
inches (152 mm) to a corner.
SECTION 913
CLOTHES DRYERS
913.1 General. Clothes dryers shall be installed in accordance
with the manufacturer's installation instmctions. Electric resi-
dential clothes dryers shall be tested in accordance with an
approved test standard. Electric commercial clothes dryers
shall be tested in accordance with UL 1240. Electric coin-oper-
ated clothes dryers shall be tested in accordance with UL 2158.
required. Clothes dryers shall be exhausted in
accordance with Section 504.
913.3 Clearances. Clothes dryers shall be installed with clear-
ance to combustibles in accordance with the manufacturer's
instructions.
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SECTION 914
SAUNA HEATERS
914.1 Location and protection. Sauna heaters shall be located
so as to minimize the possibility of accidental contact by a per-
son in the room.
914.1.1 Guards. Sauna heaters shall be protected from
accidental contact by an approved guard or barrier of mate-
rial having a low coefficient of thermal conductivity. The
guard shall not substantially affect the transfer of heat from
the heater to the room.
914.2 Installation. Sauna heaters shall be listed and labeled
and shall be installed in accordance with their listing and the
manufacturer's installation instructions.
914.3 Access. Panels, grilles and aqcess doors that are required
to be removed for normal servicing operations shall not be
attached to the building.
914.4 Heat and time controls. Sauna heaters shall be equipped
with a thermostat that will Umit room temperature to 194°F
(90°C). If the thermostat is not an integral part of the sauna
heater, the heat-sensing element shall be located within 6 inches
(152 mm) of the ceiling. If the heat-sensing element is a capillary
tube and bulb, the assembly shall be attached to the wall or other
support, and shall be protected against physical damage.
914.4.1 Timers. A timer, if provided to control main burner
operation, shall have a maximum operating time of 1 hour.
The control for the timer shall be located outside the sauna
room.
914.5 Sauna room. A ventilation opening into the sauna room
shall be provided. The opening shall be not less than 4 inches
by 8 inches (102 mm by 203 mm) located near the top of the
door into the sauna room.
914.5.1 Warning notice. The following permanent notice,
constructed of approved material, shall be mechanically
attached to the sauna room on the outside:
WARNING: DO NOT EXCEED 30 MINUTES IN
SAUNA. EXCESSIVE EXPOSURE CAN BE HARM-
FUL TO HEALTH. ANY PERSON WITH POOR
HEALTH SHOULD CONSULT A PHYSICIAN
BEFORE USING SAUNA.
The words shaU contrast with the background and the word-
ing shall be in letters not less than 0.25-inch (6.4 mm) high.
Exception: This section shall not apply to one- and
two-family dwellings.
SECTION 915
ENGINE AND GAS TURBINE-POWERED
EQUIPMENT AND APPLIANCES
915.1 General. The installation of hquid-fueled stationary
internal combustion engines and gas turbines, including fuel
storage and piping, shall meet the requirements of NFPA 37.
915.2 Powered equipment and appliances. Permanendy
installed equipment and appliances powered by internal com-
bustion engines and turbines shall be installed in accordance
with the manufacturer's installation instructions and NFPA 37.
SECTION 916
POOL AND SPA HEATERS
916.1 General. Pool and spa heaters shall be installed in accor-
dance with the manufacturer's installation instructions.
Oil-fired pool and spa heaters shall be tested in accordance
with UL 726. Electric pool and spa heaters shall be tested in
accordance with UL 1261.
SECTION 917
COOKING APPLIANCES
917.1 Cooking appliances. Cooking appliances that are
designed for permanent installation, including ranges, ovens,
stoves, broilers, grills, fryers, griddles and barbecues, shall be
listed, labeled and installed in accordance with the manufac-
turer's installation instructions. Oil-burning stoves shall be
tested in accordance with UL 896. Solid fuel-fired ovens shall
be tested in accordance with UL 2162.
917.2 Prohibited location. Cooking apphances designed,
tested, listed and labeled for use in commercial occupancies
shall not be installed within dwelling units or within any area
where domestic cooking operations occur.
917.3 Domestic appliances. Cooking appliances installed
within dwelling units and within areas where domestic cooking
operations occur shall be hsted and labeled as household-type
appliances for domestic use
917.4 Installation of a listed cooking appliance or micro-
wave over a listed cooking top appliance. The installation of
a listed cooking appliance or microwave oven over a listed
cooking top appliance shall conform to the conditions of the
upper appliance's listing and the manufacturer's installation
instructions.
SECTION 918
FORCED-AIR WARM-AIR FURNACES
918.1 Forced-air furnaces. Oil-fired furnaces shall be tested
in accordance with UL 727. Electric furnaces shall be tested in
accordance with UL 1995. Solid fuel furnaces shall be tested in
accordance with UL 391 . Forced-air furnaces shall be installed
in accordance with the listings and the manufacturer's installa-
tion instructions.
918.2 Minimum duct sizes. The minimum unobstructed total
area of the outdoor and return air ducts or openings to a
forced-air warm-air furnace shall be not less than 2 square
inches per 1,000 Btu/h (4402 mm^/kW) output rating capacity
of the furnace and not less than that specified in the furnace
manufacturer's installation instructions. The minimum unob-
structed total area of supply ducts from a forced-air warm-air
furnace shall not be less than 2 square inches for each 1,000
Btu/h (4402 mm^/kW) output rating capacity of the furnace
and not less than that specified in the furnace manufacturer's
installation instructions.
Exception: The total area of the supply air ducts and out-
door and return air ducts shall not be required to be larger
than the minimum size required by the furnace manufac-
turer's installation instructions.
2007 OREGON MECHANICAL SPECIALTY CODE
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SPECIFIC APPLDANCES, FIREPLACES AND SOLID FUEL-BURNING EQUIPMENT
The minimum unobstructed total area of
I the outdoor and return air ducts or openings to a heat pump
shall be not less than 6 square inches per 1,000 Btu/h (13 208
mm^/kW) output rating or as indicated by the conditions of list-
ing of the heat pump. Electric heat pumps shall be tested in
accordance with UL 1995.
918.4 Dampers. Volume dampers shall not be placed in the air
inlet to a furnace in a manner that will reduce the required air to
the furnace.
918.5 Circulating air ducts for forced-air warm-air fur-
naces. Circulating air for fuel-burning, forced-air-type,
warm-air furnaces shall be conducted into the blower housing
from outside the furnace enclosure by continuous air-tight
ducts.
I 918.6 Prohibited sources. Outdoor or return air for a
forced-air heating system shall not be taken from the following
locations:
1. Closer than 10 feet (3048 mm) from an appliance vent
outlet, a vent opening from a plumbing drainage system
I or the discharge outlet of an exhaust fan, unless the outlet
is 3 feet (914 mm) above the outdoor air inlet.
2. Where there is the presence of objectionable odors,
fumes or flammable vapors; or where located less than
10 feet (3048 mm) above the surface of any abutting pub-
lic way or driveway; or where located at grade level by a
sidewalk, street, alley or driveway.
I Exception: Listed outdoor appliances which provide
' both circulating air inlet and vent discharge.
3. A hazardous or insanitary location or a refrigeration
machinery room as defined in this code.
4. A room or space, the volume of which is less than 25 per-
cent of the entire volume served by such system. Where
connected by a permanent opening having an area sized
in accordance with Sections 918.2 and 918.3, adjoining
rooms or spaces shall be considered as a single room or
space for the purpose of determining the volume of such
rooms or spaces.
Exception: The minimum volume requirement shall
not apply where the amount of return air taken from a
room or space is less than or equal to the amount of
supply air delivered to such room or space.
5. A closet, bathroom, toilet room, kitchen, garage,
mechanical room, boiler room or furnace room.
6. A room or space containing a fuel-burning appliance
where such room or space serves as the sole source of
return air.
This shall not apply where the fuel-burning
appliance is a direct- vent appliance.
This shall not apply where the room or space
complies with the following requirements:
2. 1 . The return air shall be taken from a room or
space having a volume exceeding 1 cubic
foot for each 10 Btu/h (9.6 LAV) of com-
bined input rating of all fuel-burning
appliances therein.
2.2. The volume of supply aii' discharged back
into the same space shall be approximately
equal to the volume of return air taken from
the space.
2.3. Return-air inlets shall not be located within
10 feet (3048 mm) of any appliance firebox
or draft hood in the same room or space.
3. This shall not apply to rooms or spaces contain-
ing solid fuel-burning appliances, provided that
return-air inlets are located not less than 10 feet
(3048 mm) from the firebox of such appUances.
918.7 Outside opening protection. Outdoor air intake open-
ings shall be protected in accordance with Section 401.5.
918.8 Return-air limitation. Return air from one dwelling
unit shall not be discharged into another dwelling unit.
SECTION 919
CONVERSION BURNERS
919.1 Conversion burners. The installation of conversion
burners shall conform to ANSI Z21.8.
SECTION 920
UNIT HEATERS
920.1 General, Unit heaters shall be installed in accordance
with the listing and the manufacturer's installation instructions.
Oil-fired unit heaters shall be tested in accordance with UL
731.
920.2 Support. Suspended-type unit heaters shall be sup-
ported by elements that are designed and constructed to accom-
modate the weight and dynamic loads. Hangers and brackets
shall be of noncombustible material. Suspended-type oil-fired
unit heaters shall be installed in accordance with NFPA 31.
920.3 Ductwork. A unit heater shall not be attached to a
warm-air duct system unless listed for such installation.
SECTION 921
VENTED ROOM HEATERS
921.1 General. Vented room heaters shall be listed and labeled
and shall be installed in accordance with the conditions of the
listing and the manufacturer's instructions.
SECTION 922
KEROSENE AND OIL-FIRED STOVES
922.1 General. Kerosene and oil-fired stoves shall be listed
and labeled and shall be installed in accordance with the condi-
tions of the listing and the manufacturer's installation instruc-
tions. Kerosene and oil-fired stoves shall comply with NFPA
3 1 . Oil-fired stoves shall be tested in accordance with UL 896.
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2007 OREGON MECHANICAL SPECIALTY CODE
SPECIFIC APPLIANCES, FIREPLACES AND SOLID FUEL-BURNING EQUIPMENT
II
II
SECTION 923
SMALL CERAMIC KILNS
923.1 General. The provisions of this section shall apply to
listed and unlisted kilns that are used for ceramics, have a maxi-
mum interior volume of 20 cubic feet (0.566 m^) and are used
for hobby and noncommercial purposes.
923.1.1 Installation. Listed kilns shall be installed in accor-
dance with the manufacturer's installation instructions and
the provisions of this code.
923.2 Unlisted kiln installation. Unlisted kilns shall be
installed in accordance with the manufacturer's installation
instructions and the provisions of this code.
923.2.1 Installations inside buildings. In addition to other
requirements specified in this section, interior installation
shall meet the following requirements:
923.2.2 Clearances for interior installation. The sides and
tops of kilns shall be located a minimum of 18 inches (457
mm) from any noncombustible wall surface and 3 feet (914
mm) from any combustible wall surface. Kilns shall be
installed on noncombustible flooring, consisting of at least 2
inches (5 1 mm) of solid masonry or concrete extending at
least 12 inches (305 mm) beyond the base or supporting
members of the kiln.
Exception: These clearances may be reduced, provided
independent testing is provided to and approved by the
building official.
923.2.3 Control side clearance. The clearance on the con-
trol side of a kiln shall not be reduced to less than 30 inches
(762 mm).
923.2.4 Hoods. A canopy-type hood shall be installed
directly above each kiln. The face opening area of the hood
shall be equal to or greater than the top horizontal surface
area of the kiln. The hood shall be constructed of not less
than 0.030-inch (0.76 mm) (No. 22 U.S. gage) galvanized
steel or equivalent and be supported at a height of between
12 inches and 30 inches (305 mm and 762 mm) above the
kiln by noncombustible supports.
Exception: Electric kilns installed with listed exhaust
blowers may be used when marked as being suitable for
the kiln and installed in accordance with manufacturer's
instructions.
923.2.5 Gravity ventilation ducts. Each kiln hood shall be
connected to a gravity ventilation duct extending in a verti-
cal direction to outside the building. This duct shall be of the
same construction as the hood and shall have a cross-sec-
tional area of not less than one-fifteenth of the face opening
of the hood. The duct shall terminate a minimum of 12
inches (305 mm) above any portion of a building within 4
feet (1219 mm) and terminate no less than 4 feet (1219 mm)
from any openable windows or other opening into the build-
ing or adjacent property line. The duct to the outside shall be
shielded, without reduction of duct area, to prevent entrance
of rain into the duct. The duct shall be supported at each sec-
tion by noncombustible supports.
923.2.6 Hood and duct clearances. Every hood and duct
serving a fuel-burning kiln shall have a clearance from com-
bustible construction of at least 18 inches (457 mm). This
clearance may be reduced in accordance with Table 308.6.
923.2.6.1 Makeup air. Provisions shall be made for air to
enter the room in which a kiln is installed at a rate at least
equal to the air being removed through the kiln hood.
923.3 Exterior installations. Kilns shall be installed with min-
imum clearances as specified in Section 923.2.2. Kilns located
under a roof and enclosed by two or more vertical wall surfaces
shall have a hood and gravity ventilation duct installed to com-
ply with Sections 923.2.4 and 923.2.5.
SECTION 924
STATIONARY FUEL CELL POWER SYSTEMS
924.1 General. Stationary fuel cell power systems having a
power output not exceeding 10 MW shall be tested in accordance
with CS A America FC 1 and shall be installed in accordance with
the manufacturer's installation instructions and NFPA 853.
SECTION 925
MASONRY HEATERS
925.1 General. Masonry heaters shall be constructed in accor-
dance with the Building Code.
SECTION 926
GASEOUS HYDROGEN SYSTEMS
926.1 Installation. The installation of gaseous hydrogen sys-
tems shall be in accordance with the applicable requirements of
this code, the Fire Code, Appendix C and the Building Code.
SECTION 927
WOOD STOVES
927.1 Used wood stoves.
Note: For reference only. Not adopted as part of this code.
The installation of used wood stoves defined and regulated by the
Oregon Department of Environmental Quality's OAR Chapter 340,
Division 262 (wood-burning room heaters as used in this code) is
prohibited.
Exceptions:
1 . (a) The woodstove was certified by the Department or the
Administrator on or after July 1, 1986, in accordance with
emission performance and heating efficiency criteria ap-
plicable at the time of certification;
(b) The woodstove has permanently attached an emission
performance label authorized by the Department or the
EPA.
2. Antique wood stoves pursuant to OAR Chapter 340, Divi-
sion 262.
3. Pellet stoves under rules adopted pursuant to OAR Chapter
340, Division 262.
927.2 Labeling for identification.
Note: For reference only. Not adopted as part of this code.
Wood stoves, as defined by the Oregon Department of Environ-
mental Quality OAR Chapter 340, Division 262, are required by
DEQ to bear a certification label.
2007 OREGON MECHANICAL SPECIALTY CODE
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82 2007 OREGON MECHANICAL SPECIALTY CODE
CHAPTER 10
BOILERS, WATER HEATERS AND
PRESSURE VESSELS
SECTION 1001
GENERAL
1001.1 Scope. The puq)ose of this chapter is to establish and
provide minimum standards for the protection of the public
welfare, health and safety, and property by regulating and con-
trolling the location of steam and hot- water boilers, water heat-
ers and pressure vessels. Boilers and pressure vessels and their
related piping are regulated by the Oregon Boiler and Pressure
Vessel Law.
SECTION 1002
WATER HEATERS
1002.1 General. Potable water heaters and hot water storage
tanks shall be listed and labeled and installed in accordance
with the manufacturer's installation instructions, the Plumbing
Code and where applicable this code. All water heaters shall be
capable of being removed without first removing a permanent
portion of the building structure. The potable water connec-
tions and relief valves for all water heaters shall conform to the
requirements of the Plumbing Code.
1002.2 Water heaters utilized for space heating. Water heat-
ers utilized both to supply potable hot water and provide hot
water for space-heating applications shall be listed and labeled
for such applications by the manufacturer and shall be installed
in accordance with the manufacturer's installation instructions
and the Plumbing Code.
1002.2.1 Sizing. Water heaters utilized for both potable
water heating and space -heating applications shall be sized
to prevent the space-heating load from diminishing the
required potable water-heating capacity.
1002.2.2 Temperature limitation. Where a combination
potable water-heating and space-heating system requires
water for space heating at temperatures higher than 140°F
(60°C), a temperature actuated rhixing valve that conforms
to ASSE 1017 shall be provided to temper the water sup-
plied to the potable hot water distribution system to a tem-
perature of 140T (60°C) or less.
1002.3 Supplemental water-heating devices. Potable
water-heating devices that utilize refrigerant-to-water heat
exchangers shall be approved and installed in accordance with
the Plumbing Code and the manufacturer's installation instruc-
tions.
SECTION 1003
PRESSURE VESSELS
1003.1 Scope. The requirements of this section shall apply to the
boiler rooms, combustion air, chimneys and vents, and fuel pip-
ing related to the construction, installation, repair and alteration
of rooms for the installation of boilers and pressure vessels.
1003.2 Workmanship. All equipment, appurtenances,
devices and piping shall be installed in a workmanlike manner
conforming to provisions and intent of this chapter.
SECTION 1004
DEFINITIONS
1004.1 Definitions. Certain words and terms used in this chap-
ter, unless clearly inconsistent with their context, shall mean as
follows:
BOILER. Is defined in ORS 480.515(2).
ORS 480.515(2) is not a part of this code but is reproduced here for
theireader's convenience:
480.515 Definitions for ORS 480.510 to 480.670.
(2) "Boiler" or "boilers" means:
(a) A closed vessel or vessels intended for the heating or vaporiz-
ing of liquids to be used externally to such vessel or vessels by the
application of heat from combustible fuels, electricity or nuclear
energy;
(b) Related appurtenances including but not limited to pressure
piping directly connected and related to the safe operation of a
boiler; and
(c) Pressure piping consisting of boiler or nonboiler external pip-
ing connected to a boiler, but not potable water nonboiler external
piping.
DOMESTIC WATER HEATER. Is defined in ORS
480.525(l)(b).
ORS 480.525(l)(b) is not a part of this code but is reproduced here
for the reader's convenience:
480.525 Exempt vessels.
(l)(b) Domestic water heaters designed for heating potable water,
equipped with an approved pressure-relieving device, containing
only water and that do not exceed:
(a) Capacity of 120 gallons;
(b) Water temperature of 210 degrees Fahrenheit;
(c) Pressure of 150 pounds per square inch gauge pressure; or
(d) Heat input of 200,000 BTU per hour.
SECTION 1005
PERMITS REQUIRED
1005.1 Permits. It shall be unlawful to install any boiler or
pressure vessel regulated by this code without first obtaining a
permit to do so from the building official and an installation
permit from the Oregon Building Codes Division, Boiler and
Pressure Vessel Program.
2007 OREGON MECHANICAL SPECIALTY CODE
83
BOILERS, WATER HEATERS AND PRESSURE VESSELS
SECTION 1006
DETAILED REQUIREMENTS
100(5.1 Safety reqiiirememts. The installation of all boilers
and pressure vessels shall conform to the minimum require-
ments for safety established by this code.
.2 Stack dampers. Stack dampers on boilers fired with oil
or solid fuel shall not close more than 80 percent of the stack
area when closed, except on automatic boilers with prepurge,
automatic draft control and interlock. Operative dampers shall
not be placed within any stack, flue or vent of a gas-fired boiler,
except on an automatic boiler with prepurge, automatic draft
control and interlock.
,1 Expansion tanks. All water heating systems provided
with an air expansion tank shall be securely fastened to the
structure; supports shall be adequate to carry twice the weight
of the tank filled with water without placing any strain on con-
necting piping.
All water heating systems incorporating hot- water tanks or
fluid relief columns shall be installed to prevent freezing under
normal operating conditions.
Package boilers, miniature boilers, low-pressure boilers and
hot- water supply boilers with no manhole on top of shell shall
have a minimum clearance of 2 feet (610 mm) from the ceiling.
SECTION 1011
BOILER ROOM ENCLOSURES
1011.1 Boiler rooms. Boiler rooms and enclosure's and access
thereto shall comply with Chapter 3 of this code and the Build-
ing Code.
SECTION 1012
FLOORS
1012.1 GeeeraL Boilers shall be mounted on floors of
noncombustible construction unless listed for mounting on
combustible floors. The floor and related structural supports
shall be designed as required in the Building Code to carry the
loads imposed by the boiler and appurtenances.
SECTION 1013
CHIMNEYS OR VENTS
1013.1 GeneraL When required, boilers shall be connected to
a chimney or vent as provided for other fuel-burning equip-
ment in Chapter 8 of this code.
.1 GeneraL The discharge from relief valves shall be
piped to within 18 inches (457 mm) of the floor or to an open
receptacle, and when the operating temperature is in excess of
212°F (100°C), shall be equipped with a splash shield or cen-
trifugal separator. When the discharge from safety valves
would result in a hazardous discharge of steam inside the boiler
room, such discharge shall be extended outside the boiler
room. No valve of any description shall be placed between the
safety valve and the atmosphere.
SECTDON 1009
GAS=PRESSURE REGULATORS
1009.1 GeeeraL An approved gas-pressure regulator shall be
installed on gas-fired boilers where the gas supply pressure is
higher than that at which the main burner is designed to operate.
A separate approved gas-pressure regulator shall be installed to
regulate the gas pressure to the pilot or pilots. A separate regula-
tor shall not be required for the pilot or pilots on manufac-
turer-assembled boiler-burner units which have been approved
by the building official and on gas-fired boilers in Group R occu-
pancies of less than six units and in Group M occupancies.
SECTlOi
CLEARANCE FOR ACCESS
.1 Access. When boilers are installed or replaced, clear-
ance shall be provided to allow access for inspection, mainte-
nance and repair, and passageways shall have an unobstructed
width of not less than 1 8 inches (457 mm). Clearance for repair
and cleaning may be provided through a door or access panel
into another area, provided the opening is of sufficient size.
SECTION 1014
DRAINAGE
1014.1 Drains. The boiler room shall have an approved floor
drain or equivalent means for disposing of accumulation of liq-
uid wastes incidental to cleaning or recharging.
SECTION 1015
FUEL SUPPLY PIPING
1015.1 Piping. Fuel supply piping shall conform to Chapter
13, Appendix C or the standards cited in Chapter 15, Refer-
enced Standards.
SECTION 1016
AIR FOR COMBUSTION AND VENTILATION
1016.1 GeneraL Air for combustion and ventilation shall be
according to Chapter 7 or Appendix C of this code.
SECTION 1017
STEAM AND WATER PIPING
Note: Boilers and pressure vessels and related piping are regulated
by the State of Oregon Boiler and Pressure Vessel Law (ORS
480.510 to 480.670).
1017.1 GeneraL Steam piping is regulated according to and under
the jurisdiction of the Oregon Boiler and Pressure Vessel Law and
related administrative rules and the jurisdiction of Oregon Build-
ing Codes Division, Boiler and Pressure Vessel Program. Water
piping for hot- water heating systems and hydronics shall be regu-
lated and installed according to Chapter 12 of this code.
84
2007 OREGON MECHANICAL SPECIALTY CODE
CHAPTER 11
REFRIGERATION
SECTION 1101
GENERAL
1101.1 Scope. This chapter shall govern the design, installa-
tion, construction and repair of refrigeration systems that
vaporize and liquefy a fluid during the refrigerating cycle.
Refrigerant piping design and installation, including pressure
vessels and pressure relief devices, shall conform to this code.
Permanently installed refrigerant storage systems and other
components shall be considered as part of the refrigeration sys-
tem to which they are attached.
Note: Brazing certifications required. A person qualified for in-
spection of brazing or welding of refrigeration piping shall have
a valid certification meeting the requirements in OAR
918-098-1080. A person engaged in the brazing or welding of
refrigeration piping shall have a valid certification meeting the
requirements in OAR 918-440-0015. For refrigeration piping
regulated by the State of Oregon Boiler and Pressure Vessel
Program, see requirements listed in OAR 918-225-0310. All
three of these administrative rules were effective July 1, 2001.
918-098-1080
Refrigeration Inspector Certification
(1) All persons engaged in the inspection of brazing or welding re-
lated to the installation, alteration or repair of refrigeration piping
systems, except as regulated by the Oregon Boiler and Pressure
Vessel Program under OAR Chapter 918, Division 225, shall:
(a) Possess a current and valid A- or B-level Mechanical Inspec-
tor Certification issued under OAR 918-098-0120 or
918-098-0130; and
(b) Successfully complete a training program in accordance with
either Section IX, "Welding and Brazing Qualification" of the
ASME Boiler and Pressure Vessel Code, or AWS B2.2, "Stan-
dard for Brazing Procedure and Performance Qualification" is-
sued by a division-approved organization.
(2) Inspector certification for refrigeration piping in one- and
two-family dwellings is not required.
918-440-0015
Refrigeration Installer Certification
All persons engaged in brazing or welding related to the installa-
tion, alteration or repair of refrigeration piping systems not regu-
lated by the Oregon Boiler and Pressure Vessel Program under
OAR Chapter 918, Division 225, shall be certified in accordance
with the requirements of this rule.
(1) The minimum requirement for persons engaged in brazing or
welding of refrigeration piping systems is a current and valid certif-
ication issued upon completion of a class by a division-approved
certifying organization in brazing or welding in accordance with ei-
ther:
(a) Section IX, Welding and Brazing Qualifications of the
ASME Boiler and Pressure Vessel Code; or
(b) AWS B2.2, Standard for Brazing Procedure and Perfor-
mance Qualification.
(2) Refrigeration systems installed in dwelling units regulated un-
der the One- and Two-Family Dwelling Specialty Code are ex-
empt from this rule.
(3) All refrigeration piping system requirements not regulated by
OAR 918-225-0310 are subject to the Oregon Mechanical Spe-
cialty Code.
918-225-0310
Refrigerant Piping Systems; Components
(1) The requirements of OAR 918-225-0430(5) shall be enforced
under this rule for all refrigerant piping systems consisting of
welded, brazed or mechanically assembled piping and piping fit-
tings exceeding 2 inches NPS, and containing any refrigerant
chemical rated as other than A-1 or B-1 by the American Society of
Heating, Refrigeration and Air Conditioning Engineers (ASHRAE
34) as adopted by the Oregon Mechanical Specialty Code.
(2) One- and two-family dwelling units and air conditioning refrig-
eration systems used solely for human comfort are exempt from
this rule.
(3) All refrigeration piping system requirements other than those
regulated by this rule are subject to the Oregon Mechanical Spe-
cialty Code.
1101.2 Factory-built equipment and appliances. Listed and
labeled self-contained, factory-built equipment and appliances
shall be tested in accordance with UL 207, 412, 471 or 1995.
Such equipment and appliances are deemed to meet the design,
manufacture and factory test requirements of this code if
installed in accordance with their listing and the manufac-
turer's installation instructions.
1101.3 Protection. Any portion of a refrigeration system that
is subject to physical damage shall be protected in an approved
manner.
1101.4 Water connection. Water supply and discharge con-
nections associated with refrigeration systems shall be made in
accordance with this code and the Plumbing Code.
1101.5 Fuel gas connection. Fuel gas devices, equipment and
appliances used with refrigeration systems shall be installed in
accordance with Appendix C.
1101.6 General. Refrigeration systems shall comply with the
requirements of this code and, except as modified by this code,
ASHRAE 15. Ammonia-refrigerating systems shall comply
with this code and, except as modified by this code, ASHRAE
15andIIAR2.
SECTION 1102
SYSTEM REQUIREMENTS
1102.1 General. The system classification, allowable refriger-
ants, maximum quantity, enclosure requirements, location lim-
<
2007 OREGON MECHANICAL SPECIALTY CODE
85
REFRIGERATION
itations, and field pressure test requirements shall be
determined as follows:
1. Determine the refrigeration system's classification, in
accordance with Section 1103.3.
2. Determine the refrigerant classification in accordance
with Section 1103.1.
3. Determine the maximum allowable quantity of refriger-
ant in accordance with Section 1104, based on type of
refrigerant, system classification and occupancy.
4. Determine the system enclosure requirements in accor-
dance with Section 1104.
5. Refrigeration equipment and appliance location and
installation shall be subject to the limitations of Chapter 3.
6. Nonfactory-tested, field-erected equipment and appli-
ances shall be pressure tested in accordance with Section
1108.
1102.2 Refrigerants. The refrigerant shall be that which the
equipment or appliance was designed to utilize or converted to
utilize. Refrigerants not identified in Table 1103.1 shall be
approved before use.
1102.2.1 Mixing. Refrigerants, including refrigerant
blends, with different designations in ASHRAE 34 shall not
be mixed in a system.
Exception; Addition of a second refrigerant is allowed
where permitted by the equipment or appliance manu-
facturer to improve oil return at low temperatures. The
refrigerant and amount added shall be in accordance with
the manufacturer's instructions.
1102.2.2 Purity. Refrigerants used in refrigeration systems
shall be new, recovered or reclaimed refrigerants in accor-
dance with Section 1102.2.2.1, 1102.2.2.2 or 1102.2.2.3.
Where required by the equipment or appliance owner or the
code official, the installer shall furnish a signed declaration
that the refrigerant used meets the requirements of Section
1102.2.2.1, 1102.2.2.2 or 1102.2.2.3.
Exception: The refrigerant used shall meet the purity
specifications set by the manufacturer of the equipment
or appliance in which such refrigerant is used where such
specifications are different from that specified in Sec-
tions 1102.2.2.1, 1102.2.2.2 and 1102.2.2.3.
1102.2.2.1 New refrigerants. Refrigerants shall be of a
purity level specified by the equipment or appliance
manufacturer.
1102.2.2.2 Recovered refrigerants. Refrigerants that
are recovered from refrigeration and air-conditioning
systems shall not be reused in other than the system from
which they were recovered and in other systems of the
same owner. Recovered refrigerants shall be filtered and
dried before reuse. Recovered refrigerants that show
clear signs of contamination shall not be reused unless
reclaimed in accordance with Section 1102.2.2.3.
1102.2.2.3 Reclaimed refrigerants. Used refrigerants
shall not be reused in a different owner's equipment or
appliances unless tested and found to meet the purity
requirements of ARI 700. Contaminated refrigerants
shall not be used unless reclaimed and found to meet the
purity requirements of ARI 700.
SECTION 1103
REFRIGERATION SYSTEM CLASSIFICATION
1103.1 Refrigerant classification. Refrigerants shall be classi-
fied in accordance with ASHRAE 34 as listed in Table 1 103.1.
1103.2 Occupancy classification. Locations of refrigerating
systems are described by occupancy classifications that con-
sider the ability of people to respond to potential exposure to
refrigerants. Where equipment or appliances, other than pip-
ing, are located outside a building and within 20 feet (6096
mm) of any building opening, such equipment or appliances
shall be governed by the occupancy classification of the build-
ing. Occupancy classifications shall be defined as follows:
1 . Institutional occupancy is that portion of premises from
which, because they are disabled, debilitated or con-
fined, occupants cannot readily leave without the assis-
tance of others. Institutional occupancies include, among
others, hospitals, nursing homes, asylums and spaces
containing locked cells.
2. Public assembly occupancy is that portion of premises
where large numbers of people congregate and from
which occupants cannot quickly vacate the space. Public
assembly occupancies include, among others, auditori-
ums, ballrooms, classrooms, passenger depots, restau-
rants and theaters.
3. Residential occupancy is that portion of premises that
provides the occupants with complete independent liv-
ing facilities, including permanent provisions for living,
sleeping, eating, cooking and sanitation. Residential
occupancies include, among others, dormitories, hotels,
multiunit apartments and private residences.
4. Commercial occupancy is that portion of premises where
people transact business, receive personal service or pur-
chase food and other goods. Commercial occupancies
include, among others, office and professional buildings,
markets (but not large mercantile occupancies) and work
or storage areas that do not qualify as industrial occupan-
cies.
5. Large mercantile occupancy is that portion of premises
where more than 100 persons congregate on levels above
or below street level to purchase personal merchandise.
6. Industrial occupancy is that portion of premises that is
not open to the public, where access by authorized per-
sons is controlled, and that is used to manufacture, pro-
cess or store goods such as chemicals, food, ice, meat or
petroleum.
7. Mixed occupancy occurs when two or more occupancies
are located within the same building. When each occu-
pancy is isolated from the rest of the building by tight
walls, floors and ceilings and by self-closing doors, the
requirements for each occupancy shall apply to its por-
tion of the building. When the various occupancies are
not so isolated, the occupancy having the most stringent
requirements shall be the governing occupancy'
86
2007 OREGON MECHANICAL SPECIALTY CODE
i^fi
TABLE
REFRIGERANT CLASSIFICATION, AMOUNT AND TLV-TWA
REFRIGERANT
CHEMICAL
FORMULA
CHEMICAL NAME OR BLEND
HAZARD
CATEGORIES^
REFRIGERANT
CLASSIFICATION
DEGREES
OF HAZARD"
[M] AMOUNT OF REFRIGERANT PER OCCUPIED SPACE
Pounds per
1 ,000 cubic
feet
ppm
g/m^
TLV-TWA'
(ppm)
R-IP
CCl.F
Trichlorofluoromethane
OHH
Al
2-0-0'=
0.39
1,100
6.2
€1,000
R-12^
CCI7F2
Dichlorodifluoromethane
CG,OHH
Al
2-0-0"=
5.6
18,000
90
1,000
R-13«
CCIF3
Chlorotrifluoromethane
CG,OHH
Al
2-0-0^
18
67,000
290
1,000
R-13BP
CBrP,
Bromotrifluoromethane
CG,OHH
Al
2-0-0'=
22
57,000
350
1,000
R-14
CF,
Tetrafluoromethane (carbon tetrafluoride)
CG,OHH
Al
2-0-0'=
16
69,000
250
1,000
R-22
CHCIF2
Chlorodifluoromethane
CG,OHH
Al
2-0-0^
5.5
25,000
89
1,000
R-23
CHF^
Trifluoromethane (fluoroform)
CG,OHH
Al
2-0-0=
7.3
41,000
120
1,000
R-32
CH,F2
Difluoromethane (methylene fluoride)
CG,F,OHH
A2
—
4.2
32,000
68
R-m'^
CCI2FCCIF2
1, l,2-trichloro-l,2,2-trifluoroethane
OHH
Al
2-0-0=
1.2
2,600
20
1,000
R-IU'^
CCIF2CCIF2
1 ,2-dichloro- 1,2,2-tetrafluoroethane
CG,OHH
Al
2-0-0"=
8.7
20,000
140
1,000
R-116
CF3CF3
Hexafluoroethane
CH,OHH
Al
1-0-0
24
69,000
390
R-123
CHCI2CF3
2,2-dichloro-l ,1 ,1 -trifluoroethane
OHH
Bl
2-0-0"=
3.5
9,100
57
50
R-124
CHCIFCF^
2-chloro- 1,1,1 ,2-tetrafluoroethane
CG,OHH
Al
2-0-0"=
3.5
10,000
56
1,000
R-125
CHF2CF,
Pentafluoroethane
CG,OHH
Al
2-0-0"=
21
69,000
340
R-134a
CH2FCF,
1,1,1 ,2-tetrafluoroethane
CG,OHH
Al
2-0-0"=
13
50,000
210
1,000
R-143a
CH.CF,
1,1,1 -trifluoroethane
CG,F,OHH
A2
2-0-0'=
■3.8
18,000
60
R-152a
CH,CHF2
1,1-difluorethane
CG,F,OHH
A2
1-4-0
1.6
9,300
25
—
R-170
CH^CH^
Ethane
CG,F,OHH
A3
2-4-0
0.54
7,000
8.7
1,000
R^218
CF.CF^CF,
Octafluoropropan e
CG,OHH
Al
2-0-0'=
33
69,000 .
530
R-236fa
CF,CH,CF,
1,1,1,3,3,3-hexafluoropropane
CG,OHH
Al
2-0-0'=
21
55,000
—
1,000
R-245fa
CHF2CH2CFt
1,1, 1 ,3 ,3-pentafluoropropane
CG,OHH
Bl
2-0-0'=
12
34,000
—
300
R-290
UH-^C-ri2V-.rl3
Propane
CG,F,OHH
A3
2-4-0
0.56
5,000
9.0
2,500
R400'=
zeotrope
R-12/114
CG,OHH
Al
2-0-0=
9.3
26,000
150
—
R-406A
zeotrope
R-22/600a/142b (55/4/41)
CG,F,OHH
A2
--—
R-401A
zeotrope
R-22/152a/l 24 (53/13/34)
CG,OHH
Al
2-0-0=
4.8
20,000
77
—
R-401B
zeotrope
R-22/152a/124 (61/1 1/28)
CG,OHH
Al
2-0-0=
4.9
21,000
79
—
R-401C
zeotrope
R-22/152a/124 (33/15/52)
CG,OHH
Al
2-0-0=
4.4
17,000
71
R-402A
zeotrope
R-125/290/22 (60/2/38)
CG,OHH
Al
2-0-0=
10
39,000
160
—
R-402B
zeotrope
R-125/290/22 (38/2/60)
CG,OHH
Al
2-0-0=
7.8
32,000
120 .
—
(continued)
[F] TABLE 1103.1— continued
REFRIGERANT CLASSIFICATION, AMOUNT AND TLV-TWA
O
33
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REFRIGERANT
CHEMICAL
FORMULA
CHEMICAL NAME OR BLEND
HAZARD
CATEGORIES^
REFRIGERANT
CLASSIFICATION
degrees of
hazard"
[M] AMOUNT OF REFRIGERANT PER OCCUPIED SPACE
Pounds per
1,000 cubic
feet
ppm
g/m^"
TLV-TWA*
(ppm)
R-403A
zeotrope
R-290/22/2 18 (5/75/20)
CG,OHH
Al
2-0-0^^
—
—
—
—
R-403B
zeotrope
R-290/22/218 (5/56/39)
CG,OHH
Al
2-0-0'^
—
—
—
—
R-404A
zeotrope
R-125/143a/l 34a (44/52/4)
CG,OHH
Al
2-0-0^
17
69,000
280
R-407A
zeotrope
R-32/1 25/1 34a (20/40/40)
CG,OHH
Al
2-0-0^
16
69,000
260
—
R-407B
zeotrope
R-32/1 25/1 34a (10/70/20)
CG,OHH
Al
2-0-0^
18
69,000
290
—
R-407C
zeotrope
R-32/125/134a (23/25/52)
CG,OHH
Al
2-0-0^
15
69,000
240
—
R-407D
zeotrope
R-32/125/134a (15/15/70)
CG,OHH
Al
2-0-0'-'
15
65,000
240
—
R-407E
zeotrope
R-32/125/134a (25/15/60)
CG,OHH
Al
2-0-0*^
15
69,000
240
—
R-408A
zeotrope
R- 1 25/1 43a/22 (7/46/47)
CG,OHH
Al
2-0-0^
10
47,000
170
—
R-409A
zeotrope
R-22/124/142b (60/25/15)
CG.OHH
Al
2-0-0=
4.9
20,000
79
—
R-409B
zeotrope
R-22/124/142b (65/25/10)
CG,OHH
Al
2-0-0=
4.9
20,000
78
—
R410A
zeotrope
R-32/1 25 (50/50)
CG,OHH
Al
2-0-0=
10
55,000
160
—
R-410B
zeotrope
R-32/125 (45/55)
CG,OHH
Al
2-0-0=
11
58,000
180
—
R-411A
zeotrope
R-127/22/152a (1.5/87.5/11.0)
CG,F,OHH
A2
—
—
—
—
—
R-411B
zeotrope
R- 1270/22/1 52a (3/94/3)
CG,F,OHH
A2
—
—
—
—
—
R-507A
azeotrope
R-125/143a (50/50)
CG,OHH
Al
2-0-0=
17
69,000
280
—
R-508A
azeotrope
R-23/1 16 (39/61)
CG,OHH
Al
2-0-0=
14
55,000
220
—
R-508B
azeotrope
R-23/1 16 (46/54)
CG,OHH
Al
2-0-0=
13
52,000
200
—
R-509A
zeotrope
R-22/218 (44/56)
CG,OHH
Al
2-0-0=
12
38,000
190
—
R-600
C-ri3(_ri2C_,ri2C.ri3
Butane
CG,F,OHH
A3
1-4-0
—
—
—
—
R-600a
CH(CH3)2-CH3
Isobutane (2-methyl propane)
CG,F,OHH
A3
2-4-0
0.51
2,500
6.0
800
(continued)
[F] TABLE 1103.1— continued
REFRIGERANT CLASSIFICATION, AMOUNT AND TLV-TWA
REFRIGERANT
CHEMICAL
FORMULA
CHEMICAL NAME OR BLEND
HAZARD
CATEGORIES^
REFRIGERANT
CLASSIFICATION
DEGREES
OF HAZARD''
[M] AMOUNT OF REFRIGERANT PER OCCUPIED SPACE
Pounds per
1,000 cubic
feet
ppm
g/m^"
TLV-TWA'
(ppm)
R-412A
zeotrope
R-22/3 18/1 42b (70/5/25)
CG,F,OHH
A2
—
—
R-413A
zeotrope
R-218/134a/600a (9/88/3)
CG,F,OHH
A2
—
—
—
—
—
R-414A
zeotrope
R-22/124/600a/142b (51/28.5/4/16.5)
CG,OHH
Al
—
R-414B
zeotrope
R-22/1 24/600a/142b (50/39/1 .5/9.5)
CG,OHH
Al
—
—
—
—
—
R-416A
zeotrope
R-134a/l 24/600 (59/39.5/1.5)
CG,OHH
Al
2-0-0^^
6
21,000
96
—
R-417A
zeotrope
R-125/134a/600 (45.5/50/3.5)
CG,OHH
Al
2-0-0^^
—
—
—
—
R-SOO'^
azeotrope
R-12/152a (73.8/26.2)
CG,OHH
Al
2-0-0'^
7.4
29,000
120
1,000
R-502«
azeotrope
R-22/1 15 (48.8/51.2)
CG,OHH
Al
2-0-0<^
10
35,000
160
1,000
R-503^
azeotrope
R-23/13 (40.1/59.9)
CG,OHH
Al
2-0-0'^
15
67,000
240
1,000
R-717
NH3
Ammonia
CG,C,F,OHH
B2
3-3-0''
0.022
500
0.35
25
R-718
H2O
Water
—
Al
0-0-0
—
—
—
R-744
CO2
Carbon dioxide
CG,OHH
Al
2-0-0^^
4.5
40,000
72
5,000
R-1150
CH2=CH2
Ethene (ethylene)
CG,F,OHH
A3
1-4-2
0.38
5,200
6.0
1,000
R-1270
CH3CH=CH2
Propene (propylene)
CG,F,OHH
B3
1-4-1
0.37
3,400
5.0
660
For SI: 1 pound = 0.454 kg, 1 cubic foot = 0.0283 m\
a. CG = Compressed gas; C = Corrosive; F = Flammable; OHH = Other Health Hazard.
b. Degrees of hazard are for health, fire, and reactivity, respectively, in accordance with NFPA 704.
c. Reduction to 1 -0-0 is allowed if analysis satisfactory to the code official shows that the maximum concentration for a rupture or full loss of refrigerant charge would not exceed the IDLH, considering both the
refrigerant quantity and room volume.
d. For installations that are entirely outdoors, use 3-1-0.
e. Class I ozone depleting substance; prohibited for new installations.
f. PEL or consistent occupational exposure limit on a time-weighted average (TWA) basis (unless noted C for ceiling) for an 8 hr/d and 40 hr/wk.
REFRIGERATION
5.3 System classificatiom. Refrigeration systems shall be
classified according to the degree of probability that refrigerant
leaked from a failed connection, seal, or component could
enter an occupied area. The distinction is based on the basic
design or location of the components.
ll®3.3ol Low-probability systems. Double-indirect
open-spray systems, indirect closed systems and indirect-
vented closed systems shall be classified as low-probability
systems, provided that all refrigerant-containing piping and
fittings are isolated when the quantities in Table 1 103.1 are
exceeded.
1103.3.2 High-probability systems. Direct systems and
indirect open-spray systems shall be classified as
high-probability systems.
Exception: An indirect open-spray system shall not be
required to be classified as a high-probability system if
the pressure of the secondary coolant is at all times (oper-
ating and standby) greater than the pressure of the refrig-
erant.
SECTION 1104
lYSTEftffl APPLICATION REQUIREMENTS
1.1 General. The refrigerant, occupancy and system clas-
sification cited in this section shall be determined in accor-
dance with Sections 1103.1, 1103.2 and 1103.3, respectively.
For refrigerant blends assigned dual classifications, as formu-
lated and for the worst case of fractionation, the classifications
for the worst case of fractionation shall be used.
1.2 Machinery room. Except as provided in Sections
1 104.2. 1 and 1 104.2.2, all components containing the refriger-
ant shall be located either outdoors or in a machinery room
where the quantity of refrigerant in an independent circuit of a
system exceeds the amounts shown in Table 1 1 03. 1 . For refrig-
erant blends not listed in Table 1103.1, the same requirement
shall apply when the amount for any blend component exceeds
that indicated in Table 1103.1 for that component. This
requirement shall also apply when the combined amount of the
blend components exceeds a limit of 69,100 parts per million
(ppm) by volume. Machinery rooms required by this section
shall be constructed and maintained in accordance with Sec-
tion 1 105 for Group Al and Bl refrigerants and in accordance
with Sections 1105 and 1106 for Group A2, B2, A3 and B3
refrigerants.
1 . Machinery rooms are not required for hsted equip-
ment and appliances containing not more than 6.6
pounds (3 kg) of refrigerant, regardless of the refrig-
erant' s safety classification, where installed in accor-
dance with the equipment's or appliance's listing and
the equipment or appliance manufacturer's installa-
tion instructions.
2. Piping in conformance with Section 1 107 is allowed
in other locations to connect components installed in
a machinery room with those installed outdoors.
1104.2.1 Institutional occupancies. The amounts shown
in Table 1 103.1 shall be reduced by 50 percent for all areas
of institutional occupancies except kitchens, laboratories,
and mortuaries. The total of all Group A2, B2, A3 and B3
refrigerants shall not exceed 550 pounds (250 kg) in occu-
pied areas or machinery rooms.
1104.2.2 Industrial occupancies and refrigerated rooms.
This section applies only to industrial occupancies and
refrigerated rooms for manufacturing, food and beverage
preparation, meat cutting, other processes and storage.
Machinery rooms are not required where all of the follow-
ing conditions are met:
1 . The space containing the machinery is separated from
other occupancies by tight construction with tight-fit-
ting doors.
2. Access is restricted to authorized personnel.
3. The floor area per occupant is not less than 100 square
feet (9.3 m^) where machinery is located on floor lev-
els with exits more than 6.6 feet (2012 mm) above the
ground. Where provided with egress directly to the
outdoors or into approved building exits, the mini-
mum floor area shall not apply.
4. Refrigerant detectors are installed as required for
machinery rooms in accordance with Section 1 105.5. I I
5. Surfaces having temperatures exceeding 800°F
(427°C) and open flames are not present where any
Group A2, B2, A3 or B3 refrigerant is used (see Sec-
tion 1104.3.4).
6. All electrical equipment and appliances conform to
Class 1, Division 2, hazardous location classification
requirements of NFPA 70 where the quantity of any
Group A2, B2, A3 or B3 refrigerant in a single inde-
pendent circuit would exceed 25 percent of the lower
flammability limit (LFL) upon release to the space.
7. All refrigerant-containing parts in systems exceeding
100 hp (74.6 kW) drive power, except evaporators
used for refrigeration or dehumidification; condens-
ers used for heating; control and pressure relief valves
for either; and connecting piping, shall be located
either outdoors or in a machinery room.
1104.3 Refrigerant restrictions. Refrigerant applications,
maximum quantities and use shall be restricted in accordance
with Sections 1 104.3.1 through 1 104.3.4.
1104.3.1 Air-conditioning for human comfort. In other
than industrial occupancies where the quantity in a single
independent circuit does not exceed the amount in Table
1 103. 1, Group B 1, B2 and B3 refrigerants shall not be used
in high-probability systems for air-conditioning for human
comfort.
1104.3.2 Nonindustrial occupancies. Group A2 and B2
refrigerants shall not be used in high-probability systems
where the quantity of refrigerant in any independent refrig-
erant circuit exceeds the amount shown in Table 1104.3.2.
Group A3 and B3 refrigerants shall not be used except
where approved.
Exception: This section does not apply to laboratories
where the floor area per occupant is not less than 100
square feet (9.3 m^).
90
2007 OREGON WlECHAhSICAL SPECIALTY CODE
REFRIGERATION
TABLE 1104.3.2
MAXIMUM PERMISSIBLE QUANTITIES OF REFRIGERANTS
TYPE OF REFRIGERATION SYSTEM
MAXIMUM POUNDS FOR VARIOUS OCCUPANCIES
Institutional
Assembly
Residential
All other occupancies
Sealed absorption system
In exit access
In adjacent outdoor locations
In other than exit access
6.6
3.3
22
6.6
3.3
22
6.6
Unit systems
In other than exit access
6.6
6.6
For SI: 1 pound = 0.454 kg.
1104.3.3 All occupancies. The total of all Group A2, B2,
A3 and B3 refrigerants other than R-717, ammonia, shall
not exceed 1,100 pounds (499 kg) except where approved.
1104.3.4 Protection from refrigerant decomposition.
Where any device having an open flame or surface tempera-
ture greater than 800°F (427°C) is used in a room containing
more than 6.6 pounds (3 kg) of refrigerant in a single inde-
pendent circuit, a hood and exhaust system shall be pro-
vided in accordance with Section 5 10. Such exhaust system
shall exhaust combustion products to the outdoors.
Exception: A hood and exhaust system shall not be
required:
1. Where the refrigerant is R-717, R-718, or R-744;
2. Where the combustion air is ducted from the out-
doors in a manner that prevents leaked refrigerant
from being combusted; or
3. Where a refrigerant detector is used to stop the
combustion in the event of a refrigerant leak (see
Sections 1105.5 and 1105.7).
1104.4 Volume calculations. Volume calculations shall be in
accordance with Sections 1104.4.1 through 1104.4.3.
1104.4.1 Noncommunicating spaces. Where the refriger-
ant-containing parts of a system are located in one or more
spaces that do not communicate through permanent open-
ings or HVAC ducts, the volume of the smallest, enclosed
occupied space shall be used to determine the permissible
quantity of refrigerant in the system.
1104.4.2 Communicating spaces. Where an evaporator or
condenser is located in an air duct system, the volume of the
smallest, enclosed occupied space served by the duct system
shall be used to determine the maximum allowable quantity
of refrigerant in the system.
Exception: If airflow to any enclosed space cannot be
reduced below one-quarter of its maximum, the entire
space served by the air duct system shall be used to deter-
mine the maximum allowable quantity of refrigerant in
the system.
1104.4.3 Plenums. Where the space above a suspended
ceiling is continuous and part of the supply or return air ple-
num system, this space shall be included in calculating the
volume of the enclosed space.
SECTION 1105
MACHINERY ROOM, GENERAL REQUIREMENTS
1105.1 Access. Access to machinery rooms shall be restricted
to authorized personnel. A sign shall be posted on the machin-
ery room door prohibiting access by others.
1105.2 Dimensions. A machinery room shall be dimensioned
so as to provide clearances required by Chapter 3. There shall
be clear head room of not less than 7 74 feet (2210 mm) below
equipment and appliances located over passageways.
1105.3 Doors. Each machinery room shall have self-closing,
weather-stripped doors opening in the direction of egress
travel. Doors and door openings shall comply with the require-
ments of the Building Code.
1105.4 Openings. Openings to other parts of the building that
permit passage of escaping refrigerant to other parts of the
building are prohibited. Ducts and air handlers in the machin-
ery room that operate at a lower pressure than the room shall be
sealed to prevent any refrigerant leakage from entering the
airstream.
Exceptions:
1 . Egress doors serving the machinery room.
2. Access doors and panels in air ducts and air-handling
units, provided that such openings are gasketed and
tight fitting.
1105.5 Refrigerant detector. Machinery rooms shall contain
a refrigerant detector with an audible and visual alarm. The
detector or a sampling tube that draws air to the detector shall
be located in an area where refrigerant from a leak will concen-
trate. The alarm shall be actuated at a value not greater than the
corresponding TLV-TWA values shown in Table 1103.1.
Detectors and alarms shall be placed in approved locations
Exception: Detectors are not required for ammonia system
complying with Section 1 106.8.
1105.6 Tests. Periodic tests of the mechanical ventilating sys-
tem shall be performed in accordance with manufacturer's
specifications and as required by the code official.
1105.7 Fuel-burning appliances. Fuel-burning appliances
and equipment having open flames and that use combustion air
from the machinery room shall not be installed in a machinery
room.
Exceptions:
1 . Where the refrigerant is carbon dioxide or water.
2007 OREGON MECHANICAL SPECIALTY CODE
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REFRIGERATION
2. Fuel-burning appliances shall not be prohibited in the
same machinery room with refrigerant-containing
equipment or appliances where combustion air is
ducted from outside the machinery room and sealed
in such a manner as to prevent any refrigerant leakage
from entering the combustion chamber, or where a
refrigerant vapor detector is employed to automati-
cally shut off the combustion process in the event of
refrigerant leakage.
ll<D5o8 Ventilation. Machinery rooms shall be mechanically
ventilated to the outdoors. Mechanical ventilation shall be
capable of exhausting the minimum quantity of air both at nor-
mal operating and emergency conditions. Multiple fans or
multispeed fans shall be allowed in order to produce the emer-
gency ventilation rate and to obtain a reduced airflow for nor-
mal ventilation.
Exceptiomi Where a refrigerating system is located out-
doors more than 20 feet (6096 mm) from any building open-
ing and is enclosed by a penthouse, lean-to or other open
structure, natural or mechanical ventilation shall be pro-
vided. Location of the openings shall be based on the rela-
tive density of the refrigerant to air. The free-aperture cross
section for the ventilation of the machinery room shall be
not less than:
F= 4g
For SI: F= 0.138 Vg
(Equation 11-1)
1105.8.4 Quantity — emergency conditions. Upon actua-
tion of the refrigerant detector required in Section 1105.5,
the mechanical ventilation system shall exhaust air from the
machinery room in the following quantity:
<2 = 1 00 X Vg (Equation 11-2)
For SI: Q = 0.07 x 4g
where:
Q = The airflow in cubic feet per minute (mVs).
G = The design mass of refrigerant in pounds (kg) in the
largest system, any part of which is located in the
machinery room.
1105.9 Termination of relief devices. Pressure rehef devices,
fusible plugs and purge systems located within the machiner>'
room shall terminate outside of the structure at a location not
less than 15 feet (4572 mm) above the adjoining grade level and
not less than 20 feet (6096 mm) from any window, ventilation
opening or exit.
1105.10 Ammonia discharge. Pressure relief valves for
ammonia systems shall discharge in accordance with
ASHRAE 15.
1105.11 Emergency pressure control system. Refrigeration
systems containing more than 6.6 pounds (3 kg) of flammable,
toxic or highly toxic refrigerant or ammonia shall be provided
with an emergency pressure control system in accordance with
Section 606.10 of the Fire Code.
where:
F = The free opening area in square feet (m^).
G = The mass of refrigerant in pounds (kg) in the largest
system, any part of which is located in the machinery
room.
1105.8.1 Discharge location. The discharge of the air shall
be to the outdoors in accordance with Chapter 5. Exhaust
from mechanical ventilation systems shall be discharged
not less than 20 feet (6096 mm) from a property line or
openings into buildings.
1105.8.2 Makeup air. Provisions shall be made for makeup
air to replace that being exhausted. Openings for makeup air
shall be located to avoid intake of exhaust air. Supply and
exhaust ducts to the machinery room shall serve no other
area, shall be constructed in accordance with Chapter 5 and
shall be covered with corrosion-resistant screen of not less
than V4-inch (6.4 mm) mesh.
1105.8.3 Quantity — normal ventilation. During occupied
conditions, the mechanical ventilation system shall exhaust
the larger of the following:
1. Not less than 0.5 cfm per square foot (0.0025 mVs •
m^) of machinery room area or 20 cfm (0.009 m^/s)
per person; or
2. A volume required to limit the room temperature rise
to 18°F (10°C) taking into account the ambient heat-
ing effect of all machinery in the room.
SECTION 1106
MACHINERY ROOM, SPECIAL REQUIREMENTS
j.l General, Where required by Section 1104.2, the
machinery room shall meet the requirements of this section in
addition to the requirements of Section 1105.
1106.2 Elevated temperature. There shall not be an open
flame-producing device or continuously operating hot surface
over 800°F (427°C) permanently installed in the room.
1106.3 Construction requirements. The machinery room
shall be separated from other occupied space with smoke-tight,
1-hour fire-resistance-rated construction.
1106.4 Opening protection. Opening protection between the
machinery room and other occupied spaces shall be approved,
self-closing, tight-fitting fire doors with a minimum fire-resis-
tance rating of '^/^ hour.
1106.5 Pipe penetrations. All pipe penetrations of the interior
walls, ceiling or floor of machinery rooms shall be sealed vapor
tight and protected in accordance with the Building Code.
1106.6 Exterior openings. Openings in exterior walls of
machinery rooms shall not be located under any exit, stairway
or exit discharge.
1106.7 Egress. Each machinery room shall be provided with a
minimum of one exit door that opens directly to the outside.
Exception: Self-closing, tight-fitting doors opening into a
vestibule leading directly outside.
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2007 OREGON MECHANICAL SPECIALTY CODE
REFRIGERATION
1106.8 Ammonia room ventilation. Ventilation systems in
ammonia machinery rooms shall lie operated continuously at
the emergency ventilation rate determined in accordance with
Section 1105.8.4.
Exceptions:
1 . Machinery rooms equipped with a vapor detector that
will automatically start the ventilation system at the
emergency rate determined in accordance with Sec-
tion 1 105. 8.4, and that will actuate an alarm at a detec-
tion level not to exceed 1-000 ppm; or
2. Machinery rooms conforming to the Class 1 , Division
2, hazardous location classification requirements of
NFPA 70.
1106.9 Flammable refrigerants. Where refrigerants of
Groups A2, A3, B2 and B3 are used, the machinery room shall
conform to the Class 1, Division 2, hazardous location classifi-
cation requirements of the Electrical Code.
Exception: Ammonia machinery rooms.
1106.10 Remote controls. Remote control of the mechanical
equipment and appliances located in the machinery room shall
be provided at an approved location immediately outside the
machinery room and adjacent to its principal entrance.
1106.10.1 Refrigeration system. A clearly identified
switch of the break- glass type shall provide off-only control
of electrically energized equipment and appliances in the
machinery room, other than refrigerant leak detectors and
machinery room ventilation.
Exception: In machinery rooms where only nonflam-
mable refrigerants are used, electrical equipment and
appliances, other than compressors, are not required to
be provided with a cutoff switch.
1106.10.2 Ventilation system. A clearly identified switch
of the break-glass type shall provide on-only control of the
machinery room ventilation fans.
1106.11 Emergency signs and labels. Refrigeration units and
systems shall be provided with approved emergency signs,
charts, and labels in accordance with the Fire Code.
SECTION 1107
REFRIGERANT PIPING
1107.1 General. All refrigerant piping shall be installed, tested
and placed in operation in accordance with this chapter.
1107.2 Pipe enclosures. Rigid or flexible metal enclosures or
pipe ducts shall be provided for soft, annealed copper tubing
and used for refrigerant piping erected on the premises and
containing other than Group Al or B 1 refrigerants. Enclosures
shall not be required for connections between condensing units
and the nearest riser box(es), provided such connections do not
exceed 6 feet (1829 mm) in length.
1107.3 Condensation. All refrigerating piping and fittings,
brine piping and fittings that, during normal operation, will
reach a surface temperature below the dew point of the sur-
rounding air, and are located in spaces or areas where conden-
sation will cause a safety hazard to the building occupants,
structure, electrical equipment or any other equipment or appli-
ances, shall be protected in an approved manner to prevent such
damage.
1107.4 Materials for refrigerant pipe and tubing. Piping
materials shall be as set forth in Sections 1107.4.1 through
1107.4.5.
1107.4.1 Steel pipe. Carbon steel pipe with a wall thickness
not less than Schedule 80 shall be used for Group A2, A3,
B2 or B3 refrigerant liquid lines for sizes 1.5 inches (38
mm) and smaller. Carbon steel pipe with a wall thickness
not less than Schedule 40 shall be used for Group Al or Bl
refrigerant liquid lines 6 inches (152 nmi) and smaller.
Group A2, A3, B2 or B3 refrigerant liquid lines sizes 2
inches (51 mm) through 6 inches (152 mm) and all refriger-
ant suction and discharge lines 6 inches (152 mm) and
smaller. Type F steel pipe shall not be used for refrigerant
lines having an operating temperature less than -20°F
(-29°C).
1107.4.2 Copper and brass pipe. Standard iron-pipe size,
copper and red brass (not less than 80-percent copper) pipe
shall conform to ASTM B 42 and ASTM B 43.
1107.4.3 Copper tube. Copper tube used for refrigerant
piping erected on the premises shall be seamless copper
tube of Type ACR (hard or annealed) complying with
ASTM B 280. Where approved, copper tube for refrigerant
piping erected on the premises shall be seamless copper
tube of Type K, L or M (drawn or annealed) in accordance
with ASTM B 88. Annealed temper copper tube shall not be
used in sizes larger than a 2-inch (51 mm) nominal size.
Mechanical joints shall not be used on annealed temper cop-
per tube in sizes larger than 7/8-inch (22.2 mm) OD size.
1107.4.4 Copper tubing joints. Copper tubing joints used
in refrigerating systems containing Group A2, A3, B2 or B3
refrigerants shall be brazed. Soldered joints shall not be
used in such refrigerating systems.
1107.4.5 Aluminum tube. Type 3003-0 aluminum tubing
with high-pressure fittings shall not be used with methyl
chloride and other refrigerants known to attack aluminum.
1107.5 Joints and refrigerant-containing parts in air ducts.
Joints and all refrigerant-containing parts of a refrigerating
system located in an air duct of an air-conditioning system car-
rying conditioned air to and from human-occupied space shall
be constructed to withstand, without leakage, a pressure of 150
percent of the higher of the design pressure or pressure relief
device setting.
1107.6 Exposure of refrigerant pipe joints. Refrigerant pipe
joints erected on the premises shall be exposed for visual
inspection prior to being covered or enclosed.
1107.7 Stop valves. All systems containing more than 6.6
pounds (3 kg) of a refrigerant in systems using positive-dis-
placement compressors shall have stop valves installed as fol-
lows:
I. At the inlet of each compressor, compressor unit or con-
densing unit.
2007 OREGON MECHANICAL SPECIALTY CODE
93
REFRIGERATION
2. At the discharge outlet of each compressor, compressor
unit or condensing unit and of each liquid receiver.
Exceptioms:
1. Systems that have a refrigerant pumpout function
capable of storing the entire refrigerant charge in a
receiver or heat exchanger.
2. Systems that are equipped with provisions for
pumpout of the refrigerant using either portable or
permanently installed recovery equipment.
3. Self-contained systems.
IJA Liquid receivers. All systems containing 100
pounds (45 kg) or more of a refrigerant, other than systems
utilizing nonpositive displacement compressors, shall have
stop valves, in addition to those required by Section 1 107.7,
on each inlet of each liquid receiver. Stop valves shall not be
required on the inlet of a receiver in a condensing unit, nor
on the inlet of a receiver which is an integral part of the con-
denser.
L12 Copper tubing. Stop valves used with soft
annealed copper tubing or hard-drawn copper tubing
Vg-inch (22.2 mm) OD standard size or smaller shall be
securely mounted, independent of tubing fastenings or sup-
ports.
1107,7,3 Identification, Stop valves shall be identified
where their intended purpose is not obvious. Numbers shall
not be used to label the valves, unless a key to the numbers is
located near the valves.
SECTION
FIELD TEST
1108,1 General, Every refrigerant-containing part of every
system that is erected on the premises, except compressors,
condensers, vessels, evaporators, safety devices, pressure
gauges and control mechanisms that are listed and factory
tested, shall be tested and proved tight after complete installa-
tion, and before operation. Tests shall include both the high-
and low-pressure sides of each system at not less than the lower
of the design pressures or the setting of the pressure relief
device(s). The design pressures for testing shall be those listed
on the condensing unit, compressor or compressor unit
name-plate, as required by ASHRAE 15.
Exceptions;
1 . Gas bulk storage tanks that are not permanently con-
nected to a refrigeration system.
2. Systems erected on the premises with copper tubing
not exceeding Vg-inch (15.8 mm) OD, with wall
thickness as required by ASHRAE 15, shall be tested
in accordance with Section 1108.1, or by means of
refrigerant charged into the system at the saturated
vapor pressure of the refrigerant at 70°F (21°C) or
higher.
3. Limited-charge systems equipped with a pressure
relief device, erected on the premises, shall be tested
at a pressure not less than one and one-half times the
pressure setting of the relief device. If the equipment
or appliance has been tested by the manufacturer at
one and one-half times the design pressure, the test
after erection on the premises shall be conducted at
the design pressure.
1108.1,1 Booster compressor. Where a compressor is used
as a booster to obtain an intermediate pressure and dis-
charges into the suction side of another compressor, the
booster compressor shall be considered a part of the low
side, provided that it is protected by a pressure relief device.
1108.. 1.2 Centrifugal/nonpositive displacement com-
pressors. In field-testing systems using centrifugal or other
nonpositive displacement compressors, the entire system
shall be considered as the low-side pressure for field test
purposes.
1108.2 Test gases. Tests shall be performed with an inert dried
gas including, but not limited to, nitrogen and carbon dioxide.
Oxygen, air, combustible gases and mixtures containing such
gases shall not be used.
Exception: The use of air is allowed to test R-717, ammo-
nia, systems provided that they are subsequently evacuated
before charging with refrigerant.
1108.3 Test apparatus. The means used to build up the test
pressure shall have either a pressure-limiting device or a pres-
sure-reducing device and a gauge on the outlet side.
1108.4 Declaration. A certificate of test shall be provided for
all systems containing 55 pounds (25 kg) or more of refriger-
ant. The certificate shall give the name of the refrigerant and the
field test pressure applied to the high side and the low. side of
the system. The certification of test shall be signed by the
installer and shall be made part of the public record.
<
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2007 OREGON MECHANICAL SPECIALTY CODE
CHAPTER 12
HYDRONIC PIPING
SECTION 1201
GENERAL
L.l Scope. The provisions of this chapter shall govern the
construction, installation, alteration and repair of hydronic pip-
ing systems. This chapter shall apply to hydronic piping sys-
tems that are part of heating, ventilation and air-conditioning
systems. Such piping systems shall include steam, hot water,
chilled water, steam condensate and ground source heat pump
loop systems. Potable cold and hot water distribution systems
shall be installed in accordance with the Plumbing Code.
1201.2 Pipe sizing. Piping for hydronic systems shall be sized
for the demand of the system.
SECTION 1202
MATERIAL
1202.1 Piping. Piping material shall conform to the standards
cited in this section.
Exception: Embedded piping regulated by Section 1209.
1202.2 Used materials. Reused pipe, fittings, valves or other
materials shall be clean and free of foreign materials and shall
be approved by the code official for reuse.
1202.3 Material rating. Materials shall be rated for the operat-
ing temperature and pressure of the hydronic system. Materials
shall be suitable for the type of fluid in the hydronic system.
1202.4 Piping materials standards. Hydronic pipe shall con-
form to the standards listed in Table 1202.4. The exterior of the
pipe shall be protected from corrosion and degradation.
TABLE 1202.4
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Acrylonitrile butadiene styrene
(ABS) plastic pipe
ASTM D 1527; ASTM D 2282
Brass pipe
ASTM B 43
Brass tubing
ASTM B 135
Copper or copper-alloy pipe
ASTM B 42; ASTM B 302
Copper or copper-alloy tube
(Type K, L or M)
ASTM B 75; ASTM B 88;
ASTM B 251
Chlorinated polyvinyl chloride
(CPVC) plastic pipe
ASTM D 2846; ASTM F 441;
ASTM F 442
Cross-linked polyethylene/
aluminum/cross-linked
polyethylene (PEX-AL-PEX)
pressure pipe
ASTM F 1281;
CSACAN/CSA-B-137.10
Cross-linked polyethylene
(PEX) tubing
ASTM F 876; ASTM F 877
TABLE 1202.4— continued
HYDRONIC PIPE
MATERIAL
STANDARD (see Chapter 15)
Lead pipe
FS WW-P-325B
Polybutylene (PB) plastic pipe
and tubing
ASTM D 3309
Polyethylene (PE) pipe, tubing
and fittings (for ground source
heat pump loop systems)
ASTM D 25 1 3 ; ASTM D 3035 ;
ASTM D 2447; ASTM D 2683;
ASTM F 1055; ASTM D 2837;
ASTM D 3350; ASTM D 1 693
Polyvinyl chloride (PVC)
plastic pipe
ASTM D 1785; ASTM D 2241
Steel pipe
ASTM A 53; ASTM A 106
Steel tubing
ASTM A 254
1202.5 Pipe fittings. Hydronic pipe fittings shall be approved
for installation with the piping materials to be installed, and
shall conform to the respective pipe standards or to the stan-
dards listed in Table 1202.5.
TABLE 1202.5
HYDRONIC PIPE FITTINGS
MATERIAL
STANDARD (see Chapter 15)
Brass
ASTM F 1974
Bronze
ASMEB 16.24
Copper and copper alloys
ASME B16.15; ASME B16.18;
ASMEB 16.22; ASMEB 16.23;
ASME B16.26; ASME B16.29
Gray iron
ASTM A 126
Malleable iron
ASMEB 16.3
Plastic
ASTM D 2466; ASTM D 2467;
ASTM D 2468; ASTM F 438;
ASTM F 439; ASTM F 877
Steel
ASME B16.5; ASME B16.9;
ASME B16.il; ASME B16.28;
ASTM A 420
1202.6 Valves. Valves shall be constructed of materials that are
compatible with the type of piping material and fluids in the
system. Valves shall be rated for the temperatures and pres-
sures of the systems in which the valves are installed.
1202.7 Flexible connectors, expansion and vibration com-
pensators. Flexible connectors, expansion and vibration con-
trol devices and fittings shall be of an approved type.
(continued)
2007 OREGON MECHANICAL SPECIALTY CODE
95
HYDRONIC PIPING
IECT80N 1203
S AND CONNECTIONS
1203,1 Approval. Joints and connections shall be of an
approved type. Joints and connections shall be tight for the
pressure of the hydronic system.
LI Joints between different piping materials.
Joints between different piping materials shall be made with
approved adapter fittings. Joints between different metallic
piping materials shall be made with approved dielectric fit-
tings or brass converter fittings.
12<D)3.2 Preparation of pipe ends. Pipe shall be cut square,
reamed and chamfered, and shall be free of burrs and obstruc-
tions. Pipe ends shall have full-bore openings and shall not be
undercut.
1203.3 Joint preparation and installation. When required by
Sections 1203.4 through 1203.14, the preparation and installa-
tion of brazed, mechanical, soldered, solvent-cemented,
threaded and welded joints shall comply with Sections
1203.3.1 through 1203.3.7.
1203.3.1 Brazed joints. Joint surfaces shall be cleaned. An
approved flux shall be applied where required. The joint
shall be brazed with a filler metal conforming to AWS A5.8.
1203.3.2 Mechanical joints. Mechanical joints shall be
installed in accordance with the manufacturer's instruc-
tions.
1203.3.3 Soldered joints. Joint surfaces shall be cleaned. A
flux conforming to ASTM B 813 shall be applied. The joint
shall be soldered with a solder conforming to ASTM B 32.
1203.3.4 Solvent-cemented Joints. Joint surfaces shall be
clean and free of moisture. An approved primer shall be
applied to CPVC and PVC pipe-joint surfaces. Joints shall
be made while the cement is wet. Solvent cement conform-
ing to the following standards shall be applied to all joint
surfaces:
1. ASTM D 2235 for ABS joints.
2. ASTM F 493 for CPVC joints.
3. ASTM D 2564 for PVC joints.
CPVC joints shall be made in accordance with ASTM D
2846.
5.3.5 Threaded joints. Threads shall conform to
ASME B 1 .20. 1 . Schedule 80 or heavier plastic pipe shall be
threaded with dies specifically designed for plastic pipe.
Thread lubricant, pipe -joint compound or tape shall be
applied on the male threads only and shall be approved for
application on the piping material.
1203.3.6 Welded joints. Joint surfaces shall be cleaned by
an approved procedure. Joints shall be welded with an
approved filler metal.
1203.3.7 Grooved and stoouldered meclnanical joints.
Grooved and shouldered mechanical joints shall conform to
the requirements of ASTM F 1476 and shall be installed in
accordance with the manufacturer's installation instruc-
tions.
1203.3.8 Mechanically formed tee fittings. Mechanically
extracted outlets shall have a height not less than three times
the thickness of the branch tube wall.
1203.3.8.1 Full flow assurance. Branch tubes shall not
restrict the flow in the run tube. A dimple/depth stop
shall be formed in the branch tube to ensure that penetra-
tion into the outlet is of the correct depth. For inspection
pui-poses, a second dimple shall be placed 0.25 inch (6.4
mm) above the first dimple. Dimples shall be aligned
with the tube run.
1203.3.8.2 Brazed joints. Mechanically formed tee fit-
tings shall be brazed in accordance with Section
1203.3.1.
1203.4 ABS plastic pipe. Joints between ABS plastic pipe or
fittings shall be solvent-cemented or threaded joints conform-
ing to Section 1203.3.
1203.5 Brass pipe. Joints between brass pipe or fittings shall
be brazed, mechanical, threaded or welded joints conforming
to Section 1203.3.
1203.6 Brass tubing. Joints between brass tubing or fittings
shall be brazed, mechanical or soldered joints conforming to
Section 1203.3.
1203.7 Copper or copper-alloy pipe. Joints between copper
or copper-alloy pipe or fittings shall be brazed, mechanical,
soldered, threaded or welded joints conforming to Section
1203.3.
1203.8 Copper or copper-alloy tubing. Joints between cop-
per or copper-alloy tubing or fittings shall be brazed, mechani-
cal or soldered joints conforming to Section 1203.3 or flared
joints conforming to Section 1203.8.1.
1203.8,1 Flared joints. Flared joints shall be made by a tool
designed for that operation.
1203.9 CPVC plastic pipe. Joints between CPVC plastic pipe
or fittings shall be solvent-cemented or threaded joints con-
forming to Section 1203.3.
1203.10 Polybutylene plastic pipe and tubing. Joints
between polybutylene plastic pipe and tubing or fittings shall
be mechanical joints conforming to Section 1203.3 or
heat-fusion joints conforming to Section 1203.10.1.
1203.10.1 Heat-fusion joints. Joints shall be of the
socket-fusion or butt-fusion type. Joint surfaces shall be
clean and free of moisture. Joint surfaces shall be heated to
melt temperatures and joined. The joint shall be undisturbed
until cool. Joints shall be made in accordance with ASTM D
3309.
1203.11 Cross-linked polyethylene (PEX) plastic tubing.
Joints between cross-linked polyethylene plastic tubing and fit-
tings shall conform to Sections 1203.11.1 and 1203.11.2.
Mechanical joints shall conform to Section 1203.3.
1203.11.1 Compression-type Ottings, When compres-
sion-type fittings include inserts and ferrules or 0-rings, the
fittings shall be installed without omitting the inserts and
ferrules or 0-rings.
1203.11.2 Plastic-to-metal connections. Soldering on the
metal jjortion of the system shall be performed at least 1 8
96
2007 OREGON MECHANICAL SPECIALTY CODE
HYDRONIC PIPING
inches (457 mm) from a plastic-to-metal adapter in the same
water line.
1203.12 PVC plastic pipe. Joints between PVC plastic pipe
and fittings shall be solvent-cemented or threaded joints con-
forming to Section 1203.3.
1203.13 Steel pipe. Joints between steel pipe or fittings shall
be mechanical joints that are made with an approved
elastomeric seal, or shall be threaded or welded joints conform-
ing to Section 1203.3.
1203.14 Steel tubing. Joints between steel tubing or fittings
shall be mechanical or welded joints conforming to Section
1203.3.
1203.15 Polyethylene plastic pipe and tubing for ground
source heat pump loop systems. Joints between polyethylene
plastic pipe and tubing or fittings for ground source heat pump
loop systems shall be heat fusion joints conforming to Section
1203.15.1, electrofusion joints conforming to Section
1203.15.2, or stab-type insertion joints conforming to Section
1203.15.3.
1203.15.1 Heat-fusion joints. Joints shall be of the
socket-fusion, saddle-fusion or butt-fusion type, fabricated
in accordance with the piping manufacturer's instructions.
Joint surfaces shall be clean and free of moisture. Joint sur-
faces shall be heated to melt temperatures and joined. The
joint shall be undisturbed until cool. Fittings shall be manu-
factured in accordance with ASTM D 2683.
1203.15.2 Electrofusion joints. Joints shall be of the
electrofusion type. Joint surfaces shall be clean and free of
moisture, and scoured to expose virgin resin. Joint surfaces
shall be heated to melt temperatures for the period of time
specified by the manufacturer. The joint shall be undis-
turbed until cool. Fittings shall be manufactured in accor-
dance with ASTM F 1055.
1203.15.3 Stab-type insert fittings. Joint surfaces shall be
clean and free of moisture. Pipe ends shall be chamfered and
inserted into the fittings to full depth. Fittings shall be manu-
factured in accordance with ASTM D 2513.
SECTION 1204
PIPE INSULATION
1204.1 Insulation characteristics. Pipe insulation installed in
buildings shall conform to the requirements of the Building
Code, shall be tested in accordance with ASTM E 84, using the
specimen preparation and mounting procedures of ASTM E
223 1 ; and shall have a maximum flame spread index of 25 and a
smoke-developed index not exceeding 450. Insulation installed
in an air plenum shall comply with Section 602.2.1.
Exception: The maximum flame spread index and smoke-
developed index shall not apply to one- and two-family
dwellings.
1204.2 Required thickness. Hydronic piping shall be insu-
lated to the thickness required by the Building Code.
SECTION 1205
VALVES
1205.1 Where required. Shutoff valves shall be installed in
hydronic piping systems in the locations indicated in Sections
1205.1.1 through 1205.1.6.
1205.1.1 Heat exchangers. Shutoff valves shall be
installed on the supply and return side of a heat exchanger.
Exception: Shutoff valves shall not be required when
heat exchangers are integral with a boiler; or are a com-
ponent of a manufacturer's boiler and heat exchanger
packaged unit and are capable of being isolated from the
hydronic system by the supply and return valves.
1205.1.2 Central systems. Shutoff valves shall be installed
on the building supply and return of a central utility system.
1205.1.3 Pressure vessels. Shutoff valves shall be installed
on the connection to any pressure vessel.
1205.1.4 Pressure-reducing valves. Shutoff valves shall
be installed on both sides of a pressure-reducing valve.
1205.1.5 Equipment and appliances. Shutoff valves shall
be installed on connections to mechanical equipment and
appliances. This requirement does not apply to components
of a hydronic system such as pumps, air separators, meter-
ing devices and similar equipment.
1205.1.6 Expansion tanks. Shutoff valves shall be
installed at connections to nondiaphragm-type expansion
tanks.
1205.2 Reduced pressure. A pressure relief valve shall be
installed on the low-pressure side of a hydronic piping system
that has been reduced in pressure. The relief valve shall be set at
the maximum pressure of the system design. The valve shall be
installed in accordance with Section 1008.
SECTION 1206
PIPING INSTALLATION
1206.1 General. Piping, valves, fittings and connections shall
be installed in accordance with the conditions of approval.
1206.1.1 Prohibited tee applications. Fluid in the supply
side of a hydronic system shall not enter a tee fitting through
the branch opening.
1206.2 System drain down. Hydronic piping systems shall be
designed and installed to permit the system to be drained.
Where the system drains to the plumbing drainage system, the
installation shall conform to the requirements of the Plumbing
Code.
1206.3 Protection of potable water. The potable water system
shall be protected from backflow in accordance with the
Plumbing Code.
1206.4 Pipe penetrations. Openings for pipe penetrations in
walls, floors or ceilings shall be larger than the penetrating
pipe. Openings through concrete or masonry building elements
shall be sleeved. The annular space surrounding pipe penetra-
tions shall be protected in accordance with the Building Code.
<
II
2007 OREGON MECHANICAL SPECIALTY CODE
97
HYDRONIC PIPING
>l I
1206.5 Clearance to combestibles. A pipe in a hydronic pip-
ing system in which the exterior temperature exceeds 250°F
(121°C) shall have a minimum clearance of 1 inch (25 mm) to
combustible materials.
1206.6 Contact with building material. A hydronic piping
system shall not be in direct contact with building materials
that cause the piping material to degrade or corrode, or that
interfere with the operation of the system.
1206.7 Water hammen The flow velocity of the hydronic pip-
ing system shall be controlled to reduce the possibility of water
hammer. Where a quick-closing valve creates water hammer,
an approved water-hammer arrestor shall be installed. The
arrestor shall be located within a range as specified by the man-
ufacturer of the quick-closing valve.
1206.8 Steam piping pitch. Steam piping shall be installed to
drain to the boiler or the steam trap. Steam systems shall not
have drip pockets that reduce the capacity of the steam piping.
5.9 Strains and stresses. Piping shall be installed so as to
prevent detrimental strains and stresses in the pipe. Provisions
shall be made to protect piping from damage resulting from
expansion, contraction and structural settlement. Piping shall
be installed so as to avoid structural stresses or strains within
building components.
1206,9.1 Flood hazard. Piping located in a flood hazard
area shall be capable of resisting hydrostatic and hydrody-
namic loads and stresses, including the effects of buoyancy,
during the occurrence of flooding to the design flood eleva-
tion.
1206.10 Pipe support. Pipe shall be supported in accordance
with Section 305.
1206.11 Condensation. Provisions shall be made to prevent
the formation of condensation on the exterior of piping.
SECTION 1207
TRANSFER FLUID
1207.1 Flash point. The flash point of transfer fluid in a
hydronic piping system shall be a minimum of 50°F (28°C)
above the maximum system operating temperature.
1207.2 Makeup water. The transfer fluid shall be compatible
with the makeup water supplied to the system.
SECTION 1208
TESTS
1208,1 General. Hydronic piping systems shall be tested
hydrostatically at one and one half times the maximum system
design pressure, but not less than 100 psi (689 kPa). The dura-
tion of each test shall be not less than 15 minutes.
Ground-source heat pump loop systems and cross-linked poly-
ethylene (PEX) tubing systems shall be tested in accordance
with Sections 1208.1.1 and 1208.1.2.
1208.1.1 Ground source heat pump loop systems. Before
connection (header) trenches are backfilled, the assembled
loop system shall be pressure tested with water at 100 psi
(689 kPa) for 30 minutes with no observed leaks. Flow and
pressure loss testing shall be performed and the actual flow
rates and pressure drops shall be compared to the calculated
design values. If actual flow rate or pressure drop values dif-
fer from calculated design values by more than 10 percent,
the problem shall be identified and corrected.
1208.1.2 Cross-linked polyethylene (PEX) tubing sys-
tems. Before a continuous looped systems using PEX tub-
ing is embedded or concealed, the assembled system shall
be pressure tested at 100 psi (689 kPa) for 30 minutes with
no observed leaks.
SECTION 1209
Piping for heating panels shall be stan-
dard-weight steel pipe, Type L copper tubing, cross-linked
polyethylene (PEX) tubing, cross-linked polyethylene/alumi-
num/cross-linked polyethylene (PEX-AL-PEX) pressure pipe
or polybutylene rated at 100 psi (689 kPa) at 180°F (82°C).
1209.2 Pressurizing during installation. Piping to be embed-
ded in concrete shall be pressure tested prior to pouring con-
crete. During pouring, the pipe shall be maintained at the
proposed operating pressure.
1209.3 Embedded joints. Joints of pipe or tubing that are
embedded in a portion of the building, such as concrete or plas-
ter, shall be in accordance with the requirements of Sections
1209.3.1 through 1209.3.5.
1209.3.1 Steel pipe joints. Steel pipe shall be welded by
electrical arc or oxygen/acetylene method.
1209.3.2 Copper tubing joints. Copper tubing shall be
joined by brazing with filler metals having a melting point
of not less than 1,000°F (538°C).
1209.3.3 Polybutylene joints. Polybutylene pipe and tub-
ing shall be installed in continuous lengths or shall be joined
by heat fusion in accordance with Section 1203.10.1.
1209.3.4 Cross-linked polyethylene joints. PEX pipe shall
be joined using cold expansion, insert or compression fit-
tings.
,5 Cross-linked polyet
linked polyethylene. PEX-AL-PEX pipe shall be joined by
mechanical, crimp/insert fittings.
1209.4 Not embedded related piping. Joints of other piping in
cavities or running exposed shall be joined by approved meth-
ods in accordance with manufacturer's installation instructions
and related sections of this code.
II
98
2007 OREGON WiECHANICAL SPECIALTY CODE
CHAPTER 13
FUEL OIL PIPING AND STORAGE
SECTION 1301
GENERAL
1301.1 Scope. This chapter shall govern the design, installa-
tion, construction and repair of fuel-oil storage and piping sys-
> terns.
1301.2 Storage and piping systems. Fuel-oil storage systems
shall comply with Section 603.3 of the Fire Code. Fuel-oil pip-
ing systems shall comply with the requirements of this code
I I and the Oregon Department of Environmental Quality (DEQ) .
1301.3 Fuel type. An appliance shall be designed for use with
the type of fuel to which it will be connected. Such appliance
shall not be converted from the fuel specified on the rating plate
for use with a different fuel without securing reapproval from
the code official.
1301.4 Fuel tanks, piping and valves. The tank, piping and
valves for appliances burning oil shall be installed in accor-
dance with the requirements of this chapter. When an oil burner
is served by a tank, any part of which is above the level of the
burner inlet connection and where the fuel supply line is taken
from the top of the tank, an approved antisiphon valve or other
siphon-breaking device shall be installed in lieu of the shutoff
valve.
1301.5 Tanks abandoned or removed. All exterior
above-grade fill piping shall be removed when tanks are aban-
doned or removed. Tank abandonment and removal shall be in
accordance with Section 3404.2.13 of the Fire Code.
SECTION 1302
MATERIAL
1302.1 General. Piping materials shall conform to the stan-
dards cited in this section.
1302.2 Rated for system. All materials shall be rated for the
operating temperatures and pressures of the system, and shall
be compatible with the type of liquid.
1302.3 Pipe standards. Fuel oil pipe shall comply with one of
the standards listed in Table 1302.3.
1302.4 Nonmetallic pipe. All nonmetallic pipe shall be listed
and labeled as being acceptable for the intended application for
flammable and combustible liquids. Nonmetallic pipe shall be
installed only outside, underground.
1302.5 Fittings and valves. Fittings and valves shall be
approved for the piping systems, and shall be compatible with,
or shall be of the same material as, the pipe or tubing.
1302.6 Bending of pipe. Pipe shall be approved for bending.
Pipe bends shall be made with approved equipment. The bend
shall not exceed the structural limitations of the pipe.
TABLE 1302.3
FUEL OIL PIPING
MATERIAL
STANDARD (see Chapter 15)
Brass pipe
ASTM B 43
Brass tubing
ASTMB 135
Copper or copper-alloy pipe
ASTM B 42; ASTM B 302
Copper or copper-alloy
tubing
(Type K, L or M)
ASTM B 75; ASTM B 88;
ASTM B 280
Labeled pipe
(See Section 1302.4)
Nonmetallic pipe
ASTM D 2996
Steel pipe
ASTM A 53; ASTM A 106
Steel tubing
ASTM A 254; ASTM A 539
1302.7 Pumps. Pumps that are not part of an appliance shall be
of a positive-displacement type. The pump shall automatically
shut off the supply when not in operation. Pumps shall be listed
and labeled in accordance with UL 343.
1302.8 Flexible connectors and hoses. Flexible connectors
and hoses shall be listed and labeled in accordance with UL
536.
SECTION 1303
JOINTS AND CONNECTIONS
1303.1 Approval. Joints and connections shall be approved
and of a type approved for fuel-oil piping systems. All threaded
joints and connections shall be made tight with suitable lubri-
cant or pipe compound. Unions requiring gaskets or packings,
right or left couplings, and sweat fittings employing solder
having a melting point of less than 1 ,000°F (538°C) shall not be
used in oil lines. Cast-iron fittings shall not be used. Joints and
connections shall be tight for the pressure required by test.
1303.1.1 Joints between different piping materials.
Joints between different piping materials shall be made with
approved adapter fittings. Joints between different metallic
piping materials shall be made with approved dielectric fit-
. tings or brass converter fittings.
1303.2 Preparation of pipe ends. All pipe shall be cut square,
reamed and chamfered and be free of all burrs and obstructions.
Pipe ends shall have full-bore openings and shall not be under-
cut.
1303.3 Joint preparation and installation. Where required
by Sections 1303.4 through 1303.10, the preparation and
installation of brazed, mechanical, threaded and welded joints
shall comply with Sections 1303.3.1 through 1303.3.4.
2007 OREGON MECHANICAL SPECIALTY CODE
99
FUEL OIL PDPDNG AND STORAGE
.3.1 Brazed joints. All joint surfaces shall be cleaned.
An approved flux shall be applied where required. The
joints shall be brazed with a filler metal conforming to AWS
A5.8.
5.3.2 Mechanical joints. Mechanical joints shall be
installed in accordance with the manufacturer's instruc-
tions.
Threads shall conform to
ASME B 1.20.1. Pipe-joint compound or tape shall be
applied on the male threads only.
.3.4 Welded joints. All joint surfaces shall be cleaned
by an approved procedure. The joint shall be welded with an
approved filler metal.
.4 Brass pipe. Joints between brass pipe or fittings shall
be brazed, mechanical, threaded or welded joints complying
with Section 1303.3.
5.5 Brass tubing. Joints between brass tubing or fittings
shall be brazed or mechanical joints complying with Section
1303.3.
1303.6 Copper or copper-alloy pipe. Joints between copper
or copper-alloy pipe or fittings shall be brazed, mechanical,
threaded or welded joints complying with Section 1303.3.
.7 Copper or copper-alloy tubing. Joints between cop-
per or copper-alloy tubing or fittings shall be brazed or
mechanical joints complying with Section 1303.3 or flared
joints. Flared joints shall be made by a tool designed for that
operation.
1303.8 Nonmetallic pipe. Joints between nonmetallic pipe or
fittings shall be installed in accordance with the manufacturer's
instructions for the labeled pipe and fittings.
pipe. Joints between steel pipe or fittings shall be
threaded or welded joints complying with Section 1303.3 or
mechanical joints complying with Section 1303.9.1.
1303,9.1 Mechanical joints. Joints shall be made with an
approved elastomeric seal. Mechanical joints shall be
installed in accordance with the manufacturer's instruc-
tions. Mechanical joints shall be installed outside, under-
ground, unless otherwise approved.
D) Steel tubing. Joints between steel tubing or fittings
shall be mechanical or welded joints complying with Section
1303.3.
1303.11 Piping protection. Proper allowance shall be made
for expansion, contraction, jarring and vibration. Piping other
than tubing, connected to underground tanks, except straight
fill lines and test wells, shall be provided with flexible connec-
tors, or otherwise arranged to permit the tanks to settle without
impairing the tightness of the piping connections.
1304.1 General. Pipe supports shall be in accordance with
Section 305.
SECTION 1305
FUEL OIL SYSTEM INSTALLATION
1305.1 Size. The fuel oil system shall be sized for the maxi-
mum capacity of fuel oil required. The minimum size of a sup-
ply Une shall be 3/8-inch (9.5 mm) inside diameter nominal
pipe or 3/8-inch (9.5 mm) OD tubing. The minimum size of a
return line shall be 1/4-inch (6.4 mm) inside diameter nominal
pipe or 5/16-inch (7.9 mm) outside diameter tubing. Copper
tubing shall have 0.035-inch (0.9 mm) nominal and 0.032-inch
(0.8 mm) minimum wall thickness.
1305.2 Protection of pipe, equipment and appliances. All
fuel oil pipe, equipment and appliances shall be protected from
physical damage.
1305.2.1 Flood hazard. All fuel oil pipe, equipment and
appliances located in flood hazard areas shall be located
above the design flood elevation or shall be capable of
resisting hydrostatic and hydrodynamic loads and stresses,
including the effects of buoyancy, during the occurrence of
flooding to the design flood elevation.
1305.3 Supply piping. Supply piping shall connect to the top
of the fuel oil tank. Fuel oil shall be supplied by a transfer pump
or automatic pump or by other approved means.
Exception: This section shall not apply to inside or
above-ground fuel oil tanks.
1305.4 Return piping. Return piping shall connect to the to
of the fuel oil tank. Valves shall not be installed on return pip
ing.
1305.5 System pressure. The system shall be designed for the
maximum pressure required by the fuel-oil-buming appliance.
Air or other gases shall not be used to pressurize tanks.
1305.6 Fill piping. A fill pipe shall terminate outside of a
building at a point at least 2 feet (610 mm) from any building
opening at the same or lower level. A fill pipe shall terminate in
a manner designed to minimize spilling when the filling hose is
disconnected. Fill opening shall be equipped with a tight metal
cover designed to discourage tampering.
1305.7 Vent piping. Liquid fuel vent pipes shall terminate out-
side of buildings at a point not less than 2 feet (610 mm) mea-
sured vertically or horizontally from any building opening.
Outer ends of vent pipes shall terminate in a weatherproof vent
cap or fitting or be provided with a weatherproof hood. AH vent
caps shall have a minimum free open area equal to the
cross-sectional area of the vent pipe and shall not employ
screens finer than No. 4 mesh. Vent pipes shall terminate suffi-
ciently above the ground to avoid being obstructed with snow
or ice. Vent pipes from tanks containing heaters shall be
extended to a location where oil vapors discharging from the
vent will be readily diffused. If the static head with a vent pipe
filled with oil exceeds 10 pounds per square inch (psi) (69 kPa),
the tank shall be designed for the maximum static head that will
be imposed.
Liquid fuel vent pipes shall not be cross connected with fill
pipes, lines from burners or overflow lines from auxiliary
tanks.
100
2007 OREGON MECHANICAL SPECIALTY CODE
FUEL OIL PIPING AND STORAGE
SECTION 1306
OIL GAUGING
1306.1 Level indication. All tanks in which a constant oil level
is not maintained by an automatic pump shall be equipped with
a method of determining the oil level.
1306.2 Test wells. Test wells shall not be installed inside build-
ings. For outside service, test wells shall be equipped with a
tight metal cover designed to discourage tampering.
1306.3 Inside tanks. The gauging of inside tanks by means of
measuring sticks shall not be permitted. An inside tank pro-
vided with fill and vent pipes shall be provided with a device to
indicate either visually or audibly at the fill point when the oil
in the tank has reached a predetermined safe level.
1306.4 Gauging devices. Gauging devices such as liquid level
indicators or signals shall be designed and installed so that oil
vapor will not be discharged into a building from the liquid fuel
supply system.
1306.5 Gauge glass. A tank used in connection with any oil
burner shall not be equipped with a glass gauge or any gauge
which, when broken, will permit the escape of oil from the
tank.
SECTION 1307
FUEL OIL VALVES
1307.1 Building shutoff. A shutoff valve shall be installed on
the fuel-oil supply line at the entrance to the building. Inside or
above-ground tanks are permitted to have valves installed at the
tank. The valve shall be capable of stopping the flow of fuel oil
to the building or to the appliance served where the valve is
installed at a tank inside the building.
1307.2 Appliance shutoff. A shutoff valve shall be installed at
the connection to each appliance where more than one
fuel-oil-buming appliance is installed.
1307.3 Pump relief valve. A relief valve shall be installed on
the pump discharge line where a valve is located downstream of
the pump and the pump is capable of exceeding the pressure
limitations of the fuel oil system.
1307.4 Fuel-oil heater relief valve. A relief valve shall be
installed on the discharge line of fuel-oil-heating appliances.
1307.5 Relief valve operation. The relief valve shall discharge
fuel oil when the pressure exceeds the limitations of the system.
The discharge line shall connect to the fuel oil tank.
SECTION 1308
TESTING
1308.1 Testing required. Fuel oil piping shall be tested in
accordance with NFPA 3 1 .
2007 OREGON MECHANICAL SPECIALTY CODE
101
1 02 2007 OREGON iViECHANJCAL SPECIALTY CODE
CHAPTER 14
SOLAR SYSTEMS
SECTION 1401
GENERAL
L.l Scope. This chapter shall govern the design, construc-
tion, installation, alteration and repair of systems, equipment
and appliances intended to utilize solar energy for nonpotable
space heating or cooling, swimming pool heating or process
heating.
L.2 Potable water supply. Potable water supplies to solar
systems shall be protected against contamination in accordance
with the Plumbing Code.
Exception: Where all solar system piping is a part of the
potable water distribution system, in accordance with the
requirements of the Plumbing Code, and all components of
the piping system are listed for potable water use, cross-con-
nection protection measures shall not be required.
.3 Heat exchangers. Heat exchangers used in domestic
water-heating systems shall be approved for the intended use.
The system shall have adequate protection to ensure that the
potability of the water supply and distribution system is prop-
erly safeguarded.
1401.4 Solar energy equipment and appliances. Solar
energy equipment and appliances shall conform to the require-
ments of this chapter and shall be installed in accordance with
the manufacturer's installation instructions.
L.S Bucts. Ducts utilized in solar heating and cooling sys-
tems shall be constructed and installed in accordance with
Chapter 6 of this code.
SECTION 1402
INSTALLATION
LI Access. Access shall be provided to solar energy equip-
ment and appliances for maintenance. Solar systems and
appurtenances shall not obstruct or interfere with the operation
of any doors, windows or other building components requiring
operation or access.
1402.2 Protection of equipment. Solar equipment exposed to
vehicular traffic shall be installed not less than 6 feet (1829 ,
mm) above the finished floor.
Exception: This section shall not apply where the equip-
ment is protected fi-om motor vehicle impact.
1402.3 Controlling condensation. Where attics or structural
spaces are part of a passive solar system, ventilation of such
spaces, as required by Section 406, is not required where other
approved means of controlling condensation are provided.
.4 Roof-mounted collectors. Roof-mounted solar collec-
tors that also serve as a roof covering shall conform to the
requirements for roof coverings in accordance with the Build-
ing Code.
Exception: The use of plastic solar collector covers shall be
limited to those approved plastics meeting the requirements
for plastic roof panels in the Building Code.
1402.4.1 Collectors mounted above the roof. When
mounted on or above the roof covering, the collector array
and supporting construction shall be constructed of
noncombustible materials or fire-retardant-treated wood
conforming to the Building Code to the extent required for
the type of roof construction of the building to which the
collectors are accessory.
Exception: The use of plastic solar collector covers shall
be limited to those approved plastics meeting the
requirements for plastic roof panels in the Building
Code.
1402.5 Equipment. The solar energy system shall be equipped
in accordance with the requirements of Sections 1402.5.1
through 1402.5.4.
1402.5.1 Pressure and temperature. Solar energy system
components containing pressurized fluids shall be protected
against pressures and temperatures exceeding design limi-
tations with a pressure and temperature relief valve. Each
section of the system in which excessive pressures are capa-
ble of developing shall have a relief device located so that a
section cannot be valved off or otherwise isolated from a
relief device. Relief valves shall comply with the require-
ments of the Plumbing Code and discharge in accordance
with Section 1008.
1402.5.2 Vacuum. The solar energy system components
that are subjected to a vacuum while in operation or during,
shutdown shall be designed to withstand such vacuum or
shall be protected with vacuum relief valves.
1402.5.3 Protection from freezing. System components
shall be protected from damage by freezing of heat transfer
liquids at the lowest ambient temperatures that will be
encountered during the operation of the system.
1402.5.4 Expansion tanks. Liquid single-phase solar
energy systems shall be equipped with expansion tanks
sized in accordance with Section 1007.
1402.6 Penetrations. Roof and wall penetrations shall be
flashed and sealed to prevent entry of water, rodents and
insects.
1402.7 Filtering. Air transported to occupied spaces through
rock or dust-producing materials by means other than natural
convection shall be filtered at the outlet from the heat storage
system.
SECTION 1403
HEAT TRANSFER FLUIDS
1403.1 Flash point. The flash point of the actual heat transfer
fluid utilized in a solar system shall be not less than 50°F
2007 OREGON MECHANICAL SPECIALTY CODE
103
SOLAR SYSTEWIS
(28°C) above the design maximum nonoperating (no-flow)
temperature of the fluid attained in the collector.
1403.2 Flammatole gases and Mqniids, A flammable liquid or
gas shall not be utilized as a heat transfer fluid. The flash point
of liquids used in occupancies classified in Group H or F shall
not be lower unless approved.
^TION 1
WE
LI Collectors. Factory-built collectors shall be listed and
labeled, and bear a label showing the manufacturer's name and
address, model number, collector dry weight, collector maxi-
mum allowable operating and nonoperating temperatures and
pressures, minimum allowable temperatures and the types of
heat transfer fluids that are compatible with the collector. The
label shall clarify that these specifications apply only to the col-
lector.
L2 Thermal storage emits. Pressurized thermal storage
units shall be listed and labeled, and bear a label showing the
manufacturer's name and address, model number, serial num-
ber, storage unit maximum and minimum allowable operating
temperatures, storage unit maximum and minimum allowable
operating pressures and the types of heat transfer fluids com-
patible with the storage unit. The label shall clarify that these
specifications apply only to the thermal storage unit.
104 2007 OREGON MECHANICAL SPECIALTY CODE
CHAPTER 15
REFERENCED STANDARDS
This chapter Usts the standards that are referenced in various sections of this document. The standards are listed herein by the pro-
mulgating agency of the standard, the standard identification, the effective date and title, and the section or sections of this document
that reference the standard. The application of the referenced standards shall be as specified in Section 102.8.
ACCA
Air Conditioning Contractors of America
1712 New Hampshire Ave, NW
Washington, DC 20009
Standard
Reference
Number
Title
Referenced
in code
section number
Manual D— 95
Residential Duct Systems 603.2
ANSI
American National Standards Institute
1 1 West 42nd Street
New York, NY 10036
Standard
reference
number
Title
Referenced
in code
section number
Z2 1.8— 1994
Installation of Domestic Gas Conversion Burners
919.1
Z21.83— 1998
Fuel Cell Power Plants
924.1
ARI
Air-Conditioning and Refrigeration Institute
Suite 425
4301 North Fairfax Drive
Arlington, VA 22203
Standard
Reference
Number
Title
Referenced
in code
section number
700—95
Specifications for Fluorocarbon and Other Refrigerants 1 102.2.2.3
ASHRAE
ASHRAE— 2001
15—2001
34—2001
62—2001
American Society of Heating, Refrigerating
and Air-Conditioning Engineers, Inc.
1791 Tullie Cu-cle, NE
Atlanta, GA 30329-2305
Title
ASHRAE Fundamentals Handbook— 2001 603.2
Safety Standard for Refrigeration Systems 1101.6, 1105.8, 1108.1
Designation and Safety Classification of Refrigerants 202, 1 102.2.1, 1 103.1
Ventilation for Acceptable Indoor Air Quality 401.1
Standard
-
Referenced
Reference
in code
Number
Title
section number
ASME
B 1. 20. 1—1 983 (R 1999)
B 16.3— 1999
B 16.5— 1996
B 16.9— 1993
B16.il— 1996
American Society of Mechanical Engineers
Three Park Avenue
New York, NY 10016-5990
Title
Pipe Threads, General Purpose (Inch) 1203.3.5, 1303.3.3
Malleable Iron Threaded Fittings, Classes 150 300 Table 1202.5
Pipe Flanges and Flanged Fittings NPS Vi through NPS 24— With B 16.5a- 1998 Addenda Table 1202.5
Factory Made Wrought Steel Buttwelding Fittings Table 1202.5
Forged Fittings, Socket- Welding and Threaded Table 1202.5
Standard
Referenced
Reference
in code
Number
Title
section number
2007 OREGON MECHANICAL SPECIALTY CODE
105
REFERENCED STANDARDS
B16.15— 1985(R1994)
B16.18— 1984(R1994)
B 16.22— 1995
B 16.23— 1992
B 16.24— 1991 {R1998)
B16.26— 1988
B 16.28— 1994
B 16.29— 1994
ASME— continued
Cast Bronze Threaded Fittings Table 1202.5
Cast Copper Alloy Solder Joint Pressure Fittings 513.13.1, Table 1202.5
Wrought Copper and Copper Alloy Solder Joint Pressure
Fittings— with B 16.22a- 1998 Addenda 513.13.1, Table 1202.5
Cast Copper Alloy Solder Joint Drainage Fittings DWV Table 1202.5
Cast Copper Alloy Pipe Flanges and Flanged Fittings: Class 150, 300, 400, 600, 900, 1500 and 2500 Table 1202.5
Cast Copper Alloy Fittings for Flared Copper Tubes Table 1202.5
Wrought Steel Buttwelding Short Radius Elbows and Returns Table 1202.5
Wrought Copper and Wrought Copper Alloy Solder Joint Drainage Fittings-DWV Table 1202.5
ASSE
American Society of Sanitary Engineering
28901 Clemens Road, Suite A
Westlake, OH 44145
Standard
Reference
Number
Title
Referenced
in code
section number
1017—99
Performance Requirements for Temperature Actuated Mixing Values
for Hot Water Distiibution Systems
.1002.2.2
ASTM
ASTM International
100 Barr Harbor Drive
West Conshohocken, PA 19428
Standard
Referenced
Reference
in code
Number
Tide
section number
A 53/A 53M— 01
A 106— 99el
A 126—01
A 254—97
A420/A420M— 01
A 539—99
B32— 00
B 42—98
B 43—98
B 68—99
B 75—99
B 88— 99el
B 135—00
B 251—97
B 280— 99el
B 302—00
B 813— OOeOl
C 315—00
C 41 1—97
D56— 01
D93— 00
D 1527—99
D 1693—01
D 1785—99
D 2235—01
D 2241—01
D 2282—99
D 24 12— 96a
D 2447—99
D 2466—01
Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated Welded
and Seamless Table 1202.4, Table 1302.3
Specification for Seamless Carbon Steel Pipe for High-Temperature Service Table 1202.4, Table 1302.3
Specification for Gray Iron Castings for Valves, Flanges, and Pipe Fittings Table 1202.5
Specification for Copper Brazed Steel Tubing Table 1202.4, Table 1302.3
Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for
Low-Temperature Service Table 1202.5
Specification for Electric-Resistance- Welded Coiled Steel Tubing for Gas and Fuel Oil Lines Table 1302.3
Specification for Solder Metal 1203.3.3
Specification for Seamless Copper Pipe, Standard Sizes 513.13.1, 1107.4.2, Table 1202.4, Table 1302.3
Specification for Seamless Red Brass Pipe, Standard Sizes 513.13.1, 1107.4.2, Table 1202.4, Table 1302.3
Specification for Seamless Copper Tube, Bright Annealed 513.13.1
Specification for Seamless Copper Tube Table 1202.4, Table 1302.3
Specification for Seamless Copper Water Tube . . 513.13.1, 1107.4.3, Table 1202.4, Table 1302.3
Specification for Seamless Brass Tube Table 1202.4, Table 1302.3
Specification for General Requirements for Wrought Seamless Copper and Copper- Alloy Tube 513.13.1, Table 1202.4
Specification for Seamless Copper Tube for Air Conditioning and Refrigeration
Field Service 513.13.1, 1107.4.3, Table 1302.3
Specification for Threadless Copper Pipe, Standard Sizes Table 1202.4, Table 1302.3
Specification for Liquid and Paste Fluxes for Soldering of Copper and Copper Alloy Tube 1203.3.3
Specification for Clay Flue Linings 801.16.1, Table 803.10.4
Test Method for Hot-Surface Performance of High-Temperature Thermal Insulation 604.3
Test Method for Flash Point by Tag Closed Tester 202
Test Method for Flash Point of Pensky-Martens Closed Cup Tester 202
Specification for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe,
Schedules 40 and 80 Table 1202.4
Test Method for Environmental Stress-Cracking of Ethylene Plastics Table 1202.4
Specification for Poly (Vinyl Chloride)(PVC) Plastic Pipe, Schedules 40, 80 and 120 Table 1202.4
Specifications for Solvent Cement for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe and Fittings 1203.3.4
Specification for Poly (Vinyl Chloride)(PVC) Pressure-Rated Pipe (SDR-Series) Table 1202.4
Specification for Acryloniti-ile-Butadiene-Styrene (ABS) Plastic Pipe (SDR-PR) Table 1202.4
Test Method for Determination of External Loading Characteristics of Plastic Pipe by
Parallel-Plate Loading 603.8.3
Specification for Polyethylene (PE) Plastic Pipe, Schedules 40 and 80, Based on Outside Diameter Table 1202.4
Specification for Poly (Vinyl Chloride)(PVC) Plastic Pipe Fittings, Schedule 40 Table 1202.5
•
106
2007 OREGON MECHANICAL SPECIALTY CODE
REFERENCED STANDARDS
D 2467—01
D 2468— 96a
D 2513-00
D 2564— 96a
D 2683—98
D 2837— 98a
D 2846/D 2846M— 99
D 2996—00
D 3035—01
D3278— 96el
D 3309— 96a
D 3350— 01
E 84—01
E119— OOe
E 136— 99e01
E 814— 00
F 438— 01
F 439—01
F441/F441M— 99
F 442/F 442M— 99
F 493—97
F 876— 01
F 877—01
F 1055—98
F 1281— 01
F 1974— OOe
ASTM — continued
Specification for Poly (Vinyl Chloride)(PVC) Plastic Pipe Fittings, Schedule 80 Table 1202.5
Specification fpr Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe Fittings, Schedule 40 Table 1202.5
Specification for Thermoplastic Gas Pressure Pipe, Tubing, and Fittings Table 1202.4, 1203.15.3
Specification for Solvent Cements for Poly (Vinyl Chloride) (PVC) Plastic Piping Systems 1203.3.4
Specification for Socket-Type Polyethylene Fittings for Outside Diameter-Controlled
Polyethylene Pipe and Tubing Table 1202.4, 1203.15.1
Test Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials Table 1202.4
Specification for Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Hot and Cold Water
Distribution Systems Table 1202.4, 1203.3.4
Specification for Filament- Wound Fiberglass (Glass Fiber Reinforced Thermosetting Resin) Pipe Table 1302.3
Specification for Polyethylene (PE) Plastic Pipe (DR-PR) Based on Controlled Outside Diameter Table 1202.4
Test Methods for Flash Point of Liquids by Small Scale Closed-Cup Apparatus 202
Specification for Polybutylene (PB) Plastic Hot- and Cold- Water Distribution Systems Table 1202.4, 1203.10.1
Specification for Polyethylene Plastics Pipe and Fittings Materials Table 1202.4
Test Method for Surface Burning Characteristics of Building Materials 202, 510.8, 602.2.1, 602.2.1.5,
604.3, 1204.1
Test Method for Fire Tests of Building Construction and Materials 607.5.2, 607.6.2
Test Method for Behavior of Materials in a Vertical Tube Furnace at 750°C 202
Test Method for Fire Tests of Through-Penetration Fire Stops 506.3. 10
Specification for Socket Type Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Pipe
Fittings, Schedule 40 Table 1202.5
Specification for Socket Type Chlorinated Poly (Vmyl Chloride) (CPVC) Plastic Pipe
Fittings, Schedule 80 Table 1202.5
Specification for Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Pipe,
Schedules 40 and 80 Table 1202.4
Specification for Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Pipe (SDR-PR) Table 1202.4
Specification for Solvent Cements for Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic
Pipe and Fittings 1203.3.4
Specification for Crosslinked Polyethylene (PEX) Tubing .Table 1202.4
Specification for Crosslinked Polyethylene (PEX) Plastic Hot and Cold- Water
Distribution Systems Table 1202.4, Table 1202.5
Specification for Electrofusion Type Polyethylene Fittings for Outside Diameter
Controlled Polyethylene Pipe and Tubing .Table 1202.4, 1203.15.2
Specification for Crosslinked Polyethylene/ Aluminum/Crosslinked Polyethylene
(PEX-AL-PEX) Pressure Pipe Table 1202.4
Standard Specification for Metal Insert Fittings for Polyethylene/Aluminum/Polyethylene
and Crosslinked Polyethylene/Aluminum/Crosshnked Polyethylene Composite Pressure Pipe Table 1202.5
AWS
American Welding Society
550 N.W LeJeune Road
P.O. Box 351040
Miami, FL 33135
Standard
Reference
Number
Title
Referenced
in code
section number
A5.8— 92
Specifications for Filler Metals for Brazing and Braze Welding 1203.3.1, 1303.3.1
CSA
Canadian Standards Association
178 Rexdale Blvd.
Rexdale (Toronto), Ontario, Canada M9W 1R3
Standard
Reference
Number
Tide
Referenced
in code
section number
CAN/CSA B137.10M— 99 Crosslinked Polyethylene/ Aluminum/Polyethylene Composite Pressure Pipe Systems Table 1202.4
2007 OREGON MECHANICAL SPECIALTY CODE
107
REFERENCED STANDARDS
International Institute of Ammonia Refrigeration
Suite 700
1101 Connecticut Ave., NW
Washington, DC 20036
Standard
Reference
Number
Tide
Referenced
in code
section number
2—99
Equipment, Design, and Installation of Ammonia Mechanical Refrigerating Systems 1101.6
Manufacturers Standardization Society of the Valve Fittings Industry, Inc.
127 Park Street, N.E.
Vienna, VA 22180
Standard
Reference
Number
Title
Referenced
in code
section number
SP-69— 1996
Pipe Hangers and Supports — Selection and Application 305.4
North American Insulation Manufacturers Association
Suite 310
44 Canal Center Plaza
Alexandria, VA 22314
Standard
Reference
Number
Title
Referenced
in code
section number
AH116— 02
Fibrous Glass Duct Construction Standards 603.5, 603.9
12—00
13—99
16—99
17—98
17 A— 98
31—01
37—98
58—01
69—97
72—99
82—99
91—99
211—00
262—99
704—96
853—00
National Fire Protection Association
Batterymarch Park
Quincy, MA 02269
Standard
Referenced
Reference
in code
Number
Title
section number
Carbon Dioxide Extinguishing Systems 509.2
Installation of Sprinkler Systems 509.2
Installation of Foam- Water Sprinkler Systems and Foam- Water Spray Systems 509.2
Dry Chemical Extinguishing Systems 509.2
Wet Chemical Extinguishing Systems 509.2
Installation of Oil-Burning Equipment 801.2.1, 801.18.1, 801.18.2, 920.2, 922.1, 1308.1
Stationary Combustion Engines and Gas Turbines 915.1 , 915.2
Liquefied Petroleum Gas Code 502.9.10
Explosion Prevention Systems 510.8.3
National Fire Alarm Code 606.3
Incinerators and Waste and Linen Handling Systems and Equipment 601.1
Exhaust Systems for Air Conveying of Vapors, Gases, Mists, and Noncombustible Particulate Solids 502.9.5. 1, 502.17
Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances 806. 1
Standard Method of Test for Flame Travel and Smoke of Wires and Cables for Use in Air-Handling Spaces 602.2.1.1
Identification of the Hazards of Materials for Emergency Response 502.8.4, Table 1 103. 1 , 5 10. 1
Installatin of Stationary Fuel Power Plants .924. 1
Sheet Metal Air Conditioning Contractors National Assoc, Inc.
4021 Fafayette Center Road
Chantilly, VA 22021
Standard
Reference
Number
Title
Referenced
in code
section number
SMACNA— 95
SMACNA— 92
HVAC Duct Construction Standards — Metal and Flexible.
Fibrous Glass Duct Construction Standards
.603.4
.603.5
108
2007 OREGON MECHANICAL SPECIALTY CODE
REFERENCED STANDARDS
•
UL
Underwriters Laboratories, Inc.
333 Pfingsten Road
Northbrook, IL 60062-2096
Standard
Referenced
Reference
in code
Number
Title
section number
17—94
103—98
127—96
181—96
181 A— 94
18 IB— 95
197—93
207—93
300—96
343—97
391—95
412—93
471—95
536—97
555—99
555C— 96
555S— 99
586—96
641—95
710—95
726—98
727—94
729—98
730—98
731—95
737—96
762—99
867—00
896—93
900—94
959—01
1240—94
1261—96
1482—98
1777—98
1820—97
1887—96
1995—98
2043—96
2158—97
2162—94
Vent or Chimney Connector Dampers for Oil-Fired Appliances — with Revisions through September 1998 803.6
Factory-Built Chimneys, Residential Type and Building Heating Appliance — with
Revisions through March 1999 805.2
Factory-Built Fireplaces— with Revisions through November 1999 805.3, 903.1, 903.3
Factory-made Air Ducts and Air Connectors — with Revisions through December 1998 512.2, 603.5, 603.6.1,
603.6.2, 603.9.1.1, 603.9.1.2, 603.9.1.3, 604.13
Standard for Closure Systems for use with Rigid Air Ducts and Air Connectors 603.9.1.1
Standard for Closure Systems for use with Flexible Air Ducts and Air Connectors 603.9.1.2, 603.9.1.3
Commercial Electric Cooking Appliances — With Revisions Through January 2000 507. 1
Refrigerant-Containing Components and Accessories, Nonelectrical — with Revisions through October 1997 1101.2
Fire Extinguishing Systems for Protection of Restaurant Cooking Areas, Fire Testing of 508.2
Pumps for Oil-Burning Appliances- with revisions through December 22, 1999 1302.7
Solid-Fuel and Combination-Fuel Central and Supplementary Furnaces — with Revisions through May 1999 918.1
Refrigeration Unit Coolers — with Revisions through November 1998 1 101.2
Cornmercial Refrigerators and Freezers — with Revisions through April 1998 1 101.2
Flexible metallic Hose - with revisions through October 2000 1302.8
Fire Dampers - with Revisions through October, 2000 607.3
Ceiling Dampers 607.3, 607.6.2
Smoke Dampers— with Revisions through December 1999 607.3, 607.3.1.1
High-Efficiency, Particulate, Air Filter Units - with revisions through april 21, 2000 605.2
Type L Low-Temperature Venting Systems — with Revisions through April 1999 802.1
Exhaust Hoods for Commercial Cooking Equipment-with Revisions through April 1999 507.1
Oil-Fired Boiler Assemblies — with Revisions through January 1999 916.1
Oil-Fired Centeral Furnaces — with Revisions through January 1999 918.1
Oil-Fired Floor Furnaces — with Revisions through January 1999 910.1
Oil-Fired Wall Furnaces — with Revisions through January 1999 909.1
Oil-Fired Unit Heaters — with Revisions through January 1999 920.1
Fireplace Stoves — with Revisions through January 2000 805.2, 905.1
Outline of Investigation for Power Ventilators for Restaurant Exhaust Appliances 506.5.1
Electrostatic Air Cleaners 605.2
Oil-Burning Stoves — with Revisions through November 1999 917.1, 922.1
Air Filter Units - with revisions through October 1999 605.2
Medium Heat Appliance Factory-Built Chimneys 805.5
Electric Commercial Clothes Drying Equipment — with Revisions through October 1999 913.1
Electric \yater Heaters for Pools and Tubs - with revisions through November 25, 1998 916.1
Solid-Fuel Type Room Heaters— with Revisions through January 2000 905.1
Chimney Liners — with Revisions through July 1998 801.18.4
Fire Test of Pneumatic Tubing for Flame and Smoke Characteristics - with Revisions
through March 1999 602.2.1.3
Fire Tests of Plastic Sprinkler Pipe for Visible Flame and Smoke Characteristics —
with Revisions through June 1999 602.2.1.2
Heating and Cooling Equipment - with Revisions through August 1999 911.1, 918.1, 918.3, 1101.2
Fire Test for Heat and Visible Smoke Release for Discrete Products and their
Accessories Installed in Air-Handling Spaces-With Revisions through February 1998 602.2.1.4
Outline of Investigation Electric Clothes Dryer — with Revisions through February 1999 913.1
Outline of Investigation for Commercial Wood-Fired Baking Ovens — Refractory Type 917.1
2007 OREGON MECHANICAL SPECIALTY CODE
109
110 2007 OREGON WiECHANlCAL SPECIALTY CODE
APPENDIX A
COMBUSTION AIR OPENINGS AND
CHIMNEY CONNECTOR PASS-THROUGHS
Not adopted by the State of Oregon
Figures A-1 through A-4 are illustrations of appliances located in confined spaces.
/■CHIMNEY OR VENT
For SI: 1 square inch = 645 mm , 1 British thermal unit per hour = 0.2931 W.
FIGURE A-1
ALL AIR FROM INSIDE THE BUILDING
NOTE: Each opening shall have a free area of not less than 1 square inch per 1 ,000 Btu per hour of the total input rating of all appli-
ances in the enclosure and not less than 100 square inches.
rCHIMNEYORVENT
ALTERNATE
AIR INLET— •
-ATTIC VENTILATION
(EACH END OF ATTIC)
FURNACE WATER
HEATER
a
INLET
AIR
A
-CRAWL SPACE
VENTILATION
For SI: 1 square inch = 645 mm^, 1 British thermal unit per hour = 0.293 1 W.
FIGURE A-2
ALL AIR FROM OUTDOORS— INLET AIR FROM VENTILATED CRAWL SPACE AND OUTLET AIR TO VENTILATED ATTIC
NOTE: The inlet and and outlet air openings shall each have a free area of not less than 1 square inch per 4,000 Btu per hour of the
total input rating of all appliances in the enclosure.
2007 OREGON MECHANICAL SPECIALTY CODE
111
APPENDIX A
rCHIMNEYORVENT
-ATTIC VENTILATION
(EACH END OF ATTIC)
INLET AIR DUCT
(ENDS 1 FOOT ABOVE FLOOR)
lU
For SI: 1 foot = 304.8 mm, 1 square inch = 645 mrr^, 1 British thermal unit per hour = 0.2931 W.
FIGURE A-3
ALL AIR FROM OUTDOORS THROUGH VENTILATED ATTIC
NOTE: The inlet and outlet air openings shall each have a free area of not less than 1 square inch per 4,000 Btu per hour of the total
input rating of all appliances in the enclosure.
rCHIMNEYORVENT
For SI: 1 foot = 304.8 mm, 1 square inch = 645 mm^, 1 British thermal unit per hour = 0.2931 W.
FIGURE A-4
ALL AIR FROWl OUTDOORS THROUGH HORIZONTAL DUCTS OR DIRECT OPENINGS
NOTE: Each air duct opening shall have a free area of not less than 1 square inch per 2,000 Btu per hour of the total input rating of all
appliances in the enclosure. If the appliance room is located against an outside wall and the air openings communicate directly with
the outdoors, each opening shall have a free area of not less than 1 square inch per 4,000 Btu per hour or the total input rating of all
appliances in the enclosure.
112
2007 OREGON MECHANJCAL SPECIALTY CODE
APPENDIX A
SYSTEM A
FIRE-CLAY LINER
2" MIN. CHIMNEY CLEARANCE
TO BRICK AND COMBUSTIBLE
MATERIALS.
MIN. CLEARANCE:
12" OF BRICK
CHIMNEY CONNECTOR
FIRE-CLAY LINER
LJ ^^^^3 1/2" THICK BRICK
MASONRY CHIMNEY
12" MIN. TO COMBUSTIBLES-"
["-INSOLUiLE
FRACTORY CEMENT
CHIMNEY SECTION
FLUSH WITH INSIDE
OF FLUE
2" mm. QHMHEr clearanc
FROM MASONRY TO SHEET
SUPPORTS AND COMBUSTIi
MATERIALS.
CHIMNEY CONNECTOR
CHIMNEY SECTION MANUFACTURER'S
PARTS SHALL BE UTIUZED TO ATTACH
CONNECTOR TO CHIMNEY SECTION.
LABELED. SOUD-INSUUTED. FACTORY^
BUILT CHIMNEY SECTION
SHEU STEEL SUPPORTS
FACTORY ->BUILT
CHIMNEY SECTION
AIR SPACE
For SI: 1 inch = 25.4 mm.
FIGURE A-5
CHIMNEY CONNECTOR SYSTEMS
2007 OREGON MECHANICAL SPECIALTY CODE
113
APPENDIX A
OH ©Fl".
Iky
T© SHErr iTlEEL
e©£y3iUSTiiLE Ci;3ATEilALS
OLASS=FiiE^ Bii^SyiLATi©!;^
r
(24
MASONRY
;ysti
For SI: 1 inch = 25.4 mm.
FIGURE A-5— continued
CHDlViNEY CONNECTOR SYSTEMS
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIXB
RECOMMENDED PERMIT FEE SCHEDULE
(Not adopted by the State of Oregon)
B101
MECHANICAL WORK, OTHER THAN GAS PIPING SYSTEMS
BlOl.l Initial Fee
For issuing each permit $_
B101.2 Additional Fees
BlOl.2.1 Fee for inspecting heating, ventilating, ductwork, air-conditioning, exhaust, venting, combustion air, pressure vessel,
solar, fuel oil and refrigeration systems and appliance installations shall be $ for the first $1,000.00, or fraction thereof, of
valuation of the installation pliis $ for each additional $1 ,000.00 or fraction thereof.
BlOl.2.2 Fee for inspecting repairs, alterations and additions to an existing system shall be $ plus $ for each $ 1 ,000.00 or
fraction thereof .
BlOl.2.3 Fee for inspecting boilers (based upon Btu input):
33,000 Btu (1 BHp) to 165,000 (5 BHp) $
165,001 Btu (5 BHp) to 330,000 (10 BHp) $
330,001 Btu (10 BHp) to 1,165,000 (52 BHp) $
1,165,001 Btu (52 BHp) to 3,300,000 (98 BHp) $
over 3,300,000 Btu (98 BHp) $
For SI: 1 British thermal unit = 0.293 1 W, 1 BHp = 33,475 Btu/hr.
B102
FEE FOR REINSPECTION
If it becomes necessary to make a reinspection of a heating, ventilation, air-conditioning or refrigeration system, or boiler installa-
tion, the installer of such equipment shall pay a reinspection fee of $ .
B103
TEMPORARY OPERATION INSPECTION FEE
When preliminary inspection is requested for purposes of permitting temporary operation of a heating, ventilating, refrigeration, or
air-conditioning system, or portion thereof, a fee of $_ shall be paid by the contractor requesting such preliminary inspection. If
the system is not approved for temporary operation on the first preliminary inspection, the usual reinspection fee shall be charged
for each subsequent preliminary irispection for such purpose.
8104
SELF-CONTAINED UNITS LESS THAN 2 TONS
In all buildings, except one- and two-family dwellings, where self-contained air-conditioning units of less than 2 tons are to be
installed, the fee charged shall be that for the total costof all units combined (see B 101. 2.1 for rate).
2007 OREGON MECHANICAL SPECIALTY CODE 1 1 5
116 2007 OREGON WiECHANICAL SPECIALTY CODE
APPENDIX C
FUEL GAS
•>
SECTION C1 01
GENERAL
ClOl.l Scope. This appendix shall apply to the installation of
I fuel gas piping systems, fuel gas utilization equipment, gas-
' eous hydrogen systems and related accessories in accordance
I I with Sections ClOl.1.1 through ClOl.1.4.
Exception: Detached one- and two-family dwellings and
multiple single-family dwellings (townhouses) not more
than three stories high with separate means of egress and
their accessory structures shall comply with the Oregon
Residential Specialty Code.
■^ ClOl.1.1 Gaseous hydrogen systems. Gaseous hydrogen
systems shall be regulated by Section C701.
ClOl.1.2 Piping systems. These regulations cover piping
systems for natural gas with an operating pressure of 1 25
pounds per square inch gauge (psig) (862 kPa gauge) or
less, and for LP-gas with an operating pressure of 20 psig
(140 kPa gauge) or less, except as provided in Section
C402.6.1. Coverage shall extend from the point of delivery
to the outlet of the equipment shutoff valves. Piping systems
requirements shall include design, materials, components,
fabrication, assembly, installation, testing and inspection.
ClOl.1.3 Gas utilization equipment. Requirements for
gas utilization equipment and related accessories shall
include installation, combustion and ventilation air and
venting and connections to piping systems.
ClOl.1.4 Systems and equipment outside the scope. This
code shall not apply to the following:
II
>
'>
1 . Portable fuel-gas utilization equipment of all types
that is not connected to a fixed fuel piping system.
2. Raw material (feedstock) applications except for
piping to special atmosphere generators.
3. Oxygen-fuel gas cutting and welding systems.
4. Industrial gas applications using gases such as acet-
ylene and acetylenic compounds, hydrogen, ammo-
nia, carbon monoxide, oxygen and nitrogen.
5 . Petroleum refineries, pipeline compressor or pump-
ing stations, loading terminals, compounding
plants, refinery tank farms and natural gas process-
ing plants.
6. Integrated chemical plants or portions of such plants
where flammable or combustible liquids or gases
are produced by, or used in, chemical reactions.
7. LP-gas installations at utility gas plants.
8. Liquefied natural gas (LNG) installations.
9. Proprietary items of equipment, apparatus or instru-
ments such as gas-generating sets, compressors and
calorimeters.
10. LP-gas equipment for vaporization, gas mixing and
gas manufacturing.
11. Temporary fuel-gas piping or hoses for buildings
under construction or renovation that is not to
become part of the permanent piping system.
12. Installation of LP-gas systems for railroad switch
heating.
13. Installation of hydrogen gas, LP-gas and com-
pressed natural gas (CNG) systems on vehicles.
14. Except as provided in Section C40 1.1.1, gas piping,
meters, gas pressure regulators and other appurte-
nances used by the serving gas supplier in the distri-
bution of gas, other than undiluted LP-gas.
15. Building design and construction, except as speci-
fied herein.
16. Piping systems for mixtures of gas and air within the
flammable range with an operating pressure greater
than 10 psig (69 kPa gauge).
17. Portable fuel cell appliances that are neither con-
nected to a fixed piping system nor interconnected
to a power grid.
C101.2 Intent. The purpose of this code or appendix is to pro-
vide minimum standards to safeguard life or limb, health, prop-
erty and public welfare by regulating and controlling the
design, construction, installation, quality of materials and loca-
tion of fuel gas systems.
C101.3 Severabihty. If a section, subsection, sentence, clause
or phrase of this code or appendix is, for any reason, held to be
unconstitutional, such decision shall not affect the validity of
the remaining portions of this code.
SECTION C102
INSPECTIONS AND TESTING
C102.1 Required inspections and testing. The code official,
upon notification from the permit holder or the permit holder's
agent, shall make the following inspections and other such
inspections as necessary, and shall either release that portion of
the construction or notify the permit holder or the permit
holder's agent of violations that are required to be corrected.
The holder of the permit shall be responsible for scheduling
such inspections.
1 . Underground inspection shall be made after trenches or
ditches are excavated and bedded, piping is installed and
before backfill is put in place. When excavated soil con-
tains rocks, broken concrete, frozen chunks and other
rubble that would damage or break the piping or cause
corrosive action, clean backfill shall be on the job site.
2. Rough-in inspection shall be made after the roof, fram-
ing, fireblocking and bracing are in place and compo-
<
II
<
II
<
2007 OREGON MECHANICAL SPECIALTY CODE
117.1
APPENDIX C
>
>
II
nents to be concealed are complete, and prior to the
installation of wall or ceiling membranes.
3. Final inspection shall be made upon completion of the
installation.
The requirements of this section shall not be considered to
prohibit the operation of any heating equipment installed to
replace existing heating equipment serving an occupied por-
tion of a structure in the event a request for inspection of such
heating equipment has been filed with the department not more
than 48 hours after replacement work is completed, and before
any portion of such equipment is concealed by any permanent
portion of the structure.
C102.2 Testing. Installations shall be tested as required in this
code and in accordance with Sections C102.1 through C102.3.
Tests shall be made by the permit holder and observed by the
code official.
>
LI New, altered, extended or repaired installa-
tions. New installations and parts of existing installations,
which have been altered, extended, renovated or repaired,
shall be tested as prescribed herein to disclose leaks and
defects.
C 1(02.2.2 Apparatus, instruments, material and labor
for tests. Apparatus, instruments, material and labor
required for testing an installation or part thereof shall be
furnished by the permit holder.
C102.2.3 Reinspection and testing. Where any work or
installation does not pass an initial test or inspection, the
necessary corrections shall be made so as to achieve compli-
ance with this code. The work or installation shall then be
resubmitted to the code official for inspection and testing.
C102.3 Approval. After the prescribed tests and inspections
indicate that the work complies in all respects with this appen-
dix, a notice of approval shall be issued by the code official.
C102.4 Temporary connection. The code official shall have
the authority to allow the temporary connection of an installa-
tion to the sources of energy for the purpose of testing the
installation or for use under a temporary certificate of occu-
pancy.
SECTION C201
GENERAL
C201.1 Scope. Unless otherwise expressly stated, the follow-
ing words and terms shall, for the purposes of this code and
standard, have the meanings indicated in this chapter.
C201.2 Interchangeability. Words used in the present tense
include the future; words in the masculine gender include the
feminine and neuter; the singular number includes the plural
and the plural, the singular.
C201.3 Terms defined in other codes. Where terms are not
defined in this code and are defined in the Electrical Code,
Building Code, Fire Code, Mechanical Code or Plumbing
Code, such terms shall have meanings ascribed to them as in
those codes.
C201,4 Terms not defined. Except as defined in this chapter or
elsewhere in this code, the interpretation of words used in this
code shall be in accordance with the meanings defined in the
Webster's Third New International Dictionary of the English
Language, Unabridged, copyright 1986.
SECTION C202
GENERAL DEFINITIONS
ACCESS (TO). That which enables a device, appliance or
equipment to be reached by ready access or by a means that first
requires the removal or movement of a panel, door or similar
obstrucdon (see also "Ready access")-
AIR CONDITIONER, GAS-FIRED. A gas-burning, auto-
matically operated appliance for supplying cooled and/or
dehumidified air or chilled liquid.
AIR CONDITIONING. The treatment of air so as to control
simultaneously the temperature, humidity, cleanness and dis-
tribution of the air to meet the requirements of a conditioned
space.
AIR-HANDLING UNIT. A blower or fan used for the pur-
pose of distributing supply air to a room, space or area.
AIR, MAKEUP. Air that is provided to replace air being
exhausted.
ANODELESS RISER. A transition assembly in which plastic
piping is installed and terminated above ground outside of a
building..
APPLIANCE (EQUIPMENT). Any apparatus or equipment
that utilizes gas as a fuel or raw material to produce light, heat,
power, refrigeration or air conditioning.
APPLIANCE, FAN- ASSISTED COMBUSTION. An apph-
ance equipped with an integral mechanical means to eithei"
draw or force products of combustion through the combustion
chamber or heat exchanger.
APPLIANCE, AUTOMATICALLY
Appliances equipped with an automatic burner ignition and
safety shutoff device and other automatic devices which
accomplish complete turn-on and shutoff of the gas to the main
burner or burners, and graduate the gas supply to the burner or
burners, but do not affect complete shutoff of the gas.
APPLIANCE TYPE.
Low-heat appliance (residential appliance). Any appli-
ance in which the products of combustion at the point of
entrance to the flue under normal operating conditions have
a temperature of 1,000°F (538°C) or less.
Medium-heat appliance. Any appliance in which the prod-
ucts of combustion at the point of entrance to the flue under
normal operating conditions have a temperature of more
than 1,000°F (538°C), but not greater than 2,000°F
(1093°C).
APPLIANCE, UNVENTED. An appliance designed or
installed in such a manner that the products of combustion are
not conveyed by a vent or chimney directly to the outside atmo-
sphere.
APPLIANCE, VENTED. An appliance designed and
installed in such a manner that all of the products of combus-
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2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
>
tion are conveyed directly from the appliance to the outside
atmosphere through an approved chimney or vent system.
ATMOSPHERIC PRESSURE. The pressure of the weight of
air and water vapor on the surface of the earth, approximately
14.7 pounds per square inch (psi) (101 kPa absolute) at sea
level.
AUTOMATIC IGNITION. Ignition of gas at the bumer(s)
when the gas controlling device is turned on, including
reignition if the flames on the burner(s) have been extinguished
by means other than by the closing of the gas controlling
device.
BAFFLE. An object placed in an appliance to change the
direction of or retard the flow of air, air-gas mixtures or flue
gases.
BAROMETRIC DRAFT REGULATOR. A balanced
damper device attached to a chimney, vent connector, breech-
ing or flue gas manifold to protect combustion equipment by
controlling chimney draft. A double-acting barometric draft
regulator is one whose balancing damper is free to move in
either direction to protect combustion equipment from both
excessive draft and backdraft.
BRAZING. A metal-joining process wherein coalescence is
produced by the use of a nonferrous filler metal having a melt-
ing point above 1,000°F (538°C), but lower than that of the
base metal being joined. The filler material is distributed
between the closely fitted surfaces of the joint by capillary
action.
BROILER. A general term including salamanders, barbecues
and other appliances cooking primarily by radiated heat,
excepting toasters.
BTU. Abbreviation for British thermal unit, which is the quan-
tity of heat required to raise the temperature of 1 pound (454 g)
of water 1°F (0.56°C) (1 Btu = 1055 J).
I. A device for the final conveyance of the gas, or a
mixture of gas and air, to the combustion zone.
Imduced-draft. A burner that depends on draft induced by a
fan that is an integral part of the appliance and is located
downstream from the burner.
Power. A burner in which gas, air or both are supplied at
pressures exceeding, for gas, the line pressure, and for air,
atmospheric pressure, with this added pressure being
applied at the burner.
CHIMNEY. A primarily vertical structure containing one or
more flues, for the purpose of carrying gaseous products of
combustion and air from an appliance to the outside atmo-
sphere.
Factory-built chimney. A listed and labeled chimney com-
posed of factory-made components, assembled in the field
in accordance with manufacturer's instructions and the con-
ditions of the listing.
Masonry chimney. A field-constructed chimney composed
of solid masonry units, bricks, stones or concrete.
Metal chimney. A field-constructed chimney of metal.
CLEARANCE. The minimum distance through air measured
between the heat-producing surface of the mechanical appli-
ance, device or equipment and the surface of the combustible
material or assembly.
COMBUSTION. In the context of this code, refers to the rapid
oxidation of fuel accompanied by the production of heat or heat
and light.
COMBUSTION AIR. Air necessary for complete combus-
tion of a fuel, including theoretical air and excess air.
COMBUSTION CHAMBER. The portion of an appliance
within which combustion occurs.
COMBUSTION PRODUCTS. Constituents resulting from
the combustion of a fuel with the oxygen of the air, including
inert gases, but excluding excess air.
CONCEALED LOCATION. A location that cannot be
accessed without damaging permanent parts of the building
structure or finish surface. Spaces above, below or behind
readily removable panels or doors shall not be considered as
concealed.
CONCEALED PIPING. Piping that is located in a concealed
location (see "Concealed location").
CONDENSATE. The liquid that condenses from a gas
(including flue gas) caused by a reduction in temperature or
increase in pressure.
CONNECTOR, APPLIANCE (Fuel). Rigid metalhc pipe
and fittings, semirigid metallic tubing and fittings or a listed
and labeled device that connects an appliance to the gas piping
system.
CONNECTOR, CHIMNEY OR VENT. The pipe that con-
nects an appliance to a chimney or vent.
CONTROL. A manual or automatic device designed to regu-
late the gas, air, water or electrical supply to, or operation of, a
mechanical system.
CONVERSION BURNER. A unit consisting of a burner and
its controls for installation in an appliance originally utilizing
another fuel.
COUNTER APPLIANCES. Appliances such as coffee brew-
ers and coffee urns and any appurtenant water-heating equip-
ment, food and dish warmers, hot plates, griddles, waffle
bakers and other appliances designed for installation on or in a
counter.
CUBIC FOOT. The amount of gas that occupies 1 cubic foot
(0.02832 m^) when at a temperature of 60°F (16°C), saturated
with water vapor and under a pressure equivalent to that of 30
inches of mercury (101 kPa).
DAMPER. A manually or automatically controlled device to
regulate draft or the rate of flow of air or combustion gases.
DECORATIVE APPLIANCE, VENTED. A vented appli-
ance wherein the primary function lies in the aesthetic effect of
the flames.
DECORATIVE APPLIANCES FOR INSTALLATION IN
VENTED FIREPLACES. A vented appliance designed for
installation within the fire chamber of a vented fireplace,
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2007 OREGON MECHANICAL SPECIALTY CODE
117.3
APPENDIX C
wherein the primary function lies in the aesthetic effect of the
flames.
DEMAND. The maximum amount of gas input required per
unit of time, usually expressed in cubic feet per hour, or Btu/h
(1 Btu/h = 0.2931 W).
DESIGN FLOOD ELEVATION. The elevation of the
"design flood," including wave height, relative to the datum
specified on the community's legally designated flood hazard
map.
DILUTION AIR. Air that is introduced into a draft hood and
is mixed with the flue gases.
DIRECT- VENT APPLIANCES, Appliances that are con-
structed and installed so that all air for combustion is derived
directly from the outside atmosphere and all flue gases are dis-
charged directly to the outside atmosphere.
DRAFT. The pressure difference existing between the equip-
ment or any component part and the atmosphere, that causes a
continuous flow of air and products of combustion through the
gas passages of the appliance to the atmosphere.
Mechanical or Induced draft. The pressure difference cre-
ated by the action of a fan, blower or ejector, that is located
between the appliance and the chimney or vent termination.
Natural draft. The pressure difference created by a vent or
chimney because of its height, and the temperature differ-
ence between the flue gases and the atmosphere.
DRAFT HOOD. A nonadjustable device built into an appli-
ance, or made as part of the vent connector from an appliance,
that is designed to (1) provide for ready escape of the flue gases
from the appliance in the event of no draft, backdraft or stop-
page beyond the draft hood, (2) prevent a backdraft from enter-
ing the appliance, and (3) neutralize the effect of stack action of
the chimney or gas vent upon operation of the appliance.
DRAFT REGULATOR, A device that functions to maintain a
desired draft in the appliance by automatically reducing the
draft to the desired value.
DRIP. The container placed at a low point in a system of piping
to collect condensate and from which the condensate is remov-
able.
DRY GAS, A gas having a moisture and hydrocarbon dew
point below any normal temperature to which the gas piping is
exposed.
DUCT FURNACE. A warm-air furnace normally installed in
an air distribution duct to supply warm air for heating. This def-
inition shall apply only to a warm-air heating appliance that
depends for air circulation on a blower not furnished as part of
the furnace.
DUCT SYSTEM, A continuous passageway for the transmis-
sion of air that, in addition to ducts, includes duct fittings,
dampers, plenums, fans and accessory air-handling equipment.
EQUIPMENT. See "Apphance."
FIRING VALVE. A valve of the plug and barrel type designed
for use with gas, and equipped with a lever handle for manual
operation and a dial to indicate the percentage of opening.
FLAME SAFEGUARD. A device that will automatically shut
off the fuel supply to a main burner or group of burners when
the means of ignition of such burners becomes inoperative, and
when flame failure occurs on the burner or group of burners.
FLOOD HAZARD AREA. The greater of the following two
areas:
1. The area within a floodplain subject to a 1 percent or
greater chance of flooding in any given year.
2. This area designated as a flood hazard area on a commu-
nity's flood hazard map, or otherwise legally designated.
FLOOR FURNACE. A completely self-contained furnace
suspended from the floor of the space being heated, taking air
for combustion from outside such space and with means for
observing flames and lighting the appliance from such space.
Gravity type. A floor furnace depending primarily upon
circulation of air by gravity. This classification shall also
include floor furnaces equipped with booster-type fans
which do not materially restrict free circulation of air by
gravity flow when such fans are not in operation.
Fan type. A floor furnace equipped with a fan which pro-
vides the primary means for circulating air.
FLUE, APPLIANCE. The passage(s) within an appliance
through which combustion products pass from the combustion
chamber of the appliance to the draft hood inlet opening on an
appliance equipped with a draft hood or to the outlet of the
appliance on an appliance not equipped with a draft hood.
FLUE COLLAR. That portion of an appliance designed for
the attachment of a draft hood, vent connector or venting sys-
tem.
FLUE GASES. Products of combustion plus excess air in
appliance flues or heat exchangers.
FLUE LINER (LINING). A system or material used to form
the inside surface of a flue in a chimney or vent, for the purpose
of protecting the surrounding structure from the effects of com-
bustion products and for conveying combustion products with-
out leakage to the atmosphere.
FUEL GAS. A natural gas, manufactured gas, liquefied petro-
leum gas or mixtures of these gases.
FUEL GAS UTILIZATION EQUIPMENT, See "Appli-
ance."
FURNACE. A completely self-contained heating unit that is
designed to supply heated air to spaces remote from or adjacent
to the appliance location.
FURNACE, CENTRAL. A self-contained appliance for heat-
ing air by transfer of heat of combustion through metal to the
air, and designed to supply heated air through ducts to spaces
remote from or adjacent to the appliance location.
Downflow furnace, A furnace designed with airflow dis-
charge vertically downward at or near the bottom of the fur-
nace.
Forced air furnace with cooling unit, A single-package
unit, consisting of a gas-fired forced-air furnace of one of
the types listed below combined with an electrically or fuel
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2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
gas-powered summer air-conditioning system, contained in
a common casing.
Forced-air type. A central furnace equipped with a fan or
blower which provides the primary means for circulation of
air.
Gravity furnace with booster fan. A furnace equipped
with a booster fan that does not materially restrict free circu-
lation of air by gravity flow when the fan is not in operation.
Gravity type. A central furnace depending primarily on cir-
culation of air by gravity.
Horizontal forced-air type. A furnace with airflow
through the appliance essentially in a horizontal path.
Multiple-position furnace. A furnace designed so that it
can be installed with the airflow discharge in the upflow,
horizontal or downflow direction.
Upflow furnace. A furnace designed with airflow dis-
charge vertically upward at or near the top of the furnace.
This classification includes "highboy" furnaces with the
blower mounted below the heating element and "lowboy"
furnaces with the blower mounted beside the heating ele-
ment.
FURNACE, ENCLOSED. A specific heating, or heating and
ventilating, furnace incorporating an integral total enclosure
and using only outside air for combustion.
FURNACE PLENUM. An air compartment or chamber to
which one or more ducts are connected and which forms part of
an air distribution system.
GAS CONVENIENCE OUTLET. A permanently mounted,
manually operated device that provides the means for connect-
ing an appliance to, and disconnecting an appliance from, the
supply piping. The device includes an integral, manually oper-
ated valve with a nondisplaceable valve member and is
designed so that disconnection of an appliance only occurs
when the manually operated valve is in the closed position.
GASEOUS HYDROGEN SYSTEM. See Section C702.1.
GAS PIPING. An installation of pipe, valves or fittings
installed on a premises or in a building and utilized to convey
fuel gas.
GAS UTILIZATION EQUIPMENT. An appliance that uti-
lizes gas as a fuel or raw material or both.
HAZARDOUS LOCATION. Any location considered to be a
fire hazard for flammable vapors, dust, combustible fibers or
other highly combustible substances. The location is not neces-
sarily categorized in the building code as a high-hazard group
classification.
HOUSE PIPING. See "Piping system."
HYDROGEN CUT-OFF ROOM. See Section C702.1.
HYDROGEN GENERATING APPLIANCE. See Section
C702.1.
IGNITION PILOT. A pilot that operates during the lighting
cycle and discontinues during main burner operation.
IGNITION SOURCE. A flame, spark or hot surface capable
of igniting flammable vapors or fumes. Such sources include
appliance burners, burner ignitors, and electrical switching
devices.
INCINERATOR. An appliance used to reduce combustible
refuse material to ashes and which is manufactured, sold and
installed as a complete unit.
INDUSTRIAL AIR HEATERS, DIRECT-FIRED
NONRECIRCULATING. A heater in which all the products
of combustion generated by the burners are released into the air
stream being heated. The purpose of the heater is to offset
building heat loss by heating only outdoor air.
INDUSTRIAL AIR HEATERS, DIRECT-FIRED RECIR-
CULATING. A heater in which all the products of combustion
generated by the burners are released into the air stream being
heated. The purpose of the heater is to offset building heat loss
by heating outdoor air, and, if applicable, indoor air.
INFRARED RADIANT HEATER. A heater that directs a
substantial amount of its energy output in the form of infrared
radiant energy into the area to be heated. Such heaters are of
either the vented or unvented type.
JOINT, FLANGED. A joint made by bolting together a pair of
flanged ends.
JOINT, FLARED. A metal-to-metal compression joint in
which a conical spread is made on the end of a tube that is com-
pressed by a flare nut against a mating flare.
JOINT, MECHANICAL. A general form of gas-tight joints
obtained by the joining of metal parts through a positive-hold-
ing mechanical construction, such as flanged joint, threaded
joint, flared joint or compression joint.
JOINT, PLASTIC ADHESIVE. A joint made in thermoset
plastic piping by the use of an adhesive substance which forms
a continuous bond between the mating surfaces without dis-
solving either one of them.
JOINT, PLASTIC HEAT FUSION. A joint made in thermo-
plastic piping by heating the parts sufficiently to permit fusion
of the materials when the parts are pressed together.
JOINT, WELDED. A gas-tight joint obtained by the joining
of metal parts in molten state.
LABELED. Devices, equipment, appliances or materials to
which have been affixed a label, seal, symbol or other identify-
ing mark of a nationally recognized testing laboratory, inspec-
tion agency or other organization concerned with product
evaluation that maintains periodic inspection of the production
of the above-labeled items and by whose label the manufac-
turer attests to compliance with applicable nationally recog-
nized standards.
LIMIT CONTROL. A device responsive to changes in pres-
sure, temperature or level for turning on, shutting off or throt-
tling the gas supply to an appliance.
LIQUEFIED PETROLEUM GAS or LPG (LP-GAS). Liq-
uefied petroleum gas composed predominately of propane,
propylene, butanes or butylenes, or mixtures thereof that is gas-
eous under normal atmospheric conditions, but is capable of
being liquefied under moderate pressure at normal tempera-
tures.
2007 OREGON MECHANICAL SPECIALTY CODE
117.5
APPENDIX C
>
>
LISTED. Equipment, appliances or materials included in a list
published by a nationally recognized testing laboratory, inspec-
tion agency or other organization concerned with product evalu-
ation that maintains periodic inspection of production of listed
equipment, appliances or materials, and whose hsting states
either that the equipment, appliance or material meets nationally
recognized standards or has been tested and found suitable for
use in a specified manner. The means for identifying Usted
equipment, appUances or materials may vary for each testing
laboratory, inspection agency or other organization concerned
with product evaluation, some of which do not recognize equip-
ment, appliances or materials as listed unless they are also
labeled. The authority having jurisdiction shall utilize the system
employed by the listing organization to identify a listed product.
LOG LIGHTER, A manually operated solid fuel ignition
appliance for installation in a vented solid fuel -burning fire-
place.
LUBRICATED PLUG-TYPE VALVE, A valve of the plug
and barrel type provided with means for maintaining a lubri-
cant between the bearing surfaces.
BURNER. A device or group of devices essentially
forming an integral unit for the final conveyance of gas or a
mixture of gas and air to the combustion zone, and on which
combustion takes place to accomplish the function for which
the appliance is designed.
METER. The instrument installed to measure the volume of
gas delivered through it.
MODULATING. Modulating or throttling is the action of a
control from its maximum to minimum position in either pre-
determined steps or increments of movement as caused by its
actuating medium.
OFFSET (VENT). A combination of approved bends that
makes two changes in direction bringing one section of the vent
out of line but into a line parallel with the other section.
ORIFICE. The opening in a cap, spud or other device whereby
the flow of gas is limited and through which the gas is dis-
charged to the burner.
OUTLET. A threaded connection or bolted flange in a pipe
system to which a gas-burning appliance is attached.
OXYGEN DEPLETION SAFETY SHUTOFF SYSTEM
(ODS). A system designed to act to shut off the gas supply to
the main and pilot burners if the oxygen in the surrounding
atmosphere is reduced below a predetermined level.
r. A small flame that is utilized to ignite the gas at the
main burner or burners.
T. Where used in this code, "piping" refers to either
pipe or tubing, or both.
Pipe. A rigid conduit of iron, steel, copper, brass or plastic.
Ibbing. Semirigid conduit of copper, aluminum, plastic or
steel.
PIPING SYSTEM. All fuel piping, valves and fittings from
the outlet of the point of delivery to the outlets of the equipment
shutoff valves.
1 . Spring type, limited adjustment. A regulator in which
the regulating force acting upon the diaphragm is
derived principally from a spring, the loading of
which is adjustable over a range of not more than 15
percent of the outlet pressure at the midpoint of the
adjustment range.
2. Spring type, standard adjustment. A regulator in which
the regulating force acting upon the diaphragm is
derived principally from a spring, the loading of which
is adjustable. The adjustment means shall be concealed.
Multistage. A regulator for use with a single gas whose
adjustment means is capable of being positioned manually
or automatically to two or more predetermined outlet pres-
sure settings. Each of these settings shall be adjustable or
PLASTIC, THERMOPLASTIC. A plastic that is capable of
being re]3eatedly softened by increase of temperature and hard-
ened by decrease of temperature.
POINT OF DELIVERY. For natural gas systems, the point of
delivery is the outlet of the service meter assembly or the outlet
of the service regulator or service shutoff valve where a meter
is not provided. Where a valve is provided at the outlet of the
service meter assembly, such valve shall be considered to be
downstream of the point of delivery. For undiluted liquefied
petroleum gas systems, the point of delivery shall be consid-
ered to be the outlet of the first- stage pressure regulator that
provides utilization pressure, exclusive of line gas regulators,
in these systems.
PORTABLE FUEL CELL APPLIANCE. A fuel cell gener-
ator of electricity, which is not fixed in place. A portable fuel
cell appliance utilizes a cord and plug connection to a grid-iso-
lated load and has an integral fuel supply.
PRESSURE DROP. The loss in pressure due to friction or
obstruction ijn pipes, valves, fittings, regulators and burners.
PRESSURE TEST. An operation performed to verify the
gas-tight integrity of gas piping following its installation or
modification.
PURGE. To free a gas conduit of air or gas, or a mixture of gas
and air.
QUICK-DISCONNECT DEVICE. A hand-operated device
that provides a means for connecting and disconnecting an
appliance or an appliance connector to a gas supply and that is
equipped with an automatic means to shut off the gas supply
when the device is disconnected.
READY ACCESS (TO). That which enables a device, appli-
ance or equipment to be directly reached, without requiring the
removal or movement of any panel, door or similar obstruction
(see "Access"). <;
REGULATOR. A device for controlling and maintaining a
uniform supply pressure, either pounds-to-inches water col-
unm (MP regulator) or inches-to-inches water column (appli-
ance regulator).
REGULATOR, GAS APPLIANCE. A pressure regulator for
controlling pressure to the manifold of equipment. Types of
appliance regulators are as follows:
117.6
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
>
>
nonadjustable. The regulator may modulate outlet pressures
automatically between its maximum and minimum prede-
termined outlet pressure settings.
Nonadjustable,
1. Spring type, nonadjustable. A regulator in which the
regulating force acting upon the diaphragm is derived
principally from a spring, the loading of which is not
field adjustable.
2. Weight type. A regulator in which the regulating
force acting upon the diaphragm is derived from a
weight or combination of weights.
REGULATOR, LINE GAS PRESSURE. A device placed in
a gas line between the service pressure regulator and the equip-
ment for controlling, maintaining or reducing the pressure in
that portion of the piping system downstream of the device.
REGULATOR, MEDIUM-PRESSURE (MP Regulator).
A line pressure regulator that reduces gas pressure from the
range of greater than 0.5 psig (3.4 kPa) and less than or equal to
5 psig (34.5 kPa) to a lower pressure.
REGULATOR, PRESSURE. A device placed in a gas line for
reducing, controlling and maintaining the pressure in that por-
tion of the piping system downstream of the device.
REGULATOR, SERVICE PRESSURE. A device installed
by the serving gas supplier to reduce and limit the service line
pressure to delivery pressure.
RELIEF OPENING. The opening provided in a draft hood to
permit the ready escape to the atmosphere of the flue products
from the draft hood in the event of no diraft, back draft, or stop-
page beyond the draft hood, and to permit air into the draft hood
in the event of a strong chimney updraft.
RISER, GAS. A vertical pipe supplying fuel gas.
ROOM HEATER, UNVENTED. See "Unvented room heater."
ROOM HEATER, VENTED. A free-standing heating unit
used for direct heating of the space in and adjacent to that in
which the unit is located (see also "Vented room heater").
ROOM LARGE IN COMPARISON WITH SIZE OF
EQUIPMENT. Rooms having a volume equal to at least 12
times the total volume of a furnace or air-conditioning appli-
ance and at least 1 6 times the total volume of a boiler. Total vol-
ume of the appliance is determined from exterior dimensions
and is to include fan compartments and burner vestibules, when
used. When the actual ceiling height of a room is greater than 8
feet (2438 mm), the volume of the room is figured on the basis
of a ceihng height of 8 feet (2438 mm).
SAFETY SHUTOFF DEVICE. See "Flame safeguard."
SHAFT. An enclosed space extending through one or more
stories of a building, connecting vertical openings in succes-
sive floors, or floors and the roof.
SPECIFIC GRAVITY. As applied to gas, specific gravity is
the ratio of the weight of a given volume to that of the same vol-
ume of air, both measured under the same condition.
STATIONARY FUEL CELL POWER PLANT. A self con-
tained package or factory-matched packages which constitute
an automatically operated assembly of integrated systems for
generating electrical energy and recoverable thermal energy
that is permanently connected and fixed in place.
THERMOSTAT.
Electric switch type. A device that senses changes in tem-
perature and controls electrically, by means of separate
components, the flow of gas to the burner(s) to maintain
selected temperatures.
Integral gas valve type. An automatic device, actuated by
temperature changes, designed to control the gas supply to
the burner(s) in order to maintain temperatures between pre-
determined limits, and in which the thermal actuating ele-
ment is an integral part of the device.
1. Graduating thermostat. A thermostat in which the
motion of the valve is approximately in direct propor-
tion to the effective motion of the thermal element
induced by temperature change.
2. Snap-acting thermostat. A thermostat in which the
thermostatic valve travels instantly from the closed to
the open position, and vice versa.
TRANSITION FITTINGS, PLASTIC TO STEEL. An
adapter for joining plastic pipe to steel pipe. The purpose of this
fitting is to provide a permanent, pressure-tight connection
between two materials which cannot be joined directly one to
another.
UNIT HEATER.
High-static pressure type. A self-contained, automatically
controlled, vented appliance having integral means for cir-
culation of air against 0.2 inch (15 mm HjO) or greater static
pressure. Such appliance is equipped with provisions for
attaching an outlet air duct and, where the appliance is for
indoor installation remote from the space to be heated, is
also equipped with provisions for attaching an inlet air duct.
Low-static pressure type. A self-contained, automatically
controlled, vented appliance, intended for installation in the
space to be heated without the use of ducts, having integral
means for circulation of air. Such units are allowed to be
equipped with louvers or face extensions made in accor-
dance with the manufacturer's specifications. ^
UNVENTED ROOM HEATER. An unvented heating appli-
ance designed for stationary installation and utilized to provide
comfort heating. Such appliances provide radiant heat or con-
vection heat by gravity or fan circulation directly from the
heater and do not utilize ducts.
VALVE. A device used in piping to control the gas supply to
any section of a system of piping or to an appliance.
Automatic. An automatic or semiautomatic device consist-
ing essentially of a valve and operator that control the gas
supply to the bumer(s) during operation of an appliance.
The operator shall be actuated by apphcation of gas pressure
on a flexible diaphragm, by electrical means, by mechanical
means, or by other approved means.
Automatic gas shutoff. A valve used in conjunction with an
automatic gas shutoff device to shut off the gas supply to a
water-heating system. It shall be constructed integrally with
the gas shutoff device or shall be a separate assembly.
2007 OREGON MECHANICAL SPECIALTY CODE
117.7
APPENDIX C
Equipment shutoff. A valve located in the piping system,
used to isolate individual equipment for purposes such as
service or replacement.
Imdividual main burner. A valve that controls the gas sup-
ply to an individual main burner.
Main burner control. A valve that controls the gas supply
to the main burner manifold.
Manual main gas-controL A manually operated valve in
the gas line for the purpose of completely turning on or shut-
ting off the gas supply to the appliance, except to pilot or
pilots that are provided with independent shutoff.
An automatic shutoff valve installed in the
gas supply piping and set to shut off when unsafe conditions
occur. The device remains closed until manually reopened.
Service shutoff. A valve, installed by the serving gas sup-
plier between the service meter or source of supply and the
customer piping system, to shut off the entire piping system.
A pipe or other conduit composed of factory-made
components, containing a passageway for conveying combus-
tion products and air to the atmosphere, listed and labeled for
use with a specific type or class of appliance.
Special gas vent. A vent listed and labeled for use with
listed Category II, III and IV appliances.
Type B vent. A vent listed and labeled for use with appli-
ances with draft hoods and other Category I appliances that
are listed for use with Type B vents.
Type BW vent. A vent listed and labeled for use with wall
furnaces.
Type L vent. A vent listed and labeled for use with appli-
ances that are listed for use with Type L or Type B vents.
VENT CONNECTOR. See "Connector."
VENT GASES. Products of combustion from appliances plus
excess air plus dilution air in the vent connector, gas vent or
chimney above the draft hood or draft regulator.
Breather. Piping run from a pressure-regulating device to
the outdoors, designed to provide a reference to atmo-
spheric pressure. If the device incorporates an integral pres-
sure relief mechanism, a breather vent can also serve as a
relief vent.
Relief. Piping run from a pressure-regulating or pres-
sure-limiting device to the outdoors, designed to provide for
the safe venting of gas in the event of excessive pressure in
the gas piping system.
VENTED APPLIANCE CATEGORIES. Appliances that
are categorized for the purpose of vent selection are classified
into the following four categories:
Category I. An appliance that operates with a nonpositive
vent static pressure and with a vent gas temperature that
avoids excessive condensate production in the vent.
Category II, An appliance that operates with a nonpositive
vent static pressure and with a vent gas temperature that is
capable of causing excessive condensate production in the
vent.
Category III. An appliance that operates with a positive
vent static pressure and with a vent gas temperature that
avoids excessive condensate production in the vent.
Category IV. An appliance that operates with a positive vent
static pressure and with a vent gas temperature that is capable
of causing excessive condensate production in the vent.
VENTED ROOM HEATER. A vented self-contained,
free-standing, nonrecessed appliance for furnishing warm air
to the space in which it is installed, directly from the heater
without duct connections.
VENTED WALL FURNACE. A self-contained vented appli-
ance complete with grilles or equivalent, designed for incorpo-
ration in or permanent attachment to the structure of a building,
mobile home or travel trailer, and furnishing heated air circu-
lated by gravity or by a fan directly into the space to be heated
through openings in the casing. This definition shall exclude
floor furnaces, unit heaters and central furnaces as herein
defined.
VENTING SYSTEM. A continuous open passageway from
the flue collar or draft hood of an appliance to the outside atmo-
sphere for the purpose of removing flue or vent gases. A vent-
ing system is usually composed of a vent or a chimney and vent
connector, if used, assembled to form the open passageway.
Mechanical draft venting system, A venting system
designed to remove flue or vent gases by mechanical means,
that consists of an induced draft portion under nonpositive
static pressure or a forced draft portion under positive static
pressure.
Forced-draft venting system, A portion of a venting system
using a fan or other mechanical means to cause the removal of
flue or vent gases under positive static vent pressure.
Induced draft venting system. A portion of a venting sys-
tem using a fan or other mechanical means to cause the
removal of flue or vent gases under nonpositive static vent
pressure.
Natural draft venting system. A venting system designed
to remove flue or vent gases under nonpositive static vent
pressure entirely by natural draft.
WALL HEATER, UNVENTED-TYPE. A room heater of the
type designed for insertion in or attachment to a wall or parti-
tion. Such heater does not incorporate concealed venting
arrangements in its construction and discharges all products of
combustion through the front into the room being heated.
SECTION C301
GENERAL
C301,l Scope. This chapter shall govern the approval and
installation of all equipment and appliances that comprise parts
of the installations regulated by this code in accordance with
Section CI 01.1.
Equipment and appliances shall not be installed, altered or
used in violation of this code. The fuel input rate to equipment
117.8
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
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shall not be increased in excess of the approved Btu/h (W) rat-
ing at the altitude where it is being used.
C301.1.1 Other fuels. The requirements for combustion
and dilution air for gas-fired appliances shall be governed
by Section C304. The requirements for combustion and
dilution air for appliances operating with fuels other than
fuel gas shall be regulated by Chapter 7.
C301.2 Energy utilization. Heating, ventilating and air-con-
ditioning systems of all structures shall be designed and
installed for efficient utilization of energy in accordance with
Chapter 13 in the Oregon Structural Specialty Code.
C301.3 Listed and labeled. Appliances regulated by this code
shall be listed and labeled for the application in which they are
used unless otherwise approved in accordance with Section
105.
C301.4 Fuel types. Appliances shall be designed for use with
the type of fuel gas that will be supplied to them.
€301.4.1 Appliance fuel conversion. Appliances shall not
be converted to utilize a different fuel gas except where
complete instructions for such conversion are provided in
the installation instructions, by the serving gas supplier or
by the appliance manufacturer.
SECTION C302
STRUCTURAL SAFETY
C302.1 Structural safety. See Chapter 3, Section 302.
SECTION C303
APPLIANCE LOCATION
C303.1 General. Appliances shall be located as required by
this section, specific requirements elsewhere in this appendix
and the conditions of the equipment and appliance listing.
C303.2 Hazardous locations. Appliances shall not be located
in a hazardous location unless listed and approved for the spe-
cific installation.
C303.3 Prohibited locations. Appliances shall not be located
in sleeping rooms, bathrooms, toilet rooms, storage closets or
surgical rooms, or in a space that opens only into such rooms or
spaces, except where the installation complies with one of the
following:
1. The appliance is a direct- vent appliance installed in
accordance with the conditions of the listing and the
manufacturer's instructions.
2. Vented room heaters, wall furnaces, vented decorative
appliances, vented gas fireplaces, vented gas fireplace
heaters and decorative appliances for installation in
vented solid fuel-burning fireplaces are installed in
rooms that meet the required volume criteria of Section
C304.5.
3. A single wall-mounted unvented room heater is installed
in a bathroom and such unvented room heater is
equipped as specified in Section C621 .6 and has an input
rating not greater than 6,000 Btu/h (1 .76 kW). The bath-
room shall meet the required volume criteria of Section
C304.5.
4. A single wall-mounted unvented room heater is installed
in a bedroom and such unvented room heater is equipped
as specified in Section C62 1 .6 and has an input rating not
greater than 10,000 Btu/h (2.93 kW). The bedroom shall
meet the required volume criteria of Section C304.5.
5. The appliance is installed in a room or space that opens
only into a bedroom or bathroom, and such room or
space is used for no other purpose and is provided with a
solid weather- stripped door equipped with an approved
self-closing device. All combustion air shall be taken
directly from the outdoors in accordance with Section
C304.6.
C303.4 Protection from vehicle impact damage. Appliances
shall not be installed in a location subject to vehicle impact
damage except where protected by an approved means (see
Figure C304.1).
C303.5 Indoor locations. Furnaces and boilers installed in
closets and alcoves shall be listed for such installation.
C303.6 Outdoor locations. Equipment installed in outdoor
locations shall be listed for outdoor installation. <^
C303.7 Pit locations. Appliances installed in pits or excava-
tions shall not come in direct contact with the surrounding soil.
The sides of the pit or excavation shall be held back a minimum
of 12 inches (305 mm) from the appHance. Where the depth
exceeds 12 inches (305 mm) below adjoining grade, the walls
of the pit or excavation shall be lined with concrete or masonry,
such concrete or masonry shall extend a minimum of 4 inches
(102 mm) above adjoining grade and shall have sufficient lat-
eral load-bearing capacity to resist collapse. The appliance
shall be protected from flooding in an approved manner.
SECTION C304
COMBUSTION, VENTILATION AND DILUTION AIR
C304.1 General. Air for combustion, ventilation and dilution
of flue gases for appliances installed in buildings shall be pro-
vided by application of one of the methods prescribed in Sec-
tions C304.5 through C304.9. Where the requirements of
Section C304.5 are not met, outdoor air shall be introduced in
accordance with one of the methods prescribed in Sections
C304.6 through C304.9. Direct-vent appHances, gas appli-
ances of other than natural draft design and vented gas appli-
ances other than Category I shall be provided with combustion,
ventilation and dilution air in accordance with the appliance
manufacturer's instructions.
Exception: Type 1 clothes dryers that are provided with
makeup air in accordance with Section 504.5.
C304.2 Appliance location. Appliances shall be located so as
not to interfere with proper circulation of combustion, ventila-
tion and dilution air.
2007 OREGON MECHANICAL SPECIALTY CODE
117.9
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Examples of barrier locations, when appliances are
in the path of vehicles
Minimum 2" sch. 40 iron pipe-
filled with concrete
Furnace
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Option 2:
Wheel Barrier _
Vehicle
1
For appliances not in the path of the
vehicles, this bollard is optional
Vehicle
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APPENDIX C
C304.3 Draft hood/regulator location. Where used, a draft
hood or a barometric draft regulator shall be installed in the
same room or enclosure as the appliance served so as to prevent
any difference in pressure between the hood or regulator and
the combustion air supply.
C304.4 Makeup air provisions. Makeup air requirements for
the operation of exhaust fans, kitchen ventilation systems,
clothes dryers and fireplaces shall be considered in determin-
ing the adequacy of a space to provide combustion air require-
ments.
C304.4.1 Special conditions; In buildings containing
combustion appliances, equipment or fireplaces not
equipped with forced or induced draft or separated from
the habitable area, where an individual exhaust appliance
exceeds 350 cubic feet per minute (cfm) (165.2L/s),
makeup air of sufficient quantity to equal that being
exhausted shall be supplied to the, area being ventilated.
In such cases, the minimum size makeup air duct shall be
6 inches (152 mm) in diameter or equivalent area.
C304.5 Indoor combustion air. The required volume of
indoor air shall be determined in accordance with Section
C304.5.1 or C304.5.2, except that where the air infiltration
rate is known to be less than 0.40 air changes per hour (ACH),
Section C304.5.2 shall be used. The total required volume
shall be the sum of the required volume calculated for all
appliances located within the space. Rooms communicating
directly with the space in which the appliances are installed
through openings not furnished with doors, and through com-
bustion air openings sized and located in accordance with
Section C304.5.3, are considered to be part of the required
volume.
C304.5.1 Standard method. The minimum required vol-
ume shall be 50 cubic feet per 1,000 Btu/h (4.8 m^/kW) of
the appliance input rating.
C304.5.2 Known air-infiltration-rate method. Where the
air infiltration rate of a structure is known, the minimum
required volume shall be determined as follows:
For appliances other than fan-assisted, calculate volume
using Equation 3-1.
where:
/„,ft^r = All appliances other than fan assisted (input in
Btu/h).
/^„„ = Fan-assisted appliance (input in Btu/h).
ACH = Air change per hour (percent of volume of space
exchanged per hour, expressed as a decimal).
For purposes of this calculation, an infiltration rate
greater than 0.60 ACH shall not be used in Equations 3-1
and 3-2.
C304.5.3 Indoor opening size and location. Openings
used to connect indoor spaces shall be sized and located in
accordance with Sections C304.5.3.1 and C304.5.3.2 (see
Figure C304.5. 3).
CHiMNEVWOASVENT
Water
Iwater
D
; .»__ — »— OPENING
^
I 'i ' i'i'i' i'i 'i
I I ! r I n:
FIGURE C304.5.3
ALL AIR FROM INSIDE THE BUILDING
(see Section C304.5.3)
Required Volumepther ^
21/r
ACH { 1,000 Btu/hr
(Equation 3-1)
For fan-assisted appliances, calculate volume using
Equation 3-2.
Required Volumefan
fan
ACH\ 1,000 Btu/hr
(Equation 3-2)
C304.5.3.1 Combining spaces on the same story.
Each opening shall have a minimum free area of 1
square inch per 1,000 Btu/h (2,200 mm^/kW) of the
total input rating of all appliances in the space, but not
less than 100 square inches (0.06 m^). One opening
shall commence within 12 inches (305 mm) of the top
and one opening shall commence within 12 inches (305
mm) of the bottom of the enclosure. The minimum
dimension of air openings shall be not less than 3 inches
(76 mm).
2007 OREGON MECHANICAL SPECIALTY CODE
117.11
APPENDIX C
C304.S3.2 Combining spaces in different stories. The
volumes of spaces in different stories shall be considered
as communicating spaces where such spaces are con-
nected by one or more openings in doors or floors having a
total minimum free area of 2 square inches per 1 ,000 Btu/h
(4402 mm^/kW) of total input rating of all appliances.
CWfMNeyORGASVENT
in Outdoor combustion air
shall be provided through opening(s) to the outdoors in accor-
dance with Section C304.6.1 or C304.6.2. The minimum
dimension of air openings shall be not less than 3 inches (76
mm).
C304.6.1 Two-permanent-openings method. Two perma-
nent openings, one commencing within 12 inches (305 mm)
of the top and one commencing within 12 inches (305 mm)
of the bottom of the enclosure, shall be provided. The open-
ings shall communicate directly, or by ducts, with the out-
doors or spaces that freely communicate with the outdoors.
Where directly communicating with the outdoors, or
where communicating with the outdoors through vertical
ducts, each opening shall have a minimum free area of 1
square inch per 4,000 Btu/h (550 mm^/kW) of total input
rating of all appliances in the enclosure [see Figures
C304.6.1(l) and C304.6.1(2)].
Where communicating with the outdoors through hori-
zontal ducts, each opening shall have a minimum free area
of not less than 1 square inch per 2,000 Btu/h (1,100
mm^/kW) of total input rating of all appliances in the enclo-
sure [see Figure C304.6.1(3)].
CHIMNEY OR GAS VENT
ALTERNATE
AIR INLET
OPENING TO
OUTDOORS
VENTILATION LOUVERS
(EACH END OF ATTIC)
mi
^S
M ■ r r I
IZ3
rzr
VENTILATION LOUVERS FOR^
UNHEATED CRAWL SPACE
FIGURE C304.6.1(1)
ALL AIR FROM OUTDOORS— INLET AIR FROM VENTILATED
CRAWL SPACE AND OUTLET AIR TO VENTILATED ATTIC
(see Section C304.6.1)
V^NTtUa'tOW tOUVBRS.
(EACHENOOFATnC)
OUTLET WR
JNUET AIR DUCT
<eNOStPOOT|aiSMM)
ABOVE FLOOR)
s:
till!
For SI: 1 foot = 304.8 mm.
FIGURE 0304.6.1(2)
ALL AIR FROM OUTDOORS THROUGH VENTILATED ATTIC
(see Section C304.6.1)
-CHIMNEY OR GAS VENT
rz:
rzj
FIGURE C304.6.1 (3)
ALL AIR FROM OUTDOORS
(see Section C304.6.1)
C304.6.2 One-permanent-opening method. One perma-
nent opening, commencing Within 12 inches (305 mm) of the
top of the enclosure, shall be provided. The appliance shall
have clearances of at least 1 inch (25 mm) from the sides and
back cind 6 inches (152 mm) from the front of the appliance.
The opening shall directly communicate with the outdoors or
through a vertical or horizontal duct to the outdoors, or spaces
that freely communicate with the outdoors (see Figure
C304.6.2) and shall have a minimum free area of 1 square
inch per 3,000 Btu/h (734 mm^/kW) of the total input rating
of all appliances located in the enclosure and not less than the
sum of the areas of all vent connectors in the space.
117.12
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
CHIMNEV OR GAS VEfIT
FIGURE C304.6.2
SINGLE COMBUSTION AIR OPENING,
ALL AIR FROM THE OUTDOORS
(see Section 0304.6.2)
C304.7 Combination indoor and outdoor combustion air.
The use of a combination of indoor and outdoor combustion air
shall be in accordance with Sections C304.7.1 through
C304.7.3.
C304.7.1 Indoor openings. Where used, openings con-
necting the interior spaces shall comply with Section
C304.5.3.
C304.7.2 Outdoor opening location. Outdoor opening(s)
shall be located in accordance with Section C304.6.
C304.7.3 Outdoor opening(s) size. The outdoor opening(s)
size shall be calculated in accordance with the following:
1 . The ratio of interior spaces shall be the available vol-
ume of all communicating spaces divided by the
required volume.
2. The outdoor size reduction factor shall be one minus
the ratio of interior spaces.
3. The minimum size of outdoor opening(s) shall be the
full size of outdoor opening(s) calculated in accor-
dance with Section C304.6, multiplied by the reduc-
tion factor. The minimum dimension of air openings
shall be not less than 3 inches (76 mm).
C304.8 Engineered installations. Engineered combustion air
installations shall provide an adequate supply of combustion,
ventilation and dilution air and shall be approved.
C304.9 Mechanical combustion air supply. Where all com-
bustion air is provided by a mechanical air supply system, the
combustion air shall be supplied from the outdoors at a rate not
less than 0.35 cubic feet per minute per 1,000 Btu/h (0.034
m^/min per kW) of total input rating of all appliances located
within the space.
C304.9.1 Makeup air. Where exhaust fans are installed,
makeup air shall be provided to replace the exhausted air.
C304.9.2 Appliance interlock. Each of the appliances
served shall be interlocked with the mechanical air supply
system to prevent main burner operation when the mechani-
cal air supply system is not in operation.
C304.9.3 Combined combustion air and ventilation air
system. Where combustion air is provided by the building's
mechanical ventilation system, the system shall provide the
specified combustion air rate in addition to the required ven-
tilation air.
C304.10 Louvers and grilles. The required size of openings for
combustion, ventilation and dilution air shall be based on the net
free area of each opening. Where the free area through a design
of louver, grille or screen is known, it shall be used in calculating
the size opening required to provide the free area specified.
Where the design and free area of louvers and grilles are not
known, it shall be assumed that wood louvers will have 25 -per-
cent free area and metal louvers and grilles will have 75 -percent
free area. Screens shall have a mesh size not smaller than V4 inch
(6.4 mm). Nonmotorized louvers and grilles shall be fixed in the
open position. Motorized louvers shall be interlocked with the
apphance so that they are proven to be m the full open position
prior to main burner ignition and during main burner operation.
Means shall be provided to prevent the main burner from ignit-
ing if the louvers fail to open during burner start-up and to shut
down the main burner if the louvers close during operation.
C304.ll Combustion air ducts. Combustion air ducts shall
comply with all of the following:
1 . Ducts shall be constructed of galvanized steel complying
with Chapter 6 of the Mechanical Code or of a material
having equivalent corrosion resistance, strength and
rigidity.
Exception: Within dwellings units, unobstructed
stud and joist spaces shall not be prohibited from con-
veying combustion air, provided that not more than
one required fireblock is removed.
2. Ducts shall terminate in an unobstructed space allowing
free movement of combustion air to the appliances.
3. Ducts shall serve a single enclosure.
4. Ducts shall not serve both upper and lower combustion
air openings where both such openings are used. The
separation between ducts serving upper and lower com-
bustion air openings shall be maintained to the source of
combustion air.
5. Ducts shall not be screened where terminating in an attic
space.
6. Horizontal upper combustion air ducts shall not slope
downward toward the source of combustion air.
7. The remaining space surrounding a chimney liner, gas
vent, special gas vent or plastic piping installed within a
masonry, metal or factory-built chimney shall not be
used to supply combustion air.
Exception: Direct-vent gas-fired appliances
designed for installation in a solid fuel-burning fire-
place where installed in accordance with the manu-
facturer's instructions.
2007 OREGON MECHANICAL SPECIALTY CODE
117.13
APPENDIX C
8. Combustion air intake openings located on the exterior
of a building shall have the lowest side of such openings
located not less than 12 inches (305 mm) vertically from
the adjoining grade level.
C304.12 Protection from fumes and gases. Where corrosive
or flammable process fumes or gases, other than products of
combustion, are present, means for the disposal of such fumes
or gases shall be provided. Such fumes or gases include carbon
monoxide, hydrogen sulfide, ammonia, chlorine and
halogenated hydrocarbons.
In barbershops, beauty shops and other facilities where
chemicals that generate corrosive or flammable products, such
as aerosol sprays, are routinely used, nondirect vent-type appli-
ances shall be located in a mechanical room separated or parti-
tioned off from other areas with provisions for combustion air
and dilution air from the outdoors. Direct- vent appliances shall
be installed in accordance with the appliance manufacturer's
installation instructions.
SECTBON C305
INSTALLATION
C305.1 General. Equipment and appliances shall be installed
as required by the terms of their approval, in accordance with
the conditions of listing, the manufacturer's instructions and
this code. Manufacturers' installation instructions shall be
available on the job site at the time of inspection. Where a code
provision is less restrictive than the conditions of the listing of
the equipment or appliance or the manufacturer's installation
instmctions, the conditions of the listing and the manufac-
turer's installation instructions shall apply.
Unlisted appliances approved in accordance with Section
C301 .3 shall be limited to uses recommended by the manufac-
turer and shall be installed in accordance with the manufac-
turer's instructions, the provisions of this code and the
requirements determined by the code official.
C305.2 Hazardous area. Equipment and appliances having an
ignition source shall not be installed in Group H occupancies or
control areas where open use, handling or dispensing of com-
bustible, flammable or explosive materials occurs.
C305.3 Elevation of ignition source. Heating and/or cooling
equipment and water heaters covered by this code, located in a
garage and which generate a glow, spark or flame capable of
igniting flammable vapors shall be installed with sources of
ignition at least 1 8 inches (457 mm) above the floor level.
Exception; Elevation of the ignition source is not required
for appliances that are listed as flammable vapor ignition
resistant.
C305.3.1 Parking garages. Connection of a parking
garage with any room in which there is a fuel-fired appli-
ance shall be by means of a vestibule providing a two-door-
way separation, except that a single door is permitted where
the sources of ignition in the appliance are elevated in accor-
dance with Section C305.3.
Exception: This section shall not apply to appliance
installations complying with Section C305.4.
C305.4 Public garages. Appliances located in public garages,
motor fuel-dispensing facilities, repair garages or other areas
frequented by motor vehicles shall be installed a minimum of 8
feet (2438 mm) above the floor. Where motor vehicles exceed 6
feet (1829 mm) in height and are capable of passing under an
apphance, appliances shall be installed a minimum of 2 feet (610
mm) higher above the floor than the height of the tallest vehicle.
Exception: The requirements of this section shall not apply
where the appliances are protected from motor vehicle
impact and installed in accordance with Section C305.3.
5S.S Private garages. Appliances located in private
garages shall be installed with a minimum clearance of 6 feet
(1829 mm) above the floor.
Exception: The requirements of this section shall not apply
where the appliances are protected from motor vehicle
impact and installed in accordance with Section C305.3 (see
Figure C304.1).
C30S.6 Construction and protection. Boiler rooms and fur-
nace rooms shall be protected as required by the Building
Code.
C305.7 Clearances from grade. Equipment and appliances
installed at grade level shall be supported on a level concrete
slab or other approved material extending above adjoining
grade or shall be suspended a minimum of 6 inches (152 mm)
above adjoining grade.
C30S.8 Clearances to combustible construction. Heat-pro-
ducing equipment and appliances shall be installed to maintain
the required clearances to combustible construction as speci-
fied in the listing and manufacturer's instructions. Such clear-
ances shall be reduced only in accordance with Section C308.
Clearances to combustibles shall include such considerations
as door swing, drawer pull, overhead projections or shelving
and window swing. Devices, such as door stops or limits and
closers, shall not be used to provide the required clearances.
SECTBON C306
ACCESS AND SERVICE SPACE
C306.1 Clearances for maintenance and replacement. Clear-
ances around appliances to elements of permanent construction,
including other installed appliances, shall be sufficient to allow
inspection, service, repair or replacement without removing
such elements of permanent construction or disabUng the func-
tion of a required fire-resistance-rated assembly.
C306.2 Appliances in rooms. Rooms containing appliances
requiring access shall be provided with a door and an unob-
structed passageway measuring not less than 36 inches (914
mm) wide and 80 inches (2032 mm) high.
Exception: Within a dwelling unit, appliances installed in a
compartment, alcove, basement or similar space shall be
provided with access by an opening or door and an unob-
structed passageway measuring not less than 24 inches (610
mm) wide and large enough to allow removal of the largest
appliance in the space, provided that a level service space of
not less than 30 inches (762 mm) deep and the height of the
appliance, but not less than 30 inches (762 mm), is present at
the front or service side of the appliance with the door open.
1117.14
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
C306.3 Appliances in attics. Attics containing appliances
requiring access shall be provided with an opening and
unobstructed passageway large enough to allow removal of
the largest component of the appliance. The passageway
shall not be less than 30 inches (762 mm) high and 22 inches
(559 mm) wide and not more than 20 feet (6096 mm) in
length when measured along the centerline of the passage-
way from the opening to the equipment. The passageway
shall have continuous solid flooring not less than 24 inches
(610 mm) wide. A level service space not less than 30 inches
(762 mm) deep and 30 inches (762 mm) wide shall be pres-
ent at the front or service side of the equipment. The clear
access opening dimensions shall be a minimum of 20 inches
by 30 inches (508 mm by 762 mm), where such dimensions
are large enough to allow removal of the largest component
of the appliance.
Exceptions:
1. The passageway and level service space are not
required where the appliance is capable of being
serviced and removed through the required open-
ing.
2. Where the passageway is not less than 6 feet (1829
mm) high for its entire length, the passageway shall
be not greater than 50 feet (15 250 mm) in length.
C306.3.1 Electrical requirements. A luminaire controlled
by a switch located at the required passageway opening and
a receptacle outlet shall be provided at or near the equipment
location in accordance with the Electrical Code.
C306.4 Appliances under floors. Under-floor spaces contain-
ing appliances requiring access shall be provided with an
access opening and unobstructed passageway large enough to
remove the largest component of the appliance; The passage-
way shall not be less than 30 inches (762 mm) high and 22
inches (559 mm) wide, nor more than 20 feet (6096 mm) in
length when measured along the centerline of the passageway
from the opening to the equipment. A level service space not
less than 30 inches (762 mm) deep and 30 inches (762 mm)
wide shall be present at the front or service side of the appli-
ance. If the depth of the passageway or the service space
exceeds 12 inches (305 mm) below the adjoining grade, the
walls of the passageway shall be lined with concrete or
masonry extending 4 inches (102 mm) above the adjoining
grade and having sufficient lateral-bearing capacity to resist
collapse. The clear access opening dimensions shall be a mini-
mum of 22 inches by 30 inches (559 mm by 762 mm), where
such dimensions are large enough to allow removal of the larg-
est component of the appliance.
Exceptions:
1. The passageway is not required where the level ser-
vice space is present when the access is open and the
appliance is capable of being serviced and removed
through the required opening.
2. Where the passageway is not less than 6 feet high
(1829 mm) for its entire length, the passageway shall
not be hmited in length.
C306.4.1 Electrical requirements. A luminaire controlled
by a switch located at the required passageway opening and
a receptacle outlet shall be provided at or near the equipment
location in accordance with the Electrical Code.
C306.5 Appliances on roofs or elevated structures. Where
appliances requiring access are installed on roofs or elevated
structures at a height exceeding 16 feet (4877 mm), such
access shall be provided by a permanent approved means of
access, the extent of which shall be from grade or floor level
to the appliance's level service space. Such access shall not
require climbing over obstructions greater than 30 inches
high (762 mm) or walking on roofs having a slope greater
than four units vertical in 12 units horizontal (33-percent
slope).
Exception: This section shall not apply to the replacement,
repair or maintenance of an existing appliance or piece of
equipment lawfully in existence at the time of the adoption
of this code.
Permanent ladders installed to provide the required access
shall comply with the following minimum design criteria.
1 . The side railing shall extend above the parapet or roof
edge not less than 30 inches (762 mm).
2. Ladders shall have a rung spacing not to exceed 14
inches (356 mm) on center.
3. Ladders shall have a toe spacing not less than 6 inches
(152 mm) deep.
4. There shall be a minimum of 18 inches (457 mm)
between rails.
5. Rungs shall have a minimum diameter of 0.75-inch (19
mm) and shall be capable of withstanding a 300-pound
(136.1 kg) load.
6. Ladders over 30 feet (9144 mm) in height shall be pro-
vided with offset sections and landings capable of with-
standing a load of 100 pounds per square foot (488.2
kg/m2).
7. Ladders shall be protected against corrosion by
approved means.
Catwalks installed to provide the required access shall be not
less than 24 inches wide (610 mm) and shall have railings as
required for service platforms.
Exception: This section shall not apply to Group R-3 occu-
pancies.
C306.5.1 Sloped roofs. Where apphances are installed on a
roof having a slope of three units vertical in 12 units hori-
zontal (25 -percent slope) or greater and having an edge
more than 30 inches (762 mm) above grade at such edge, a
level platform shall be provided on each side of the appli-
ance to which access is required for service, repair or main-
tenance. The platform shall not be less than 30 inches (762
mm) in any dimension and shall be provided with guards.
The guards shall extend not less than 42 inches (1067 mm)
above the platform, shall be constructed so as to prevent the
passage of a 21 -inch-diameter (533 mm) sphere and shall
comply with the loading requirements for guards specified
in the Building Code.
Exception: This section shall not apply to the replace-
ment, repair or maintenance of an existing appliance or
2007 OREGON MECHANICAL SPECIALTY CODE
117.15
APPENDIX C
piece of equipment lawfully in existence at the time of
the adoption of this code.
1.5.2 Electrical reqelrements. A receptacle outlet
shall be provided at or near the equipment location in accor-
dance with the Electrical Code.
C306.6 Guards. Guards shall be provided where appliances or
> other components that require service are located within 1 feet
(3048 mm) of a roof edge or open side of a walking surface and
such edge or open side is located more than 30 inches (762 mm)
above the floor, roof or grade below. The guard shall extend not
less than 30 inches (762 mm) beyond each end of such appli-
> ances, components and the top of the guard shall be located not
less than 42 inches (1067 mm) above the elevated surface adja-
cent to the guard. The guard shall be constructed so as to pre-
vent the passage of a 21 -inch-diameter (533 mm) sphere and
shall comply with the loading requirements for guards speci-
fied in the Building Code.
Exceptioe: This section shall not apply to the replacement,
repair or maintenance of an existing appliance or piece of
equipment lawfully in existence at the time of the adoption
of this code.
CONDENSATE DISPOSAL
Note: For addntioeal information on condensate disposal see
Chapter 3, Section 307.
C307.1 Evaporators and coolieg coils. Condensate drainage
systems shall be provided for equipment and appliances con-
taining evaporators and cooling coils in accordance with Sec-
tions 307 and C307.
C3([])7,2 Feel-bereimig appliamces. Liquid combustion
by-products of condensing appliances shall be collected and
discharged to an approved plumbing fixture or disposal area in
accordance with the manufacturer's installation instructions.
Condensate piping shall be of approved corrosion-resistant
material and shall not be smaller than the drain connection on
the appliance. Such piping shall maintain a minimum slope in
the direction of discharge of not less than one-eighth unit verti-
cal in 12 units horizontal (1 -percent slope).
C3(D)7.3 Draie pipe materials and sizes. Components of the
condensate disposal system shall be cast iron, galvanized steel,
copper, polybutylene, polyethylene, ABS, CPVC or PVC pipe
or tubing. All components shall be selected for the pressure and
temperature rating of the installation. Condensate waste and
drain line size shall be not less than ^/4-inch internal diameter
(19 mm) and shall not decrease in size from the drain connec-
tion to the place of condensate disposal. Where the drain pipes
from more than one unit are manifolded together for conden-
sate drainage, the pipe or tubing shall be sized in accordance
with an approved method. All horizontal sections of drain pip-
ing shall be installed in uniform alignment at a uniform slope.
C3(0)7.4 Traps. Condensate drains shall be trapped as required
by the equipment or appliance manufacturer.
C3(D7.5 Auxiliary drain pan. Category IV condensing appli-
ances shall be provided with an auxiliary drain pan where dam-
age to any building component will occur as a result of stoppage
in the condensate drainage system. Such pan shall be installed in
accordance with the applicable provisions of Section C307.
Exception: An auxiliary drain pan shall not be required for
appliances that automatically shut down operation in the
event of a stoppage in the condensate drainage system.
SECTION C308
CLEARANCE REDUCTION
C308.1 Scope. This section shall govern the reduction in
required clearances to combustible materials and combustible
assemblies for chimneys, vents, appliances, devices and equip-
ment. Clearance requirements for gas-fired air-conditioning
equipment and gas-fired central heating boilers and furnaces
shall comply with Sections C308.3 and C308.4.
C308.2 Reduction table. The allowable clearance reduction
shall be based on one of the methods specified in Table C308.2
or shall utilize an assembly listed for such application. Where
required clearances are not listed in Table C308.2, the reduced
clearances shall be determined by linear inte]*polation between
the distances listed in the table. Reduced cleai^ances shall not be
derived by extrapolation below the range of the table. The
reduction of the required clearances to combustibles for listed
and labeled appliances and equipment shall be in accordance
with the requirements of this section except that such clear-
ances shall not be reduced where reduction is specifically pro-
hibited by the terms of the apphance or equipment listing [see
Figures C308.2(l) through C308.2(3)].
C308.3 Clearances for indoor air-conditioning appliances.
Clearance requirements for indoor air-conditioning appliances
shall comply with Sections C308.3.1 through C308.3.5.
C308.3.1 Appliances installed in rooms that are large in
comparison with the size of the appliance. Air-condition-
ing appliances installed in rooms that are large in comparison
with the size of the appliance shall be installed with clear-
ances in accordance with the manufacturer's instructions.
C308.3.2 Appliances installed in rooms that are not large
in comparison with the size of the appliance. Air-condi-
tioning appliances installed in rooms that are not large in
comparison with the size of the appliance, such as alcoves
and closets, shall be listed for such installations and installed
in accordance with the manufacturer's instructions. Listed
clearances shall not be reduced by the protection methods
described in Table C308.2, regardless of whether the enclo-
sure is of combustible or noncombustible material.
C308.3.3 Clearance reduction. Air-conditioning appli-
ances installed in rooms that are large in comparison with
the size of the appliance shall be permitted to be installed
with reduced clearances to combustible material, provided
the combustible material or appliance is protected as
described in Table C308.2.
C308.3.4 Plenum clearances. Where the furnace plenum is
adjacent to plaster on metal lath or noncombustible material
attached to combustible material, the cleariince shall be mea-
sured to the surface of the plaster or other noncombustible fin-
ish where the clearance specified is 2 inches (5 1 mm) or less.
117.16
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C308.2^ **"°"^*' "
REDUCTION OF CLEARANCES WITH SPECIFIED FORMS OF PROTECTION
TYPE OF PROTECTION APPLIED TO
AND COVERING ALL SURFACES OF COMBUSTIBLE
MATERIAL WITHIN THE DISTANCE SPECIFIED AS THE
REQUIRED CLEARANCE WITH NO PROTECTION
[see Figures C308.2(1), C308.2(2), and C308.2(3)]
WHERE THE REQUIRED CLEARANCE WITH NO PROTECTION FROM
APPLIANCE, VENT CONNECTOR, OR SINGLE-WALL METAL PIPE IS: (inches)
36
18
12
9
6
Allowable clearances with specified protection (inches)
Use Column 1 for clearances above appliance or horizontal connector. Use Column 2
for clearances from appliance, vertical connector, and single-wall metal pipe.
Above
Col. 1
Sides
and rear
Col. 2
Above
Col. 1
Sides
and rear
Col. 2
Above
Col. 1
Sides
and rear
Col. 2
Above
Col. 1
Sides
and rear
Col. 2
Above
Col. 1
Sides
and rear
Col. 2
1. 3 'A- inch-thick masonry wall without ventilated air-
space
—
24
—
12
—
9
—
6
5
2. '/2-inch insulation board over 1-inch glass fiber or
mineral wool batts
24
18
12
9
9
6
6
5
4
3
3 . 0.024-inch (nominal 24 gage) sheet metal over 1 -inch
glass fiber or mineral wool batts reinforced with wire
on rear face with ventilated airspace
18
12
9
6
6
4
5
3
3
3
4. S'A-inch-thick masonry wall with ventilated air-
space
—
12
—
6
—
6
—
6
6
5. 0.024-inch (nominal 24 gage) sheet metal with ven-
tilated airspace
18
12
9
6
6
4
5
3
3
2
6. '/2-inch-thick insulation board with ventilated air-
space
18
12
9
6
6
4
5
3
3
3
7. 0.024-inch (nominal 24 gage) sheet metal with ven-
tilated airspace over 0.024-inch (nominal 24 gage)
sheet metal with ventilated airspace
18
12
9
6
6
4
5
3
3
3
8. 1 -inch glass fiber or mineral wool batts sandwiched
between two sheets 0.024-inch (nominal 24 gage)
sheet metal with ventilated airspace
18
12
9
6
6
4
5
3
3
3
For SI: 1 inch = 25.4 mm, °C = [(°F - 32)/1.8], 1 pound per cubic foot = 16.02 kgti\ I Btu per inch per square foot per hour per °F = 0.144 WAn^ x K.
a. Reduction of clearances from combustible materials shall not interfere with combustion air, draft hood clearance and relief, and accessibility of servicing.
b. All clearances shall be measured from the outer surface of the combustible material to the nearest point on the surface of the appliance, disregarding any interven-
ing protection applied to the combustible material.
c. Spacers and ties shall be of noncombustible material. No spacer or tie shall be used directly opposite an appliance or connector
d. For all clearance reduction systems using a ventilated airspace, adequate provision for air circulation shall be provided as described [see Figures C308.2(2) and
C308.2(3)].
e. There shall be at least 1 inch between clearance reduction systems and combustible walls and ceilings for reduction systems using ventilated airspace.
f. Where a wall protector is mounted on a single flat wall away from comers, it shall have a minimum 1-inch air gap. To provide air circulation, the bottom and top
edges, or only the side and top edges, or all edges shall be left open.
g. Mineral wool batts (blanket or board) shall have a minimum density of 8 pounds per cubic foot and a minimum melting point of 1500°E
h. Insulation material used as part of a clearance reduction system shall have a thermal conductivity of 1.0 Btu per inch per square foot per hour per °F or less.
i. There shall be at least 1 inch between the appliance and the protector In no case shall the clearance between the appliance and the combustible surface be reduced
below that allowed in this table,
j. All clearances and thicknesses are minimum; larger clearances and thicknesses are acceptable,
k. Listed single-wall connectors shall be installed in accordance with the manuiacturer's installation instructions.
•
2007 OREGON MECHANICAL SPECIALTY CODE
117.17
APPENDIX C
CONSTRUCTION USING COMBUSTIBLE-
MATERIAL, PLASTERED OR UNPLASTERED
SHEET METAL
OR OTHER
PROTECTION
"A" equals the reduced clearance with no protection.
"B" equals the reduced clearance permitted in accordance with Table
C308.2. The protection applied to the construction using combustible
material shall extend far enough in each direction to make "C" equal
to "A."
FIGURE C308.2(1)
EXTENT OF PROTECTION NECESSARY TO
REDUCE CLEARANCES FROM APPLIANCE OR
VENT CONNECTIONS
1-INCH MINIMUM
AIRSPACE BETWEEN
MASONRY AND
COMBUSTIBLE WALL
COMBUSTIBLE WALL
BOnOM AND TOP COURSE
OF BRICKS STAGGERED
FOR VENTILATION
A STRIP OF HEAVY-GAUGE STEEL
USED FOR ADDED SUPPORT
NOTE: DO NOT PUCE MASONRY
WALL TIES DIRECTLY BEHIND
APPLIANCE OR CONNECTOR
For SI: 1 inch = 25.4 mm.
CORRUGATED
METAL WALL
TIES
FIGURE C308.2(3)
MASONRY CLEARANCE REDUCTION SYSTEM
\NALl PROTECTOR MOUNTED
WITH ALL EDGES OPEN
WALL PROTECTOR MOUNTED
ON SINGLE FLAT WALL
MUST BE MOUNTED
WITH TOP AND BOTTOM
EDGES OPEN
WALL PROTECTOR INSTALLED
IN CORNER
MOUNTED WITH SIDE
AND TOP EDGES OPEN
MOUNTED WITH TOP
AND BOTTOM EDGES
OPEN
-^^
COMBUSTIBLE
WALL
^
1 INCH
AIR-
SPACE
^Omw^m '
]-
NAIL OR SCREW
ANCHOR
CLEARANCE
REDUCTION SYSTEM
1-INCH NONCOMBUSTIBLE SPACER SUCH AS STACKED WASHERS, SMALL-
DIAMETER PIPE, TUBING OR ELECTRICAL CONDUIT.
For SI: 1 inch = 25.4 mm.
MASONRY WALLS CAN BE ATTACHED TO COMBUSTIBLE WALLS USING WALL TIES.
DO NOT USE SPACERS DIRECTLY BEHIND APPLIANCE OR CONNECTOR.
FIGURE C308.2(2)
WALL PROTECTOR CLEARANCE REDUCTION SYSTEM
117.18
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
C308.3.5 Clearance from supply ducts. Air-conditioning
appliances shall have the clearance from supply ducts
within 3 feet (914 mm) of the furnace plenum be not less
than that specified from the furnace plenum. Clearance is
not necessary beyond this distance.
A Central-heating boilers and furnaces. Clearance
requirements for central-heating boilers and furnaces shall
comply with Sections C308.4.1 through C308.4.6. The clear-
ance to these appliances shall not interfere with combustion air;
draft hood clearance and relief; and accessibility for servicing.
C308.4.1 Appliances installed in rooms that are large in
comparison with the size of the appliance. Central-heat-
ing furnaces and low-pressure boilers installed in rooms
large in comparison with the size of the appliance shall be
installed with clearances in accordance with the manufac-
turer's instructions.
C308.4.2 Appliances installed in rooms that are not lai^e
in comparison with the size of the appliance. Central-heat-
ing furnaces and low-pressure boilers installed in rooms that
are not large in comparison with the size of the appliance,
such as alcoves and closets, shall be listed for such installa-
tions. Listed clearances shall not be reduced by the protection
methods described in Table C308.2 and illustrated in Figures
C308.2(l) through C308.2(3), regardless of whether the
enclosure is of combustible or noncombustible material.
C308.4.3 Clearance reduction. Central-heating furnaces
and low-pressure boilers installed in rooms that are large in
comparison with the size of the appliance shall be permitted
to be installed with reduced clearances to combustible mate-
rial provided the combustible material or appliance is pro-
tected as described in Table C308.2.
C308.4.4 Clearance for servicing appliances. Front clear-
ance shall be sufficient for servicing the burner and the fur-
nace or boiler.
C3(Ii8.4.5 Plenum clearances. Where the furnace plenum is
adjacent to plaster on metal lath or noncombustible material
attached to combustible material, the clearance shall be mea-
sured to the surface of the plaster or other noncombustible fin-
ish where the clearance specified is 2 inches (5 1 mm) or less.
C308.4.6 Clearance from supply ducts. Central-heating
furnaces shall have the clearance from supply ducts within 3
feet (914 mm) of the furnace plenum be not less than that
specified from the furnace plenum. No clearance is neces-
sary beyond this distance.
SECTION C309
ELECTRICAL
C309.1 Grounding, Gas piping shall not be used as a ground-
ing electrode.
C309.2 Connections. Electrical connections between equip-
ment and the building wiring, including the grounding of the
equipment, shall conform to the Electrical Code.
SECTION C310
ELECTRICAL BONDING
C310.1 Gas pipe bonding. Each above-ground portion of a gas
piping system that is likely to become energized shall be electri-
cally continuous and bonded to an effective ground-fault current
path. Gas piping shall be considered to be bonded where it is
connected to appliances that are connected to the equipment
grounding conductor of the circuit supplying that appliance.
SECTION C401
GENERAL
C401.1 Scope. This section shall govern the installation and
modification of piping systems. The applicability of this code
to piping systems extends from the point of delivery to the con-
nections with the equipment and includes the design, materials,
components, fabrication, assembly, installation, testing and
inspection of such piping systems.
C401.1.1 Utility piping systems located within buildings.
Utility service piping located within buildings shall be
installed in accordance with the structural safety and fire
protection provisions of the Building Code.
C401.2 Liquefied petroleum gas storage. The storage system
for liquefied petroleum gas shall be designed and installed in
accordance with the Fire Code and NFPA 58.
C401.2.1 Notice of installation. A "Notice of Installation"
is required by the State Fire Marshal for all LP-gas tank
installations. For installation requirements of LP-gas tanks
and tubing or piping up to the first stage regulator, see Chap-
ter 38 of the Fire Code.
C401.3 Modifications to existing systems. In modifying or
adding to existing piping systems, sizes shall be maintained in
accordance with this chapter.
C401.4 Additional appliances. Where an additional apph-
ance is to be served, the existing piping shall be checked to
determine if it has adequate capacity for all appliances served.
If inadequate, the existing system shall be enlarged as required
or separate piping of adequate capacity shall be provided.
C401.5 Identification. For other than steel pipe, exposed pip-
ing shall be identified by a yellow label marked "Gas" in black
letters. The marking shall be spaced at intervals not exceeding
5 feet (1524 mm). The marking shall not be required on pipe
located in the same room as the equipment served.
C401.6 Interconnections. Where two or more meters are
installed on the same premises but supply separate consumers,
the piping systems shall not be interconnected on the outlet side
of the meters.
C401.7 Piping meter identification. Piping from multiple
meter installations shall be marked with an approved perma-
nent identification by the installer so that the piping system
supplied by each meter is readily identifiable.
C401.8 Minimum sizes. All pipe utilized for the installation,
extension and alteration of any piping system shall be sized to
supply the full number of outlets for the intended purpose and
shall be sized in accordance with Section C402.
<
<
2007 OREGON MECHANICAL SPECIALTY CODE
117.19
APPENDIX C
>
PIPE SIZING
€402,1 General considerations. Piping systems shall be of
such size and so installed as to provide a supply of gas suffi-
cient to meet the maximum demand without undue loss of pres-
sure between the point of delivery and the appliance.
C402.2 Maximum gas demand., The volume of gas to be pro-
vided, in cubic feet per hour, shall be determined directly from
the manufacturer's input ratings of the appliances served.
Where an input rating is not indicated, the gas supplier, appli-
ance manufacturer or a qualified agency shall be contacted, or
the rating from Table C402.2 shall be used for estimating the
volume of gas to be supplied.
The total connected hourly load shall be used as the basis for
pipe sizing, assuming that all appliances could be operating at
full capacity simultaneously. Where a diversity of load can be
established, pipe sizing shall be permitted to be based on such
loads.
C4023 Sizing. Gas piping shall be sized in accordance with
one of the following:
1. Pipe sizing tables or sizing equations in accordance with
Section C402.4.
2. The sizing tables included in a listed piping system's
manufacturer's installation instructions.
3. Other approved methods.
C402.4 Sizing tables and equations. Where Tables C402.4(l)
through C402.4(35) are used to size piping or tubing, the pipe
length shall be determined in accordance with Section
C402.4.1, C402.4.2 or C402.4.3.
Where Equations 4-1 and 4-2 are used to size piping or tub-
ing, the pipe or tubing shall have smooth inside walls and the
pipe length shall be determined in accordance with Section
C402.4.1, C402.4.2 or C402.4.3.
1. Low-pressure gas equation [Less than 1.5 pounds per
square inch (psi) (10.3 kPa)]:
TABLE C402.2
APPROXIMATE GAS INPUT FOR TYPICAL APPLIANCES
D =
Q'
19.17
AH
CxL
(Equation 4-1)
2. High-pressure gas equation [1.5 psi (10.3 kPa) and
above]:
D =
Q'
18.93
P,'-F.'llx7l
(Equation 4-2)
C.xL
where:
D = Inside diameter of pipe, inches (mm).
APPLIANCE
INPUT BTU/H
(Approx.)
Space Heating Units
Hydronic boiler
Single family
Multifamily, per unit
Warm-air furnace
Single family
Multifamily, per unit
100,000
60,000
100,000
60,000
Space and Water Heating Units
Hydronic boiler
Single family
Multifamily, per unit
120,000
75,000
Water Heating Appliances
Water heater, automatic instantaneous
Capacity at 2 gal./minute
Capacity at 4 gal./minute
Capacity at 6 gal./minute
Water heater, automatic storage, 30-to 40-gal. tank
Water heater, automatic storage, 50-gal. tank
Water heater, domestic, circulating or side-arm
142,800
285,000
428,400
35,000
50,000
^ 35,000
Cooking Appliances
Built-in oven or broiler unit, domestic
Built-in top unit, domestic
Range, free-standing, domestic
25,000
40,000
65,000
Other Appliances
Barbecue
Clothes dryer. Type 1 (domestic)
Gas fireplace, direct-vent
Gas light
Gas log
Refrigerator
40,000
35,000
40,000
2,500
80,000
3,000
For SI: 1 British thermal unit per hour = 0.293 W, 1 gallon = 3.785 L,
1 gallon per minute = 3.785 L/m.
Q = Input rate appliance(s), cubic feet per hour at 60°F
(16°C) and 30-inch mercury column
P, = Upstream pressure, psia (P^ + 14.7)
Pj = Downstream pressure, psia (P2 + 14.7)
L = Equivalent length of pipe, feet
AH = Pressure drop, inch water column (27.7 inch water col-
umn = 1 psi)
TABLE C402.4
C, AND y VALUES FOR NATURAL GAS AND
UNDILUTED PROPANE AT STANDARD CONDITIONS
GAS
EQUATION FACTORS
Cr
/
Natural gas
0.6094
0.9992
Undiluted propane
1.2462
0.9910
For SI: 1 cubic foot = 0.028 m^, 1 foot = 305 mm, 1-inch water column =
0.249 kPa, 1 pound per square inch = 6.895 kPa, 1 British thermal
unit per hour = 0.293 W.
117.20
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
C402.4.1 Longest length method. The pipe size of each
section of gas piping shall be determined using the longest
length of piping from the point of delivery to the most
remote outlet and the load of the section.
C402.4.2 Branch length method. Pipe shall be sized as fol-
lows:
1 . Pipe size of each section of the longest pipe run from
the point of delivery to the most remote outlet shall be
determined using the longest run of piping and the
load of the section.
2. The pipe size of each section of branch piping not
previously sized shall be determined using the
length of piping from the point of delivery to the
most remote outlet in each branch and the load of the
section.
C402.4.3 Hybrid pressure. The pipe size for each section
of higher pressure gas piping shall be determined using the
longest length of piping from the point of delivery to the
most remote line pressure regulator. The pipe size from the
line pressure regulator to each outlet shall be determined
using the length of piping from the regulator to the most
remote outlet served by the regulator.
C402,5 Allowable pressure drop. The design pressure loss in
any piping system under maximum probable flow conditions,
from the point of delivery to the inlet connection of the
appliance, shall be such that the supply pressure at the appli-
ance is greater than the minimum pressure required for proper
appliance operation.
C402.6 Maximum design operating pressure. The maxi-
mum design operating pressure for piping systems located
inside buildings shall not exceed 5 pounds per square inch
gauge (psig) (34 kPa gauge) except where one or more of the
following conditions are met:
1. The piping system is welded.
2. The piping is located in a ventilated chase or otherwise
enclosed for protection against accidental gas accumula-
tion.
3 . The piping is located inside buildings or separate areas of
buildings used exclusively for:
3.1. Industrial processing or heating;
3.2. Research;
3.3. Warehousing; or
3.4. Boiler or mechanical rooms.
4. The piping is a temporary installation for buildings under
construction.
C402.6.1 Liquefied petroleum gas systems. The operating
pressure for undiluted LP-gas systems shall not exceed 20
psig (140 kPa gauge). Buildings having systems designed to
operate below -5°F (-21°C) or with butane or a pro-
pane-butane mix shall be designed to either accommodate
liquid LP-gas or prevent LP-gas vapor from condensing into
a Uquid.
Exception: Buildings or separate areas of buildings con-
structed in accordance with Chapter 10 of NFPA 58 and
used exclusively to house industrial processes, research
and experimental laboratories, or equipment or process-
ing having similar hazards.
C402.6.2 License requirements. LP-gas installers must be
licensed by the State Fire Marshal in accordance with ORS
480.432 through 480.436.
2007 OREGON MECHANICAL SPECIALTY CODE
117.21
APPENDIX C
TABLE C402.4(1)
SCHEDULE 40 METALLIC PIPE
Gas
Natural
Inlet Pressure
Less than 2 psi
Pressure Drop
0.3 in. w.c.
Specific Gravity
0.60
PIPE SIZE (inch)
Nominal
%
\
1
1V4
l'/2
2
2V2
3
4
5
6
8
10
12
Actual ID
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
5.047
6.065
7.981
10.020
11.938
Length (ft)
Capacity in Cubic Feet of Gas Per Hour
10
131
273
514
1,060
1,580
3,050
4,860
8,580
17,500
31,700
51,300
105,000
191,000
303,000
20
90
188
353
726
1,090
2,090
3,340
5,900
12,000
21,800
35,300
72,400
132,000
208,000
30
72
151
284
583
873
1,680
2,680
4,740
9,660
17,500
28,300
58,200
106,000
167,000
40
62
129
243
499
747
1,440
2,290
4,050
8,270
15,000
24,200
49,800
90,400
143,000
50
55
114
215
442
662
1,280
2,030
3,590
7,330
13,300
21,500
44,100
80,100
127,000
60
50
104
195
400
600
1,160
1,840
3,260
6,640
12,000
19,500
40,000
72,600
115,000
70
46
95
179
368
552
1,060
1,690
3,000
6,110
11,100
17,900
36,800
66,800
106,000
80
42
89
167
343
514
989
1,580
2,790
5,680
10,300
16,700
34,200
62,100
98,400
90
40
83
157
322
482
928
1,480
2,610
5,330
9,650
15,600
32,100
58,300
92,300
100
38
79
148
304
455
877
1,400
2,470
5,040
9,110
14,800
30,300
55,100
87,200
125
33
70
131
269
403
777
1,240
2,190
4,460
8,080
13,100
26,900
48,800
77,300
150
30
63
119
244
366
704
1,120
1,980
4,050
7,320
11,900
24,300
44,200
70,000
175
28
58
109
224
336
648
1,030
1,820
3,720
6,730
10,900
22,400
40,700
64,400
200
26
54
102
209
313
602
960
1,700
3,460
6,260
10,100
20,800
37,900
59,900
250
23
48
90
185
277
534
851
1,500
3,070
5,550
8,990
18,500
33,500
53,100
300
21
43
82
168
251
484
771
1,360
2,780
5,030
8,150
16,700
30,400
48,100
350
19
40
75
154
231
445
709
1,250
2,560
4,630
7,490
15,400
28,000
44,300
400
18
37
70
143
215
414
660
1,170
2,380
4,310
6,970
14,300
26,000
41,200
450
17
35
66
135
202
389
619
1,090
2,230
4,040
6,540
13,400
24,400
38,600
500
16
33
62
127
191
367
585
1,030
2,110
3,820
6,180
12,700
23,100
36,500
550
15
31
59
121
181
349
556
982
2,000
3,620
5,870
12,100
21,900
34,700
600
14
30
56
115
173
333
530
937
1,910
3,460
5,600
11,500
20,900
33,100
650
14
29
54
110
165
318
508
897
1,830
3,310
5,360
11,000
20,000
31,700
700
13
27
52
106
159
306
488
862
1,760
3,180
5,150
10,600
19,200
30,400
750
13
26
50
102
153
295
470
830
1,690
3,060
4,960
10,200
18,500
29,300
800
12
26
48
99
148
285
454
802
1,640
2,960
4,790
9,840
17,900
28,300
850
12
25
46
95
143
275
439
776
1,580
2,860
4,640
9,530
17,300
27,400
900
11
24
45
93
139
267
426
752
1,530
2,780
4,500
9,240
16,800
26,600
950
11
23
44
90
135
259
413
731
1,490
2,700
4,370
8,970
16,300
25,800
1,000
11
23
43
87
131
252
402
711
1,450
2,620
4,250
8,720
15,800
25,100
1,100
10
21
40
83
124
240
382
675
1,380
2,490
4,030
8,290
15,100
23,800
1,200
NA
20
39
79
119
229
364
644
1,310
2,380
3,850
7,910
14,400
22,700
1,300
NA
20
37
76
114
219
349
617
1,260
2,280
3,680
7,570
13,700
21,800
1,400
NA
19
35
73
109
210
335
592
1,210
2,190
3,540
7,270
13,200
20,900
1,500
NA
18
34
70
105
203
323
571
1,160
2,110
3,410
7,010
12,700
20,100
1,600
NA
18
33
68
102
196
312
551
1,120
2,030
3,290
6,770
12,300
19,500
1,700
NA
17
32
66
98
189
302
533
1,090
1,970
3,190
6,550
11,900
18,800
1,800
NA
16
31
64
95
184
293
517
1,050
1,910
3,090
6,350
11,500
18,300
1,900
NA
16
30
62
93
178
284
502
1,020
1,850
3,000
6,170
11,200
17,700
2,000
NA
16
29
60
90
173
276
488
1,000
1,800
2,920
6,000
10,900
17,200
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit|per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m'/h, 1 degree = 0.01745 rad.
Notes:
1 . NA means a flow of less than lO cfh.
2. All table entries have been rounded to three significant digits.
117.22
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C402.4(2)
SCHEDULE 40 METALLIC PIPE
Gas
Natural
Inlet Pressure
Less than 2 psi
Pressure Drop
O.i
in. w.c.
Specific Gravity
0.60
PIPE
SIZE (inch)
Nominal
'/2
\
1
l'/4
iV,
2
2'/2
3
4
5
6
8
10
12
Actual ID
0.622
0.824
1.049
i.380
1.610
2.067
2.469
3.068
4.026
5.047
6.065
7.981
10.020
11.938
Length (ft)
Capacity
in Cubic Feet of Gas Per Hour
10
172
360
678
1,390
2,090
4,020
6,400
11,300
23,100
41,800
67,600
139,000
252,000
399,000
20
118
247
466
957
1,430
2,760
4,400
7,780
15,900
28,700
46,500
95,500
173,000
275,000
30
95
199
374
768
1,150
2,220
3,530
6,250
12,700
23,000
37,300
76,700
139,000
220,000
40
81
170
320
657
985
1,900
3,020
5,350
10,900
19,700
31,900
65,600
119,000
189,000
50
72
151
284
583
873
1,680
2,680
4,740
9,660
17,500
28,300
58,200
106,000
167,000
60
65
137
257
528
791
1,520
2,430
4,290
8,760
15,800
25,600
52,700
95,700
152,000
70
60
126
237
486
728
1,400
2,230
3,950
8,050
14,600
23,600
48,500
88,100
139,000
80
56
117
220
452
677
1,300
2,080
3,670
7,490
13,600
22,000
45,100
81,900
130,000
90
52
110
207
424
635
1,220
1,950
3,450
7,030
12,700
20,600
42,300
76,900
122,000
100
50
104
195
400
600
1,160
1,840
3,260
6,640
12,000
19,500
40,000
72,600
1 15,000
125
44
92
173
355
532
1,020
1,630
2,890
5,890
10,600
17,200
35,400
64,300
102,000
150
40
83
157
322
482
928
1,480
2,610
5,330
9,650
15,600
32,100
58,300
92,300
175
37
77
144
296
443
854
1,360
2,410
4,910
8,880
14,400
29,500
53,600
84,900
200
34
71
134
,275
412
794
1,270
2,240
4,560
8,260
13,400
27,500
49,900
79,000
250
30
63
119
244
366
704
1,120
1,980
4,050
7,320
11,900
24,300
44,200
70,000
300
27
57
108
221
331
638
1,020
1,800
3,670
6,630
10,700
22,100
40,100
63,400
350
25
53
99
203
305
587
935
1,650
3,370
6,100
9,880
20,300
36,900
58,400
400
23
49
92
189
283
546
870
1,540
3,140
5,680
9,190
18,900
34,300
54,300
450
22
46
86
177
266
512
816
1,440
2,940
5,330
8,620
17,700
32,200
50,900
500
21
43
82
168
251
484
771
1,360
2,780
5,030
8,150
16,700
30,400
48,100
550
20
41
78
159
239
459
732
1,290
2,640
4,780
7,740
15,900
28,900
45,700
600
19
39
74
152
228
438
699
1,240
2,520
4,560
7,380
15,200
27,500
43,600
650
18
38
71
145
218
420
669
1,180
2,410
4,360
7,070
14,500
26,400
41,800
700
17
36
68
140
209
403
643
1,140
2,320
4,190
6,790
14,000
25,300
40,100
750
17
35
66
135
202
389
619
1,090
2,230
4,040
6,540
13,400
24,400
38,600
800
16
34
63
130
195
375
598
1,060
2,160
3,900
6,320
13,000
23,600
37,300
850
16
33
61
126
189
363
579
1,020
2,090
3,780
6,110
12,600
22,800
36,100
900
15
32
59
122
183
352
561
992
2,020
3,660
5,930
12,200
22,100
35,000
950
15
31
58
118
178
342
545
963
1,960
3,550
5,760
11,800
21,500
34,000
1,000
14
30
56
115
173
333
530
937
1,910
3,460
5,600
11,500
20,900
33,100
1,100
14
28
53
109
164
316
503
890
1,810
3,280
5,320
10,900
19,800
31,400
1,200
13
27
51
104
156
301
480
849
1,730
3,130
5,070
10,400
18,900
30,000
1,300
12
26
49
100
150
289
460
813
1,660
3,000
4,860
9,980
18,100
28,700
1,400
12
25
47
96
144
277
442
781
1,590
2,880
4,670
9,590
17,400
27,600
1,500
11
24
45
93
139
267
426
752
1,530
2,780
4,500
9,240
16,800
26,600
1,600
11
23
44
89
134
258
411
727
1,480
2,680
4,340
8,920
16,200
25,600
1,700
11
22
42 ■
86
130
250
398
703
1,430
2,590
4,200
8,630
15,700
24,800
1,800
10
22
41
84
126
242
386
682
1,390
2,520
4,070
8,370
. 15,200
24,100
1,900
10
21
40
81
122
235
375
662
1,350
2,440
3,960
8,130
14,800
23,400
2,000
NA
20
39
79
119
229
364
644
1,310
2,380
3,850
7,910
14,400
22,700
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch - 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m'/h, 1 degree = 0.01745 rad.
Notes:
1 . NA means a flow of less than 1 cfh.
2. All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.23
APPENDIX C
TABLE C402.4(3)
SCHEDULE 40 METALLIC PIPE
Gas
Natural
Inlet Pressure
2.0 psi
Pressure Drop
1 .0 psi
Specific Gravity
0.60
PIPE SIZE (inch)
Nominal
'/2
^4
1
l'/4
IV2
2
2V2
3
4
Actual ID
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
Length (ft)
Capacity in Cubic Feet of Gas Per Hour
10
1,510
3,040
5,560
11,400
17,100
32,900
52,500
92,800
189,000
20
1,070
2,150
3,930
8,070
12,100
23,300
37,100
65,600
134,000
30
869
1,760
3,210
6,590
9,880
19,000
30,300
53,600
109,000
40
753
1,520
2,780
5,710
8,550
16,500
26,300
46,400
94,700
50
673
1,360
2,490
5,110
7,650
14,700
23,500
41,500
84,700
60
615
1,240
2,270
4,660
6,980
13,500
21,400
37,900
77,300
70
569
1,150
2,100
4,320
6,470
12,500
19,900
35,100
71,600
80
532
1,080
1,970
4,040
6,050
11,700
18,600
32,800
67,000
90
502
1,010
1,850
3,810
5,700
11,000
17,500
30,900
63,100
100
462
934
1,710
3,510
5,260
10,100
16,100
28,500
58,200
125
414
836
1,530
3,140
4,700
9,060
14,400
25,500
52,100
150
372
751
1,370
2,820
4,220
8,130
13,000
22,900
46,700
175
344
695
1,270
2,601
3,910
7,530
12,000
21,200
43,300
200
318
642
1,170
2,410
3,610
6,960
11,100
19,600
40,000
250
279
583
1,040
2,140
3,210
6,180
9,850
17,400
35,500
300
253
528
945
1,940
2,910
5,600
8,920
15,800
32,200
350
232
486
869
1,790
2,670
5,150
8,210
14,500
29,600
400
216
452
809
1,660
2,490
4,790
7,640
13,500
27,500
450
203
424
759
1,560
2,330
4,500
7,170
12,700
25,800
500
192
401
717
1,470
2,210
4,250
6,770
12,000
24,400
550
182
381
681
1,400
2,090
4,030
6,430
11,400
23,200
600
174
363
650
1,330
2,000
3,850
6,130
10,800
22,100
650
166
348
622
1,280
1,910
3,680
5,870
10,400
21,200
700
160
334
598
1,230
1,840
3,540
5,640
9,970
20,300
750
154
322
576
1,180
1,770
3,410
5,440
9,610
19,600
800
149
311
556
1,140
1,710
3,290
5,250
9,280
18,900
850
144
301
538
1,100
1,650
3,190
5,080
8,980
18,300
900
139
292
522
1,070
1,600
3,090
4,930
8,710
17,800
950
135
283
507
1,040
1,560
3,000
4,780
8,460
17,200
1,000
132
275
493
1,010
1,520
2,920
4,650
8,220
16,800
1,100
125
262
468
960
1,440
2,770
4,420
7,810
15,900
1,200
119
250
446
917
1,370
2,640
4,220
7,450
15,200
1,300
114
239
427
878
1,320
2,530
4,040
7,140
14,600
1,400
110
230
411
843
1,260
2,430
3,880
6,860
14,000
1,500
106
221
396
812
1,220
2,340
3,740
6,600
13,500
1,600
102
214
382
784
1,180
2,260
3,610
6,380
13,000
1,700
99
207
370
759
1,140
2,190
3,490
6,170
12,600
1,800
96
200
358
736
1,100
2,120
3,390
5,980
12,200
1,900
93
195
348
715
1,070
2,060
3,290
5,810
11,900
2,000
91
189
339
695
1,040
2,010
3,200
5,650
11,500
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1 -inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m'/h, 1 degree = 0.01745 rad.
Note: All table entries have been rounded to three significant digits.
117.24
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C402.4(4)
SCHEDULE 40 METALLIC PIP
E
Gas
Natural
Inlet Pressure
3.0 psi
Pressure Drop
2.0 psi
Specific Gravity
0.60
PIPE SIZE (inch)
Nominal
V2
%
1
IV4
l'/2
2
2V2
3
4
Actual ID
0.622
0.824
1.049
1.380
1.610
2;067
2.469
3.068
4.026
Length (ft)
Capacity in Cubic Feet of Gas Per Hour
10
2,350
4,920
9,270
19,000
28,500
54,900
87,500
155,000
316,000
20
1,620
3,380
6,370
13,100
19,600
37,700
60,100
106,000
217,000
30
1,300
2,720
5,110
10,500
15,700
30,300
48,300
85,400
174,000
40
1,110
2,320
4,380
8,990
13,500
25,900
41,300
73,100
149,000
50
985
2,060
3,880
7,970
11,900
23,000
36,600
64,800
132,000
60
892
1,870
3,520
7,220
10,800
20,800
33,200
58,700
120,000
70
821
1,720
3,230
6,640
9,950
19,200
30,500
54,000
110,000
80
764
1,600
3,010
6,180
9,260
17,800
28,400
50,200
102,000
90
717
1,500
2,820
5,800
8,680
16,700
26,700
47,100
96,100
100
677
1,420
2,670
5,470
8,200
15,800
25,200
44,500
90,800
125
600
1,250
2,360
4,850
7,270
14,000
22,300
39,500
80,500
150
544
1,140
2,140
4,400
6,590
12,700
20,200
35,700
72,900
175
500
1,050
1,970
4,040
6,060
11,700
18,600
32,900
67,100
200
465
973
1,830
3,760
5,640
10,900
17,300
30,600
62,400
250
412
862
1,620
3,330
5,000
9,620
15,300
27,100
55,300
300
374
781
1,470
3,020
4,530
8,720
13,900
24,600
50,100
350
344
719
1,350
2,780
4,170
8,020
12,800
22,600
46,100
400
320
669
1,260
2,590
3,870
7,460
11,900
21,000
42,900
450
300
627
1,180
2,430
3,640
7,000
11,200
19,700
40,200
500
283
593
1,120
2,290
3,430
6,610
10,500
18,600
38,000
550
269
563
1,060
2,180
3,260
6,280
10,000
17,700
36,100
600
257
537
1,010
2,080
3,110
5,990
9,550
16,900
34,400
650
246
514
969
1,990
2,980
5,740
9,150
16,200
33,000
700
236
494
931
1,910
2,860
5,510
8,790
15,500
31,700
750
228
476
897
1,840
2,760
5,310
8,470
15,000
30,500
800
220
460
866
1,780
2,660
5,130
8,180
14,500
29,500
850
213
445
838
1,720
2,580
4,960
7,910
14,000
28,500
900
206
431
812
1,670
2,500
4,810
7,670
13,600
27,700
950
200
419
789
1,620
2,430
4,670
7,450
13,200
26,900
1,000
195
407
767
1,580
2,360
4,550
7,240
12,800
26,100
1,100
185
387
729
1,500
2,240
4,320
6,890
12,200
24,800
1,200
177
369
695
1,430
2,140
4,120
6,570
11,600
23,700
1,300
169
353
666
1,370
2,050
3,940
6,290
11,100
22,700
1,400
162
340
640
1,310
1,970
3,790
6,040
10,700
21,800
1,500
156
327
616
1,270
1,900
3,650
5,820
10,300
21,000
1,600
151
316
595
1,220
1,830
3,530
5,620
10,000
20,300
1,700
146
306
576
1,180
1,770
3,410
5,440
9,610
19,600
1,800
142
296
558
1,150
1,720
3,310
5,270
9,320
19,000
1,900
138
288
542
1,110
1,670
3,210
5,120
9,050
18,400
2,000
134
280
527
1,080
1,620
3,120
4,980
8,800
18,000
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m'/h, 1 degree = 0.01745 rad.
Note: All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.25
APPENDIX C
TABLE C402.4(5)
SCHEDULE 40 METALLIC PIPE
Gas
Natural
Inlet Pressure
5.0 psi
Pressure Drop
3.5 psi
Specific Gravity
0.60
PIPE SIZE (inch)
Nominal
'/2
\
1
1V4
l'/2
2
2'/2
3
4
Actual ID
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
Length (ft)
Capacity in
Cubic Feet of Gas Per Hour
10
3,190
6,430
11,800
24,200
36,200
69,700
111,000
196,000 ^
401,000
20
2,250
4,550
8,320
17,100
25,600
49,300
78,600
139,000
283,000
30
1,840
3,720
6,790
14,000
20,900
40,300
64,200
113,000
231,000
40
1,590
3,220
5,880
12,100
18,100
34,900
55,600
98,200
200,000
50
1,430
2,880
5,260
10,800
16,200
31,200
49,700
87,900
179,000
60
1,300
2,630
4,800
9,860
14,800
28,500
45,400
80,200
164,000
70
1,200
2,430
4,450
9,130
13,700
26,400
42,000
74,300
151,000
80
1,150
2,330
4,260
8,540
1 2,800
24,700
39,300
69,500
142,000
90
1,060
2,150
3,920
8,050
12,100
23,200
37,000
65,500
134,000
100
979
1,980
3,620
7,430
11,100
21,400
34,200
60,400
123,000
125
876
1,770
3,240
6,640
9,950
19,200
30,600
54,000
110,000
150
786
1,590
2,910
5,960
8,940
17,200
27,400
48,500
98,900
175
728
1,470
2,690
5,520
8,270
15,900
25,400
44,900
91,600
200
673
1,360
2,490
5,100
7,650
14,700
23,500
41,500
84,700
250
558
1,170
2,200
4,510
6,760
13,000
20,800
36,700
74,900
300
506
1,060
1,990
4,090
6,130
11,800
18,800
33,300
67,800
350
465
973
1,830
3,760
5,640
10,900
17,300
30,600
62,400
400
433
905
1,710
3,500
5,250
10,100
16,100
28,500
58,100
450
406
849
1,600
3,290
4,920
9,480
15,100
26,700
54,500
500
384
802
1,510
3,100
4,650
8,950
14,300
25,200
51,500
550
364
762
1,440
2,950
4,420
8,500
13,600
24,000
48,900
600
348
727
1,370
2,810
4,210
8,110
12,900
22,900
46,600
650
333
696
1,310
2,690
4,030
7,770
12,400
21,900
44,600
700
320
669
1,260
2,590
3,880
7,460
11,900
21,000
42,900
750
308
644
1,210
2,490
3,730
7,190
11,500
20,300
41,300
800
298
622
1,170
2,410
3,610
6,940
11,100
19,600
39,900
850
288
602
1,130
2,330
3,490
6,720
10,700
18,900
38,600
900
279
584
1,100
2,260
3,380
6,520
10,400
18,400
37,400
950
271
567
1,070
2,190
3,290
6,330
10,100
17,800
36,400
1,000
264
551
1,040
2,130
3,200
6,150
9,810
17,300
35,400
1,100
250
524
987
2,030
3,030
5,840
9,320
16,500
33,600
1,200
239
500
941
1,930
2,900
5,580
8,890
15,700
32,000
1,300
229
478
901
1,850
2,770
5,340
8,510
15,000
30,700
1,400
220
460
866
1,780
2,660
5,130
8,180
14,500
29,500
1,500
212
443
834
1,710
2,570
4,940
7,880
13,900
28,400
1,600
205
428
806
1,650
2,480
4,770
7,610
13,400
27,400
1,700
198
414
780
1,600
2,400
4,620
7,360
13,000
26,500
1,800
192
401
756
1,550
2,330
4,480
7,140
12,600
25,700
1,900
186
390
734
1,510
2,260
4,350
6,930
12,300
25,000
2,000
181
379
714
1,470
2,200
4,230
6,740
11,900
24,300
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1 -inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 mVh, 1 degree = 0.01745 rad.
Note: All table entries have been rounded to three significant digits;
117.26
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C402.4(6)
SEMIRIGID Copper tubing
Gas
Natural
Inlet Pressure
Less than 2 psi
Pressure Drop
0.3 in. w.c.
Specific Gravity
0.60
TUBE SIZE (inch)
Nominal
K&L
V4
%
'/2
%
%
1
l'/4
iV,
2
ACR
%
V2
%
%
\
iVs
1%
'
Outside
0375 ,
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
Inside
0.305
: 0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
Length (ft)
Capacity in Cubic Feet of Gas Per Hour
10
20
42
85
148
210
448
806
1,270
• 2,650
20
14
29
58
102
144
308
554
873
1,820
30
11
23
47
82
116
247
445
701
1,460
40
10
, 20
40
70
99
211
381
600
1,250
50
NA
17
35
62
88
' 187
337
532
1,110
60
NA
16
32
56
79
170
306
482
1,000
70
NA
14
29
52
73
156
281
443
924
80
NA
13
27
48
68
145
262
413
859
90
NA
13
26
45
64
136
245
387
806
100
NA
12
24 .
43
60
129
232
366
761
125
NA
11
22
38
53
114
206
324
675
150
NA
10
20
34
48
103
186
294
612
175
NA
NA
18
31
45
95
171
270
563
200
NA ■
NA
17
29
41
89
159
251
523
250
NA
NA
15
26
37
78
141
223
464
300
NA
NA
13
23
' 33
71
128
202
420
350
NA
NA
12
22
31
65
118
186
387
400
NA
NA
11
20
28
61
110
173
360
450
NA
. NA
11
19
27
57
103
162
338
500
NA
NA
10
18
25
54
97
153
319
550
NA
NA
NA
17
24
51
92
145
303
600
NA
NA
NA
16
23
49
88
139
289
650
NA
NA
NA
15
22
47
84
133
277
700
NA
. NA
■ NA
15
21
45
81
128
266
750
NA
NA
NA
14
20
43
78
123
256
800
NA
NA
NA
14
20
42
75
119
247
850
NA
NA
NA
13
19
40
73
115
239
900
NA
NA
NA
13
18
39
71
HI
232
950
NA
NA
NA
13
18
38
69
108
225
1,000
NA
NA
NA
12
17
37
67
105
219
1,100
NA
NA
NA
12
16
35
63
100
208
1,200
NA
NA
NA
11
16
34
60
95
199
1,300
NA
NA
NA
11
15
32
58
91
190
1,400
NA
NA
NA
10
14
31
56
88
183
1,500
NA
NA
NA
NA
14
30
54
84
176
1,600
NA
NA
NA'
NA
13
29
52
82
170
1,700
NA
NA
NA
NA
13
28
50
79
164
1,800
NA
NA
NA
NA
13
27
49
77
159
1,900
NA
NA
NA
NA
12
26
47
74
155
2,000
NA
NA
NA
NA
12
25
46
72
151
For SI: 1 inch = 25.4 ram, 1 foot - 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch ^vater column - 0.2488 kPa,
1 British thermal unit per hour = 0.293 1 W, 1 cubic foot per hour = 0.0283 nifh, 1 degree = 0.01745 rad.
Notes:
1. Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
2. NA means a flow of less than 10 cfh.
3. All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.27
APPENDIX C
TABLE C402.4(7)
SEMIRIGID COPPER TUBING
Gas
Natural
Inlet Pressure
Less than 2 psi
Pressure Drop
0.5 in. w.c.
Specific Gravity
0.60
TUBE SIZE (inch)
Nominal
K&L
V4
%
Vz
%
%
1
l'/4
I'A
2
ACR
'/8
V2
%
%
\
iVs
iVs
Outside
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2^125
Inside
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1:959
Length (H)
Capacity in Cubic Feet of Gas Per Hour
10
27
55
111
195
276
590
1,060
1,680
3,490
20
18
38
77
134
190
406
730
1,150
2,400
30
15
30
61
107
152
326
586
925
1,930
40
13
26
53
92
131
279
' 502
791
1,650
50
11
23
47
82
116
247
445
701
1,460
60
10
21
42
74
105
224
403
635
1,320
70
NA
19
39
68
96
206
371
585
1,220
80
NA
18
36
, 63
90
192
345
544
1;130
90
NA
17
34
59
84
180
324
510
1,060
100
NA
16
32
56
79
170
306
482
1,000
125
NA
14
28
50
70
151
271
427
890
150
NA
13
26
45
64
136
245
387
806
175
NA
12
24
41
59
125
226
356
742
200
NA
11
22
39
55
117
210
331
690
250
NA
NA
20
34
48
103
186
294
612
300
NA
NA
18
31
44
94
169
266
554
350
NA
NA
16
28
40
86
155
245
510
400
NA
NA
15
26
38
80
144
228
474
450
NA
NA
14
25
35
75
135
214
445
500
NA
NA
13
23
33
71
128
202
420
550
NA
NA
13
22
32
68
122
192
399
600
NA
NA
12
21
30
64
116
183
381
650
NA
NA
12
20
29
62
111
175
365
700
NA
NA
11
20
28
59
107
168
350
750
NA
NA
11
19
27
57
103
162
338
800
NA
NA
10
18
26
55
99
156
326
850
NA
NA
10
18
25
53
96
151
315
900
NA
NA
NA
17
24
52
93
147
306
950
NA
NA
NA
17
24
50
90
143
297
1,000
NA
NA
NA
16
23
49
88
139
289
1,100
NA
NA
NA
15
22
46
84
132
274
1,200
NA
NA
NA
15
21
44
80
126
262
1,300
NA
NA
NA
14
20
42
76
120
251
1,400
NA
NA
NA
13
19
41
73
116
241
1,500
NA
NA
NA
13
18
39
71
111
232
1,600
NA
NA
NA
13
18
38
68
108
224
1,700
NA
NA
NA
12
17
37
66
104
217
1,800
NA
NA
NA
12
17
36
64
101
210
1,900
NA
NA
NA
11
16
35
62
98
204
2,000
NA
NA
NA
11
16
34
60
95
199
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch - 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 mVh, 1 degree = 0.01745 rad.
Notes:
1. Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
2. NA means a flow of less than 10 cfh.
3. All table entries have been rounded to three significant digits.
117.28
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
Gas
Natural
TABLE C402.4(8)
SEMIRIGID COPPER TUBING
inlet Pressure
Less than 2 psi
Pressure Drop
1.0 in. w.c.
Specific Gravity
0.60
TUBE SIZE (inch)
Nominal
K&L
'/4
^/8
'/2
%
%
1
l'/4
I'll
2
ACR
%
'/2
%
'U
Vs
I'/s
1%
—
—
Outside
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
Inside
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
Length (ft)
Capacity in Cubic Feet of Gas Per Hour
10
39
80
162
283
402
859
1,550
2,440
5,080
20
27
55
111
195
276
590
1,060
1,680
3,490
30
21
44
89
156
222
474
853
1,350
2,800
40
18
38
77
134
190
406
730
1,150
2,400
50
16
33
68
119
168
359
647
1,020
2,130
60
15
30
61
107
152
326
586
925
1,930
70
13
28
57
99
140
300
539
851
1,770
80
13
26
53
92
131
279
502
791
1,650
90
12
24
49
86
122
262
471
742
1,550
100
11
23
47
82
116
247
445
701
1,460
125
NA
20
41
72
103
219
394
622
1,290
150
NA
18
37
65
93
198
357
563
1,170
175
NA
17
34
60
85
183
329
518
1,080
200
NA
16
32
56
79
170
306
482
1,000
250
NA
14
28
50
70
151
271
427
890
300
NA
13
26
45
64
136
245
387
806
350
NA
12
24
41
59
125
226
356
742
400
NA
11
22
39
55
117
210
331
690
450
NA
10
21
36
51
110
197
311
647
500
NA
NA
20
34
48
103
186
294
612
550
NA
NA
19
32
46
98
177
279
581
600
NA
NA
18
31
44
94
169
266
554
650
NA
NA
17
30
42
90
162
255
531
700
NA
NA
16
28
40
86
155
245
510
750
NA
NA
16
27
39
83
150
236
491
800
NA
NA
15
26
38
80
144
228
474
850
NA
NA
15
26
36
78
140
220
459
900
NA
NA
14
25
35
75
135
214
445
950
NA
NA
14
24
34
73
132
207
432
1,000
NA
NA
13
23
33
71
128
202
420
1,100
NA
NA
13
22
32
68
122
192
399
1,200
NA
NA
12
21
30
64
116
183
381
1,300
NA
NA
12
20
29
62
111
175
365
1,400
NA
NA
11
20
28
59
107
168
350
1,500
NA
NA
11
19
27
57
103
162
338
1,600
NA
NA
10
18
26
55
99
156
326
1,700
NA
NA
10
18
25
53
96
151
315
1,800
NA
NA
NA
17
24
52
93
147
306
1,900
NA
NA
NA
17
24
50
90
143
297
2,000
NA
NA
NA
16
23
49
88
139
289
For SL 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch - 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m'/h, 1 degree = 0.01745 rad.
Notes:
1. Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
2. NA means a flow of less than 10 cfh.
3. All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.29
APPENDIX C
TABLE C402.4(9)
SEMIRIGID COPPER TUBING
Gas
Natural
Inlet Pressure
Less than 2.0 psi
Pressure Drop
17.0in w.c.
Specific Gravity
0.60
TUBE SIZE (inch)
Nominal
K&L
V4
\
'/2
^/8
■%
1
1V4
l'/2
2
ACR
\
V2
%
%
Vs
iVs
1^8
Outside
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
Inside
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
Length (ft)
Capacity in Cubic Feet of Gas Per IHour
10
190
391
796
1,390
1,970
4,220
7,590
12,000
24,900
20
130
269
547
956
1,360
2,900
5,220
8,230
17,100
30
105
216
439
768
1,090
2,330
4,190
6,610
13,800
40
90
185
376
657
932
1,990
3,590
5,650
11,800
50
79
164
333
582
826
1,770
3,180
5,010
10,400
60
72
148
302
528
749
1,600
2,880
4,540
9,460
70
66
137
278
486
689
1,470
2,650
4,180
8,700
80
62
127
258
452
641
1,370
2,460
3,890
8,090
90
58
119
243
424
601
1,280
2,310
3,650
7,590
100
55
113
229
400
568
1,210
2,180
3,440
7,170
125
48
100
203
355
503
1,080
1,940
3,050
6,360
150
44
90
184
321
456
974
1,750
2,770
5,760
175
40
83
169
296
420
896
1,610
2,540
5,300
200
38
77
157
275
390
834
1,500
2,370
4,930 -
250
33
69
140
244
346
739
1,330
2,100
4,370
300
30
62
126
221
313
670
1,210
1,900
3,960
350
28
57
116
203
288
616
1,110
1,750
3,640
400
26
53
108
189
268
573
1,030
1,630
3,390
450
24
50
102
177
252
538
968
1,530
3,180
500
23
47
96
168
238
508
914
1,440
3,000
550
22
45
91
159
226
482
868
1,370
2,850
600
21
43
87
152
215
460
829
1,310
2,720
650
20
41
83
145
206
441
793
1,250
2,610
700
19
39
80
140
198
423
762
1,200
2,500
750
18
38
77
135
191
408
734
1,160
2,410
800
18
37
74
130
184
394
709
1,120
2,330
850
17
35
72
126
178
381
686
1,080
2,250
900
17
34
70
122
173
370
665
1,050
2,180
950
16
33
68
118
168
359
646
1,020
2,120
1,000
16
32
66
115
163
349
628
991
2,060
1,100
15
31
63
109
155
332
597
941
1,960
1,200
14
29
60
104
148
316
569
898
1,870
1,300
14
28
57
100
142
303
545
860
1,790
1,400
13
27
55
96
136
291
524
826
1,720
1,500
13
26
53
93
131
280
505
796
1,660
1,600
12
25
51
89
127
271
487
768
1,600
1,700
12
24
49
86
123
262
472
744
1,550
1,800
11
24
48
84
119
254
457
721
1,500
1,900
11
23
47
81
115
247
444
700
1,460
2,000
11
22
45
79
112
240
432
681
1,420
For SI: 1 inch - 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column - 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m'/h, 1 degree = 0.01745 rad.
Notes:
1. Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
2. All table entries have been rounded to three significant digits.
117.30
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C402.4(10)
SEMIRIGID COPPER TUBING
Gas
Natural
Inlet Pressure
2.0 psi
Pressure Drop
1.0 psi
Specific Gravity
0.60
TUBE SIZE (inch)
Nominal
K&L
'/4
^/8
'/2
=/8
'u
1
l'/4
V/2
2
ACR
Vs
'/2
'/8
'U
\
iVs
1%
Outside
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
Inside
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
Length (ft)
Capacity in Cubic Feet of Gas Per Hour
10
245
506
1,030
1,800
2,550
5,450
9,820
15,500
32,200
20
169
348
708
1,240
1,760
3,750
6,750
10,600
22,200
30
135
279
568
993
1,410
3,010
5,420
8,550
17,800
40
116
239
486
850
1,210
2,580
4,640
7,310
15,200
50
103
212
431
754
1,070
2,280
4,110
6,480
13,500
60
93
192
391
683
969
2,070
3,730
5,870
12,200
70
86
177
359
628
891
1,900
3,430
5,400
11,300
80
80
164
334
584
829
1,770
3,190
5,030
10,500
90
75
154
314
548
778
1,660
2,990
4,720
9,820
100
71
146
296
518
735
1,570
2,830
4,450
9,280
125
63
129
263
459
651
1,390
2,500
3,950
8,220
150
57
117
238
416
590
1,260
2,270
3,580
7,450
175
52
108
219
383
543
1,160
2,090
3,290
6,850
200
49
100
204
356
505
1,080
1,940
3,060
6,380
250
43
89
181
315
448
956
1,720
2,710
5,650
300
39 .
80
164
286
406
866
1,560
2,460
5,120
350
36
74
150
263
373
797
1,430
2,260
4,710
400
33
69
140
245
347
741
1,330
2,100
4,380
450
31
65
131
230
326
696
1,250
1,970
4,110
500
30
61
124
217
308
657
1,180
1,870
3,880
550
28
58
118
206
292
624
1,120
1,770
3,690
600
27
55
112
196
279 •
595
1,070
1,690
3,520
650
26
53
108
188
267
570
1,030
1,620
3,370
700
25
51
103
181
256
548
986
1,550
3,240
750
24
49
100
174
247
528
950
1,500
3,120
800
23
47
96
168
239
510
917
1,450
3,010
850
22
46
93
163
231
493
888
1,400
. 2,920
900
22
44
90
158
224
478
861
1,360
2,830
950
21
43
88
153
217
464
836
1,320
2,740
1,000
20
42
85
149
211
452
813
1,280
2,670
1,100
19
40
81
142
201
429
772
1,220
2,540
1,200
18
38
77
135
192
409
737
1,160
2,420
1,300
18
36
74
129
183
392
705
1,110
2,320
1,400
17
35
71
124
176
376
678
1,070
2,230
1,500
16
34
68
120
170
363
653
1,030
2,140
1,600
16
33
66
116
164
350
630
994
2,070
1,700
15
31
64
112
159
339
610
962
2,000
1,800
15
30
62
108
154
329
592
933
1,940
1,900
14
30
60
105
149
319
575
906
1,890
2,000
14
29
59
102
145
310
559
881
1,830
For SI:
Notes:
1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m'/h, 1 degree = 0.01745 rad.
1 . Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
2. All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.31
APPENDIX C
Gas
Natural
TABLE C402.4(11)
SEMIRIGID COPPER TUBING
Inlet Pressure
2.0 psi
Pressure Drop
1.5 psi
Specific Gravity
0.60
SPECIAL
USE
Pipe sizing between point of delivery and the house line regulator. Total load supplied by a single house line regulator not exceeding 150
cubic feet per hour.
TUBE SIZE (inch)
Nominal
K&L
'/4
%
'/2
^/8
'u
1
l'/4
IV2
2
ACR
%
'/2
^/8
V4
\
I'/s
1%
Outside
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
Inside
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
Length (ft)
Capacity in Cubic Feet of Gas Per Hour
10
303
625
1,270
2.220
3,150
6,740
12,100
19,100
39,800
20
208
430
874
1,530
2,170
4,630
8,330
13,100
27,400
30
167
345
702
1,230
1,740
3,720
6,690
10,600
22,000
40
143
295
601
1,050
1,490
3,180
5,730
9,030
18,800
50
127
262
532
931
1,320
2,820
5,080
8,000
16,700
60
115
237
482
843
1,200
2,560
4,600
7,250
15,100
70
106
218
444
776
1,100
2,350
4,230
6,670
13,900
80
98
203
413
722
1,020
2,190
3,940
6,210
12,900
90
92
190
387
677
961
2,050
3,690
5,820
12,100
100
87
180
366
640
907
1,940
3,490
5,500
1 1,500
125
77
159
324
567
804
1,720
3,090
4,880
10,200
150
70
144
294
514
729
1,560
2,800
4,420
9,200
175
64
133
270
472
670
1,430
. 2,580
4,060
8,460
200
60
124
252
440
624
1,330
2,400
3,780
7,870
250
53
110
223
390
553
1,180
2,130
3,350
6,980
300
48
99
202
353
501
1,070
1,930
3,040
6,320
350
44
91
186
325
461
984
1,770
2,790
- 5,820
400
41
85
173
302
429
916
1,650
2,600
5,410
450
39
80
162
283
402
859
1,550
2,440
5,080
500
36
75
153
268
380
811
1,460
2,300
4,800
550
35
72
146
254
361
771
1,390
2,190
4,560
600
33
68
139
243
344
735
1,320
2,090
4,350
650
32
65
133
232
330
704
1,270
2,000
4,160
700
30
63
128
223
317
676
1,220
1,920
4,000
750
29
60
123
215
305
652
1,170
1,850
3,850
800
28
58
119
208
295
629
1,130
1,790
3,720
850
27
57
115
201
285
609
1,100
1,730
3,600
900
27
55
111
195
276
590
1,060
1,680
3,490
950
26
53
108
189
268
573
1,030
1,630
3,390
1,000
25
52
105
184
261.
558
1,000
1,580
3,300
1,100
24
49
100
175
248
530
954
1,500
3,130
1,200
23
47
95
167
237
505
910
1,430
2,990
1,300
22
45
91
160
227
484
871
1,370
2,860
1,400
21
43
88
153
218
465
837
1,320
2,750
1,500
20
42
85
148
210
448
806
1,270
2,650
1,600
19
40
82
143
202
432
779
1,230
2,560
1,700
19
39
79
138
196
419
753
1,190
2,470
1,800
18
38
77
134
190
406
731
1,150
2,400
1,900
18
37
74
130
184
394
709
1,120
2,330
2,000
17
36
72
126
179
383
690
1,090
2,270
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.293 1 W, 1 cubic foot per hour = 0.0283 ni/h, 1 degree = 0.01745 rad.
Notes:
1 . Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
2. Where this table is used to size the tubing upstream of a line pressure regulator, the pipe or tubing downstream of the line pressure regulator shall be sized using a pressure drop not greater
than 1 inch w.c.
3. All table entries have been rounded to three significant digits.
117.32
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
Gas
Natural
TABLE C402.4(12)
SEMIRIGID COPPER TUBING
Inlet Pressure
5.0 psi
Pressure Drop
3.5 psi
Specific Gravity
0.60
TUBE SIZE (inch)
Nominal
K&L
V4
%
'/2
%
%
1
IV4
I'll
2
ACR
'h
^ V2
%
'U
'k
iVs
1^/8
Outside
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
Inside
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
Length (ft)
Capacity in Cubic Feet of Gas Per Hour
10
511
1,050
2,140
3,750
5,320
11,400
20,400
32,200
67,100
20
351
724
1,470
2,580
3,650
7,800
14,000
22,200
46,100
30
282
582
1,180
2,070
2,930
6,270
11,300
17,800
37,000
40
241
498
1,010
1,770
2,510
5,360
9,660
15,200
31,700
50
214
441
898
1,570
2,230
4,750
8,560
13,500
28,100
60
194
400
813
1,420
2,020
4,310
7,750
12,200
25,500
70
178
368
748
1,310
1,860
3,960
7,130
11,200
23,400
80
166
342
696
1,220
1,730
3,690
6,640
10,500
21,800
90
156
321
653
1,140
1,620
3,460
6,230
9,820
20,400
100
147
303
617
1,080
1,530
3,270
5,880
9,270
19,300
125
130
269
547
955
1,360
2,900
5,210
8,220
17,100
150
118
243
495
866
1,230
2,620
4,720
7,450
15,500
175
109
224
456
796
1,130
2,410
4,350
6,850
14,300
200
101
208
424
741
1,050
2,250
4,040
6,370
13,300
250
90
185
376
657
932
1,990
3,580
5,650
11,800
300
81
167
340
595
844
1,800
3,250
5,120
10,700
350
75
154
313
547
777
1,660
2,990
4,710
9,810
400
69
143
291
509
722
1,540
2,780
4,380
9,120
450
65
134
273
478
678
1,450
2,610
4,110
8,560
500
62
127
258
451
640
1,370
2,460
3,880
8,090
550
58
121
245
429
608
1,300
2,340
3,690
7,680
600
56
115
234
409
580
1,240
2,230
3,520
7,330
650
53
110
224
392
556
1,190
2,140
3,370
7,020
700
51
106
215
376
534
1,140
2,050
3,240
6,740
750
49
102
207
362
514
1,100
1,980
3,120
6,490
800
48
98
200
350
497
1,060
1,910
3,010
6,270
850
46
95
194
339
481
1,030
1,850
2,910
6,070
900
45
92
188
328
466
1,000
1,790
2,820
5,880
950
L 43
90
182
319
452
967
1,740
2,740
5,710
1,000
42
87
177
310
440
940
1,690
2,670
5,560
1,100
40
83
169
295
418
893
1,610
2,530
5,280
1,200
38
79
161
281
399
852
1,530
2,420
5,040
1,300
37
76
154
269
382
816
1,470
2,320
4,820
1,400
35
73
148
259
367
784
1,410
2,220
4,630
1,500
34
70
143
249
353
755
1,360
2,140
4,460
1,600
33
68
138
241
341
729
1,310
2,070
4,310
1,700
32
65
133
233
330
705
1,270
2,000
4,170
1,800
31
63
129
226
320
684
1,230
1,940
4,040
1,900
30
62
125
219
311
664
1,200
1,890
3,930
2,000
29
60
122
213
302
646
1,160
1,830
3,820
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour - 0.0283 ralh, 1 degree = 0.01745 rad.
Notes:
1. Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
2. All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.33
APPENDIX C
Gas r
"Jatural
TABLEC402.4(13)
CORRUGATED STAINLESS STEEL TUBING (CSST)
Inlet Pressure I
.ess than 2 psi
Pressure Drop 0.5 in. w.c.
Specific Gravity 0.60
TUBE SIZE (EHD)
Flow
Designation
13
15
18
19
23
25
30
31
37
46
48
60
62
Length (ft)
Capacity in Cubic Feet of Gas Per Hour
5
46
63
115
134
225
270
471
546
895
1,790
2,070
3,660
4,140
10
32
44
82
95
161
192
330
383
639
1,260
1,470
2,600
2,930
15
25
35
66
77
132
157
267
310
524
1,030
1,200
2,140
2,400
20
22
31
58
67
116
137
231
269
456
888
1,050
1,850
2,080
25
19
27
52
60
104
122
206
240
409
793
936
1,660
1,860
30
18
25
47
55
96
112
188
218
374
723
856
1,520
1,700
40
15
21
41
47
83
97
162
188
325
625
742
1,320
1,470
50
13
19
37
42
75
87
144
168
292
559
665
1,180
1,320
60
12
17
34
38
68
80
131
153
267
509
608
1,080
1,200
70
11
16
31
36
63
74
121
141
248
471
563
1,000
1,110
80
10
15
^29
33
60
69
113
132
232
440
527
940
1,040
90
10
14
28
32
57
65
107
125
219
415
498
887
983
100
9
13
26
30
54
62
101
.118
208
393
472
843
933
150
7
10
20
23
42
48
78
91
171
320
387
691
762
200
6
9
18
21
38
44
71
82
148
277
336
600
661
250
5
8
16
19
34
39
63
74
133
247
301
538
591
300
5
7
15
17
32
36
57
67
95
226
275
492
540
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895]<:Pa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m^/h, 1 degree = 0.01745 rad.
Notes:
1 . Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent
length of tubing to the following equation: L - 1.3n, where L is additional length (feet) of tubing and« is the number of additional fittings and/or bends.
2. EHD — Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the
greater the gas capacity of the tubing.
3. All table entries have been rounded to three significant digits.
117.34
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
Gas Natural
TABLE 6402.4(14)
CORRUGATED STAINLESS STEEL TUBING (CSST)
Inlet Pressure Less than 2 psi
Pressure Drop 3.0 in. w.c.
.
Specific Gravity 0.60
TUBE SIZE (EHD)
Flow
Designation
13
15
18
19
23
25
30
31
37
46
48 60
62
Length (ft)
Capacity in Cubic Feet of Gas Per Hour
5
120
160
277
327
529
649
1,180
1,370
2,140
4,430
5,010
8,800
10,100
10
83
112
197
231
380
462
828
958
1,530
3,200
3,560
6,270
7,160
15
67
90
161
189
313
379
673
778
1,250
2,540
2,910
5,140
5,850
20
57
78
140
164
273
329
580
672
1,090
2,200
2,530
4,460
5,070
25
51
69
125
147
245
295
518
599
978
1,960
2,270
4,000
4,540
30
46
63
115
134
225 ,
270
471
546
895
1,790
2,070
3,660
4,140
40
39
54
100
116
196
234
407
471
778
1,550
1,800
3,180
3,590
50
35
48
89
104
176
210
363
421
698
1,380
1,610
2,850
3,210
60
32
44
82
95
161
192
330
383
639
1,260
1,470
2,600
2,930
70
29
41
76
88
150
178
306
355
593
1,170
1,360
2,420
2,720
80
27
38
71
82
141
167
285
331
555
1,090
1,280
2,260
2,540
90
26
36
67
77
133
157
268
311
524
1,030
1,200
2,140
2,400
100
24
34
63
73
126
149
254
295
498
974
1,140
2,030
2,280
150
19
27
52
60
104
122
206
240
409
793
936
1,660
1,860
200
17
23
45
52
91
106
178
207 ^
355 ^
686
812
1,440
1,610
250
15
21
40
46
82
95
159
184
319
613
728
1,290
1,440
300
13
19
37
42
75
87
144
168
234
559
665
1,180
1,320
For SI: 1 inch - 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m%, 1 degree = 0.01745 rad.
Notes:
1 . Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent
length of tubing to the following equation: L = 1 .3n where L is additional length (feet) of tubing and n is the number of additional fittings and/or bends.
2. EHD — Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the
greater the gas capacity of the tubing.
3. All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.35
APPENDIX C
Gas 1
Natural
TABLEC402.4(15)
CORRUGATED STAINLESS STEEL TUBING (CSST)
Inlet Pressure L
.ess than 2 psi
Pressure Drop (
3.0 in. w.c.
Specific Gravity 0.60
TUBE SIZE (EHD)
Flow
Designation
13
15
18
19
23
25
30
31
37
46
48
60
62
Length (ft)
Capacity In Cubic Feet of Gas Per Hour
5
173
229
389
461
737
911
1,690
1,950
3,000
6,280
7,050
12,400
14,260
10
120
160
277
327
529
649
1,180
1,370
2,140
4,430
5,010
8,800
10,100
15
96
130
227
267
436
532
960
1,110
1,760
3,610
4,100
7,210
8,260
20
83
112
197
231
380
462
828
958
1,530
3,120
3,560
6,270
7,160
25
74
99
176
207
342
414
739
855
1,370
2,790
3,190
5,620
6,400
30
67
90
161
189
313
379
673
778
1,250
2,540
2,910
5,140
5,850
40
57
78
140
164
273
329
580
672
1,090 J
2,200
2,530
4,460
5,070
50
51
69
125
147
245
295
518
599
978
1,960
2,270
4,000
4,540
60
46
63
115
134
225
270
471
546
895
1,790
2,070
3,660
4,140
70
42
58
106
124
209
250
435
505
830
1,660
1,920
3,390
3,840
80
39
54
100
116
196
234
407
471
778
1,550
1,800
3,180
3,590
90
37
51
94
109-
185
221
383
444
735
1,460
1,700
3,000
3,390
100
35
48
89
104
176
210
363
421
698
1,380
1,610
2,850
3,210
150
28
39
73
85
145
172
294
342
573
1,130
1,320
2,340
2,630
200
24
34
63
73
126
149
254
295
498
974
1,140
2,030
2,280
250
21
30
57
66
114
134
226
263
447
870
1,020
1,820
2,040
300
19
27
52
60
104
122
206
240
409
793
936
1,660
1,860
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m^/h, 1 degree = 0.01745 rad.
Notes:
1 . Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent
length of tubing to the following equation: L = 1.3n where L is additional length (feet) of tubing and n is the number of additional fittings and/or bends.
2. EHD — Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the
greater the gas capacity of the tubing.
3. All table entries have been rounded to three significant digits.
117.36
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
Gas r
Natural
TABLEC402.4(16)
CORRUGATED STAINLESS STEEL TUBING (CSST)
Inlet Pressure 'c
?.0 psi
Pressure Drop 1
.Opsi
Specific Gravity (
).60
TUBE SIZE (EHD)
Flow
Designation
13
15
18
19
23
25
30
31
37
46
48
60
62
Length (ft)
Capacity In Cubic Feet of Gas Per Hour
10
270
353
587
700
1,100
1,370
2,590
2,990
4,510
9,600
10,700
18,600
21,600
25
166
220
374
444
709
876
1,620
1,870
2,890
6,040
6,780
11,900
13,700
30
151
200
342
405
650
801
1,480
1,700
2,640
5,510
6,200
10,900
12,500
40
129
172
297
351
567
696
1,270
1,470
2,300
4,760
5,380
9,440
10,900
50
115
154
266
314
510
624
1,140
1,310
2,060
4,260
4,820
8,470
9,720
75
93
124
218
257
420
512
922
1,070
1,690
3,470
3,950
6,940
7,940
80
89
120
211
249
407
496
892
1,030
1,640
3,360
3,820
6,730
7,690
100
79
107
189
222
366
445
795
920
1,470
3,000
3,420
6,030
6,880
150
64
87
155
182
302
364
646
748
1,210
2,440
2,800
4,940
5,620
200
55
75
135
157
263
317
557
645
1,050
2,110
2,430
4,290
4,870
250
49
67
121
141
236
284
497
576
941
1,890
2,180
3,850
4,360
300
44
61
110
129
217
260
453
525
862
1,720
1,990
3,520
3,980
400
38
52
96
111
189
225
390
453
749
1,490
1,730
3,060
3,450
500
34
46
86
100
170
202
348
404
552
1,330
1,550
2,740
3,090
For SI: 1 inch = 25.4 mm, 1 foot = 304.8' mm, 1 pound per square inch = 6.895kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m%, 1 degree = 0.01745 rad.
Notes:
1 . Table does not include effect of pressure drop across the line regulator. Where regulator loss exceeds ^1^^ psi, DO NOT USE THIS TABLE. Consult with the regula-
tor manufacturer for pressure drops and capacity factors. Pressure drops across a regulator may vary with flow rate.
2. CAUTION: Capacities shown in the table might exceed maximum capacity for a selected regulator. Consult with the regulator or tubing manufacturer for guid-
ance.
3. Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent
length of tubing to the following equation: L = l.Bn where L is additional length (feet) of tubing and « is the number of additional fittings and/or bends.
4. EHD — Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the
greater the gas capacity of the tubing.
5. All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.37
APPENDIX C
Gas
^Jatural
TABLE C402.4(17)
CORRUGATED STAINLESS STEEL TUBING (CSST)
Inlet Pressure J
5.0 psi
Pressure Drop C
}.5 psi
Specific Gravity (
).60
TUBE SIZE (EHD)
Flow
Designation
13
15
18
19
23
25
30 31
37
46
48
60
62
Length (ft)
Capacity in Cubic Feet of Gas Per Hour
10
523
674
1,080
1,300
2,000
2,530
4,920
5,660
8,300
18,100
19,800
34,400
40,400
25
322
420
691
827
1,290
1,620
3,080
3,540
5,310
11,400
12,600
22,000
25,600
30
292
382
632
755
1,180
1,480
2,800
3,230
4,860
10,400
11,500
20,100
23,400
40
251
329
549
654
1,030
1,280
2,420
2,790
4,230
8,970
10,000
17,400
20,200
50
223
293
492
586
926
1,150
2,160
2,490
3,790
8,020
8,930
15,600
18,100
75
180
238
403
479
763
944
1,750
2,020
3,110
6,530
7,320
12,800
14,800
80
174
230
391
463
740
915
1,690
1,960
3,020
6,320
7,090
12,400
14,300
100
154
205
350
415
665
820
1,510
1,740
2,710
5,650
6,350
11,100
12,800
150
124
166
•287
339
548
672
1,230
1,420
2,220
4,600
5,200
9,130
10,500
200
107
143
249
294
478
584
1,060
1,220
1,930
3,980
4,510
7,930
9,090
250
95
128
223
263
430
524
945
1,090
1,730
3,550
4,040
7,110
8,140
300
86
116
204
240
394
479
860
995
1,590
3,240
3,690
6,500
7,430
400
74
100
177
208
343
416
742
858
1,380
2,800
3,210
5,650
6,440
500
66
89
159
186
309
373
662
766
1,040
2,500
2,870
5,060
5,760
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m'/h, 1 degree = 0.01745 rad.
Notes:
1 . Table does not include effect of pressure drop across the hne regulator. Where regulator loss exceeds ^1^ psi, DO NOT USE THIS TABLE. Consult with the regula-
tor manufacturer for pressure drops and capacity factors. Pressure drops across a regulator may vary with flow rate.
2. CAUTION: Capacities shown in the table might exceed maximum capacity for a selected regulator. Consult with the regulator or tubing manufacturer for guid-
ance.
3. Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent
length of tubing to the following equation: L = 1 .3n where L is additional length (feet) of tubing and n is the number of additional fittings and/or bends.
4. EHD — Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the
greater the gas capacity of the tubing.
5. All table entries have been rounded to three significant digits.
117.38
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLEC402.4(18)
POLYETHYLENE PLASTIC PIPE
Gas
Natural
Inlet Pressure
Less than 2
psi
Pressure Drop
0.3 in. w.c.
Specific Gravity
0.60
PIPE SIZE (in.)
Nominal OD
'l2
'U
1
1%
1%
2 ■
Designation
SDR 9.33
SDR 11.0
SDR 11.00
SDR 10.00
SDR 11.00
SDR 11.00
Actual ID
0.660
0.860
1.077
1.328
1.554
1.943
Length (ft)
Capacity in Cubic Feet of Gas per Hour
10
153
305
551
955
1,440
2,590
20
105
210
379
656
991
1,780
30
84
169
304
527
796
1,430
40
72
144
260
451
681
1,220
50
64
128
231
400
604
1,080
60
58
116
209
362
547
983
70
53
107
192
333
503
904
80
50
99
179
310
468
841
90
46
93
168
291
439
789
100
44
88
159
275
415
745
125
39
78
141
243
368
661
150
35
71
127
221
333
598
175
32
65
117
203
306
551
200
30
60
109
189
285
512
250
27
54
97
167
253
454
300
24
48
88
152
229
411
350
22
45
81
139
211
378
400
21
42
75
130
196
352
450
19
39
70
122
184
330
500
18
37
66
115
174
312
For SI: 1 inch = 25.4 mm, 1 foot = 304.8
1 British thermal unit per hour =
Note: All table entries have been rounded
I mm, 1 pound per square inch = 6.895kPa, 1-inch water column = 0.2488
0.2931 W, 1 cubic foot per hour = 0.0283 m%, 1 degree = 0.01745 rad.
to three significant digits.
kPa,
2007 OREGON MECHANICAL SPECIALTY CODE
117.39
APPENDIX C
TABLE C402.4(19)
POLYETHYLENE PLASTIC PIPE
Gas
Natural
Inlet Pressure
Less than 2
psi
Pressure Drop
0.5 in. w.c.
Specific Gravity
0.60
PIPE SIZE (in.)
Nominal OD
V,
'U
1
IV4
iv.
2
Designation
SDR 9.33
SDR 11.0
SDR 11.00
SDR 10.00
SDR 11.00
SDR 11.00
Actual ID
0.660
0.860
1.077
1.328
1.554
1.943
Length (ft)
Capacity in Cubic Feet of Gas per Hour
10
201
403
726
1,260
1,900
3,410
20
138
277
499
865
1,310
2,350
30
111
222
401
695
1,050
1,880
40
95
190
343
594
898
1,610
50
84
169
304
527
796
1,430
60
76
153
276
477
721
1,300
70
70
140
254
439
663
1,190
80
65
131
236
409
617
1,110
90
61
123
221
383
579
1,040
100
58
116
209
362
547
983
125
51
103
185
321
485
871
150
46
93
168
291
439
789
175
43
86
154
268
404
726
200
40
80
144
249
376
675
250
35
71
127
221
333
598
300
32
64
115
200
302
542
350
29
59
106
184
278
499
400
27
55
99
171
258
464
450
26
51
93
160
242
435
500
24
48
88
152
229
411
For SI: 1 inch = 25.4 mm, 1 foot = 304.J
1 British thermal unit per hour =
Note: All table entries have been rounded
1 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488
0.2931 W, 1 cubic foot per hour = 0.0283 m'lh, 1 degree = 0.01745 rad.
to three significant digits.
kPa,
117.40
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C402.4(20)
POLYETHYLENE PLASTIC PIPE
Gas
Natural
Inlet Pressure
2.0 psi
Pressure Drop
1 .0 psi
Specific Gravity
0.60
PIPE SIZE (in.)
Nominal OD
•/,
\
1
iV.
iV,
2
Designation
SDR 9.33
SDR 11.0
SDR 11.00
SDR 10.00
SDR 11.00
SDR 11.00
Actual ID
0.660
0.860
1.077
1.328
1.554
1.943
Length (ft)
Capacity in Cubic Feet of Gas per Hour
10
1,860
3,720
6,710
11,600
17,600
31,600
20
1,280
2,560
4,610
7,990
12,100
21,700
30
1,030
2,050
3,710
6,420
9,690
17,400
40
878
1,760
3,170
5,490
8,300
14,900
50
778
1,560
2,810
4,870
7,350
13,200
60
705
1,410
2,550
4,410
6,660
12,000
70
649
1,300
2,340
4,060
6,130
11,000
80
603
1,210
2,180
3,780
5,700
10,200
90
566
1,130
2,050
3,540
5,350
9,610
100
535
1,070
1,930
3,350
5,050
9,080
125
474
949
1,710
2,970
4,480
8,050
150
429
860
1,550
2,690
4,060
7,290
175
395
791
1,430
2,470
3,730
6,710
200
368
736
1,330
2,300
3,470
6,240
250
326
652
1,180
2,040
3,080
5,530
300
295
591
1,070
1,850
2,790
5,010
350
272
544
981
1,700
2,570
4,610
400
253
506
913
1,580
2,390
4,290
450
237
475
856
1,480
2,240
4,020
500
224
448
809
1,400
2,120
3,800
550
213
426
768
1,330
2,010
3,610
600
203
406
733
1,270
1,920
3,440
650
194
389
702
1,220
1,840
3,300
700
187
374
674
1,170
1,760
3,170
750
180
360
649
1,130
1,700
3,050
800
174
348
627
1,090
1,640
2,950
850
168
336
607
1,050
1,590
2,850
900
163
326
588
1,020
1,540
2,770
950
158
317
572
990
1,500
2,690
1,000
154
308
556
963
1,450
2,610
1,100
146
293
528
915
1,380
2,480
1,200
139
279
504
873
1,320
2,370
1,300
134
267
482
836
1,260
2,270
1,400
128
257
463
803
1,210
2,180
1,500
124
247
446
773
1,170
2,100
1,600
119
239
431
747
1,130
2,030
1,700
115
231
417
723
1,090
1,960
1,800
112
224
404
701
1,060
1,900
1,900
109
218
393
680
1,030
1,850
2,000
106
212
382
662
1,000
1,800
For SI: 1 inch = 25.4 mm, 1 foot = 304.
1 British thermal unit per hour =
Note: All table entries have been rounded to
8 mm, 1 pound per square inch = 6.895 kPa, 1-inch
= 0.293 1 W, 1 cubic foot per hour = 0.0283 mlh, 1
three significant digits.
water column = 0.2488 kPa,
degree = 0.01745 rad.
2007 OREGON MECHANICAL SPECIALTY CODE
117.41
APPENDIX C
TABLE C402.4(21)
POLYETHYLENE PLASTIC TUBING
TABLE C402.4(22)
POLYETHYLENE PLASTIC TUBING
Gas
Natural
Inlet Pressure
Less than 2.0 psi
Pressure Drop
0.3 in. w.c.
Specific Gravity
0.60
PLASTIC TUBING SIZE (CTS) (in.)
Nominal OD
v^
%
Designation
SDR 7.00
SDR 11.00
Actual ID
0.445
0.927
Length (ft)
Capacity in Cubic Feet of Gas per Hour
10
54
372
20
37
256
30
30
205
40
26
176
50
23
156
60
21
141
70
19
130
80
18
121
90
17
113
100
16
107
125
14
95
150
13
86
175
12
79
200
11
74
225
10
69
250
NA
65
275
NA
62
300
NA
59
350
NA
54
400
NA
51
450
NA
47
500
NA
45
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm,
1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
I British thermal unit per hour = 0.2931 W,
1 cubic foot per hour = 0.0283 m%, 1 degree = 0.01745 rad.
Notes:
1 . NA means a flow of less than 1 cfh.
2. All table entries have been rounded to three significant digits.
Gas
Natural
Inlet Pressure
Less than 2.0 psi
Pressure Drop
0.5 in. w.c.
Specific Gravity
0.60
PLASTIC TUBING SIZE (CTS) (in.)
Nominal OD
'/a
%
Designation
SDR 7.00
SDR 11.00
Actual ID
0.445
0.927
Length (ft)
Capacity in Cubic Feet of Gas per Hour
10
72
490
20
49
337
30
39
271
40
34
232
50
30
205
60
27
186
70
25
171
80
23
159
90
22
149
100
21
141
125
18
125
150
17
113
175
15
104
200
14
97
225
13
91
250
12
86
275
11
82
300
11
78
350
10
72
400
NA
67
450
NA
63
500
NA
59
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm,
1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W,
1 cubic foot per hour = 0.0283 m%, 1 degree = 0.01745 rad.
Notes:
1 . NA means a flow of less than 10 cfh.
2. All table entries have been rounded to three significant digits.
117.42
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
Gas
Undiluted Propane
TABLE C402.4(23)
SCHEDULE 40 METALLIC PIPE
Inlet Pressure
10.0 psi
Pressure Drop
1 .0 psi
Specific Gravity
1.50
SPECIAL USE
Pipe sizing between first stage (high-pressure regulator) and second stage (low-pressure regulator).
PIPE SIZE (in.)
Nominal
'/2
%
1 l'/4
l'/2
2
2'/2
3
4
Actual ID
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
Length (ft)
Capacity in Thousands of Btu per Hour
10
3,320
6,950
13,100
26,900
40,300
77,600
124,000
219,000
446,000
20
2,280
4,780
9,000
18,500
27,700
53,300
85,000
150,000
306,000
30
1,830
3,840 ^
7,220
14,800
22,200
42,800
68,200
121,000
246,000
40
1,570
3,280
6,180
12,700
19,000
36,600
58,400
103,000
211,000
50
1,390
2,910
5,480
11,300
16,900
32,500
51,700
91,500
187,000
60
1,260
2,640
4,970
10,200
15,300
29,400
46,900
82,900
169,000
70
1,160
2,430
4,570
9,380
14,100
27,100
43,100
76,300
156,000
80
1,080
2,260
4,250
8,730
13,100
25,200
40,100
70,900
145,000
90
1,010
2,120
3,990
8,190
12,300
23,600
37,700
66,600
136,000
100
956
2,000
3,770
7,730
11,600
22,300
35,600
62,900
128,000
125
848
1,770
3,340
6,850
10,300
19,800
31,500
55,700
1 14,000
150
768
1,610
3,020
6,210
9,300
17,900
28,600
50,500
103,000
175
706
1,480
2,780
5,710
8,560
16,500
26,300
46,500
94,700
200
657
1,370
2,590
5,320
7,960
15,300
24,400
43,200
88,100
250
582
1,220
2,290
4,710
7,060
13,600
21,700
38,300
78,100
300
528
1,100
2,080
4,270
6,400
12,300
19,600
34,700
70,800
350
486
1,020
1,910
3,930
5,880
11,300
18,100
31,900
65,100
400
452
945
1,780
3,650
5,470
10,500
16,800
29,700
60,600
450
424
886
1,670
3,430
5,140
9,890
15,800
27,900
56,800
500
400
837
1,580
3,240
4,850
9,340
14,900
26,300
53,700
550
380
795
1,500
3,070
4,610
8,870
14,100
25,000
51,000
600
363
759
1,430
2,930
4,400
8,460
13,500
23,900
48,600
650
347
726
1,370
2,810
4,210
8,110
12,900
22,800
46,600
700
334
698
1,310
2,700
4,040
7,790
12,400
21,900
44,800
750
321
672
1,270
2,600
3,900
7,500
12,000
21,100
43,100
800
310
649
1,220
2,510
3,760
7,240
11,500
20,400
41,600
850
300
628
1,180
2,430
3,640
7,010
11,200
19,800
40,300
900
291
609
1,150
2,360
3,530
6,800
10,800
19,200
39,100
950
283
592
1,110
2,290
3,430
6,600
10,500
18,600
37,900
1,000
275
575
1,080
2,230
3,330
6,420
10,200
18,100
36,900
1,100
261
546
1,030
2,110
3,170
6,100
9,720
17,200
35,000
1,200
249
521
982
2,020
3,020
5,820
9,270
16,400
33,400
1,300
239
499
940
1,930
2,890
5,570
8,880
15,700
32,000
1,400
229
480
903
1,850
2,780
5,350
8,530
15,100
30,800
1,500
221
462
870
1,790
2,680
5,160
8,220
14,500
29,600
1,600
213
446
840
1,730
2,590
4,980
7,940
14,000
28,600
1,700
206
432
813
1,670
2,500
4,820
7,680
13,600
27,700
1,800
200
419
789
1,620
2,430
4,670
7,450
13,200
26,900
1,900
194
407
766
1,570
2,360
4,540
7,230
12,800
26,100
2,000
189
395
745
1,530
2,290
4,410
7,030
12,400
25,400
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column - 0.2488 kPa,
1 British thermal unit per hour - 0.293 1 W, 1 cubic foot per hour = 0.0283 m'/h, 1 degree = 0.01745 rad.
Note: All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.43
APPENDIX C
Gas
Undiluted Propane
TABLE C402.4(24)
SCHEDULE 40 METALLIC PIPE
Inlet Pressure
10.0 psi
Pressure Drop
3.0 psi
Specific Gravity
1.50
SPECIAL USE
Pipe sizing between first stage (high-pressure regulator) and second stage (low-pressure regulator).
PIPE SIZE (In)
Nominal
'/2
%
1
l'/4
I'll
2
2V2
3
4
Actual ID
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
Length (ft)
Capacity in Thousands of Btu per Hour
10
5,890
12,300
23,200
47,600
71,300
137,000
219,000
387,000
789,000
20
4,050
8,460
15,900
32,700
49,000
94,400
150,000
266,000
543,000
30
3,250
6,790
12,800
26,300
39,400
75,800
121,000
214,000
436,000
40
2,780
5,810
11,000
22,500
33,700
64,900
103,000
183.000
373,000
50
2,460
5,150
9,710
19,900
29,900
57,500
91,600
162.000
330,000
60
2,230
4,670
8,790
18,100
27,100
52,100
83,000
147,000
299,000
70
2,050
4,300
8,090
16,600
24,900
47,900
76,400
135,000
275,000
80
1,910
4,000
7,530
15,500
23,200
44,600
71,100
126,000
256,000
90
1,790
3,750
7,060
14,500
21,700
41,800
66,700
118,000
240,000
100
1,690
3,540
6,670
13,700 '
20,500
39,500
63,000
111,000
227,000
125
1,500
3,140
5,910
12,100
18,200
35,000
55,800
98,700
201,000
150
1,360
2,840
5,360
11,000
16,500
31,700
50,600
89,400
182,000
175
1,250
2,620
4,930
10,100
15,200
29,200
46,500
82,300
167,800
200
1,160
2,430
4,580
9,410
14,100
27,200
43,300
76,500
156,100
250
1,030
2,160
4,060
8,340
12,500
24,100
38,400
67,800
138,400
300
935
1,950
3,680
7,560
11,300
21,800
34,800
61, .500
125,400
350
860
1,800
3,390
6,950
10,400
20,100
32,000
56,500
115,300
400
800
1,670
3,150
6,470
9,690
18,700
29,800
52,600
107,300
450
751
1,570
2,960
6,070
9,090
17,500
27,900
49,400
100,700
500
709
1,480
2,790
5,730
8,590
16,500
26,400
46,600
95,100
550
673
1,410
2,650
5,450
8,160
15,700
25,000
44,300
90,300
600
642
1,340
2,530
5,200
7,780
15,000
23,900
42,200
86,200
650
615
1,290
2,420
4,980
7,450
14,400
22,900
40,500
82,500
700
591
1,240
2,330
4,780
7,160
13,800
22,000
38,900
79,300
750
569
1,190
2,240
4,600
6,900
13,300
21,200
37,400
76,400
800
550
1,150
2,170
4,450
6,660
12,800
20,500
36,200
73,700
850
532
1,110
2,100
4,300
6,450
12,400
19,800
35,000
71,400
900
516
1,080
2,030
4,170
6,250
12,000
19,200
33,900
69,200
950
501
1,050
1,970
4,050
6,070
11,700
18,600
32,900
67,200
1,000
487
1,020
1,920
3,940
5,900
11,400
18,100
32,000
65,400
1,100
463
968
1,820
3,740
5,610
10,800
17,200
30,400
62,100
1,200
442
923
1,740
3,570
5,350
10,300
16,400
29,000
59,200
1,300
423
884
1,670
3,420
5,120
9,870
15,700
27,800
56,700
1,400
406
849
1,600
3,280
4,920
9,480
15,100
26,700
54,500
1,500
391
818
1,540
3,160
4,740
9,130
14,600
25,700
52,500
1,600
378
790
1,490
3,060
4,580
8,820
14,100
24,800
50,700
1,700
366
765
1,440
2,960
4,430
8,530
13,600
24,000
49,000
1,800
355
741
1,400
2,870
4,300
8,270
13,200
23,300
47,600
1,900
344
720
1,360
2,780
4,170
8,040
12,800
22,600
46,200
2,000
335
700
1,320
2,710
4,060
7,820
12,500
22,000
44,900
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 mVh, 1 degree = 0.01745 rad.
Note: All table entries have been rounded to three significant digits.
117.44
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C402.4(25)
SCHEDULE 401 METALLIC PIPE
Gas
Undiluted Propane
Inlet Pressure
2.0 psi
Pressure Drop
1.0 psi
Specific Gravity
1.50
PIPE SIZE (In.)
Nominal
'/2
'U
1
IV4
IV2
2
2'/2
3
4
Actual ID
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
Length (ft)
Capacity in Thousands of Btu per Hour
10
2,680
5,590'
10,500
21,600
32,400
62,400
99,500
176,000
359,000
20
1,840
3,850
7,240
14,900
22,300
42,900
68,400
121,000
247,000
30
1,480
3,090
5,820
11,900
17,900
. 34,500
54,900
97,100
198,000
40
1,260
2,640'
4,980
10,200
15,300
29,500
47,000
83,100
170,000
50
1,120
2,340
4,410
9,060
13,600
26,100
41,700
73,700
150,000
60
1,010
2,120
4,000
8,210
12,300
23,700
37,700
66,700
136,000
70
934
1,950
3,680
7,550
11,300
21,800
34,700
61,400
125,000
80
869
1,820
3,420
7,020
10,500
20,300
32,300
57,100
116,000
90
815
1,700
3,210
6,590
9,880
19,000
30,300
53,600
109,000
100
770
1,610
3,030
6,230
9,330
18,000
28,600
50,600
103,000
125
682
1,430'
2,690
5,520
8,270
15,900
25,400
44,900
91,500
150
618
1,290
2,440
5,000
7,490
14,400
23,000
40,700
82,900
175
569
1,190
2,240
4,600
6,890
13,300
21,200
37,400
76,300
200
529
1,110
2,080
4,280
6,410
12,300
19,700
34,800
71,000
250
469
981
1,850
3,790
5,680
10,900
17,400
30,800
62,900
300
425
889
1,670
3,440
5,150
9,920
15,800
27,900
57,000
350
391
817
1,540
3,160
4,740
9,120
14,500
25,700
52,400
400
364
760
1,430
2,940
4,410
8,490
13,500
23,900
48,800
450
341
714
1,340
2,760
4,130
7,960
12,700
22,400
45,800
500
322
674
1,270
2,610
3,910
7,520
12,000
21,200
43,200
550
306
640
1,210
2,480
3,710
7,140
11,400
20,100
41,100
600
292
611
1,150
2,360
3,540
6,820
10,900
19,200
39,200
650
280
585
1,100
2,260
3,390
6,530
10,400
18,400
37,500
700
269
562
1,060
2,170
3,260
6,270
9,990
17,700
36,000
750
259
541
1,020
2,090
3,140
6,040
9,630
17,000
34,700
800
250
523
985
2,020
3,030
5,830
9,300
16,400
33,500
850
242
506
953
1,960
2,930
5,640
9,000
15,900
32,400
900
235
490
924
1,900
2,840
5,470
8,720
15,400
31,500
950
228
476
897
1,840
2,760
5,310
8,470
15,000
30,500
1,000
222
463
873
1,790
2,680
5,170
8,240
14,600
29,700
1,100
210
440
829
1,700
2,550
4,910
7,830
13,800
28,200
1,200
201
420
791
1,620
2,430
4,680
7,470
13,200
26,900
1,300
192
402
757
1,550
2,330
4,490
7,150
12,600
25,800
1,400
185
386
727
1,490
2,240
4,310
6,870
12,100
24,800
1,500
178
372
701
1,440
2,160
4,150
6,620
11,700
23,900
1,600
172
359
677
1,390
2,080
4,010
6,390
11,300
23,000
1,700
166
348
655
1,340
2,010
3,880
6,180
10,900
22,300
1,800
161
337
635
1,300
1,950
3,760
6,000
10,600
21,600
1,900
157
327 ,
617
1,270
1,900
3,650
5,820
10,300
21,000
2,000
152
318
600
1,230
1,840
3,550
5,660
10,000
20,400
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch - 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour == 0.0283 mlh, 1 degree = 0.01745 rad.
Note: All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.45
APPENDIX C
Gas
Undiluted Propane
TABLE C402.4(26)
SCHEDULE 40 METALLIC P!PE
Inlet Pressure
11.0in. w.c.
Pressure Drop
0.5 in. w.c.
Specific Gravity
1 .50
SPECIAL USE
Pipe sizing between first stage (high-pressure regulator) and second stage (low-pressure regulator).
PIPE SIZE (in.)
Nominal
V2
%
1
l'/4
I'll
2
2%
3
'4
Actual ID
0.622
0.824
1.049
1.380
1.610
2.067
2.469
3.068
4.026
Length (ft)
Capacity in Thousands of Btu per Hour
10
291
608
1,150
2,350
3,520
6,790
10,800
19,100
39,000
20
200
418
787
1,620
2,420
4,660
7,430
13,100
26,800
30
160
336
632
1,300
1,940
3,750
5,970
10,600
21,500
40
137
287
541
1,110
1,660
3,210
5,110
9,030
18,400
50
122
255
480
985
1,480
2,840
4,530
8,000
16,300
60
110
231
434
8921
1,340
2,570
4,100
7,250
14,800
80
101
212
400
821
1,230
2,370
3,770
6,670
13,600
100
94
197
372
763
1,140
2,200
3,510
6,210
12,700
125
89
185
349
716
1,070
2,070
3,290
5,820
11,900
150
84
175
330
677
1,010
1,950
3,110
5,500
11,200
175
74
155
292
600
899
1,730
2,760
4,880
9,950
200
67
140
265
543
814
1,570
2,500
4,420
9,010
250
62
129
243
500
749
1,440
2,300
4,060
8,290
300
58
120
227
465
697
1,340
2,140
3,780
7,710
350
51
107
201
412
618
1,190
1,900
3,350
6,840
400
46
97
182
373
560
1,080
1,720
3,040
6,190
450
42
89
167
344
515
991
1,580
2,790
5,700
500
40
83
156
320
479
922
1,470
2,600
5,300
550
37
78
146
300
449
865
1,380
2,440
4,970
600
35
73
138
283
424
817
1,300
2,300
4,700
650
33
70
131
269
403
776
1,240
2,190
4,460
700
32
66
125
257
385
741 ,
1,180
2,090
4,260
750
30
64
120
246
368
709
1,130
2,000
4,080
800
29
61
115
236
354
681
1,090
1,920
3,920
850
28
59
111
227
341
656
1,050
1,850
3,770
900
27
57
107
220
329
634
1,010
1,790
3,640
950
26
55
104
213
319
613
978
1,730
3,530
1,000
25
53
100
206
309
595
948
1,680
■3,420
1,100
25
52
97
200
300
578
921
1,630
3,320
1,200
24
50
95
195
292
562
895
1,580
3,230
1,300
23
48
90
185
277
534
850
1,500
3,070
1,400
22
46
86
176
264
509
811
1,430
2,930
1,500
21
44
82
169
253
487
777
1,370
2,800
1,600
20
42
79
162
243
468
746
1,320
2,690
1,700
19
40
76
156
234
451
719
1,270
2,590
1,800
19
39
74
151
226
436
694
1,230
2,500
1,900
18
38
71
146
219
422
672
1,190
2,420
2,000
18
37
69
142
212
409
652
1,150
2,350
For SI: 1 inch = 25.4 mm, 1 foot = 304. f
1 British thermal unit per hour =
Note: All table entries have been rounded
1 mm, 1 pound per square inch = 6.
0.2931 W, 1 cubic foot per hour =
to three significant digits.
895 kPa, 1-inch water column = 0.2488
0.0283 m%, 1 degree = 0.01745 rad.
kPa,
117.46
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C402.4(27)
SEMIRIGID COPPER TUBING
Gas
Undiluted Propane
Inlet Pressure
10.0 psi
Pressure Drop
1.0 psi
Specific Gravity
1.50
SPECIAL USE
Sizing between first stage (high-pressure
regulator) and second stage (low-pressure regulator).
TUBE SIZE (In.)
Nominal
K&L
•A
Vs
'/2
^/8
%
1
l'/4
l'/2
2
ACR
%
'/2
^/8
%
'/8
l'/8
iVs
—
Outside
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
Inside
0.305.
0.402
• 0.527
0.652
0.745
0.995
1.245
1.481
1.959
Length (ft)
Capacity in Thousands of Btu per Hour
10
513
1,060
2,150
3,760
5,330
1 1 ,400
20,500
32,300
67,400
20
352
727
1,480
2,580
3,670
7,830
14,100
22,200
46,300
30
283
584
1,190
2,080
2,940
6,290
11,300
17,900
37,200
40
242
500
1,020
1,780
2,520
5,380
9,690
15,300
31,800
50
215
443
901
1,570
2,230
4,770
8,590
13,500
28,200
60
194
401
816
1,430
2,020
4,320
7,780
12,300
25,600
70
179
369
751'
1,310
1,860
3,980
7,160
1 1,300
23,500
80
166
343
699
1,220
1,730
3,700
6,660
10,500
21,900
90
156
322
655 •
1,150
1,630
3,470
6,250
9,850
20,500
100
147
304
619
1,080
1,540
3,280
5,900
9,310
19,400
125
131
270
549
959
1,360
2,910
5,230
8,250
17,200
150
118
244
497
869
1,230
2,630
4,740
7,470
15,600
175
109
225
457
799
1,130
2,420
4,360
6,880
14,300
200
101
209
426
744
1,060
2,250
4,060
6,400
13,300
250
90
185
377
659
935
2,000
3,600
5,670
11,800
300
81
168
342
597
847
1,810
3,260
5,140
10,700
350
75
155
314
549
779
1,660
3,000
4,730
9,840
400
70
144
292
511
725
1,550
2,790
4,400
9,160
450
65
135
274
480
680
1,450
2,620
4,130
8,590
500
62
127
259
453
643
1,370
2,470
3,900
8,120
550
59
121
246
430
610
1,300
2,350
3,700
7,710
600
56
115
235
410
582
1,240
2,240
3,530
7,350
650
54
111
225
393
558
1,190
2,140
3,380
7,040
700
51
106
216
378
536
1,140
2,060
3,250
6,770
750
50
102
208
364
516
1,100
1,980
3,130
6,520
800
48
99
201
351
498
1,060
1,920
3,020
6,290
850
46
96
195
340
482
1,030
1,850
2,920
6,090
900
45
93
189
330
468
1,000
1,800
2,840
5,910
950
44
90
183
320
454
970
1,750
2,750
5,730
1,000
42
88
178
311
442
944
1,700
2,680
5,580
1,100
40
83
169
296
420
896
1,610
2,540
5,300
1,200
38
79
161
282
400
855
1,540
2,430
5,050
1,300
37
76
155
270
383
819
1,470
2,320
4,840
1,400
35
73
148
260
368
787
1,420
2,230
4,650
1,500
34
70
143
250
355
758
1,360
2,150
4,480
1,600
33
68
138
241
343
732
1,320
2,080
4,330
1,700
32
66
134
234
331
708
1,270
2,010
4,190
1,800
31
64
130
227
321
687
1,240
1,950
4,060
1,900
30
62
126
220
312
667
1,200
1,890
3,940
2,000
29
60
122
214
304
648
1,170
1,840
3,830
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour - 0.0283 m'/h, 1 degree = 6.01745 rad.
Notes:
1 . Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
2. All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.47
APPENDIX C
Gas
Undiluted Propane
TABLE C402.4(28)
SEMIRIGID COPPER TUBING
Inlet Pressure
11.0 in. w.c.
Pressure Drop
0.5 in. w.c.
Specific Gravity
1.50
SPECIAL USE
Sizing between first stage (high-pressure regulator) and second stage (low-pressure regulator)
TUBE SIZE (in.)
Nominal
K&L
'/4
'/s
'/2
%
%
1
IV4
l'/2
2
ACR
Vs
'/2
^/8
%
\
l'/8
1%
Outside
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
Inside
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
Length (ft)
Capacity in Thousands of Btu per Hour
10
45
93
188
329
467
997
1,800
2,830
5,890
20
31
64
129
226
321
685
1.230
1,950
4,050
30
25
51
104
182
258
550
991
1,560
3,250
40
21
44
89
155
220
471
848
1,340
2,780
50
19
39
79
138
195
417
752
1,180
2,470
60
17
35
71
125
177
378
681
1,070
2,240
70
16
32
66
115
163
348
626
988
2,060
80
15
30
61
107
152
324
583
919
1,910
90
14
28
57
100
142
304
547
862
1,800
100
13
27
54
95
134
287
517
814
1,700
125
11
24
48
84
119
254
458
722
1,500
150
10
21
44
76
108
230
415
654
1,360
175
NA
20
40
70
99
212
382
602
1,250
200
NA
18
37
65
92
197
355
560
1,170
250
NA
16
33
58
82
175
315
496
1,030
300
NA
15
30
52
74
158
285
449
936
350
NA
14
28
48
68
146
262
414
861
400
NA
13
26
45
63
136
244
385
801
450
NA
12
24
42
60
127
229
361
752
500
NA
11
23
40
56
120
216
341
710
550
NA
11
22
38
53
114
205
324
674
600
NA
10
21
36
51
109
196
309
643
650
NA
NA
20
34
49
104
188
296
616
700
NA
NA
19
33
47
100
180
284
592
750
NA
NA
18
32
45
96
174
274
570
800
NA
NA
18
31
44
93
168
264
551
850
NA
NA
17
30
42
90
162
256
533
900
NA
NA
17
29
41
87
157
248
517
950
NA
NA
16
28
40
85
153
241
502
1,000
NA
NA
16
27
39
83
149
234
488
1,100
NA
NA
15
26
37
78
141
223
464
1,200
NA
NA
14
25
35
75
135
212
442
1,300
NA
NA
14
24
34
72
129
203
423
1,400
NA
NA
13
23
32
69
124
195
407
1,500
NA
NA
13
22
31
66
119
188
392
1,600
NA
NA
12
21
30
64
115
182
378
1,700
NA
NA
12
20
29
62
112
176
366
1,800
NA
NA
11
20
28
60
108
170
355
1,900
NA
NA
11
19
27
58
105
166
345
2,000
NA
NA
11
19
27
57
102
161
335
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour - 0.0283 m'/h, 1 degree = 0.01745 rad.
Notes:
1. Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
2. NA means a flow of less than 10,000 Btu^r.
3. All table entries have been rounded to three significant digits.
117.48
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C402.4(29)
SEMIRIGID COPPER TUBING
Gas
Undiluted Propane
Inlet Pressure
2.0 psi
Pressure Drop
1 .0 psi
Specific Gravity
1.50
TUBE SIZE (In.)
Nominal
K&L
V4
^8
'/2
%
V4
1
IV4
IV2
2
ACR
%
V2
%
%
Vs
iVg
1%
—
—
Outside
0.375
0.500
0.625
0.750
0.875
1.125
1.375
1.625
2.125
Inside
0.305
0.402
0.527
0.652
0.745
0.995
1.245
1.481
1.959
Length (ft)
Capacity in Tiiousands of Btu per Hour
10
413
852
1,730
3,030
4,300
9,170
16,500
26,000
54,200
20
284
585
1,190
2,080
2,950
6,310
11,400
17,900
37,300
30
228
470
956
1,670
2,370
5,060
9,120
14,400
29,900
40
195
402
818
1,430
2,030
4,330
7,800
12,300
25,600
50
173
356
725
1,270
1,800
3,840
6,920
10,900
22,700
60
157
323
657
1,150
1,630
3,480
6,270
9,880
20,600
70
144
297
605
1,060
1,500
3,200
5,760
9,090
18,900
80
134
276
562
983
1,390
2,980
5,360
8,450
17,600
90
126
259
528
922
1,310
2,790
5,030
7,930
16,500
100
119
245
498
871
1,240
2,640
4,750
7,490
15,600
125
105
217
442
772
1,100
2,340
4,210
6,640
13,800
150
95
197
400
700
992
2,120
3,820
6,020
12,500
175
88
181
368
644
913
1,950
3,510
5,540
11,500
200
82
168
343
599
849
1,810
3,270
5,150
10,700
250
72
149
304
531
753
1,610
2,900
4,560
9,510
300
66
135
275
481
682
1,460
2,620
4,140
8,610
350
60
124
253
442
628
1,340
2,410
3,800
7,920
400
56
116
235
411
584
1,250
2,250
3,540
7,370
450
53
109
221
386
548
1,170
2,110
3,320
6,920
500
50
103
209
365
517
1,110
1,990
3,140
6,530
550
47
97
198
346
491
1,050
1,890
2,980
6,210
600
45
93
189
330
469
1,000
1,800
2,840
5,920
650
43
89
181
316
449
959
1,730
2,720
5,670
700
41
86
174
304
431
921
1,660
2,620
5,450
750
40
82
168
293
415
888
1,600
2,520
5,250
800
39
80
162
283
401
857
1,540
2,430
5,070
850
37
77
157
274
388
829
1,490
2,350
4,900
900
36
75
152
265
376
804
1,450
2,280
4,750
950
35
72
147
258
366
L 781
1,410
2,220
4,620
1,000
34
71
143
251
356
760
1,370
2,160
4,490
1,100
32
67
136
238
338
721
1,300
2,050
4,270
1,200
31
64
130
227
322
688
1,240
1,950
4,070
1,300
30
61
124
217
309
659
1,190
1,870
3,900
1,400
28
59
120
209
296
633
1,140
1,800
3,740
1,500
27
57
115
201
286
610
1,100
1,730
3,610
1,600
26
55 ,,
111
194
276
589
1,060
1,670
3,480
1,700
26 ■
53
108
188
267
570
1,030
1,620
3,370
1,800
25
51
104
182
259
553
1,000
1,570
3,270
1,900
24
50
101
177
251
537
966
1,520
3,170
2,000
23
48
99
172
244
522
940
1,480
3,090
For SI:
Notes:
1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour - 0.2931 W, 1 cubic foot per hour - 0.0283 m'/h, 1 degree = 0.01745 rad.
1 . Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
2. All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.49
APPENDIX C
Gas
Jncliluted Propane
TABLE C402.4(30)
CORRUGATED STAINLESS STEEL TUBING (CSST)
Inlet Pressure
1.0 in. w.c.
Pressure Drop (
).5 in. w.c.
Specific Gravity
.50
TUBE SIZE (EHD)
Flow
Designation
13
15
18
19
23
25
30
31
37
46
48
60
62
Length (ft)
Capacity in Thousands of Btu per Hour
5
72
99
181
211
355
426
744
863
1,420
2,830
3,270
5,780
6,550
10
50
69
129
150
254
303
. 521
605
971
1,990
2,320
4,110
4,640
15
39
55
104
121
208
248
422
490
775
1,620
1,900
3,370
3,790
20
34
49
91
106
183
216
365
425
661
1,400
1,650
2,930
3,290
25
30
42
82
94
164
192
325
379
583
1,250
1,480
2,630
2,940
30
28
39
74
87
151
177
297
344
528
1,140
1,350
2,400
2,680
40
23
33
64
74
131
153
256
297
449
988
1,170
2,090
2,330
50
20
30
58
66
118
137
227
265
397
884
1,050
1,870
2,080
60
19
26
53
60
107
126
207
241
359
805
961 ! 1,710
1,900
70
17
25
49
57
99
117
191
222
330
745
890
1,590
1,760
80
15
23
45
52
94
109
178
208
307
696
833
1,490
1,650
90
15
22
44
50
90
102
169
197
286
656
787
1,400
1,550
100
14
20
41
47
85
98
159
186
270
621
746
1,330
1,480
150
11
15
31
36
66
75
123
143
217
L 506
611
1,090
1,210
200
9
14
28
33
60
69
112
129
183
438
531
948
1,050
250
8
12
25
30
53
61
99
117
163
390
476
850
934
300
8
11
23
26
50
57
90
107
147
357
434
777
854
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square incii = 6.895kPa, 1-inch water column = 0.2488 icPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 nv'/h, 1 degree = 0.01745 rad.
Notes:
1 . Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent
length of tubing to the following equation: L = 1.3« where L is additional length (feet) of tubing and n is the number of additional fittings and/or bends.
2. EHD — Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the
greater the gas capacity of the tubing.
3. All table entries have been rounded to three significant digits.
117.50
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
Gas I
Jndiluted Propane
TABLE C402.4(31)
CORRUGATED STAINLESS STEEL TUBING (CSST)
Inlet Pressure 2
?.0 psi
Pressure Drop
.0 psi
Specific Gravity
.50
TUBE SIZE (EHD)
Flow
Designation
13
15
18
19 23
25
30
31
37
46
48
60
62
Length (ft)
Capacity in Thousands of Btu per Hour
10
426
558
■927
1,110
1,740
2,170
4,100
4,720
7,130
15,200
16,800
29,400
34,200
25
262
347
591
701
1,120
1,380
2,560
2,950
4,560
9,550
10,700
18,800
21,700
30
238
316
540
640
1,030
1,270
2,330
2,690
4,180
8,710
9,790
17,200
19,800
40
203
271
469
554
896
1,100
2,010
2,320
3,630
7,530
8,500
14,900
17,200
50
181
243
420
496
806
986
1,790
2,070
3,260
6,730
7,610
13,400
15,400
75
147
196
344
406
663
809
1,460
1,690
2,680
5,480
6,230
11,000
12,600
80
140
189
333
393
643
768
1,410
1,630.
2,590
5,300
6,040
10,600
12,200
100
124
169
298
350
578
703
1,260
1,450
2,330
4,740
5,410
9,530
10,900
• 150
101
137
245
287
477
575
1,020
1,180
1,910
3,860
4,430
7,810
8,890
200
[ 86
118
213
248
415
501
880
1,020
1,660
3,340
3,840
6,780
7,710
250
' 77
105
191
222
373
448
785
910
1,490
2,980
3,440
6,080
6,900
300
69
96
173
203
343
411
716
829
1,360
2,720
3,150
5,560
6,300
400
60
82
151
175
298
355
616
716
1,160
2,350
2,730
4,830
5,460
500
53
72
135
158
268
319
550
638
1,030
2,100
2,450
4,330
4,880
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m^/h, 1 degree = 0.01745 rad.
Notes:
1 . Table does not include effect of pressure drop across the line regulator. Where regulator loss exceeds Vj psi (based on 1 3 in. w.c. outlet pressure), DO NOT USE
THIS TABLE. Consult with the regulator manufacturer for pressure drops and capacity factors. Pressure drops across a regulator may vary with flow rate.
2. CAUTION: Capacities shown in the table might exceed maximum capacity for a selected regulator. Consult with the regulator or tubing manufacturer for guid-
ance.
3. Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent
length of tubing to the following equation: L = \.3n where L is additional length (feet) of tubing and n is the number of additional fittings and/or bends.
4. EHD — Equivalent Hydrauhc Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the
greater the gas capacity of the tubing.
5. All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.51
APPENDIX C
Gas I
Jndiluted Propane
TABLE C402.4(32)
CORRUGATED STAINLESS STEEL TUBING (CSST)
Inlet Pressure J
5.0 psi
Pressure Drop C
3.5 psi
Specific Gravity
.50
TUBE SIZE (EHD)
Flow
Designation
13
15
18
19
23
25
30
31.
37
46
48
60
62
Length (ft)
Capacity in Thousands of Btu per Hour
10
826
1,070
1,710
2,060
3,150
4,000
7,830
8,950
13,100
28,600
31,200
54,400
63,800
25
509
664
1,090
1,310
2,040
2,550
4,860
5,600
8,400
18,000
19,900
34,700
40,400
30
461
603
999
1,190
1,870
2,340
4,430
5,100
7,680
16,400
18,200
31,700
36,900
40
396
520
867
1,030
1,630
2,030
3,820
4,400
6,680
14,200
15,800
27,600
32,000
50
352
463
777
926
1,460
1,820
3,410
3,930
5,990
12,700
14,100
24,700
28,600
75
284
376
637
757
1,210
1,490
2,770
3,190
4,920
10,300
11,600
20,300
23,400
80
275
363
618
731
1,170
1,450
2,680
3,090
4,770
9,990
11,200
19,600
22,700
100
243
324
553
656
1,050
1,300
2,390
2,760
4,280
8,930
10,000
17,600
20,300
150
196
262
453
535
866
1,060
1,940
2,240
3,510
7,270
8,210
14,400
16,600
200
169
226
393
464
755
923
1,680
1,930
3,050
6,290
7,130
12,500
14,400
250
150
202
352
415
679
828
1,490
1,730
2,740
5,620
6,390
11,200
12,900
300
136
183
322
379
622
757
1,360
1,570
2,510
5,120
5,840
10,300
11,700
400
117
158
279
328
542
657
1,170
1,360
2,180
4,430
5,070
8,920
10,200
500
104
140
251
294
488
589
1,050
1,210
1,950
3,960
4,540
8,000
9,110
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 rn^/h, 1 degree = 0.01745 rad.
Notes:
1. Table does not include effect of pressure drop across line regulator. Where regulator loss exceeds 1 psi, DO NOT USE THIS TABLE. Consult with the regulator
manufacturer for pressure drops and capacity factors. Pressure drop across regulator may vary with the flow rate.
2. CAUTION: Capacities shown in the table may exceed maximum capacity of selected regulator. Consult with the tubing manufacturer for guidance.
3. Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be inci^eased by an equivalent
length of tubing to the following equation: L = 1 .3n where L is additional length (feet) of tubing and n is the number of addifional fittings and/or bends.
4. EHD — Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the
greater the gas capacity of the tubing.
5. All table entries have been rounded to three significant digits.
117.52
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C402.4(33)
POLYETHYLENE PLASTIC PIPE
Gas
Undiluted Propane
Inlet Pressure
11.0 in. w.c.
Pressure Drop
0.5 in. w.c.
Specific Gravity
1.50
PIPE SIZE (in.)
Nominal OD
'/a
%
1
l'/4
IV2
2
Designation
SDR 9.33
SDR 11.0
SDR 11.00
SDR 10.00
SDR 11.00
SDR 11.00
Actual ID
0.660
0.860
1.077
1.328
1.554
1.943
Length (ft)
Capacity in Thousands of Btu per Hour
10
340
680
1,230
2,130
3,210
5,770
20
233
468
844
1,460
2,210
3,970
30
187
375
677
1,170
1,770
3,180
40
160
321
580
1,000
1,520
2,730
50
142
285
514
890
1,340
2,420
60
129
258
466
807
1,220
2,190
70
119
237
428
742
1,120
2,010
80
110
221
398
690
1,040
1,870
90
103
207
374
648
978
1,760
100
98
196
353
612
924
1,660
125
87
173
313
542
819
1,470
150
78
157
284
491
742
1,330
175
72
145
261
452
683
1,230
200
67
135
243
420
635
1,140
250
60
119
215
373
563
1,010
300
54
108
195
338
510
916
350
50
99
179
311
469
843
400
46
92
167
289
436
784
450
43
87
157
271
409
736
500
41
82
148
256
387
695
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, I pound per square inch = 6.895kPa, 1-inch water column = 0.2488 icPa,
1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 nr'/h, 1 degree = 0.01745 rad.
Note: All table entries have been rounded to three significant digits.
2007 OREGON MECHANICAL SPECIALTY CODE
117.53
APPENDIX C
TABLE C402.4(34)
POLYETHYLENE PLASTIC PIPE
Gas
Undiluted Propane
Inlet Pressure
2.0 psi
Pressure Drop
1.0 psi
Specific Gravity
1.50
PIPE SIZE (in.)
Nominal OD
V2
'U
1
IV4
IV2
2
Designation
SDR 9.33
SDR 11.0
SDR 11.00
SDR 10.00
SDR 11.00
SDR 11.00
Actual ID
0.660
0.860
1.077
1.328
1.554
1.943
Length (ft)
Capacity in Thousands of Btu per Hour
10
3,130
6,260
11,300
19,600
29,500
53,100
20
2,150
4,300
7,760
13,400
20,300
36,500
30
1,730
3,450
6,230
10,800
16,300
29,300
40
1,480
2,960
5,330
9,240
14,000
25,100
50
1,310
2,620
4,730
8,190
12,400
22,200
60
1,190
2,370
4,280
7,420
11,200
20,100
70
1,090
2,180
3,940
6,830
10,300
18,500
80
1,010
2,030
3,670
6,350
9,590
17,200
90
952
1,910
3,440
5,960
9,000
16,200
100
899
1,800
3,250
5,630
8,500
15,300
125
797
1,600
2,880
4,990
7,530
13,500
150
722
1,450
2,610
4,520
6,830
12,300
175
664
1,330
2,400
4,160
6,280
11,300
200
618
1,240
2,230
3,870
5,840
10,500
250
548
1,100
1,980
3,430
5,180
9,300
300
496
994
1,790
3,110
4,690
8,430
350
457
914
1,650
2,860
4,320
7,760
400
425
851
1,530
2,660
4,020
7,220
450
399
798
1,440
2,500
3,770
6,770
500
377
754
1,360
2,360
3,560
6,390
550
358
716
1,290
2,240
3,380
6,070
600
341
683
1,230
2,140
3,220
5,790
650
327
654
1,180
2,040
3,090
5,550
700
314
628
1,130
1,960
2,970
5,330
750
302
605
1,090
1,890
2,860
5,140
800
292
585
1,050
1,830
2,760
4,960
850
283
566
1,020
1,770
2,670
4,800
900
274
549
990
1,710
2,590
4,650
950
266
533
961
1,670
2,520
4,520
1,000
259
518
935
1,620
2,450
4,400
1,100
246
492
888
1,540
2,320
4,170
1,200
234
470
847
1,470
2,220
3,980
1,300
225
450
811
1,410
2,120
3,810
1,400
216
432
779
1,350
2,040
3,660
1,500
208
416
751
1,300
1,960
3,530
1,600
201
402
725
1,260
1,900
3,410
1,700
194
389
702
1,220
1,840
3,300
1,800
188
377
680
1,180
1,780
3,200
1,900
183
366
661
1,140
1,730
3,110
2,000
178
356
643
1,110
1,680
■3,020
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm,
1 British thermal unit per hour = 0.293
Note: All table entries have been rounded to three si
1 pound per square inch = 6,
1 W, 1 cubic foot per hour =
gnificant digits.
895 kPa, 1-inch water column = 0.2488 kPa,
0.0283 m'/h, 1 degree = 0.01745 rad.
117.54
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C402.4(35)
POLYETHYLENE PLASTIC TUBING
Gas
Undiluted Propane
Inlet Pressure
11.0 in. w.c.
Pressure Drop
0.5 in. w.c.
Specific Gravity
1.50
Plastic Tubing Size (CTS) (in.)
Nominal OD
%
'U
Designation
SDR 7.00"
SDR 11.00
Actual ID
0.445
0.927
Length (ft)
Capacity in Cubic Feet of Gas per Hour
10
121
828
20
83
569
30
67
457
40
57
391
50
51
347
60
46
314
70
42
289
80
39
269
90
37
252
100
35
238
125
31
211
150
28
191
175
26
176
200
24
164
225
22
154
250
21
145
275
20
138
300
19
132
350
18
121
400
16
113
450
15
106
500
15
100
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm,
1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa,
1 British thermal unit per hour = 0.293 1 W, 1 cubic foot per hour = 0.0283 ml\\,
1 degree = 0.01745 rad.
SECTION C403
PIPING MATERIALS
C403.1 General. Materials used for piping systems shall com-
ply with the requirements of this chapter or shall be approved.
C403.2 Used materials. Pipe, fittings, valves and other materi-
als shall not be used again except where they are free of foreign
materials and have been ascertained to be adequate for the ser-
vice intended.
C403.3 Metallic pipe. Metallic pipe shall comply with Sec-
tions C403.3.1 through C403.3.4.
C403.3.1 Cast iron. Cast-iron pipe shall not be used.
C403.3.2 Steel. Steel and wrought-iron pipe shall be at least
of standard weight (Schedule 40) and shall comply with one
of the following standards:
1. ASME B 36.10, lOM;
2. ASTM A 53; or
3. ASTM A 106.
C403.3.3 Copper and brass. Copper and brass pipe shall
not be used if the gas contains more than an average of 0.3
grains of hydrogen sulfide per 100 standard cubic feet of gas
(0.7 milligrams per 100 liters). Threaded copper, brass and
aluminum-alloy pipe shall not be used with gases corrosive
to such materials.
C403.3.4 Aluminum. Aluminum-alloy pipe shall comply
with ASTM B 241 (except that the use of alloy 5456 is prohib-
ited), and shall be marked at each end of each length indicating
compliance. Aluminum-alloy pipe shall be coated to protect
against external corrosion where it is in contact with masonry,
plaster, or insulation, or is subject to repeated wettings by such
liquids as water, detergents, or sewage. Aluminum-alloy pipe
shall not be used in exterior locations or underground.
C403.4 Metallic tubing. Seamless copper, aluminum alloy
and steel tubing shall not be used with gases corrosive to such
materials,
C403.4.1 Steel tubing. Steel tubing shall comply with
ASTM A 254 or ASTM A 539.
C403.4.2 Copper and brass tubing. Copper tubing shall
comply with Standard Type K or L of ASTM B 88 or ASTM
B 280.
Copper and brass tubing shall not be used if the gas con-
tains more than an average of 0.3 grains of hydrogen sulfide
per 100 standard cubic feet of gas (0.7 milligrams per 100
liters).
C403.4.3 Aluminum tubing. Aluminum-alloy tubing shall
comply with ASTM B 210 or ASTM B 241. Alumi-
num-alloy tubing shall be coated to protect against external
corrosion where it is in contact with masonry, plaster or
insulation, or is subject to repeated wettings by such liquids
as water, detergent or sewage.
Aluminum-alloy tubing shall not be used in exterior loca-
tions or underground.
C403.4.4 Corrugated stainless steel tubing. Corrugated
stainless steel tubing shall be listed in accordance with
ANSI LC 1/CSA 6.26.
C403.5 Plastic pipe, tubing and fittings. Plastic pipe, tubing
and fittings used to supply fuel gas shall be used outdoors,
underground, only, and shall conform to ASTM D 2513. Pipe
shall be marked "Gas" and "ASTM D 2513."
C403.5.1 Anodeless risers. Plastic pipe, tubing and
anodeless risers shall comply with the following:
1. Factory-assembled anodeless risers shall be recom-
mended by the manufacturer for the gas used and
<
2007 OREGON MECHANICAL SPECIALTY CODE
117.55
APPENDIX C
shall be leak tested by the manufacturer in accordance
with written procedures.
2. Service head adapters and field-assembled anodeless
risers incorporating service head adapters shall be
recommended by the manufacturer for the gas used,
and shall be designed and certified to meet the
requirements of Category I of ASTM D 2513, and
U.S. Department of Transportation, Code of Federal
Regulations, Title 49, Part 192.281(e). The manufac-
turer shall provide the user with qualified installation
instructions as prescribed by the U.S. Department of
Transportation, Code of Federal Regulations, Title
49, Part 192.283(b).
TABLE C403.8.2
SPECIFICATIONS FOR THREADING METALLIC PIPE
.2 LP-gas systems. The use of plastic pipe, tubing
and fittings in undiluted liquefied petroleum gas piping sys-
tems shall be in accordance with NFPA 58.
L53 Regulator vent piping. Plastic pipe, tubing and
fittings used to connect regulator vents to remote vent termi-
nations shall be PVC conforming to UL 65 1 . PVC vent pip-
ing shall not be installed indoors.
C4(D>3.6 Workmanship and defects. Pipe, tubing and fittings
shall be clear and free from cutting burrs and defects in struc-
ture or threading, and shall be thoroughly brushed, and chip
and scale blown.
Defects in pipe, tubing and fittings shall not be repaired.
Defective pipe, tubing and fittings shall be replaced (see Sec-
tion C406. 1.2).
C403,7 Protective coating. Where in contact with material or
atmosphere exerting a corrosive action, metallic piping and fit-
tings coated with a corrosion-resistant material shall be used.
External or internal coatings or linings used on piping or com-
ponents shall not be considered as adding strength.
C403.8 Metallic pipe threads. Metallic pipe and fitting threads
shall be taper pipe threads and shall comply with ASME B 1 .20. 1 .
L8.1 Damaged threads. Pipe with threads that are
stripped, chipped, corroded or otherwise damaged shall not
be used. Where a weld opens during the operation of cutting
or threading, that portion of the pipe shall not be used.
C403.8.2 Number of threads. Field threading of metallic
pipe shall be in accordance with Table C403.8.2.
IM3 Thread compounds. Thread (joint) compounds
(pipe dope) shall be resistant to the action of liquefied petro-
leum gas or to any other chemical constituents of the gases
to be conducted through the piping.
I Metallic piping joints and fittings. The type of piping
joint used shall be suitable for the pressure-temperature condi-
tions and shall be selected giving consideration to joint tight-
ness and mechanical strength under the service conditions. The
joint shall be able to sustain the maximum end force caused by
the internal pressure and any additional forces caused by tem-
perature expansion or contraction, vibration, fatigue or the
weight of the pipe and its contents.
IRON PIPE SIZE
(inches)
APPROXIMATE LENGTH OF
THREADED PORTION (inches)
APPROXIMATE NUMBER
OF THREADS TO BE CUT
%
'U
10
'U
%
10
1
%
10
1V4
1
u
iv.
1
u
2
1
11
2%
1%
12
3
\%
12
4
1%
13
For SL- 1 inch = 25.4 mm.
C403.9.1 Pipe joints. Pipe joints shall be threaded, flanged,
brazed or welded. Where nonferrous pipe is brazed, the
brazing materials shall have a melting point in excess of
1,000°F (538°C). Brazing alloys shall not contain more than
0.05-percent phosphorus.
C403.9.2 Tiibing joints. Tubing joints shall be either made
with approved gas tubing fittings or brazed with a material
having a melting point in excess of 1,000°F (538°C). Brazing
alloys shall not contain more than 0.05-percent phosphorus.
C403.9.3 Flared joints. Flared joints shall be used only in
systems constructed from nonferrous pipe and tubing where
experience or tests have demonstrated that the joint is suit-
able for the conditions and where provisions are made in the
design to prevent separation of the joints.
C403.9.4 Metallic fittings. MetalUc fittings shall comply
with the following:
1. Threaded fittings in sizes larger than 4 inches (102
mm) shall not be used except where approved.
2. Fittings used with steel or wrought-iron pipe shall be
steel, brass, bronze, malleable iron or cast iron.
3. Fittings used with copper or brass pipe shall be cop-
per, brass or bronze.
4. Fittings used with aluminum- alloy pipe shall be of
aluminum alloy.
5. Cast-iron fittings:
5.1. Ranges shall be permitted.
5.2. Bushings shall not be used.
5.3. Fittings shall not be used in systems contain-
ing flammable gas-air mixtures.
5.4. Fittings in sizes 4 inches (102 mm) and larger
shall not be used indoors except where ap-
proved.
5.5. Fittings in sizes 6 inches (152 mm) and larger
shall not be used except where approved.
117.56
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
6. Aluminum-alloy fittings.! Threads shall not form the
joint seal.
7. Zinc aluminum-alloy fittings. Fittings shall not be
used in systems containing flammable gas-air mix-
tures.
8. Special fittings. Fittings such as couplings, propri-
etary-type joints, saddle tees, gland-type compres-
sion fittings, and flared, flareless or compression-type
tubing fittings shall be: used within the fitting manu-
facturer's pressure-temperature recommendations;
used within the service conditions anticipated with
respect to vibration, fatigue, thermal expansion or
contraction; installed or braced to prevent separation
of the joint by gas pressure or external physical dam-
age; and shall be approved.
C403.10 Plastic pipe, joints and fittings. Plastic pipe, tubing
and fittings shall be joined in accordance with the manufac-
turer's instructions. Such joint shall comply with the following:
1 . The joint shall be designed and installed so that the longi-
tudinal pull-out resistance of the joint will be at least
equal to the tensile strength of the plastic piping material.
2. Heat-fusion joints shall be made in accordance with
qualified procedures that have been established and
proven by test to produce gas-tight joints at least as
strong as the pipe or tubing being joined. Joints shall be
made with the joining method recommended by the pipe
manufacturer. Heat fusion fittings shall be marked
"ASTMD2513."
3. Where compression-type mechanical joints are used, the
gasket material in the fitting shall be compatible with the
plastic piping and with the gas distributed by the system.
An internal tubular rigid stiffener shall be used in con-
junction with the fitting. The stiffener shall be flush with
the end of the pipe or tubing and shall extend at least to
the outside end of the compression fitting when installed.
The stiffener shall be free of rough or sharp edges and
shall not be a force fit in the plastic. Split tubular stiffen-
ers shall not be used.
4. Plastic piping joints and fittings for use in liquefied
petroleum gas piping systems shall be in accordance
with NFPA 58.
C403.ll Flanges. All flanges shall comply with ASME B 1 6. 1 ,
ASME B 16.20 or MSS SP-6. The pressure-temperature ratings
shall equal or exceed that required by the application.
C403.11.1 Flange facings. Standard facings shall be per-
mitted for use under this code. Where 150-pound (1034
kPa) pressure-rated steel flanges are bolted to Class 125
cast-iron flanges, the raised face on the steel flange shall be
removed.
C403.11.2 Lapped flanges. Lapped flanges shall be used
only above ground or in exposed locations accessible for
inspection.
C403.12 Flange gaskets. Material for gaskets shall be capable
of withstanding the design temperature and pressure of the pip-
ing system, and the chemical constituents of the gas being con-
ducted, without change to its chemical and physical properties.
The effects of fire exposure to the joint shall be considered in
choosing material. Acceptable materials include metal or
metal-jacketed asbestos (plain or corrugated), asbestos, and
aluminum "O" rings and spiral wound metal gaskets. When a
flanged joint is opened, the gasket shall be replaced. Full-face
gaskets shall be used with all bronze and cast-iron flanges.
SECTION C404
PIPING SYSTEM INSTALLATION
C404.1 Prohibited locations. Piping shall not be installed in
or through a circulating air duct, clothes chute, chimney or gas
vent, ventilating duct, dumbwaiter or elevator shaft. Piping
installed downstream of the point of delivery shall not extend
through any townhouse unit other than the unit served by such
piping.
C404.2 Piping in solid partitions and walls. Concealed pip-
ing shall not be located in solid partitions and solid walls,
unless installed in a chase or casing.
C404.3 Piping in concealed locations. Portions of a piping
system installed in concealed locations shall not have unions,
tubing fittings, right and left couplings, bushings, compression
couplings and swing joints made by combinations of fittings.
Exceptions:
1. Tubingjoined by brazing.
2. Fittings listed for use in concealed locations.
C404.4 Piping through foundation wall. Underground pip-
ing, where installed below grade through the outer foundation
or basement wall of a building, shall be encased in a protective
pipe sleeve. The annular space between the gas piping and the
sleeve shall be sealed.
C404.5 Protection against physical damage. In concealed
locations, where piping other than black or galvanized steel is
installed through holes or notches in wood studs, joists, rafters
or similar members less than 1.5 inches (38 mm) from the
nearest edge of the member, the pipe shall be protected by
shield plates. Shield plates shall be a minimum of
Vi6-inch-thick (1.6 mm) steel, shall cover the area of the pipe
where the member is notched or bored and shall extend a mini-
mum of 2 inches (51 mm) above sole plates, below top plates
and to each side of a stud, joist or rafter.
C404.6 Piping in solid floors. Piping in solid floors shall be
laid in channels in the floor and covered in a manner that will
allow access to the piping with a minimum amount of damage
to the building. Where such piping is subject to exposure to
excessive moisture or corrosive substances, the piping shall be
protected in an approved manner. As an alternative to installa-
tion in channels, the piping shall be installed in a conduit of
Schedule 40 steel, wrought iron, PVC or ABS pipe with tightly
sealed ends and joints. Both ends of such conduit shall extend
not less than 2 inches (5 1 mm) beyond the point where the pipe
emerges from the floor. The conduit shall be vented above
grade to the outdoors and shall be installed so as to prevent the
entry of water and insects.
C404.7 Above-ground outdoor piping. All piping installed
outdoors shall be elevated not less than VI2 inches (152 mm)
2007 OREGON MECHANICAL SPECIALTY CODE
117.57
APPENDIX C
>
above ground and where installed across roof surfaces, shall be
elevated not less than 3 Vj inches (152 mm) above the roof sur-
face. Piping installed above ground, outdoors, and installed
across the surface of roofs shall be securely supported and
located where it will be protected from physical damage.
Where passing through an outside wall, the piping shall also be
protected against corrosion by coating or wrapping with an
inert material. Where piping is encased in a protective pipe
sleeve, the annular space between the piping and the sleeve
shall be sealed.
€404.8 Corrosiom and covering protection. Nonmetallic gas
piping and coated and cathodically protected piping shall have
a minimum of 18 inches (457 mm) of earth cover or other
equivalent protection. Risers, including prefabricated risers
inserted with plastic pipe, shall be metallic and shall be pro-
tected in an approved manner to a point at least 6 inches (153
mm) above grade. When a riser connects to plastic pipe under-
ground, the horizontal metallic portion underground shall be at
least 30 inches (762 mm) in length before connecting to the
plastic service pipe. An approved transition fitting or adapter
shall be used where the plastic joins the metallic riser.
Ferrous metals in exposed exterior locations shall be pro-
tected from corrosion in a manner approved by the building
official after consulting with the gas supplier.
Ferrous pipes installed underground shall not be placed in
contact with other metallic objects such as pipes or wires.
Zinc coatings (galvanizing) shall not be deemed adequate
protection for piping below grade. Ferrous gas piping installed
underground in exterior locations shall be protected from cor-
rosion by one of the following methods:
C404.8.1 Coated and cathodically protected pipe. All gas
pipe protective coatings shall be approved types, machine
applied and conform to recognized standards. Field wrap-
ping shall provide equivalent protection and is restricted to
those short sections and fittings necessarily stripped for
threading or welding. Underground coated and wrapped gas
piping shall be cathodically protected with galvanic anodes
or rectifiers and electrically isolated from the rest of the sys-
tem by insulating unions 6 inches (153 mm) above grade.
C404.8,2 Unwrapped (toare) pipe and special covering.
Unwrapped ferrous gas piping being installed underground
in exterior locations shall be protected from corrosion by
being installed within a minimum 6-inch (153 mm) protec-
tive bed of sand around the gas piping, the pipe being cen-
trally located within the sand backfill, and all such
horizontal piping shall have a minimum of 18 inches (457
mm) of earth cover or other equivalent protection. Under-
ground piping shall be electrically isolated from the rest of
the system by insulating unions placed a minimum of 6
inches (153 mm) above grade.
€404.8.3 Electrical isolation of fuel gas piping. Under-
ground ferrous gas piping shall be electrically isolated from
the rest of the gas system with listed or approved isolation
fittings installed a minimum of 6 inches (153 mm) above
grade.
C404.9 Minimum burial depth. Underground piping systems
shall be installed a minimum depth of 12 inches (305 mm)
below grade, except as provided for in Section C404.9.1 .
C404.9.1 Individual outside appliances. Individual lines
to outside lights, grills or other appliances shall be installed
a minimum of 8 inches (203 mm) below finished grade, pro-
vided that such installation is approved and is installed in
locations not susceptible to physical damage.
0) Trenches. The trench shall be graded so that the pipe
has a firm, substantially continuous bearing on the bottom of
the trench.
[).l Underground gas pipe separation. Under-
ground gas piping shall be separated vertically or horizon-
tally from other underground piping as follows:
1. Sewer pipe^ — not less than 18 inches (457 mm) from
any underground sewer line.
2. Water pipe — not less than 12 inches (305 mm) from
any underground water line.
3. Drainage pipe — not less than 12 inches (305 mm)
from any underground drainage line.
C404.ll Piping underground beneath buildings. Piping
installed underground beneath buildings is prohibited except
where the piping is encased in a conduit of wrought iron, plas-
tic pipe, or steel pipe designed to withstand the superimposed
loads. Such conduit shall extend into an occupiable portion of
the building and, at the point where the conduit terminates in
the building, the space between the conduit and the gas piping
shall be sealed to prevent the possible entrance of any gas leak-
age. Where the end sealing is capable of withstanding the full
pressure of the gas pipe, the conduit shall be designed for the
same pressure as the pipe. Such conduit shall extend not less
than 4 inches (102 mm) outside the building, shall be vented
above grade to the outdoors, and shall be installed so as to pre-
vent the entrance of water and insects. The conduit shall be pro-
tected from corrosion in accordance with Section C404.8.
C404.12 Outlet closures. Gas outlets that do not connect to
appliances shall be capped gas tight.
Exception: Listed and labeled flush-mounted- type quick-
disconnect devices and Msted and labeled gas convenience
outlets shall be installed in accordance with the manufac-
turer's installation instructions.
C404.13 Location of outlets. The unthreaded portion of pip-
ing outlets shall extend not less than 1 inch (25 mm) through fin-
ished ceilings and walls and where extending through floors or
outdoor patios and slabs, shall not be less than 2 inches (51
mm) above them. The outlet fitting or piping shall be securely
supported. Outlets shall not be placed behind doors. Outlets
shall be located in the room or space where the appliance is
installed.
Exception: Listed and labeled flush-mounted-type quick-
disconnect devices and listed and labeled gas convenience
outlets shall be installed in accordance with the manufac-
turer's installation instructions.
C404.14 Plastic pipe. The installation of plastic pipe shall
comply with Sections C404.14.1 through C404.14.3.
117.58
2007 OREGON MECHANICAL SPECBALTY CODE
APPENDIX C
C404,14.1 Limitations. Plastic pipe shall be installed out-
side underground only. Plastic pipe shall not be used within
or under any building or slab or be operated at pressures
greater than 100 psig (689 kPa) for natural gas or 30 psig
(207 kPa) for LP-gas.
Exceptions;
1 . Plastic pipe shall be permitted to terminate above
ground outside of buildings where installed in
premanufactured anodeless risers or service head
adapter risers that are installed in accordance with
the manufacturer's installation instructions.
2. Plastic pipe shall be permitted to terminate with a
wall head adapter within buildings where the plas-
tic pipe is inserted in a piping material for fuel gas
use in buildings.
3 . Plastic pipe shall be permitted to be installed under
outdoor patios, walkways and driveways.
C404.14.2 Connections. Connections made outside and
underground between metallic and plastic piping shall be
made only with transition fittings categorized as Category I
in accordance with ASTM D 25 1 3 .
13 Tracer. A yellow insulated copper tracer wire or
other approved conductor shall be installed adjacent tp
underground nonmetallic piping. Access shall be provided
to the tracer wire or the tracer wire shall terminate above
ground at each end of the nonmetallic piping. The tracer
wire size shall not be less than 18 AWG and the insulation
type shall be suitable for direct burial.
.15 Prohibited devices. A device shall not be placed
inside the piping or fittings that will reduce the cross-sectional
area or otherwise obstruct the free flow of gas.
Exception: Approved gas filters.
C404.16 Testing of piping. Before any system of piping is put
in service or concealed, it shall be tested to ensure that it is gas
tight. Testing, inspection and purging of piping systems shall
comply with Section C406.
SECTION C405
PIPING BENDS AND CHANGES IN DIRECTION
C405.1 General. Changes in direction of pipe shall be permit-
ted to be made by the use of fittings, factory bends, or field
bends.
C405.2 Metallic pipe. Metallic pipe bends shall comply with
the following:
1. Bends shall be made only with bending tools and proce-
dures intended for that purpose.
2. All bends shall be smooth and free from buckling, cracks
or other evidence of mechanical damage.
3 . The longitudinal weld of the pipe shall be near the neutral
axis of the bend.
4. Pipe shall not be bent through an arc of more than 90
degrees (1.6 rad).
5. The inside radius of a bend shall be not less than six times
the outside diameter of the pipe.
C405.3 Plastic pipe. Plastic pipe bends shall comply with the
following:
1 . The pipe shall not be damaged and the internal diameter
of the pipe shall not be effectively reduced.
2. Joints shall not be located in pipe bends.
3. The radius of the inner curve of such bends shall not be
less than 25 times the inside diameter of the pipe.
4. Where the piping manufacturer specifies the use of
special bending tools or procedures, such tools or proce-
dures shall be used.
C405.4 Elbows. Factory-made welding elbows or transverse
segments cut therefrom shall have an arc length measured
along the crotch at least 1 inch (25 mm) in pipe sizes 2 inches
(51 mm) and larger.
SECTION C406
INSPECTION, TESTING AND PURGING
C406.1 General. Prior to acceptance and initial operation, all
piping installations shall be inspected and pressure tested to
determine that the materials, design, fabrication, and installa-
tion practices comply with the requirements of this code.
C406.1.1 Inspections. Inspection shall consist of visual
examination, during or after manufacture, fabrication,
assembly, or pressure tests as appropriate. Supplementary
types of nondestructive inspection techniques, such as mag-
netic-particle, radiographic, ultrasonic, etc., shall not be
required unless specifically listed herein or in the engineer-
ing design.
C406.1.1.1 Rough piping inspection. This inspection
shall be made after piping authorized by the permit has
been installed and before such piping has been covered
or concealed or a fixture or appliance has been attached
thereto. This inspection shall include a determination
that the gas piping size, material and installation meet the
requirements of this appendix.
C406.1.1.2 Final piping inspection. This inspection
shall be made after piping authorized by the permit has
been installed and after all portions thereof which are to
be covered or concealed are so concealed and after fix-
tures, appliances or shutoff valves have been attached
thereto.
C406.1.2 Repairs and additions. In the event repairs or
additions are made after the pressure test, the affected pip-
ing shall be tested.
Minor repairs and additions are not required to be pres-
sure tested provided that the work is inspected and connec-
tions are tested with a noncorrosive leak-detecting fluid or
other approved leak-detecting methods.
C406.1.3 New branches. Where new branches are installed
to new appliances, only the newly installed branches shall
be required to be pressure tested. Connections between the
new piping and the existing piping shall be tested with a
2007 OREGON MECHANICAL SPECIALTY CODE
117.59
APPENDIX C
noncorrosive leak-detecting fluid or other approved
leak-detecting methods.
C406.1.4 SectHom testing. A piping system shall be permitted
to be tested as a complete unit or in sections. Under no cir-
cumstances shall a valve in a line be used as a bulkhead
between gas in one section of the piping system and test
medium in an adjacent section, unless two valves are installed
in series with a valved "telltale" located between these valves.
A valve shall not be subjected to the test pressure unless it can
be determined that the valve, including the valve-closing
mechanism, is designed to safely withstand the test pressure.
.1.5 Regulators aiid valve assemblies. Regulator and
valve assemblies fabricated independently of the piping
system in which they are to be installed shall be permitted to
be tested with inert gas or air at the time of fabrication.
.2 Test medium. The test medium shall be air, nitrogen,
carbon dioxide or an inert gas. Oxygen shall not be used.
€406.3 Test preparation. Pipe joints, including welds, shall
be left exposed for examination during the test.
Exceptioim: Covered or concealed pipe end joints that have
been previously tested in accordance with this appendix.
C4(06.3.1 Expansion joints. Expansion joints shall be pro-
vided with temporary restraints, if required, for the addi-
tional thrust load under test.
€406.3,2 Appliance and equipment isolation. Appliances
and equipment that are not to be included in the test shall be
either disconnected from the piping or isolated by blanks,
blind flanges, or caps. Flanged joints at which blinds are
inserted to blank off other equipment during the test shall
not be required to be tested.
€406.3.3 Appliance and equipment disconnection. Where
the piping system is connected to appliances or equipment
designed for operating pressures of less than the test pressure,
such appliances or equipment shall be isolated from the pip-
ing system by disconnecting them and capping the outlet(s).
j.3.4 Valve isolation. Where the piping system is con-
nected to appliances or equipment designed for operating
pressures equal to or greater than the test pressure, such
appliances or equipment shall be isolated from the piping
system by closing the individual appliance or equipment
shutoff valve(s).
p.3.5 Testing precautions. All testing of piping sys-
tems shall be done with due regard for the safety of employ-
ees and the public during the test. Bulkheads, anchorage,
and bracing suitably designed to resist test pressures shall be
installed if necessary. Prior to testing, the interior of the pipe
shall be cleared of all foreign material.
J.4 Test pressure measurement. Test pressure shall be
measured with a manometer or with a pressure-measuring
device designed and calibrated to read, record, or indicate a
pressure loss caused by leakage during the pressure test period.
The source of pressure shall be isolated before the pressure
tests are made. Mechanical gauges used to measure test pres-
sures shall have a range such that the highest end of the scale is
not greater than five times the test pressure.
C406.4.1 Test pressure. Gas piping systems under 14
inches (3.5 kPa) water column pressure, shall be tested at a
pressure of not less than 10 psi (69 kPa) gauge pressure. Test
pressures shall be held for not less than 15 minutes with no
perceptible drop in pressure. For welded piping, and for pip-
ing CEirrying gas at pressures exceeding 14 inches water col-
umn (3484 Pa) pressure, the test pressure shall be at least 60
psi (0.0422 kg/mm^) for not less than 30 minutes.
Exception: Testing, inspection and purging of gas pip-
ing systems performed by using NFPA 54 shall be per-
mitted.
SECTION C407
PIPING SUPPORT
C407.1 General. Piping shall be provided with support in
accordance with Section C407.2.
C407.2 Design and installation. Piping shall be supported
with pipe hooks, metal pipe straps, bands, brackets, or hangers
suitable for the size of piping, of adequate strength and quality,
and located at intervals so as to prevent or damp out excessive
vibration. Piping shall be anchored to prevent undue strains on
connected equipment and shall not be supported by other pip-
ing. Pipe hangers and supports shall conform to the require-
ments of MSS SP-58 and shall be spaced in accordance with
Section C415. Supports, hangers, and anchors shall be
installed so as not to interfere with the free expansion and con-
traction of the piping between anchors. All parts of the support-
ing equipment shall be designed and installed so they will not
be disengaged by movement of the supported piping.
SECTION C408
DRIPS AND SLOPED PIPING
C408.1 Slopes. Piping for other than dry gas conditions shall
be sloped not less than V4 inch in 15 feet (6.3 mm in 4572 mm)
to prevent traps.
C408.2 Drips. Where wet gas exists, a drip shall be provided at
any point in the line of pipe where condensate could collect. A
drip shall also be provided at the outlet of the meter and shall be
installed so as to constitute a trap wherein an accumulation of
condensate will shut off the flow of gas before the condensate
will run back into the meter.
C408,3 Location of drips. Drips shall be provided with ready
access to permit cleaning or emptying. A drip shall not be
located where the condensate is subject to freezing.
C408.4 Sediment trap. Where a sediment trap is not incorpo-
rated as part of the gas utilization equipment, a sediment trap
shall be installed downstream of the equipment shutoff valve as
close to the inlet of the equipment as practical. The sediment
trap shall be either a tee fitting with a capped nipple in the bot-
tom opening of the run of the tee or other device approved as an
effective sediment trap. Illuminating appliances, ranges,
clothes dryers and outdoor grills need not be so equipped.
<
117.60
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
SECTION C409
SHUTOFF VALVES
C409.1 General. Piping systems shall be provided with shut-
off valves in accordance with this section.
C409.1.1 Valve approval. Shutoff valves shall be of an
approved type; shall be constructed of materials compatible
with the piping; and shall comply with the standard that is
applicable for the pressure and application, in accordance
with Table C409. 1.1.
C409.1.2 Prohibited locations. Shutoff valves shall be pro-
hibited in concealed locations and furnace plenums.
C409.1.3 Access to shutoff valves. Shutoff valves shall be
located in places so as to provide access for operation and
shall be installed so as to be protected from damage.
C409.2 Meter valve. Every meter shall be equipped with a
shutoff valve located on the supply side of the meter.
C409.3 Shutoff valves for multiple-house line systems.
Where a single meter is used to supply gas to more than one
building or tenant, a separate shutoff valve shall be provided for
each building or tenant.
C409.3.1 Multiple tenant buildings. In multiple tenant
buildings, where a common piping system is installed to
supply other than one- and two-family dwellings, shutoff
valves shall be provided for each tenant. Each tenant shall
have access to the shutoff valve serving that tenant's space.
C409.3.2 Individual buildings. In a common system serv-
ing more than one building, shutoff valves shall be installed
outdoors at each building.
C409.3.3 Identification of shutoff valves. Each house line
shutoff valve shall be plainly marked with an identification
tag attached by the installer so that the piping systems sup-
plied by such valves are readily identified.
C409.4 MP Regulator valves. A listed shutoff valve shall be
installed immediately ahead of each MP regulator.
C409.5 Equipment shutoff valve. Each appliance shall be
provided with a shutoff valve separate from the appliance. The
shutoff valve shall be located in the same room as the appli-
ance, not further than 6 feet (1829 mm) from the appliance, and
shall be installed upstream from the union, connector or quick
disconnect device it serves. Such shutoff valves shall be pro-
vided with access.
Exception: Shutoff valves for vented decorative appliances
and decorative appliances for installation in vented fire-
places shall not be prohibited from being installed in an area
remote from the appliance where such valves are provided
with ready access. Such valves shall be permanently identi-
fied and shall serve no other equipment. Piping from the
shutoff valve to within 3 feet (914 mm) of the appliance con-
nection shall be sized in accordance with Section C402.
C409.5.1 Shutoff valve in fireplace. Equipment shutoff
valves located in the firebox of a fireplace shall be installed
in accordance with the appliance manufacturer's instruc-
tions.
SECTION C410
FLOW CONTROLS
C410.1 Pressure regulators. A line pressure regulator shall be
installed where the appliance is designed to operate at a lower
pressure than the supply pressure. Line gas pressure regulators
shall be listed as complying with ANSI Z21 .80. Access shall be
provided to pressure regulators. Pressure regulators shall be
protected from physical damage. Regulators installed on the
exterior of the building shall be approved for outdoor installa-
tion.
C410.2 MP regulators. MP pressure regulators shall comply
with the following:
1 . The MP regulator shall be approved and shall be suitable
for the inlet and outlet gas pressures for the application.
2. The MP regulator shall maintain a reduced outlet pres-
sure under lockup (no-flow) conditions.
3. The capacity of the MP regulator, determined by pub-
lished ratings of its manufacturer, shall be adequate to
supply the appliances served.
4. The MP pressure regulator shall be provided with access.
Where located indoors, the regulator shall be vented to
the outdoors or shall be equipped with a leak-limiting
device, in either case complying with Section C410.3.
5 . A tee fitting with one opening capped or plugged shall be
installed between the MP regulator and its upstream
shutoff valve. Such tee fitting shall be positioned to
allow connection of a pressure-measuring instrument
and to serve as a sediment trap.
TABLE C409.1.1
MANUAL GAS VALVE STANDARDS
VALVE STANDARDS
APPLIANCE SHUTOFF
VALVE APPLICATION UP
TO Vz psig PRESSURE
OTHER VALVE APPLICATIONS
UP TO Vz psig
PRESSURE
UP TO 2 psig
PRESSURE
UP TO 5 psig
PRESSURE
UP TO 125 psig
PRESSURE
ANSIZ21.15
X
CSA Requirement 3-88
X
X
X^
x"
ASMEB 16.44
X
X
x^
x"
ASMEB 16.33
X
X
X
X
X
For SI: 1 pound per square inch gauge = 6.895 kPa.
a. If labeled 2G.
b. If labeled 5G.
2007 OREGON MECHANICAL SPECIALTY CODE
117.61
APPENDIX C
6. A tee fitting with one opening capped or plugged shall be
installed not less than 10 pipe diameters downstream of
the MP regulator outlet. Such tee fitting shall be posi-
tioned to allow connection of a pressure-measuring
instrument.
C410.3 Venting of regulators. Pressure regulators that require
a vent shall be vented directly to the outdoors. The vent shall be
designed to prevent the entry of insects, water and foreign
objects.
Exception: A vent to the outdoors is not required for regula-
tors equipped with and labeled for utilization with an
approved vent-limiting device installed in accordance with
the manufacturer's instructions.
C410.3.1 Vent piping. Vent piping shall be not smaller than
the vent connection on the pressure regulating device. Vent
piping serving relief vents and combination relief and
breather vents shall be run independently to the outdoors
> and shall serve only a single device vent.
SECTION C41 1
APPLIANCE AND MANUFACTURED
HOME CONNECTIONS
C411.1 Connecting appliances. Except as required by
Section C411.1.1, appliances shall be connected to the piping
system by one of the following:
1. Rigid metallic pipe and fittings.
2. Corrugated stainless steel tubing (CSST) where installed
in accordance with the manufacturer's instructions.
3. Semirigid metallic tubing and metallic fittings. Lengths
shall not exceed 6 feet (1829 mm) and shall be located
entirely in the same room as the appliance. Semirigid
metallic tubing shall not enter a motor-operated appli-
ance through an unprotected knockout opening.
4. Listed and labeled appliance connectors in compliance
with ANSI Z21.24 and installed in accordance with the
manufacturer's installation instructions and located
entirely in the same room as the appliance.
5 . Listed and labeled quick-disconnect devices used in con-
junction with listed and labeled appliance connectors.
6. Listed and labeled convenience outlets used in conjunc-
tion with listed and labeled appliance connectors.
7. Listed and labeled appliance connectors complying with
ANSI Z21.69 and listed for use with food service equip-
ment having casters, or that is otherwise subject to move-
ment for cleaning, and other large movable equipment.
8. Listed and labeled outdoor appliance connectors in
compliance with ANSI Z21.75/CSA 6.27 and installed
in accordance with the manufacturer's installation
instructions.
C411.1.1 Commercial cooking appliances. Commercial
cooking appliances that are moved for cleaning and sanita-
tion purposes shall be connected to the piping system with
an appliance connector listed as complying with ANSI
Z21.69.
C411.1.2 Protection against damage. Connectors and
tubing shall be installed so as to be protected against physi-
cal damage.
C411.1.3 Connector installation. Appliance fuel connec-
tors shall be installed in accordance with the manufacturer's
instructions and Sections C41 1.1.3.1 through C41 1.1.3.4.
C411.1.3.1 Maximum length. Connectors shall have an
overall length not to exceed 3 feet (914 mm), except for
range and domestic clothes dryer connectors, which
shall not exceed 6 feet (1829 mm) in overall length. Mea-
surement shall be made along the centerline of the con-
nector. Only one connector shall be used for each
appliance.
Exception: Rigid metallic piping used to connect an
appliance to the piping system shall be permitted to
have a total length greater than 3 feet (914 mm), pro-
vided that the connecting pipe is sized as part of the
piping system in accordance with Section C402 and
the location of the equipment shutoff valve complies
with Section C409.5.
C411.1,3.2 Minimum size. Connectors shall have the
capacity for the total demand of the connected appliance.
L.3.3 Prohibited locations and penetrations.
Connectors shall not be concealed within, or extended
through, walls, floors, partitions, ceilings or appliance
housings.
Exception: Fireplace inserts that are factory
equipped with grommets, sleeves or other means of
protection in accordance with the listing of the appli-
ance.
C411.1.3.4 Shutoff valve. A shutoff valve not less than
the nominal size of the cormector shall be installed ahead
of the connector in accordance with Section C409.5.
C411.1,4 Movable appliances. Where appliances are
equipped with casters or are otherwise subject to periodic
movement or relocation for purposes such as routine clean-
ing and maintenance, such appliances shall be connected to
the supply system piping by means of an approved flexible
connector designed and labeled for the application. Such
flexible connectors shall be installed and protected against
physical damage in accordance with the manufacturer's
installation instructions.
SECTION C41 3
COMPRESSED NATURAL GAS
VEHICLE FUEL=DISPENS
<
SEFIED PETROLEUM GAS MOTOR
VEHICLE FUEL-DISPENSING FACILITIES
C412.1 General. Motor fuel-dispensing facilities for LP-gas
fuel shall be in accordance with the Fire Code. "^
<
JILITIES
C413.1 General. Motor fuel-dispensing faciUties for CNG
fuel shall be in accordance with the Fire Code.
117.62
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
SECTION C41 4
SUPPLEMENTAL AND STANDBY GAS SUPPLY
C414.1 Special supplementary gas. Where air, oxygen or
other special supplementary gas is. introduced into the gas pip-
ing system, an approved backflow, preventer shall be installed.
The backflow preventer shall be on the gas line to the equip-
ment or appliance supplied by the special gas and located
between the source of the special gas and the gas meter. Where
oxygen is used, installation shall be in accordance with NFPA
51.
C414.2 Interconnections for standby fuels. Where supple-
mentary gas for standby use is connected downstream from a
meter or a service regulator where a meter is not provided, a
device to prevent backflow shall be installed. A three-way
valve installed to admit the standby supply and at the same time
shut off the regular supply shall be permitted to be used for this
purpose.
SECTION C41 5
PIPING SUPPORT INTERVALS
C415.1 Interval of support. Piping shall be supported at inter-
vals not exceeding the spacing specified in Table C4 1 5 . 1 . Spac-
ing of supports for CSST shall be in accordance with the CSST
manufacturer's instructions.
TABLE C41 5.1
SUPPORT OF PIPING
STEEL PIPE,
NOMINAL SIZE
OF PIPE
(inches)
SPACING OF
SUPPORTS
(feet)
NOMINAL SIZE
OF TUBING
(SMOOTH-WALL)
(inch O.D.)
SPACING OF
SUPPORTS
(feet)
'/2
6
'I2
4
% or 1
8
% or 3/4
6
1 V4 or larger
(horizontal)
10
%orl
(Horizontal)
8
1 V4 or larger
(vertical)
Every floor
level
1 or Larger
(vertical)
Every floor
level
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
SECTION C416
FUEL-GAS EQUIPMENT AND INSTALLATIONS IN
MANUFACTURED STRUCTURE (MOBILE HOME OR
RECREATIONAL VEHICLE) PARKS
C416.1 Required gas supply. The minimum hourly volume of
gas required at each manufactured structure (mobile home or
recreational vehicle) lot outlet or any section of the manufac-
tured structures park gas-piping system shall be calculated as
shown in Table C416.1.
Required gas supply for buildings or other fuel-gas-consum-
ing appliances connected to the manufactured structure park
gas-piping system shall be calculated as provided in this
appendix.
C416.2 Mechanical protection. Customer-owned gas outlet
risers, regulators, meters, valves or other exposed equipment
shall be protected from mechanical damage. Such protection
may consist of posts, fencing or other permanent barriers.
Atmospherically controlled regulators shall be installed in
such a manner that moisture cannot enter the regulator vent and
accumulate above the diaphragm. When the regulator vent may
be obstructed by snow or ice, shields, hoods or other suitable
devices shall be provided to guard against obstruction of the
vent opening.
C416.3 Gas meters. Customer-owned meters shall be installed
in ventilated and accessible locations, not closer than 3 feet
(914 mm) to sources of ignition.
When meters are installed, they shall not depend on the gas
outlet riser for support, but shall be adequately supported by a
post or bracket placed on a firm footing, or other approved
means providing equivalent support.
C416.4 Gas piping size. The size of each section of natural gas
or LP-gas piping systems shall be determined as specified in
this appendix.
TABLE C41 6.1
MINIMUM DEMAND FACTORS FOR CALCULATING GAS PIPING
SYSTEMS IN MANUFACTURED STRUCTURE PARKS
NUMBER OF
MANUFACTURED
STRUCTURE LOTS
DEMAND FACTOR BTU/H
MANUFACTURED STRUCTURE
LOT X 0.293 071 FOR W
1
250,000
2
234,000
3
208,000
4
198,000
5
184,000
6
174,000
7
166,000
8
162,000
9
158,000
10
154,000
11-20
132,000
21-30
124,000
31-40
118,000
41-60
112,000
Over 60
102,000
For SI: 1 Btu/h = 0.2931 W.
SECTION C41 7
OVERPRESSURE PROTECTION DEVICES
C417.1 General. Oyerpressure protection devices shall be pro-
vided in accordance with this section to prevent the pressure in
the piping system from exceeding the pressure that would
cause unsafe operation of any connected and properly adjusted
appliances.
C417.2 Protection methods.The requirements of this section
shall be considered to be met and a piping system deemed to
have overpressure protection where a service or line pressure
regulator plus one other device are installed such that the fol-
lowing occur:
1. Each device limits the pressure to a value that does not
■ exceed the maximum working pressure of the down-
stream system.
2007 OREGON MECHANICAL SPECIALTY CODE
117.63
APPENDIX C
2. The individual failure of either device does not result in
s^ the overpressurization of the downstream system.
C4173 Where required. A pressure-relieving or pres-
sure-limiting device shall not be required where: (1) the gas
does not contain materials that could seriously interfere with
the operation of the service or line pressure regulator; (2) the
operating pressure of the gas source is 60 psi (414 kPa) or less;
and (3) the service or line pressure regulator has all of the fol-
lowing design features or characteristics:
1 . Pipe connections to the service or hne regulator do not
exceed 2 inches (5 1 mm) nominal diameter.
2. The regulator is self-contained with no external static or
control piping.
3. The regulator has a single port valve with an orifice
diameter not greater than that recommended by the man-
ufacturer for the maximum gas pressure at the regulator
inlet.
4. The valve seat is made of resilient material designed to
withstand abrasion of the gas, impurities in the gas and
cutting by the valve, and to resist permanent deformation
where it is pressed against the valve port.
5. The regulator is capable, under normal operating condi-
tions, of regulating the downstream pressure within the
necessary limits of accuracy and of limiting the dis-
charge pressure under no-flow conditions to not more
than 150 percent of the discharge pressure maintained
under flow conditions.
C417.4 DeviceSo Pressure-relieving or pressure-limiting
devices shall be one of the following:
1 . Spring-loaded relief device.
2. Pilot-loaded back pressure regulator used as a relief
valve and designed so that failure of the pilot system or
external control piping will cause the regulator relief
valve to open.
3. A monitoring regulator installed in series with the ser-
vice or line pressure regulator.
4. A series regulator installed upstream from the service or
line regulator and set to continuously limit the pressure
on the inlet of the service or line regulator to the maxi-
mum working pressure of the downstream piping sys-
tem.
5. An automatic shutoff device installed in series with the
service or line pressure regulator and set to shut off when
the pressure on the downstream piping system reaches
the maximum working pressure or some other predeter-
mined pressure less than the maximum working pres-
sure. This device shall be designed so that it will remain
closed until manually reset.
6. A liquid seal relief device that can be set to open accu-
rately and consistently at the desired pressure.
The devices shall be installed either as an integral part of the
service or line pressure regulator or as separate units. Where
separate pressure-relieving or pressure-limiting devices are
installed, they shall comply with Sections C417.4.1 through
C417.4.5.
C417o4.1 Construction and installation. Pressure rehev-
ing and pressure-limiting devices shall be constructed of
materials so that the operation of the devices will not be
impaired by corrosion of external parts by the atmosphere or
of internal parts by the gas. Pressure-relieving and pres-
sure-limiting devices shall be designed and installed so that
they can be operated to determine whether the valve is free.
The devices shall also be designed and installed so that they
can be tested to determine the pressure at which they will
operate and examined for leakage when in the closed posi-
tion.
C417.4.2 External control piping. External control piping
shall be protected from falling objects, excavations and
other causes of damage and shall be designed and installed
so that damage to any control piping will not render both the
regulator and the overpressure protective device inopera-
tive.
C417.4.3 Setting. Each pressure-relieving or pressure-lim-
iting device shall be set so that the pressure does not exceed
a safe level beyond the maximum allowable working pres-
sure for the connected piping and appliances. ^
C417.4.4 Vents. The discharge stacks, vents and outlet parts
of all pressure-relieving and pressure-limiting devices shall
be located so that gas is safely discharged to the outdoors.
Discharge stacks and vents shall be designed to prevent the
entry of water, insects and other foreign material that could
cause blockage. The discharge stack or vent line shall be at
least the same size as the outlet of the pressure-relieving
device.
C417.4.5 Size of fittings, pipe and openings. The fittings,
pipe and openings located between the system to be pro-
tected and the pressure-relieving device shall be sized to
prevent hammering of the valve and to prevent impairment
of relief capacity.
SECTION C501
GENERAL
C501.1 Scope. This appendix shall govern the installation, <;
repair and approval of factory -built chimneys, chimney liners,
vents and connectors and the utilization of masonry chimneys
serving gas-fired appliances. The requirements for the installa-
tion, repair and approval of factory-built chimneys, chimney <^
liners, vents and connectors serving appliances burning fuels
other than fuel gas shall be regulated by this code. The con-
struction, repair, and approval of masonry chimneys shall be
regulated by the Building Code.
C501.2 General. Every apphance shall discharge the products
of combustion to the outdoors, except for appliances exempted
by Section C501.8.
C501.3 Masonry chimneys. Masonry chimneys shall be con-
structed in accordance with the Building Code. ^
C501.4 Minimum size of chimney or vent. Chimneys and
vents shall be sized in accordance with Section C504.
C501.5 Abandoned inlet openings. Abandoned inlet open-
ings in chimneys and vents shall be closed by an approved
method.
117.64
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
II
C501.6 Positive pressure. Where an appliance equipped with
a mechanical forced draft system creates a positive pressure in
the venting system, the venting system shall be designed for
positive pressure applications.
C501.7 Connection to fireplace. Connection of appliances to
chimney flues serving fireplaces shall be in accordance with
Sections C501.7.1 through C501.7.3.
C501.7.1 Closure and access. A noncombustible seal shall
be provided below the point of connection to prevent entry
of room air into the flue. Means shall be provided for access
to the flue for inspection and cleaning.
C501.7.2 Connection to factory-built fireplace flue. An
appliance shall not be connected to a flue serving a fac-
tory-built fireplace unless the appliance is specifically listed
for such installation. The connection shall be made in accor-
dance with the appliance manufacturer's installation
instructions.
C501.7.3 Connection to masonry fireplace flue. A con-
nector shall extend from the appliance to the flue serving a
masonry fireplace such that the flue gases are exhausted
directly into the flue. The connector shall be accessible or
removable for inspection and cleaning of both the connector
and the flue. Listed direct connection devices shall be
installed in accordance with their listing.
C501.8 Equipment not required to be vented. The following
appliances shall not be required to be vented.
1. Ranges.
2. Built-in domestic cooking units listed and marked for
optional venting.
3. Hot plates and laundry stoves.
4. Type 1 clothes dryers (Type 1 clothes dryers shall be
exhausted in accordance with the requirements of
Chapter 5, Section 504.4).
5. A single booster-type automatic instantaneous water
heater, where designed and used solely for the sanitiz-
ing rinse requirements of a dishwashing machine, pro-
vided that the heater is installed in a commercial
kitchen having a mechanical exhaust system. Where
installed in this manner, the draft hood, if required,
shall be in place and unaltered and the draft hood outlet
shall be not less than 36 inches (914 mm) vertically and
6 inches (152 mm) horizontally from any surface other
than the heater.
6. Refrigerators.
7. Counter appliances.
8. Room heaters listed for unvented use.
9. Direct-fired make-up air heaters.
10. Other equipment listed for unvented use and not pro-
vided with flue collars.
1 1 . Specialized equipment of limited input such as labora-
tory burners and gas lights.
Where the appliances and equipment listed in Items 5 through
1 1 above are installed so that the aggregate input rating exceeds
20 British thermal units (Btu) per hour per cubic feet (207 watts
per m^) of volume of the room or space in which such appliances
and equipment are installed, one or more shall be provided with
venting systems or other approved means for conveying the vent
gases to the outdoor atmosphere so that the aggregate input rat-
ing of the remaining unvented appliances and equipment does
not exceed the 20 Btu per hour per cubic foot (207 watts per m^)
figure. Where the room or space in which the equipment is
installed is directly connected to another room or space by a
doorway, archway, or other opening of comparable size that can-
not be closed, the volume of such adjacent room or space shall be
permitted to be included in the calculations.
C501.9 Chimney entrance. Connectors shall connect to a
masonry chimney flue at a point not less than 12 inches (305
mm) above the lowest portion of the interior of the chimney flue.
C501.10 Connections to exhauster. Apphance connections to
a chimney or vent equipped with a power exhauster shall be
made on the inlet side of the exhauster. Joints on the positive
pressure side of the exhauster shall be sealed to prevent
flue-gas leakage as specified by the manufacturer's installation
instructions for the exhauster.
C501.ll Masonry chimneys. Masonry chimneys utilized to
vent appliances shall be sized as specified in the manufacturer ' s <^
installation instructions for the appliances being vented and
Section C503.
C501.12 Residential and low-heat appliances flue lining
systems. Flue lining systems for use with residential-type and
low-heat appliances shall be limited to the following:
1. Clay flue lining complying with the requirements of
ASTM C 315 or equivalent. Clay flue lining shall be
installed in accordance with the Building Code.
2. Listed chimney lining systems complying with UL 1777.
3. Other approved materials that will resist, without crack-
ing, softening or corrosion, flue gases and condensate at
temperatures up to 1,800T (982°C).
C501.13 Category I appliance flue lining systems. Flue lin-
ing systems for use with Category I appliances shall be limited
to the following:
1. Flue lining systems complying with Section C501.12.
2. Chimney lining systems listed and labeled for use with
gas appliances with draft hoods and other Category I gas
appliances listed and labeled for use with Type B vents.
C501.14 Category 11, III and IV appliance venting systems.
The design, sizing and installation of vents for Category II, III
and IV appliances shall be in accordance with the appliance
manufacturer's installation instructions.
C501.15 Existing chimneys and vents. Where an appliance is
permanently disconnected from an existing chimney or vent, or
where an appliance is connected to an existing chimney or vent
during the process of a new installation, the chimney or vent
shall comply with Sections C501.15.1 through C501.15.4.
C501.15.1 Size. The chimney or vent shall be resized as nec-
essary to control flue gas condensation in the interior of the
chimney or vent and to provide the appliance or appUances
served with the required draft. For Category I appliances, the
resizing shall be in accordance with Section C502.
2007 OREGON MECHANICAL SPECIALTY CODE
117.65
APPENDIX C
C5®1.15,2 Flue passageways. The flue gas passageway
shall be free of obstructions and combustible deposits and
shall be cleaned if previously used for venting a solid or liq-
uid fuel-burning appliance or fireplace. The flue liner, chim-
ney inner wall or vent inner wall shall be continuous and
shall be free of cracks, gaps, perforations or other damage or
deterioration which would allow the escape of combustion
products, including gases, moisture and creosote.
CSOl.15.3 Cleaeout. Masonry chimney flues shall be pro-
vided with a cleanout opening having a minimum height of
6 inches (152 mm). The upper edge of the opening shall be
located not less than 6 inches (152 mm) below the lowest
chimney inlet opening. The cleanout shall be provided with
a tight-fitting, noncombustible cover.
C5©1.15.4 Clearances. Chimneys and vents shall have air-
space clearance to combustibles in accordance with the Build-
ing Code and the chimney or vent manufacturer's installation
instructions. Noncombustible firestopping or fireblocking
shall be provided in accordance with the Building Code.
Exception; Masonry chimneys equipped with a chim-
ney lining system tested and listed for installation in
chimneys in contact with combustibles in accordance
with UL 1777, and installed in accordance with the man-
ufacturer's instructions, shall not be required to have
clearance between combustible materials and exterior
surfaces of the masonry chimney.
SECTION C502
VENTS
C502.1 GeeeraL All vents, except as provided in Section
C503.7, shall be listed and labeled. Type B and BW vents shall
be tested in accordance with UL 441. Type L vents shall be
tested in accordance with UL 641. Vents for Category II and III
appliances shall be tested in accordance with UL 1738. Plastic
vents for Category IV appliances shall not be required to be
listed and labeled where such vents are as specified by the
appliance manufacturer and are installed in accordance with
the appliance manufacturer's installation instructions.
C502.2 Connectors required. Connectors shall be used to
connect appliances to the vertical chimney or vent, except
where the chimney or vent is attached directly to the appliance.
Vent connector size, material, construction and installation
shall be in accordance with Section C503.
C502.3 Vent application. The application of vents shall be in
accordance with Table C503.4.
CS02.4 Insulation shield. Where vents pass through insulated
assemblies, an insulation shield constructed of not less than 26
gage sheet (0,016 inch) (0.4 mm) metal shall be installed to pro-
vide clearance between the vent and the insulation material. The
clearance shall not be less than the clearance to combustibles
specified by the vent manufacturer's installation instructions.
Where vents pass through attic space, the shield shall terminate
not less than 2 inches (5 1 mm) above the insulation materials and
shall be secured in place to prevent displacement. Insulation
shields provided as part of a listed vent system shall be installed
in accordance with the manufacturer's installation instructions.
C502.5 Installation. Vent systems shall be sized, installed and
terminated in accordance with the vent and appliance manufac-
turer's installation instructions and Section C503.
C502.6 Support of vents. All portions of vents shall be ade-
quately supported for the design and weight of the materials
employed.
C502.7 Protection against physical damage. In concealed
locations, where a vent is installed through holes or notches in
studs, joists, rafters or similar members less than 1.5 inches (38
mm) from the nearest edge of the member, the vent shall be pro-
tected by shield plates in accordance with Section 305.5.
SECTION C503
VENTING OF APPLIANCES
C503.1 General. This section recognizes that the choice of
venting materials and the methods of installation of venting
systems are dependent on the operating characteristics of the
appliance being vented. The operating characteristics of vented
appliances can be categorized with respect to: (1) positive or
negative pressure within the venting system; and (2) whether or
not the appliance generates flue or vent gases that might con-
dense in the venting system. See Section C202 for the defini-
tions of these vented appliance categories.
C503.2 Venting systems required. Except as permitted in
Sections C503.2.1 through C503.2.4 and C501.8, all appli-
ances shall be connected to venting systems.
C503.2.1 Ventilating hoods. Ventilating hoods and exhaust
systems shall be permitted to be used to vent appliances
installed in commercial applications (see Section C503.3.4)
and to vent industrial appliances, such as where the process
itself requires fume disposal.
C503.2.2 Well-ventilated spaces. Where located in a large
and well-ventilated space, industrial appliances shall be
permitted to be operated by discharging the flue gases
directly into the space.
C503.2.3 Direct-vent appliances. Listed direct- vent apph-
ances shall be installed in accordance with the manufac-
turer's instructions and Section C503.8, Item 3.
C503.2.4 Appliances with integral vents. Appliances incor-
porating integral venting means shall be considered properly
vented where installed in accordance with the manufacturer's
instructions and Section C503.8, Items 1 and 2.
C503.3 Design and construction. A venting system shall be
designed and constructed so as to develop a positive flow
adequate to convey flue or vent gases to the outdoors.
C503.3.1 Appliance draft requirements. A venting sys-
tem shall satisfy the draft requirements of the appliance in
accordance with the manufacturer's instructions.
C503,3.2 Design and construction. Appliances required to
be vented shall be connected to a venting system designed
and installed in accordance with the provisions of Sections
C503.4 through C503. 15.
C503.3.3 Mechanical draft systems. Mechanical draft
systems shall comply with the following:
<
117.66
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
1. Mechanical draft systems shall be hsted and shall be
installed in accordance with the manufacturer's
installation instructions for both the appliance and the
mechanical draft system.
2. Appliances, except incinerators, requiring venting
shall be permitted to be vented by means of mechani-
cal draft systems of either forced or induced draft
design.
3. Forced draft systems and all portions of induced draft
systems under positive pressure during operation
shall be designed and installed so as to prevent leak-
age of flue or vent gases into a building.
4. Vent connectors serving appUances vented by natural
draft shall not be connected into any portion of mechani-
cal draft systems operating tinder positive pressure.
5. Where a mechanical draft system is employed, provi-
sions shall be made to prevent the flow of gas to the
main burners when the draft system is not performing
so as to satisfy the operating requirements of the
appliance for safe performance.
6. The exit terminals of mechanical draft systems shall
be not less than 7 feet (2134 mm) above grade where
located adjacent to public walkways and shall be
located as specified in Section C503.8, Items 1 and 2.
C503.3.4 Ventilating hoods and exhaust systems. Ventilat-
ing hoods and exhaust systems shall be permitted to be used
tO;, vent appliances installed in commercial applications.
Where automatically operated appliances are vented through
a ventilating hood or exhaust system equipped with a damper
or with a power means of exhaust, provisions shall be made to
allow the flow of gas to the main burners only when the
damper is open to a position to properly vent the appliance
and when the power means of exhaust is in operation.
Exception: The interlock between a commercial cooking
apphance and its exhaust hood system shall not be required
for manually operated appliances that are factory equipped
with a standing pilot burner ignition system. Type I and
Type II commercial cooking exhaust hoods shall be
designed and installed in accordance with Section 507.
C503.3.5 Circulating air ducts and furnace plenums. No
portion of a venting system shall extend into or pass through
any circulating air duct or furnace plenum.
TABLE C503.4
TYPE OF VENTING SYSTEM TO BE USED
APPLIANCES
TYPE OF VENTING SYSTEM
Listed Category I appliances
Listed appliances equipped with draft hood
Appliances listed for use with Type B gas vent
Type B gas vent (Section C503.6)
Chimney (Section C503.5)
Single-wall metal pipe (Section C503.7)
Listed chimney lining system for gas venting (Section C503.5.3)
Special gas vent listed for these appliances (Section C503.4.2)
Listed vented wall furnaces
Type B-W gas vent (Sections C503.6, C608)
Category II appliances
As specified or fumishedby manufacturers of listed appliances (Sections
C503.4.1,C503.4.2)
Category III appliances
As specified or furnished by manufacturers of listed appliances (Sections
C503.4.1,C503.4.2)
Category IV appliances
As specified or furnished by manufacturers of listed appliances (Sections
C503.4.1,C503.4.2)
Incinerators, indoors
Chimney (Section C503.5)
Incinerators, outdoors
Single-wall metal pipe (Sections C503.7, C503.7.6)
Appliances that can be converted for use with solid fuel
Chimney (Section C503.5)
Unlisted combination gas and oil-burning appliances
Chimney (Section C503.5)
Listed combination gas and oil-burning appliances
Type L vent (Section C503.6) or chimney (Section C503.5)
Combination gas and solid fuel-burning appliances
Chimney (Section C503.5)
Appliances listed for use with chimneys only
Chimney (Section C503.5)
Unlisted appliances
Chimney (Section C503.5)
Decorative appliances in vented fireplaces
Chimney
Gas-fired toilets
Single-wall metal pipe (Section C626)
Direct-vent appliances
See Section C503.2.3
Appliances with integral vent
See Section C503.2.4
2007 OREGON MECHANICAL SPECIALTY CODE
117.67
APPENDIX C
C5033.6 Above-ceilmg air-handfling spaces. Where a
venting system passes through an above-ceiling air-han-
dling space or other nonducted portion of an air-handling
system, the venting system shall conform to one of the fol-
lowing requirements:
1 . The venting system shall be a listed special gas vent;
other venting system serving a Category III or Cate-
gory IV appliance; or other positive pressure vent,
with joints sealed in accordance with the appliance or
vent manufacturer's instructions.
2. The venting system shall be installed such that fittings
and joints between sections are not installed in the
above-ceiling space.
3. The venting system shall be installed in a conduit or
enclosure with sealed joints separating the interior of
the conduit or enclosure from the ceiling space.
C5©3.4 Type of veeting system to be used. The type of vent-
ing system to be used shall be in accordance with Table C503.4.
C5®3.4.1 Plastic piping. Plastic piping used for venting
appliances listed for use with such venting materials shall be
approved.
C503.4.2 Special gas vent. Special gas vent shall be listed
and installed in accordance with the special gas vent
manufacturer's installation instructions.
C503.5 Masonry, metal, and factory-built chimneys.
Masonry, metal and factory-built chimneys shall comply with
Sections C503.5.1 through C503.5.10.
C503.5.1 Factory-built chimneys. Factory-built chimneys
shall be installed in accordance with the manufacturer's
installation instructions. Factory-built chimneys used to
vent appliances that operate at a positive vent pressure shall
be listed for such application.
C503.5.2 Metal chimneys. Metal chimneys shall be built
and installed in accordance with NFPA 211.
C503.5.3 Masonry chimneys. Masonry chimneys shall be
built and installed in accordance with the Building Code
and shall be lined with approved clay flue lining, a listed
chimney lining system or other approved material that will
resist corrosion, erosion, softening or cracking from vent
gases at temperatures up to 1,800°F (982°C).
Exception: Masonry chimney flues serving listed gas
appliances with draft hoods. Category I appliances and
other gas appliances listed for use with Type B vents shall
be permitted to be lined with a chimney lining system
specifically listed for use only with such appliances. The
liner shall be installed in accordance with the hner manu-
facturer's installation instructions. A permanent identi-
fying label shall be attached at the point where the
connection is to be made to the liner. The label shall read:
"This chimney liner is for appliances that bum gas only.
Do not connect to solid or liquid fuel-burning appliances
or incinerators."
For installation of gas vents in existing masonry chim-
neys, see Section C503.6.3.
C503.5.4 Chimney termination. Chimneys for residen-
tial-type or low-heat appliances shall extend at least 3 feet
(914 mm) above the highest point where they pass through a
roof of a building and at least 2 feet (610 mm) higher than
any portion of a building within a horizontal distance of 10
feet (3048 mm) (see Figure C503.5.4). Chimneys for
medium-heat appliances shall extend at least 10 feet (3048
mm) higher than any portion of any building within 25 feet
(7620 mm). Chimneys shall extend at least 5 feet (1524 mm)
above the highest connected appliance draft hood outlet or
flue collar. Decorative shrouds shall not be installed at the
termination of factory-built chimneys except where such
shrouds are listed and labeled for use with the specific fac-
tory-built chimney system and are installed in accordance
with the manufacturer's installation instructions.
C503.5.5 Size of chimneys. The effective area of a chimney
venting system serving listed appliances with draft hoods.
Category I appliances, and other appliances listed for use
with Type B vents shall be determined in accordance with
one of the following methods:
1. The provisions of Section C504.
2. For sizing an individual chimney venting system for a
single appliance with a draft hood, the effective areas
of the vent connector and chimney flue shall be not
less than the area of the appliance flue collar or draft
hood outlet, nor greater than seven times the draft
hood outlet area.
3. For sizing a chimney venting system connected to
two appliances with draft hoods, the effective area of
the chimney flue shall be not less than the area of the
larger draft hood outlet plus 50 peicent of the area of
the smaller draft hood outlet, nor greater than seven
times the smallest draft hood outlet area.
4. Chimney venting systems using mechanical draft
shall be sized in accordance with approved engineer-
ing methods.
5. Other approved engineering methods.
C503.S.5.1 Incinerator venting. Where an incinerator
is vented by a chimney serving other appliances, the gas
input to the incinerator shall not be included in calculat-
ing chimney size, provided that the chimney flue diame-
ter is not less than 1 inch (25 nmii) larger in equivalent
diameter than the diameter of the incinerator flue outlet.
C503.5.6 Inspection of chimneys. Before replacing an
existing appliance or connecting a vent connector to a chim-
ney, the chimney passageway shall be examined to ascertain
that it is clear and free of obstructions and it shall be cleaned
if previously used for venting solid or liquid fuel-burning
appliances or fireplaces.
C503.5.6.1 Chimney lining. Chimneys shall be lined in
accordance with NFPA 211.
Exception: Existing chimneys shall be permitted to
have their use continued when an appliance is
replaced by an appliance of similar type, input rating,
and efficiency. '^
117.68
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
10 FT
OR LESS
CHIMNEY
WALL OR
PARAPET
3 FT
MIN
CHIMNEY
1^
CHIMNEY
A. TERMINATION 10 FT OR LESS FROM RIDGE, WALL, OR PARAPET
NOTE: NO HEIGHT
ABOVE PARAPET
REQUIRED WHEN
DISTANCE FROM WALLS
OR PARAPET IS MORE CHIMNEY
THAN 10 FT
HEIGHT ABOVE
ANY ROOF
SURFACE WITHIN
10 FT HORIZONTALLY
CHIMNEY
B. TERMINATION MORE THAN 10 FT FROM RIDGE, WALL, OR PARAPET
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
FIGURE C503.5.4
TYPICAL TERMINATION LOCATIONS FOR
CHIMNEYS AND SINGLE-WALL METAL PIPES SERVING
RESIDENTIAL-TYPE AND LOW-HEAT EQUIPMENT
C503.5.6.2 Unsafe chimneys. Where inspection reveals
that an existing chimney is not safe for the intended
application, it shall be repaired, rebuilt, lined, relined or
replaced with a vent or chimney to conform to the build-
ing code or this code and it shall be suitable for the appli-
ances to be vented.
C503.5.7 Chimneys serving equipment burning other
fuels. Chimneys serving equipment burning other fuels
shall comply with Sections C503.5.7.1 through C503.5.7.4.
C503.5.7.1 Solid fuel-burning appliances. An
appliance shall not be connected to a chimney flue serv-
ing a separate appliance designed to bum sohd fuel.
C503.5.7.2 Liquid fuel-burning appliances. Where
one chimney flue serves gas appliances and liquid
fuel-burning appliances, the appliances shall be con-
nected through separate openings or shall be connected
through a single opening where joined by a suitable fit-
ting located as close as practical to the chimney. Where
two or more openings are provided into one chimney
flue, they shall be at different levels. Where the appli-
ances are automatically controlled, they shall be
equipped with safety shutoff devices.
C503.5.7.3 Combination gas and solid fuel-burning
appliances. A combination gas- and solid fuel-burning
appliance shall be permitted to be connected to a single
chimney flue where equipped with a manual reset device
to shut off gas to the main burner in the event of sustained
backdraft or flue gas spillage. The chimney flue shall be
sized to properly vent the appliance.
C503.5.7.4 Combination gas- and oil fuel-burning
appliances. A listed combination gas- and oil fuel-burn-
ing appliance shall be permitted to be connected to a sin-
gle chimney flue. The chimney flue shall be sized to
properly vent the appliance.
C503.5.8 Support of chimneys. All portions of chimneys
shall be supported for the design and weight of the materials
employed. Factory-built chimneys shall be supported and
spaced in accordance with the manufacturer's installation
instructions.
C503.5.9 Cleanouts. Where a chimney that formerly car-
ried flue products from liquid or solid fuel-burning appli-
ances is used with an appliance using fuel gas, an accessible
cleanout shall be provided. The cleanout shall have a
tight-fitting cover and shall be installed so its upper edge is
at least 6 inches (152 mm) below the lower edge of the low-
est chimney inlet opening.
C503.5.10 Space surrounding lining or vent. The remain-
ing space surrounding a chimney liner, gas vent, special gas
vent or plastic piping installed within a masonry chimney
flue shall not be used to vent another appliance. The inser-
tion of another liner or vent within the chimney as provided
in this code and the liner or vent manufacturer's instructions
shall not be prohibited.
The remaining space surrounding a chimney Uner, gas vent,
special gas vent or plastic piping installed within a masonry,
metal or factory-built chimney shall not be used to supply com-
2007 OREGON MECHANICAL SPECIALTY CODE
117.69
APPENDIX C
bustion air. Such space shall not be prohibited from supplying
combustion air to direct- vent appliances designed for installa-
tion in a solid fuel-burning fireplace and installed in accor-
dance with the manufacturer's installation instructions.
C503o6 Gas vents. Gas vents shall comply with Sections
C503.6.1 through C503.6.12 (see Section C202, Definitions).
C503.6.1 Installation, general. Gas vents shall be installed
in accordance with the manufacturer's installation instruc-
tions.
C503.6.2 Type B-W vent capacity. A Type B-W gas vent
shall have a listed capacity not less than that of the listed
vented wall furnace to which it is connected.
C503.6.3 Gas vents installed within masonry chimneys.
Gas vents installed within masonry chimneys shall be
installed in accordance with the manufacturer's installation
instructions. Gas vents installed within masonry chimneys
shall be identified with a permanent label installed at the
point where the vent enters the chimney. The label shall con-
tain the following language: "This gas vent is for appliances
that bum gas. Do not connect to solid or liquid fuel-burning
appliances or incinerators."
C503.6.4 Gas vent terminations. A gas vent shall termi-
nate in accordance with one of the following:
1. Gas vents that are 12 inches (305 mm) or less in size
and located not less than 8 feet (2438 mm) from a ver-
tical wall or similar obstruction shall terminate above
the roof in accordance with Figure C503.6.4.
2. Gas vents that are over 12 inches (305 mm) in size or
are located less than 8 feet (2438 mm) from a vertical
wall or similar obstruction shall terminate not less
than 2 feet (610 mm) above the highest point where
they pass through the roof and not less than 2 feet (610
mm) above any portion of a building within 10 feet
(3048 mm) horizontally.
3. As provided for industrial appliances in Section
C503.2.2.
4. As provided for direct-vent systems in Section
C503.2.3.
5. As provided for appliances with integral vents in Sec-
tion C503.2.4.
6. As provided for mechanical draft systems in Section
C503.3.3.
7. As provided for ventilating hoods and exhaust sys-
tems in Section C503.3.4.
C503.6.4.1 Decorative shrouds. Decorative shrouds
shall not be installed at the termination of gas vents
except where such shrouds are listed for use with the spe-
cific gas venting system and are installed in accordance
with manufacturer's installation instructions.
C503.6.5 Minimum height. A Type B or L gas vent shall
terminate at least 5 feet (1524 mm) in vertical height above
the highest connected appliance draft hood or flue collar. A
Type B-W gas vent shall terminate at least 12 feet (3658
mm) in vertical height above the bottom of the wall furnace.
H(MIN.)-
MINIMUM HEIGHT FROM ROOF
TO LOWEST DISCHAflGE OPENING
ROOF SLOPE
H (min) ft
Flat to 6/12
1.0
Over 6/12 to 7/12
1.25
Over 7/12 to 8/12
1.5
Over 8/12 to 9/12
2.0
Over 9/12 to 10/12
2.5
Over 10/12 to 11/12
3.25
Over 11/12 to 12/12
4.0
Over 12/12 to 14/12
5.0
Over 14/12 to 16/12
6.0
Over 16/12 to 18/12
7.0
Over 18/12 to 20/12
7.5
Over 20/12 to 21/12
8.0
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
FIGURE C503.6.4
TERMINATION LOCATIONS FOR GAS VENTS WITH
LISTED CAPS 12 INCHES OR LESS IN SIZE AT LEAST 8 FEET
C503.6.6 Roof terminations. Gas vents shall extend
through the roof flashing, roof jack or roof thimble and ter-
minate with a listed cap or listed roof assembly.
C503.6.7 Forced air inlets. Gas vents shall terminate not
less than 3 feet (914 mm) above any forced air inlet located
within 10 feet (3048 mm).
C503.6.8 Exterior wall penetrations. A gas vent extend-
ing through an exterior wall shall not terminate adjacent to
the wall or below eaves or parapets, except as provided in
Sections C503.2.3 and C503.3.3.
C503.6.9 Size of gas vents. Venting systems shall be sized
and constructed in accordance with Section C504 or other
approved engineering methods and the gas vent and appli-
ance manufacturer's installation instructions.
C503.6.9.1 Category I appliances. The sizing of natu-
ral draft venting systems serving one or more listed
appliances equipped with a draft hood or appliances
listed for use with Type B gas vent, installed in a single
117.70
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
Story of a building, shall be in accordance with one of the
following methods:
1. The provisions of Section C504.
2. For sizing an individual gas vent for a single,
draft-hood-equipped appUance, the effective area of
the vent connector and the gas vent shall be not less
than the area of the appUance draft hood outlet, nor
greater than seven times the draft hood outlet area.
3. For sizing a gas vent Connected to two appliances
with draft hoods, the effective area of the vent shall
be not less than the area of the larger draft hood
outlet plus 50 percent of the area of the smaller
draft hood outlet, nor greater than seven times the
smaller draft hood outlet area.
4. Approved engineering practices.
C503.6.9.2 Vent offsets. Type B and L vents sized in
accordance with Item 2 or 3 of Section C503.6.9.1 shall
extend in a generally vertical direction with offsets not
exceeding 45 degrees (0.79 rad), except that a vent system
having not more than one 60-degree ( 1 .04 rad) offset shall
be permitted. Any angle greater than 45 degrees (0.79 rad)
from the vertical is considered horizontal. The total hori-
zontal distance of a vent plus the horizontal vent connector
serving draft hood-equipped appliances shall be not
greater than 75 percent of the vertical height of the vent.
C503.6.9.3 Category II, III and IV appliances. The
sizing of gas vents for Category II, III and IV appliances
shall be in accordance with the appliance manufacturer's
instructions.
C503.6,9.4 Mechanical draft. Chimney venting sys-.
tems using mechanical draft shall be sized in accordance
with approved engineering methods.
C503.6.10 Gas vents serving appliances on more than one
floor. A common gas vent shall be permitted in multistory
installations to vent Category I appliances located on more
than one floor level, provided that the venting system is
designed and installed in accordance with approved engineer-
ing methods. For the purpose of this section, crawl spaces,
basements and attics shall be considered as floor levels.
C503.6.10.1 Appliance separation. All appliances con-
nected to the common vent shall be located in rooms sep-
arated from occupiable space. Each of these rooms shall
have provisions for an adequate supply of combustion,
ventilation and dilution air that is not supplied from an
occupiable space (see Figure C503.6.10.1).
C503.6.10.2 Sizing. The size of the connectors and com-
mon segments of multistory venting systems for
appliances listed for use with Type B double-wall gas
vents shall be in accordance with Table C504.3(l)and
Figures C-B- 13 and C-B-14 in Appendix C-B, provided:
1 . The available total height {H) for each segment of a
multistory venting system is the vertical distance
between the level of the highest draft hood outlet or
flue collar on that floor and the centerline of the next
highest interconnection tee (see Figure C-B- 13).
GAS FURNACE
TYPE B GAS VENTS
AIR GRILLS IN
OUTSIDE WALL
LOUVERED DOOR PERMITTED
TO BE USED IN LIEU OF
OUTSIDE WALL GRILLS
FIGURE C503.6.1 0.1
PLAN VIEW OF PRACTICAL SEPARATION METHOD
FOR MULTISTORY GAS VENTING
2. The size of the connector for a segment is
determined from the appliance input rating and
available connector rise, and shall not be smaller
than the draft hood outlet or flue collar size.
3. The size of the common vertical segment, and of
the interconnection tee at the base of that segment,
shall be based on the total appliance input rating
entering that segment and its available total height.
C503.6.11 Support of gas vents. Gas vents shall be
supported and spaced in accordance with the manufac-
turer's installation instructions.
C503.6.12 Marking. In those localities where solid and liq-
uid fuels are used extensively, gas vents shall be perma-
nently identified by a label attached to the wall or ceiling at a
point where the vent connector enters the gas vent. The
determination of where such localities exist shall be made
by the code official. The label shall read:
"This gas vent is for appliances that burn gas.
Do not connect to solid or liquid fuel-burning
apphances or incinerators."
C503.7 Single-wall metal pipe. Single-wall metal pipe vents
shall comply with Sections C503.7.1 through C503.7.12.
C503.7.1 Construction. Single-wall metal pipe shall be
constructed of galvanized sheet steel not less than 0.0304
inch (0.7 mm) thick, or other approved, noncombustible,
corrosion-resistant material.
C503.7.2 Cold climate. Uninsulated single-wall metal pipe
shall not be used outdoors for venting appliances in regions
where the 99-percent winter design temperature is below
32T (0°C).
C503.7.3 Termination. Single-wall metal pipe shall termi-
nate at least 5 feet (1524 mm) in vertical height above the
highest connected appliance draft hood outlet or flue collar.
Single- wall metal pipe shall extend at least 2 feet (610 mm)
above the highest point where it passes through a roof of a
building and at least 2 feet (610 mm) higher than any portion
2007 OREGON MECHANICAL SPECIALTY CODE
117.71
APPENDIX C
of a building within a horizontal distance of 10 feet (3048
mm) (see Figure C503.5.4). An approved cap or roof assem-
bly shall be attached to the terminus of a single-wall metal
pipe (see also Section C503.7.8, Item 3).
CS(0)3,7.4 Limitations of esco Single-wall metal pipe shall
be used only for runs directly from the space in which the
appliance is located through the roof or exterior wall to the
outdoor atmosphere.
CSiDi3.7J Moof pemetrations. A pipe passing through a roof
shall extend without interruption through the roof flashing,
roof jack, or roof thimble. Where a single-wall metal pipe
passes through a roof constructed of combustible material, a
noncombustible, nonventilating thimble shall be used at the
point of passage. The thimble shall extend at least 18 inches
(457 mm) above and 6 inches (152 mm) below the roof with
the annular space open at the bottom and closed only at the
top. The thimble shall be sized in accordance with Section
C503.10.15.
CS(Q>3.7o6 lestallation. Single- wall metal pipe shall not origi-
nate in any unoccupied attic or concealed space and shall not
pass through any attic, inside wall, concealed space, or floor.
The installation of a single- wall metal pipe through an exte-
rior combustible wall shall comply with Section C503. 10. 15.
Single-wall metal pipe used for venting an incinerator shall
be exposed and readily examinable for its full length and shall
have suitable clearances maintained.
C5(0i3.7o7 Clearances. Minimum clearances from sin-
gle-wall metal pipe to combustible material shall be in
accordance with Table C503.7.7. The clearance from sin-
gle-wall metal pipe to combustible material shall be permit-
ted to be reduced where the combustible material is
protected as specified for vent connectors in Table C308.2.
C5(D>3o7.8 Size of single- wall metal pipe. A venting system
constructed of single-wall metal pipe shall be sized in accor-
dance with one of the following methods and the appliance
manufacturer's instructions:
1 . For a draft-hood-equipped appliance, in accordance
with Section C504.
2. For a venting system for a single appliance with a
draft hood, the areas of the connector and the pipe
each shall be not less than the area of the appliance
flue collar or draft hood outlet, whichever is smaller.
The vent area shall not be greater than seven times the
draft hood outlet area.
3. Other approved engineering methods.
C503.7.9 Pipe geometry. Any shaped single-wall metal
pipe shall be permitted to be used, provided that its equiva-
lent effective area is equal to the effective area of the round
pipe for which it is substituted, and provided that the mini-
mum internal dimension of the pipe is not less than 2 inches
(51 mm).
C503.7.10 Termination capacity. The vent cap or a roof
assembly shall have a venting capacity not less than that of
the pipe to which it is attached.
C503.7.11 Support of single- wall metal pipe. All portions
of single- wall metal pipe shall be supported for the design
and weight of the material employed.
C503.7.12 Marking. Single- wall metal pipe shall comply
with the marking provisions of Section C503.6.12.
C503.8 Venting system termination location. The location of
venting system terminations shall comply with the following
(see Appendix C-C):
1. A mechanical draft venting system shall terminate at
least 3 feet (914 mm) above any forced- air inlet located
within 10 feet (3048 mm).
Exceptions:
1 . This provision shall not apply to the combus-
tion air intake of a direct- vent appliance.
2. This provision shall not apply to the separation
of the integral outdoor air inlet and flue gas dis-
charge of listed outdoor appliances.
TABLE C503.7.7^
CLEARANCES FOR CONNECTORS
APPLIANCE
MINIMUM DISTANCE FROM COMBUSTIBLE MATERIAL
Listed Type B gas
vent material
Listed Type L
vent material
Single-wall
metal pipe
Factory-built
chimney sections
Listed appliances with draft hoods and appliances listed for
use with Type B gas vents
As listed
As Usted
6 inches
As listed
Residential boilers and furnaces with listed gas conversion
burner and with draft hood
6 inches
6 inches
9 inches
As listed
Residential appliances listed for use with Type L vents
Not permitted
As listed
9 inches
As listed
Listed gas-fired toilets
Not permitted
As listed
As listed
As listed
Unlisted residential appliances with draft hood
Not permitted
6 inches
9 inches
As listed
Residential and low-heat appliances other than above
Not permitted
9 inches
18 inches
As listed
Medium-heat appliances
Not permitted
Not permitted
36 inches
As listed
For SI: 1 inch = 25.4 mm.
a. These clearances shall apply unless the manufacturer's installation instructions for a listed appliance or connector specify different clearances, in which case the
listed clearances shall apply.
117.72
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
2. A mechanical draft venting system, excluding
direct- vent appliances, shall terminate at least 4 feet
(1219 mm) below, 4 feet (1219 mm) horizontally from,
or 1 foot (305 mm) above any door, operable window, or
gravity air inlet into any building. The bottom of the vent
terminal shall be located at least 12 inches (305 mm)
above grade.
3. The vent terminal of a direct- vent appliance with an
input of 10,000 Btu per hour (3 kW) or less shall be
located at least 6 inches (152 mm) from any air opening
into a building, and such an appliance with an input over
10,000 Btu per hour (3 kW) but not over 50,000 Btu per
hour (14.7 kW) shall be installed with a 9-inch (230 mm)
vent termination clearance, and an appliance with an
input over 50,000 Btu/h (14.7 kw) shall have at least a
12-inch (305 mm) vent termination clearance. The bot-
tom of the vent terminal and the air intake shall be
located at least 12 inches (305 mm) above grade.
4. Through-the-wall vents for Category II and IV appli-
ances and noncategorized condensing appliances shall
not terminate over public walkways or over an area
where condensate or vapor could create a nuisance or
hazard or could be detrimental to the operation of regula-
tors, rehef valves, or other equipment. Where local expe-
rience indicates that condensate is a problem with
Category I and III appliances, this provision shall also
apply.
C503.9 Condensation drainage. Provisions shall be made to
collect and dispose of condensate from venting systems serv-
ing Category II and IV appliances and noncategorized con-
densing appliances in accordance with Section C503.8, Item 4.
Where local experience indicates that condensation is a prob-
lem, provision shall be made to drain off and dispose of con-
densate from venting systems serving Category I and III
appliances in accordance with Section C503.8, Item 4.
€503.10 Vent connectors for Category I equipment. Vent
connectors for Category I equipment shall comply with Sec-
tions C503.10.1 through C503.10.16.
C503.10.1 Where required. A vent connector shall be used
to connect an appliance to a gas vent, chimney or single- wall
metal pipe, except where the gas vent, chimney or sin-
gle-wall metal pipe is directly connected to the appliance.
€503. 10.2 Materials. Vent connectors shall be constructed
in accordance with Sections C503. 10.2.1 through
C503.10.2.5.
C503.10.2.1 General. A vent connector shall be made of
noncombustible corrosion-resistant material capable of
withstanding the vent gas temperature produced by the
appliance and of sufficient thickness to withstand
physical damage.
€503.10.2.2 Vent connectors located in uncondi-
tioned areas. Where the vent connector used for an
appliance having a draft hood or a Category I appliance is
located in or passes through attics, crawl spaces or other
unconditioned spaces, that portion of the vent connector
shall be listed Type B, Type L or listed vent material hav-
ing equivalent insulation properties.
Exception: Single- wall metal pipe located within the
exterior walls of the building in areas having a local
99-percent winter design temperature of 5°F (-15°C)
or higher shall be permitted to be used in uncondi-
tioned spaces other than attics, garages and crawl
spaces.
C503.10.2.3 Residential-type appliance connectors.
Where vent connectors for residential-type appliances
are not installed in attics or other unconditioned spaces,
connectors for listed appliances having draft hoods,
appliances having draft hoods and equipped with listed
conversion burners and Category I appliances shall be
one of the following:
1. Type B or L vent material;
2. Galvanized sheet steel not less than 0.018 inch
(0.46 mm) thick;
3. Aluminum (1100 or 3003 alloy or equivalent)
sheet not less than 0.027 inch (0.69 mm) thick;
4. Stainless steel sheet not less than 0.012 inch (0.31
mm) thick;
5. Smooth interior wall metal pipe having resistance
to heat and corrosion equal to or greater than that
of Item 2, 3 or 4 above; or
6. A hsted vent connector.
Vent connectors shall not be covered with insulation.
Exception: Listed insulated vent connectors shall be
installed according to the terms of their listing.
C503. 10.2.4 Low-heat equipment. A vent connector
for a nonresidential, low-heat appliance shall be a fac-
tory-built chimney section or steel pipe having resistance
to heat and corrosion equivalent to that for the appropri-
ate galvanized pipe as specified in Table C503. 10.2.4.
Factory-built chimney sections shall be joined together
in accordance with the chimney manufacturer's instruc-
tions.
TABLE C503.1 0.2.4
MINIMUM THICKNESS FOR GALVANIZED STEEL VENT
CONNECTORS FOR LOW-HEAT APPLIANCES
DIAMETER OF CONNECTOR
(inches)
MINIMUM THICKNESS
(inch)
Less than 6
0.019
6 to less than 10
0.023
10 to 12 inclusive
0.029
14 to 16 inclusive
0.034
Over 16
0.056
For SI: 1 inch = 25.4 mm.
C503.10.2.5 Medium-heat appliances. Vent connec-
tors for medium-heat appliances and commercial and
industrial incinerators shall be constructed of fac-
tory-built medium-heat chimney sections or steel of a
thickness not less than that specified in Table
C503. 10.2.5 and shall comply with the following:
1 . A steel vent connector for an appliance with a vent
gas temperature in excess of 1,000°F (538°C)
2007 OREGON MECHANICAL SPECIALTY CODE
117.73
APPENDIX C
measured at the entrance to the connector shall be
lined with medium-duty fire brick (ASTM C 64,
Type F), or the equivalent.
2. The lining shall be at least 272 inches (64 mm)
thick for a vent connector having a diameter or
greatest cross-sectional dimension of 18 inches
(457 mm) or less.
3. The lining shall be at least 4V2 inches (114 mm)
thick laid on the 4 Vj-inch (114 mm) bed for a vent
connector having a diameter or greatest
cross-sectional dimension greater than 18 inches
(457 mm).
4. Factory-built chimney sections, if employed,
shall be joined together in accordance with the
chimney manufacturer's instructions.
TABLE C503.1 0.2.5
llNIWiUiVi THICKNESS FOR STEEL VENT CONNECTORS FOR
EVIEDIUiVl-HEAT APPLIANCES AND COMMERCIAL AND
INDUSTRIAL INCINERATORS VENT CONNECTOR SIZE
DIAMETER
(inches)
AREA
(square inches)
iVilNIIVIUiU) THICKNESS
(inch)
Up to 14
Up to 154
0.053
Over 14 to 16
154 to 201
0.067
Over 16 tol8
201 to 254
0.093
Over 18
Larger than 254
0.123
For SI: 1 inch = 25.4 mm, 1 square inch - 645.16 mm^.
C5O3.10.3 Size of vent comeector. Vent connectors shall
be sized in accordance with Sections C503. 10.3.1 through
C503. 10.3.5.
C5<0)3,1®.3.1 Single draft hood and fan-assisted. A
vent connector for an appliance with a single draft hood
or for a Category I fan-assisted combustion system
appliance shall be sized and installed in accordance
with Section C504 or other approved engineering meth-
ods.
C503,103.2 Meltiple draft hood. For a single appli-
ance having more than one draft hood outlet or flue col-
lar, the manifold shall be constructed according to the
instructions of the appliance manufacturer. Where there
are no instructions, the manifold shall be designed and
constructed in accordance with approved engineering
practices. As an alternate method, the effective area of
the manifold shall equal the combined area of the flue
collars or draft hood outlets and the vent connectors
shall have a minimum 1-foot (305 mm) rise.
CS§3. 10.33 Multiple appliances. Where two or more
appliances are connected to a common vent or chimney,
each vent connector shall be sized in accordance with
Section C504 or other approved engineering methods.
As an alternative method applicable only when all of
the appliances are draft hood equipped, each vent con-
nector shall have an effective area not less than the area
of the draft hood outlet of the appliance to which it is
connected.
CS©3.10,3.4 Common connector/manifold. Where
two or more appliances are vented through a common
vent connector or vent manifold, the common vent con-
nector or vent manifold shall be located at the highest
level consistent with available headroom and the
required clearance to combustible materials and shall
be sized in accordance with Section C504 or other
approved engineering methods.
As an alternate method applicable only where there
are two draft hood-equipped appliances, the effective
area of the common vent connector or vent manifold
and all junction fittings shall be not less than the area of
the larger vent connector plus 50 percent of the area of
the smaller flue collar outlet.
€503.10.3,5 Size increase. Where the size of a vent
connector is increased to overcome installation limita-
tions and obtain connector capacity equal to the appli-
ance input, the size increase shall be made at the
appliance draft hood outlet.
C503.10.4 Two or more appliances connected to a sin-
gle vent. Where two or more vent connectors enter a com-
mon gas vent, chimney flue, or single-wall metal pipe, the
smaller connector shall enter at the highest level consistent
with the available headroom or clearance to combustible
material. Vent connectors serving Category I appliances
shall not be connected to any portion of a mechanical draft
system operating under positive static pressure, such as
those serving Category III or IV appliances.
C503.10.5 Clearance. Minimum clearances from vent
connectors to combustible material shall be in accordance
with Table C503.7.7.
Exception: The clearance between a vent connector
and combustible material shall be permitted to be
reduced where the combustible material is protected as
specified for vent connectors in Table C308.2.
C503.10.6 Flow resistance. A vent connector shall be
installed so as to avoid turns or other construction features
that create excessive resistance to flow of vent gases.
C503.10.7 Joints. Joints between sections of connector
piping and connections to flue collars and draft hood out-
lets shall be fastened by one of the following methods:
1. Sheet metal screws.
2. Vent connectors of listed vent material assembled
and connected to flue collars or draft hood outlets in
accordance with the manufacturers' instructions.
3. Other approved means.
C503.10.8 Slope. A vent connector shall be installed with-
out dips or sags and shall slope upward toward the vent or
chimney at least V4 inch per foot (21 mm/m).
Exception; Vent connectors attached to a mechanical
draft system installed in accordance with the manufac-
turers' instructions.
C503.10.9 Length of vent connector. A vent connector
shall be as short as practical and the appliance located as
close as practical to the chimney or vent. The maximum
117.74
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
horizontal length of a single-wall connector shall be 75
percent of the height of the chimney or vent except for
engineered systems. The maximum horizontal length of a
Type B double- wall connector shall be 100 percent of the
height of the chimney or vent except for engineered sys-
tems. For a chimney or vent system serving multiple appli-
ances, the maximum length of an individual connector,
from the appliance outlet to the junction with the common
vent or another connector, shall be 100 percent of the
height of the chimney or vent.
0.10 Support. A vent connector shall be supported
for the design and weight of the material employed to
maintain clearances and prevent physical damage and sep-
aration of joints.
CS03.10.11 Chimney connection. Where entering a flue
in a masonry or metal chimney, the vent connector shall be
installed above the extreme bottom to avoid stoppage.
Where a thimble or slip joint is used to facilitate removal of
the connector, the connector shall be firmly attached to or
inserted into the thimble or slip joint to prevent the connec-
tor from falling out. Means shall be employed to prevent
the connector from entering so far as to restrict the space
between its end and the opposite wall of the chimney flue
(see Section C501. 9).
C503.10.12 Inspection. The entire length of a vent con-
nector shall be provided with ready access for inspection,
cleaning, and replacement.
C503.10,13 Fireplaces. A vent connector shall not be con-
nected to a chimney flue serving a fireplace unless the fire-
place flue opening is permanently sealed.
C503.10.14 Passage through ceilings, floors or walls.
Single- wall metal pipe connectors shall not pass through
any wall, floor or ceiling except as permitted by Sections
C503.7.4 and C503. 10.15.
C503.10.15 Single- wall connector penetrations of com-
bustible walls. A vent connector made of a single-wall
metal pipe shall not pass through a combustible exterior
wall unless guarded at the point of passage by a ventilated
metal thimble not smaller than the following:
1 . For listed appliances equipped with draft hoods and
appliances listed for use with Type B gas vents, the
thimble shall be not less than 4 inches (102 mm)
larger in diameter than the vent connector. Where
there is a run of not less than 6 feet ( 1 829 mm) of vent
connector in the open between the draft hood outlet
and the thimble, the thimble shall be permitted to be
not less than 2 inches (51 mm) larger in diameter
than the vent connector.
2. For unlisted appliances having draft hoods, the thim-
ble shall be not less than 6 inches (152 mm) larger in
diameter than the vent connector.
3. For residential and low-heat appliances, the thimble
shall be not less than 12 inches (305 mm) larger in
diameter than the vent connector.
Exception: In lieu of thimble protection, all combusti-
ble material in the wall shall be removed from the vent
connector a sufficient distance to provide the specified
clearance from such vent connector to combustible
material. Any material used to close up such opening
shall be noncombustible.
C503.10.16 Medium-heat connectors. Vent connectors
for medium-heat appliances shall not pass through walls or
partitions constructed of combustible material.
C503.ll Vent connectors for Category II, III and IV appli-
ances. Vent connectors for Category II, III and IV appliances
shall be as specified for the venting systems in accordance
with Section C503.4.
C503.12 Draft hoods and draft controls. The installation of
draft hoods and draft controls shall comply with Sections
C503. 12.1 through C503. 12.7.
C503.12.1 Appliances requiring draft hoods. Vented
appliances shall be installed with draft hoods.
Exception: Dual oven-type combination ranges;
incinerators; direct- vent appliances; fan-assisted com-
bustion system appliances; appliances requiring chim-
ney draft for operation; single firebox boilers equipped
with conversion burners with inputs greater than
400,000 Btu per hour (117 kw); appliances equipped
with blast, power or pressure burners that are not listed
for use with draft hoods; and appliances designed for
forced venting.
C503.12.2 Installation. A draft hood supplied with or
forming a part of a listed vented appliance shall be
installed without alteration, exactly as furnished and speci-
fied by the appliance manufacturer.
C503.12.2.1 Draft hood required. If a draft hood is not
supplied by the appliance manufacturer where one is
required, a draft hood shall be installed, shall be of a
listed or approved type and, in the absence of other
instructions, shall be of the same size as the appliance
flue collar. Where a draft hood is required with a con-
version burner, it shall be of a listed or approved type.
C503.12.2.2 Special design draft hood. Where it is
determined that a draft hood of special design is needed
or preferable for a particular installation, the installa-
tion shall be in accordance with the recommendations
of the appliance manufacturer and shall be approved.
C503.12.3 Draft control devices. Where a draft control
device is part of the appliance or is supplied by the appli-
ance manufacturer, it shall be installed in accordance with
the manufacturer's instructions. In the absence of manu-
facturer's instructions, the device shall be attached to the
flue collar of the appliance or as near to the appliance as
practical.
C503.12.4 Additional devices. Appliances (except incin-
erators) requiring a controlled chimney draft shall be per-
mitted to be equipped with a listed double-acting
barometric -draft regulator installed and adjusted in accor-
dance with the manufacturer's instructions.
C503.12.5 Location. Draft hoods and barometric draft
regulators shall be installed in the same room or enclosure
as the appliance in such a manner as to prevent any differ-
2007 OREGON MECHANICAL SPECIALTY CODE
117.75
APPENDIX C
ence in pressure between the hood or regulator and the
combustion air supply.
CS03.12.6 PositioHing. Draft hoods and draft regulators
shall be installed in the position for which they were
designed with reference to the horizontal and vertical
planes and shall be located so that the relief opening is not
obstructed by any part of the appliance or adjacent con-
struction. The appliance and its draft hood shall be located
so that the relief opening is accessible for checking vent
operation.
C503.12.7 Clearance. A draft hood shall be located so its
relief opening is not less than 6 inches (152 mm) from any
surface except that of the appliance it serves and the vent-
ing system to which the draft hood is connected. Where a
greater or lesser clearance is indicated on the appliance
label, the clearance shall be not less than that specified on
the label. Such clearances shall not be reduced.
C503.13 Maemally operated dampers. A manually oper-
ated damper shall not be placed in the vent connector for any
appliance. Fixed baffles shall not be classified as manually
operated dampers.
C5(D3.14 Aetomatically operated vent dampers. An auto-
matically operated vent damper shall be of a listed type.
C5(Q>3.15 Otostrectioms. Devices that retard the flow of vent
gases shall not be installed in a vent connector, chimney or
vent. The following shall not be considered as obstructions:
1 . Draft regulators and safety controls specifically listed
for installation in venting systems and installed in
accordance with the manufacturer's installation
instructions.
2. Approved draft regulators and safety controls that are
designed and installed in accordance with approved
engineering methods.
3. Listed heat reclaimers and automatically operated vent
dampers installed in accordance with the
manufacturer's installation instructions.
4. Approved economizers, heat reclaimers and recupera-
tors installed in venting systems of appliances not
required to be equipped with draft hoods, provided that
the appliance manufacturer's instructions cover the
installation of such a device in the venting system and
performance in accordance with Sections C503.3 and
C503.3.1 is obtained.
5. Vent dampers serving listed appliances installed in
accordance with Sections C504.2.1 and C504.3.1 or
other approved engineering methods.
SECTBOI
SIZING OF CATEGORY 1 APPLIANCE
VENTING SYSTEMS
C5®4.1 DelGmitioinis. The following definitions apply to the
tables in this section.
APPLIANCE CATEGORIZED VENT BIAME-
TEM/AREA. The minimum vent area/diameter permissible
for Category I appliances to maintain a nonpositive vent static
pressure when tested in accordance with nationally recog-
nized standards.
FAN-ASSISTED COMBUSTION SYSTEM. An appliance
equipped with an integral mechanical means to either draw or
force products of combustion through the combustion cham-
ber or heat exchanger.
FAN Min. The minimum input rating of a Category I
fan-assisted appliance attached to a vent or connector.
FAN Max. The maximum input rating of a Category I
fan-assisted appliance attached to a vent or connector.
Max. The maximum input rating of a Category I
draft-hood-equipped appliance attached to a vent or connec-
tor.
FAN + FAN. The maximum combined appliance input rating
of two or more Category I fan-assisted appliances attached to
the common vent.
FAN + NAT. The maximum combined appliance input rating
of one or more Category I fan-assisted appliances and one or
more Category I draft-hood-equipped appliances attached to
the common vent.
NA. Vent configuration is not allowed due to potential for
condensate formation or pressurization of the venting system,
or not applicable due to physical or geometric restraints.
NAT + NAT, The maximum combined appliance input rating
of two or more Category I draft-hood-equipped appliances
attached to the common vent.
C504.2 Application of single-appliance vent Tables
C504.2(l) through C504.2(6). The application of Tables
C504.2(l) through C504.2(6) shall be subject to the require-
ments of Sections C504.2.1 through C504.2.16.
CS04.2.1 Vent obstrnctions. These venting tables shall
not be used where obstructions, as described in Section
C503.15, are installed in the venting system. The installa-
tion of vents serving listed appliances with vent dampers
shall be in accordance with the appliance manufacturer's
instructions or in accordance with the following:
1. The maximum capacity of the vent system shall be
determined using the "NAT Max" column.
2. The minimum capacity shall be determined as if the
appliance were a fan-assisted appliance, using the
"FAN Min" column to determine the minimum
capacity of the vent system. Where the correspond-
ing "FAN Min" is "NA," the vent configuration shall
not be permitted and an alternative venting configu-
ration shall be utilized.
C504.2.2 Minimum size. Where the vent size determined
from the tables is smaller than the appliance draft hood
outlet or flue collar, the smaller size shall be permitted to
be used provided that all of the following requirements are
met:
1. The total vent height {H) is at least 10 feet (3048
mm).
117.76
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
2. Vents for appliance draft hood outlets or flue collars
12 inches (305 mm) in diameter or smaller are not
reduced more than one tablesize.
3. Vents for appliance draft hood outlets or flue collars
larger than 12 inches (305 mm) in diameter are not
reduced more than two table sizes.
4. The maximum capacity listed in the tables for a
fan-assisted appliance is reduced by 10 percent (0.90
X maximum table capacity).
5. The draft hood outlet is greater than 4 inches (102
mm) in diameter. Do not connect a 3-inch-diameter
(76 mm) vent to a 4-inch-diameter (102 mm) draft
hood outlet. This provision shall not apply to
fan-assisted appliances.
C504.2.3 Vent offsets. Single-appliance venting configu-
rations with zero (0) lateral lengths in Tables C504.2(l),
C504.2(2) and C504.2(5) shall not have elbows in the vent-
ing system. Single-appliance venting configurations with
lateral lengths include two 90-degree (1.57 rad) elbows.
For each additional elbow up to and including 45 degrees
(0.79 rad), the maximum capacity listed in the venting
tables shall be reduced by 5 percent. For each additional
elbow greater than 45 degrees (0.79 rad) up to and includ-
ing 90 degrees (1.57 rad), the maximum capacity listed in
the venting tables shall be reduced by 10 percent.
C504.2.4 Zero lateral. Zero (0) lateral (L) shall apply only
to a straight vertical vent attached to a top outlet draft hood
or flue collar.
C504.2.5 High-altitude installations. Sea-level input rat-
ings shall be used when determining maximum capacity
for high altitude installation. Actual input (derated for alti-
tude) shall be used for determining minimum capacity for
high altitude installation.
C504.2.6 Multiple input rate appliances. For appliances
with more than one input rate, the minimum vent capacity
(FAN Min) determined from the tables shall be less than
the lowest appliance input rating, and the maximum vent
capacity (FAN Max/NAT Max) determined from the tables
shall be greater than the highest appliance rating input.
C504.2.7 Liner system sizing and connections. Listed
corrugated metallic chimney liner systems in masonry
chimneys shall be sized by using Table C504.2(l) or
C504.2(2) for Type B vents with the maximum capacity
reduced by 20 percent (0.80 x maximum capacity) and the
minimum capacity as shown in Table C504.2(l) or
C504.2(2). Corrugated metallic liner systems installed
with bends or offsets shall have their maximum capacity
further reduced in accordance with Section C504.2.3. The
20-percent reduction for corrugated metallic chimney
liner systems includes an allowance for one long-radius
90-degree (1.57 rad) turn at the bottom of the liner.
Connections between chimney liners and listed dou-
ble-wall connectors shall be made with listed adapters
designed for such purpose.
C504.2.8 Vent area and diameter. Where the vertical vent
has a larger diameter than the vent connector, the vertical
vent diameter shall be used to determine the minimum vent
capacity, and the connector diameter shall be used to deter-
mine the maximum vent capacity. The flow area of the verti-
cal vent shall not exceed seven times the flow area of the
listed appliance categorized vent area, flue collar area, or
draft hood outlet area unless designed in accordance with
approved engineering methods.
C504.2.9 Chimney and vent locations. Tables C504.2(l),
C504.2(2), C504.2(3), C504.2(4) and C504.2(5) shall only
be used for chimneys and vents not exposed to the outdoors
below the roof line. A Type B vent or listed chimney lining
system passing through an unused masonry chimney flue
shall not be considered to be exposed to the outdoors. A
Type B vent shall not be considered to be exposed to the out-
doors where it passes through an unventilated enclosure or
chase insulated to a value of not less than R8.
Table C504.2(3) in combination with Table C504.2(6)
shall be used for clay-tile-lined exterior masonry chimneys,
provided that all of the following are met:
1. Vent connector is a Type B double wall.
2. Vent connector length is limited to 1 V2 feet for each
inch (18 mm per mm) of vent connector diameter.
3. The appliance is draft hood equipped.
4. The input rating is less than the maximum capacity
given by Table C504.2(3).
5. For a water heater, the outdoor design temperature is
not less than 5°F(-15°C).
6. For a space-heating appliance, the input rating is
greater than the minimum capacity given by Table
C504.2(6).
Where these conditions cannot be met, an alternative
venting design shall be used, such as a listed chimney lining
system.
Exception: The installation of vents serving listed appli-
ances shall be permitted to be in accordance with the
appliance manufacturer's installation instructions.
C504.2.10 Corrugated vent connector size. Corrugated
vent connectors shall be not smaller than the listed appli-
ance categorized vent diameter, flue collar diameter, or draft
hood outlet diameter.
C504.2.11 Vent connector size limitation. Vent connec-
tors shall not be increased in size more than two sizes greater
than the listed appliance categorized vent diameter, flue col-
lar diameter, or draft hood outlet diameter.
C504.2.12 Component commingling. In a single run of
vent or vent connector, different diameters and types of vent
and connector components shall be permitted to be used,
provided that all such sizes and types are permitted by the
tables.
C504.2.13 Draft hood conversion accessories. Draft hood
conversion accessories for use with masonry chimneys
venting listed Category I fan-assisted appliances shall be
listed and installed in accordance with the manufacturer's
installation instructions for such listed accessories.
2007 OREGON MECHANICAL SPECIALTY CODE
117.77
TABLE C504.2(1)
TYPE B DOUBLE-WALL GAS VENT
Number of Appliances
Single
Appliance Type
Category I
Appliance Vent Connection
Connected directly to vent
HEIGHT
(H)
(feet)
LATERAL
(L)
(feet)
VENT DIAiWETER— (D; inches
3
4
5
6
7
8
9
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
6
78
46
152
86
251
141
375
205
524
285
698
370
897
470
2
13
51
36
18
97
67
27
157
105
32
232
157
44
321
217
53
425
285
63
543
370
4
21
49
34
30
94
64
39
153
103
50
227
153
66
316
211
79
419
279
93
536
362
6
25
46
32
36
91
61
47
149
100
59
223
149
78
310
205
93
413
273
110
530
354
8
84
50
165
94
276
155
415
235
583
320
780
415
1,006
537
2
12
57
40
16
109
75
25
178
120
28
263
180
42
365
247
50
483
322
60
619
418
5
23
53
38
32
103
71
42
171
115
53
255
173
70
356
237
83
473
313
99
607
407
8
28
49
35
39
98
66
51
164
109
64
247
165
84
347
227
99
463
303
117
596
396
10
88
53
175
100
295
166
447
255
631
345
847
450
1,096
585
2
12
61
42
17
118
81
23
194
129
26
289
195
40
402
273
48
533
355
57
684
457
5
23
57
40
32
113
77
41
187
124
52
280
188
68
392
263
81
522
346
95
671
446
10
30
51
36
41
104
70
54
176
115
67
267
175
88
376
245
104
504
330
122
651
427
15
94
58
191
112
327
187
502
285
716
390
970
525
1,263
682
2
11
69
48
15
136
93
20
226
150
22
339
225
38
475
316
45
633
414
53
815
544
5
22
65
45
30
130
87
39
219
142
49
330
217
64
463
300
76
620
403
90
800
529
10
29
59
41
40
121
82
51
206
135
64
315
208
84
445
288
99
600
386
116
777
507
15
35
53
37
48
112
76
61
195
128
76
301
198
98
429
275
115
580
373
134
755
491
20
97
61
202
119
349
202
540
307
776
430
1,057
575
1,384
752
2
10
75
51
14
149
100
18
250
166
20
377
249
33
531
346
41
711
470
50
917
612
5
21
71
48
29
143
96
38
242
160
47
367
241
62
519
337
73
697
460
86
902
599
10
28
64
44
38
133
89
50
229
150
62
351
228
81
499
321
95
675
443
112
877
576
15
34
58
40
46
124
84
59
217
142
73
337
217
94
481
308
111
654
427
129
853
557
20
48
52
35
55
116
78
69
206
134
84
322
206
107
464
295
125
634
410
145
830
537
(continued)
TABLE C504.2(1)— continued
TYPE B DOUBLE-WALL GAS VENT
Number of Appliances
Single
Appliance Type
Category I
Appliance Vent Connection
Connected directly to vent
HEIGHT
(feet)
LATERAL
(L)
(feet)
VENT DIAMETER— (D^ inches
3
4
5
6
7
8
9
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
30
100
64
213
128
■ 374
220
587
336
853
475
1,173
650
1,548
855
2
9
81
56
13
166
112
14
283
185
18
432
280
27
613
394
33
826
535
42
1,072
700
5
21
77
54
28
160
108
36
275
176
45
421
273
58
600
385
69
811
524
82
1,055
688
10
27
70
50
37
150
102
48
262
171
59
405
261
77
580
371
91
788
507
107
1,028
668
15
33
64
NA
44
141
96
57
249
163
70
389
249
90
560
357
105
765
490
124
1,002
648
20
56
58
NA
53
132
90
66
237
154
80
374
237
102
542
343
119
743
473
139
977
628
30
NA
NA
NA
73
113
NA
88
214
NA
104
346
219
131
507
321
149
702
444
171
929
594
50
101
67
216
134
397
232
633
363
932
518
1,297
708
1,730
952
2
8
86
61
11
183
122
14
320
206
15
497
314
22
715
445
26
975
615
33
1,276
813
5
20
82
NA
27
177
119
35
312
200
43
487
308
55
702
438
65
960
605
77
1,259
798
10
26
76
NA
35
168
114
45
299
190
56
471
298
73
681
426
86
935
589
101
1,230
773
15
59
70
NA
42
158
■ NA
54
287
180
66
455
288
85
662
413
100
911
572
117
1,203
747
20
NA
NA
NA
50
149
na'
63
275
169
76
440
278
97
642
401
113
888
556
131
1,176
722
30
NA
NA
NA
69
131
NA
84
250
NA
99
410
259
123
605
376
141
844
522
161
1,125
670
100
NA
NA
NA
218
NA
407
NA
665
400
997
560
1,411
770
1,908
1,040
2
NA
NA
NA
10
194
NA
12
354
NA
13
566
375
18
831
510
21
1,155
700
25
1,536
935
5
NA
NA
NA
26
189
NA
33
347
NA
40
557
369
52
820
504
60
1,141
692
71
1,519
926
10
NA
. NA
NA
33
182
NA
43
335
NA
53
542
361
68
801
493
80
1,118
679
94
1,492
910
15
NA
NA
NA
40
174
NA
50
321
NA
62
528
353
80
782
482
93
1,095
666
109
1,465
895
20
NA
NA
NA
47
166
NA
59
311
NA
71
513
344
90
763
471
105
1,073
653
122
1,438
880
30
NA
NA
NA
NA ■
NA
NA
78
290
NA
92
483
NA
115
726
449
131
1,029
627
149
1,387
849
50
NA
NA
NA
NA
NA
NA
NA
NA
NA
147
428
NA
180
651
405
197
944
575
217
1,288
787
(continued)
TABLE C504.2(1)— continued
TYPE B DOUBLE-WALL GAS VENT
Number of Appliances
Single
Appliance Type
Category I
Appliance Vent Connection
Connected directly to vent
HEIGHT
(H)
(feet)
LATERAL
(feet)
VENT DIAMETER— (O) inches
10
12
14
16
18
20
22
24
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
6
1,121
570
1,645
850
2,267
1,170
2,983
1,530
3,802
1,960
4,721
2,430
5,737
2,950
6,853
3,520
2
75
675
455
103
982
650
138
1,346
890
178
1,769
1,170
225
2,250
1,480
296
2,782
1,850
360
3,377
2,220
426
4,030
2,670
4
110
668
445
147
975
640
191
1,338
880
242
1,761
1,160
300
2,242
1,475
390
2,774
1,835
469
3,370
2,215
555
4,023
2,660
6
128
661
435
171
967
630
219
1,330
870
276
1,753
1,150
341
2,235
1,470
437
2,767
1,820
523
3,363
2,210
618
4,017
2,650
8
1,261
660
1,858
970
2,571
1,320
3,399
1,740
4,333
2,220
5,387
2,750
6,555
3,360
7,838
4,010
2
71
770
515
98
1,124
745
130
1,543
1,020
168
2,030
1,340
212
2,584
1,700
278
3,196
2,110
336
3,882
2,560
401
4,634
3,050
5
115
758
503
154
1,110
733
199
1,528
1,010
251
2,013
1,330
311
2,563
1,685
398
3,180
2,090
476
3,863
2,545
562
4,612
3,040
8
137
746
490
180
1,097
720
231
1,514
1,000
289
2,000
1,320
354
2,552
1,670
450
3,163
2,070
537
3,850
2,530
630
4,602
3,030
10
1,377
720
2,036
1,060
2,825
1,450
3,742
1,925
4,782
2,450
5,955
3,050
7,254
3,710
8,682
4,450
2
68
852
560
93
1,244
850
124
1,713
1,130
161
2,256
1,480
202
2,868
1,890
264
3,556
2,340
319
4,322
2,840
378
5,153
3,390
5
112
839
547
149
1,229
829
192
1,696
1,105
243
2,238
1,461
300
2,849
1,871
382
3,536
2,318
458
4,301
2,818
540
5,132
3,371
10
142
817
525
187
1,204
795
238
1,669
1,080
298
2,209
1,430
364
2,818
1,840
459
3,504
2,280
546
4,268
2,780
641
5,099
3,340
15
20
1,596
840
2,380
1,240
3,323
1,720
4,423
2,270
5,678
2,900
7,099
3,620
8,665
4,410
10,393
5,300
2
63
1,019
675
86
1,495
985
114
2,062
1,350
147
2,719
1,770
186
3,467
2,260
239
4,304
2,800
290
5,232
3,410
346
6,251
4,080
5
105
1,003
660
140
1,476
967
182
2,041
1,327
229
2,696
1,748
283
3,442
2,235
355
4,278
2,777
426
5,204
3,385
501
6,222
4,057
10
135
977
635
177
1,446
936
227
2,009
1,289
283
2,659
1,712
346
3,402
2,193
432
4,234
2,739
510
5,159
3,343
599
6,175
4,019
15
155
953
610
202
1,418
905
257
1,976
1,250
318
2,623
1,675
385
3,363
2,150
479
4,192
2,700
564
5,115
3,300
665
6,129
3,980
1,756
930
2,637
1,350
3,701
1,900
4,948
2,520
6,376
3,250
7,988
4,060
9,785
4,980
11,753
6,000
2
59
1,150
755
81
1,694
1,100
107
2,343
1,520
139
3,097
2,000
175
3,955
2,570
220
4,916
3,200
269
5,983
3,910
321
7,154
4,700
5
101
1,133
738
135
1,674
1,079
174
2,320
1,498
219
3,071
1,978
270
3,926
2,544
337
4,885
3,174
403
5,950
3,880
475
7,119
4,662
10
130
1,105
710
172
1,641
1,045
220
2,282
1,460
273
3,029
1,940
334
3,880
2,500
413
4,835
3,130
489
5,896
3,830
573
7,063
4,600
15
150
1,078
688
195
1,609
1,018
248
2,245
1,425
306
2,988
1,910
372
3,835
2,465
459
4,786
3,090
541
5,844
3,795
631
7,007
4,575
20
167
1,052
665
217
1,578
990
273
2,210
1,390
335
2,948
1,880
404
3,791
2,430
495
4,737
3,050
585
5,792
3,760
689
6,953
4,550
(continued)
TABLE C504.2(1)— continued
TYPE B DOUBLE-WALL GAS VENT
Number of Appliances
Single
Appliance Type
Category I
Appliance Vent Connection
Connected directly to vent
m
o
>
z
o
>
l-
(A
M
m
o
HEIGHT
(H)
(feet)
LATERAL
m
(feet)
VENT DIAMETER— ('?) inches
10
12
14
16
18
20
22
24
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
30
1,977
1,060
3,004
1,550
4,252
2,170
5,725
2,920
7,420
3,770
9,341
4,750
11,483
5,850
13,848
7,060
2
54
1,351
865
74
2,004
1,310
98
2,786
1,800
127
3,696
2,380
159
4,734
3,050
199
5,900
3,810
241
7,194
4,650
285
8,617
5,600
5
96
1,332
851
127
1,981
1,289
164
2,759
1,775
206
3,666
2,350
252
4,701
3,020
312
5,863
3,783
373
7,155
4,622
439
8,574
5,552
10
125
1,301
829
164
1,944
1,254
209
2,716
1,733
259
3,617
2,300
316
4,647
2,970
386
5,803
3,739
456
7,090
4,574
535
8,505
5,471
15
143
1,272
807
187
1,908
1,220
237
2,674
1,692
292
3,570
2,250
354
4,594
2,920
431
5,744
3,695
507
7,026
4,527
590
8,437
5,391
20
160
1,243
784
207
1,873
1,185
260
2,633
1,650
319
3,523
2,200
384
4,542
2,870
467
5,686
3,650
548
6,964
4,480
639
8,370
5,310
30
195
1,189
745
246
1,807
1,130
305
2,555
1,585
369
3,433
2,130
440
4,442
2,785
540
5,574
3,565
635
6,842
4,375
739
8,239
5,225
50
2,231
1,195
3,441
1,825
4,934
2,550
6,711
3,440
8,774
4,460
11,129
5,635
13,767
6,940
16,694
8,430
2
41
1,620
1,010
66
2,431
1,513
86
3,409
2,125
113
4,554
2,840
141
5,864
3,670
171
7,339
4,630
209
8,980
5,695
251
10,788
6,860
5
90
1,600
996
118
2,406
1,495
151
3,380
2,102
191
4,520
2,813
234
5,826
3,639
283
7,295
4,597
336
8,933
5,654
394
10,737
6,818
10
118
1,567
972
154
2,366
1,466
196
3,332
2,064
243
4,464
2,767
295
5,763
3,585
355
7,224
4,542
419
8,855
5,585
491
10,652
6,749
15
136
1,536
948
177
2,327
1,437
222
3,285
2,026
274
4,409
2,721
330
5,701
3,534
396
7,155
4,511
465
8,779
5,546
542
10,570
6,710
20
151
1,505
924
195
2,288
1,408
244
3,239
1,987
300
4,356
2,675
361
5,641
3,481
433
7,086
4,479
506
8,704
5,506
586
10,488
6,670
30
183
1,446
876
232
2,214
1,349
287
3,150
1,910
347
4,253
2,631
412
5,523
3,431
494
6,953
4,421
577
8,557
5,444
672
10,328
6,603
100
2,491
1,310
3,925
2,050
5,729
2,950
7,914
4,050
10,485
5,300
13,454
6,700
16,817
8,600
20,578
10,300
2
30
1,975
1,170
44
3,027
1,820
72
4,313
2,550
95
5,834
3,500
120
7,591
4,600
138
9,577
5,800
169
11,803
7,200
204
14,264
8,800
5
82
1,955
1,159
107
3,002
1,803
136
4,282
2,531
172
5,797
3,475
208
7,548
4,566
245
9,528
5,769
293
11,748
7,162
341
14,204
8,756
10
108
1,923
1,142
142
2,961
1,775
180
4,231
2,500
223
5,737
3,434
268
7,478
4,509
318
9,447
5,717
374-
11,658
7,100
436
14,105
8,683
15
126
1,892
1,124
163
2,920
1,747
206
4,182
2,469
252
5,678
3,392
304
7,409
4,451
358
9,367
5,665
418
11,569
7,037
487
14,007
8,610
20
141
1,861
1,107
181
2,880
1,719
226
4,133
2,438
277
5,619
3,351
330
7,341
4,394.
387
9,289
5,613
452
11,482
6,975
523
13,910
8,537
30
170
1,802
1,071
215
2,803
1,663
265
4,037
2,375
319
5,505
3,267
378
7,209
4,279
446
9,136
5,509
514
11,310
6,850
592
13,720
8,391
50
241
1,688
1,000
292
2,657
1,550
350
3,856
2,250
415
5,289
3,100
486
6,956
4,050
572
8,841
5,300
659
10,979
6,600
752
13,354
8,100
For ST: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour - 0.2931 W.
>
TJ
T3
m
z
g
X
o
TABLE C504.2(2)
TYPE B DOUBLE-WALL GAS VENT
Number of Appliances
Single
Appliance Type
Category I
Appliance Vent Connection
Single-wall metal connector
HEIGHT
(H)
(feet)
LATERAL
{L)
(feet)
VENT DIAMETER— {D) inches
3 4 slelylsls io|i2
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
6
38
77
45
59
151
85
85
249
140
126
373
204
165
522
284
211
695
369
267
894
469
371
1,118
569
537
1,639
849
2
39
51
36
60
96
66
85
156
104
123
231
156
159
320
213
201
423
284
251
541
368
347
673
453
498
979
648
4
NA
NA
33
74
92
63
102
152
102
146
225
152
187
313
208
237
416
277
295
533
360
409
664
443
584
971
638
6
NA
NA
31
83
89
60
114
147
99
163
220
148
207
307
203
263
409
271
327
526
352
449
656
433
638
962
627
8
37
83
50
58
164
93
83
273
154
123
412
234
161
580
319
206
777
414
258
1,002
536
360
1,257
658
521
1,852
967
2
39
56
39
59
108
75
83
176
119
121
261
179
155
363
246
197
482
321
246
617
417
339
768
513
486
1,120
743
5
NA
NA
37
77
102
69
107
168
114
151
252
171
193
352
235
245
470
311
305
604
404
418
754
500
598
1,104
730
8
NA
NA
33
90
95
64
122
161
107
175
243
163
223
342
225
280
458
300
344
591
392
470
740
486
665
1,089
715
10
37
87
53
57
174
99
82
293
165
120
444
254
158
628
344
202
844
449
253
1,093
584
351
1,373
718
507
2,031
1,057
2
39
61
41
59
117
80
82
193
128
119
287
194
153
400
272
193
531
354
242
681
456
332
849
559
475
1,242
848
5
52
56
39
76
111
76
105
185
122
148
277
186
190
388
261
241
518
344
299
667
443
409
834
544
584
1,224
825
10
NA
NA
34
97
100
68
132
171
112
188
261
171
237
369
241
296
497
325
363
643
423
492
808
520
688
1,194
788
15
36
93
57
56
190
111
80
325
186
116
499
283
153
713
388
195
966
523
244
1,259
681
336
1,591
838
488
2,374
1,237
2
38
69
47
57
136
93
80
225
149
115
337
224
148
473
314
187
631
413
232
812
543
319
1,015
673
457
1,491
983
5
51
63
44
75
128
86
102
216
140
144
326
217
182
459
298
231
616
400
287
795
526
392
997
657
562
1,469
963
10
NA
NA
39
95
116
79
128
201
131
182
308
203
228
438
284
284
592
381
349
768
501
470
966
628
664
1,433
928
15
NA
NA
NA
NA
NA
72
158
186
124
220
290
192
272
418
269
334
568
367
404
742
484
540
937
601
750
1,399
894
20
35
96
60
54
200
118
78
346
201
114
537
306
149
772
428
190
1,053
573
238
1,379
750
326
1,751
927
473
2,631
1,346
2
37
74
50
56
148
99
78
248
165
113
375
248
144
528
344
182
708
468
227
914
611
309
1,146
754
443
1,689
1,098
5
50
68
47
73
140
94
100
239
158
141
363
239
178
514
334
224
692
457
279
896
596
381
1,126
734
547
1,665
1,074
10
NA
NA
41
93
129
86
125
223
146
177
344
224
222
491
316
277
666
437
339
866
570
457
1,092
702
646
1,626
1,037
15
NA
NA
NA
NA
NA
80
155
208
136
216
325
210
264
469
301
325
640
419
393
838
549
526
1,060
677
730
1,587
1,005
20
NA
NA
NA
NA
NA
NA
186
192
126
254
306
196
309
448
285
374
616
400
448
810
526
592
1,028
651
808
1,550
973
(continued)
o
u
m
O
O
TABLE C504.2(2)— continued
TYPE B DOUBLE-WALL GAS VENT
Number of Appliances
Single
Appliance Type
Category I
Appliance Vent Connection
Single-wall metal connector
m
O
z
>
z
o
>
l-
(O
13
m
o
>
HEIGHT
(H)
(feet)
LATERAL
{L)
(feet)
VENT DIAMETER— (D) inches
345678910 12
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
IVIax
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
30
34
99
63
53
211
127
76
372
219
110
584
334
144
849
472
184
1,168
647
229
1,542
852
312
1,971
1,056
454
2,996
1,545
2
37
80
56
55
164
111
76
281
183
109
429
279
139
610
392
175
823
533
219
1,069
698
296
1,346
863
424
1,999
1,308
5
49
74
52
72
157
106
98
271
173
136
417
271
171
595
382
215
806
521
269
1.049
684
366
1,324
846
524
1,971
1,283
10
NA
NA
NA
91
144
98
122
255
168
171
397
257
213
570
367
265
777
501
327
1,017
662
440
1,287
821
620
1,927
1,234
15
NA
NA
NA
115
131
NA
151
239
157
208
377
242
255
547
349
312
750
481
379
985
638
507
1,251
794
702
1,884
1.205
20
NA
NA
NA
NA
NA
NA
181
223
NA
246
357
228
298
524
333
360
723
461
433
955
615
570
1,216
768
780
1,841
1,166
30
NA
NA
NA
NA
NA
NA
NA
NA
NA
•NA
NA
NA
389
477
305
461
670
426
541
895
574
704
1,147
720
937
1,759
1,101
50
33
99
66
51
213
133
73
394
230
105
629
361
138
928
515
176
1,292
704
220
1,724
948
295
2,223
1,189
428
3,432
1,818
2
36
84
61
53
181
121
73
318
205
104
495
312
133
712
443
168
971
613
209
1,273
811
280
1,615
1.007
401
2,426
1,509
5
48
80
NA
70
174
117
94
308
198
131
482
305
164
696
435
204
953
602
257
1,252
795
347
1,591
991
496
2,396
1,490
10
NA
NA
NA
89
160
NA
118
292
186
162
461
292
203
671
420
253
923
583
313
1,217
765
418
1,551
963
589
2,347
1,455
15
NA
NA
NA
112
148
NA
145
275
174
199
441
280
244
646
405
299
894
562
363
1,183
736
481
1,512
934
668
2,299
1,421
20
NA
NA
NA
NA
NA
NA
176
257
NA
236
420
267
285
622
389
345
866
543
415
1,150
708
544
1,473
906
741
2,251
1,387
30
NA
NA
NA
NA
NA
NA
NA
NA
NA
315
376
NA
373
573
•NA
442
809
502
521
1,086
649
674
1,399
848
892
2,159
1,318
100
'NA
NA
NA
49
214
NA
69
403
NA
100
659
395
131
991
555
166
1,404
765
207
1,900
1,033
273
2,479
1,300
395
3,912
2,042
2
NA
NA
NA
51
192
NA
70
351
NA
98
563
373
125
828
508
158
1,152
698
196
1,532
933
259
1,970
1,168
371
3,021
1,817
5
NA
NA
NA
67
186
NA
90
342
NA
125
551
366
156
813
501
194
1,134
688
240
1,511
921
322
1,945
1,153
460
2,990
1,796
10
NA
NA
NA
85
175
NA
113
324
NA
153
532
354
191
789
486
238
1,104
672
293
1,477
902
389
1,905
1,133
547
2,938
1,763
15
NA
NA
NA
132
162
NA
138
310
NA
188
511
343
230
764
473
281
1,075
656
342
1,443
884
447
1,865
1,110
618
2,888
1,730
20
NA
NA
NA
NA
NA
NA
168
295
NA
224
487
NA
270
739
458
325
1,046
639
391
1,410
864
507
1,825
1,087
690
2,838
1,696
30
NA
NA
NA
NA
NA
NA
231
264
NA
301
448
NA
355
685
NA
418.
988
NA
491
1,343
824
631
1,747
1.041
834
2,739
1,627
50
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
540
584
NA
617
866
NA
711
1,205
NA
895
1,591
NA
1,138
2,547
1,489
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.293 1 W.
TABLE C504.2(3)
MASONRY CHIMNEY
Number of Appliances
Single
Appliance Type
Category I
Appliance Vent Connection
Type B double-wall connector
HEIGHT
(H)
(feet)
LATERAL
(feet)
TYPE B DOUBLE-WALL CONNECTOR DIAMETER— (D) inches
to be used with chimney areas within the size limits at bottom
3
4
5
6
7
8
9
10
12
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
6
2
NA
NA
28
NA
NA
52
NA
NA
86
NA
NA
130
NA
NA
180
NA
NA
247
NA
NA
320
NA
NA
401
NA
NA
581
5
NA
NA
25
NA
NA
49
NA
NA
82
NA
NA
117
NA
NA
165
NA
NA
231
NA
NA
298
NA
NA
376
NA
NA
561
8
2
NA
NA
29
NA
NA
55
NA
NA
93
NA
NA
145
NA
NA
198
NA
NA
266
84
590
350
100
728
446
139
1,024
651
5
NA
NA
26
NA
NA
52
NA
NA
,88
NA
NA
134
NA
NA
183
NA
NA
247
NA
NA
328
149
711
423
201
1,007
640
8
NA
NA
24
NA
NA
48
NA
NA
83
NA
NA
127
NA
NA
175
NA
NA
239
NA
NA
318
173
695
410
231
990
623
10
2
NA
NA
31
NA
NA
61
NA
NA
103
NA
NA
162
NA
NA
221
68
519
298
82
655
388
98
810
491
136
1,144
724
5
NA
NA
28
NA
NA
57
NA
NA
96
NA
NA
148
NA
NA
204
NA
NA
277
124
638
365
146
791
466
196
1,124
712
10
NA
NA
25
NA
NA
50
NA
NA
87
NA
NA
139
NA
NA
191
NA
NA
263
155
610
347
182
762
444
240
1,093
668
15
2
NA
NA
35
NA
NA
67
NA
NA
114
NA
NA
179
53
475
250
64
613
336
77
779
441
92
968
562
127
1,376
841
5
NA
NA
35
NA
NA
62
NA
NA
107
NA
NA
164
NA
NA
231
99
594
313
118
759
416
139
946
533
186
1,352
828
10
NA
NA
28
NA
NA
55
NA
NA
97
NA
NA
153
NA
NA
216
126
565
296
148
727
394
173
912
567
229
1,315
777
15
NA
NA
NA
NA
NA
48
NA
NA
89
NA
NA
141
NA
NA
201
NA
NA
281
17!
698
375
198
880
485
259
1,280
742
20
2
NA
NA
38
NA
NA
74
NA
NA
124
NA
NA
201
51
522
274
61
678
375
73
867
491
87
1,083
627
121
1,548
953
5
NA
NA
36
NA
NA
68
NA
NA
116
NA
NA
184
80
503
254
95
658
350
113
845
463
133
1,059
597
179
1,523
933
10
NA
NA
NA
NA
NA
60
NA
NA
107
NA
NA
172
NA
NA
237
122
627
332
143
811
440
167
1,022
566
221
1,482
879
15
NA
NA
NA
NA
NA
NA
NA
NA
97
NA
NA
159
NA
NA
220
NA
NA
314
165
780
418
191
987
541
251
1,443
840
20
NA
NA
NA
NA
NA
NA
NA
NA
83
NA
NA
148
NA
NA
206
NA
NA
296
186
750
397
214
955
513
277
1,406
807
(continued)
TABLE C504.2(3)— continued
MASONRY CHIMNEY
Number of Appliances
Single
Appliance Type
Category I
Appliance Vent Connection
Type B double-wall connector
HEIGHT
(H)
(feet)
LATERAL
(L)
(feet)
TYPE B DOUBLE-WALL CONNECTOR DIAMETER— (D) inches
to be used with chimney areas within the size limits at bottom
3
4
5
6
7
8
9
10
12
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
30
2
NA
NA
41
NA
NA
82
NA
NA
137
NA
NA
216
47
581
303
57
762
421
68
985
558
81
1,240
717
111
1,793
1,112
5
NA
NA
NA
NA
NA
76
NA
NA
128
NA
NA
198
75
561
281
90
741
393
106
962
526
125
1,216
683
169
1,766
1,094
10
NA
NA
NA
NA
NA
67
NA
NA
115
NA
NA
184
NA
NA
263
115
709
373
135
927
500
158
1,176
648
210
1,721
1,025
15
NA
NA
NA
NA
NA
NA
NA
NA
107
NA
NA
171
NA
NA
243
NA
NA
353
156
893
476
181
1,139
621
239
1,679
981
20
NA
NA
NA
NA
NA
NA
NA
NA
91
NA
NA
159
NA
NA
227
NA
NA
332
176
860
450
203
1,103
592
264
1,638
940
30
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
188
NA
NA
288
NA
NA
416
249
1,035
555
318
1,560
877
50
2
NA
NA
NA
NA
NA
92
NA
NA
161
NA
NA
251
NA
NA
351
51
840
477
61
1,106
633
72
1,413
812
99
2,080
1,243
5
NA
NA
NA
NA
NA
NA
NA
NA
151
NA
NA
230
NA
NA
323
83
819
445
98
1,083
596
116
1,387
774
155
2,052
1,225
10
NA
NA
NA
NA
NA
NA
NA
NA
138
NA
NA
215
NA
NA
304
NA
NA
424
126
1,047
567
147
1,347
733
195
2,006
1,147
15
NA
NA
NA
NA
NA
NA
NA
NA
127
NA
NA
199
NA
NA
282
NA
NA
400
146
1,010
539
170
1,307
702
222
1,961
1,099
20
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
185
NA
NA
264
NA
NA
376
165
977
511
190
1,269
669
246
1,916
1,050
30
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
327
NA
NA
468
233
1,196
623
295
1,832
984
Minimum Internal
Area of Chimney
(square inches)
12
19
28
38
50
63
78
95
132
Maximum Internal
Area of Chimney
(square inches)
49
88
137
198
.269
352
445
550
792
For SI: 1 inch = 25.4 mm, 1 square inch = 645. 16 mm^, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W.
TABLE C504.2(4)
MASONRY CHIMNEY
Number of Appliances
Single
Appliance Type
Category I
Appliance Vent Connection
Single-wall metal connector
ro
o
o
■>J
O
3D
m
o
o
m
o
>
z
o
>
r"
(/)
-0
m
o
HEIGHT
(H)
(feet)
LATERAL
m
(feet)
SINGLE-WALL METAL CONNECTOR DIAMETER— (D) inches
to be used with chimney areas within the size limits at bottom
3
4
5
6
7
8
9
10
12
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
6
2
NA
NA
28
NA
NA
52
NA
NA
86
NA
NA
130
NA
NA
180
NA
NA
247
NA
NA
319
NA
NA
400
NA
NA
580
5
NA
NA
25
NA
NA
48
NA
NA
81
NA
NA
116
NA
NA
164
NA
NA
230
NA
NA
297
NA
NA
375
NA
NA
560
8
2
NA
NA
29
NA
NA
55
NA
NA
93
NA
NA
145
NA
NA
197
NA
NA
265
NA
NA
349
382
725
445
549
1,021
650
5
NA
NA
26
NA
NA
51
NA
NA
87
NA
NA
133
NA
NA
182
NA
NA
246
NA
NA
327
NA
NA
422
673
1,003
638
8
NA
NA
23
NA
NA
47
NA
NA
82
NA
NA
126
NA
NA
174
NA
NA
237
NA
NA
317
NA
NA
408
747
985
621
10
2
NA
NA
31
NA
NA
61
NA
NA
102
NA
NA
161
NA
NA
220
216
518
297
271
654
387
373
808
490
536
1,142
722
5
NA
NA
28
NA
NA
56
NA
NA
95
NA
NA
147
NA
NA
203
NA
NA
276
334
635
364
459
789
465
657
1,121
710
10
NA
NA
24
NA
NA
49
NA
NA
86
NA
NA
137
NA
NA
189
NA
NA
261
NA
NA
345
547
758
441
771
1,088
665
15
2
NA
NA
35
NA
NA
67
NA
NA
113
NA
NA
178
166
473
249
211
611
335
264
776
440
362
965
560
520
1,373
840
5
NA
NA
32
NA
NA
61
NA
NA
106
NA
NA
163
NA
NA
230
261
591
312
325
775
414
444
942
531
637
1,348
825
10
NA
NA
27
NA
NA
54
NA
NA
96
NA
NA
151
NA
NA
214
NA
NA
294
392
722
392
531
907
504
749
1,309
774
15
NA
NA
NA
NA
NA
46
NA
NA
87
NA
NA
138
NA
NA
198
NA
NA
278
452
692
372
606
873
481
841
1,272
738
20
2
NA
NA
38
NA
NA
73
NA
NA
123
NA
NA
200
163
520
273
206
675
374
258
864
490
252
1,079
625
508
1,544
950
5
NA
NA
35
NA
NA
67
NA
NA
115
NA
NA
183
80
NA
252
255
655
348
317
842
461
433
1,055
594
623
1,518
930
10
NA
NA
NA
NA
NA
59
NA
NA
105
NA
NA
170
NA
NA
235
312
622
330
382
806
437
517
1,016
562
733
1,475
875
15
NA
NA
NA
NA
NA
NA
NA
NA
95
NA
NA
156
NA
NA
217
NA
NA
311
442
773
414
591
979
539
823
1,434
835
20
NA
NA
NA
NA
NA
NA
NA
NA
80
NA
NA
144
NA
NA
202
NA
NA
292
NA
NA
392
663
944
510
911
1,394
800
(continued)
to
o
o
O
J3
m
o
o
TABLE C504.2(4)— continued
MASONRY CHIMNEY
Number of Appliances
Single
Appliance Type
Category I
Appliance Vent Connection
Single-wall metal connector
HEIGHT
(H)
(feet)
LATERAL
(feet)
SINGLE-WALL METAL CONNECTOR DIAMETER— (D) inches
to be used with chimney areas within the size limits at bottom
3
4
5
6
7
8
9
10
12
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
30
2
NA
NA
41
NA
NA
81
NA
NA
136
NA
NA
215
158
578..
302
200
759
420
249
982
556
340
1,237
715
489
1,789
1,110
5
NA
NA
NA
NA
NA
75
NA
NA
127
NA
NA.
196
NA
NA
279
245
737
391
306
958
524
417
1,210
680
600
1,760
1,090
10
NA
NA
NA
NA
NA
66
NA
NA
113
NA
NA
182
NA
NA
260
300
703
370
370
920
496
500
1,168
644
708
1,713
1,020
15
NA
NA
NA
NA
NA
NA
NA
NA
105
NA
NA
168
NA
NA
240
NA
NA
349
428
884
471
572
1,128
615
798
1,668
975
20
NA
NA
NA
NA
NA
NA
NA
NA
88
NA
NA
155
NA
NA
223
NA
NA
327
NA
NA
445
643
1,089
585
883
1,624
932
30
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
182
NA
NA
281
NA
NA
408
NA
NA
544
1,055
1,539
865
50
2
NA
NA
NA
NA
NA
91
NA
NA
160
NA
NA
250
NA
NA
350
191
837
475
238
1,103
631
323
1,408
810
463
2,076
1,240
5
NA
NA
NA
NA
NA
NA
NA
NA
149
NA
NA
228
NA
NA
321
NA
NA
442
293
1,078
593
398
1,381
770
571
2,044
1,220
10
LNA_
NA
NA
NA
NA
NA'
NA
NA
136
NA
NA
212
NA
NA
301
NA
NA
420
355
1,038
562
447
1,337
728
674
1,994
1,140
15
NA
NA
NA
NA
NA
NA
NA
NA
124
NA
NA
195
NA.
NA
278
NA
NA
395
NA
NA
533
546
1,294
695
761
1,945
1,090
20
NA
NA
NA
NA
NA
NA
.NA
NA
NA
NA
NA
180
NA
NA
258
NA
NA
370
NA
NA
504
616
1,251
660
844
1,898
1,040
30
NA
NA
NA
NA
NA
48
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
318
NA
NA
458
NA
NA
610
1,009
1,805
970
Minimum
Internal Area of
Chimney
(square inches)
12
19
28
38
50
63
78
95
132
Maximum
Internal Area of
Chimney
(square inches)
49
88
137
198
269
352
445
550
792
For SI: 1 inch = 25.4 mm, 1 square inch - 645.16 mm^, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W.
APPENDIX C
TABLE C504.2(5)
SINGLE-WALL METAL PIPE OR TYPE B
ASBESTOS CEMENT VENT
Number of Appliances
Single
Appliance Type
Draft hood equipped
Appliance Vent Connection
Connected directly to pipe or vent
HEIGHT
(H)
(feet)
LATERAL
{L)
(feet)
VENT DIAMETER— (D) inches
3
4
5 I
6
7
8
10
12
MAXIIVIUM APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
6
39
70
116
170
232
312
500
750
2
31
55
94
141
194
260
415
620
5
28
51
88
128
177
242
390
600
8
42
76
126
185
252
340
542
815
2
32
61
102
154
210"
284
451
680
5
29
56
95
141
194
264
430
648
10
24
49
86
131
180
250
406
625
10
45
84
138
202
279
372
606
912
2
35
67
111
168
233
311
505
760
5
32
61
104
153
215
289
480
724
10
27
54
94
143
200
274
455
700
15
NA
46
84
130
186
258
432
666
15
49
91
151
223
312
420
684
1,040
2
39
72
122
186
260
350
570
865
5
35
67
110
170
240
325
540
825
10
30
58
103
158
223 •
308
514
795
15
NA
50
93
144
207
291
488
760
20
NA
NA
82
132
195
273
466
726
20
53
101
163
252
342
470
770
1,190
2
42
80
136
210
286
392
641
990
5
38
74
123
192
264
364
610
945
10
32
65
115
178
246
345
571
910
15
NA
55
104
163
228
326
550
870
20
NA
NA
91
149
214
306
525
832
30
56
108
183
276
384
529
878
1,370
2
44
84
148
230
320
441
730
1,140
5
NA
78
137
210
296
410
694
1,080
10
NA
68
125
196
274
388
656
1,050
15
NA
NA
113
177
258
366
625
1,000
20
NA
NA
99
163
240
344
596
960
30
NA
NA
NA
NA
192
295
540
890
50
NA
120
210
310
443
590
980
1,550
2
NA
95
171
260
370
492
820
1,290
5
NA
NA
159
234
342
474
780
1,230
10
NA
NA
146
221
318
456
730
1,190
15
NA
NA
NA
200
292
407
705
1,130
20
NA
NA
NA
185
276
384
670
1,080
30
NA
NA
NA
NA
222
330
605
1,010
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W
117.88
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C504.2(6)
EXTERIOR MASONRY CHIMNEY
Number of Appliances
Single
Appliance Type
NAT
Appliance Vent Connection
Type B double-wall connector
MINIMUM ALLOWABLE INPUT RATING OF SPACE-HEATING APPLIANCE
IN THOUSANDS OF BTU PER HOUR
VENT HEIGHT
(feet)
Internal area of chimney (square Inches)
12
19
28
38
50
63
78
113
37°F or Greater
Local 99% Winter Design Temperature: 37°F or Greater
6
8
10
15
NA
20
NA
NA
123
190
249
184
30
NA
NA
NA
NA
NA
393
334
50
NA
NA
NA
NA
NA
NA
NA
579
27 to 36°F
Local 99% Winter Design Temperature: 27 to 36°F
6
68
116
156
180
212
266
8
82
127
167
187
214
263
10
51
97
141
183
201
225
265
15
NA
NA
NA
NA
233
253
274
305
20
NA
NA
NA
NA
NA
307
330
362
30
NA
NA
NA
NA
NA
419
445
485
50
NA
NA
NA
NA
NA
NA
NA
763
17 to 26°F
Local 99% Winter Design Temperature: 1 7 to 26°F
6
NA
NA
NA
NA
NA
215
259
349
8
NA
NA
NA
NA
197
226
264
352
10
NA
NA
NA
NA
214
245
278
358
15
NA
NA
NA
NA
•NA
296
331
398
20
NA
NA
NA
NA
NA
352
387
457
30
NA
NA
NA
NA
NA
NA
507
581
50
NA
NA
NA
NA
NA
NA
NA
NA
5 to 16°F
Local 99% Winter Design Temperature: 5 to 16°F
6
NA
NA
NA
NA
NA
NA
NA
416
8
NA
NA
NA
NA
NA
NA
312
423
10
NA
NA
NA
NA
NA
289
331
430
15
NA
NA
NA
NA
NA
NA
393
485
20
NA
NA
NA
NA
NA
NA
450
547
30
NA
NA
NA
NA
NA
NA
NA
682
50
NA
NA
NA
NA
NA
NA
NA
972
-10to4°F
Local 99% Winter Design Temperature: -10 to 4°F
6
NA
NA
NA
NA
NA
NA
NA
484
8
NA
NA
NA
NA
NA
NA
NA
494
10
NA
NA
NA
NA
NA
NA
NA
513
15
NA
NA
NA
NA
NA
NA
NA
586
20
NA
NA
NA
NA
NA
NA
NA
650
30
NA
NA
NA
NA
NA
NA
NA
805
50
NA
NA
NA
NA
NA
NA
NA
1,003
-11°F or Lower
Local 99% Winter Design Temperature: -1 1°F or Lower
Not recommended for any vent configurations
Note: See Figure C-B-19 in Appendix C-B for a map showing local 99 percent winter design temperatures in the United States.
For SI: °C = [(°F - 32]/1.8, 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.293 1 W
2007 OREGON MECHANICAL SPECIALTY CODE
117.89
APPENDIX C
C5(D4.2.14 Table ieterpolation. Interpolation shall be
permitted in calculating capacities for vent dimensions
that fall between the table entries (see Example 3, Appen-
dix B).
€504.2,15 Extrapolatioini proMlbited., Extrapolation
beyond the table entries shall not be permitted.
€504.2.16 Eiigmeermg calculations. For vent heights less
than 6 feet (1829 mm) and greater than shown in the tables,
engineering methods shall be used to calculate vent capaci-
ties.
C504.3 Applicatioe of multiple appliance
C504.3(l) through C504,3(7), The application of Tables
C504.3(l) through C504.3(7) shall be subject to the require-
ments of Sections C504.3.1 through C504.3.27.
C504.3.1 Vent obstructions. These venting tables shall not
be used where obstructions, as described in Section
C503.15, are installed in the venting system. The installa-
tion of vents serving listed appliances with vent dampers
shall be in accordance with the appliance manufacturer's
instructions or in accordance with the following:
1 . The maximum capacity of the vent connector shall be
determined using the NAT Max column.
2. The maximum capacity of the vertical vent or chim-
ney shall be determined using the FAN-i-NAT column
when the second appliance is a fan-assisted appliance,
or the NAT+NAT column when the second appliance
is equipped with a draft hood.
3. The minimum capacity shall be determined as if the
appliance were a fan-assisted appliance.
3.1. The minimum capacity of the vent connector
shall be determined using the FAN Min col-
umn.
3.2. The FANh-FAN column shall be used where
the second appliance is a fan-assisted appli-
ance, and the FAN+NAT column shall be
used where the second appliance is equipped
with a draft hood, to determine whether the
vertical vent or chimney configuration is not
permitted (NA). Where the vent configuration
is NA, the vent configuration shall not be per-
mitted and an alternative venting configura-
tion shall be utilized.
€504.3.2 Connector length limit The vent connector shall
be routed to the vent utilizing the shortest possible route.
Except as provided in Section C504.3.3, the maximum vent
connector horizontal length shall be VI2 feet for each inch
(457 mm per mm) of connector diameter as shown in Table
C504.3.2.
C504.3,3 Connectors with longer lengths. Connectors
with longer horizontal lengths than those listed in Section
C504.3.2 are permitted under the following conditions:
1 . The maximum capacity (FAN Max or NAT Max) of
the vent connector shall be reduced 10 percent for
each additional multiple of the length allowed by
Section C504.3.2. For example, the maximum
length listed in Table C504.3.2 for a 4-inch (102
mm) connector is 6 feet (1829 mm). With a connec-
tor length greater than 6 feet (1829 mm) but not
exceeding 12 feet (3658 mm), the maximum capac-
ity must be reduced by 10 percent (0.90 x maximum
vent connector capacity). With a connector length
greater than 12 feet (3658 mm) but not exceeding 18
feet (5486 mm), the maximum capacity must be
reduced by 20 percent (0.80 x maximum vent capac-
ity).
For a connector serving a fan-assisted appliance, the
minimum capacity (FAN Min) of the connector shall
be determined by referring to the corresponding sin-
gle appliance table. For Type B double-wall connec-
tors, Table C504.2(l) shall be used. For single- wall
connectors. Table C504.2(2) shall be used. The
height {H) and lateral (L) shall be measured according
to the procedures for a single-appliance vent, as if the
other appliances were not present.
TABLE C504.3.2
iWAXIMUfVi VENT CONNECTOR LENGTH
CONNECTOR DIAMETER MAXIMUM
(inches)
CONNECTOR HORIZONTAL
LENGTH (feet)
3
4V2
4
6
5
1%
6
9
7
1072
8
12
9
I3V2
10
15
12
18
14
21
16
24
18
27
20
30
22
33
24
36
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
C504.3,4 Vent connector manifold. Where the vent con-
nectors are combined prior to entering the vertical portion of
the common vent to form a common vent manifold, the size
of the common vent manifold and the common vent shall be
determined by applying a 10-percent reduction (0.90 x
maximum common vent capacity) to the common vent
capacity part of the common vent tables. The length of the
common vent connector manifold (L,„) shjill not exceed 1 Vj
feet for each inch (457 mm per mm) of common vent con-
nector manifold diameter (Z)) (see Figure C-B-1 1).
C504.3.5 Common vertical vent offset. Where the com-
mon vertical vent is offset, the maximum capacity of the
common vent shall be reduced in accordance with Section
C504.3.6. The horizontal length of the common vent offset
117.90
2007 OREGON RflECHANICAL SPECIALTY CODE
APPENDIX C
(LJ shallnot exceed IV2 feet for each inch (457 mm per
mm) of common vent diameter.
C5043.6 Elbows in vents. For each elbow up to and includ-
ing 45 degrees (0.79 rad) in the common vent, the maximum
common vent capacity listed in the venting tables shall be
reduced by 5 percent. For each elbow greater than 45
degrees (0.79 rad) up to and including 90 degrees (1 .57 rad),
the maximum common vent capacity listed in the venting
tables shall be reduced by 10 percent.
C504.3.7 Elbows in connectors. The vent connector
capacities listed in the common vent sizing tables include
allowance for two 90-degree (1.57 rad) elbows. For each
additional elbow up to and including 45 degrees (0.79
rad), the maximum vent connector capacity listed in the
venting tables shall be reduced by 5 percent. For each
elbow greater than 45 degrees (0.79 rad) up to and includ-
ing 90 degrees (1.57 rad), the maximum vent connector
capacity listed in the venting tables shall be reduced by 10
percent.
C504.3.8 Common vent minimum size. The cross-sec-
tional area of the common vent shall be equal to or greater
than the cross-sectional area of the largest connector.
C504.3.9 Common vent fittings. At the point where tee or
wye fittings connect to a common vent, the opening size of
the fitting shall be equal to the size of the common vent.
Such fittings shall not be prohibited from having reduced-
size openings at the point of connection of appliance vent
connectors.
C504,3.9.1 Tee and wye fittings. Tee and wye fittings
connected to a common vent shall be considered as part
of the common vent and shallbe constructed of materials
consistent with that of the common vent.
C504.3.10 High-altitude installations. Sea-level input rat-
ings shall be used when determiiiing maximum capacity for
high-altitude installation. Actual input (derated for altitude)
shall be used for determining minimum capacity for
high-altitude installation.
C504.3.11 Connector rise measurement. Connector rise
(R) for each appliance connector shall be measured from the
draft hood outlet or flue collar to the centerline where the
vent gas streams come together.
C504.3.12 Vent height measurement. For multiple appli-
ances all located on one floor, available total height (H) shall
be measured from the highest draft hood outlet or flue collar
up to the level of the outlet of the common vent.
C504.3.13 Multistory height measurement. For multi-
story installations, available total height (//) for each seg-
ment of the system shall be the vertical distance between the
highest draft hood outlet or flue: collar entering that segment
and the centerline of the next higher interconnection tee (see
Figure C-B- 13).
C504.3.14 Multistory lowest portion sizing. The size of
the lowest connector and of the vertical vent leading to the
lowest interconnection of a multistory system shall be in
accordance with Table C504.2(i) or C504.2(2) for available
total height (H) up to the lowest interconnection (see Figure
C-B-14).
C504.3.15 Multistory common vents. Where used in mul-
tistory systems, vertical common vents shall be Type B dou-
ble wall and shall be installed with a listed vent cap.
G504.3.16 Multistory common vent offsets. Offsets in
multistory common vent systems shall be limited to a single
offset in each system, and systems with an offset shall com-
ply with all of the following:
1. The offset angle shall not exceed 45 degrees (0.79
rad) from vertical.
2. The horizontal length of the offset shall not exceed
1 V2 feet for each inch (457 mm per mm) of common
vent diameter of the segment in which the offset is
located.
3. For the segment of the common vertical vent con-
taining the offset, the common vent capacity listed in
the common venting tables shall be reduced by 20
percent (0.80 x maximum common vent capacity).
4. A multistory common vent shall not be reduced in
size above the offset.
C504.3.17 Vertical vent maximum size. Where two or
more appliances are connected to a vertical vent or chimney,
the flow area of the largest section of vertical vent or chim-
ney shall not exceed seven times the smallest listed appli-
ance categorized vent areas, flue collar area, or draft hood
outlet area unless designed in accordance with approved
engineering methods.
C504.3.18 Multiple input rate appliances. For appliances
with more than one input rate, the minimum vent connector
capacity (FAN Min) determined from the tables shall be less
than the lowest appliance input rating, and the maximum
vent connector capacity (FAN Max or NAT Max) deter-
mined from the tables shall be greater than the highest appli-
ance input rating.
C504.3.19 Liner system sizing and connections. Listed,
corrugated metallic chimney liner systems in masonry
chimneys shall be sized by using Table C504.3(l) or
C504.3(2) for Type B vents, with the maximum capacity
reduced by 20 percent (0.80 x maximum capacity) and the
minimum capacity as shown in Table C504.3(l) or
C504.3(2). Corrugated metallic liner systems installed with
bends or offsets shall have their maximum capacity further
reduced in accordance with Sections C504.3.5 and
C504.3.6. The 20-percent reduction for corrugated metallic
chimney liner systems includes an allowance for one
long-radius 90-degree (1.57 rad) turn at the bottom of the
liner. Where double-wall connectors are required, tee and
wye fittings used to connect to the common vent chimney
liner shall be listed double- wall fittings. Connections
between chimney liners and listed double- wall fittings shall
be made with listed adapter fittings designed for such pur-
pose.
C504.3.20 Chimney and vent location. Tables C504.3(l),
C504.3(2), C504.3(3), C504.3(4) and C504.3(5) shall only
be used for chimneys and vents not exposed to the outdoors
2007 OREGON MECHANICAL SPECIALTY CODE
117.91
APPENDIX C
below the roof line. A Type B vent or listed chimney lining
system passing through an unused masonry chimney flue
shall not be considered to be exposed to the outdoors. A
Type B vent shall not be considered to be exposed to the out-
doors where it passes through an unventilated enclosure or
chase insulated to a value of not less than R8.
Tables C504.3(6) and C504.3(7) shall be used for
clay-tile-lined exterior masonry chimneys, provided all of
the following conditions are met:
1. Vent connector is Type B double wall.
2. At least one appliance is draft hood equipped.
3. The combined appliance input rating is less than the
maximum capacity given by Table C504.3(6a) for
NAT+NAT or Table C504.3(7a) for FAN+NAT.
4. The input rating of each space-heating appliance is
greater than the minimum input rating given by Table
C504.3(6b) for NAT+NAT or Table C504.3(7b) for
FAN+NAT.
5 . The vent connector sizing is in accordance with Table
C504.3(3).
Where these conditions cannot be met, an alternative
venting design shall be used, such as a listed chimney lining
system.
Exception: Vents serving listed appliances installed in
accordance with the appliance manufacturer's installa-
tion instructions.
C5®4.3<,21 Coraiector maximum and minimum size.
Vent connectors shall not be increased in size more than two
sizes greater than the listed appliance categorized vent
diameter, flue collar diameter, or draft hood outlet diameter.
Vent connectors for draft hood-equipped appliances shall
not be smaller than the draft hood outlet diameter. Where a
vent connector size(s) determined from the tables for a
fan-assisted appliance(s) is smaller than the flue collar
diameter, the use of the smaller size(s) shall be permitted
provided that the installation complies with all of the fol-
lowing conditions:
1 . Vent connectors for fan-assisted appliance flue col-
lars 12 inches (305 mm) in diameter or smaller are not
reduced by more than one table size [e.g., 12 inches to
10 inches (305 mm to 254 mm) is a one-size reduc-
tion] and those larger than 12 inches (305 mm) in
diameter are not reduced more than two table sizes
[e.g., 24 inches to 20 inches (610 mm to 508 mm) is a
two-size reduction].
2. The fan-assisted appliance(s) is common vented with
a draft-hood-equipped appliances(s).
3. The vent connector has a smooth interior wall.
C5®4.3.22 Component commingling. All combinations of
pipe sizes, single- wall and double- wall metal pipe shall be
allowed within any connector run(s) or within the common
vent, provided that all of the appropriate tables permit all of
the desired sizes and types of pipe, as if they were used for
the entire length of the subject connector or vent. Where sin-
gle-wall and Type B double-wall metal pipes are used for
vent connectors within the same venting system, the com-
mon vent must be sized using Table C504.3(2) or
C504.3(4), as appropriate.
C504.3.23 Draft hood conversion accessories. Draft hood
conversion accessories for use with masonry chimneys
venting listed Category I fan-assisted appliances shall be
listed and installed in accordance with the manufacturer's
installation instructions for such listed accessories.
C504.3.24 Multiple sizes permitted. Where a table per-
mits more than one diameter of pipe to be used for a connec-
tor or vent, all the permitted sizes shall be permitted to be
used.
C504.3.25 Table interpolation. Interpolation shall be per-
mitted in calculating capacities for vent dimensions that fall
between table entries (see Appendix B, Example 3).
C504.3.26 Extrapolation prohibited. Extrapolation
beyond the table entries shall not be permitted.
C5043.27 Engineering calculations. For vent heights less
than 6 feet (1829 mm) and greater than shown in the tables,
engineering methods shall be used to calculate vent capaci-
ties.
SECTION C505
DIRECT-VENT, INTEGRAL VENT,
I\/1ECHANICAL VENT AND
VENTILATION/EXHAUST HOOD VENTING
C505.1 General. The installation of direct- vent and integral
vent appliances shall be in accordance with Section C503.
Mechanical venting systems shall be designed and installed
in accordance with Section C503. Exhaust hood venting
used in conjunction with commercial cooking operations
shall be designed and installed in accordance with Section
507.
SECTION C506
FACTORY-BUILT CHIMNEYS
C506.1 Building heating appliances. Factory-built chim-
neys for building heating appliances producing flue gases
having a temperature not greater than 1,000°F (538°C), mea-
sured at the entrance to the chimney, shall be listed and
labeled in accordance with UL 103 and shall be installed and
terminated in accordance with the manufacturer's installation
instructions.
C506,2 Support. Where factory-built chimneys are supported
by structural members, such as joists and rafters, such mem-
bers shall be designed to support the additional load.
C506.3 Medium-heat appliances. Factory-built chinmeys for
medium-heat appliances producing flue gases having a tem-
perature above 1,000°F (538°C), measured at the entrance to
the chimney, shall be listed and labeled in accordance with UL
959 and shall be installed and terminated in accordance with
the manufacturer's installation instructions.
<
<
117.92
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C504.3(1)
TYPE B DOUBLE-WALL VENT
Number of Appliances
Two or more
Appliance Type
Category I
Appliance Vent Connection
Type B double-wall connector
VENT CONNECTOR CAPACITY
VENT
HEIGHT
(H)
(feet)
CONNECTOR
RISE
(fl)
(feet)
TYPE B DOUBLE-WALL VENT AND CONNECTOR DIAMETER— (0) inches
3
4
5
6
7
8
9
10
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
MIn
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
MIn
Max
Max
Min
Max
Max
MIn
Max
Max
6
1
22
37
26
35
66
46
46
106
72
58
164
104
77
225
142
92
296
185
109
376
237
128
466
289
2
23
41
31
37
75
55
48
121
86
60
183
124
79
253
168
95
333
220
112
424
282
131
526
345
3
24
44
35
38
81
62
49
132
96
62
199
139
82
275
189
97
363
248
114
463
317
134
575
386
8
1
22
40
27
35
72
48
49
114
76
64
176
109
84
243
148
100
320
194
118
408
248
138
507
303
2
23
44
32
36
80
57
51
128
90
66
195
129
86
269
175
103
356
230
121
454
294
141
564
358
3
24
47
36
37
87
64
53
139
101
67
210
145
88
290
198
105
384
258
123
492
330
143
612
402
10
1
22
43
28
34
78
50
49
123
78
65
189
113
89
257
154
106
341
200
125
436
257
146
542
314
2
23
47
33
36
86
59
51
136
93
67
206
134
91
282
182
109
374
238
128
479
305
149
596
372
3
24
50
37
37
92
67
52
146
104
69
220
150
94
303
205
111
402
268
131
515
342
152
642
417
15
1
21
50
30
33
89
53
47
142
83
64
220
120
88
298
163
110
389
214
134
493
273
162
609
333
2
22
53
35
35
96
63
49
153
99
66
235
142
91
320
193
112
419
253
137
532
323
165
658
394
3
24
55
40
36
102
71
51
163
HI
68
248
160
93
339
218
115
445
286
140
565
365
167
700
444
20
1
21
54
31
33
99
56
46
157
87
62
246
125
86
334
171
107
436
224
131
552
285
158
681
347
2
22
57
37
34
105
66
48
167
104
64
259
149
89
354
202
110
463
265
134
587
339
161
725
414
3
23
60
42
35
110
74
50
176
116
66
271
168
91
371
228
113
486
300
137
618
383
164
764
466
30
1
20
62
33
31
113
59
45
181
93
60
288
134
83
391
182
103
512
238
125
649
305
151
802
372
2
21
64
39
33
118
70
47
190
110
62
299
158
85
408
215
105
535
282
129
679
360
155
840
439
3
22
66
44
34
123
79
48
198
124
64
309
178
88
423
242
108
555
317
132
706
405
158
874
494
50
1
19
71
36
30
133
64
43
216
101
57
349
145
78
477
197
97
627
257
120
797
330
144
984
403
2
21
73
43
32,
137
76
45
223
119
59
358
172
81
490
234
100
645
306
123
820
392
148
1,014
478
3
22
75
48
33
141
86
46
229
134
61
366
194
83
502
263
103
661
343
126
842
441
151
1,043
538
100
1
18
82
37
28
158
66
40
262
104
53
442
150
73
611
204
91
810
266
112
1,038
341
135
1,285
417
2
19
83
44
30
161
79
42
267
123
55
447
178
75
619
242
94
822
316
115
1,054
405
139
1,306
494
3
20
84
50
31
163
89
44
272
138
57
452
109
78
627
272
97
834
355
118
1,069
455
142
1,327
555
COMMON VENT CAPACITY
VENT
HEIGHT
(H)
(feet)
TYPE B DOUBLE-WALL COMMON VENT DIAMETER (D)— inches
4
5
6
7
8
=
10
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
6
92
81
65
140
116
103
204
161
147
309
248
200
404
314
260
547
434
335
672
520
410
8
101
90
73
155
129
114
224
178
163
339
275
223
444
348
290
602
480
378
740
577
465
10
110
97
79
169
141
124
243
194
178
367
299
242
477
377
315
649
522
405
800
627
495
15
125
112
91
195
164
144
283
228
206
427
352
280
556
444
365
753
612
465
924
733
565
20
136
123
102
215
183
160
314
255
229
475
394
310
621
499
405
842
688
523
1,035
826
640
30
152
138
118
244
210
185
361
297
266
547
459
360
720
585
470
979
808
605
1,209
975
740
50
167
153
134
279
244
214
421
353
310
641
547
423
854
706
550
1,164
977
705
1,451
1,188
860
100
175
163
NA
311
277
NA
489
421
NA
751
658
479
1,025
873
625
1,408
1,215
800
1,784
1,502
975
(continued)
2007 OREGON MECHANICAL SPECIALTY CODE
117.93
APPENDIX C
TABLE C504.3(1)— continued
TYPE B DOUBLE-WALL VENT
Number of Appliances
Two or more
Appliance Type
Category I
Appliance Vent Connection
Type B double-wall connector
VENT CONNECTOR CAPACITY
VENT
HEIGHT
(H)
(feet)
CONNECTOR
RISE
(«)
(feet)
TYPE B DOUBLE-WALL VENT AND DIAMETER— (0) inches
12
14
16
18
20
22
24
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
6
2
174
764
496
223
1,046
653
281
1,371
853
346
1,772
1,080
NA
NA
NA
NA
NA
NA
NA
NA
NA
4
180
897
616
230
1,231
827
287
1,617
1,081
352
2,069
1,370
NA
NA
NA
NA
NA
NA
NA
NA
NA
6
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
8
2
186
822
516
238
1,126
696
298
1,478
910
365
1,920
1,150
NA
NA
NA
NA
NA
NA
NA
NA
NA
4
192
952
644
244
1,307
884
305
1,719
1,150
372
2,211
1,460
471
2,737
1,800
560
3,319
2,180
662
3,957
2,590
6
198
1,050
772
252
1,445
1,072
313
1,902
1,390
380
2,434
1,770
478
3,018
2,180
568
3,665
2,640
669
4,373
3,130
10
2
196
870
536
249
1,195
730
311
1,570
955
379
2,049
1,205
NA
NA
NA
NA
NA
NA
NA
NA
NA
4
201
997
664
256
1,371
924
318
1,804
1,205
387
2,332
1,535
486
2,887
1,890
581
3,502
2,280
686
4,175
2,710
6
207
1,095
792
263
1,509
1,118
325
1,989
1,455
395
2,556
1,865
494
3,169
2,290
589
3,849
2,760
694
4,593
3,270
15
2
214
967
568
272
1,334
790
336
1,760
1,030
408
2,317
1,305
NA
NA
NA
NA
NA
NA
NA
NA
NA
4
221
1,085
712
279
1,499
1,006
344
1,978
1,320
416
2,579
1,665
523
3,197
2,060
624
3,881
2,490
734
4,631
2,960
6
228
1,181
856
286
1,632
1,222
351
2,157
1,610
424
2,796
2,025
533
3,470
2,510
634
4,216
3,030
743
5,035
3,600
20
2
223
1,051
596
291
1,443
840
357
1,911
1,095
430
2,533
1,385
NA
NA
NA
NA
NA
NA
NA
NA
NA
4
230
1,162
748
298
1,597
1,064
365
2,116
1,395
438
2,778
1,765
554
3,447
2,180
661
4,190
2,630
772
5,005
3,130
6
237
1,253
900
307
1,726
1,288
373
2,287
1,695
450
2,984
2,145
567
3,708
2,650
671
4,511
3,190
785
5,392
3,790
30
2
216
1,217
632
286
1,664
910
367
2,183
1,190
461
2,891
1,540
NA
NA
NA
NA
NA
NA
NA
NA
NA
4
223
1,316
792
294
1,802
1,160
376
2,366
1,510
474
3,110
1,920
619
3,840
2,365
728
4,861
2,860
847
5,606
3,410
6
231
1,400
952
303
1,920
1,410
384
2,524
1,830
485
3,299
2,340
632
4,080
2,875
741
4,976
3,480
860
5,961
4,150
50
2
206
1,479
689
273
2,023
1,007
350
2,659
1,315
435
3,548
1,665
NA
NA
NA
NA
NA
NA
NA
NA
NA
4
213
1,561
860
281
2,139
1,291
359
2,814
1,685
447
3,730
2,135
580
4,601
2,633
709
5,569
3,185
851
6,633
3,790
6
221
1,631
1,031
290
2,242
1,575
369
2,951
2,055
461
3,893
2,605
594
4,808
3,208
724
5,826
3,885
867
6,943
4,620
100
2
192
1,923
712
254
2,644
1,050
326
3,490
1,370
402
4,707
1,740
NA
NA
NA
NA
NA
NA
NA
NA
NA
4
200
1,984
888
263
2,731
1,346
336
3,606
1,760
414
4,842
2,220
523
5,982
2,750
639
7,254
3,330
769
8,650
3,950
6
208
2,035
1,064
272
2,811
1,642
346
3,714
2,150
426
4,968
2,700
539
6,143
3,350
654
7,453
4,070
786
8,892
4,810
COMMON VENT CAPACITY
VENT
HEIGHT
(H)
(feet)
TYPE B DOUBLE-WALL COMMON VENT DIAMETER— (D) inches
12
14
16
_ 1. _
20
22
»
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
6
900
696
588
1,284
990
815
1,735
1,336
1,065
2,253
1,732
1,345
2,838
2,180
1,660
3,488
2,677
1970
4,206
3,226
2,390
8
994
773
652
1,423
1,103
912
1,927
1,491
1,190
2,507
1,936
1,510
3,162
2,439
1,860
3,890
2,998
2,200
4,695
3.616
2,680
10
1,076
841
712
1,542
1,200
995
2,093
1,625
1,300
2,727
2,113
1645
3,444
2,665
2,030
4,241
3,278
2,400
5,123
3,957
2,920
15
1,247
986
825
1,794
1,410
1,158
2,440
1,910
1,510
3,184
2,484
1,910
4,026
3,133
2,360
4,971
3,862
2,790
6,016
4,670
3,400
20
1,405
1,116
916
2,006
1,588
1,290
2,722
2,147
1,690
3,561
2,798
2,140
4,548
3,552
2,640
5,573
4,352
3,120
6,749
5,261
3,800
30
1,658
1,327
1,025
2,373
1,892
1,525
3,220
2,558
1,990
4,197
3,326
2,520
5,303
4,193
3,110
6,539
5,157
3,680
7,940
6,247
4,480
50
2,024
1,640
1,280
2,911
2,347
1,863
3,964
3,183
2,430
5,184
4,149
3,075
6,567
5,240
3,800
8,116
6,458
4,500
9,837
7,813
5,475
100
2,569
2,131
1,670
3,732
3,076
2,450
5,125
4,202
3,200
6,749
5,509
4,050
8,597
6,986
5,000
10,681
8,648
5,920
13,004
10,499
7,200
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W
117.94
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C504.3(2)
TYPE B DOUBLE-WALL VENT
Number of Appliances
Two or more
Appliance Type
Category I
Appliance Vent Connection
Single-wall metal connector
VENT CONNECTOR CAPACITY
VENT
HEIGHT
(«)
(feet)
CONNECTOR
RISE
(fl)
(feet)
SINGLE-WALL METAL VENT CONNECTOR DIAMETER— (D) inches
3
4
5
6
7
8
9
10
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
6
1
NA
NA
26
NA
NA
46
NA
NA
71
NA
NA
102
207
223
140
262
293
183
325
373
234
447
463
286
2
NA
NA
31
NA
NA
55
NA
NA.
85
168
182
123
■215
251
167
271
331
219
334
422
281
458
524
344
3
NA
NA
34
NA
NA
62
121
131
95
175
198
138
222
273
188
279
361
247
344
462
316
468
574
385
8
1
NA
NA
27
NA
NA
48
NA
NA
75
NA
NA
106
226
240
145
285
316
191
352
403
244
481
502
299
2
NA
NA
32
NA
NA
57
125
126
89
.184
193
127
234
266
173
293
353
228
360
450
292
492
560
355
3
NA
NA
35
NA
NA
64
130
138
100
191
208
144
241
287
197
302
381
256
370
489
328
501
609
400
10
1
NA
NA
28
NA
NA
50
119
121
77
182
186
110
240
253
150
302
335
196
372
429
252
506
534
308
2
NA
NA
33
84.
85
59
124
134
91
189
203
132
248
278'
183
311
369
235
381
473
302
517
589
368
3
NA
NA
36
89
91
67
129
144
102
197
217
148
257
299
203
320
398
265
391
511
339
528
637
413
15
1
NA
NA
29
79
87
52
116
138
81
177
214
116
238
291
158
312
380
208
397
482
266
556
596
324
2
NA
NA
34
83
94
62
121
150
97
185
230
138
246
314
189
321
411
248
407
522
317
568
646
387
3
NA
NA
39
87
100
70
127
160
109
193
243
157
255
333
215
331
438
281
418
557
360
579
690
437
20
1
49
56
30
78
97
54
115
152
84
175
238
120
233
325
165
306
425
217
390
538
276
546
664
336
2
52
59
36
82
103
64
120
163
101
182
252
144
243
346
197
317
453
259
400
574
331
558
709
403
3
55
62
40
87
107
72
125
172
113
190
264
164
252
363
223
326
476
294
412
607
375
570
750
457
30
1
47
60
31
77
110
57
112
175
89 .
169
278
129
226
380
175
296
497
230
378
630
294
528
779
358
2
51
62
37
81
115
67
117
185
106
177
290
152
236
397
208
307
521
274
389
662
349
541
819
425
3
54
64
42
85
119
76
122
193
120
185
300
172
244
412
235
316
542
309
400
690
394
555
855
482
50
1
46
69
34
75
128
60
109
207
96
162
336
137
217
460
188
284
604
245
364
768
314
507
951
384
2
49
71
40
79
132
72
114
215
113
170
345
164
226
473
223
294
623
293
376
793
375
520
983
458
3
52
72
45
83
136
82
119
221
123
178
353
186
235
486
252
304
640
331
387
816
423
535
1,013
518
100
1
45
79
34
71
150
61
104
249
98
153
424
140
205
585
192
269
774
249
345
993
321
476
1,236
393
2
48
80
41
75
153
73
110
255
115
160
428
167
212
593
228
279
788
299
358
1,011
383
490
1,259
469
3
51
81
46
79
157
85
114
260
129
168
433
190
222
603
256
289
801
339
368
1,027
431
506
1,280
527
COMIMON VENT CAPACITY
VENT
HEIGHT
(H)
(feet)
TYPE B DOUBLE-WALL COMMON VENT DIAMETER— (D) inches
4
5
6
._._ 7 .__._
8
9
1.
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
6
NA
78
64
NA
113
99
200
158
144
304
244
196
398
310
257
541
429
332
665
515
407
8
NA
87
71
NA
126'
111
218
173
159
331
269
218
436
342
285
592
473
373
730
569
460
10
NA
94
76
163
137
120
237
189
174
357
292
236
467
369
309
638
512
398
787
617
487
15
121
108
88
189
159
140
275
221
200
416
343
274
544
434
357
738
599
456
905
718
553
20
131
118
98
208
177
156
305
247
223
463
383
302
606
487
395
824
673
512
1,013
808
626
30
145
132
113
236
202
180
350
286
257
533
446
349
703
570
459
958
790
593
1,183
952
723
50
159
145
128
268
233
208
406
337
296
622
529
410
833
686
535
1,139
954
689
1,418
1,157
838
100
166
153
NA
297
263
NA
469
398
NA
726
633
464
999
846
606
1,378
1,185
780
1,741
1,459
948
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W
2007 OREGON MECHANICAL SPECIALTY CODE
117.95
APPENDIX C
TABLE C504.3(3)
MASONRY CHIMNEY
Number of Appliances
Two or more
Appliance Type
Category I
Appliance Vent Connection
Type B double-wall connector
VENT CONNECTOR CAPACITY
VENT
HEIGHT
(H)
(feet)
CONNECTOR
RISE
(feet)
TYPE B DOUBLE-WALL VENT CONNECTOR DIAMETER— (0) inches
3
4
s
_ s .
7
8
9
10
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
6
1
24
33
21
39
62
40
52
106
67
65
194
101
87
274
141
104
370
201
124
479
253
145
599
319
2
26
43
28
41
79
52
53
133
85
67
230
124
89
324
173
107
436
232
127
562
300
148
694
378
3
27
49
34
42
92
61
55
155
97
69
262
143
91
369
203
109
491
270
129
633
349
151
795
439
8
1
24
39
22
39
72
41
55
117
69
71
213
105
94
304
148
113
414
210
134
539
267
156
682
335
2
26
47
29
40
87
53
57
140
86
73
246
127
97
350
179
116
473
240
137
615
311
160
776
394
3
27
52
34
42
97
62
59
159
98
75
269
145
99
383
206
119
517
276
139
672
358
163
848
452
10
1
24
42
22
38
80
42
55
130
71
74
232
108
101
324
153
120
444
216
142
582
277
165
739
348
2
26
50
29
40
93
54
57
153
87
76
261
129
103
366
184
123
498
247
145
652
321
168
825
407
3
27
55
35
41
105
63
58
170
100
78
284
148
106
397
209
126
540
281
147
705
366
171
893
463
15
1
24
48
23
38
93
44
54
154
74
72
277
114
100
384
164
125
511'
229
153
658
297
184
824
375
2
25
55
31
39
105
55
56
174
89
74
299
134
103
419
192
128
558
260
156
718
339
187
900
432
3
26
59
35
41
115
64
57
189
102
76
319
153
105
448
215
131
597
292
159
760
382
190
960
486
20
1
24
52
24
37
102
46
53
172
77
71
313
119
98
437
173
123
584
239
150
752
312
180
943
397
2
25
58
31
39
114
56
55
190
91
73
335
138
101
467
199
126
625
270
153
805
354
184
1,011
452
' 3
26
63
35
40
123
65
57
204
104
75
353
157
104
493
222
129
661
301
156
851
396
187
1,067
505
30
I
24
54
25
37
111
48
52
192
82
69
357
127
96
504
187
119
680
255
145
883
337
175
1,115
432
2
25
60
32
38
122
58
54
208
95
72
376
145
99
531
209
122
715
287
149
928
378
179
1,171
484
3
26
64
36
40
131
66
56
221
107
74
392
163
101
554
233
125
746
317
152
968
418
182
1,220
535
50
1
23
51
25
36
116
51
51
209
89
67
405
143
92
582
213
115
798
294
140
1,049
392
168
1,334
506
2
24
59
32
37
127
61
53
225
102
70
421
161
95
604
235
118
827
326
143
1,085
433
172
1,379
558
3
26
64
36
39
135
69
55
237
115
72
435
80
98
624
260
121
854
357
147
1,118
474
176
1,421
611
100
]
23
46
24
35
108
50
49
208
92
65
428
155
88
640
237
109
907
334
134
1,222
454
161
1,589
596
2
24
53
31
37
120
60
51
224
105
67
444
174
92
660
260
113
933
368
138
1,253
497
165
1,626
651
3
25
59
35
38
130
68
53
237
118
69
458
193
94
679
285
116
956
399
141
1,282
540
169
1,661
705
COMMON VENT CAPACITY
VENT
HEIGHT
(H)
(feet)
MINIMUM INTERNAL AREA OF MASONRY CHIMNEY FLUE (square inches)
12
19
28
38
50
63
78
113
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
6
NA
74
25
NA
119
46
NA
178
71
NA
257
103
NA
351
143
NA
458
188
NA
582
246
1,041
853
NA
8
NA
80
28
NA
130
53
NA
193
82
NA
279
119
NA
384
163
NA
501
218
724
636
278
1,144
937
408
10
NA
84
31
NA
138
56
NA
207
90
NA
299
131
NA
409
177
606
538
236
776
686
302
1,226
1,010
454
15
NA
NA
36
NA
152
67
NA
233
106
NA
334
152
523
467
212
682
611
283
874
781
365
1,374
1,156
546
20
NA
NA
41
NA
NA
75
NA
250
122
NA
368
172
565
508
243
742
668
325
955
858
419
1,513
1,286
648
30
NA
NA
NA
NA
NA
NA
NA
270
137
NA
404
198
615
564
278
816
747
381
1,062
969
496
1,702
1,473
749
50
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
620
328
879
831
461
1,165
1,089
606
1,905
1,692
922
100
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
348
NA
NA
499
NA
NA
669
2,053
1,921
1,058
For SI: 1 inch = 25.4 mm, 1 square inch = 645. 16 mm?, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.293 1 W
117.96
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C504.3(4)
MASONRY CHIMNEY
Number of Appliances
Two or more
Appliance Type
Category I
Appliance Vent Connection
Single-wall metal connector
VENT CONNECTOR CAPACITY
VENT
HEIGHT
(H)
(feet)
CONNECTOR
RISE
(R)
(feet)
SINGLE-WALL METAL VENT CONNECTOR DIAMETER (D)— inches
3
4
5
6
7
8
9
10
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU/H
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
FAN
NAT
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
Min
Max
Max
6
1
NA
NA
21
NA
NA
39
NA
NA
66
179
191
100
231
271
140
292
366
200
362
474
252
499
594
316
2
NA
NA
28
NA
NA
52
NA
NA
84
186
227
123
239
321
172
301
432
231
373
557
299
509
696
376
3
NA
NA
34
NA
NA
61
134
153
97
193
258
142
247
365
202
309
491
269
381
634
348
519
793
437
8
1
NA
NA
21
NA
NA
40
NA
NA
68
195
208
103
250
298
146
313
407
207
387
530
263
529
672
331
2
NA
NA
28
NA
NA
52
137
139
85
202
240
125
258
343
177
323
465
238
397
607
309
540
766
391
3
NA
NA
34
NA
NA'
62
143
156
98
210
264
145
266
376
205
332
509
274
407
663
356
551
838
450
10
1
NA
NA
22
NA
NA
41
130
151
70
202
225
106
267
316
151
333
434
213
410
571
273
558
727
343
2
NA
NA
29
NA
NA
53
136
150
86
210
255
128
276
358
181
343
489
244
420
640
317
569
813
403
3
NA
NA
34
97
102
62
143
166
99
217
277
147
284
389
207
352
530
279
430
694
363
580
880
459
15
1
NA
NA
23
NA
NA
43
129
151
73
199
271
112
268
376
161
349
502
225
445
646
291
623
808
366
2
NA
NA
30
92
103
54
135
170
88
207
295
132
277
411
189
359
548
256
456
706
334
634
884
424
3
NA
NA
34
96
112
63
141
185
101
215
315
151
286
439
213
368
586
289
466
755
378
646
945
479
20
1
NA
NA
23
87
99
45
128
167
76
197
303
117
265
425
169
345
569
235
439
734
306
614
921
347
2
NA
NA
30
91
111
55
134
185
90
205
325
136
274
455
195
355
610
266
450
787
348
627
986
443
3
NA
NA
35
96
119
64
140
199
103
213
343
154
282
481
219
365
644
298
461
831
391
639
1,042
496
30
1
NA
NA
24
86
108
47
126
187
80
193
347
124
259
492
183
338
665
250
430
864
330
600
1,089
421
2
NA
NA
31
91
119
57
132
203
93
201
366
142
269
518
205
348
699
282
442
908
372
613
1,145
473
3
NA
NA
35
95
127
65
138
216
105
209
381
160
277
540
229
358
729
312
452
946
412
626
1,193
524
50
1
NA
NA
24
85
113
.50
124
204
87
188
392
139
252
567
208
328
778
287
417
1,022
383
582
1,302
492
2
NA
NA
31
89
123
60
130
218
100
196
408
158
262
588
230
339
806
320
429
1,058
425
596
1,346
545
3
NA
NA
35
94
131
68
136
231
112
205
422
176
271
607
255
349
831
351
440
1,090
466
610
1,386
597
100
1
NA
NA
23
84
104
49
122
200
89
182
410
151
243
617
232
315
875
328
402
1,181
444
560
1,537
580
2
NA
NA
30
88
115
59
127
215
102
190
425
169
253
636
254
326
899
361
415
1,210
488
575
1,570
634
3
NA
NA
34
93
124
67
133
228
115
199
438
188
262
654
279
337
921
392
427
1,238
529
589
1,604
687
COMMON VENT CAPACITY
VENT
HEIGHT
(H)
(feet)
MINIMUM INTERNAL AREA OF MASONRY CHIMNEY FLUE (square inches)
12
19
28
=»
50
63
78
113
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
■t-FAN
FAN
+NAT
NAT
+NAT
FAN
+FAN
FAN
+NAT
NAT
+NAT
FAN
■i-FAN
FAN
+NAT
NAT
+NAT
FAN
4-FAN
FAN
+NAT
NAT
+NAT
6
NA
NA
25
NA
118
45
NA
176
71
NA
255
102
NA
348
142
NA
455
187
NA
579
245
NA
846
NA
8
NA
NA
28
NA
128
52
NA
190
81
NA
276
118
NA
380
162
NA
497
217
NA
633
277
1,136
928
405
10
NA
NA
31
NA
136
56
NA
205
89
NA
295
129
NA
405
175
NA
532
234
171
680
300
1,216
1,000
450
15
NA
NA
36
NA
NA
66
NA
230
105
NA
335
150
NA
400
210
677
602
280
866
772
360
1,359
1,139
540
20
NA
NA
NA
NA
NA
74
NA
247
120
NA
362
170
NA
503
240
765
661
321
947
849
415
1,495
1,264
640
30
NA
NA
NA
NA
NA
NA
NA
NA
135
NA
398
195
NA
558
275
808
739
377
1,052
957
490
1,682
1,447
740
50
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
612
325
NA
821
456
1,152
1,076
600
1,879
1,672
910
100
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
494
NA
NA
663
2,006
1,885
1,046
For SI:
[ inch
= 25.4
mm,
1 squa
re incl
1 = 64
5.16m
irf, 1
foot =
304.8
mm, ]
Britis
h then
Tial un
it per
iour =
0.293
1 W
2007 OREGON MECHANICAL SPECIALTY CODE
117.97
APPENDIX C
TABLE C504.3(5)
SINGLE-WALL METAL PIPE OR TYPE ASBESTOS CEMENT VENT
Number of Appliances
Two or more
Appliance Type
Draft hood-equipped
Appliance Vent Connection
Direct to pipe or vent
VENT CONNECTOR CAPACITY
TOTAL VENT
HEIGHT
(H)
(feet)
CONNECTOR
RISE
(fl)
(feet)
VENT CONNECTOR DIAMETER— (O) inches
3
4
5 J
6
7
8
IVIAXIiWUM APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
6-8
1
21
40
68
102
146
'205
2
28
53
86
124
178
235
3
34
61
98
147
204
275
15
1
23
44
77
117
179
240
2
30
56
92
134
194
265
3
35
64
102
155
216
298
30 and up
1
25
49
84
129
190
270
2
31
58
97
145
211
295
, 3
36
68
107
164
232
321
COiWIViON VENT CAPACITY
TOTAL VENT
HEIGHT
(H)
(feet)
COMMON VENT DIAMETER— (D^ inches
4
5
6
7
8
10
12
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
6
48
78
111
155
205
320
NA
8
55
89
128
175
234
365
505
10
59
95
136
190
250
395
560
15
71
115
168
228
305
480
690
20
80
129
186
. 260
340
550
790
30
NA
147
215
300
400
650
940
50
NA
NA
NA
360
490
810
1,190
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W
117.98
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
TABLE C504.3(6a)
EXTERIOR MASONRY CHIMNEY
Number of
Appliances
Two or more
Appliance
Type
NAT + NAT
Appliance Vent
Connection
TypeB
double-wall
connector
Combined Appliance Maximum
input Rating in Thousands of Btu per Hour
VENT
HEIGHT
(feet)
INTERNAL AREA OF CHIMNEY (square
inches)
12
19
28
38
50
63
78
113
6
25
46
71
103
143
188
246
NA
8
28
53
82
119
163
218
278
408
10
31
56
90
131
177
236
302
454
15
NA
67
106
152
212
283
365
546
20
NA
NA
NA
NA
NA
325
419
648
30
NA
NA
NA
NA
NA
NA
496
749
50
NA
NA
NA
NA
NA
NA
NA
922
100
NA
NA
NA
NA
NA
NA
NA
NA
TABLE C504.3(6b)
EXTERIOR MASONRY CHIMNEY
Number of
Appliances
Two or more
Appliance
Type
NAT + NAT
Appliance Vent
Connection
TypeB
double-wall
connector
Minimum Allowable Input Rating of
Space-Heating Appliance In Thousands of Btu per Hour
VENT
HEIGHT
(feet)
INTERNAL AREA OF CHIMNEY (square inches)
12
19
28
38
50
63
78
113
37°F or
Greater
Lo(
:al 99%
l/Vinter D
esign T«
smperat
jre: 37''F
"orGreE
Iter
6
NA
8
10
15
NA
20
NA
NA
NA
NA
NA
184
30
NA
NA
NA
NA
NA
393
334
50
NA
NA
NA
NA
NA
NA
NA
579
100
NA
NA
NA
NA
NA
NA
NA
NA
27 to
se-F
_ocal 99
% Winte
r Design
Tempe
rature: 2
7 to 36°F
:
6
68
NA
NA
180
212
NA
8
82
NA
NA
187
214
263
10
51
NA
NA
NA
201
225
265
15
NA
NA
NA
NA
NA.
253
274
305
20
NA
NA
NA
NA
NA
307
330
362
30
NA
NA
NA
NA
■ NA
NA
445
485
50
NA.
NA
NA
NA
:na
NA
NA
763
100
NA
NA
NA
NA
. NA
NA
NA
NA
TABLE C504.3(6b)
EXTERIOR MASONRY CHJMNEY— continued
Minimum Allowable Input Rating of
Space-Heating Appliance in Thousands of Btu per Hour
VENT
HEIGHT
(feet)
INTERNAL AREA OF CHIMNEY (square inches)
12
19
28
38
50
63
78
113
17 to
26''F
1
.ocal 99% Winter Design Temperature: 17 to 26°F
6
NA
NA
NA
NA
NA
NA
NA
NA
8
NA
NA
NA
NA
NA
NA
264
352
10
NA
NA
NA
NA
NA
NA
278
358
15
NA
NA
NA
NA
NA
NA
331
398
20
NA
NA
NA
NA
NA
NA
387
457
30
NA
NA
NA
NA
NA
NA
NA
581
50
NA
NA
NA
NA
NA
NA
NA
862
100
NA
NA
NA
NA
NA
NA
NA
NA
5 to
le^F
Local 99% Winter Desig
1 Temperature: 5 to 1 6''F
6
NA
NA
NA
NA
NA
NA
NA
NA
8
NA
NA
NA
NA
NA
NA
NA
NA
10
NA
NA
NA
NA
NA
NA
NA
430
15
NA.
NA
NA
NA
NA
NA
NA
485
20
NA
NA
NA
NA
NA
NA
NA
547
30
NA
NA
NA
NA
NA
NA
NA
682
50
NA
NA
NA
NA
NA
NA
NA
NA
100
NA
NA
. NA
NA
NA
NA
NA
NA
4°For
Lower
Local 99% Winter Design Temperature: 4°F or Lower
Not recommended for any vent configurat
ons
Note: See Figure C-B-19 in Appendix C-B for a map showing local 99 percent
winter design temperatures in the United States.
For SI: °C = [(°F - 32]/I.8, 1 inch = 25.4 mm, 1 square inch = 645.16 mnf ,
1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W
2007 OREGON MECHANICAL SPECIALTY CODE
117.99
APPENDIX C
TABLE C504.3(7a)
EXTERIOR MASONRY CHIWINEY
Number of
Appliances
Two or more
Appliance
Type
FAN + NAT
Appliance Vent
Connection
TypeB
double-wall
connector
Combined Appliance fVlaximum
Input Rating in Thousands of Btu per Hour
VENT
HEIGHT
(feet)
INTERNAL AREA OF CHIiVINEY (square
inches)
12
19
28
38
50
63
78
113
6
74
119
178
257
351
458
582
853
8
80
130
193
279
384
501
636
937
10
84
138
207
299
409
538
686
1,010
15
NA
152
233
334
467
611
781
1,156
20
NA
NA
250
368
508
668
858
1,286
30
NA
NA
NA
404
564
747
969
1,473
50
NA
NA
NA
NA
NA
831
1,089
1,692
100
NA
NA
NA
NA
NA
NA
NA
1,921
TABLE C504.3(7b)
EXTERIOR IViASOINlRY CHIIVIEMEY
Number of
Appliances
Two or more
Appliance
Type
FAN -1- NAT
Appliance Vent
Connection
TypeB
double-wall
connector
iVlJnimum Allowable Input Rating of
Space-Heating Appliance in Thousands of Btu per Hour
VENT
HEIGHT
(feet)
INTERNAL AREA OF CHIMNEY (square inches)
12
19
28
38
50
63
78
113
37°F or
Greater
Lo<
:al 99%
Winter D
esign Tc
;mperat
jre: 37°F
= or Grej
Iter
6
8
10
15
NA
20
NA
NA
123
190
249
184
30
NA
NA
NA
334
398
393
334
50
NA
NA
NA
NA
NA
714
707
579
100
NA
NA
NA
NA
NA
NA
NA
1,600
27 to
36^
Local 99
% WInte
r Design
Tempe
rature: 2
7 to 36°F
6
68
116
156
180
212
266
8
82
127
167
187
214
263
10
51
97
141
183
210
225
265
15
NA
111
142
183
233
253
274
305
20
NA
NA
187
230
284
307
330
362
30
NA
NA
NA
330
319
419
445
485
50
NA
NA
NA
NA
NA
672
705
763
100
NA
NA
NA
NA
NA
NA
NA
1,554
TABLE C504.3(7b)
EXTERIOR MASONRY CHIMNEY— continued
Minimum Allowable Input Rating of
Space-Heating Appliance in Thousands of Btu per Hour
VENT
HEIGHT
(feet)
INTERNAL AREA OF CHIMNEY (square inches)
12
19
28
38
50
63
78
113
17 to
26°F
Local 99% Winter Design Temperature: 17 to 26°F
6
55
99
141
182
215
259
349
8
52
74
111
154
197
226
264
352
10
NA
90
125
169
214
245
278
358
15
NA
NA
167
212
263
296
331
398
20
NA
NA
212
258
316
352
387
457
30
NA
NA
NA
362
429
470
507
581
50
NA
NA
NA
NA
NA
723
766
862
100
NA
NA
NA
NA
NA
NA
NA
1,669
5 to
le-F
Local 99% Winter Design Temperature: 5 to 16°F
6
NA
78
121
166
214
252
301
416
8
NA
94
135
182
230
269
312
423
10
NA
111
149
198
250
289
331
430
15
NA
NA
193
247
305
346
393
485
20
NA
NA
NA
293
360
408
450
547
30
NA
NA
NA
377
450
531
580
682
50
NA
NA
NA
NA
NA
797
853
972
100
NA
NA
NA
NA
NA
NA
NA
1,833
-10 to
4»F
Local 99% Winter Design Temperature: -10 to 4<'F
6
NA
NA
145
196
249
296
349
484
8
NA
NA
159
213
269
320
371
494
10
NA
NA
175
231
292
339
397
513
15
NA
NA
NA
283
351
404
457
586
20
NA
NA
NA
333
408
468
528
650
30
NA
NA
NA
NA
NA
603
667
805
50
NA
NA
NA
NA
NA
NA
955
1,003
100
NA
NA
NA
NA
NA
NA J
NA
NA
-11 Tor
Lower
Lo
cal 99% Winter Design Temperature: -11 °F or Lower
Not recommended for any vent configurations
Note: See Figure C-B- 19 in Appendix C-B for a map showing local 99 percent
winter design temperatures in the United States.
For SI: °C = [(°F - 32]/1.8, 1 inch = 25.4 mm, 1 square inch = 645.16 mnf ,
1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W
117.100
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
SECTION C601
GENERAL
C601.1 Scope. This chapter shall govern the approval, installa-
> tion, construction, alteration and repair of the appliances and
equipment specifically identified herein.
SECTION C606
INCINERATORS AND CREMATORIES
C606.1 General. Incinerators and crematories shall be
installed in accordance with the manufacturer's installation
instructions.
SECTION C602
DECORATIVE APPLIANCES
FOR INSTALLATION IN FIREPLACES
C602.1 General. Decorative appliances for installation in
approved solid fuel-burning fireplaces shall be tested in accor-
dance with ANSI Z21.60 and shall be installed in accordance
with the manufacturer's installation instructions. Manually
lighted natural gas decorative appliances shall be tested in
accordance with ANSI Z21.84.
C602.2 Flame safeguard device. Decorative appliances for
installation in approved solid fuel -burning fireplaces, with the
exception of those tested in accordance with ANSI Z21.84,
shall utilize a direct ignition device, an ignitor or a pilot flame
to ignite the fuel at the main burner, and shall be equipped with
a flame safeguard device. The flame safeguard device shall
automatically shut off the fuel supply to a main burner or group
of burners when the means of ignition of such burners becomes
inoperative.
C602.3 Prohibited installations. Decorative appliances for
installation in fireplaces shall not be installed where prohibited
by Section C303.3.
SECTION C603
LOG LIGHTERS
> C603.1 General. Log lighters shall be installed in accordance
with the manufacturer's installation instructions.
SECTION C604
VENTED GAS FIREPLACES
(DECORATIVE APPLIANCES)
C604.1 General. Vented gas fireplaces shall be tested in accor-
dance with ANSI Z21 .50, shall be installed in accordance with
the manufacturer's installation instructions and shall be
designed and equipped as specified in Section C602.2.
C604.2 Access. Panels, grilles and access doors that are
required to be removed for normal servicing operations shall
not be attached to the building.
SECTION C605
VENTED GAS FIREPLACE HEATERS
C605.1 General. Vented gas fireplace heaters shall be installed
in accordance with the manufacturer's installation instructions,
shall be tested in accordance with ANSI Z21.88 and shall be
designed and equipped as specified in Section C602.2.
SECTION C607
COMMERCIAL-INDUSTRIAL INCINERATORS
C607.1 Incinerators, commercial-industrial. Commer-
cial-industrial-type incinerators shall be constructed and
installed in accordance with NFPA 82. '
SECTION C608
VENTED WALL FURNACES
C608.1 General. Vented wall furnaces shall be tested in
accordance with ANSI Z21 .86/CSA 2.32 and shall be installed
in accordance with the manufacturer's installation instructions.
C608.2 Venting. Vented wall furnaces shall be vented in accor-
dance with Section 503.
C608.3 Location. Vented wall furnaces shall be located so as
not to cause a fire hazard to walls, floors, combustible furnish-
ings or doors. Vented wall furnaces installed between bath-
rooms and adjoining rooms shall not circulate air from
bathrooms to other parts of the building.
C608.4 Door swing. Vented wall furnaces shall be located so
that a door cannot swing within 12 inches (305 mm) of an air
inlet or air outlet of such furnace measured at right angles to the
opening. Doorstops or door closers shall not be installed to
obtain this clearance.
C608.5 Ducts prohibited. Ducts shall not be attached to wall
furnaces. Casing extension boots shall not be installed unless
Hsted as part of the appliance.
C608.6 Access. Vented wall furnaces shall be provided with
access for cleaning of heating surfaces, removal of burners,
replacement of sections, motors, controls, filters and other
working parts, and for adjustments and lubrication of parts
requiring such attention. Panels, grilles and access doors that
are required to be removed for normal servicing operations
shall not be attached to the building construction.
SECTION C609
FLOOR FURNACES
C609.1 General. Hoor furnaces shall be tested in accordance
with ANSI Z21.86/CSA 2.32 and shall be installed in accor-
dance with the manufacturer's installation instructions.
C609.2 Placement. The following provisions apply to floor
furnaces:
1 . Floors. Floor furnaces shall not be installed in the floor of
any doorway, stairway landing, aisle or passageway of
any enclosure, public or private, or in an exitway from
any such room or space.
2. Walls and comers. The register of a floor furnace with a
horizontal warm-air outlet shall not be placed closer than
2007 OREGON MECHANICAL SPECIALTY CODE
117.101
APPENDIX C
6 inches (152 mm) to the nearest wall. A distance of at
least 1 8 inches (457 mm) from two adjoining sides of the
floor furnace register to walls shall be provided to elimi-
nate the necessity of occupants walking over the
warm-air discharge. The remaining sides shall be per-
mitted to be placed not closer than 6 inches (152 mm) to a
wall. Wall-register models shall not be placed closer than
6 inches (152 mm) to a comer.
3. Draperies. The furnace shall be placed so that a door,
drapery or similar object cannot be nearer than 12 inches
(305 mm) to any portion of the register of the furnace.
4. Floor construction. Floor furnaces shall not be installed
in concrete floor construction built on grade.
5. Thermostat. The controlling thermostat for a floor fur-
nace shall be located within the same room or space as
the floor furnace or shall be located in an adjacent room
or space that is permanently open to the room or space
containing the floor furnace.
C609o3 Bracing. The floor around the furnace shall be braced
and headed with a support framework designed in accordance
with the Building Code.
C609.4 Clearance. The lowest portion of the floor furnace
shall have not less than a 6-inch (152 mm) clearance from the
grade level; except where the lower 6-inch (152 mm) portion of
the floor furnace is sealed by the manufacturer to prevent
entrance of water, the minimum clearance shall be not less than
2 inches (51 mm). Where such clearances cannot be provided,
the ground below and to the sides shall be excavated to form a
pit under the furnace so that the required clearance is provided
beneath the lowest portion of the furnace. A 12-inch (305 mm)
minimum clearance shall be provided on all sides except the
control side, which shall have an 18-inch (457 mm) minimum
clearance.
C609.S First floor installation. Where the basement story
level below the floor in which a floor furnace is installed is uti-
lized as habitable space, such floor furnaces shall be enclosed
as specified in Section C609.6 and shall project into a
nonhabitable space.
C6®9.6 Upper floor installations. Floor furnaces installed in
upper stories of buildings shall project below into nonhabitable
space and shall be separated from the nonhabitable space by an
enclosure constructed of noncombustible materials. The floor
furnace shall be provided with access, clearance to all sides and
bottom of not less than 6 inches (152 mm) and combustion air
in accordance with Section C304.
SECTION C610
DUCT FURNACES
C610.1 General. Duct furnaces shall be tested in accordance
with ANSI Z83.8 or UL 795 and shall be installed in accor-
dance with the manufacturer's installation instructions.
C610.2 Access panels. Ducts connected to duct furnaces shall
have removable access panels on both the upstream and down-
stream sides of the furnace.
C610.3 Location of draft Mood and controls. The controls,
combustion air inlets and draft hoods for duct furnaces shall be
located outside of the ducts. The draft hood shall be located in
the same enclosure from which combustion air is taken.
C610. 4 Circulating air. Where a duct furnace is installed so
that supply ducts convey air to areas outside the space contain-
ing the furnace, the return air shall also be conveyed by a
duct(s) sealed to the furnace casing and terminating outside the
space containing the furnace.
The duct furnace shall be installed on the positive pressure
side of the circulating air blower.
SECTION C611
NONRECIRCULATING D1RECT=F1RED
INDUSTRIAL AIR HEATERS
C611.1 General. Nonrecirculating direct-fired industrial air
heaters shall be listed to ANSI Z83.4/CSA 3.7 and shall be
installed in accordance with the manufacturer's instructions.
C611.2 Installation. Nonrecirculating direct-fired industrial
air heaters shall not be used to supply any area containing
sleeping quarters. Nonrecirculating direct-fired industrial air
heaters shall be installed only in industrial or commercial occu-
pancies. Nonrecirculating direct-fired industrial air heaters
shall be permitted to provide ventilation air.
C611.3 Clearance from combustible materials.
Nonrecirculating direct-fired industrial air heaters shall be
installed with a clearance from combustible materials of not
less than that shown on the rating plate and in the manufac-
turer's instructions.
C611.4 Supply air. All air handled by a nonrecirculating
direct-fired industrial air heater, including combustion air,
shall be ducted directly from the outdoors.
C611.5 Outdoor air louvers. If outdoor air louvers of either
the manual or automatic type are used, such devices shall be
proven to be in the open position prior to allowing the main
burners to operate.
C611.6 Atmospheric vents and gas reliefs oi
Nonrecirculating direct-fired industrial air heaters with valve
train components equipped with atmospheric vents or gas
reliefs or bleeds shall have their atmospheric vent lines or gas
reliefs or bleeds lead to the outdoors. Means shall be employed
on these lines to prevent water from entering and to prevent
blockage by insects and foreign matter. An atmospheric vent
line shall not be required to be provided on a valve train compo-
nent equipped with a listed vent limiter.
C611.7 Relief opening. The design of the installation shall
include provisions to permit nonrecirculating direct-fired
industrial air heaters to operate at rated capacity without
overpressurizing the space served by the heaters by taking into
account the structure's designed infiltration rate, providing
properly designed relief openings or an interlocked power
exhaust system, or a combination of these methods. The struc-
ture's designed infiltration rate and the size of relief openings
shall be determined by approved engineering methods. Relief
openings shall be permitted to be louvers or counterbalanced
gravity dampers. Motorized dampers or closable louvers shall
be permitted to be used, provided they are verified to be in their
full open position prior to main burner operation.
117.102
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
C611.8 Access. Nonrecirculating direct-fired industrial air
heaters shall be provided with access for removal of burners;
replacement of motors, controls, filters and other working
parts; and for adjustment and lubrication of parts requiring
maintenance.
C611.9 Purging. Inlet ducting, where used, shall be purged by
not less than four air changes prior to an ignition attempt.
SECTION C61 2
RECIRCULATING DIRECT-FIRED
INDUSTRIAL AIR HEATERS
C612.1 GeneraL Recirculating direct-fired industrial air heat-
ers shall be Hsted to ANSI Z83.18 and shall be installed in
accordance with the manufacturer's installation instructions.
C612.2 Location. Recirculating direct-fired industrial air
heaters shall be installed only in industrial and commercial
occupancies. Recirculating direct- fired air heaters shall not
serve any area containing sleeping quarters. Recirculating
direct-fired industrial air heaters shall not be installed in haz-
ardous locations or in buildings that contain flammable solids,
liquids or gases, explosive materials or substances that can
become toxic when exposed to flame or heat.
C612.3 Installation. Direct-fired industrial air heaters shall be
permitted to be installed in accordance with their listing and the
manufacturer's instructions. Directl-fired industrial air heaters
shall be installed only in industrial or commercial occupancies.
Direct-fired industrial air heaters shall be permitted to provide
fresh air ventilation.
C612.4 Clearance from combustible materials. Direct-fired
industrial air heaters shall be installed with a clearance from
combustible material of not less than that shown on the label
and in the manufacturer's instructions.
C612.5 Air supply. Air to direct-fired industrial air heaters
shall be taken from the building, ducted directly from outdoors,
or a combination of both. Direct-fired industrial air heaters
shall incorporate a means to supply outside ventilation air to
the space at a rate of not less than 4 cubic feet per minute per
1,000 Btu per hour (0.38 m^ per min per kW) of rated input of
the heater. If a separate means is used to supply ventilation air,
an interlock shall be provided so as to lock out the main burner
operation until the mechanical means is verified. Where out-
side air dampers or closing louvers are used, they shall be veri-
fied to be in the open position prior to main burner operation.
C612.6 Atmospheric vents, gas reliefs or bleeds. Direct-fired
industrial air heaters with valve train components equipped
with atmospheric vents, gas reliefs or bleeds shall have their
atmospheric vent lines and gas reliefs or bleeds lead to the out-
doors.
Means shall be employed on these lines to prevent water
from entering and to prevent blockage by insects and foreign
matter. An atmospheric vent line shall not be required to be pro-
vided on a valve train component equipped with a listed vent
limiter.
C612.7 Relief opening. The design of the installation shall
include adequate provision to permit direct-fired industrial air
heaters to operate at rated capabity by taking into account the
structure's designed infiltration rate, providing properly
designed relief openings or an interlocked power exhaust sys-
tem, or a combination of these methods. The structure's
designed infiltration rate and the size of relief openings shall be
determined by approved engineering methods. Relief openings
shall be permitted to be louvers or counterbalanced gravity
dampers. Motorized dampers or closable louvers shall be per-
mitted to be used, provided they are verified to be in their full
open position prior to main burner operation.
SECTION C613
CLOTHES DRYERS
C613.1 General. Clothes dryers shall be tested in accordance
with ANSI Z2 1.5.1 or ANSI Z21.5.2 and shall be installed in
accordance with the manufacturer's installation instructions
and Chapters.
SECTION C614
CLOTHES DRYER EXHAUST
C614.1 Installation. See Chapter 5, Section 504.
SECTION C615
SAUNA HEATERS
C615.1 General. Sauna heaters shall be installed in accor-
dance with the manufacturer's installation instructions and
Chapter 9.
C615.2 Combustion and dilution air intakes. Sauna heaters
of other than the direct- vent type shall be installed with the
draft hood and combustion air intake located outside the sauna
room. Where the combustion air inlet and the draft hood are in a
dressing room adjacent to the sauna room, there shall be provi-
sions to prevent physically blocking the combustion air inlet
and the draft hood inlet, and to prevent physical contact with
the draft hood and vent assembly, or warning notices shall be
posted to avoid such contact. Any warning notice shall be eas-
ily readable, shall contrast with its background and the wording
shall be in letters not less than V4 inch (6.4 mm) high.
C615.3 Combustion and ventilation air. Combustion air
shall not be taken from inside the sauna room. Combustion and
ventilation air for a sauna heater not of the direct- vent type shall
be provided to the area in which the combustion air inlet and
draft hood are located in accordance with Section C304.
SECTION C61 6
ENGINE AND GAS TURBINE-
POWERED EQUIPMENT
C616.1 Powered equipment. Permanently installed equip-
ment powered by internal combustion engines and turbines
shall be installed in accordance with the manufacturer's instal-
lation instructions and NFPA 37.
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2007 OREGON MECHANICAL SPECIALTY CODE
117.103
APPENDIX C
SECTION C617
POOL AND SPA HEATERS
C617.1 General, Pool and spa heaters shall be tested in accor-
dance with ANSI Z21.56 and shall be installed in accordance
with the manufacturer's installation instructions.
SECTION C618
ID-AIR WARM-AIR FURNACES
C618.1 General. Forced-air warm-air furnaces shall be tested
in accordance with ANSI Z21.47 or UL 795 and shall be
installed in accordance with the manufacturer's installation
instructions.
C618.2 Forced-air furnaces. The minimum unobstructed
total area of the outside and return air ducts or openings to a
forced-air warm-air furnace shall be not less than 2 square
inches for each 1,000 Btu/h (4402 mm^AV) output rating
capacity of the furnace and not less than that specified in the
furnace manufacturer's installation instructions. The minimum
unobstructed total area of supply ducts from a forced-air
warm-air furnace shall be not less than 2 square inches for each
1,000 Btu/h (4402 mm^AV) output rating capacity of the fur-
nace and not less than that specified in the furnace manufac-
turer's installation instructions.
Exception: The total area of the supply air ducts and outside
and return air ducts shall not be required to be larger than the
minimum size required by the furnace manufacturer's
installation instructions.
C618.3 Dampers. Volume dampers shall not be placed in the
air inlet to a furnace in a manner that will reduce the required air
to the furnace.
C618.4 Circulating air ducts for forced-air warm-air fur-
naces. Circulating air for fuel-burning, forced-air-type,
warm-air furnaces shall be conducted into the blower housing
from outside the furnace enclosure by continuous air-tight ducts.
C618.5 Prohibited sources. Outside or return air for a
forced-air heating system shall not be taken from the following
locations:
1. Closer than 10 feet (3048 mm) from an appliance vent
outlet, a vent opening from a plumbing drainage system
or the discharge outlet of an exhaust fan, unless the outlet
is 3 feet (914 mm) above the outside air inlet.
Exception: Listed outdoor appliances which provide
both circulating air and vent discharge.
2. Where there is the presence of objectionable odors,
fumes or flammable vapors; or where located less than
10 feet (3048 mm) above the surface of any abutting pub-
lic way or driveway; or where located at grade level by a
sidewalk, street, alley or driveway.
3. A hazardous or insanitary location or a refrigeration
machinery room as defined in this code.
4. A room or space, the volume of which is less than 25 per-
cent of the entire volume served by such system. Where
connected by a permanent opening having an area sized
in accordance with Section C618.2, adjoining rooms or
spaces shall be considered as a single room or space for
the purpose of determining the volume of such rooms or
spaces.
Exception." The minimum volume requirement shall
not apply where the amount of return air taken from a
room or space is less than or equal to the amount of
supply air delivered to such room or space.
5. A room or space containing an appliance where such a
room or space serves as the sole source of return air.
Exception: This shall not apply where:
1 . The appliance is a direct-vent appliance or an
appliance not requiring a vent in accordance
with Section 501.8.
2. The room or space complies with the following
requirements:
2.1. The return air shall be taken from a
room or space having a volume exceed-
ing 1 cubic foot for each 10 Btu/h (9.6
L/W) of combined input rating of all
fuel-burning appliances therein.
2.2. The volume of supply air discharged
back into the same space shall be
approximately equal to the volume of
return air taken from the space.
2.3. Return-air inlets shall not be located
within 10 feet (3048 mm) of any appU-
ance firebox or draft hood in the same
room or space.
3. Rooms or spaces containing solid fuel-burning
appliances, provided that return-air inlets are
located not less than 10 feet (3048 mm) from
the firebox of such appliances.
6. A. closet, bathroom, toilet room, kitchen, garage,
mechanical room, boiler room or furnace room.
C618.6 Screen. Required outdoor air inlets for residential por-
tions of a building shall be covered with a screen having
V4-inch (6.4 mm) openings. Required outdoor air inlets serving
a nonresidential portion of a building shall be covered with
screen having openings larger than V4 inch (6.4 mm) and not
larger than 1 inch (25 mm).
C618.7 Return-air limitation. Return air from one dwelling
unit shall not be discharged into another dwelling unit.
SECTION C61 9
CONVERSION BURNERS
C619.1 Conversion burners. The installation of conversion
burners shall conform to ANSI Z21.8.
SECTION C620
UNIT HEATERS
C620.1 General. Unit heaters shall be tested in accordance
with ANSI Z83.8 and shall be installed in accordance with the
manufacturer's installation instructions.
117.104
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
C620.2 Support. Suspended-type unit heaters shall be sup-
ported by elements that are designed and constructed to accom-
modate the weight and dynamic loads. Hangers and brackets
shall be of noncombustible material.
C620.3 Ductwork. Ducts shall not be connected to a unit
heater unless the heater is listed for such installation.
C620.4 Clearance. Suspended-type unit heaters shall be
installed with clearances to combustible materials of not less
than 1 8 inches (457 mm) at the sides, 12 inches (305 mm) at the
bottom and 6 inches (152 mm) above the top where the unit
heater has an internal draft hood or 1 inch (25 mm) above the
top of the sloping side of the vertical draft hood.
Floor-mounted-type unit heaters shall be installed with
clearances to combustible materials at the back and one side
only of not less than 6 inches (152 mm). Where the flue gases
are vented horizontally, the 6-inch (152 mm) clearance shall be
measured from the draft hood or vent instead of the rear wall of
the unit heater. Floor-mounted-type unit heaters shall not be
installed on combustible floors unless listed for such installa-
tion.
Clearances for servicing all unit heaters shall be in accor-
dance with the manufacturer's installation instructions.
Exception: Unit heaters listed for reduced clearance shall
be permitted to be installed with such clearances in accor-
dance with their listing and the manufacturer's instructions.
SECTION C621
UNVENTED ROOM HEATERS
C621.1 General. Unvented room heaters shall be tested in
accordance with ANSI Z2 1 . 11 .2 and shall be installed in accor-
dance with the conditions of the listing and the manufacturer's
installation instructions. Unvented room heaters utilizing fuels
other than fuel gas shall be regulated by the Mechanical Code.
C621.2 Prohibited use. One or more unvented room heaters
shall not be used as the sole source of comfort heating in a
dwelling unit.
C621.3 Input rating. Unvented room heaters shall not have an
input rating in excess of 40,000 Btu/h (11.7 Kw).
C621.4 Prohibited locations. Unvented room heaters shall not
be installed within occupancies in Groups A, E and I. The loca-
tion of unvented room heaters shall also comply with Section
C303.3.
C621.5 Room or space volume. The aggregate input rating of
all unvented appliances installed in a room or space shall not
exceed 20 Btu/h per cubic foot (207 W/m^) of volume of such
room or space. Where the room or space in which the equip-
ment is installed is directly connected to another room or space
by a doorway, archway or other opening of comparable size
that cannot be closed, the volume of such adjacent room or
space shall be permitted to be included in the calculations.
C621.6 Oxygen-depletion safety system. Unvented room
heaters shall be equipped with an oxygen-depletion-sensitive
safety shutoff system. The system shall shut off the gas supply
to the main and pilot burners when the oxygen in the surround-
ing atmosphere is depleted to the percent concentration speci-
fied by the manufacturer, but not lower than 1 8 percent. The
system shall not incorporate field adjustment means capable of
changing the set point at which the system acts to shut off the
gas supply to the room heater.
C621.7 Unvented decorative room heaters. An unvented
decorative room heater shall not be installed in a factory-built
fireplace unless the fireplace system has been specifically
tested, listed and labeled for such use in accordance with UL
127.
C621.7.1 Ventless firebox enclosures. Ventless firebox
enclosures used with unvented decorative room heaters
shall be listed as complying with ANSI Z2I.91.
SECTION C622
VENTED ROOM HEATERS
C622.1 General. Vented room heaters shall be tested in accor-
dance with ANSI Z21.86/CSA 2.32, shall be designed and
equipped as specified in Section C602.2 and shall be installed
in accordance with the manufacturer's installation instructions.
SECTION C623
COOKING APPLIANCES
C623.1 Cooking appliances. Cooking appliances that are
designed for permanent installation, including ranges, ovens,
stoves, broilers, grills, fryers, griddles, hot plates and barbe-
cues, shall be tested in accordance with ANSI Z21.1, ANSI
Z21.58 or ANSI Z83.ll and shall be installed in accordance
with the manufacturer's installation instructions.
C623.2 Prohibited location. Cooking appliances designed,
tested, listed and labeled for use in commercial occupancies
shall not be installed within dwelling units or within any area
where domestic cooking operations occur.
C623.3 Domestic appliances. Cooking appliances installed
within dwelling units and within areas where domestic cooking
operations occur shall be listed and labeled as household-type
appliances for domestic use.
C623.4 Domestic range installation. Domestic ranges
installed on combustible floors shall be set on their own bases
or legs and shall be installed with clearances of not less than
that shown on the label.
C623.4.1 Installation of a listed cooking appliance or
microwave over a listed cooking top appliance. The
installation of a listed cooking appliance or microwave oven
over a hsted cooking top appliance shall conform to the con-
ditions of the upper appliance's hsting and the manufac-
turer's installation instructions.
C623.5 Open-top broiler unit hoods. A ventilating hood shall
be provided above a domestic open-top broiler unit, unless oth-
erwise listed for forced down draft ventilation.
C623.5.1 Clearances. A minimum clearance of 24 inches
(C610 mm) shall be maintained between the cooking top
and combustible material above the hood. The hood shall be
at least as wide as the open-top broiler unit and be centered
over the unit.
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2007 OREGON MECHANICAL SPECIALTY CODE
117.105
APPENDIX C
SECTION C624
ERHE^
C624.1 General Water heaters shall be tested in accordance
withANSIZ21.10.1 and ANSIZ21. 10.3 and shall be installed
in accordance with the manufacturer's installation instructions
Water heaters utilizing fuels other than fuel gas shall be regu-
lated by Chapter 10.
C624.1.1 lestallatioe requiremeints. The requirements for
water heaters relative to sizing, relief valves, drain pans and
scald protection shall be in accordance with the Plumbing
Code.
C624.2 Walter heaters utilized! for space heating. Water heat-
ers utilized both to supply potable hot water and provide hot
water for space-heating applications shall be listed and labeled
for such applications by the manufacturer and shall be installed
in accordance with the manufacturer's installation instmctions,
this code and the Plumbing Code.
SECTION C625
REFRIGERATORS
C62S.1 General, Refrigerators shall be tested in accordance
with ANSI Z21 . 19 and shall be installed in accordance with the
manufacturer's installation instructions.
Refrigerators shall be provided with adequate clearances for
ventilation at the top and back, and shall be installed in accor-
dance with the manufacturer's instructions. If such instructions
are not available, at least 2 inches (5 1 mm) shall be provided
between the back of the refrigerator and the wall and at least 12
inches (305 mm) above the top.
GAS-F8RED TOILETS
C626,l General, Gas-fired toilets shall be tested in accordance
with ANSI Z21.61 and installed in accordance with the manu-
facturer's installation instructions.
C626.2 Clearance. A gas-fired toilet shall be installed in
accordance with its listing and the manufacturer's instructions,
provided that the clearance shall in any case be sufficient to
afford ready access for use, cleanout and necessary servicing.
SECTION C627
A!R=C0NDmONING EQUIPMENT
C627.1 General. Gas-fired air-conditioning equipment shall
be tested in accordance with ANSI Z2 1 .40. 1 or ANSI Z2 1 .40.2
and shall be installed in accordance with the manufacturer's
installation instructions.
C627,2 Independent piping. Gas piping serving heating
equipment shall be permitted to also serve cooling equipment
where such heating and cooling equipment cannot be operated
simultaneously (see Section C402).
C627,3 Connection of gas engine-powered air conditioners.
To protect against the effects of normal vibration in service, gas
engines shall not be rigidly connected to the gas supply piping.
C627,4 Clearances for indoor installation. Air-conditioning
equipment installed in rooms other than alcoves and closets
shall be installed with clearances not less than those specified
in Section C308.3 except that air-conditioning equipment
listed for installation at lesser clearances than those specified in
Section C308.3 shall be permitted to be installed in accordance
with such listing and the manufacturer's instructions and
air-conditioning equipment listed for installation at greater
clearances than those specified in Section C308.3 shall be
installed in accordance with such listing and the manufac-
turer's instructions.
Air-conditioning equipment installed in rooms other than
alcoves and closets shall be permitted to be installed with
reduced clearances to combustible material, provided that the
combustible material is protected in accordance with Table
C308.2.
C627.5 Alcove and closet installation. Air-conditioning
equipment installed in spaces such as alcoves and closets shall
be specifically listed for such installation and installed in
accordance with the terms of such listing. The installation
clearances for air-conditioning equipment in alcoves and clos-
ets shall not be reduced by the protection methods described in
Table C308.2.
C627,6 Installation. Air-conditioning equipment shall be
installed in accordance with the manufacturer's instructions.
Unless the equipment is listed for installation on a combustible
surface such as a floor or roof, or unless the surface is protected
in an approved manner, equipment shall be installed on a sui"-
face of noncombustible construction with noncombustible
material and surface finish and with no combustible material
against the underside thereof.
C627,7 Plenums and air ducts. A plenum supplied as a part of
the air-conditioning equipment shall be installed in accordance
with the equipment manufacturer's instructions. Where a ple-
num is not supplied with the equipment, such plenum shall be
installed in accordance with the fabrication and installation
instructions provided by the plenum and equipment manufac-
turer. The method of connecting supply and return ducts shall
facilitate proper circulation of air.
Where air-conditioning equipment is installed within a
space separated from the spaces served by the equipment, the
air circulated by the equipment shall be conveyed by ducts that
are sealed to the casing of the equipment and that separate the
circulating air from the combustion and ventilation air.
C627.8 Refrigeration coils. A refrigeration coil shall not be
installed in conjunction with a forced-air furnace where circu-
lation of cooled air is provided by the furnace blower, unless
the blower has sufficient capacity to overcome the external
static resistance imposed by the duct system and cooling coil at
the air throughput necessary for heating or cooling, whichever
is greater. Furnaces shall not be located upstream from cooling
units, unless the cooling unit is designed or equipped so as not
to develop excessive temperature or pressure. Refrigeration
coils shall be installed in parallel with or on the downstream
side of central furnaces to avoid condensation in the heating
element, unless the furnace has been specifically listed for
downstream installation. With a parallel flow aiTangement, the
dampers or other means used to control flow of air shall be suf-
117.106
2007 OREGON MECHANJCAL SPECIALTY CODE
APPENDIX C
ficiently tight to prevent any circulation of cooled air through
the furnace.
Means shall be provided for disposal of condensate and to
prevent dripping of condensate onto the heating element.
C627.9 Cooling units used with heating boilers. Boilers,
where used in conjunction with refrigeration systems, shall be
installed so that the chilled mediuni is piped in parallel with the
heating boiler with appropriate valves to prevent the chilled
medium from entering the heating boiler. Where hot water
heating boilers are connected to heating coils located in
air-handling units where they might be exposed to refrigerated
air circulation, such boiler piping systems shall be equipped
with flow control valves or other automatic means to prevent
gravity circulation of the boiler water during the cooling cycle.
C627.10 Switches in electrical supply line. Means for inter-
rupting the electrical supply to the: air-conditioning equipment
and to its associated cooling tower (if supplied and installed in a
location remote from the air coriditioner) shall be provided
within sight of and not over 50 feet (15 240 nam) from the air
conditioner and cooling tower.
SECTION G628
ILLUMINATING APPLIANCES
General. Illuminating appliances shall be tested in
accordance with ANSI Z21.42 and; shall be installed in accor-
dance with the manufacturer's installation instructions.
C628.2 Mounting on buildings. Illuminating appliances
designed for wall or ceiling miDunting shall be securely
attached to substantial structures in such a manner that they are
not dependent on the gas piping for support.
C628.3 Mounting on posts. Illuminating appliances designed
for post mounting shall be securely and rigidly attached to a
post. Posts shall be rigidly mounted. The strength and rigidity
of posts greater than 3 feet (914 mm) in height shall be at least
equivalent to that of a 2V2-inch-diameter (64 mm) post con-
structed of 0.064-inch-thick (1.6-mm) steel or a 1-inch (25.4
mm) Schedule 40 steel pipe. Posts 3 feet (914 mm) or less in
height shall not be smaller than a V4-inch (19.1 mm) Schedule
40 steel pipe. Drain openings shall be provided near the base of
posts where there is a possibility of water collecting inside
them.
C628.4 Appliance pressure regulators. Where an appliance
pressure regulator is not supplied ;with an illuminating appli-
ance and the service line is not equipped with a service pressure
regulator, an appliance pressure regulator shall be installed in
the line to the illuminating appliance. For multiple installa-
tions, one regulator of adequate capacity shall be permitted to
serve more than one illuminating appliance.
SECTION C629
SMALL CERAMIC KILNS
C629.1 General, Ceramic kilns with a maximum interior vol-
ume of 20 cubic feet (0.566 m^) and used for hobby and non-
commercial purposes shall be installed in accordance with the
manufacturer's installation instructions and the provisions of
this code.
C629.2 Unlisted fuel-gas kiln installation. Unlisted fuel-gas
kilns shall be installed in accordance with the manufacturer's
installation instructions and the provisions of this appendix.
C629.2.1 Clearances for interior installation. The sides
and tops of kilns shall be located a minimum of 1 8 inches
(457 mm) from any noncombustible wall surface and 3 feet
(914 mm) from any combustible wall surface. Kilns shall be
installed on noncombustible flooring, consisting of at least
2 inches (5 1 mm) of solid masonry or concrete extending at
least 12 inches (305 mm) beyond the base or supporting
members of the kiln.
Exception: These clearances may be reduced, provided
independent testing is provided to and approved by the
building official.
C629.2.2 Control side clearance. The clearance on the
control side of a kiln shall not be reduced to less than 30
inches (762 mm).
C629.2.3 Hoods. A canopy type hood shall be installed
directly above each kiln. The face opening area of the hood
shall be equal to or greater than the top horizontal surface
area of the kiln. The hood shall be constructed of not less
than 0.030-inch (0.76 mm) (No. 22 U.S. gauge) galvanized
steel or equivalent and be supported at a height of between
12 inches and 30 inches (305 mm and 762 mm) above the
kiln by noncombustible supports.
Exception: Electric kilns installed with listed exhaust
blowers may be used when marked as being suitable for
the kiln and installed in accordance with manufacturer's
instructions.
C629.2.4 Gravity ventilation ducts. Each kiln hood shall
be connected to a gravity ventilation duct extending in a ver-
tical direction to outside the building. This duct shall be of
the same construction as the hood and shall have a
cross-sectional area of not less than one-fifteenth of the face
opening of the hood. The duct shall terminate a minimum of
12 inches (305 mm) above any portion of a building within 4
feet (1219 mm) and terminate no less than 4 feet (1219 mm)
from any openable windows or other opening into the build-
ing or adjacent property line. The duct connected to the out-
side shall be shielded, without reduction of duct area, to
prevent entrance of rain into the duct. The duct shall be sup-
ported at each section by noncombustible supports.
C629.2.5 Hood and duct clearances. Every hood and duct
serving a fuel-gas burning kiln shall have a clearance from
combustible construction of at least 18 inches (457 mm). This
clearance may be reduced in accordance with Table C308.2.
C629.2.5.1 Makeup air. Provisions shall be made for air
to enter the room in which a kiln is installed at a rate at
least equal to the air being removed through the kiln hood.
C629.3 Exterior installations. Kilns shall be installed with
minimum clearances as specified in Section C629.2.2. Kilns
located under a roof and enclosed by two or more vertical wall
surfaces, shall have a hood and gravity ventilation duct installed
to comply with Sections C629.2.4, C629.2.5 and C629.2.6.
2007 OREGON MECHANICAL SPECIALTY CODE
117.107
APPENDIX C
IMFRARED RADIANT HEATERS
C630.1 GeeeraL Infrared radiant heaters shall be tested in
accordance with ANSI Z83.6 and shall be installed in accor-
dance with the manufacturer's installation instructions.
SECTION C634
GASEOUS HYDROGEN SYSTEMS
C634.1 Installation, The installation of gaseous hydrogen
systems shall be in accordance with the applicable require-
ments of this code, the Fire Code and the Building Code.
L2 Sepport. Infrared radiant heaters shall be fixed in a
position independent of gas and electric supply lines. Hangers
and brackets shall be of noncombustible material.
>
>
BOILERS
C631.1 StandardSo Boilers shall be listed in accordance with
Chapter 10.
C631.2 Clearance to combustilble materials. Clearances to
combustible materials shall be in accordance with Section
> C308.4.
SECTION C632
STATIONARY FUEL-CELL POWER SYSTEMS
C632.1 General. Stationary fuel-cell power systems having a
power output not exceeding 10 MW shall be tested in accor-
dance with ANSI CSA America FC 1 and shall be installed in
accordance with the manufacturer's installation instructions
andNFPA853.
SECTION C633
CHIMNEY DAMPER OPENING AREA
C633.1 Free opening area of chimney dampers. Where an
unlisted decorative appliance for installation in a vented fire-
place is installed, the fireplace damper shall have a permanent
free opening equal to or greater than specified in Table C633. 1 .
SECTION C701
GENERAL
C701.1 Scope. The installation of gaseous hydrogen systems
shall comply with this chapter and Chapters 30 and 35 of the
Fire Code. Compressed gases shall also comply with Chapter
27 of the Fire Code for general requirements.
C701.2 Permits. Permits shall be required as set forth in Sec-
tion 106 and as required by the Fire Code.
SECTION C702
GENERAL DEFINITIONS
C702.1 Definitions. The following words and terms shall, for
the purposes of this chapter and as used elsewhere in this code,
have the meanings shown herein.
HYDROGEN CUTOFF ROOM. A room or space which is
intended exclusively to house a gaseous hydrogen system.
HYDROGEN-GENERATING APPLIANCE. A self-con-
tained package or factory-matched packages of integrated sys-
tems for generating gaseous hydrogen. Hydrogen-generating
appliances utilize electrolysis, reformation, chemical or other
processes to generate hydrogen.
GASEOUS HYDROGEN SYSTEM. An assembly of piping,
devices and apparatus designed to generate, store, contain, dis-
tribute or transport a nontoxic, gaseous hydrogen containing
mixture having at least 95 -percent hydrogen gas by volume and
not more than 1 -percent oxygen by volume. Gaseous hydrogen
systems consist of items such as compressed gas containers,
reactors and appurtenances, including pressure regulators,
pressure relief devices, manifolds, pumps, compressors and
interconnecting piping and tubing and controls.
TABLE C633.1
FREE OPENING AREA OF CHIMNEY DAMPER FOR VENTING FLUE GASES
FROM UNLISTED DECORATIVE APPLIANCES FOR INSTALLATION IN VENTED FIREPLACES
CHIMNEY HEIGHT
(feet)
MINIMUM PERMANENT FREE OPENING (square inches)'
8
13
20
29
39
51
64
Appliance input rating (Btu per liour)
6
. 7,800
14,000
23,200
34,000
46,400
62,400
80,000
8
8,400
15,200
25,200
37,000
50,400
68,000
86,000
10
9,000
16,800
27,600
40,400
55,800
74,400
96,400
15
9,800
18,200
30,200
44,600
62,400
84,000
108,800
20
10,600
20,200
32,600
50,400
68,400
94,000
122,200
30
11,200
21,600
36,600
55,200
76,800
105,800
138,600
For SI: 1 inch = 25.4 mm, 1 foot - 304.8 mm, 1 square inch = 645.16m^ 1 British thermal unit per hour = 0.2931 W.
117.108
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
SECTION C703
GENERAL REQUIREMENTS
C703.1 Hydrogen-generating and refueling operations.
Ventilation shall be required in accordance with Section
C703.1.1, C703.1.2 or C703.1.3 in public garages, private
garages, repair garages, automotive motor fuel-dispensing
facilities and parking garages that contain hydrogen-generat-
ing appliances or refueling systems. For the purpose of this sec-
tion, rooms or spaces that are not part of the living space of a
dwelling unit and that communicate directly with a private
garage through openings shall be considered to be part of the
private garage.
C703.1.1 Natural ventilation. Indoor locations intended
for hydrogen-generating or refueling operations shall be
limited to a maximum floor area of 850 square feet (79 m^)
and shall communicate with the outdoors in accordance
with Sections C703. 1.1.1 and C703.1.1.2. The maximum
rated output capacity of hydrogen generating appliances
shall not exceed 4 standard cubic feet per minute (0.00189
mVs) of hydrogen for each 250 square feet (23.2 m^) of floor
area in such spaces. The minimum cross- sectional dimen-
sion of air openings shall be 3 inches (76 mm). Where ducts
are used, they shall be of the same cross-sectional area as the
free area of the openings to which they connect. In such
locations, equipment and appliances having an ignition
source shall be located such that the source of ignition is not
within 12 inches (305 mm) of the ceiling.
C703.1.1.1 Two openings. Two permanent openings
shall be provided within the garage. The upper opening
shall be located entirely within 12 inches (305 mm) of the
ceiling of the garage. The lower opening shall be located
entirely within 12 inches (305 mm) of the floor of the
garage. Both openings shall be provided in the same
exterior wall. The openings shall communicate directly
with the outdoors and shall have a minimum free area of
V2 square foot per 1,000 cubic feet (1 mV610 m^) of
garage volume.
C703.1.1.2 Louvers and grilles. In calculating the free
area required by Section C703 .1.1.1, the required size of
openings shall be based on the net free area of each open-
ing. If the free area through a design of louver or grille is
known, it shall be used in calculating the size opening
required to provide the free area specified. If the design
and free area are not known, it shall be assumed that
wood louvers will have 25 -percent free area and metal
louvers and grilles will have 75 -percent free area. Lou-
vers and grilles shall be fixed in the open position.
C703.1.2 Mechanical ventilation. Indoor locations
intended for hydrogen-generating or refueling operations
shall be ventilated in accordance with Section 502.16. In
such locations, equipment and appliances having an igni-
tion source shall be located such that the source of ignition is
below the mechanical ventilation outlet(s).
C703.1.3 Specially engineered installations. As an alter-
native to the provisions of Section C703.1.1 and C703.1.2,
the necessary supply of air for ventilation and dilution of
flammable gases shall be provided by an approved engi-
neered system.
C703.2 Containers, cylinders and tanks. Compressed gas
containers, cylinders and tanks shall comply with Chapters 30
and 35 of the Fire Code.
C703.2.1 Limitations for indoor storage and use. Flam-
mable gas cylinders in occupancies regulated by the Oregon
Residential Specialty Code shall not exceed 250 cubic feet
(7.1 m^) at normal temperature and pressure (NTP).
C703.2.2 Design and construction. Compressed gas con-
tainers, cylinders and tanks shall be designed, constructed
and tested in accordance with the Chapter 27 of the Fire
Code, ASME Boiler and Pressure Vessel Code (Section
VIII) or DOTn 49 CFR, Parts 100-180.
C703.3 Pressure relief devices. Pressure relief devices shall
be provided in accordance with Sections C703.3.1 through
C703.3.8. Pressure relief devices shall be sized and selected in
accordance with CGA S-1.1, CGA S-1.2 and CGA S-1.3.
C703.3.1 Valves between pressure relief devices and con-
tainers. Valves including shu toffs, check valves and other
mechanical restrictions shall not be installed between the
pressure relief device and container being protected by the
relief device.
Exception: A locked-open shutoff valve on containers
equipped with multiple pressure-relief device installa-
tions where the arrangement of the valves provides the
full required flow through the minimum number of
required relief devices at all times.
C703.3.2 Installation. Valves and other mechanical restric-
tions shall not be located between the pressure relief device
and the point of release to the atmosphere.
C703.3.3 Containers. Containers shall be provided with
pressure relief devices in accordance with the ASME Boiler
and Pressure Vessel Code (Section VIII), DOTn 49 CFR,
Parts 100-180 and Section C703.3.7.
C703.3.4 Vessels other than containers. Vessels other
than containers shall be protected with pressure relief
devices in accordance with the ASME Boiler and Pressure
Vessel Code (Section VIII), or DOTn 49 CFR, Parts
100-180.
C703.3.5 Sizing. Pressure relief devices shall be sized in
accordance with the specifications to which the container
was fabricated. The relief device shall be sized to prevent the
maximum design pressure of the container or system from
being exceeded.
C703.3.6 Protection. Pressure relief devices and any asso-
ciated vent piping shall be designed, installed and located so
that their operation will not be affected by water or other
debris accumulating inside the vent or obstructing the vent.
C703.3.7 Access. Pressure relief devices shall be located
such that they are provided with ready access for inspection
and repair.
C703.3.8 Configuration. Pressure relief devices shall be
arranged to discharge unobstructed in accordance with Sec-
tion 2209 of the Fire Code. Discharge shall be directed to the
outdoors in such a manner as to prevent impingement of
escaping gas on personnel, containers, equipment and adja-
2007 OREGON MECHANICAL SPECIALTY CODE
117.109
APPENDIX C
cent structures and to prevent introduction of escaping gas
into enclosed spaces. The discharge shall not terminate
under eaves or canopies.
Exception: This section shall not apply to DOTn-speci-
fied containers with an internal volume of 2 cubic feet
(0.057 m^) or less.
C703o4 Venting. Relief device vents shall be terminated in an
approved location in accordance with Section 2209 of the Fire
Code.
C703.S Security. Compressed gas containers, cylinders, tanks
and systems shall be secured against accidental dislodgement
in accordance with Chapter 30 of the Fire Code.
C703.6 Electrical wiring and equipment. Electrical wiring
and equipment shall comply with the Electrical Code.
SECTION C704
PIPING, USE AND HANDLING
C704,l Applicability. Use and handling of containers, cylin-
ders, tanks and hydrogen gas systems shall comply with this
section. Gaseous hydrogen systems, equipment and machinery
shall be listed or approved.
€704.1,1 Controls. Compressed gas system controls shall
be designed to prevent materials from entering or leaving
process or reaction systems at other than the intended time,
rate or path. Automatic controls shall be designed to be fail
safe in accordance with accepted engineering practice.
C704.1.2 Piping systems. Piping, tubing, valves and fit-
tings conveying gaseous hydrogen shall be designed and
installed in accordance with Sections C704. 1.2.1 through
C704. 1.2.5.1, Chapter 27 of the Fire Code, and ASME
B3 1 .3. Cast-iron pipe, valves and fittings shall not be used.
C704.1.2.1 Sizing. Gaseous hydrogen piping shall be
sized in accordance with approved engineering methods.
C704. 1.2.2 Identification of hydrogen piping systems.
Hydrogen piping systems shall be marked in accordance
with ANSI A 13.1. Markings used for piping systems
shall consist of the name of the contents and shall include
a direction-of-flow arrow. Markings shall be provided at
all of the following locations:
1 . At each valve.
2. At wall, floor and ceiling penetrations.
3. At each change of direction.
4. At intervals not exceeding 20 feet (6096 mm).
C704.1.2.3 Piping design and construction. Piping and
tubing materials shall be 300 series stainless steel or
materials listed or approved for hydrogen service and the
use intended through the full range of operating condi-
tions to which they will be subjected. Piping systems
shall be designed and constructed to provide allowance
for expansion, contraction, vibration, settlement and fire
exposure.
C704,1.2,3.1 Prohibited locations. Piping shall not
be installed in or through a circulating air duct;
clothes chute; chimney or gas vent; ventilating duct;
dumbwaiter; or elevator shaft. Piping shall not be
concealed or covered by the surface of any wall, floor
or ceihng.
C704.1.2.3.2 Interior piping. Except for through
penetrations, piping located inside of buildings shall
be installed in exposed locations and provided with
ready access for visual inspection.
C704. 1.2.3.3 Underground piping. Underground
piping, including joints and fittings, shall be protected
from corrosion and installed in accordance with
approved engineered methods.
C704.1.2.3.4 Piping througl
Underground piping shall not penetrate the outer
foundation or basement wall of a building.
C704.1.2,3.5 Protection against physical damage.
In concealed locations, where piping other than stain-
less steel piping, stainless steel tubing or black steel is
installed through holes or notches in wood studs,
joists, rafters or similar members less than 1.5 inches
(38 mm) from the nearest edge of the member, the
pipe shall be protected by shield plates. Shield plates
shall be a minimum of '/,6-inch- thick (1.6 mm) steel,
shall cover the area of the pipe where the member is
notched or bored and shall extend a minimum of 4
inches (102 mm) above sole plates, below top plates
and to each side of a stud, joist or rafter.
C704.1.2.3.6 Piping outdoors. Piping installed
above ground, outdoors, shall be securely supported
and located where it will be protected from physical
damage. Piping passing through an exterior wall of a
building shall be encased in a protective pipe sleeve.
The annular space between the piping and the sleeve
shall be sealed from the inside such that the sleeve is
ventilated to the outdoors. Where passing through an
exterior wall of a building, the piping shall also be
protected against corrosion by coating or wrapping
with an inert material. Below-ground piping shall be
protected against corrosion.
C704.1.2,3.7 Settlement. Piping passing through
concrete or masonry walls shall be protected against
differential settlement.
C704. 1.2.4 Joints. Joints in piping and tubing in hydro-
gen service shall be listed as complying with ASME
B31.3 to include the use of welded, brazed, flared,
socket, slip and compression fittings. Gaskets and seal-
ants used in hydrogen service shall be listed as comply-
ing with ASME B31.3. Threaded and flanged
connections shall not be used in areas other than hydro-
gen cutoff rooms and outdoors.
C704.1.2.4.1 Brazed joints. Brazing alloys shall
have a melting point greater than 1,000°F (538°C).
C704.1.2.4.2 Electrical contimuity. Mechanical
joints shall maintain electrical continuity through
the joint or a bonding jumper shall be installed
around the joint.
117.110
2007 OREGON WIECHANICAL SPECIALTY CODE
APPENDIX C
C704.1.2.5 Valves and piping components. Valves,
regulators and piping components shall be listed or
approved for hydrogen service, shall be provided with
access and shall be designed and constructed to with-
stand the maximum pressure to which such components
will be subjected.
C704.1.2.5.1 Shutoff valves on storage containers
and tanks. Shutoff valves shall be provided on all
storage container and tank connections except for
pressure relief devices. Shutoff valves shall be pro-
vided with ready access.
C704.2 Upright use. Compressed gas containers, cylinders
and tanks, except those with a water volume less than 1.3 gal-
lons (5 L) and those designed for use in a horizontal position,
shall be used in an upright position with the valve end up. An
upright position shall include conditions where the container,
cylinder or tank axis is inclined as much as 45 degrees (0.79
rad) from the vertical.
C704.3 Material-specific regulations. In addition to the
requirements of this section, indoor and outdoor use of hydro-
gen compressed gas shall comply with the material-specific
provisions of Chapters 30 and 35 of the Fire Code.
C704.4 Handling. The handling of compressed gas contain-
ers, cylinders and tanks shall comply with Chapter 27 of the
Fire Code.
SECTION C705
TESTING OF HYDROGEN PIPING SYSTEMS
C705.1 General. Prior to acceptance and initial operation, all
piping installations shall be inspected and pressure tested to
determine that the materials, design fabrication and installa-
tion practices comply with the requirements of this code.
C705.2 Inspections. Inspections shall consist of a visual
examination of the entire piping system installation and a
pressure test. Hydrogen piping systems shall be inspected in
accordance with this code. Inspection methods such as out-
lined in ASME B31.3 shall be permitted where specified by
the design engineer and approved by the code official. Inspec-
tions shall be conducted or verified by the code official prior
to system operation.
C705.3 Pressure tests. A hydrostatic or pneumatic leak test
shall be performed. Testing of hydrogen piping systems shall
utilize testing procedures identified in ASME B31.3 or other
approved methods, provided that the testing is performed in
accordance with the minimum provisions specified in Sec-
tions C705.3.1 through C705.4.1.
C705.3.1 Hydrostatic leak tests. The hydrostatic test
pressure shall be not less than one-and-one-half times the
maximum working pressure, and not less than 100 psig
(689.5 kPa gauge).
C705.3.2 Pneumatic leak tests. The pneumatic test pres-
sure shall be not less than one-and-one-half times the max-
imum working pressure for systems less than 125 psig
(862 kPa gauge) and not less than 5 psig (34.5 kPa gauge),
whichever is greater. For working pressures at or above
125 psig (862 kPa gauge), the pneumatic test pressure shall
be not less than 1 10 percent of the maximum working pres-
sure.
C705.3.3 Test limits. Where the test pressure exceeds 125
psig (862 kPa gauge), the test pressure shall not exceed a
value that produces hoop stress in the piping greater than
50 percent of the specified minimum yield strength of the
pipe.
C705.3.4 Test medium. Deionized water shall be utilized
to perform hydrostatic pressure testing and shall be
obtained from a potable source. The medium utilized to
perform pneumatic pressure testing shall be air, nitrogen,
carbon dioxide or an inert gas; oxygen shall not be used.
C705.3.5 Test duration. The minimum test duration shall
be '/j hour. The test duration shall be not less than Vj hour
for each 500 cubic feet (14.2 m^) of pipe volume or fraction
thereof. For piping systems having a volume of more than
24,000 cubic feet (680 m^), the duration of the test shall not
be required to exceed 24 hours. The test pressure required
in Sections C705.3.I and C705.3.2 shall be maintained for
the entire duration of the test.
C705.3.6 Test gauges. Gauges used for testing shall be as
follows:
1. Tests requiring a pressure of 10 psig (68.95 kPa
gauge) or less shall utilize a testing gauge having
increments of 0.10 psi (0.6895 kPa) or less.
2. Tests requiring a pressure greater than 10 psig
(68.98 kPa gauge) but less than or equal to 100 psig
(689.5 kPa gauge) shall utilize a testing gauge hav-
ing increments of 1 psi (6.895 kPa) or less.
3. Tests requiring a pressure greater than 100 psig
(689.5 kPa gauge) shall utilize a testing gauge hav-
ing increments of 2 psi (13.79 kPa) or less.
Exception: Measuring devices having an equivalent
level of accuracy and resolution shall be permitted
where specified by the design engineer and approved by
the code official.
C705.3.7 Test preparation. Pipe joints, including welds,
shall be left exposed for examination during the test.
C705.3.7.1 Expansion joints. Expansion joints shall
be provided with temporary restraints, if required, for
the additional thrust load under test.
C705.3.7.2 Equipment disconnection. Where the pip-
ing system is connected to appliances, equipment or
components designed for operating pressures of less
than the test pressure, such appliances, equipment and
components shall be isolated from the piping system by
disconnecting them and capping the outlet(s).
C705.3.7.3 Equipment isolation. Where the piping
system is connected to appliances, equipment or com-
ponents designed for operating pressures equal to or
greater than the test pressure, such appliances, equip-
ment and components shall be isolated from the piping
system by closing the individual appliance, equipment
or component shutoff valve(s).
2007 OREGON MECHANICAL SPECIALTY CODE
117.111
APPENDIX C
C7©5.4 DetecMom of leaks and defects. The piping system
shall withstand the test pressure specified for the test duration
specified without showing any evidence of leakage or other
defects. Any reduction of test pressures as indicated by pres-
sure gauges shall indicate a leak within the system. Piping
systems shall not be approved except where this reduction in
pressure is attributed to some other cause.
C70S.4.1 Corrections. Where leakage or other defects are
identified, the affected portions of the piping system shall
be repaired and retested.
C7(Ili5.5 Purging of gaseous hydrogen piping systems. Purg-
ing shall comply with Sections C705.5.1 through C705.5.4.
C705.5.1 Removal from service. Where piping is to be
opened for servicing, addition or modification, the section
to be worked on shall be isolated from the supply at the
nearest convenient point and the line pressure vented to the
outdoors. The remaining gas in this section of pipe shall be
displaced with an inert gas.
C705.5.2 Placing in operation. Prior to placing the sys-
tem into operation, the air in the piping system shall be dis-
placed with inert gas. The inert gas flow shall be continued
without interruption until the vented gas is free of air. The
inert gas shall then be displaced with hydrogen until the
vented gas is free of inert gas. The point of discharge shall
not be left unattended during purging. After purging, the
vent opening shall be closed.
C70S.S.3 Discharge of purged gases. The open end of
piping systems being purged shall not discharge into con-
fined spaces or areas where there are sources of ignition
except where precautions are taken to perform this opera-
tion in a safe manner by ventilation of the space, control
of purging rate and elimination of all hazardous condi-
tions.
C705.5.3.1 Vent pipe outlets for purging. Vent pipe
outlets for purging shall be located such that the inert
gas and fuel gas is released outdoors and not less than 8
feet (2438 mm) above the adjacent ground level. Gases
shall be discharged upward or horizontally away from
adjacent walls to assist in dispersion. Vent outlets shall
be located such that the gas will not be trapped by eaves
or other obstructions and shall be at least 5 feet (1524
mm) from building openings and lot lines of properties
that can be built upon.
C705.5.4 Placing equipment in operation. After the pip-
ing has been placed in operation, all equipment shall be
purged in accordance with Section C707.2 and then placed
in operation, as necessary.
C7(06.2 Indoor gaseous hydrogen systems. Gaseous hydro-
gen systems shall be located in indoor rooms or areas in accor-
dance with one of the following:
1 . Inside a building in a hydrogen cutoff room designed
and constructed in accordance with Section 420 of the
Building Code;
2. Inside a building not in a hydrogen cutoff room where
the gaseous hydrogen system is listed and labeled for
indoor installation and installed in accordance with the
manufacturer's installation instructions; and
3. Inside a building in a dedicated hydrogen fuel dispens-
ing area having an aggregate hydrogen delivery capac-
ity not greater than 12 SCFM and designed and
constructed in accordance with Section C703.1.
C706.3 Outdoor gaseous hydrogen systems. Gaseous
hydrogen systems shall be located outdoors in accordance
with Section 2209.3.2 of the Fire Code.
SECTION C707
OPERATION AND MAINTENANCE OF
GASEOUS HYDROGEN SYSTEMS
C707.1 Maintenance. Gaseous hydrogen systems and detec-
tion devices shall be maintained in accordance with the Fire
Code and the manufacturer's installation instructions.
C707.2 Purging. Purging of gaseous hydrogen systems, other
than piping systems purged in accordance with Section
C705.5, shall be in accordance with Section 221 1.8 of the Fire
Code or in accordance with the system manufacturer's instruc-
tions.
SECTION C708
DESIGN OF LIQUEFIED HYDROGEN SYSTEMS
ASSOCIATED WITH HYDROGEN
VAPORIZATION OPERATIONS
C708.1 General. The design of liquefied hydrogen systems
shall comply with Chapter 32 of the Fire Code
SE«
LOCATION OF GASEOUS HYDROGEN SYSTEMS
C706.1 General. The location and installation of gaseous
hydrogen systems shall be in accordance with Sections
C706.2andC706.3.
Exception: Stationary fuel-cell power plants in accor-
dance with Section C633.
117.112
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
SECTION C-8
REFERENCED STANDARDS
This section lists the standards that are referenced in various sections of Appendix C. The standards are listed herein by the
promulgating agency of the standard, the standard identification, the effective date and title, and the section or sections of
Appendix C that reference the standard. The application of the referenced standards shall be as specified in Section CI 02. 8 of
this code.
ANSI
Standard
Referenced
reference
in code
number
Title
section number
ANSI A13. 1-96
ANSI CS A- America FC 1-03
LC 1—97
Z21.1— 03
Z21.5.1— 02
Z21.5.2— 01
Z21.8— 94(R2002)
Z21.10.1— 04
Z21.10.3— 01
Z21.1 1.2—02
Z21.13— 04
Z21.15— 97(R2003)
Z21.19— 02
Z2 1.24— 97
Z2 1.40.1— 96 (R2002)
Z2 1.40.2— 96 (R2002)
Z21.42— 93(R2002)
Z2 1.47— 03
Z2 1.50— 03
Z2 1.56— 01
Z21.58— 95(R2002)
Z2 1.60— 03
Z21.61— 83(R1996)
Z2 1.69— 02
Z21.75/CSA 6.27—01
Z2 1.80— 03
Z2 1.84— 02
Z2 1.86— 04
Z2 1.88— 02
Z2 1.9 1—01
Z83.4— 03
Z83.6— 90(R1998)
Z83.8— 02
Z83.ll— 02
Z83.18— 00
American National Standards Institute
25 West 43rd Street
Fourth Floor
New York, NY 10036
Title
Scheme for the Identification of piping systems C704. 1.2.2
Stationery Fuel Cell Power Systems C633.1
Interior Gas Piping Systems Using Corrugated Stainless Steel Tubing with Addenda LCla-1999 and LClb-2001 C403.5.4
Household Cooking Gas Appliances with Addenda Z2 1 . 1 a-2003 and Z2 1 . 1 b-2003 C623 . 1
Gas Clothes Dryers - Volume I -Type 1 Clothes Dryers with Addenda Z21.5. la-2003 C613.1
Gas Clothes Dryers - Volume II- Type 2 Clothes Dryers with Addenda Z21.5.2a-2003 and Z21.5.2b-2003 C613.1, C614.3
Installation of Domestic Gas Conversion Burners C619.1
Gas Water Heaters - Volume I - Storage, Water Heaters with Input Ratings of 75,000 Btu per Hour or Less -
with Addenda Z21.10.1a-2002 C624.1
Gas Water Heaters - Volume III - Storage, Water Heaters with Input Ratings Above 75,000 Btu per hour.
Circulating and Instantaneous - with Addenda Z21.10.3a-2003 and Z21.10.3b-2004 C624.1
Gas-fired Room Heaters - Volume II - Unvented Room Heaters with Addenda Z2 1 . 1 1 .2a-2003 C621.1
Gas-fired Low-Pressure Steam and Hot Water Boilers C631.1
Manually Operated Gas Valves for Appliances, Appliance Connector Valves, and Hose End Valves with
Addenda Z21.15a-2001(R2003) C409.1.1
Refrigerators Using Gas (R1999) Fuel. C625.1
Connectors for Gas Apphances C41 1.1
Gas-fired' Heat Activated Air Conditioning and Heat Pump Appliances— with Addendum Z2 1.40. la- 1997 (R2002) . . C627.1
Gas-fired Work Activated Air Conditioning and Heat Pump Appliances (Internal Combustion) — with
Addendum Z21.40.2a-97 (R2002) C627.1
Gas-fired Illuminating Appliances C628. 1
Gas-fired Central Furnaces C618.1
Vented Gas Fireplaces - with Addenda Z21.50a-2003 C604.1
Gas-fired Pool Heaters - with Addenda Z21.56a-2004 and Z21.56b-2004 C616.1
Outdoor Cooking Gas Appliances— with Addendum Z21.58a-1998 (R2002) and Z21.58b-2002 C623.1
Decorative Gas Appliances for Installation in Solid- fuel Burning Fireplaces - with Addenda Z2 1.60a- 2003 C602.1
Toilets, Gas-Fired C625.1
Connectors for Movable Gas Appliances - with Addenda Z21 .69a- 2003 C41 1 . 1
Connectors for Outdoor Gas Appliances and Manufactured Homes C41 1.1, C41 1.2
Line Pressure Regulators C410.1
Manually-Lighted, Natural Gas Decorative Gas Appliances for Installation in
Solid Fuel Burning Fireplaces - with Addenda Z21.84a-2003 C602.1, C602.2
Gas-Fired Vented Space Heating Apphances - with Addenda Z21.86a-2002 and Z21.86b-2002 C608.1, C609.1, C622.1
Vented Gas Fireplace Heaters with Addenda Z21.88a-2003 and Z21.88b-2004 C605.1
Ventiess Firebox Enclosures for Gas-Fired Unvented Decorative Room Heaters C62 1.7.1
Non-Recirculating Direct-Gas-Fired Industrial Air Heaters C61 1.1
Gas-Fired Infrared Heaters C630. 1
Gas Unit Heaters and Gas-Fired Duct Furnaces - with Addenda Z83.8a-2003 C620.1
Gas Food Service Equipment - with Addenda Z83.1 la-2004 C623.1
Recirculating Direct Gas-Fired Industrial Air Heaters with Addenda Z83.18a 2001 and Z83.18b-2003 C612.1
2007 OREGON MECHANICAL SPECIALTY CODE
117.113
APPENDIX C
American Society of Meciianical Engineers
Three Park Avenue
New Yorif, NY 10016-5990
Standard
Referenced
reference
in code
number
Title
section number
Bl.20.1— 83 (Reaffirmed 2001) Pipe Threads, General Purpose (inch) C403.9
B 16. 1—98
B 16.20— 98
B3 1.3-02
B16.33— 02
B 16.44-01
B31.3— 99
B36.10M— 00
BPVC— 01
CSD-1— 02
Cast Iron Pipe Flanges and Flanged Fittings, Class 25, 125 and 250 C403.12
Metallic Gaskets for Pipe Flanges Ring-joint, Spiral-wound, and Jacketed — with Addendum B16.20a-2000 C403.12
Process Piping C704.1.2.4, C704.12, C705.2, C705.3
Manually Operated Metallic Gas Valves for Use in Gas Piping Systems up to 125 psig (Sizes V2 through 2) C409. 1 . 1
Manually Operated Metallic Gas Valves for Use in House Piping Systems C409. 1.1
Process Piping C704.1.2, C705.2, C705.3
Welded and Seamless Wrought-steel Pipe C403.4.2
ASME Boiler & Pressure Vessel Code (2001 Edition) (Section I, II, IV, V & IX) C630.1, C703.2.2, C703.3.3, C703.3.4
Controls and Safety Devices for Automatically Fired Boilers C631.1
A 53/A 53M— 02
A 106—04
A 254—97 (2002)
A 539—99
B88— 03
B 210— 02
B 241/B 241M— 02
B 280— 03
C 64—72 (1977)
C 315—02
D 25 13— 04a
ASTM International
100 Barr Harbor Drive
West Conshohocken, PA 19428-2959
Standard
Referenced
reference
in code
number
Title
section number
Specification for Pipe, Steel, Black and Hot Dipped Zinc-coated Welded and Seamless
Specification for Seamless Carbon Steel Pipe for High-temperature Service
Specification for Copper Brazed Steel Tubing
Specification for Electric Resistance-welded Coiled Steel Tubing for Gas and Fuel Oil Lines
Specification for Seamless Copper Water Tube
Specification for Aluminum and Aluminum-alloy Drawn Seamless Tubes
Specification for Aluminum and Aluminum-alloy, Seamless Pipe and Seamless Extruded Tube
Specification for Seamless Copper Tube for Air Conditioning and Refrigeration Field Service
Withdrawn No Replacement (Specification for Fireclay Brick Refractories for
Heavy Duty Stationary Boiler Service)
Specification for Clay Flue Linings
Specification for Thermoplastic Gas Pressure Pipe, Tubing, and Fittings C403.6, C403.6.1,
C403.4.2
C403.4.2
C403.5.1
...C403.5.1
C403.5.2
C403.5.3
C403.4.4, C403.5.3
C403.5.2
C503. 10.2.5
C501.12
C403.ll, C404.14.2
American Water Works Association
6666 West Quincy Avenue
Denver, CO 80235
Standard
reference
number
Title
Referenced
in code
section number
cm— 00
Rubber-Gasket Joints for Ductile-iron Pressure Pipe and Fittings C403.r2
Compressed Gas Association
1725 Jefferson Davis Highway, 5th Floor
Arlington, VA 22202-4102
Referenced
in code
Title _^ section number
Pressure Relief Device Standards — Part 1 — Cylinders for Compressed Gases C703.3
Pressure Relief Device Standards — Part 2 — Cargo and Portable Tanks for Compressed Gases C703.3
Pressure Relief Device Standards — Part 3 — Stationary Storage Containers for Compressed Gases C703.3
Standard
reference
number
S-1.1— (2002)
S- 1.2— (1995)
S-1.3— (1995)
117.114
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C
CSA America Inc.
f^ C A ^501 E. Pleasant Valley Rd.
V^t3r\. Cleveland. OH USA 44131-5575
Standard Referenced
reference in code
Part number Title section number
ANSI CSA America FCl-03 Stationary Fuel Cell Power Systems C633.1
CSA Requirement 3-88 Manually Operated Gas Valves for Use in House Piping Systems C409.1.1
CSA 8 — 93 Requirements for Gas-fired Log Lighters for Wood Burning Fireplaces with Revisions through January 1999 C603.1
DOTn
Department of Transportation
400 Seventh St. SW.
Washington, DC 20590
Standard
reference
number
Title
Referenced
in code
section number
49CFR,Parts 192.281(e) &
192.283 (b)
49 CFR Parts 100-180
Transportation of Natural and Other Gas by Pipeline: Minimum Federal Safety Standards .
Hazardous Materials Regulations
C403.6.1
.C703.2.2, C703.3.3, C703.3.4
ICC
IBC— 06
ICC EC— 06
lEBC— 06
lECC— 06
IFC— 06
IMC— 06
IPC— 06
IRC— 06
International Code Council
500 New Jersey Ave, NW
6th Floor
Washington, DC 20001
Standard
Referenced
reference
in code
number
Tide
section number
International Building Code® : C102.2.1, C20L3, C301.10, C301.ll, C301.12, C301.14, C302.1, C302.2,
C305.6, C306.6, C401.1.1, C412.6, C413.3, C413.3.1, C501.1, C501,3, C501.12,
C501.15.4, C609.3, C614.2, C706.1, C706.3
International Code Council Electrical Code Administrative Provisions ... C201 .3, C306.3.1 , C306.4.1, C306.5.2, C309.2,
C413.8.2.4, C703.6
International Existing Building Code C101.2
International Energy Conservation Code C301.2
International Fire Code® C201.3, C303.4, C401.2, C412.1, C412.6, C412.7, C412.7.3, C412.8,
C413.I, C413.3, C413.3.1, C413.4, C413.8.2.5, C701.1, C701.2, C703.2, C703.2.2,
C703.3.8, C703.4, C703.5, C704.1.2, C704.3, C704.4, C706.2, C706.3.4, C706.3.5, C706.3.6, C707.2, C707.1, C708.1
International Mechanical Code® ClOl.2.5, C201.3, C301.1.1, C301.13, C304.ll, C501.1,
C614.2, C618.5, C621.1, C624.1, C631.2, C632.1, C703.1.2, C706.3.2
International Plumbing Code® C201.3, C301.6, C624.1.1, C624.2
International Residential Code C703.2.1
MSS
Manufacturers Standardization Society of
the Valve and Fittings Industry
127 Park Street, Northeast
Vienna, VA 22180
Standard
reference
number
Title
Referenced
in code
section number
SP-6— 01
SP-58— 93
Standard Finishes for Contact Faces of Pipe Flanges and Connecting-end Flanges of Valves and Fittings .
Pipe Hangers and Supports — Materials, Design and Manufacture
.C403.12
. .C407.2
NFPA
National Fire Protection Association
1 Batterymarch Pike
P.O. Box 9101
Quincy, MA 02269-9101
Standard
reference
number
Title
Referenced
in code
section number
30A-03
37—02
Code for Motor Fuel Dispensing Facilities and Repair Garages
Installation and Use of Stationary Combustion Engines and Gas Turbines.
.C305.5
.C616.1
2007 OREGON MECHANICAL SPECIALTY CODE
117.115
APPEMDDX C
50A— 99
51—02
58—04
82—04
85—04
211—03
853—03
NFPA — continued
Gaseous Hydrogen Systems at Consumer Sites C706.1
Design and Installation of Oxygen-Fuel Gas Systems for Welding, Cutting, and Allied Processes C414.1
Liquefied Petroleum Gas Code C401.2, C402.6.1, C403.6.2, C403.1 1
Incinerators, Waste and Linen Handling Systems and Equipment C607.1
Boiler and Combustion Systems Hazards Code C631. 1
Chimneys, Fireplaces, Vents, and Solid Fuel-burning Appliances C503.5.2, C503.5.3, C503.5.6.1, C503.5.6.3
Installation of Stationary Fuel Cell Power Systems C633.1
Underwriters Laboratories Inc.
333 Pfingsten Road
Northbrook, IL 60062
Referenced
in code
Title '_ section number
Factory-built Chimneys, Residential Type and Building Heating Appliances -
with Revisions through December 2003 C506. 1
Factory-built Fireplaces — with Revisions through November 1999 C621.7
Gas Vents — with Revisions through December 1999 C502. 1
Type L Low-temperature Venting Systems — with Revisions through April 1999 C502. 1
Schedule 40 and Schedule 80 Rigid PVC Conduit and Fittings C403.6.3
Commercial-Industrial Gas Heating Equipment C610.1, C618.1, C631 .1
Medium Heat Appliance Factory-built Chimneys C506.3
Venting Systems for Gas Burning Appliances, Categories 11, III and IV with
Revisions through December 2000 C502.1
Standard for Chimney Liners C501.12, C501.15.4
Standard
reference
number
103—2001
127—99
441—96
641—95
651—05
795—99
959—01
1738—00
1777—04
117.116
2007 OREGON MECHANICAL SPECBALTY CODE
APPENDIX C-A
SIZING AND CAPACITIES OF GAS PIPING
(This appendix is informative and is not part of the code.)
C-A.l General. To determine the size of piping used in a gas
piping system, the following factors must be considered:
(1) Allowable loss in pressure from point of delivery to
equipment
(2) Maximum gas demand
(3) Length of piping and number of fittings
(4) Specific gravity of the gas
(5) Diversity factor
For any gas piping system, or special gas utilization equip-
ment, or for conditions other than those covered by the tables
provided in this code, such as longer runs, greater gas demands,
or greater pressure drops, the size of each gas piping system
should be determined by standard engineering practices ac-
ceptable to the code official.
C- A,2 Description of tables
C-A.2.1 General. The quantity of gas to be provided at each
outlet should be determined, whenever possible, directly from
the manufacturer's British thermal unit (Btu) input rating of the
equipment that will be installed. In case the ratings of the
equipment to be installed are not known. Table C402.2 shows
the approximate consumption (in Btu per hour) of certain types
of typical household appliances.
To obtain the cubic feet per hour of gas required, divide the
total Btu input of all equipment by the average Btu heating
value per cubic feet of the gas. The average Btu per cubic feet of
the gas in the area of the installation can be obtained from the
serving gas supplier.
C-A.2.2 Low pressure natural gas tables. Capacities for gas
at low pressure [0.5 psig (3.5 kPa gauge) or less] in cubic feet
per hour of 0.60 specific gravity gas for different sizes and
lengths are shown in Tables C402.4(l) and C402.4(2) for iron
pipe or equivalent rigid pipe, in Tables C402.4(7) through
C402.4(9) for smooth wall semi-rigid tubing, and in Tables
C402.4(14) through C402.4(16) for corrugated stainless steel
tubing. Tables C402.4(l) and C402.4(7) are based upon a pres-
sure drop of 0.3-inch water column (w.c.) (75 Pa), whereas Ta-
bles C402.4(2), C402.4(8) and C402.4(14) are based upon a
pressure drop of 0.5-inch w.c. (125 Pa). Tables C402.4(9),
C402.4(15) and C402.4(16) are special low-pressure applica-
tions based upon pressure drops greater than 0.5-inch w.c. (125
Pa). In using these tables, an allowance (in equivalent length of
pipe) should be considered for any piping run with four or more
fittings [see Table C-A.2.2].
C-A.2.3 Undiluted liquefied petroleum tables. Capacities in
thousands of Btu per hour of undiluted liquefied petroleum
gases based on a pressure drop of 0.5 -inch w.c. (125 Pa) for dif-
ferent sizes and lengths are shown in Table C402.4(24) for iron
pipe or equivalent rigid pipe, in Table C402.4(26) for smooth
wall semi-rigid tubing, in Table C402.4(28) for corrugated
stainless steel tubing, and in Tables C402.4(31) and
C402.4(33) for polyethylene plastic pipe and tubing. Tables
C402.4(29) and C402.4(30) for corrugated stainless steel tub-
ing and Table C402.4(32) for polyethylene plastic pipe are
based on operating pressures greater than 0.5 pounds per
square inch (psi) (3.5 kPa) and pressure drops greater than
0.5-inch w.c. (125 Pa). In using these tables, an allowance (in
equivalent length of pipe) should be considered for any piping
run with four or more fittings [see Table C-A.2.2].
C-A.2.4 Natural gas specific gravity. Gas piping systems that
are to be supplied with gas of a specific gravity of 0.70 or less
can be sized directly from the tables provided in this code, un-
less the code ofiicial specifies that a gravity factor be applied.
Where the specific gravity of the gas is greater than 0.70, the
gravity factor should be applied.
Application of the gravity factor converts the figures given in
the tables provided in this code to capacities for another gas of
different specific gravity. Such application is accomplished by
multiplying the capacities given in the tables by the multipliers
shown in Table C-A.2.4. In case the exact specific gravity does
not appear in the table, choose the next higher value specific
gravity shown.
TABLE C-A.2.4
MULTIPLIERS TO BE USED WITH TABLES C402.4(1)
THROUGH C402.4(21) WHERE THE SPECIFIC GRAVITY
OF THE GAS IS OTHER THAN 0.60
SPECIFIC
GRAVITY
MULTIPLIER
SPECIFIC
GRAVITY
MULTIPLIER
.35
1.31
1.00
.78
.40
1.23
1.10
.74
.45
1.16
1.20
.71
.50
1.10
1.30
.68
.55
1.04
1.40
.66
.60
1.00
1.50
.63
.65
.96
1.60
.61
.70
.93
1.70
.59
.75
.90
1.80
.58
.80
.87
1.90
.56
.85
.84
2.00
.55
.90
.82
2.10
.54
2007 OREGON MECHANICAL SPECIALTY CODE
117.117
APPENDIX C-A
TABLE C-A.2.2
EQUIVALENT LENGTHS OF PIPE FITTINGS AND VALVES
SCREWED FITTINGS^
90° WELDING ELBOWS AND SiVIOOTH BENDS^
45°/Ell
90°/E0
180° dose
return
bends
Tee
R/d=l
R/d = IV3
R/d = 2
R/d = 4
R/d = 6
R/d = S
/f factors
0.42
0.90
2.00
1.80
0.48
0.36
0.27
0.21
0.27
0.36
t/d' ratio" n =
14
30
67
60
16
12
9
7
9
12
Nominal
pipe size,
inches
Inside
diameter d,
inches,
Schedule 40^
L = Equivalent Length In Feet of Schedule 40 (Standard-Weight) Straight Pipe
6
V2
0.622
0.73
1.55
3.47
3.10
0.83
0.62
0.47
0.36
0.47
0.62
%
0.824
0.96
2.06
4.60
4.12
1.10
0.82
0.62
0.48
0.62
0.82
1
1.049
1.22
2.62
5.82
5.24
1.40
1.05
0.79
0.61
0.79
1.05
IV4
1.380
1.61
3.45
7.66
6.90
1.84
1.38
1.03
0.81
1.03
1.38
IV,
1.610
1.88
4.02
8.95
8.04
2.14
1.61
1.21
0.94
1.21
1.61
2
2.067
2.41
5.17
11.5
10.3
2.76
2.07
1.55
1.21
1.55
2.07
2'/,
2.469
2.88
6.16
13.7
12.3
3.29
2.47
1.85
1.44
1.85
2.47
3
3.068
3.58
7.67
17.1
15.3
4.09
3.07
2.30
1.79
2.30
3.07
4
4.026
4.70
10.1
22.4
20.2
5.37
4.03
3.02
2.35
3.02
4.03
5
5.047
5.88
12.6
28.0
25.2
6.72
5.05
3.78
2.94
3.78
5.05
6
6.065
7.07
15.2
33.8
30.4
8.09
6.07
4.55
3.54
4.55
6.07
8
7.981
9.31
20.0
44.6
40.0
10.6
7.98
5.98
4.65
5.98
7.98
10
10.02
11.7
25.0
55.7
50.0
13.3
10.0
7.51
5.85
7.51
10.0
12
11.94
13.9
29.8
66.3
59.6
15.9
11.9
8.95
6.96
8.95
11.9
14
13.13
15.3
32.8
73.0
65.6
17.5
13.1
9.85
7.65
9.85
13.1
16
15.00
17.5
37.5
83.5
75.0
20.0
15.0
11.2
8.75
11.2
15.0
18
16.88
19.7
42.1
93.8
84.2
22.5
16.9
12.7
9.85
12.7
16.9
20
18.81
22.0
47.0
105.0
94.0
25.1
18.8
14.1
11.0
14.1
18.8
24
22.63
26.4
56.6
126.0
113.0
30.2
22.6
17.0
13.2
17.0
22.6
continued
117.118
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C-A
TABLE C-A.2.2— continued
EQUIVALENT LENGTHS OF PIPE FITTINGS AND VALVES
MITER ELBOWS' (No
of miters)
WELDING TEES
VALVES (screwed, flanged, or welded)
1-45°
1-60°
1-90°
2.90=5
3-90°®
Forged
Miter'
Gate
Globe
Angle
Swing
Check
k factor =
0.45
0.90
1.80
0.60
0.45
1.35
1.80
0.21
10
5.0
2.5
Ud' ratio* n =
15
30
60
20
15
45
60
7
333
167
83
Nominal
pipe size,
inclies
Inside
diameter d,
inciies,
Schedule 40®
L = Equivalent Length In Feet of Schedule 40 (Standard-Weight) Straight Pipe®
%
0.622
0.78
1.55
3.10
• 1.04
0.78
2.33
3.10
0.36
17.3
8.65
4.32
%
0.824
1.03
2.06
4.12
1.37
1.03
3.09
4.12
0.48
22.9
11.4
5.72
1
1.049
1.31
2.62
5.24
1.75
1.31
3.93
5.24
0.61
29.1
14.6
7.27
l'/4
1.380
1.72
3.45
6.90
2.30
1.72
5.17
6.90
0.81
38.3
19.1
9.58
IV,
1.610
2.01
4.02
8.04
2.68
2.01
6.04
8.04
0.94
44.7
22.4
11.2
2
2.067
2.58
5.17
10.3
3.45
2.58
7.75
10.3
1.21
57.4
28.7
14.4
2'/2
2.469
3.08
6.16
12.3
4.11
3.08
9.25
12.3
1.44
68.5
34.3
17.1
3
3.068
3.84
7.67
15.3
5.11
3.84
11.5
15.3
1.79
85.2
42.6
21.3
4
4.026
5.04
10.1
20.2
6.71
5.04
15.1
20.2
2.35
112.0
56.0
28.0
5
5.047
6.30
12.6
25.2
8.40
6.30
18.9
25.2
2.94
140.0
70.0
35.0
6
6.065
7.58
15.2
30.4
10.1
7.58
22.8
30.4
3.54
168.0
84.1
42.1
8
7.981
9.97
20.0
40.0
13.3
9.97
29.9
40.0
4.65
222.0
111.0
55.5
10
10.02
12.5
25.0
50.0
16.7
12.5
37.6
50.0
5.85
278.0
139.0
69.5
12
11.94
14.9
29.8
59.6
19.9
14.9
44.8
59.6
6.96
332.0
166.0
83.0
14
13.13
16.4
32.8
65.6
21.9
16.4
49.2
65.6
7.65
364.0
182.0
91.0
16
15.00
18.8
37.5 ■
75.0
25.0
18.8
56.2
75.0
8.75
417.0
208.0
104.0
18
16.88
21.1
42.1
84.2
28.1
21.1
63.2
84.2
9.85
469.0
234.0
117.0
20
18.81
23.5
47.0
94.0
31.4
23.5
70.6
94.0
11.0
522.0
261.0
131.0
24
22.63
28.3
56.6
113.0
37.8
28.3
85.0
113.0
13.2
629.0
314.0
157.0
For SI: 1 foot = 305 mm, 1 degree = 0.01745 rad.
Note: Values for welded fittings are for conditions where bore is not obstructed by weld spatter or backing rings. If appreciably obstructed, use values for "Screwed
Fittings."
1. Flanged fittings have three-fourths the resistance of screwed elbows and tees.
2. Tabular figures give the extra resistance due to curvature alone to which should be added the full length of travel.
3. Small size socket- welding fittings ai-e equivalent to miter elbows and miter tees.
4. Equivalent resistance in number of diameters of straight pipe computed for a value of (f- 0.0075) from the relation (n - k/4f).
5. For condition of minimum resistance where the centerline length of each miter is between d and 2^/2d.
6. For pipe having other inside diameters, the equivalent resistance may be computed from the above n values.
Source: Crocker, S. Piping Handbook, 4th ed., Table XIV, pp. 100-101 . Copyright 1945 by McGraw-Hill, Inc. Used by permission of McGraw-Hill Book Company.
2007 OREGON MECHANICAL SPECIALTY CODE
117.119
APPENDIX C-A
C-A.2.5 Higher pressure natural gas tables. Capacities for
gas at pressures greater than 0.5 psig (3.5 kPa gauge) in cubic
feet per hour of 0.60 specific gravity gas for different sizes and
lengths are shown in Tables C402.4(3) through C402.4(6) for
iron pipe or equivalent rigid pipe, Tables C402.4(10) to
C402.4(13) for semi-rigid tubing. Tables C402.4(17) and
C402.4(18) for corrugated stainless steel tubing, and Tables
C402.4(19) through C402.4(21) for polyethylene plastic pipe.
C-A,3 Use of capacity tables
C-A.3.1 Longest length method. This sizing method is con-
servative in its approach by applying the maximum operating
conditions in the system as the norm for the system and by set-
ting the length of pipe used to size any given part of the piping
system to the maximum value.
To determine the size of each section of gas piping in a sys-
tem within the range of the capacity tables, proceed as follows,
(also see sample calculations included in this Appendix).
(1) Divide the piping system into appropriate segments
consistent with the presence of tees, branch lines and
main runs. For each segment, determine the gas load
(assuming all appliances operate simultaneously) and
its overall length. An allowance (in equivalent length of
pipe) as determined from Table C-A.2.2 shall be con-
sidered for piping segments that include four or more
fittings.
(2) Determine the gas demand of each appliance to be at-
tached to the piping system. Where Tables C402.4(l)
through C402.4(23) are to be used to select the piping
size, calculate the gas demand in terms of cubic feet per
hour for each piping system outlet. Where Tables
C402.4(24) through C402.4(33) are to be used to select
the piping size, calculate the gas demand in terms of
thousands of Btu per hour for each piping system out-
let.
(3) Where the piping system is for use with other than un-
diluted liquefied petroleum gases, determine the design
system pressure, the allowable loss in pressure
(pressure drop), and specific gravity of the gas to be
used in the piping system.
(4) Determine the length of piping from the point of deliv-
ery to the most remote outlet in the building/piping sys-
tem.
(5) In the appropriate capacity table, select the row
showing the measured length or the next longer length
if the table does not give the exact length. This is the
only length used in determining the size of any section
of gas piping. If the gravity factor is to be applied, the
values in the selected row of the table are multiplied by
the appropriate multiplier from Table C-A.2.4.
(6) Use this horizontal row to locate ALL gas demand fig-
ures for this particular system of piping.
(7) Starting at the most remote outlet, find the gas demand
for that outlet in the horizontal row just selected. If the
exact figure of demand is not shown, choose the next
larger figure left in the row.
(8) Opposite this demand figure, in the first row at the top,
the correct size of gas piping will be found.
(9) Proceed in a similar manner for each outlet and each
section of gas piping. For each section of piping, deter-
mine the total gas demand supplied by that section.
When a large number of piping components (such as elbows,
tees and valves) are installed in a pipe run, additional pressure
loss can be accounted for by the use of equivalent lengths. Pres-
sure loss across any piping component can be equated to the
pressure drop through a length of pipe. The equivalent length of
a combination of only four elbows/tees can result in a jump to
the next larger length row, resulting in a significant reduction in
capacity. The equivalent lengths in feet shown in Table C-A.2.2
have been computed on a basis that the inside diameter corre-
sponds to that of Schedule 40 (standard-weight) steel pipe,
which is close enough for most purposes involving other
schedules of pipe. Where a more specific solution for equiva-
lent length is desired, this may be made by multiplying the ac-
tual inside diameter of the pipe in inches by n/12, or the actual
inside diameter in feet by n (n can be read from the table head-
ing). The equivalent length values can be used with reasonable
accuracy for copper or brass fittings and bends although the re-
sistance per foot of copper or brass pipe is less than that of steel.
For copper or brass valves, however, the equivalent length of
pipe should be taken as 45 percent longer than the values in the
table, which are for steel pipe.
C-A.3.2 Branch length method. This sizing method reduces
the amount of conservatism built into the traditional Longest
Length Method. The longest length as measured from the me-
ter to the furthest remote appliance is only used to size the ini-
tial parts of the overall piping system. The Branch Length
Method is applied in the following manner:
(1) Determine the gas load for each of the connected
appliances.
(2) Starting from the meter, divide the piping system into a
number of connected segments, and determine the
length and amount of gas that each segment would
carry assuming that all appliances were operated
simultaneously. An allowance (in equivalent length of
pipe) as determined from Table C-A.2.2 should be con-
sidered for piping segments that include four or more
fittings.
(3) Determine the distance from the outlet of the gas meter
to the appliance furthest removed from the meter.
(4) Using the longest distance (found in Step 3), size each
piping segment from the meter to the most remote ap-
pliance outlet.
(5) For each of these piping segments, use the longest
length and the calculated gas load for all of the con-
nected appliances for the segment and begin the sizing
process in Steps 6 through 8.
(6) Referring to the appropriate sizing table (based on op-
erating conditions and piping material), find the longest
length distance in the first column or the next larger dis-
tance if the exact distance is not listed. The use of
alternative operating pressures and/or pressure drops
117.120
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C-A
will require the use of a different sizing table, but will
not alter the sizing methodology. In many cases, the use
of alternative operating pressures and/or pressure drops
will require the approval of both the code official and
the local gas serving utility.
(7) Trace across this row until the gas load is found or the
closest larger capacity if the exact capacity is not listed.
(8) Read up the table column and select the appropriate
pipe size in the top row. Repeat Steps 6, 7 and 8 for each
pipe segment in the longest run.
(9) Size each remaining section of branch piping not
previously sized by measuring the distance from the
gas meter location to the most remote outlet in that
branch, using the gas load of attached appliances and
following the procedures of Steps 2 through 8.
C-A.3.3 Hybrid pressure method. The sizing of a 2 psi (13.8
kPa) gas piping system is performed using the traditional
Longest Length Method but with modifications. The 2 psi
(13.8 kPa) system consists of two independent pressure zones,
and each zone is sized separately. The Hybrid Pressure Method
is applied as follows.
The sizing of the 2 psi (13.8 kPa) section (from the meter to
the line regulator) is as follows:
(1) Calculate the gas load (by adding up the name plate
ratings) from all connected appliances. (In certain
circumstances the installed gas load may be increased
up to 50 percent to accommodate future addition of ap-
pliances.) Ensure that the line regulator capacity is ade-
quate for the calculated gas load and that the required
pressure drop (across the regulator) for that capacity
does not exceed % psi (5.2 kPa) for a 2 psi (13.8 kPa)
system. If the pressure drop across the regulator is too
high (for the connected gas load), select a larger regula-
tor.
(2) Measure the distance from the meter to the line
regulator located inside the building.
(3) If there are multiple line regulators, measure the dis-
tance from the meter to the regulator furthest removed
from the meter.
(4) The maximum allowable pressure drop for the 2 psi
(13.8 kPa) section is 1 psi (6.9 kPa).
(5) Referring to the appropriate sizing table (based on pip-
ing material) for 2 psi (13.8 kPa) systems with a 1 psi
(6.9 kPa) pressure drop, find this distance in the first
column, or the closest larger distance if the exact dis-
tance is not listed.
(6) Trace across this row until the gas load is found or the
closest larger capacity if the exact capacity is not listed.
(7) Read up the table column to the top row and select the
appropriate pipe size.
(8) If there are multiple regulators in this portion of the
piping system, each line segment must be sized for its
actual gas load, but using the longest length previously
determined above.
The low pressure section (all piping downstream of the line
regulator) is sized as follows:
(1) Determine the gas load for each of the connected
appliances.
(2) Starting from the line regulator, divide the piping
system into a number of connected segments and/or in-
dependent parallel piping segments, and determine the
amount of gas that each segment would carry assuming
that all appliances were operated simultaneously. An
allowance (in equivalent length of pipe) as determined
from Table C-A.2.2 should be considered for piping
segments that include four or more fittings.
(3) For each piping segment, use the actual length or lon-
gest length (if there are sub-branchlines) and the calcu-
lated gas load for that segment and begin the sizing
process as follows:
(a) Referring to the appropriate sizing table (based
on operating pressure and piping material), find
the longest length distance in the first column or
the closest larger distance if the exact distance is
not listed. The use of alternative operating pres-
sures and/or pressure drops will require the use of
a different sizing table, but will not alter the sizing
methodology. In many cases, the use of alterna-
tive operating pressures and/or pressure drops
may require the approval of the code official.
(b) Trace across this row until the appliance gas load is
found or the closest larger capacity if the exact ca-
pacity is not listed.
(c) Read up the table column to the top row and select
the appropriate pipe size.
(d) Repeat this process for each segment of the piping
system.
C-A.4 Use of sizing equations. Capacities of smooth wall
pipe or tubing can also be determined by using the following
formulae:
(1) High Pressure [1.5 psi (10.3 kPa) and above]:
2=181.6.
= 223>1D'
C, fba-L
C-L
2007 OREGON MECHANICAL SPECIALTY CODE
117.121
APPENDIX C-A
(2) Low Pressure [Less than L5 psi (10.3 kPa)]:
2=187.3
2313D'
D' AH
C ^ ■ fba-L
AH
C-L
where:
Q = Rate, cubic feet per hour at 60°F and 30-inch mercury
column
D = Inside diameter of pipe, in.
Pj = Upstream pressure, psia
P2 = Downstream pressure, psia
Y = Superexpansibility factor = 1/supercompressibiHty factor
Cr = Factor for viscosity, density and temperature*
= 0.00354 ST
Note: See Table 402.4 for Y and C^ for natural gas and
propane.
S = Specific gravity of gas at 60°F and 30-inch mercury col-
umn (0.60 for natural gas, 1 .50 for propane), or = 1488|i
T = Absolute temperature, °F or = r + 460
t = Temperature, °F
Z = Viscosity of gas, centipoise (0.012 for natural gas, 0.008
for propane), or = 1488|i
fba= Base friction factor for air at 60°F (CF=1)
L = Length of pipe, ft
AH= Pressure drop, in. w.c. (27.7 in. H2O = 1 psi)
(For SI, see Section 402.4)
C-A.5 Pipe and tube diameters. Where the internal diameter
is determined by the formulas in Section C402.4, Tables
C-A.5. 1 and C-A. 5. 2 can be used to select the nominal or stan-
dard pipe size based on the calculated internal diameter.
TABLE C-A.5.1
SCHEDULE 40 STEEL PIPE STANDARD SIZES
NOMINAL SIZE
(In.)
INTERNAL
DIAMETER
(In.)
NOMINAL
SIZE
(in.)
INTERNAL
DIAMETER
(in.)
'/4
0.364
1%
1.610
\
0.493
2
2.067
%
0.622
2V,
2.469
'U
0.824
3
3.068
1
1.049
3V,
3.548
I'A
1.380
4
4.026
TABLE C-A.5.2
COPPER TUBE STANDARD
SIZES
TUBE TYPE
NOMINAL OR
STANDARD SIZE
inches
INTERNAL DIAMETER
inches
K
\
0.305
L
V4
0.315
ACR (D)
\
0.315
ACR (A)
%
0.311
K
\
0.402
L
V,
0.430
ACR (D)
%
0.430
ACR (A)
%
0.436
K
'I2
0.527
L
%
0.545
ACR(D)
%
0.545
ACR (A)
%
0.555
K
\
0.652
L
%
0.666
ACR (D)
'U
0.666
ACR (A)
'U
0.680
K
%
0.745
L
'U
0.785
ACR
y.
0.785
K
1
0.995
L
1
1.025
ACR
i'/«
1.025
K
IV.
1.245
L
IV.
1.265
ACR
l\
1.265
K
IV,
1.481
L
IV,
1.505
ACR
l\
1.505
K
2
1.959
L
2
1.985
ACR
2V,
1.985
K
2V,
2.435
L
2V,
2.465
ACR
2V«
2.465
K
3
2.907
L
3
2.945
ACR
3V«
2.945
117.122
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C-A
C-A.6 Use of sizing charts. A third method of sizing gas pip-
ing is detailed below as an option that is useful when large
quantities of piping are involved in a job (e.g., an apartment
house) and material costs are of concern. If the user is not com-
pletely familiar with this method, the resulting pipe sizing
should be checked by a knowledgeable gas engineer. The siz-
ing charts are applied as follows.
(1) With the layout developed according to Section
C106.3.1 of the code, indicate in each section the de-
sign gas flow under maximum operation conditions.
For many layouts, the maximurri design flow will be the
sum of all connected loads. However, in some cases,
certain combinations of utilization equipment will not
occur simultaneously (e.g., gas heating and air condi-
tioning). For these cases, the design flow is the greatest
gas flow that can occur at any one time.
(2) Determine the inlet gas pressure for the system being
designed. In most cases, the point of inlet will be the gas
meter or service regulator, but in the case of a system
addition, it could be the point of connection to the exist-
ing system.
(3) Determine the minimum pressure required at the inlet
to the critical utilization equipment. Usually, the
critical item will be the piece of equipment with the
highest required pressure for satisfactory operation. If
several items have the same required pressure, it will be
the one with the greatest length of piping from the sys-
tem inlet.
(4) The difference between the inlet pressure and critical
item pressure is the allowable system pressure drop.
Figures C-A. 6(a) and C-A. 6(b) show the relationship
between gas flow, pipe size and pipe length for natural
gas with 0.60 specific gravity.
(5) To use Figure C-A.6(a) (low pressure applications),
calculate the piping length from the inlet to the critical
utiHzation equipment. Increase this length by 50 per-
cent to allow for fittings. Divide the allowable pressure
drop by the equivalent length (in hundreds of feet) to
determine the allowable pressure drop per hundred
feet. Select the pipe size from Figure C-A.6(a) for the
required volume of flow.
(6) To use Figure C-A.6(b) (high pressure applications),
calculate the equivalent length as above. Calculate the
index number for Figure C-A.6(b) by dividing the dif-
ference between the squares of the absolute values of
inlet and outlet pressures by the equivalent length (in
hundreds of feet). Select the pipe size from Figure
C-A.6(b) for the gas volume required.
2
^ 0.10
© 0.09
"• 0.07
0.06
0.05
0.04
VA
Vh
2V2
■""
~~
r
T
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7-
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r
7"
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f
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y
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r ■
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06
80
100 2C
4C
)0
6C
80
Liooo 20
00
4b
00
6C
00 1
0,000
FIGURE C-A.6 (a)
CAPACITY OF NATURAL GAS PIPING, LOW PRESSURE (0.60 WC)
2007 OREGON MECHANICAL SPECIALTY CODE
117.123
APPENDIX C-A
Index number =
Dist.
(100)
Dist. = Eq. length, ft
Pj = Initial press, abs. psi
P2 = Final press, abs. psi
%"
1" IV
4" 11/2"
T
2%" 3"
4"
5"
6"
8"
10" 12"
~2 ~
/
/
T"
/ /
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r^"'"
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r- --
9
V
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tL
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f
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10,000
1,000.000
10,000,000
FIGURE C-A.6 (b)
CAPACITY OF NATURAL GAS PIPING, HIGH PRESSURE (1.5 psi and above)
C-A.7 Examples of piping system design and sizing
C-A.7,1 Example \\ Longest length method. Determine the
required pipe size of each section and outlet of the piping sys-
tem shown in Figure C-A.7. 1, with a designated pressure drop
of 0.5-inch w.c. (125 Pa) using the Longest Length Method.
The gas to be used has 0.60 specific gravity and a heating value
of 1,000 Btu/ft^ (37.5 MJ/m3).
Solution:
(1) Maximum gas demand for Outlet A:
Consumption (rating plate input, or Table 402.2 if necessary)
Btu of gas
35,000 Btu per hour rating
= 35 cubic feet per hour = 35cfh
1,000 Btu per cubic foot
Maximum gas demand for Outlet B:
Maximum gas demand for Outlet D:
Consumption 100,000
Btu of gas
1,000
= 100 cfh
= 75 cfh
Consumption _ 75,000
Btu of gas ~ 1,000
Maximum gas demand for Outlet C:
Consumption 35,000
Btu of gas
1,000
35 cfh
(2) The length of pipe from the point of delivery to the
most remote outlet (A) is 60 feet (18 288 mm). This
is the only distance used.
(3) Using the row marked 60 feet (18 288 mm) in Table
402.4(2):
(a) Outlet A, supplying 35 cfh (0.99 m^/hr), re-
quires Vg-inch pipe.
(b) Outiet B, supplying 75 cfh (2.12 m^/hr), re-
quires V4-inch pipe.
(c) Section 1, supplying Outlets A and B, or 1 10
cfh (3.11 m^/hr), requires V4-inch pipe.
(d) Section 2, supplying Outlets C and D, or 135
cfh (3.82 m^/hr), requires V4-inch pipe.
(e) Section 3 , supplying Outlets A, B , C and D, or
245 cfh (6.94 m^/hr), requires 1-inch pipe.
(4) If a different gravity factor is applied to this exam-
ple, the values in the row marked 60 feet (18 288
mm) of Table C402.4(2) would be multiplied by the
appropriate multiplier from Table C-A. 2. 4 and the
resulting cubic feet per hour values would be used to
size the piping.
117.124
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C-A
Outlet C ♦—
40 gal. automatic
water heater
^000 Btu/h
Sections
20 «
10fl
Outlet D
furnace
1001000 Btu^
\ Section 2
/'20 ft
15ft
i Point of
delivery
}
M5ft
5 ft
Outlet A
clothes dryer
35P00Btu/h
Outlet B A"^
range/oven unit
751030 Btu/h
FIGURE C-A.7.1
PIPING PLAN SHOWING A STEEL PIPING SYSTEM
CA.7.2 Example 2: Hybrid or dual pressure systems. Deter-
mine the required CSST size of each section of the piping sys-
tem shown in Figure C-A.7.2, with a designated pressure drop
of 1 psi (6.9 kPa) for the 2 psi (13.8 kPa) section and 3-inch w.c.
(0.75 kPa) pressure drop for the 13-inch w.c. (2.49 kPa) sec-
tion. The gas to be used has 0.60 specific gravity and a heating
value of 1,000 Btu/ft^ (37.5 MJ/ m^).
Solution
(1) Size 2 psi (13.8 kPa) line using Table C402.4(17).
(2) Size 10-inch w.c. (2.5 kPa) lines using Table
C402.4(15).
(3) Using the following, determine if sizing tables can be
used.
(a) Total gas load shown in Figure C-A.7.2 equals
110 cfh (3.11 m^/hr).
(b) Determine pressure drop across regulator [see
notes in Table C402.4 (17)].
(c) If pressure drop across regulator exceeds V4 psig
(5.2 kPa), Table C402.4 (17) cannot be used.
Note: If pressure drop exceeds V4 psi (5.2 kPa),
then a larger regulator must be selected or an al-
ternative sizing method must be used.
(d) Pressure drop across the line regulator [for 1 10
cfh (3.11 m^/hr)] is 4-inch w.c. (0.99 kPa) based
on manufacturer's performance data.
(e) Assume the CSST manufacturer has tubing sizes
or EHDs of 13, 18, 23 and 30.
(4) Section A [2 psi (13.8 kPa) zone]
(a) Distance from meter to regulator = 100 feet (30
480 mm).
(b) Total load supplied by A = 1 10 cfh (3.1 1 m^/hr)
(furnace 4- water heater + dryer).
(c) Table C402.4 (17) shows that EHD size 18
should be used.
Note: It is not unusual to oversize the supply line
by 25 to 50 percent of the as-installed load. EHD
size 18 has a capacity of 189 cfh (5.35 m^/hr).
(5) Section B (low pressure zone)
(a) Distance from regulator to furnace is 15 feet (4572
mm).
(b) Load is 60 cfh (1.70 m3/hr).
(c) Table C402.4 (15) shows that EHD size 13
should be used.
(6) Section C (low pressure zone)
(a) Distance from regulator to water heater is 10
feet (3048 mm).
(b) Load is 30 cfh (0.85 m^/hr).
(c) Table C402.4 (15) shows that EHD size 13
should be used.
(7) Section D (low pressure zone)
(a) Distance from regulator to dryer is 25 feet (7620
mm).
(b) Load is 20 cfh (0.57 m^/hr).
(c) Table C402.4(15) shows that EHD size 13 should
be used.
Length of luns:
Key:
A=lOOft
B=15{«
CslOft
Wi Manifold
X Shut-off valva
Oct 25 ft
^ Pressure regulator
(m) Gas meter
FIGURE C-A.7.2
PIPING PLAN SHOWING A CSST SYSTEM
C-A.7.3 Example 3: Branch length method. Determine the
required semi-rigid copper tubing size of each section of the
piping system shown in Figure C-A.7.3, with a designated
pressure drop of 1-inch w.c. (250 Pa) (using the Branch Length
Method). The gas to be used has 0.60 specific gravity and a
heating value of 1,000 Btu/ft^ (37.5 MJ/m^).
Solution
(1) Section A
(a) The length of tubing from the point of delivery to
the most remote appliance is 50 feet (15 240
mm), A + C.
2007 OREGON MECHANICAL SPECIALTY CODE
117.125
APPENDIX C-A
(b) Use this longest length to size Sections A and C.
(c) Using the row marked 50 feet (15 240 mm) in Ta-
ble 402.4(9), Section A, supplying 220 cfh (6.2
m^/hr) for four appliances requires 1-inch tubing.
(2) Sections
(a) The length of tubing from the point of delivery to
the range/oven at the end of Section B is 30 feet
(9144 mm), A -hB.
(b) Use this branch length to size Section B only.
(c) Using the row marked 30 feet (9144 mm) in Ta-
ble 402.4(9), Section B, supplying 75 cfh (2.12
m-'/hr) for the range/oven requires '^-inch tub-
(3)
(4)
mg.
Section C
(a) The length of tubing from the point of delivery to
the dryer at the end of Section C is 50 feet (15 240
mm), A -I- C.
(b) Use this branch length (which is also the longest
length) to size Section C.
(c) Using the row marked 50 feet ( 1 5 240 mm) in Ta-
ble 402.4(9), Section C, supplying 30 cfh (0.85
m^/hr) for the dryer requires ^/g-inch tubing.
Section D
(a)
(b)
(c)
The length of tubing from the point of delivery to
the water heater at the end of Section D is 30 feet
(9144 mm), A -h D.
Use this branch length to size Section D only.
Using the row marked 30 feet (9144 mm) in Ta-
ble 402.4(9), Section D, supplying 35 cfh (0.99
m^/hr) for the water heater requires Vg-inch tub-
ing.
00
DO
Range/oven
75 cfh
Section A
J
Section B f
Section C
M
J~^ Section D
r
r
h
^
220 cfh
IP
Section
E ^
^,-s. Wate
■^ Jheate
^-^35cf
F
urnac
BOcfl-
e
1
u
Dryer
30 cfh
Length of runs:
Key:
A = 20 ft
B = 10ft
C = 30ft
iHl Manifold
X Shut-off valve
D=10ft
j M 1 Gas meter
E = 10f1
Total gas load = 220 cfh
(5) Section E
(a) The length of tubing from the point of delivery to
the furnace at the end of Section E is 30 feet
(9144 mm), A + E.
(b) Use this branch length to size Section E only.
(c) Using the row marked 30 feet (9144 mm) in Ta-
ble 402.4(9), Section E, supplying 80 cfh (2.26
m^/hr) for the furnace requires V2-inch tubing.
C-A.7.4 Example 4: Modification to existing piping system.
Determine the required CSST size for Section G (retrofit appli-
cation) of the piping system shown in Figure C-A.7.4, with a
designated pressure drop of 0.5-inch w.c. (125 Pa) using the
branch length method. The gas to be used has 0.60 specific
gravity and a heating value of 1,000 Btu/ft^ (37.5 MJ/m^).
Solution
(1) The length of pipe and CSST from the point of delivery
to the retrofit appliance (barbecue) at the end of Section
G is 40 feet (12 192 mm), A -<- B -h G.
(2) Use this branch length to size Section G.
(3) Assume the CSST manufacturer has tubing sizes or
EHDsof 13, 18, 23 and 30.
(4) Using the row marked 40 feet (12 192 mm) in Table
C402.4(14), Section G, supplying 40 cfh (1.13 m^/hr)
for the barbecue requires EHD 18 CSST.
(5) The sizing of Sections A, B, F and E must be checked to
ensure adequate gas carrying capacity since an appli-
ance has been added to the piping system (see C-A. 7. 1
for details).
Section A
Section 8
Section G
Section C
T
Section F
Section E
Furnace
80 cfh
Section D
Range/oven
75 cfh
Length of runs:
A=15ft E=:5ft
B = 10ft F=10ft
C = 15ft G = 15ft
D = 20ft
Key:
X Shut-off valve
[m] Gas meter
FIGURE C-A.7.3
PIPING PLAN SHOWING A COPPER TUBING SYSTEM
FIGURE C-A.7.4
PIPING PLAN SHOWING A MODIFICATION
TO EXISTING PIPING SYSTEM
117.126
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C-B
SIZING OF VENTING SYSTEMS SERVING APPLIANCES EQUIPPED
WITH DRAFT HOODS, CATEGORY I APPLIANCES, AND
APPLIANCES LISTED FOR USE WITH TYPE B VENTS
(This appendix is informative and is not part of the code.)
EXAMPLES USING SINGLE
APPLIANCE VENTING TABLES
Example 1: Single draft-hood-equipped appliance
An installer has a 120,000 British thermal unit (Btu) per hour
input appliance with a 5 -inch-diameter draft hood outlet that
needs to be vented into a 10-footfhigh Type B vent system.
What size vent should be used assuming (a) a 5 -foot lateral sin-
gle-wall metal vent connector is used with two 90-degree el-
bows, or (b) a 5-foot lateral single- wall metal vent connector is
used with three 90-degree elbows in the vent system?
Table C504.2(2) should be used to solve this problem, because sin-
gle-wall metal vent connectors are being used with a Type B vent.
(a) Read down the first column in Table C504.2(2) until the
row associated with a 10-foot height and 5-foot lateral
is found. Read across this row until a vent capacity
greater than 120,000 Btu per hour is located in the
shaded columns labeled "NAT Max" for draft-hood-
TYPE B DOUBLE-WALL—
GAS VENT
-I )
'J
For SI: 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W
Table C504.2( 1 ) is used when sizing Jype B double-wall gas vent con-
nected directly to the appliance.
Note: The appliance may be either Category I draft hood equipped or fan-
assisted type.
FIGURE C-B-1
TYPE B DOUBLE-WALL VENT SYSTEM SERVING A SINGLE
APPLIANCE WITH A TYPE B DOUBLE-WALL VENT
(b)
equipped appliances. In this case, a 5 -inch-diameter
vent has a capacity of 122,000 Btu per hour and may be
used for this application.
If three 90-degree elbows are used in the vent system,
then the maximum vent capacity listed in the tables
must be reduced by 10 percent (see Section C504.2.3
for single appliance vents). This implies that the 5-
inch-diameter vent has an adjusted capacity of only
1 10,000 Btu per hour. In this case, the vent system must
be increased to 6 inches in diameter (see calculations
below).
122,000 (.90) = 11 0,000 for 5-inch vent
From Table C504.2(2), Select 6-inch vent
186,000 (.90) = 167,000; This is greater than the re-
quired 120,000. Therefore, use a 6-inch vent and con-
nector where three elbows are used.
TYPE B DOUBLE-WALL—
GAS VENT
SINGLE-WALL VENT-
CONNECTOR
For SI: 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.293 1VS(
Table C504.2(2) is used when sizing a single- wall metal vent connector
attached to a Type B double-wall gas vent.
Note: The appliance may be either Category I draft hood equipped or fan-
assisted type.
FIGURE C-B-2
TYPE B DOUBLE-WALL VENT SYSTEM SERVING
A SINGLE APPLIANCE WITH A SINGLE-WALL
METAL VENT CONNECTOR
2007 OREGON MECHANICAL SPECIALTY CODE
117.127
APPENDIX C-B
TILE-LINED MASONRY-
CHIMNEY
I H — VENT CAP
^
TYPE B DOUBLE-WALL-
GAS VENT USED AS
CONNECTOR
Table C504.2(3) is used when sizing a Type B double- wall gas vent connec-
tor attached to a tile-lined masonry chimney.
Note: "A" is the equivalent cross-sectional area of the tile liner.
Note: The appliance may be either Category I draft hood equipped or fan-
assisted type.
FIGURE C-B-3
VENT SYSTEM SERVING A SINGLE APPLIANCE
WITH A MASONRY CHIMNEY OF TYPE B
DOUBLE-WALL VENT CONNECTOR
Asbestos cement Type B or single-wall metal vent serving a single draft-
hood-equipped appliance [see Table C504.2(5)].
FIGURE C-B-5
ASBESTOS CEMENT TYPE B OR SINGLE-WALL
METAL VENT SYSTEM SERVING A SINGLE
DRAFT-HOOD-EQUIPPED APPLIANCE
h°-VENT CAP
TILE-LINED MASONRY-
CHIMNEY
SINGLE-WALL VENT-H
CONNECTOR
Table C504.2(4) is used when sizing a single-wall vent connector attached
to a tile-lined masonry chimney.
Note: "A" is the equivalent cross-sectional area of the tile liner.
Note: The appliance may be either Category I draft hood equipped or fan-
assisted type.
FIGURE C-B-4
VENT SYSTEM SERVING A SINGLE APPLIANCE
USING A MASONRY CHIMNEY AND A
SINGLE-WALL METAL VENT CONNECTOR
Table C504.3(l) is used when sizing Type B double- wall vent connectors
attached to a Type B double-wall common vent.
Note: Each appliance may be either Category I draft hood equipped or fan-
assisted type.
FIGURE C-B-6
VENT SYSTEM SERVING TWO OR MORE APPLIANCES
WITH TYPE B DOUBLE-WALL VENT AND TYPE B
DOUBLE-WALL VENT CONNECTOR
117.128
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C-B
h VENT CAP
TILE-LINED MASONRY
CHIMNEY
Table C504.3(2) is used when sizing single-wall vent connectors attached
to a Type B double-wall common vent.
Note: Each appliance may be either Category I draft hood equipped or fan-
assisted type.
FIGURE C-B-7
VENT SYSTEM SERVING TWO OR MORE APPLIANCES
WITH TYPE B DOUBLE-WALL VENT AND
SINGLE-WALL METAL VENT CONNECTORS
Table C504.3(4) is used when sizing single-wall metal vent connectors at-
tached to a tile-lined masonry chimney.
Note: "A" is the equivalent cross-sectional area of the tile liner.
Note: Each appliance may be either Category I draft hood equipped or fan-
assisted type.
FIGURE C-B-9
MASONRY CHIMNEY SERVING TWO OR MORE APPLIANCES
WITH SINGLE-WALL METAL VENT CONNECTORS
TYPE B DOUBLE-WALL
H GAS VENT USED AS
CONNECTORS
/T
-TILE-LINED MASONRY
CHIMNEY
e_B
5^
CONNECTOR
RISE -R"
Table C504.3(3) is used when sizing Type B double-wall vent connectors
attached to a tile-lined masonry chimney.
Note: "A" is the equivalent cross-sectional area of the tile liner.
Note: Each appliance may be either Category I draft hood equipped or fan-
assisted type.
FIGURE C-B-8
MASONRY CHIMNEY SERVING TWO OR MORE APPLIANCES
WITH TYPE B DOUBLE-WALL VENT CONNECTOR
Asbestos cement Type B or single- wall metal pipe vent serving two or more
draft-hood-equipped appliances [see Table C504.3(5)].
FIGURE C-B-10
ASBESTOS CEMENT TYPE B OR SINGLE-WALL
METAL VENT SYSTEM SERVING TWO OR MORE
DRAFT-HOOD-EQUIPPED APPLIANCES
2007 OREGON MECHANICAL SPECIALTY CODE
117.129
APPENDIX C-B
VENT CONNECTOR
•COMMON VENT SIZE BASED—
ON ALL INPLTTS ENTERING THIS
SEGMENT, AND AVAILABLE
TOTAL HEIGHT
■AVAILABLE TOTAL HEIGHT
■H- EQUALS RISE PLUS
DISTANCE BETWEEN TEES
Example: Manifolded Common Vent Connector L„ shall be no greater than
18 times the common vent connector manifold inside diameter; i.e., a 4-
inch (102 mm) inside diameter common vent connector manifold shall not
exceed 72 inches (1829 mm) in length (see Section C504.3.4).
Note: This is an illustration of a typical manifolded vent connector. Differ-
ent appliance, vent connector, or common vent types are possible. Consult
Section C502.3.
FIGURE C-B-11
USE OF MANIFOLD COMMON VENT CONNECTOR
V//////////////A
Vent connector size depends on:
° Input
°Rise
o Av£iilable total height "H"
o Table C504.3(l) connectors
Common vent size depends on :
° Combined inputs
° Available total height "//"
" Table C504.3(l) common vent
FIGURE C-B-1 3
MULTISTORY GAS VENT DESIGN PROCEDURE
FOR EACH SEGMENT OF SYSTEM
USE INDIVIDUAL
VENT FOR TOP FLOOR
APPLIANCE IF
CONNECTOR
REQUIREMENT FOR
RISE OF TOTAL HEIQHT
CANNOT BE MET
AVAILABLE TOTAL
HEIGHT FOR TOP
FLOOR APPLIANCE
&
AVAILABLE TOTAL
HEIGHT FOR
THIRD-FLOOR
APPUANCE
s.
USE AVAIUBLE TOTAL HEIGHT FOR
TOP FLOOR APPLIANCE AND
COMBINE INPUT OF ALL APPLIANCES
ON COMMON VENT
%-
THIRD INTERCONNECTION TEE"
- AVAILABLE TOTAL HEIQHT FOR
THIHO-FLOOH APPLIANCE AND
COMBINED INPUT OF THREE
APPLIANCES (IF TOP FLOOR
APPLIANCE IS NOT CONNECTED,
MEASURED TOTAL HEIGHT TO
VENT TOP)
%-
AVAILABLE TOTAL
HEIQHT FOR
SECOND-FLOOR
APPLIANCE
s.
SECOND INTERCONNECTION TEE"
-USE AVAILABLE TOTAL HEIGHT FOR
SECOND-FLOOR APPLIANCE AND
COMBINED HEAT INPUT OF TWO
APPLIANCES
-FIRST INTERCONNECTION TEE-
DESIGN VENT CONNECTOR FOR FIRST
FLOOR APPLIANCE AS AN IN DIVIDUAL
VENTOFTHISTOTALHEIQHT FOR INPLT
OF FIRST FLOOR APPLIANCE
Example: Offset Common Vent
Note: This is an illustration of a typical offset vent. Different appliance,
vent connector, or vent types are possible. Consult Sections C504.2 and
C504.3.
FIGURE C-B-1 2
USE OF OFFSET COMMON VENT
S.
-TEE WITTI CAP OPTIONAL
Principles of design of multistory vents using vent connector and common
vent design tables (see Sections C504.3.11 through C504.3.17).
FIGURE C-B-1 4
MULTISTORY VENT SYSTEMS
117.130
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C-B
^^
- i ryi r
TYPE B DOUBLE-WALL-
GAS VENT
>-;
Zl
•5ft-
Y
^
SINGLE WALL
CONNECTOR
10ft
DRAFT HOOD EQUIPPED APPLIANCE
120,000 BTU/H INPUT
For SI: 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.293 1 W
FIGURE C-B-1 5 (EXAMPLE 1 )
SINGLE DRAIH'-HOOD-EQUIPPED APPLIANCE
¥1
TYPE-B DOUBLE-WALL-
GAS VENT
10 FT LATERAL-
T
^
VENT CONNECTOR
FAN ASSISTED APPLIANCE
80,000 BTU/H INPUT
For SI: 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.293 1 W
FIGURE C-B-16 (EXAMPLE 2)
SINGLE FAN-ASSISTED APPLIANCE
Example 2% Single fan-assisted appliance
An installer has an 80,000 Btu per hour input fan-assisted ap-
pliance that must be installed using 10 feet of lateral connector
attached to a 30-foot-high Type B vent. Two 90-degree elbows
are needed for the installation. Can a single-wall metal vent
connector be used for this application?
Solution:
Table C504.2(2) refers to the use of single- wall metal vent con-
nectors with Type B vent. In the first column find the row asso-
ciated with a 30-foot height and a 10-foot lateral. Read across
this row, looking at the FAN Min and FAN Max columns, to
find that a 3-inch-diameter single-wall metal vent connector is
not recommended. Moving to the next larger size single wall
connector (4 inches), note that a 4-inch-diameter single-wall
metal connector has a recommended minimum vent capacity of
91,000 Btu per hour and a recommended maximum vent ca-
pacity of 144,000 Btu per hour. The 80,000 Btu per hour fan-
assisted appliance is outside this range, so the conclusion is that
a single-wall metal vent connector cannot be used to vent this
apphance using 10 feet of lateral for the connector.
However, if the 80,000 Btu per hour input appliance could be
moved to within 5 feet of the vertical vent, then a 4-inch single-
wall metal connector could be used to vent the appliance. Table
504.2(2) shows the acceptable range of vent capacities for a 4-
inch vent with 5 feet of lateral to be between 72,000 Btu per
hour and 157,000 Btu per hour.
If the appliance cannot be moved closer to the vertical vent,
then Type B vent could be used as the connector material. In
this case. Table C504.2(l) shows that for a 30-foot-high vent
with 10 feet of lateral, the acceptable range of vent capacities
for a 4-inch-diameter vent attached to a fan-assisted appliance
is between 37,000 Btu per hour and 150,000 Btu per hour.
Example 3: Interpolating between table values
An installer has an 80,000 Btu per hour input appliance with a
4-inch-diameter draft hood outlet that needs to be vented into a
12-foot-high Type B vent. The vent connector has a 5-foot lat-
eral length and is also Type B. Can this appliance be vented us-
ing a 4-inch-diameter vent?
Solution:
Table C504.2(l) is used in the case of an all Type B vent sys-
tem. However, since there is no entry in Table 504.2(1) for a
height of 12 feet, interpolation must be used. Read down the 4-
inch diameter NAT Max column to the row associated with 10-
foot height and 5 -foot lateral to find the capacity value of
77,000 Btu per hour. Read further down to the 15-foot height,
5-foot lateral row to find the capacity value of 87,000 Btu per
hour. The difference between the 15 -foot height capacity value
and the 10-foot height capacity value is 10,000 Btu per hour.
The capacity for a vent system with a 12-foot height is equal to
the capacity for a 10-foot height plus V5 of the difi'erence be-
tween the 10-foot and 15-foot height values, or 77,000 + ^/g
(10,000) = 81,000 Btu per hour. Therefore, a 4-inch-diameter
vent may be used in the installation.
EXAMPLES USING COMMON VENTING TABLES
Example 4: Common venting two draft-hood-equipped ap-
pliances
A 35,000 Btu per hour water heater is to be common vented
with a 150,000 Btu per hour furnace using a common vent with
a total height of 30 feet. The connector rise is 2 feet for the wa-
ter heater with a horizontal length of 4 feet. The connector rise
for the furnace is 3 feet with a horizontal length of 8 feet. As-
sume single-wall metal connectors will be used with Type B
vent. What size connectors and combined vent should be used
in this installation?
2007 OREGON MECHANICAL SPECIALTY CODE
117.131
APPENDIX C-B
COMBINED CAPACITY
35.000 + 1 50,000 = 1 85,000 BTU/H
-TYPE B DOUBLE-WALL
GAS VENT
DRAFT HOOD-EQUIPPED
WATER HEATER
35,000 BTU/H INPUT
DRAFT HOOD-EQUiPMEhfT
FURNACE
150,000 BTU/H INPUT
FIGURE C-B-17 (EXAMPLE 4)
COMMON VENTING TWO DRAFT-
HOOD-EQUIPPED APPLIANCES
Solution:
Table C504.3(2) should be used to size single-wall metal vent
connectors attached to Type B vertical vents. In the vent con-
nector capacity portion of Table C504.3(2), find the row asso-
ciated with a 30-foot vent height. For a 2-foot rise on the vent
connector for the water heater, read the shaded columns for
draft-hood-equipped appliances to find that a 3 -inch-diameter
vent connector has a capacity of 37,000 Btu per hour. There-
fore, a 3 -inch single- wall metal vent connector may be used
with the water heater. For a draft-hood-equipped furnace with a
3-foot rise, read across the appropriate row to find that a 5-inch-
diameter vent connector has a maximum capacity of 120,000
Btu per hour (which is too small for the furnace) and a 6-inch-
diameter vent connector has a maximum vent capacity of
172,000 Btu per hour. Therefore, a 6-inch-diameter vent con-
nector should be used with the 150,000 Btu per hour furnace.
Since both vent connector horizontal lengths are less than the
maximum lengths listed in Section C504.3.2, the table values
may be used without adjustments.
In the common vent capacity portion of Table C504.3(2),
find the row associated with a 30-foot vent height and read over
to the NAT + NAT portion of the 6-inch-diameter column to
find a maximum combined capacity of 257,000 Btu per hour.
Since the two appliances total only 185,000 Btu per hour, a 6-
inch common vent may be used.
Example 5a: Common venting a draft-hood-equipped wa-
ter heater with a fan-assisted furnace into a Type B vent
In this case, a 35,000 Btu per hour input draft-hood-
equipped water heater with a 4-inch-diameter draft hood out-
let, 2 feet of connector rise, and 4 feet of horizontal length is to
be common vented with a 100,000 Btu per hour fan-assisted
furnace with a 4-inch-diameter flue collar, 3 feet of connector
rise, and 6 feet of horizontal length. The common vent consists
of a 30-foot height of Type B vent. What are the recommended
vent diameters for each connector and the common vent? The
installer would like to use a single-wall metal vent connector.
Solution: - [Table C504.3(2)]
Water Heater Vent Connector Diameter. Since the water heater
vent connector horizontal length of 4 feet is less than the maxi-
mum value listed in Section C504.3.2, the venting table values
may be used without adjustments. Using the Vent Connector
Capacity portion of Table C504.3(2), read down the Total Vent
Height (H) column to 30 feet and read across the 2-foot Con-
nector Rise (R) row to the first Btu per hour rating in the NAT
Max column that is equal to or greater than the water heater in-
put rating. The table shows that a 3-inch vent connector has a
maximum input rating of 37,000 Btu per hour. Although this is
greater than the water heater input rating, a 3 -inch vent connec-
tor is prohibited by Section C504.3.21. A 4-inch vent connec-
tor has a maximum input rating of 67,000 Btu per hour and is
equal to the draft hood outlet diameter. A 4-inch vent connector
is selected. Since the water heater is equipped with a draft hood,
there are no minimum input rating restrictions.
Furnace Vent Connector Diameter. Using the Vent Connec-
tor Capacity portion of Table C504.3(2), read down the TotJil
Vent Height (H) colunm to 30 feet and across the 3-foot Con-
nector Rise (R) row. Since the furnace has a fan-assisted com-
bustion system, find the first FAN Max column with a Btu per
hour rating greater than the furnace input rating. The 4-inch
vent connector has a maximum input rating of 1 19,000 Btu per
hour and a minimum input rating of 85,000 Btu per hour. The
100,000 Btu per hour furnace in this example falls within this
range, so a 4-inch connector is adequate. Since the furnace vent
connector horizontal length of 6 feet does not exceed the maxi-
mum value listed in Section C504.3.2, the venting table values
may be used without adjustment. If the furnace had an input rat-
ing of 80,000 Btu per hour, then a Type B vent connector [see
Table C504.3(l)] would be needed in order to meet the mini-
mum capacity limit.
Common Vent Diameter. The total input to the common vent
is 135,000 Btu per hour. Using the Common Vent Capacity por-
tion of Table C504.3(2), read down the Total Vent Height (f/)
column to 30 feet and across this row to find the smallest vent
diameter in the FAN -i- NAT column that has a Btu per hour rat-
ing equal to or greater than 135,000 Btu per hour. The 4-inch
common vent has a capacity of 132,000 Btu per hour and the 5-
inch common vent has a capacity of 202,000 Btu per hour.
Therefore, the 5 -inch common vent should be used in this ex-
ample.
Summary. In this example, the installer may use a 4-inch-di-
ameter, single- wall metal vent connector for the water heater
and a 4-inch-diameter, single-wall metal vent connector for the
furnace. The common vent should be a 5-inch-diameter Type B
vent.
Example 5b: Common venting into a masonry chimney
In this case, the water heater and fan-assisted furnace of Exam-
ple 5 a are to be common vented into a clay tile-lined masonry
chimney with a 30-foot height. The chimney is not exposed to
the outdoors below the roof line. The internal dimensions of the
117.132
2007 OREGON MECHANICAL SPECIALTY CODE
APPENDIX C-B
FIGURE C-B-18 (EXAMPLE 5A)
COMMON VENTING A DRAFT HOdD WITH A FAN-ASSISTED
FURNACE INTO A TYPE B DOUBLE-WALL COMMON VENT
clay tile liner are nominally 8 inches by 12 inches. Assuming
the same vent connector heights, laterals, and materials found
in Example 5a, what are the recommended vent connector di-
ameters, and is this an acceptable installation?
Solution:
Table C504.3(4) is used to size common venting installations
involving single-wall connectors into masonry chimneys.
Water Heater Vent Connector Diameter. Using Table
C504.3(4), Vent Connector Capacity, read down the Total Vent
Height (H) column to 30 feet, and read across the 2-foot Con-
nector Rise (R) row to the first Btu per hour rating in the NAT
Max column that is equal to or greater than the water heater in-
put rating. The table shows that a 3-inch vent connector has a
maximum input of only 31,000 Btu per hour while a 4-inch
vent connector has a maximum input of 57,000 Btu per hour. A
4-inch vent connector must therefore be used.
Furnace Vent Connector Diameter. Using the Vent Connec-
tor Capacity portion of Table C504.3(4), read down the Total
Vent Height (H) column to 30 feet and across the 3-foot Con-
nector Rise (R) row. Since the ftimace has a fan-assisted com-
bustion system, find the first FAN Max column with a Btu per
hour rating greater than the furnace input rating. The 4-inch
vent connector has a maximum input rating of 127,000 Btu per
hour and a minimum input rating of 95,000 Btu per hour. The
100,000 Btu per hour furnace in this example falls within this
range, so a 4-inch connector is adequate.
Masonry Chimney. From Table C-B- 1, the equivalent area
for a nominal liner size of 8 inches by 12 inches is 63.6 square
inches. Using Table C504.3(4), Common Vent Capacity, read
down the FAN + NAT column under the Minimum Internal
Area of Chimney value of 63 to the row for 30-foot height to
find a capacity value of 739,000 Btu per hour. The combined
input rating of the furnace and water heater, 135,000 Btu per
hour, is less than the table value, so this is an acceptable instal-
lation.
Section C504.3.17 requires the common vent area to be no
greater than seven times the smallest listed appliance catego-
rized vent area, flue collar area, or draft hood outlet area. Both
appliances in this installation have 4-inch-diameter outlets.
From Table C-B- 1 , the equivalent area for an inside diameter of
4 inches is 12.2 square inches. Seven times 12.2 equals 85.4,
which is greater than 63 .6, so this configuration is acceptable.
Example 5c: Common venting into an exterior masonry
chimney
In this case, the water heater and fan-assisted furnace of Exam-
ples 5a and 5b are to be common vented into an exterior ma-
sonry chimney. The chimney height, clay tile liner dimensions,
and vent connector heights and laterals are the same as in Ex-
ample 5b. This system is being installed in Charlotte, North
Carolina. Does this exterior masonry chimney need to be re-
lined? If so, what corrugated metallic liner size is recom-
mended? What vent connector diameters are recommended?
Solution:
According to Section C504.3.20, Type B vent connectors are
required to be used with exterior masonry chimneys. Use Table
C504.3(8) to size FAN+NAT common venting installations in-
volving Type-B double wall connectors into exterior masonry
chimneys.
The local 99-percent winter design temperature needed to
use Table C504.3(8) can be found in the ASHRAE Handbook
of Fundamentals. For Charlotte, North Carolina, this design
temperature is 19°F.
Chimney Liner Requirement. As in Example 5b, use the 63
square inch Internal Area columns for this size clay tile liner.
Read down the 63 square inch column of Table C504.3(8a) to
the 30-foot height row to find that the combined appliance
maximum input is 747,000 Btu per hour. The combined input
rating of the appliances in this installation, 135,000 Btu per
hour, is less than the maximum value, so this criterion is satis-
fied. Table C504.3(8b), at a 19°F design temperature, and at the
same vent height and internal area used above, shows that the
minimum allowable input rating of a space-heating appliance
is 470,000 Btu per hour. The furnace input rating of 100,000
Btu per hour is less than this minimum value. So this criterion is
not satisfied, and an alternative venting design needs to be
used, such as a Type B vent shown in Example 5a or a listed
chimney liner system shown in the remainder of the example.
According to Section C504.3.19, Table C504.3(l) or
C504.3(2) is used for sizing corrugated metallic liners in ma-
sonry chimneys, with the maximum common vent capacities
reduced by 20 percent. This example will be continued assum-
ing Type B vent connectors.
Water Heater Vent Connector Diameter. Using Table
C504.3(l), Vent Connector Capacity, read down the Total Vent
2007 OREGON MECHANICAL SPECIALTY CODE
117.133
APPENDIX C-B
Height (H) column to 30 feet, and read across the 2-foot Con-
nector Rise (R) row to the first Btu/h rating in the NAT Max col-
umn that is equal to or greater than the water heater input rating.
The table shows that a 3-inch vent connector has a maximum
capacity of 39,000 Btu/h. Although this rating is greater than
the water heater input rating, a 3-inch vent connector is prohib-
ited by Section C504.3.21 . A 4-inch vent connector has a maxi-
mum input rating of 70,000 Btu/h and is equal to the draft hood
outlet diameter. A 4-inch vent connector is selected.
Furnace Vent Connector Diameter. Using Table C504.3(l),
Vent Connector Capacity, read down the Vent Height (H) col-
umn to 30 feet, and read across the 3 -foot Connector Rise (R)
row to the first Btu per hour rating in the FAN Max column that
is equal to or greater than the furnace input rating. The 100,000
Btu per hour furnace in this example falls within this range, so a
4-inch connector is adequate.
Chimney Liner Diameter. The total input to the common
vent is 135,000 Btu per hour. Using the Common Vent Capac-
ity Portion of Table C504.3(l), read down the Vent Height (//)
column to 30 feet and across this row to find the smallest vent
diameter in the FAN+NAT column that has a Btu per hour rat-
ing greater than 135,000 Btu per hour. The 4-inch common
vent has a capacity of 1 38,000 Btu per hour. Reducing the max-
imum capacity by 20 percent (Section C504.3.17) results in a
maximum capacity for a 4-inch corrugated liner of 110,000
Btu per hour, less than the total input of 135,000 Btu per hour.
So a larger liner is needed. The 5-inch common vent capacity
listed in Table C504.3(l) is 210,000 Btu per hour, and after re-
ducing by 20 percent is 168,000 Btu per hour. Therefore, a 5-
inch corrugated metal liner should be used in this example.
Single- Wall Connectors. Once it has been established that
relining the chimney is necessary, Type B double-wall vent
connectors are not specifically required. Jhis example could be
redone using Table C504.3(2) for single-wall vent connectors.
For this case, the vent connector and liner diameters would be
the same as found above with Type B double- wall connectors.
TABLE C-B-1
MASONRY CHIMNEY LINER DIMENSIONS
WITH CIRCULAR EQUIVALENTS^
NOMINAL
LINER SIZE
(inches)
INSIDE
DIMENSIONS
OF LINER
(inches)
INSIDE
DIAMETER OR
EQUIVALENT
DIAMETER
(inches)
EQUIVALENT
AREA
(square inches)
4x8
2% X 6V2
4
12.2
5
19.6
6
28.3
7
38.3
8x8
6V4 X 6%
7.4
42.7
8
50.3
8x12
6V2 X 10'/2
9
63.6
10
78.5
12x12
9% X 9V4
10.4
83.3
11
95
12x16
9V2 X 13'/2
11.8
107.5
12
113.0
14
153,9
16 X 16
I3V4 X I3V4
14.5
162.9
15
176.7
16x20
13x17
16.2
206.1
18
254.4
20x20
16% X 16%
18.2
260.2
20
314.1
20x24
I6V2 X 20'/2
20.1
314.2
22
380.1
24x24
20 V4 X 20 '/4
22.1
380.1
24
452.3
24x28
20V4 X 2OV4
24.1
456.2
28x28
24 V4 X 24 V4
26.4
543.3
27
572.5
30 X 30
25 V2 X 25 V2
27.9
607
30
706.8
30x36
25V2X31V2
30.9
749.9
33
855.3
36x36
3IV2X3172
34.4
929.4
36
1017.9
For SI: 1 inch = 25.4 mm, 1 square inch = 645. 1 6 m^.
a. Where liner sizes differ dimensionally from those shown in Table C-B-1,
equivalent diameters may be determined from published tables for
square and rectangular ducts of equivalent carrying capacity or by other'
engineering methods.
117.134
2007 OREGON MECHANICAL SPECIALTY CODE
-10T
(-23°C)
-10T
(.23°C)
37'F
(3°C)
37T
(3°C)
FIGURE C-B-1 9
>
■D
■0
m
z
o
X
o
d)
117.136
2007 OREGON MECHAMICAL SPECIALTY CODE
APPENDIX C-C (IFGS)
EXIT TERMINALS OF MECHANICAL DRAFT AND
DIRECT-VENT VENTING SYSTEMS
(This appendix is informative and is not part of the code.)
DIRECT-VENT TERMINAL CLEARANCE
MINIMUM CLEARANCE, C
INPUT (BTU/HR) CLEARANCE (IN.)
10.000 OR LESS 6
10.001 TO 50,000 9
OVER 50,000 12
[SEE SECTION 503.8, ITEM 3]
MECHANICAL DRAFT
VENT TERMINAL
[SEE SECTION 503.8, ITEM 1]
^FORCED-AIR INLET
•
For SI: 1 inch - 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W
APPENDIX C-C
EXIT TERMINALS OF MECHANICAL DRAFT AND DIRECT-VENT VENTING SYSTEMS
2007 OREGON MECHANICAL SPECIALTY CODE
117.137
w
117.138 2007 OREGON R/iECHANDCAL SPECIALTY CODIE
APPENDIX C-D
RECOMMENDED PROCEDURE FOR SAFETY INSPECTION OF AN
EXISTING APPLIANCE INSTALLATION
(This appendix is informative and is not part of the code.)
•
The following procedure is intended as a guide to aid in deter-
mining that an appliance is properly installed and is in a safe
condition for continuing use.
This procedure is predicated on central furnace and boiler in-
stallations, and it should be recognized that generalized proce-
dures cannot anticipate all situations. Accordingly, in some
cases, deviation from this procedure is necessary to determine
safe operation of the equipment.
(a) This procedure should be performed prior to any at-
tempt at modification of the appliance or of the installa-
tion.
(b) If it is determined there is a condition that could result
in unsafe operation, the appliance should be shut off
and the owner advised of the unsafe condition. The fol-
lowing steps should be followed in making the safety
inspection:
1. Conduct a test for gas leakage. (See Section
C406.6)
2. Visually inspect the venting system for proper
size and horizontal pitch and determine there is
no blockage or restriction, leakage, corrosion,
and other deficiencies that could cause an unsafe
condition.
3. Shut off all gas to the appliance and shut off any
other fuel-gas-buming appliance within the same
room. Use the shutoff valve in the supply line
to each appliance.
4. Inspect burners and crossovers for blockage and
corrosion.
5. Applicable only to furnaces. Inspect the heat
exchanger for cracks, openings, or excessive cor-
rosion.
6. Apphcable only to boilers. Inspect for evidence
of water or combustion product leaks.
7. Insofar as is practical, close all building doors
and windows and all doors between the space in
which the appliance is located and other spaces of
the building. Turn on clothes dryers. Turn on any
exhaust fans, such as range hoods and bathroom
exhausts, so they will operate at maximum speed.
Do not operate a summer exhaust fan. Close fire-
place dampers. If, after completing Steps 8
through 13, it is believed sufficient combustion
air is not available, refer to Section C304 of this
code for guidance.
8. Place the appliance being inspected in operation.
Follow the lighting instructions. Adjust the
thermostat so appliance will operate continu-
ously.
9. Determine that the pilot(s), where provided, is
burning properly and that the main burner igni-
tion is satisfactory by interrupting and reestab-
lishing the electrical supply to the appliance in
any convenient manner. If the appliance is
equipped with a continuous pilot(s), test the pilot
safety device(s) to determine if it is operating
properly by extinguishing the pilot(s) when the
main bumer(s) is off and determining, after 3
minutes, that the main burner gas does not flow
upon a call for heat. If the appliance is not pro-
vided with a pilot(s), test for proper operation of
the ignition system in accordance with the appli-
ance manufacturer's lighting and operating in-
structions.
10. Visually determine that the main burner gas is
burning properly (i.e., no floating, lifting, or flash-
back). Adjust the primary air shutter(s) as re-
quired. If the appliance is equipped with high and
low flame controlling or flame modulation, check
for proper main burner operation at low flame.
1 1 . Test for spillage at the draft hood relief opening
after 5 minutes of main burner operation. Use a
flame of a match or candle or smoke.
12. Turn on all other fuel-gas-buming appliances
within the same room so they will operate at their
full inputs. Follow hghting instructions for
each appliance.
1 3 . Repeat Steps 1 and 1 1 on the appliance being in-
spected.
14. Return doors, windows, exhaust fans, fireplace
dampers, and any other fuel-gas-buming appli-
ance to their previous conditions of use.
15. Applicable only to furnaces. Check both the
limit control and the fan control for proper opera-
tion. Limit control operation can be checked by
blocking the circulating air inlet or temporarily
disconnecting the electrical supply to the blower
motor and determining that the limit control acts
to shut off the main bumer gas.
16. Apphcable only to boilers. Determine that the
water pumps are in operating condition. Test low
water cutoffs, automatic feed controls, pressure
and temperature limit controls, and relief valves
in accordance with the manufacturer's recom-
mendations to determine that they are in operat-
ing condition.
2007 OREGON MECHANICAL SPECIALTY CODE
117.139
117.140 2007 OREGON WJECHANICAL SPECIALTY CODE
•
INDEX FOR CHAPTERS 1-14
•
A
ADMINISTRATION AND ENFORCEMENT. . Chapter 1
AIR
Combustion Chapter 7
Distribution systems Chapter 6
Filters 605
Transfer 403.2.2
Supply Chapter 4
Ventilation Chapter 4
ALTERNATIVE MATERIAL 105.2
AMMONIA 1105.10, 1106.8
APPEAL 109
APPLIANCES
Access 306
Hazardous location 303.2
Installation Chapters 3, 9
Outdoors 303.6
Prohibited locations 303
APPLICABILITY OF CODE 102
APPROVAL 105
ATTIC VENTILATION 406
AUTOMATIC DAMPERS 803.6
AUTOMATIC FIRE SUPPRESSION,
KITCHEN EXHAUST 509
B
BARBECUE APPLIANCES 906
BATHROOM VENTILATION 402, 403
BLOWOFF VALVE, STEAM 1008
BOILERS Chapter 1
BURNER, CONVERSION 919
c
CANOPY HOODS 507.12, 507.13
CEILING DAMPERS 607
CHILLED WATER PIPING Chapter 12
CHIMNEYS AND VENTS
Connectors 803
Dampers 803.5, 803.6
Direct Vents 804.1
Exhausters 804.3
Existing 801.18
Factory built 802, 805
General 801
Masonry, general 801
Vents 802
CLEANOUTS
Kitchen exhaust 506.3.9, 506.3.10
Masonry chimneys 801.13
CLEARANCES
Appliance in garages 304.5, 304.6
Chimney and vent 801 .1 8.4
Connectors 803.10.6
Kitchen exhaust . 506.3.6, 507.9
Reduction 308
Specific appliances Chapter 9
CLOTHES DRYER
Appliance 913
Exhaust 504
COAL-BURNING APPLIANCES Chapter 9
CODE OFFICIAL 104, 202
COLLECTORS, SOLAR 1402.4, 1404.1
COMBUSTIBLE LIQUID STORAGE TANK 1301
COMBUSTIBLES, REDUCED CLEARANCE 308
COMBUSTION AIR Chapter 7
COMMERCIAL KITCHEN EXHAUST 506
Hoods 507
CONDENSATE DISPOSAL 307
CONDENSATION
Ducts 603.12
Piping 1107.3
CONNECTORS, CHIMNEY OR VENT 803
CONTAMINANTS, VENTILATION AIR . 401 .4.1 , 401 .6
CONVERSION BURNERS 919
CONVEYOR SYSTEMS 51 1
COOKING APPLIANCES 917
COOLING TOWERS 908
COOLING WATER PIPING Chapter 12
COVERING, DUCT 604.3
CRAWL SPACE PLENUMS 602
CRAWL SPACE, VENTILATION 406
CREMATORIES 907
CUTTING, NOTCHING, BORING 302
D
DAMPERS
Chimney or vent 803.5, 803.6
Combustion air 709
Fire 607
Smoke 607
DEFINITIONS Chapter 2
DETECTORS, DUCT 606
DOCUMENTS 106.3.1
DRYER, CLOTHES
Exhaust 504
General 913
2007 OREGON MECHANICAL SPECIALTY CODE
118
INDEX
DUCT
Combustion air 708
Construction 603
Co ering 60 .3
etectors smoke 606
nclosure 506.3.10 510.
xhaust 501 .
ire damper 607
lexible 603.6
urnace 18
angers and supports 603.10
a ardous exhaust 510
nstallation 603
nsulation 60
Joints 603.
itchen exhaust 506
Lining 60 .3
Plastic 603.8.3
i ing 603.2
moke damper 607
stems Chapter 6
Underground 603.8
DUST, STOCK AMD REFUSE
CONVEYOR SYSTEiiS 51 1
E
ELECTRDC ilMSTALLATlOiSJ 301 .7
ENERGY EFFICIEIMCY 301.2
ENERGY RECOVERY SYSTEMS 51
ENGINE/TURBINE EQUIPMENT 15
EQUIPMENT ACCESS 306
EQUiPMENT IDENTIFICATION 30 .11
EXHAUST, REQUIRED SYSTEMS 502
Clothes dr er 50
ischarge 501 .2
ucts 501.
itchen 505 506 507
achiner room 1 1 05 1 1 06
echanical 03 Chapter 5
penings 01 . 01 .5
stem ha ardous 510
EXHAUSTER • 80
EXISTDNG SYSTEMS 102.2
F
FACTORY BUILT
Barbecue appliance 06
Chimne s 805
Commercial exhaust hoods 507.1
ucts (kitchen exhaust) 506.3.1 .1
506.3.2 506.3.6
ireplaces 03
FANS, EXHAUST 503 506.5.1
FILTERS, AIR 605
FILTERS, GREASE 507.1 1
FIRE DAMPERS ' 607
FIRE SUPPRESSION
a ardous exhaust 510.7
itchen exhaust 50
FIREPLACES
actor built. . 03
asonr 02.1
FIREPLACE STOVE 05
FLEXIBLE CONNECTORS (DUCT) 603.6 607.7
FLEXIBLE CONNECTORS, HYDRONIC 1202.7
FLEXIBLE DUCTS. . 603.6 607.7
FLOODHAZARD 301.13 01. .3 602. 603.13
FLOOR FURNACE 10
FLUE LINERS 801.16 801.18.2
FUEL CELLS 2
FUEL, CONVERSION . .301 .
FUEL OIL
Piping Chapter 1 3
Piping installation 1305
Piping material 1302
FURNACE, FORCED-AIR 18
FURNACE ROOM 30 .7
G
GAUGES, BOILERS 1010
GREASE 506 507
GREASE FILTERS 507.11
GUARDS 30 .10
HANGERS, PIPE 305
HAZARDOUS EXHAUST SYSTEM 510
HAZARDOUS LOCATION,
EQUIPMENT 30 .3 01.3
HAZARDOUS LOCATION, INSTALLATION .... 30 .3
HEATER Chapter
HEAT PUMP 1,8.3
HOOD DESIGN (KITCHEN) 507
HOOD, EXHAUST 505 506 507 510.5.3
HOT WATER BOILERS Chapter 10
HOT WATER PIPING Chapter 12
HYDROGEN GENERATION
AND REFUELING 30 . 26
HYDRONIC PIPING Chapter 12
INCINERATORS 07
INSIDE AIR, COMBUSTION '. Chapter 7
INSPECTION . .107
INSULATION
uct 60
Pipe 120
119
2007 OREGON WiECHANICAL SPECIALTY CODE
INDEX
•
•
JOINTS
Connectors 803.10.1
uct 506.3.2 510.8.1 603.
Piping 1003.2 1107.5 1203 1303
K
KEROSENE STOVE 22
KILNS 23
KITCHEN EXHAUST EQUIPMENT Chapter 5
LABELING
Criteria for 301 . 301 .5 301 .6
LINER, FLUE 801.16
LINING, DUCT . .60 .3
LISTING 301.
LOCATION, EQUIPMENT AND APPLIANCE. ... 303
LOW-WATER CUTOFF, BOILER. . 1007
M
MACHINERY ROOMS . .. 110 .2 1105 1106
MAKEUP AIR, EXHAUST . 508 510.5.5
MAKEUP WATER 08.5 1005.2 1206.3 1207.2
MASONRY CHIMNEYS Chapter 8
MASONRY FIREPLACE 02
MECHANICAL EXHAUST/DRAFT 80
MECHANICAL OFFICIAL (see CODE OFFICIAL)
MECHANICAL REFRIGERATION Chapter 11
MECHANICAL VENTILATION 30 . .2 03
MOTORS 503 506.5.1 .1
MOVED STRUCTURE 102.7
NATURAL VENTILATION 30 . .1 02
NONCANOPY HOODS 507 1
OIL, FUEL PIPING Chapter 13
OPENINGS
Combustion air Chapter 7
utside 01 . 01 .5
OUTDOOR AIR, COMBUSTION Chapter 7
OUTDOOR INSTALLATION 303.6
OUTSIDE AIR, MINIMUM 03
PELLET FUEL-BURNING APPLIANCES. .
PENETRATIONS 302.2 607
PERMITS 106
PIPE
nsulation 1107.3 120
upport 305
PIPING
uel oil Chapter 13
aterial fuel oil 1302
aterial h dronic 1202
efrigerant 1 1 07
upport 305
PLENUMS 602
PLUMBING 301.8
POOL/SPA HEATER .... 16
POWER EXHAUSTER. . . .80
PRESSURE GAUGE 1010
PRESSURE VESSEL 1003
R
RADIANT HEATER 12
RANGE HOODS .... Chapter 5
REDUCED, CLEARANCE 308
REFRIGERANT PIPING 1107
REFRIGERANT, QUANTITY 110
REFRIGERATION, MECHANICAL Chapter 1 1
REGISTERS 603.17
RELIEF VALVES, FUEL OIL 1307
RELIEF VALVES, PRESSURE VESSELS 1006
RELIEF VALVES, SOLAR 1 02.5.1
REPAIRS 102.
ROOM HEATERS, SOLID FUEL 05 21
S
SAFETY VALVE 1006
SAUNA HEATER 1
SCOPE OF CODE .101.2
SEISMIC 301.15
SIGHT GLASS.. 1010
SMOKE CONTROL 513
SMOKE DAMPERS 607
SMOKE DETECTORS 606
SOLAR Chapter 1
SOLID FUEL-BURNING APPLIANCES .... Chapter
STANDARDS, REFERENCED 102.8 Chapter 15
STEAM
Blowoff 1008
Boilers Chapter 10
auge. .1010
Piping Chapters 10 12
SUBSLAB SOIL EXHAUST SYSTEM ... 512
SUPPORTS, DUCT. 603.10
SUPPORTS, PIPING 305
2007 OREGON MECHANICAL SPECIALTY CODE
120
DNDEX
SUPPRESSION
a ardous exhaust 510.7
itchen exhaust 50
T
SIOM 100 1 02.5.
lABLE AND
E LIQUBDS Chapter 13
TEMPERATURE GAUGE 1010
TEMPERATURE RELIEF, SOLAR 1 02.
TESTS,
Boiler/pressure essel 101 1
uel oil piping 1 308
dronic piping 1208 120 .2
itchen exhaust 507.16
ef rigeration 1 1 08
THERIiAL STORAGE, SOLAR 1 .2
TOILET ROOM VENTILATION 02.1 Table 03.3
JSFER FLUID
dronic piping 1207
olar 1 03
y
PERGROUND STORAGE TANKS Chapter 13
r HEATER 20
)AFE CONDITIONS 108
UTED GAS LOG HEATERS 03.3
Boilers 1005 1008
uel oil 1307
dronic 1205
afet and relief 1 006
top 1107.7
VAPOR RETARDER 60 .11
VENTILATION
Air Chapter
nerg reco er s stems 51
achiner room 1 1 05 1 1 06
echanical 30 . .2 03
Natural 30 . .1 02
penings 01 . 01 .5
ate 03.3
ecirculation 03.2.1
Transfer 03.2.2
Uninhabited spaces 06
VENTS
Connectors 803
irect 80
eneral 802 Chapter 8
eight 802.6
Termination 802
ROL DEVICES 301.10
108
WALL FURNACE
"ER HEATERS 1002
■ER PIPING Chapter 12
RESISTANCE 301.12
J-BURNING APPLIANCES Chapter
•
•
121
2007 OREGON MECHANICAL SPECJALTY CODE
•
•
2007 OREGON MECHANICAL SPECIALTY CODE 1 22
INDEX FOR APPENDIX C
Duct furnaces C610.3
General C306
Shutoff valves C409.1 .3, C409.3.1 , C409.5
Wall furnaces, vented C608.6
ilMISTRATIOM Chapter 1
Alternate materials and methods 105.2
Alternate methods of sizing chimneys . . C503.5.5
Appeals 1 09
Duties and powers of code official 1 04
Fees 106.5
Inspections 104.4, 107, C102
Liability 103
Permits 106
Plan review 106.5.4
Severability 101.4
Scope 101.2
Title 101.1
Violations and penalties 108
Defined C202
Requirements C303.3, C304
COMDITIONING EQUIPMEMT C627
Clearances C308.3
DVIETHODS 105.2
^PLIANCES
Broilers for indoor use C623.5
Connections to building piping C41 1
Cooking C623
Decorative C602
Decorative vented C202, C303.3,
Table C503.4, C604
Domestic ranges C623.4
Electrical C309
Installation Section 6
Prohibited locations C303.3
Protection from damage C303.4
,C405
BOILERS
Existing installations Appendix C-D
Listed C631
Prohibited locations C303.3
BUSHINGS C403.9.4, C404.3
C
CENTRAL FURNACES
Defined C202
Existing installation Appendix C-D
CHIMNEYS Section 5
Alternate methods of sizing C503.5.5
Clearance reduction C308
Damper opening area C634
Defined C202
CLEARANCE REDUCTION C308
CLEARANCES
Air-conditioning equipment C627.4
Domestic ranges C623.4
Floor furnaces C609.4, C609.6
Open-top broiler units C623.5.1
Refrigerators C625.1
Unit heater C620.4
CLOTHES DRYERS
Defined 202
Exhaust C614
General C613
CODE OFFICIAL
Defined 202
Duties and powers 1 04
COMBUSTION AIR
Combination indoor and outdoor C304.7
Defined C202
Exhaust effect C304.4
Free area .... C304.5.3.1, C304.5.3.2, C304.6.1,
C304.6.2, C304.10
Horizontal ducts C304.6.1
Indoor C304.5
Outdoor C304.6
Sauna heaters C61 5.5
Sources of (from) C304.1 1
Vertical ducts C304.6.1
COMPRESSED NATURAL GAS C413
CONCEALED PIPING C404.2
CONDENSATE DISPOSAL C307
CONTROLS
Gas pressure regulators C410.1, C628.4
CONVERSION BURNERS C503.12.1, C619
COOKING APPLIANCES C623
CORROSION PROTECTION C404.8
•
123
2007 OREGON MECHANICAL SPECIALTY CODE
INDEX
•
CREMATORIES C606
CUTTING, NOTCHING, AND
BORED HOLES C302.3
DAMPERS, VENT C503.14
DECORATIVE APPLIANCES C602
DEFINITIONS 0202, Chapter 2
DIRECT VENT APPLIANCES
Defined . C202
Installation .0304.1
DITCH FOR PIPING O404.10.1, 107.1(1)
DIVERSITY FACTOR 0402.2, Appendix 0-A
DRAFT HOODS O202, 0503.12
DUCT FURNACES O202, 0610
ELECTRICAL CONNECTIONS O309.2
EXHAUST SYSTEMS . 0202,0503.2.1, 0503.3.4
INSTALLATION, APPLIANCES
Garage O305
General 0301
Listed and unlisted appliances . . . O301 .3, O305.1
Specific appliances Section 6
K
KILNS .0629
LIQUEFIED PETROLEUM GAS
Defined 0202
Motor vehicle fuel-dispensing stations ..... 0412
Piping nnaterial O403.6.2, O403.1 1
Size of pipe or tubing Appendix 0-A
Storage 0401 .2
Systems 0402.6.1
Thread compounds O403.9.3
LOG LIGHTERS O603
•
FEES 104.8, 106.4, 106.5
FLOOD HAZARD 301.13
FLOOR FURNACES 0609
FURNACES
Central heating, clearance 0308.3, O308.4
Duct O610
Floor 0609
Prohibited location O303.3
Vented wall 0608
G
GARAGE, INSTALLATION . . . 0305.3, O305.4, O305.5
GASEOUS HYDROGEN SYSTEMS 0635
General requirements 0703
Piping, use and handling. 0704
Testing O705
GROUNDING, PIPE O309.1
H
HISTORIC BUILDINGS . . 102.6
HOT PLATES AND LAUNDRY
STOVES 0501 .8, 0623.1
ILLUMINATING APPLIANCES 0628
INCINERATORS O606, O607
INFRARED RADIANT HEATERS 0630
INSPECTIONS 104.4, 104.8, 107, 0102
M
MAKE-UP AIR HEATERS 0611, 0612
Industrial 0612
Venting 0501 .8
MATERIALS, DEFECTIVE
Repair 0301.9
Workmanship and defects 0403.7
METERS
Interconnections 0401 .6
Identification O401 .7
Multiple installations 0401.6
MINIMUM SAFE PERFORMANCE,
VENT SYSTEMS 0503.3
OUTLET CLOSURES 0404.12
Location O404.1 3
OVERPRESSURE PROTECTION . . 0416
OXYGEN DEPLETION SYSTEM
Defined O202
Unvented room heaters 0303.3(3), 0621.6
PIPE SIZING . .0402
PIPING
Bends 0405
Changes in direction O405
Drips and slopes 0408
Installation 0404
2007 OREGON MECHANICAL SPECIALTY CODE
124
INDEX
Inspection C406
Materials C403
Purging C406.7
Sizing C402
Support C407, C41 5
Testing C406
POOL HEATERS C617
POWERS AND DUTIES OF
THE CODE OFFICIAL 104
PROHIBITED INSTALLATIONS
Floor furnaces C609.2
Fuel-burning appliances C303.3
Piping in partitions C404.2
Plastic piping C404.14.1
Unvented room heater C621 .4
Vent connectors 0503.3.3
PURGING C406.7
R
RADIASSIT HEATERS C630
IGES, DOMESTIC C623.4
oERATORS C501 .8, C625
IS, PRESSURE C410.1 , C628.4
TALLATIONS C306.5
m HEATERS
Defined C202
Location C303.3
Unvented C621
Vented C622
ETY SHUTOFF DEVICES
Flame safeguard device C602.2
Unvented room heaters 0621 .6
lEATERS 0615
^OPE 101.2
llSIVlie RESISTANCE 301.15
■RV8CE SPACE 0306
^A HEATERS 0617
Chapter 15
PCTURAL SAFETY 0302.1
PING 0407,0415
T
"ESTING 107,0102
1BLE,VENT 0503.10.11,0503.10.15
EADS
Damaged O403.9.1
Specifications 0403.9
0626
HEATERS O620
UNLISTED BOILERS ... 0632
UNVENTED ROOM HEATERS 0621
V
VALIDITY 106.4.2
VALVES, MULTIPLE
HOUSE LINES O409.3
VALVES, SHUTOFF 0409
VENTILATING HOODS 0503.2.1,0503.3.4
VENTED DECORATIVE
APPLIANCES 0604
VENTED ROOM HEATERS 0622
VENTED WALL FURNACES 0608
VENTS
Caps O503.6.6
Direct vent 0503.2.3
Equipment not requiring vents 0501 .8
Gas vent termination O503.6.4
General Section 5
Integral O505
Listed and labeled O502.1
Mechanical vent O505
VENT, SIZING
Category I appliances O502, 0503, O504
Multi-appliance 0504.3
Multistory O504.3.13, 0504.3.14,
0504.3.15,0504.3.16
Single appliance 0504.2
VIBRATION ISOLATION 301.10
VIOLATIONS AND PENALTIES 108
w
WALL FURNACES, VENTED 0608
WARM AIR FURNACES 0618
WATER HEATERS 0624
WIND RESISTANCE 301.12
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125
2007 OREGON MECHANICAL SPECIALTY CODE
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