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§ 5:23-3.15 Plumbing subcode

(a) Rules concerning subcode adopted are as follows:

1. Pursuant to authority of P.L. 1975, c. 217, as modified by P.L. 1996, c. 53, the Commissioner hereby
adopts the Model Code of the National Association of Plumbing Heating-Cooling Contractors, known as "The
National Standard Plumbing Code/2006," as the plumbing subcode for New Jersey.

i. Copies of this code may be obtained from the sponsor at: NAPHCC, P.O. Box 6808, Falls Church, VA
22046.

2. "The National Standard Plumbing Code/2006," including appendices, may be known and cited as "the
plumbing subcode."

(b) The following pages, chapters, sections or appendices of the plumbing subcode shall be amended as
follows:

1. The section entitled "Administration," comprising sections ADM 1.1 through ADM 1.13, is deleted in its
entirety.

2. Chapter 1 of the plumbing subcode, entitled "Definitions," shall be amended as follows:
i. Delete the term and definition of "Adopting Agency."

ii. Amend the definition of "approved" as follows: delete "Sec. 3.12" and insert " 5:23-3.7 ."

iii. Delete the definition of "Authority Having Jurisdiction" and insert the following: "Unless otherwise
defined herein, or unless the context clearly indicates otherwise, the term "authority having jurisdiction" for
purposes of the plumbing subcode, shall mean the "plumbing subcode official."

iv. The definition of the term "building" is deleted, and substitute in lieu thereof, the definition of the term
"building" found in 5:23-1.4 .

v. In the definition of "Building Classification" delete "authority having jurisdiction" and insert "building
subcode" at 5:23-3.14 .

vi. The term and definition of "code" are deleted.

vii. The term and definition of "family" are deleted.

viii. The definition of "hot water" shall be deleted and the following definition shall be inserted: "Hot Water:
Potable water at a temperature of not less than 120 degrees F and not more than 140 degrees F.

ix. The definition of "tempered water" shall be deleted and the following definition shall be inserted:
"Tempered Water: Water at a temperature of not less than 90 degrees F and not more than 105 degrees F.

x. The term and definition of "nuisance" are deleted.

xi. Add the following new definition after the definition of Swimming Pool: Swimming Pool, Public: A
swimming pool located on any property other than a one or two family residential property and including, but
not limited to, swimming pools open to the use of members, residents or the public.

3. Chapter 2 of the plumbing subcode, entitled "General Regulations," shall be amended as follows:

i. Section 2.5 is deleted in its entirety.

ii. In Section 2.9.3 delete "Building Code or as required by the proper Authority Having Jurisdiction" and
insert "building subcode."

iii. In Section 2.11, Piping materials exposed within plenums, "Codes" shall be deleted and "subcodes" shall
be inserted.

iv. In Section 2.12, Sleeves, subparagraph e, "regulations" shall be deleted and "subcode" shall be inserted.

v. In Section 2.16, Freezing or overheating, at item 1, "42" shall be inserted in the blank space provided.
Additionally, the following sentence shall be inserted: "Combination domestic/fire water service piping shall be
installed such that the minimum earth cover is 42 inches or the top of the pipe is 12 inches below the frost depth
of the locality, whichever is greater. Limited-area sprinkler systems installed in accordance with Section
903.3.5.1.1 of the building Subcode, shall be installed such that the minimum earth cover is 42 inches." In the
same section, at Item 2, "24" shall be inserted in the blank space provided. In addition, in the second line of
Item 2, "6" shall be inserted in the blank space provided.

vi. Section 2.19.1 is amended to delete the blank and the words "feet of any property line of the premises, or
other. "

vii. Section 2.19.2 is amended to delete the words "the Health Department or other agency having
jurisdiction" and substitute in lieu thereof "The New Jersey Department of Environmental Protection."

viii. In Section 2.25, at Item 8, insert "and which does not otherwise adversely affect health and safety" at the
end of the section.

4. Chapter 3 of the plumbing subcode, entitled "Materials," shall be amended as follows:

i. In Section 3.1.1 delete "Minimum." In the same section at items (1) and (2), delete "Section 3.12.2" and
insert " 5:23-3.7 ."

ii. In Section 3.1.2, at Item a, delete "at least." In the same section, delete "Section 3.12" and insert "

5:23-3.7 ."

iii. In Section 3.1.3, Standards applicable to plumbing materials, "Section 3.12.2" shall be deleted and "
5:23-3.7 " shall be inserted.

iv. Section 3.3.8a is amended to add the following phrase: "Pressure vessels shall be designed and
constructed in accordance with the requirements of American Society of Mechanical Engineers, (ASME), Rules
for Construction of Pressure Vessels, Section VIII/1998. Any pressure vessel that exceeds any of the following,
shall meet the requirements of ASME and shall be stamped ASME: A heat input rating of 200,000 BTU per
hour; or a water temperature of 200 degrees Fahrenheit; or a nominal water capacity of 120 gallons or any other
thresholds of ASME that apply."

v. Section 3.3.11 entitled "Septic Tanks" is deleted in its entirety.

vi. Add new section 3.4.2.1 as follows: 3.4.2.1 Combination Domestic/Fire Water Service: Water service
piping for combination domestic/fire water services shall be of materials listed in Table 3.4 and shall be water
pressure rated not less than 200 psig at 73 [degrees] F. Joint restraints shall comply with Section 6.3, entitled
"Joint Restraint for Fire Mains" per NFPA 13.

Exception: Limited area sprinkler systems installed in accordance with Section 903.3.5.1.1 of the building
subcode, shall be water pressure rated not less than 160 psig at 73 [degrees] F.

vii. In Section 3.11.1 delete "approved by the Authority Having Jurisdiction."

viii. In Section 3.11.2 delete "except as may be otherwise authorized by the Authority Having Jurisdiction."

ix. Section 3.12, Alternate materials and methods, shall be deleted in its entirety.

5. Chapter 4 of the plumbing subcode entitled, "Joints and Connections" is amended as follows:

i. In Section 4.3.8(b)(3) delete "be approved by the Authority Having Jurisdiction if such products are not
listed or labeled" and insert "or as permitted under 5:23-3.7 ."

6. Chapter 5 of the plumbing subcode entitled, "Traps, Cleanouts and Backwater Valves," shall be amended
as follows:

i. In Section 5.3.2, Trap seals, in Exception (2), "in accordance with 5:23-3.3 " shall be inserted after
"Authority Having Jurisdiction."

ii. In Section 5.3.4, Building traps, "in accordance with 5:23-3.3 " shall be inserted after "Authority Having
Jurisdiction."

7. Chapter 6 of the plumbing subcode, entitled "Liquid Waste Treatment Equipment," shall be amended as
follows:

i. At the end of Section 6.1.1, Where required, the following shall be inserted: "The determination of
necessity shall be made by the plumbing subcode official in accordance with 5:23-3.3 ."

ii. Section 6.4.4 is amended to add the phrase "in accordance with 5:23-3.3 " after the word "approval" on
line 2.

8. Chapter 7 of the plumbing subcode, entitled "Plumbing Fixtures, Fixture Fittings and Plumbing
Appliances," shall be amended as follows:

i. Section 7.2 is amended to read "Plumbing fixtures for accessible use and their installation shall conform to
the requirements of 5:23-7 et. seq."

ii. In Section 7.4.4, Bowl height, Exception (2) and Exception (3) shall be deleted and the following text
shall be inserted: "Accessible water closets shall conform to the requirements of 5:23-7 et seq."

iii. At the end of Section 7.18.2 after "Authority Having Jurisdiction" insert "in accordance with 5:23-3.3 ."

iv Note 1 to Table 7.21.1 is amended to delete the words "For handicap requirements see local, state, or
national codes." in the second sentence.

v. Figure 7.3.2 is amended to delete the word "Code" and substitute in lieu thereof "Subcode" in the block at
bottom.

vi. Section 7.23, Safety features for spas and hot tubs, shall be deleted and Section 7.23, Safety features for
swimming pools, spas and hot tubs, shall be inserted as follows:

"7.23 Safety Features for Swimming Pools, spas and hot tubs.

7.23.1 General. Suction outlets shall be designed to provide circulation throughout the pool, spa or hot tub.
Single-outlet systems, such as automatic vacuum cleaner systems, or other such multiple suction outlets

whether isolated by valves or otherwise, shall be protected against user entrapment.

7.23.2 Suction fittings. All pool and spa suction outlets shall have a cover that conforms to ASME
A112.19.8M, a 18-inch by 23-inch (457 mm by 584 mm) drain grate or larger, or an approved channel drain
system.

Exception: Surface skimmers.

7.23.3 Atmospheric vacuum relief system required. Pool and spa single- or multiple-outlet circulation
systems shall be equipped with atmospheric vacuum relief should grate covers located therein become missing
or broken. This vacuum relief system shall include at least one approved or engineered method of the type
specified herein, as follows:

1. Safety vacuum release system conforming to ASME A112.19.17;or

2. Approved gravity drainage system

7.23.4 Dual drain separation. Single- or multiple-pump circulation systems shall have a minimum of two
suction outlets of the approved type. A minimum horizontal or vertical distance of 3 feet (914 mm) shall
separate such outlets. The suction outlets shall be piped so that water is drawn through the outlets
simultaneously through a vacuum- relief-protected line to the pump or pumps.

7.23.4.1 All swimming pools shall be equipped with main drain suction outlets in the lowest point of the
swimming pool floor. The spacing of the main drain suction outlets shall not be greater than 20 feet on center,
nor more than 15 feet from each side wall.

7.23.5 Pool cleaner fittings. Where provided, vacuum or pressure cleaner fitting(s) shall be located in an
accessible position(s) at least 6 inches (152 mm) and not more than 12 inches (305 mm) below the minimum
operational water level or as an attachment to the skimmer(s).

9. Chapter 8 of the plumbing subcode, entitled "Hangers and Supports," shall be amended as follows:

i. In Section 8.9, Seismic supports for piping, "code" shall be deleted and "subcode" shall be inserted.

10. Chapter 10 of the plumbing subcode, entitled "Water Supply and Distribution," shall be amended as
follows:

i. In Section 10.2 after "Authority Having Jurisdiction" insert "in accordance with 5:23-3.3 ".

ii. In Section 10.4.2 delete "with the approval of the Authority Having Jurisdiction" and insert "in
accordance with the rules of the New Jersey Department of Environmental Protection at 7: 10-10";

iii. Section 10.4.3 is amended to read: "Potable water supplies shall be protected in accordance with the
provisions of this code and where applicable the Safe Drinking Water Regulations ( 7:10 ). The requirements of
this code shall establish requirements for individual outlet protection. The requirements of the Safe Drinking
Water Act shall establish the requirements for containment.";

iv In Section 10.4.4, Private supplies, at Note b, "in accordance with 7:10-10.2 (e)" shall be inserted after
"Authority Having Jurisdiction."

v. Section 10.5.6d. is amended to delete the words "and repair" on the first line, and to delete the third
sentence.

vi. In Section 10.8.1 insert "as required by the Authority Having Jurisdiction" after "in accordance with good
practice."

vii. Section 10.15.1, Hot water supply system, shall be amended to add the phrase "Outlet temperature of hot
water from lavatory faucets in public facility restrooms (such as those in service stations, airports, train and bus
terminals, and conventions halls) shall be provided with a means to limit the maximum temperature to 110
degrees F. as required in ASHRAE 90.1-1999."

11. Chapter 11 of the plumbing subcode, entitled "Sanitary Drainage Systems," is amended as follows:

i. Section 11.4.3 is amended at the end to add the sentence "Diversity factors shall be established in
accordance with 5:23-3.3 ."

12. Chapter 12 of the plumbing subcode, entitled "Vents and Venting," shall be amended as follows:
i. Section 12.5 is deleted in its entirety.

ii. Section 12.8.2 is deleted in its entirety.

13. Chapter 13 of the plumbing subcode, entitled "Storm Water Drainage," shall be amended as follows:

i. In Section 13.1.5, Foundation drains, Notes a. through c. shall be amended to read "subsoil drains shall be
provided in accordance with the building subcode."

ii. Section 13.1.10.1, Primary roof drainage, shall be amended to delete the last sentence and to substitute in
lieu thereof "Rainfall rates shall be applied so that the applicable rainfall rate for Burlington and Ocean counties
and all counties south shall be six inches per hour and for Mercer and Monmouth counties and all counties
north, the applicable rainfall rate shall be five inches per hour."

iii. Section 13.1.10.2, "Secondary Roof Drainage," is deleted.

iv. Section 13.1.10.4, "Equivalent Systems," is deleted.

v. In Section 13.9.1 after "Authority Having Jurisdiction" insert "in accordance with 5:23-3.3 ."

14. Chapter 15 of the plumbing subcode, entitled "Tests and Maintenance" is amended as follows:

i. Add new Section 15.6.1 as follows: 15.6.1 Combination Domestic/Fire Water Service Systems: Piping for
combination domestic/fire water services systems shall be pressure tested to not less than 200 psig and shall
maintain that pressure without loss for 2 hours.

ii. Add new Section 15.6.1.1 as follows: 15.6.1.1 Leakage: The following provisions shall apply to buried
pipe in all combination domestic/fire water service systems, except for limited sprinkler systems:

(1) The amount of leakage at the joints shall be no greater than 2 qt/hr (1.89 L/hr) per 100 joints or gaskets,
regardless of pipe diameter.

(2) The amount of leakage in accordance with (1) above shall be permitted to be increased in increments of 1
fluid ounce (30 ml) per inch valve diameter per hour for each metal seated valve that isolates the test section.

(3) The amount of leakage in buried piping shall be measured at the test pressure specified by pumping from
a calibrated container.

iii. Add new Section 15.9 as follows: 15.9 Flushing of Piping: Lead-in connections to system risers and fire
service mains from the water supply to the system riser (excluding limited systems) shall be flushed completely
before connection is made to sprinkler piping. The flushing operation shall be continued for a sufficient amount
of time to ensure that the system is thoroughly cleaned. The minimum rate of flow shall be not less than one of
the following:

(1) The hydraulically calculated water demand rate of the system, including any hose requirements.

(2) The flow that is necessary to provide a velocity of 10 ft/sec (3.1 m/sec).

(3) The maximum flow rate available to the system under fire conditions.

15. Chapter 16 of the plumbing subcode, entitled "Regulations Governing Individual Sewage Disposal
Systems for Homes and Other Establishments Where Public Sewer Systems Are Not Available," shall be
amended as follows:

i. Except as otherwise indicated in (b)15ii below, Sections 16.1 through 16.12.1.13 shall be deleted in their
entirety.

ii. Section 16.1.7, Abandoned disposal systems, shall be retained and amended to read as follows: "When an
existing sewage disposal system is being abandoned and a connection is being made to the public sewer system
or new sewage disposal system, the plumbing subcode official shall ensure that the existing abandoned tank is
disconnected from the building, pumped out and filled with gravel, stones or soil material."

Note: Existing standards of the Department of Environmental Protection and boards of health with respect to
individual on-site sewage disposal systems remain in effect.

16. Chapter 17 of the plumbing subcode entitled, "Potable Water Supply Systems," shall be deleted in its
entirety.

Note: Existing standards of the Department of Environmental Protection and boards of health with respect to
individual on-site water supply systems remain in effect.

17. Chapter 18 of the plumbing subcode, entitled "Mobile Home and Travel Trailer Park Plumbing
Standards," shall be amended as follows:

i. In Section 18.2.1, General, the last sentence beginning with "Trailer home park" shall be deleted.

ii. Section 18.2.2 is amended to delete the words "or sewerage disposal" on line 1.

iii. Section 18.5.8 is amended to add the phrase "and as provided by the authority having jurisdiction" after
the words "chapter 10 of this code."

iv Section 18.8.1.2 is deleted.

v. Section 18.8.3 is amended to add the phrase "for dependent trailers" after the word "park" on line 1.

vi. Section 18.8.4 is amended to add the phrase "for dependent trailers" after the word "park" on line 1.

vii. Section 18.9 is deleted.

viii. Section 18.10 is deleted.

18. Appendix A, entitled "Sizing Storm Drainage Systems," shall be deleted in its entirety.

19. Appendix F, entitled "Requirements of the Authority Having Jurisdiction," shall be amended as follows.

i. In Section F.2, References, the following shall be deleted: "1.7.2 Penalties; 1.9.8 Permit Expiration; 1.10.2
Plan Review Fees; 1.10.3 Plan Review Expiration; 1.10.5 Refunding of Fees; and 1.11.5 Requests for
Inspection."

HISTORY

Amended by R.1981 d.132, effective May 7, 1981.

See: 13 N.J.R. 121(a), 13 N.J.R. 258(d).

Amended by R.1983 d.12, eff. February 7, 1983, operative February 22, 1983.

See: 14 N.J.R. 1326(a), 15 N.J.R. 141(c).

Added (a) 3 and (c).

Amended by R.1984 d.314, eff. August 6, 1984.

See: 16 N.J.R. 1139(a), 16 N.J.R. 2084(b).

Section substantially amended.

Amended by R.1986 d.12, effective February 3, 1986.

See: 17 N.J.R. 2714(a), 18 N.J.R. 267(a).

(a)li had a change of address; (a)3 and (c) added.

Amended by R.1987 d.81, effective February 2, 1987.

See: 18 N.J.R. 2237(b), 19 N.J.R. 289(d).

Amended by R.1987 d.374, effective September 21, 1987.

See: 19 N.J.R. 1024(a), 19 N.J.R. 1720(b).

Model subcode revisions.

Amended by R.1989 d.66, effective February 6, 1989.

See: 20 N.J.R. 2846(a), 21 N.J.R. 288(a).

Added (c).

Amended by R.1990 d.58, effective February 5, 1990.

See: 21 N.J.R. 3346(a), 22 N.J.R. 351(a).

Added (d) adopting the 1989 Supplement to the 1987 National Standard Plumbing Code.

Amended by R.1990 d.253, effective May 21, 1990.

See: 22 N.J.R. 909(b), 22 N.J.R. 1554(a).

Text added at (a)3; (d)3ii amended.

Amended by R.1990 d.507, effective October 15, 1990.

See: 22 N.J.R. 2208(a), 22 N.J.R. 3214(a).

Text conformed to BOCANational Code/1990.

Amended by R.1991 d.326, effective July 1, 1991.

See: 23 N.J.R. 804(a), 23 N.J.R. 2044(a).

GPF set at 1.6; gravity water closets not permitted in commercial uses.

Amended by R.1991 d.571, effective November 18, 1991.

See: 23 N.J.R. 2619(a), 23 N.J.R. 3444(b).

Added new (c).

Amended by R.1992 d.67, effective February 3, 1992.

See: 23 N.J.R. 3602(a), 24 N.J.R. 404(b).

Low volume water closet exception added at (b)18i(l).

Amended by R.1993 d.662, effective December 20, 1993.

See: 25 N.J.R. 3891(a), 25 N.J.R. 5918(a).

Amended by R.1995 d.122, effective March 6, 1995 (operative July 1, 1995).

See: 26 N.J.R. 4874(a), 27 N.J.R. 894(a).

Amended by R.1998 d.136, effective March 16, 1998.

See: 30 N.J.R. 4(a), 30 N.J.R. 1038(a).

In (b)9, added xii.

Amended by R.1998 d.332, effective July 6, 1998.

See: 30 N.J.R. 1377(a), 30 N.J.R. 2421(b).

Rewrote the section.

Amended by R.2001 d.340, effective September 17, 2001.

See: 33 N.J.R. 1245(a), 33 N.J.R. 3308(b).

Rewrote the section.

Amended by R.2002 d.393, effective December 16, 2002.

See: 34 N.J.R. 2914(a), 34 N.J.R. 4428(a).

In (b)8, deleted former (ii) and recodified existing (iii) to (ix) as (ii) to (viii).

Amended by R.2005 d.35, effective January 18, 2005.

See: 36 N.J.R. 3329(b), 37 N.J.R. 267(a).

Rewrote the section.

Administrative correction.

See: 37 N.J.R. 885(a).

Amended by R.2005 d.341, effective October 17, 2005.

See: 37 N.J.R. 164(a), 37 N.J.R. 3974(b).

In (b)3iv, added "and add the following sentence at the end: 'Minimum earth cover for building sewers
connected to a private sewage disposal system shall be 6 inches.'" at the end of the paragraph.

Amended by R.2007 d.65, effective February 20, 2007.

See: 38 N.J.R. 3348(a), 39 N.J.R. 633(a).

Rewrote the section.

Chapter Notes

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2006

NATIONAL STANDARD

PLUMBING CODE

ILLUSTRATED

PLUMBING HEATING COOLING
CONTRACTORS ASSOCIATION

Published By
PLUMBING-HEATING-COOLING CONTRACTORS-
NATIONAL ASSOCIATION

All inquiries or questions relating to interpretation should be forwarded to

Code Secretary

1 80 S. Washington St., P.O. Box 6808

Falls Church, V A 22046-1 148

1-800-813-7061

To order additional books call 1 -800-533-7694

(if callingfromNew Jersey call 1-800-652-7422)

Second Printing - November 2006

NATIONAL STANDARD

PLUMBING CODE

ILLUSTRATED

Title:

National Standard Plumbing Code Illustrated
Scope:

The development of a recommended code of plumbing practice, design, and installation,
including the establishment of performance criteria predicated on the need for protection of
health and safety through proper design, installation, and maintenance of plumbing systems.
This scope excludes the development of specific standards related to the composition,
dimensions, and/or mechanical and physical properties of materials, fixtures, devices, and
equipment used or installed in plumbing systems.

Purpose:

To provide practices and performance criteria for the protection of health and safety through
proper design of plumbing systems.

Exceptions:

In case of practical difficulty, unnecessary hardship or new developments, exceptions to the
literal requirements may be granted by the authority havingjurisdiction to permit the use of
other devices or methods, but only when it is clearly evident that equivalent protection is
thereby secured.

FOREWORD

Since its founding as the National Association of Master Plumbers in 1883, the National Asso-
ciation of Plumbing-Heating-Cooling Contractors has maintained a serious interest in plumbing
standards, codes and good plumbing design practices.

The Association published the NAMP "Standard Plumbing Code" in 1933 and furnished revised
editions until 1942. NAPHCC participated in the development of special standards for war-time
plumbing and later was represented on the National Plumbing Code Coordinating Committee,
whose work ultimately resulted in the adoption of A40.8 as a standard or model plumbing code in
1955.

NAPHCC served as a sponsor in the early 1960's of the project which attempted to update the
1955 document. This project was operated through the procedures of the American National
Standards Institute. However, the A40.8 revision project was not completed because consensus
could not be achieved.

In order to provide local and state governments, code administrative bodies and industry with a
modern, updated code, NAPHCC published the "National Standard Plumbing Code," in 1971,
following the format and sequence of the A40.8 to provide for maximum convenience of users.

With the June 1973 revision, the American Society of Plumbing Engineers joined this effort by
co-sponsoring the National Standard Plumbing Code. ASPE maintained its co-sponsorship status
until September, 1980. Upon ASPE's withdrawal of co-sponsorship, the Code Committee compo-
sition was changed to include not only members of the contracting and engineering communities
but also members of the inspection community. Contractors, engineers and inspectors now
comprise the National Standard Plumbing Code Committee.

The National Standard Plumbing Code Committee has worked closely with the plumbing industry
to maintain a document of minimum requirements for plumbing systems that reflect current
practices, materials, and techniques, consistent with public health and safety.

However, the written requirements of a Code can sometimes be interpreted differently by differ-
ent individuals. For this reason, the NSPC Committee developed the NSPC Illustrated, which
includes explanatory comments and illustrations to demonstrate the intent of the various Code
Sections.

The Committee also realizes that despite the countless hours of preparation and review, perfection
may not have been achieved in this document. For this reason, please send any questions, com-
ments, suggestions, or problems to the Code Secretary, Plumbing-Heating-Cooling Contractors -
National Association, P.O. Box 6808, Falls Church, VA 22046-1 148.

Comments on Code Text

The comments following the various Sections of the Code text are intended to explain the intent of
that Section of the Code. The comments themselves are not Code requirements but are intended
to supplement the Code and provide guidance toward its interpretation.

•

Figures and Figure Notes

The illustrations (figures) are intended to graphically demonstrate the intent or provide an example
of the referenced definition or Code Section. The illustrations are based only on the referenced
definition or Code Section and do not necessarily include all details of the complete installation,
such as pipe sizes, specific pipe fittings, required pipe supports, required cleanouts, and other
details that are not part of the definition or Code Section being illustrated. The illustrations must
not be used to justify work that does not comply with all requirements of the Code.

The illustrations are not intended to restrict installations to the arrangement shown. In many
cases, the illustrations show only one example or a typical example of an acceptable arrangement.
Any arrangement that meets the intent of the referenced Code Section is acceptable.

•

Introductory Note

The material presented in this Code does not have legal standing unless it is adopted by
reference, or by inclusion, in an act of state, county, or municipal government. Therefore,
administration of the provisions of this Code must be preceded by suitable legislation at the
level of government where it is desired to use this Code.

In some places in this Code, reference is made to "Authority Having Jurisdiction." The
identity of an Authority Having Jurisdiction will be established by the act which gives legal
standing to the Code provisions.

Meetings for purposes of review and revision are scheduled each year with proper public
notices.

Suggestions and requests for revisions can be made by any interested party and should
be submitted on the special forms provided by the Committee.

Personal appearance before the Committee for a hearing on any Code matter can be had
by interested parties after a request in writing.

In the course of revision, certain outdated sections have been deleted. In order to
maintain consistency and perpetuity of the numbering system, those deleted sections and
numbers have been removed from this printed text, or placed in reserve.

All changes from the previous edition of this Code are
marked by a vertical line in the margin.

2006 National Standard Plumbing Code Committee

J. Richard Wagner, PE, Chairman

The Poole & Kent Corporation

4530HollinsFerryRd

Baltimore, MD 212-27-4670

Phone:(410)247-2200

Fax: (410)247-2331

Dick_Wagner@emcorgroup.com

CharlieChalk

E-B-L Engineers, LLC
8005 Harford Rd
Baltimore,MD21234-5701
Phone:(410)668-8000
Fax: (410)668-8001
cchalk@eblengineers.com

William Chamberlin

Chamberlin Plbg. & Htg Company

P.O. Box 390

1274 Route 130 South

Windsor,NJ 08561

Phone:(609)448-1848

Fax: (609)448-8683

Michael J. Kastner

Kastner Plumbing & Heating
12630 Friendship Road
West Friendship, MD 21794
Phone:(301)725-5000
Fax: (410)442-7626
mjkjr@aoI.com

LeonLaFreniere

City of Manchester, Dept. of Buildings

One City Plaza

Manchester, NH 03101

Phone:(603)624-6475

Fax: (603)624-6324

llafreniere@ci.manchester.nh.us

Frank R. Maddalon

F. R. Maddalon Plumbing & Heating

1550 Sylvan Ave

Hamilton, N J 08610-4461

Phone:(609)587-8317

Fax: (609)587-9848

fmaddalon@aoI.com

Thomas C. Pitcherello

NJ Department of Community Affairs

Codes Assistance Unit

101 S. Broad Street, PO Box 802

Trenton, NJ 08625-0802

Phone:(609)984-7609

Fax: (609)984-7717

tpitchere!lo@dca. state. nj. us

Luis A. Rodriguez, C.P.D.

KSI Professional Engineers

P.O. Box 628

Farmingdale, N J 07727

Phone:(732)938.2666

Fax: (732)938.2661

E-mail: lrodriguez@ksi-pe.com

Ronald W.Stiegler

Phoenix Plumbers, Inc.
5320-J Enterprise St.
Eldersburg, MD 2 1 784-93 1 3
Phone:(410)781-3000
Fax: (410)781-6826
phoenixplumbers@erols.com

AlexTucciarone

Old Bridge Plumbinglnspector

58 Lear Ct

East Brunswick, NJ 08816-1853

Phone:(732)721-56002420

Fax: (732)607-7912

ajtuccia@oldbridge.com

Jerry Van Pelt, CIPE

Clive Samuels & Associates, Inc.
4000 Route 66
TintonFalls,NJ 07753
Phone: (732)643-9666
Fax: (732)643-9667
jvp@csa-ce.com

Dave Viola

Plumbing Manufacturers Institute
1340 Remington Rd., Suite A
Schaumburg, IL 60 1 73
Phone:(847)884-9764
Fax: (847)884-9775
dviola@pmihome.org

Robert Kordulak
NSPC Secretariat

The Arkord Company
206 1st Ave., #603
Belmar,NJ 07719-2006
Phone:(732)681-5400
Fax: (732)681-5047
bkord3565@optonline.net

Frank R. Maddalon
Executive Committee Liaison

F. R. Maddalon Plumbing & Heating

1550 Sylvan Ave

Hamilton,NJ 08610-4461

Phone:(609)587-8317

Fax: (609)587-9848

fmaddalon@aol.com

Julie A. Turner
StaffLiaison

Plumbing-Heating-Cooling Contrac-
tors-National Association
180 S.Washington St.,
Falls Church, VA 22046
(703)237-8100or(800)533-7694
Fax:(703)237-7442
e-mail: turner@naphcc.org
URL: http://www.phccweb.org

Contents

Title, Scope, Purpose, Exceptions i

Foreword iii

Introductory Note v

Committee Members vi

Administration 1

Basic Principles 9

Chapter 1 — Definitions 13

Chapter 2 — General Regulations 65

Chapter 3 — Materials 83

Chapter 4 — Joints and Connections 1 1 1

Chapter 5 — Traps, Cleanouts and Backwater Valves 135

Chapter 6 — Interceptors 151

Chapter 7 — PlumbingFixtures,FixtureFittings and Plumbing Appliances 161

Chapter 8 — Hangersand Supports 193

Chapter 9 — Indirect Waste Piping and Special Wastes 197

Chapter 10 — Water Supply and Distribution 209

Chapter 1 1 — Sanitary Drainage Systems 251

Chapter 12 — Vents and Venting 273

Chapter 13 — Storm WaterDrainage 31 1

Chapter 14 — Special Requirements for Health Care Facilities 325

Chapter 15 — Tests and Maintenance 331

Chapter 16 — Regulations GoverninglndividualSewageDisposal

Systems for Homes and Other Establishments Where

Public Sewage Systems AreNot Available 335

Chapter 17 — Potable Water Supply Systems 351

Chapter 18 — Mobile Home & Travel Trailer

Park Plumbing Standards 359

Appendix A — Sizing Storm Drainage Systems 367

AppendixB — Sizing the Building Water Supply System 375

Appendix C — Conversions: Customary Units to Metric 41 1

AppendixD — DeterminingtheMinimumNumberofRequired

Plumbing Fixtures 413

AppendixE — Special Design Plumbing Systems 419

AppendixF — Requirements ofthe Authority Having Jurisdiction 427

AppendixG — Gray water Recycling Systems 429

AppendixH — Installation of Medical Gas and Vacuum Piping Systems 433

Appendixl — Fixture Unit Value Curves for Water Closets 435

Appendix J — Sizing Grease Interceptors 439

AppendixK — Flow in Sloping Drains 441

AppendixL — An Acceptable Brazing Procedure for General Plumbing 445

Index — Alphabetical Index 453

•

Administration

ADM 1.1 TITLE

The regulations contained in the following chapters and sections shall be known as the "National Standard
Plumbing Code" and may be cited as such, and hereinafter referred to as "this Code".

ADM 1.2 SCOPE

The provisions of this Code shall apply to every installation, including the erection, installation, alteration, reloca-
tion, repair, replacement, addition to, use or maintenance of the plumbing system as defined within this Code.

ADM 1.3 PURPOSE

This Code establishes the minimum requirements and standards pertaining to the design, installation, use and
maintenance of the plumbing system as defined within this Code.

ADM 1.4 APPLICABILITY

1.4.1 Addition or Repair

Additions, alterations or repairs in compliance to this Code may be made to any existing plumbing system
without requiring the existing installation to comply with all the requirements of this Code. Additions, alterations or
repairs shall not cause an existing system to become unsafe, insanitary or overloaded.

1 .4.2 Existing Plumbing Installation

Plumbing systems that were lawfully installed prior to the adoption of this Code may continue their use, mainte-
nance or repairs, provided the maintenance or repair is in accordance with the original design, location, and no
hazard has been created to life, health or property by such plumbing system.

1.4.3 Existing Use

The lawful use of any plumbing installation, appliances, fixtures, fittings and appurtenances may have their use
continued, provided no hazards to life, health or property have been created by their continued use.

1.4.4 Maintenance and Repairs

The maintenance of all plumbing systems, materials, appurtenances, devices or safeguards, both existing and
new, shall be maintained in a safe and proper condition. The owner, or his designated agent, shall be responsible
for the maintenance of the plumbing system.

Minor repairs to or replacement of any existing systems are permitted, provided they are made in the same
manner and arrangement as the original installation and are approved.

1 .4.5 Change of Building Use

The plumbing systems of any building or structure that is proposed for a change in use or occupancy shall
comply to all the requirements of this Code for the new use or occupancy.

1.4.6 Moved Buildings or Structures

The plumbing system in any building or structure to be moved into this jurisdiction shall comply with the provi-
sions of this Code for new construction.

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1.4.7 Special Historic Buildings

The provisions of this Code relating to the additions, alterations, repair, replacement or restoration of those
structures designated as historic buildings shall not be mandatory when such work is deemed to be safe and in the
public interest of health, safety and welfare by the Authority Having Jurisdiction.

1.4.8 Appendices

The provisions in the appendices are intended to supplement the requirements of this Code and are considered
to be part of this Code when adopted by the Authority Having Jurisdiction

ADM 1.5 APPROVALS

1.5.1 Alternates

The provisions cited in this Code are not intended to prevent the use of any material or method of installation
when it is determined to meet the intent of this Code and approved by the Authority Having Jurisdiction

1.5.2 Authority Having Jurisdiction

The Authority Having Jurisdiction may approve any such alternate material or method of installation not ex-
pressly conforming to the requirements of this Code, provided it finds the proposed material or method of installa-
tion is at least the equivalent of that required in the Code or that the alternate material or method of installation
conforms to other nationally accepted plumbing standards. A record of such approval shall be kept and shall be
available to the public.

1.5.3 Tests Required

The Authority Having Jurisdiction shall require sufficient evidence to substantiate any claims made regarding the
equivalency of any proposed alternate material or method of installation. When the Authority Having Jurisdiction
determines that there is insufficient evidence to substantiate the claims, it may require tests to substantiate the
claims be made by an approved testing agency at the expense of the applicant.

1.5.4 Test Procedure

The Authority Having Jurisdiction shall require all tests be made in accordance with approved standards; but, in
the absence of such standards, the Authority Having Jurisdiction shall specify the test procedure.

1.5.5 Retesting

The Authority Having Jurisdiction may require any tests to be repeated if, at any time, there is reason to believe
thai any material or method of installation no longer conforms to the requirements on which the original approval
was based.

ADM 1.6 ORGANIZATION AND ENFORCEMENT

1.6.1 Authority Having Jurisdiction

The Authority Having Jurisdiction shall be the individual official, board, department or agency duly appointed by
the jurisdiction as having the authority to administer and enforce the provisions of this Code as adopted or
amended.

1.6.2 Deputies

In accordance with the procedures set forth by the jurisdictional authority, the Authority Having Jurisdiction may
appoint such assistants, deputies, inspectors or other designated employees to carry out the administration and
enforcement of this Code.

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1.6.3 RigHtofEntry

When inspections are required to enforce the provisions of this Code, or there is reasonable cause to believe
there exists in any building, structure or premises, any condition or violation of this Code causing the building,
structure or premises to be unsafe, insanitary, dangerous or hazardous, the Authority Having Jurisdiction or its
designated representative may enter such building, structure or premises at reasonable times to inspect or perform
the duties imposed by this Code. When the building, structure or premises are occupied, proper credentials shall be
presented to the occupant when entry is required. In the event the building, structure or premises is unoccupied,
and entry is required, a reasonable effort shall be made to locate the owner or his agent in charge of such building,
structure or premises. In the event the occupant or owner of such building, structure or premises refuses entry, the
Authority Having Jurisdiction shall have recourse to the remedies provided by law to gain entry.

1 .6.4 Stop Work Order

Upon notice from the Authority Having Jurisdiction, work being done on any building, structure or premises
contrary to the provisions of this Code, or in an unsafe and dangerous manner, shall be stopped immediately. The
stop work notice shall be in writing, served on the owner of the property, or his agent, or to the person doing such
work. It shall state the conditions under which the Authority Having Jurisdiction may grant authorization to
proceed with the work.

1 .6.5 Authority to Condemn

When the Authority Having Jurisdiction determines that any plumbing system or portion thereof that is regulated
by this Code has become insanitary or hazardous to life, health or property, it shall order in writing that such
plumbing system or portion thereof be repaired, replaced or removed so as to be in code compliance. The written
order shall fix a reasonable time limit for the work to be brought into code compliance, and no person shall use the
condemned plumbing system until such work is complete and approved by the Authority Having Jurisdiction.

1 .6.6 Authority to Abate

Any plumbing system, or portion thereof that is found to be insanitary or constitute a hazard to life, health or
property is hereby declared to be a nuisance. Where a nuisance exists, the Authority Having Jurisdiction shall
require the nuisance to be abated and shall seek such abatement in the manner prescribed by law.

1.6.7 Liability

The Authority Having Jurisdiction, or any individual duly appointed or authorized by the Authority Having
Jurisdiction to enforce this Code, acting in good faith and without malice, shall not thereby be rendered personally
liable for any damage that may occur to persons or property as a result of any act. or by reason of any act or
omission in the lawful discharge of his duties. Should a suit be brought against the Authority Having Jurisdiction or
duly appointed representative because of such act or omission, it shall be defended by legal counsel provided by
this jurisdiction until final termination of the proceedings.

1.6.8 Work Prior to Permit

Where work for which a permit is required by this Code is stalled prior to obtaining the prescribed permit, the
applicant shall pay a double fee. In the event of an emergency where it is absolutely necessary to perform the
plumbing work immediately, such as nights, weekends or holidays, said fee shall not be doubled if a permit is
secured at the earliest possible time after the emergency plumbing work has been performed.

ADM 1.7 VIOLATIONS AND PENALTIES

1.7.1 Violations

It shall be unlawful for any individual, partnership, firm or corporation to, or cause to, install, construct, erect,
alter, repair, improve, convert, move, use or maintain any plumbing system in violation of this Code.

20116 Naiiimol SinnrJnrd PUimhiim Code-llhisnatcd

1.7.2 Penalties
Any individual, partnership, firm or corporation who shall violate or fail to comply with any of the requirements

of this Code shall be deemed guilty of a , and if convicted, shall be punishable by a fine or imprisonment

or both as established by this jurisdiction. Each day during which a violation occurs or continues, shall constitute a
separate offense.

ADM 1.8 PERMITS

1.8.1 Permits Required

It shall be unlawful for any individual, partnership, firm or corporation to commence, or cause to commence, any
installation, alteration, repair, replacement, conversion or addition to any plumbing system, or part thereof, regulated
by this Code, except as permitted in Section 1 .8.2, without first obtaining a plumbing permit for each separate
building or structure, on forms prepared and provided by the Authority Having Jurisdiction.

1 .8.2 Permits Not Required for the Following

a. Permits shall not be required for the following work:

1 . The stoppage of leaks in drains, soil, waste or vent pipes. However, should the defect necessitate removal
and replacement with new material, it shall constitute new work and a permit shall be obtained and inspection
made as required in this Code.

2. The clearing of stoppages.

3. The repairing of leaks in valves or fixtures.

4. The removing and reinstallation of a water closet for a cleanout opening provided the reinstallation does not
require replacement or rearrangement of valves, pipes or new fixtures.

b. Exemptions from obtaining a permit required by this Code shall not be construed as to authorize any work to
be performed in violation of this Code.

ADM 1.9 PROCESS FOR OBTAINING PERMITS

1.9.1 Application

a. Applications for a permit shall be made in writing by the person, or his agent, proposing to do such work
covered by the permit. The applicant shall file such application in writing on a form prepared and provided by the
Authority Having Jurisdiction. Every such permit shall :

1 . Describe in detail the work to be done for which the permit was obtained.

2. Describe in detail the parcel of land on which the proposed work is to be done by legal description, sneet
address or other means to definitely locate the site or building where the work is to be performed.

3. List the type of occupancy or use.

4. Provide plans, drawings, diagrams, calculations or other data as required by Section 1 .9.2.

5. Be signed by the person or agent making application.

6. Provide any other information the Authority Having Jurisdiction may require.

1.9.2 Plans

Two or more sets of plans shall be submitted with each permit application. The plans shall contain all the
engineering calculations, drawings, diagrams and other data as required for approval. The Authority Having
Jurisdiction may also require that the plans, drawings, diagrams and calculations be designed by an engineer and/or
architect licensed by the state in which the work is to be performed.

Except that the Authority Having Jurisdiction may waive the submission of plans and other data, provided it is
determined that the nature of the work covered by the permit does not require plan review to obtain code compliance.

2006 National Standard Plumbing Code-Illustrated

1.9.3 Specifications

All specifications required to be on the plans shall be drawn to scale and sufficiently clear to indicate the nature,
location and extent of the proposed work so as to show how it will conform to the requirements of this Code.

1.9.4 Permit issuance

If, after reviewing the plans and specifications, the Authority Having Jurisdiction finds that they are complete
and conform to the requirements of this Code, it shall authorize a permit to be issued upon payment of all the fees
specified in Section 1.10.1.

1.9.5 Approved Plans

When the Authority Having Jurisdiction issues a permit and plans were required, it shall endorse, either in
writing or stamp the plans "APPROVED", and all work shall be done in accordance with the plans without
deviation.

1.9.6 Plans Retention

The Authority Having Jurisdiction shall retain one set of approved plans until final approval of the work con-
tained therein. One set of approved plans shall be returned to the applicant and this.seLof approved plans shall be
kept on the job site at all times until final approval of the work contained therein.

1.9.7 Permit Validity

The issuance of a permit by the Authority Having Jurisdiction is not and shall not be construed to be authoriza-
tion or approval of any violation of the requirements of this Code. Any presumption of a permit to be authorization
to violate or cancel any provisions of this Code shall be invalid. The issuance of a permit based on plans submitted
shall not prevent the Authority Having Jurisdiction from requiring the correction of any errors in the plans or
preventing the progress of the construction when it is in violation of any provision of this Code.

1.9.8 Permit Expiration

Every permit issued by the Authority Having Jurisdiction, in accordance with the provisions of this Code, shall
expire by limitation and become null and void when such work authorized by the permit has not commenced within
days from the date of issuance or if such work is suspended or abandoned for a period of days after com-
mencement of such work. In order for such work to recommence, a new permit shall be obtained and a fee of
percent of the original permit fee shall be charged, provided no changes have been made or will be made to the
original plans as submitted. The Authority Having Jurisdiction may grant an extension to any permit provided the
request is in writing by the permittee stating the reason or circumstances that prevented him from completing such
work as required by this Code.

1.9.9 Revocation or Suspension

At any time, the Authority Having Jurisdiction may suspend or revoke a permit issued in error or on the basis of
incorrect information submitted or in violation of any section of this Code. The suspension or revocation of such
permit shall be in written form by the Authority Having Jurisdiction stating the reason or purpose of such suspen-
sion or revocation.

ADM 1.10 PERMITS

1.10.1 Fees Schedule

The permit fees for all plumbing work shall be set forth by the Authority Having Jurisdiction of the jurisdiction
havinuauthoritv.

7006 National Standard Plumbing Cnde-lllustrated

1.10.2 Plan Review Fees

When plans are reviewed as a requirement prior to issuance of a permit, the fee shall be equal to percent

of the total permit fee as set forth in Section 1 . 10.1.

1.10.3 Plan Review Expiration

Permit application and plan review for which no permit is issued shall expire by limitation within days

following the date of application. All plan review fees shall be forfeited and the plans may be destroyed by the
Authority Having Jurisdiction or returned to the applicant.

1.10.4 Work Without a Permit

When any plumbing work is commenced without first obtaining a permit from the Authority Having Jurisdiction,
an investigation of such work shall be made before a permit may be issued. The investigation fee shall be collected
whether or not a permit is then or subsequently issued. Any investigation fee shall equal the amount of the permit
fee, if a permit were to be issued in accordance with this Code. If the investigation fee is collected, it shall not
exempt any person from compliance or penalties set forth in this Code.

1.10.5 Refunding of Fees

Any fee collected by the Authority Having Jurisdiction that was erroneously paid or collected may be refunded,

provided not more than percent of the fee payment shall be refunded when no work has been done. Any

request for the refunding of any fee shall be in writing by the applicant no later than days after the date of fee

payment.

ADM 1.11 INSPECTIONS

1.11.1 Required Inspections

All new plumbing systems, and parts of existing systems that require a permit shall be tested and inspected by
the Authority Having Jurisdiction prior to being covered or concealed. Where any such work has been covered or
concealed, the Authority Having Jurisdiction shall require such work exposed for inspection and testing. All
equipment, material and labor required for testing the plumbing system shall be furnished by the permittee. The
Authority Having Jurisdiction shall not be liable for any expense incurred by the removal or replacement of materi-
als required to permit inspection or testing. Such expense is the responsibility of the permittee. Upon completion of
the rough plumbing installation, prior to covering or concealing any such work, the Authority Having Jurisdiction
shall inspect the work and any such test, as prescribed hereinafter, to disclose any leaks or defects. After comple-
tion of the plumbing system and the plumbing fixtures are set and their traps filled with water, a final inspection
shall be conducted as required by this Code. Additional inspections may be required when alternate materials or
methods of installation are approved by the Authority Having Jurisdiction.

1.11.2 Exception:

For moved-in or relocated structures, minor installations and repairs, the Authority Having Jurisdiction may
make other such inspections or tests as necessary to assure that the work has been performed and is safe for use
in accordance with the intent of this Code.

1.11.3 Use of Existing Plumbing

The operation of any plumbing installation to replace existing systems or fixtures serving an occupied portion of
any building or structure shall not be considered by the requirements of this Code to prohibit such operation,
provided a request for inspection has been made to the Authority Having Jurisdiction within 48 hours of such work
and before any such work is covered or concealed.

200f> National Standard Plumbing Code-lllusiinted

•

1.11.4 System Testing

All new plumbing systems and parts of existing systems shall be tested and approved as required elsewhere in
this Code.

1.11.5 Requests for Inspection

The Authority Having Jurisdiction shall be notified by the person doing the work, authorized by the permit, that
such work is subjected to the required tests and is ready for inspection. The method of request, whether in writing
or by telephone, shall be established by the Authority Having Jurisdiction.

It shall be the duty of the permittee doing the work authorized by a permit to provide reasonable access and
means for accomplishing proper inspections.

1.11.6 Other Inspections

The Authority Having Jurisdiction may require other inspections, in addition to those required by this Code, of
any plumbing work in order to ascertain compliance with the requirements of this Code.

1.11.7 Reinspection Fees

a. The assessment of a reinspection fee may be required for any of the following:

1 . For any portion of work not completed for which inspection was requested.

2. For any required corrections that have not been completed and for which reinspection was requested.

3. For not having the approved plans on site and readily available to the inspector.

4. Failure to provide access for inspection on the date inspection was requested.

5. Deviation from the approved plans that would require reapproval of the Authority Having Jurisdiction.

6. Failure to provide correct address.

b. This provision is intended to control the practice of calling for inspections prior to having work ready for
inspection and not for the first time job rejection for not complying with the installation requirements.

c. Upon the assessment of a reinspection fee, the applicant shall pay the reinspection fee in accordance with
Section 1.10.1 and no additional inspections shall be performed until all fees have been paid.

ADM 1.12 FINAL CONNECTIONS

1.12.1 Energy or Fuel

it shall be unlawful for any person to make, or cause to make, any connection to any source of energy or fuel to
any plumbing system or equipment regulated by this Code prior to the approval of the Authority Having Jurisdic-
tion.

1.12.2 Water and Sewer

It shall be unlawful for any person to make, or cause to make, any connection to any water supply or sewer
system to any plumbing system or equipment regulated by this Code prior to the approval of the Authority Having
Jurisdiction.

1.12.3 Temporary Connection

By authorization of the Authority Having Jurisdiction, a temporary connection may be made to any plumbing
equipment to a source of energy or fuel for testing purposes only.

ADM 1.13 UNCONSTITUTIONALITY

Should any chapter, section, subsection, sentence, clause or phrase of this Code be held for any reason as
unconstitutional, such decision shall not affect the validity of the remaining chapters, sections, subsections, sen-
tences, clause or phrases of this Code.

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2006 National Standard Plumbing Code-Illustrated

B^isic|i||ncijj|esj

This Code is founded upon certain basic principles of environmental sanitation and safety through properly
designed, acceptably installed, and adequately maintained plumbing systems. Some of the details of plumbing
construction may vary but the basic sanitary and safety principles desirable and necessary to protect the health of
the people are the same everywhere.

The establishment of trade jurisdictional areas is not within the scope of this Code. This inclusion of material,
even though indicated as approved for purposes of this Code, does not infer unqualified endorsement as to its
selection or serviceability in any or every installation:

As interpretations may be required, and as unforeseen situations arise which are not specifically covered in this
Code, the twenty-two principles which follow shall be used to define the intent.

Principle No. 1— ALL OCCUPIED PREMISES SHALL HAVE POTABLEWATER

All premises intended for human habitation, occupancy, or use shall be provided with a supply of potable water.
Such a water supply shall not be connected with unsafe water sources, nor shall it be subject to the hazards of
backflow.

Principle No. 2— ADEQU ATE WATER REQUIRED

Plumbing fixtures, devices, and appurtenances shall be supplied with water in sufficient volume and at pressures
adequate to enable them to function properly and without undue noise under normal conditions of use.

Principle No.3-HOT WATER REQUIRED

Hot water shall be supplied to all plumbing fixtures which normally need or require hot water for their proper use
and function.

Principle No. 4— WATER CONSER VATION

Plumbing shall be designed and adjusted to use the minimum quantity of water consistent with proper performance
and cleaning.

Principle No. 5— SAFETY DEVICES
Devices for heating and storing water shall be so designed and installed as to guard against dangers from explosion
or overheating.

Principle No. 6— USE PUBLIC SEWER WHERE AVAILABLE

Every building with installed plumbing fixmres and intended for human habitation, occupancy, or use, and located
on premises where a public sewer is on or passes said premises within a reasonable distance, shall be connected to
the sewer.

Principle No. 7— REQUIRED PLUMBING FIXTURES

Each family dwelling unit shall have at least one water closet, one lavatory, one kitchen-type sink, and one bathtub
or shower to meet, the basic requirements of sanitation and personal hygiene.

All other structures for human habitation shall be equipped with sufficient sanitary facilities. Plumbing fixtures shall
be made of durable, smooth, non-absorbent and corrosion resistant materia] and shall be free from concealed
fouling surfaces.

2006 National Standard Plumbing Code-fliusn-aied

Principle No. 8— DRAINAGE SYSTEM

The drainage system shall be designed, constructed, and maintained to guard against fouling, deposit of solids and
clogging, and with adequate cleanouts so arranged that the pipes may be readily cleaned.

Principle No. 9— DURABLE MATERIALS AND GOOD WORKMANSHIP

The piping of the plumbing system shall be of durable material, free from defective workmanship and so designed
and constructed as to give satisfactory service for its reasonable expected life.

Principle No. 1 0— FIXTURE TRAPS

Each fixture directly connected to the drainage system shall be equipped with a liquid seal trap.

Principle No. 1 1— TRAP SEALS SHALL BE PROTECTED

The drainage system shall be designed to provide an adequate circulation of air in all pipes with no danger of
siphonage, aspiration, or forcing of trap seals under conditions of ordinary use.

Principle No. 12— EXHAUST FOUL AIR TO OUTSIDE

Each vent terminal shall extend to the outer air and be so installed as to minimize the possibilities of clogging and
the return of foul air to the building.

Principle No. 13— TEST THE PLUMBING SYSTEM

The plumbing system shall be subjected to such tests as will effectively disclose all leaks and defects in the work
or the material.

Principle No. 14— EXCLUDE CERTAIN SUBSTANCES FROM THE PLUMBING SYSTEM

No substance which will clog or accentuate clogging of pipes, produce explosive mixtures, destroy the pipes or
their joints, or interfere unduly with the sewage-disposal process shall be allowed to enter the building drainage
system.

Principle No. 15— PREVENT CONTAMINATION

Proper protection shall be provided to prevent contamination of food, water, sterile goods, and similar materials by
backflow of sewage. When necessary, the fixture, device, or appliance shall be connected indirectly with the
building drainage system.

Principle No. 16— LIGHT AND VENTILATION

No water closet or similar fixture shall be located in a room or compartment which is not properly lighted and
ventilated.

Principle No. 1 7— INDIVIDUAL SEWAGE DISPOSAL SYSTEMS

If water closets or other plumbing fixtures are installed in buildings where there is no sewer within a reasonable
distance, suitable provision shall be made for disposing of the sewage by some accepted method of sewage
treatment and disposal.

] 2006 Notional Standard Plumbin e C<Hle-llliist rated

Principle No. 18— PREVENT SEWER FLOODING

Where a plumbing drainage system is subject to backflow of sewage from the public sewer or private disposal
system, suitable provision shall be made to prevent its overflow in the building.

Principle No. 1 9— PROPER MAINTENANCE

Plumbing systems shall be maintained in a safe and serviceable condition from the standpoint of both mechanics
and health.

Principle No. 20— FIXTURES SHALL BE ACCESSIBLE

All plumbing fixtures shall be so installed with regard to spacing as to be accessible for their intended use and for
cleaning.

PrincipleNo.21— STRUCTURAL SAFETY

Plumbing shall be installed with due regard to preservation of the strength of structural members and=prevention of
damage to walls and other surfaces through fixture usage.

Principle No. 22— PROTECT GROUND AND SURFACE WATER

Sewage or other waste shall not be discharged into surface or sub-surface water unless it has first been subjected
to some acceptable form of treatment.

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Chapter 1

Definitions

1.1 GENERAL

For the purpose of this Code, the following terms shall have the meaning indicated in this chapter. No attempt is
made to define ordinary words that are used in accordance with their established dictionary meaning, except
where it is necessary to define their meaning as used in this Code to avoid misunderstanding.

1.2 DEFINITION OF TERMS

Accessible and Readily Accessible:

Accessible: access thereto without damaging building surfaces, but that first may require the removal of an
access panel, door or similar obstructions with the use of tools. See Figure 1.2.1

Readily accessible: access without requiring the use of toots for removing or moving any panel, door or
similar obstruction. See Figure 1.2.1

VALVE IS ACCESSIBLE IF LATCH
IS SCREWDRIVER-OPERATED

VALVE IS READILY ACCESSIBLE IF
LATCH IS HANDLE-OPERATED

Figure 1.2.1
AN EXAMPLE OF ACCESSIBLE AND READILY ACCESSIBLE

Acid Waste: See ""Special Wastes"

Adopting Agency (Sec also "Authority Having Jurisdiction") The agency, board or authority having the
duty and power to establish the plumbing code that will govern the installation of all plumbing work to be per-
Formed in the jurisdictions.

Air Break (drainage system): A piping arrangement in which a drain from a fixture, appliance, or device
discharges into a fixture, receptor, or interceptor at a point below the flood level rim and above the trap seal of the
receptor. See Figure 1.2.2 and Section 9.1.3

2006 National Standard Plumbing Code-Illustrated

Comment: Air breaks are permitted where backflow cannot occur due to back-siphonage.

FLOOD LEVEL RIM

INDIRECT WASTE PIPE
TERMINATING BELOW
FLOOD LEVEL RIM
OF RECEPTOR

STANDPIPE-

TOP OF TRAP SEAL

DISCHARGE HOSE

CLOTHES
WASHER

A. AIR BREAK IN FLOOR SINK

B. AIR BREAK IN CLOTHES
WASHER STANDPIPE

Figure 1.2.2
AIR BREAKS

Air Chamber: A pressure surge absorbing device operating through the compressibility of air.

Comment: The Code no longer mentions air chambers. Air chambers were usually field-fabricated and
were initially filled with air at atmospheric pressure. There was direct contact between the captive air
and water, which permitted the air to be absorbed into the water over a period of time. The Code now
calls for water hammer arrestors, which are pre-charged with compressed air or gas and have bellows or
pistons that separate the air or gas from the water. See Figure 1.23.

WATER HAMMER ARRESTOR

TO FIXTURE OR APPLIANCE
WITH QUICK CLOSING VALVE

BRANCH SHUTOFF VALVE

NOTES:

1 . For maximum effectiveness, the water hammer arrestor should be oriented so that the direction of

the shock wave caused by the quick-closing valve is into the arrestor. Refer to the manufacturer's
instructions.

2. The number of elbows upstream from the water hammer arrestor should be minimized. Each elbow

represents a point of shock and potential failure.

Figure 1.2.3
A WATER HAMMER ARRESTOR

2006 National Standard Plumbing Code- Illustrated

Air Gap (drainage system): The unobstructed vertical distance through the free atmosphere between the outlet
of the waste pipe and the flood level rim of the receptor into which it is discharging. See Figure 1.2.4

Comment: Air gaps are required where backflow can occur due to back-siphonage.

AIR GAP

INDIRECT WASTE RPE
-RECEPTOR

Figure 1.2.4
AN AIR GAP FOR INDIRECT WASTE PIPING

Air Gap (water distribution system): The unobstructed vertical distance through the free atmosphere between
the lowest opening from any pipe or faucet supplying water to a tank, plumbing fixture or other device and the
flood level rim of the receptor. See Figure 1.2.5

Comment #i; The minimum required air gap distance is based on the effective opening of the water
supply outlet. The air gap must be increased if the outlet is close to walls or other vertical surfaces* See
Section 10.5.2 and Table J 0.5.2.

Comment M2: If air is being drawn into the tub spout by a vacuum in the water supply piping, waste
water at the flood level rim of the fixture will tend to be lifted upward towards the spout opening by the
flow of air. The water will lift higher if the spout opening is close to a wall.

FLOOD LEVEL RIM
OF BATHTUB

TUB SPOUT

AIR GAP -i

Figure 1.2.5
AN AIR GAP FOR A POTABLE WATER OUTLET

2006 National Standard Plumbing Code-Illustrated

Anchors: See "Supports." See Chapter 8

Anti-scald Valve: See "Water Temperature Control Valve." See Section 10.15.6

Approved: Accepted or acceptable under an applicable standard stated or cited in this Code, or accepted as
suitable for the proposed use under procedures and powers of the Authority Having Jurisdiction as defined in
Section 3.12. See Sections 3.1.1, 3.1.2, 3.1.3, and 3.12

Area Drain: A receptor designed to collect surface or storm water from an open area. See Figures 1.2.6 and
13.1.6

TO AN APPROVED
POINT OF DISPOSAL

AREAWAY DRAIN
LESS THAN 100 S.F.
(Section 13.1.6)

Figure 1.2.6
AREA DRAINS JN WINDOW WELLS AND STAIR WELLS

Aspirator: A fitting or device supplied with water or other fluid under positive pressure that passes through an
integral orifice or "constriction" causing a vacuum. See Figure 1.2.7 and Section 14.13

Comment: Backflow prevention is required where the fluid supply is potable water.

A- INLET FLUID FLOW
B - INDUCED VACUUM
C - COMBINED OUTLET FLOW

Figure 1.2.7
AN ASPIRATOR FITTING

2006 National Standard Plumbing Code-Illustrated

Authority Having Jurisdiction (See also "Adopting Agency")

The individual official, board, department or agency established and authorized by a state, county, city or other
political subdivision created by law to administer and enforce the provisions of the plumbing code as adopted or
amended.

Automatic Flushing Device; A device that automatically flushes a fixture after each use without the need for
manual activation.

Auxiliary Floor Drain: A floor drain that does not receive the discharge from any indirect waste pipe. Auxiliary floor
drains have no DFU loading.

Backflow Connection: Any arrangement whereby backflow can occur.

Comment: See "Cross Connection ".

Backflow (drainage): A reversal of flow in the drainage system.

Backflow Preventer: A device or means to prevent backflow. See Figures 1.2.5, 1.2.8, 1.2.9, 1.2.23,
1.2.25, 1.2.26, 1.2.27, 1.2.48, 1.2.66, and 1.2.67.

Comment: Refer to the definitions of "backflow (water distribution) ", "back-pressure backflow",
"back-siphonage'% "critical level", "cross connection", "double check valve assembly", "reduced
pressure principle back-pressure backflow preventor", "vacuum breaker, atmospheric", "vacuum
breaker, pressure type", and "vacuum breaker, spill-proof".

POTABLE WATER
TO BUILDING

BUILDING VALVE

CURB VALVE BOX

&^mmmrw

CURB VALVE

Figure 1.2.8
BACKFLOW CAUSED BY BACK-PRESSURE

2006 National Standard Plumbing Code-Illustrated

J 7

NOTES:

1 . Back-pressure backflow is generally caused by water pressure producing equipment within a
building.

2. The hot water heating boiler operates at up to 30 psig and has a chemical shot feeder.

3. The pressure in the public water main can drop below 30 psig due to a shutdown for repair or heavy
demand for fire fighting operations.

4. The check valve and pressure reducing valve in the water makeup to the heating system are not
adequate to prevent back-pressure backflow.

5. The chemical feeder creates a potential "high hazard" that requires a reduced pressure zone
backflow preventor (RPZ). Otherwise, a double check valve assembly would be adequate.

6. An RPZ at Point "A" is required to protect the water distribution system within the building from
backflow of chemically treated boiler water.

7. An RPZ at Point "B" would "contain" the building and prevent it from backflowing any potential
contamination into the public water system.

Figure 1.2.8 (NOTES)
BACKFLOW CAUSED BY BACK-PRESSURE

FLOOD LEVEL RIM

VACUUM BREAKER NEEDED HERE -
LOCATED SIX (6 ) INCHES MINIMUM
ABOVE FLOOD LEVEL RIM

CHEMICAL SINK FAUCET WITHOUT
BACKFLOW PREVENTER

HW CW

POTABLE WATER SUBJECT
TO BACKFLOW

Figure 1.2.9
BACKFLOW CAUSED BY BACK-SIPHONAGE

Backflow (Water Distribution): The flow of water or other liquids, mixtures or substances from any source or
sources into the distribution pipes of a potable water system. Back-siphonage is one type of backflow. See
Figures 1.2.8 and 1.2.9

Backpressure Backflow: Backflow caused by a higher pressure in the non-potable system than in the potable
supply system. See Figure 1.2.8

Back-siphonage: Backflow caused by a greater negative pressure in the potable system than in the non-potable
supply system. See Figure 1.2.9

Backwater Valve: A device installed in a drain pipe to prevent backflow. See Figure 1.2.10

2006 National Standard Plumbing Code-Illustrated

•

Comment: Backwater valves are swing-type check valves that are installed in drainage piping to prevent
the reversal of flow in the piping and over/lows due to stoppages, flooding, or other abnormal condi-
tions. Refer to Section 5.5.] for where backwater valves are required.

ACCESS COVER

DIRECTION OF
DRAINAGE FLOW ■

yvtsvsssvgy

Figure 1.2.10
A BACKWATER VALVE

Baptistery: A tank or pool for baptizing by total immersion.

Bathroom Group: A group of fixtures in a dwelling unit bathroom consisting of one water closet, one or two
lavatories, and either one bathtub, one combination bath/shower or one shower stall. Other fixtures within the
bathing facility shall be counted separately when determining the water supply and drainage fixture unit loads.

Battery of Fixtures: Any group of two or more similar adjacent fixtures that discharge into a common horizontal
waste or soil branch. See Figure 1.2.11

Comment: Batteries of fixtures can be "battery vented" in groups of up to eight fixtures in accordance
with Section 12.13. Fixtures that are "battery vented" do not have to be the same type.

PLAN VIEW

Figure 1.2.11
A BATTERY OF FIXTURES

Bedpan Steamer: A fixture used for scalding bedpans or urinals by direct application of steam. See Section
14.10

Boiler Blow-off: An outlet on a boiler to permit emptying or discharge of sediment. See Figure 1.2.12

•

2006 National Standard Plumbing Code-Hiusirafed

CONTINUOUS SURFACE BLOWOFF

BOTTOM
BLOWOFF VALVES

ft-^i^w^wni^-^M

TO OUTDOORS

BOILER

BLOWOFF

TANK —

INLET-^ bzirzzr^r^L

VENT

„'t»,:.,,„-±,.^,.,:„.,„. 8 l,u i i im«i Tin: i i i — /-* ^ I * ■ i a t i . i ,■ ■ i if i ari.mi.iM— ■■•■ mi

SEDIMENT / y TOPi

DRAIN VALVE — ' [y * ^ £

POINT
SCHARGE

•

Figure 1.2.12
A BOILER BLOWOFF TANK

Boiler Blow-off Tank: A vessel designed to receive the discharge from a boiler blow-off outlet and to cool the
discharge to a temperature that permits its safe discharge to the drainage system. See Figure 1.2.12

Comment: Boiler blow-off must be cooled to 140°F or less before being discharged into the drainage
system. If potable water is supplied for cooling, the water source must be protected from backflow.
An air break can be provided at the discharge from the blow-off tank into the drainage system if the
makeup water supply to the boiler is protected against backflow. _^_^__

Branch: Any part of the piping system other than a riser, main or stack. See Figure 1.2.13

Comment: Branch piping can serve more than one fixture or appliance.

2006 National Standard Plumbing Code-Jlliisirnted

•

WASTE BRANCH
STACK

T J

WATER DISTRIBUTION
BRANCH

RISER

Figure 1.2.13
BRANCH PIPING

Branch, Fixture: See "Fixture Branch"

Branch, Horizontal: See "Horizontal Branch Drain"

Branch Interval: A distance along a soil or waste stack corresponding, in general, to a story height, but in no
case less than 8 feet within which the horizontal branches from one floor or story of a building are connected to
the stack. See Figure 1.2.14

Comment; Branch intervals are used to determine the potential drainage load on stacks for the purpose
of sizing the stacks.

•

SOIL OR WASTE STACK

Branch Vent: See "Vent, Branch"

8' MINIMUM

Figure 1.2.14
BRANCH INTERVALS

A-BANDB-DARE
BRANCH INTERVALS
B-C AND C-D ARE
NOT BRANCH
INTERVALS

1006 National Standard Pfitmbiiig Code-IUusiraled

Building: A structure having walls and a roof designed and used for the housing, shelter, enclosure, or support
of persons, animals, or property.

Building Classification: The arrangement adopted by the Authority Having Jurisdiction for the designation of
buildings in classes according to occupancy. See Table 7.21.1

Comment: The building classifications in Table 7.21.1 for the minimum number of required plumbing
fixtures include assembly, business, education, factory and industrial, institutional, mercantile, residen-
tial, storage, and utility/miscellaneous.

SOIL
STACK

10 FT MINIMUM
FROM STORM
TO SOIL
CONNECTIONS

COMBINED
BUILDING SEWER

Figure 1.2.15
A COMBINED BUILDING DRAINAGE SYSTEM

Building Drain: The lowest piping in a drainage system that receives the discharge from stacks and horizontal
fixture branches within a building that convey sewage, waste, or other drainage to a building sewer beginning
three (3) feet outside the building wall. Horizontal fixture branches are sized according to Table 1 1 .5. IB until
they connect to the building drain or a branch of the building drain that serves two or more horizontal fixture
branches. See Figure 1.2.16

Building Drain, Combined: A building drain which conveys both sewage and storm water or other drainage.
See Figure 1.2.15

2006 National Standard Plumbing Code-Illustrated

•

BUILDING DRAIN - SANITARY
(Z) BUILDING DRAIN - STORM

(3) BUILDING SEWER - SANITARY

(4) BUILDING SEWER - STORM

END OF BUILDING DRAINS

• PUBLIC SANITARY SEWER
PUBLIC STORM SEWER

Figure 1.2.16
SEPARATE SANITARY AND STORMWATER BUILDING DRAINS AND SEWERS

Building Drain, Sanitary: A building drain that conveys sewage only. See Figure 1.2.16

Building Drain, Storm: A building drain that conveys storm water or other drainage, but no sewage. See
Figure 1.2.16

Building Sewer: That part of the drainage system which extends from the end of the building drain and conveys
its discharge to a public sewer, private sewer, individual sewage-disposal system or other point of disposal. See
Figure 1.2.16

Building Sewer, Combined: A building sewer that conveys both sewage and storm water or other drainage.
See Figure 1.2.15

Building Sewer, Sanitary: A building sewer that conveys sewage only. See Figure 1.2.16

Building Sewer, Storm: A building sewer that conveys storm water or other drainage but no sewage. See
Figure 1.2.16

2006 National Standard Plumbing Code-Jllusirated

Building Subdrain: That portion of a drainage system that does not drain by gravity into the building sewer or
building drain. See Figure 1.2.17

DISCHARGE TO
GRAVITY DRAIN

SEWAGE SUMP PIT

WITH AUTOMATIC

SEWAGE PUMP

OR EJECTOR

VENT

BUILDING SUBDRAIN

Figure 1.2.17
A BUILDING SUBDRAIN

Building Trap: A device, fitting, or assembly of fittings, installed in the building drain to prevent circulation of air
between the drainage system of the building and the building sewer. See Figure 1.2.18

Comment: Building traps are currently installed only when required by the Authority Having Jurisdic-
tion.

FRESH AIR INTAKE
(SCREEN COVERED)

VENT NOT LESS THAN

1/2 THE SIZE

OF THE BUILDING

DRAIN

/ 1p

£- BUILDING DRAIN %4'-

TO BUILDING SEWER

BUILDING TRAP

Figure 1.2.18
A BUILDING TRAP

2006 National Standard Plumbing Code-Illustrated

•

Cesspool: A lined and covered excavation in the ground that receives the discharge of domestic sewage or other
organic wastes from a drainage system, so designed as to retain the organic matter and solids, but permitting the
liquids to seep through the bottom and sides.

Comment: Chapter 16 does not permit cesspools or cesspits, into which untreated sewage is discharged
and allowed to seep into the ground. Chapter 16 requires septic tanks to retain the sewage until digested
and absorption trenches or seepage pits for underground disposal of the effluent.

Chemical Waste: See "Special Wastes" See Sections 2.10 and 9,4
Circuit Vent: See "Vent, Circuit" See Figure 12.13.1

Clear Water Waste: Effluent in which impurity levels are less than concentrations considered harmful by the
Authority Having Jurisdiction, such as cooling water and condensate drainage from refrigeration and air condition-
ing equipment, cooled condensate from steam heating systems, and residual water from ice making processes.

Comment: Refer to Section 9.1.8 for whether a clear water waste requires an air gap or an air break at
its discharge into the drainage system.

Clinical Sink: A sink designed primarily to receive wastes from bedpans, having a flushing rim, intergral trap
with a visible trap seal, and having the same flushing and cleansing characteristics as a water closet. See Sec-
tion 14.8

Code: These regulations, or any emergency rule or regulation that the Authority Having Jurisdiction may lawfully
adopt.

Combination Fixture: A fixture combining one sink and laundry tray, or a two- or three-compartment sink or
laundry tray in one unit. See Figure 1.2.19

Comment: Combination fixtures with waste outlets not more than 30 inches apart can have one trap

THREE COMPARTMENT SINK

1
1

1 1
J L

ZffZ

1 1
J L

i
i

SINK AND LAUNDRY TRAY

1 ll.

t r

'-&

Figure 1.2.19
COMBINATION FIXTURES

Combination Thermostatic/Pressure Balancing Valve: See "Thermostatic/Pressure Balancing Valve,
Combined"

Combination Waste and Vent System: A designed system of waste piping embodying the horizontal wet
■*■■ venting of one or more sinks or floor drains by means of a common waste and vent pipe adequately sized to
provide free movement of air above the flow line of the drain. See Figure 1.2.20 and Section 12.17

•

2006 National Standard Plumbing Code-Illustrated

Comment #/; Combination waste and vent piping systems are permitted where conditions preclude the
installation of a conventionally vented system. Such systems are frequently used in exhibition halls and
other spaces where long clear spans are required without partitions or pipe chases.

Comment #2: Only floor drains, floor receptors, sinks, lavatories, and standpipes can be discharged into
a combination waste and vent piping system.

•

TO CONNECTION WITH
CONVENTIONALLY SIZED
AND VENTED DRAINAGE
PIPING

OVERSIZED COMBINATION WASTE & VENT
PIPING PER TABLE 12.17.4

Figure 1.2.20
COMBINATION WASTE AND VENT PIPING

Combined Building Drain: See "Building Drain, Combined"

Combined Building Sewer: See "Building Sewer, Combined"

Common Vent: See "Vent, Common"

Conductor: A pipe within a building that conveys stormwater from a roof to its connection to a building storm
drain or other point of disposal. See Figure 1.2.21

Comment: A vertical stormwater drain pipe on the exterior of a building is a leader.

ROOF DRAIN

CONDUCTOR — — ■

TO AN APPROVED
POINT OF DISCHARGE

Figure 1.2.21
A STORMWATER CONDUCTOR

2006 National Standard Plumbing Code-Illustrated

•

Contamination: The impairment of the quality of the potable water that creates an actual hazard to the public health
through poisoning or through the spread of disease by sewage, industrial fluids or waste. (See the definition of
"pollution").

Continuous Vent: See "Vent, Continuous"

Continuous Waste: A drain from two or more fixtures connected to a single trap. See Figure 1.2.22

Comment: Continuous waste piping can connect up to three adjacent sinks or lavatories to a single trap
if the fixture outlets are no more than SO" apart. See Section 5.1.

END OUTLET

TRAP
CENTER OUTLET

Figure 1.2.22
CONTINUOUS WASTE PIPING

Critical Level: The marking on a backflow prevention device or vacuum breaker established by the manufac-
turer, and usually stamped on the device by the manufacturer, that determines the minimum elevation above the
flood level rim of the fixture or receptor served at which the device must be installed. When a backflow preven-
tion device does not bear a critical level marking, the bottom of the vacuum breaker, combination valve, or the
bottom of any approved device constitutes the critical level. See Figure 1.2.23 and Sections 10.5.5.D, c, and e

VACUUM BREAKER

REQUIRED DISTANCE
(See Section 10.5.5)

OVERFLOW OR
FLOOD LEVEL

FIXTURE,

APPLIANCE, OR

RECEPTOR

Figure 1.2.23
THE CRITICAL LEVEL (C-L) OF A VACUUM BREAKER

2006 National Standard Plumbing Code-Ilhtsirated

Cross Connection: Any connection or arrangement between two otherwise separate piping systems, one of that
contains potable water and the other either water of questionable safety, steam, gas, or chemical, whereby there
may be a flow from one system to the other, the direction of flow depending on the pressure differential between
the two systems (See "Backflow and Back-Siphonage). See Figures 1.2.8 and 1.2.9

Comment: The backflow of contamination into a potable water system through a cross connection can
occur by back-siphonage caused by the water system or back-pressure from the source of contamination.

Day Care Center: A facility for the care and/or education of children ranging from 2-1/2 years of age to 5 years
of age.

Day Nursery: A facility for the care of children less than 2-1/2 years of age.

Dead End, Potable Water: A branch line terminating at a developed length of two (2) feet or more from
an active potable water line by means of a plug or cap. See Figure 1.2.24

Comment: An extension of 2 feet or more to make a cleanout accessible is not considered to be a dead
end.

VENT^-

DEAD END

GREATER THAN 2 FEET

DRAIN t-

DEAD END

GREATER THAN 2 FEET

Figure 1.2.24
DEAD ENDS IN DRAIN AND VENT PIPING

Dead End, Soil, Waste, or Vent: A branch leading from a soil, waste or vent pipe, building drain, or
building sewer line and terminating at a developed length of two (2) feet or more by means of a plug, cap,
or other closed fitting.

Developed Length: The length of a pipe line measured along the center line of the pipe and fittings.

Diameter: See "Size of Pipe & Tubing"

Domestic Sewage: The water-borne wastes derived from ordinary living processes.

2006 National Standard Plumbing Code~IUusirated

POTABLE
WATER —
SUPPLY

OPTIONAL
WYE STRAINER

TEST PORTS

RESILIENT SEATED
GATE VALVES

TO BACKPRESSURE OR BACKSIPHONAGE
NON-HEALTH HAZARD APPLICATIONS

Figure 1.2.25
A DOUBLE CHECK VALVE ASSEMBLY

Double Check Valve Assembly: A backflow prevention device consisting of two independently acting check
valves, internally force loaded to a normally closed position between two tightly closing shut-off valves, and with
means of testing for tightness. See Figure 1.2.25

Double Offset: See "Offset, Double"

Downspout: See "Leader"

Drain: Any pipe that carries waste or water-borne wastes in a building drainage system.

Drainage Pipe: See "Drainage System"

Drainage, Sump : A liquid and air-tight tank that receives sewage and/or liquid waste, located below the
elevation of a gravity drainage system, that is emptied by pumping.

Drainage System: All the piping within public or private premises that conveys sewage, rain water, or other
liquid wastes to a point of disposal. It does not include the mains of a public sewer system or private or public
sewage-treatment facilities.

Drainage System, Building Gravity: A drainage system that drains by gravity into the building sewer. See
Figure 1.2.16

Drainage System, Sub-building: See "Building Subdrain" See Figure 1.2.17

Dry Vent: See "Vent, Dry"

Dry Well: See "Leaching Well"

Dual Vent: See "Vent, Common"

Dwelling Unit, Multiple: A room, or group of rooms, forming a single habitable unit with facilities that are used,
or intended to be used, for living, sleeping, cooking and eating; and whose sewer connections and water supply,
within its own premise, are shared with one or more other dwelling units. Multiple dwelling units include guest
rooms in hotels and motels.

2006 National Standard Plumbing Cocle-llhtstiawd

Comment: Apartments, condominiums, and guest rooms in hotels and motels are examples of multiple
dwelling units.

Dwelling Unit, Single: A room, or group of rooms, forming a single habitable unit with facilities that are used, or
intended to be used, for living, sleeping, cooking and eating; and whose sewer connections and water supply are,
within its own premise, separate from and completely independent of any other dwelling.

DWV: An acronym for "drain-waste-vent" referring to the combined sanitary drainage and venting systems.
This term is equivalent to "soil-waste-vent" (SWV).

Effective Opening: The minimum cross-sectional area at the point of water supply discharge, measured or
expressed in terms of (1) diameter of a circle, or (2) if the opening is not circular, the diameter of a circle of
equivalent cross-sectional area. See Figures 1.2.26 and 1.2.27

Comment: The required air gap distance for a water supply outlet is based on its effective opening. The
air gap must be increased if the outlet is near a wall or other vertical surface. Refer to Table J 0.5.2 for
minimum air gaps for plumbing fixtures.

AIR GAP NOT LESS
THAN 2 X "D"

EFFECTIVE OPENING (DIAMETER "D")

Figure 1.2.26
THE EFFECTIVE OPENING OF A POTABLE WATER OUTLET

POTABLE

WATER — V* —

SUPPLY

FLOAT
VALVE

PUMP DISCHARGE TO A
NON-POTABLE WATER SYSTEM

~pX r~ AIR GAP

^ J_{See Table 10.5.2)

D- EFFECTIVE OPENING OF WATER SUPPLY OUTLET

PUMP

yvv ' M ' v; vi ' *. vv* ^ v^ vv<; ^ ' w; vv . ^^ ' v^ -T'r^'TT^ xT 'T' V ' ^X 'r':' ';'

Figure 1.2.27
AN AIR GAP BETWEEN POTABLE AND NON-POTABLE WATER SYSTEMS

Equivalent Length: The length of straight pipe of a specific diameter that would produce the same frictional
resistances as a particular fitting or line comprised of pipe and fittings. See Tables B.9.7A and B.9.7B

Existing Plumbing System: An existing plumbing system, or any part thereof, installed prior to the effective
date of this Code.

Existing Work: A plumbing system, or any part thereof, installed prior to the effective date of this Code.

2006 National Standard Plumbing Code- Illustrated

•

Family; One or more individuals living together and sharing the same facilities.
Fixture: See "Plumbing Fixture"

Fixture Branch, Drainage: A drain serving one or more fixtures that discharges into another drain. See
Figure 1.2.28

Comment: See Table 11. 5. LB for the maximum number of drainage fixture units (DFU) permitted on
each size of horizontal fixture branch.

VENT

W KT

J"T

h*K

FIXTURE BRANCH

FIXTURE DRAINS

Figure 1.2.28
A FIXTURE DRAIN AND FIXTURE BRANCH

Fixture Branch, Supply: A branch of the water distribution system supplying one fixture. See Figure 1.2.29

Comment: See Table 10.14. 2.A for minimum supply fixture branch sizes for various fixtures.

FIXTURE SUPPLY TUBE

/ x - FIXTURE STOP VALVE
/ I , I

FIXTURE SUPPLY
BRANCH

Figure 1.2.29
A FIXTURE SUPPLY BRANCH AND FIXTURE SUPPLY TUBE

Fixture Drain: The drain from the trap of a fixture to the junction of that drain with any other drain pipe.

2006 National Standard Plumbing Code-fllustrated

Fixture Unit (Drainage -DFU): An index number that represents the load of a fixture on the drainage system
so that the load of various fixtures in various applications can be combined. The value is based on the volume or
volume rate of drainage discharge from the fixture, the time duration of that discharge, and the average time
between successive uses of the fixture. One DFU was originally equated to a drainage flow rate of one cubic foot
per minute or 7.5 gallons per minute through the fixture outlet. See Table 11.4.1

Fixture Unit (Water Supply - WSFU): An index number that represents the load of a fixture on the water
supply system so that the load of various fixtures in various applications can be combined. The value is based on
the volume rate of supply for the fixture, the time duration of a single supply operation, and the average time
between successive uses of the fixture. Water supply fixture units were originally based on a comparison to a
flushometer valve water closet, which was arbitrarily assigned a value of 10 WSFU. See Table 10.14.2A. Also
Tables B.5.2 and B.5.3.

Flexible Water Connector: A connector under continuous pressure in an accessible location that connects a supply
fitting, faucet, dishwasher, cloths washer, water heater, water treatment unit, or other fixture or equipment to a stop
valve or its water supply branch pipe

Flood Level: See "Flood Level Rim'

Flood Level Rim: The edge of the receptor or fixture over which water flows if the fixture is flooded. See
Figure 1.2.30

Comment: Air gaps are measured from above the flood level rim of receptors and fixtures.

FLOOD LEVEL RIM

WATER
CLOSET

URINAL FLOOR SINK

DRAIN

LAVATORY

BATHTUB

Figure 1.2.30
THE FLOOD LEVEL RIM OF FIXTURES

Flooded: The condition that results when the liquid in a receptor or fixture rises to the flood level rim.

Flow Pressure: The pressure in the water supply pipe near the faucet or water outlet while the faucet or water
outlet is fully open and flowing. See Figure 1.2.31

Comment; The minimum required flowing water pressure for most fixtures and appliances is ISpsig.
Blowout water closets and blowout urinals require 25 psig minimum. Some one-piece water closets
require 30 psig minimum and 1/2" supply tubes.

2006 National Standard Plumbing Code-Illustrated

•FLOW PRESSURE

•NO FLOW PRESSURE

i n \

Figure 1.2.31
THE FLOW PRESSURE OF THE WATER SUPPLY TO AN OUTLET

Flush Pipes and Fittings: The pipe and fittings that connect a flusbometer valve or elevated flush tank to a water
closet, urinal, or bed pan washer.

Flushing Type Floor Drain: A floor drain that is equipped with an integral water supply connection, enabling
flushing of the drain receptor and trap. See Figure 1.2.32

Comment: The water supply to flushing floor drains must be protected from backflow.

DRAIN

TRAP FLUSHING CONNECTION SUPPLIED FROM
AN APPROPIATE BACKFLOW PREVENTION DEVICE

Figure 1.2.32
A FLUSHING TYPE FLOOR DRAIN

Flush Valve: A device located at the bottom of a tank for flushing water closets and similar fixtures. See
Figure 1.2.33

•

2006 National Standard Plumbing Code-Illustrated

OVERFLOW
TUBE -~.

LOWER LIFT WIRE

TANK SEAL BALL

- FLUSH VALVE ASSEMBLY

)

Figure 1.233
A FLUSH VALVE IIS A WATER CLOSET FLUSH TANK

Flushometer Tank: A water closet flush tank that uses an air accumulator vessel to discharge a predetermined
quantity of water into the closet bowl for flushing purposes. See Figure 1.2.34

Comment: Flushometertanks are pressure-assisted flush tanks that store water for flushing water closets
at the inlet water supply pressure, as opposed to gravity tanks. The discharge rate from flushometer
tanks is approximately 35 gallons per minute.

PRESSURE TANK

Figure 1.2.34
A PRESSURE-ASSISTED WATER CLOSET WITH A FLUSHOMETER TANK

Flushometer Valve: A device that discharges a predetermined quantity of water to fixtures for flushing and is
closed by direct water pressure or other means. See Figure 1.2.35

Comment: Flushometer valves are typically used on public water closets and public urinals. They can
be manually operated or electronically operated.

2006 National Standard Plumbing Cocle-IHustraied

•

Figure 1.2.35
A FLUSHOMETER VALVE

Force Main: A main that delivers waste water under pressure from a sewage ejector or pump to its destina-
tion.

Full-way valve: Full-way valves include gate valves, full port ball valves, and other valves that are identified by their
manufacturer as full port or full bore.

Grade: The fall (slope) of a line of pipe in reference to a horizontal plane. See Figure 1.2.36.

Comment: See Tables J 1,5.1 A and ll.SJBfor sizing building drains, building servers, and horizontal
fixture branches. See Table 13.6.2 for stormwater drains.

SLOPING GRAVITY DRAIN

$&mm? —

FLOW

FALL

Figure 1.2.36
GRADE ON A SLOPING GRAVITY DRAIN

Grease Interceptor: A plumbing appurtenance that is installed in the sanitary drainage system to intercept oily and
greasy wastes from wastewater discharges, typically in commercial kitchens and food processing plants. Such
equipment has the ability to intercept commonly occurring free-floating fats and oils.

Grease Recovery Device (GRD): A plumbing appurtenance that is installed in the sanitary drainage system to
intercept and remove free-floating fats, oils, and grease from wastewater discharges, typically in commercial kitchens
and food processing plants. Such equipment operates on a time or event- controlled basis and has the ability to remove
the entire range of commonly occurring free-floating fats, oils, and grease automatically without intervention from the
user except for maintenance. The removed material is essentially water-free, which allows for recycling of the
removed product.

Grease Trap: See "Interceptor"

2006 National Standard Plumbing Code-fllustrated

Grinder Pump: A pump for sewage that shreds or grinds the solids in the sewage that it pumps.

Groundwater: Subsurface water occupying the zone of saturation, (a) confined ground water -a body of ground
water overlaid by material sufficiently impervious to sever free hydraulic connection with overlying ground water, (b)
free ground water - ground water in the zone of saturation extending down to the first impervious barrier.

Half-Bath: A room that contains one water closet and one lavatory within a dwelling unit.

Hangers: See "Supports" See Chapter 8

Health Hazard In backflow prevention, an actual or potential threat of contamination of the potable water supply
to the plumbing system of a physical or toxic nature that would be a danger to health. Health hazards include any
contamination that could cause death, illness, or spread of disease.

Horizontal Branch Drain: A drain pipe extending laterally from a soil stack, waste stack or building drain with
or without vertical sections or branches, that receives the waste discharged from one or more fixture drains and
conducts the waste to a soil stack, waste stack, or building-drain.

Horizontal Pipe: Any pipe or fitting that makes an angle of less than 45° with the horizontal. See Figure

1.2.37

Comment: The sizing of offsets in drainage stacks varies depending on whether the offset is horizontal or
vertical. See Section 1 1.6.

HORIZONTAL PIPE
(LESS THAN 45°)

HORIZONTAL

HORIZONTAL PLANE

Figure 1.2.37
THE DEFINITION OF "HORIZONTAL PIPE"

Hot Water: Potable water that is heated to a required temperature for its intended use.

House Drain: See "Building Drain"

House Sewer: See "Building Sewer"

House Trap: See "Building Trap"

Indirect Connection (Waste): The introduction of waste into the drainage system by means of an air gap or air

break.

Indirect Waste Pipe: A waste pipe that does not connect directly with the drainage system, but which dis-
charges into the drainage system through an air break or air gap into a trap, fixture, receptor or interceptor. See
Figure 1.2.38

36 2006 Naiiuual Standard Plumbing Code-Illuslraled

INDIRECT WASTE PIPE

AIR BREAK OR AIR GAP
(Section 9.1)

T^-

-WALK IN REFRIGERATOR

SINK

AIR BREAK OR
AIR GAP
(Section9.1) -

INDIRECT WASTE PIPE

INDIRECT WASTE
RECEPTORS

Figure 1.2.38
INDIRECT WASTE PIPES

Individual Vent; See "Vent, Individual"

Industrial Wastes: Liquid or liquid-borne wastes resulting from the processes employed in industrial and
commercial establishments.

Comment: Industrial wastes must not be discharged into public sewers if they will damage the sewer or
interfere with the operation of the sewage treatment plant.

Insanitary: Contrary to sanitary principles — injurious to health.

Installed: Altered, changed or a new installation ,

Interceptor: A device designed and installed so as to separate and retain deleterious, hazardous, or undesirable
matter from normal wastes while permitting normal sewage or liquid wastes to discharge into the drainage system
by gravity. See Figure 1.2.39

Comment: Interceptors include grease interceptors, oil/water separators, sand interceptors, solids
interceptors, and neutralizing or dilution tanks.

r STATIC WATER LINE

FLOW

INVERT

FLOW

INVERT

Figure 1.2.39
AN INTERCEPTOR

2006 National Standard Plumbing Code-Hlitsirateit

Invert: The lowest portion of the inside of a horizontal pipe. See Figure 1.2.40

Comment: Invert elevations are used to design and install drainage piping at the required grade or
slope.

INVERT

HORIZONTAL PIPE

Figure 1.2.40
THE INVERT OF A DRAIN PIPE

Leaching Well or Pit: A pit or receptor having porous walls that permit the liquid contents to seep into the ground.
See Figure 1.2.41

Comment: Leeching wells or pits are used to disperse the effluent from septic tanks into the ground for
secondary treatment They may supplement or be used in lieu of absorption trenches. Leaching wells or
pits can only be used where there is very deep soil of good permeability and considerable depth to
groundwater.

20O6 National Standard Plumbing Cixie-lllusiraiecl

FROM SEPTIC TANK — fr, fff

CORBEL 1/3 WIDTH
OF BLOCK _ _

MORTAR IN JOINTS ~ ~~ ~~ "~^>'

BLOCKS MAY BE LAYERED
WITHOUT MORTAR IN JOINTS

PLACE BLOCK CELLS IN
HORIZONTAL POSITION
EVERY OTHER COURSE — — '

FILL 3" ANNULAR SPACE
WITH CLEAN COURSE
GRAVEL OR CRUSED STONE ■

QOOOQD Q OC

0DDDDOXOX3C

PIT WALL

-22

ii ii i e ■■■■■■ i 1 1 ii m

m^mmsm.

fr v^ r mm

o £

X £L

o s

uj O

x u

SECTION

SMALL AMOUNT OF MORTAR
BETWEEN BLOCKS ADDS
RIGIDITY

BUTT BLOCKS FOR
RADIAL ARCH SUPPORT

Figure 1.2.41
A LEACHING OR SEEPAGE WELL OR PIT

Leader: An exterior vertical drainage pipe for conveying storm water from roof or gutter drains. See Figure
1.2.42

Comment: A stormwater drainpipe on the interior of a building is a conductor.

^£S^

■ LEADER

SPLASH BLOCK OR OTHER
APPROVED POINT OF DISPOSAL

Figure 1.2.42
A STORMWATER LEADER

2006 National Standard Plumbing Code-Ulustialed

Load Factor: The percentage of the total connected fixture unit flow which is likely to occur at any point in the
drainage system.

Local Ventilating Pipe: A pipe on the fixture side of the trap through which vapor or foul air is removed from a
fixture. See Figure 1.2.43

Comment: Local vent piping may be required for clinical sinks, bedpan washers, and sterilizers. Local
vents for sterilizers must not be connected to local vents for clinical sinks and bedpan washers. Refer to
Section 14.9 for clinical sinks and bedpan washers. Refer to Section 14.10 for sterilizers.

TO OUTDOORS

r//SJJSSS/;?JJ/*JJ-ji >TJ>J>/,

LOCAL VENT — —

STERILIZER

o.o I

Figure 1.2.43
A STERILIZER LOCAL VENTILATING PIPE

Loop Vent: See "Vent, Loop"

Low Hazard: See "Hazard, Low"

Macerating Toilet System: A system that collects drainage from a single water closet, lavatory and/or bathtub
located in the same room. It consists of a receiving container, a grinder pump, and associated level controls. The system
pumps shredded or macerated sewage up to a point of discharge

Main: The principal pipe artery to which branches may be connected.

Main Sewer: See "Public Sewer"

May: The word "may" is a permissive term.

Medical Gas System: The complete system used to convey medical gases for direct application from centra)
supply systems (bulk tanks, manifolds and medical air compressors) through piping networks with pressure and
operating controls, alarm warning systems, etc., and extending to station outlet valves at use points.

Comment: Medical gas systems must comply with NFPA 99 - Standard for Health Care Facilities or
NFPA 99C-Gas and Vacuum Systems. NFPA 99 is the parent document for NFPA 99C. NFPA 99
addresses all safety aspects of health care facilities, whereas NFPA 99C limits itself to the medical gas
and vacuum portions of NFPA 99.

Medical Vacuum Systems: A system consisting of central-vacuum-producing equipment with pressure and
operating controls, shut-off valves, alarm warning systems, gauges and a network of piping extending lo and
terminating with suitable station inlets to locations where suction may be required.

2006 National Standard Plumbing Cwie-lllusinned

Comment: Refer to the comment under Medical Gas System.

Multiple Dwelling: A building containing two or more dwelling units.

Non-Health Hazard: In backflow prevention, an actual or potential threat to the physical properties or potability
of the water supply to the plumbing system, but which would not constitute a health or system hazard.

Non-potable Water: Water not safe for drinking or for personal or culinary use.

Nominal Size: A standard expression in inches and fractions thereof to denote equal. Existing in name only and
not in actuality.

Nuisance: Public nuisance at common law or in equity jurisprudence; whatever is dangerous to human life or
detrimental to health; whatever building, structure, or premises is not sufficiently ventilated, sewered, drained,
cleaned, or lighted in reference to its intended or actual use; and whatever renders the air, human food, drink or
water supply unwholesome.

Offset: A combination of elbows or bends that brings one section of the pipe out of line but into a line parallel
with the other section. See Figure 1.2.44 - Parts A and B for single offsets

Comment: Offsets can occur in vertical and horizontal piping. Offsets can consist of90~degree, 45-
degree, or other angle fittings. Single offsets have one change of alignment.

t$r\

sf_-44

Figure 1.2.44
OFFSETS IN PIPING

Offset, Double: Two offsets installed in succession or series in a continuous pipe. See Figure 1.2.44 - Parts
E and F

Comment: Double offsets have two offsets, both away from the original alignment of the pipe.

Offset, Return: A double offset installed so as to return the pipe to its original alignment. See Figure 1.2.44
Parts C and D

Comment: Return offsets have two offsets, both in different directions. The second offset does not
necessarily bring the pipeline back into exact alignment with the first. The alignment of the piping on
both sides of the offset is not necessarily exactly the same laterally.

Oil Interceptor: See "Interceptor"

Person: A natural person, his heirs, executors, administrators or assigns; including a firm, partnership or corpora-
tion, its or their successors or assigns. Singular includes plural; male includes female.

2006 National Standard Plumbing Code-IUuslrutcd

Pitch: See "Grade"

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

The practice, materials, and fixtures within or adjacent to any building structure or conveyance, used in the
installation, maintenance, extension, alteration and removal of any piping, plumbing fixtures, plumbing appliances,
and plumbing appurtenances in connection with any of the following:

a.. Sanitary drainage system and its related vent system,

b. Storm water drainage facilities,

c. Public or private potable water supply systems,

d. The initial connection to a potable water supply upstream of any required backflow prevention
devices and the final connection that discharges indirectly into a public or private disposal system,

e. Medical gas and medical vacuum systems,

f. Indirect waste piping including refrigeration and air conditioning drainage,

g. Liquid waste or sewage, and water supply, of any premises to their connection with an approved
water supply system or to an acceptable disposal facility.

NOTE: The following are excluded from the definition:

1 . All piping, equipment or material used exclusively for environmental control.

2. Piping used for the incorporation of liquids or gases into any product or process for use in the
manufacturing or storage of any product, including product development.

3. Piping used for the installation, alteration, repair or removal of automatic sprinkler systems
installed for fire protection only.

4. The related appurtenances or standpipes connected to automatic sprinkler systems or overhead or
underground fire lines beginning at a point where water is used exclusively for fire protection.

5. Piping used for lawn sprinkler systems downstream from backflow prevention devices.

Plumbing Appliance: Any one of a special class of plumbing fixture that is intended to perform a special
plumbing function. Its operation and/or control may be dependent upon one or more energized components, such
as motors, controls, heating elements, or pressure or temperature-sensing elements. Such fixtures may operate
automatically through one or more of the following actions: a time cycle, a temperature range, a pressure range, a
measured volume or weight; or the fixture may be manually adjusted or controlled by the user or operator.

Comment: Plumbing appliances include clothes washers, dishwashers, food-waste-disposal and grinder
units, water heaters, water softeners, and similar devices. Refer to Table 3.1.3 - Part VII for listed
appliances.

Plumbing Appurtenance: A manufactured device, a prefabricated assembly, or an on-the-job assembly of
component parts, that is an adjunct to the basic piping system and plumbing fixtures. An appurtenance demands
no additional water supply, nor does it add any discharge load to a fixture or to the drainage system. It is pre-
sumed that an appurtenance performs some useful function in the operation, maintenance, servicing, economy, or
safety of the plumbing system.

Comment: Some examples of plumbing appurtenances are water filters, backflow prevention devices,
backwater valves, interceptors, separators, and neutralizing or dilution tanks. Refer to Table 3.1.3 - Part
VIII for listed appurtenances. Plumbing appurtenances do not change the load on the water supply or
drainage system.

42 2006 National Standard Plumbing Code-Illustrated

•

Plumbing Fixture: A receptacle or device connected to the water distribution system of the premises, and
demands a supply of water there from; or discharges used water, liquid-borne waste materials, or sewage either
directly or indirectly to the drainage system of the premises; or which requires both a water supply connection and
a discharge to the drainage system of the premises. Plumbing appliances as a special class of fixture are further
defined.

Comment: Plumbing fixtures include water closets, urinals, bidets, lavatories, bathtubs, whirlpool baths,
showers, sinks, floor drains, and receptors. Refer to Table 3.1.3 - Part Vfor listed plumbing fixtures.

•

Plumbing Inspector: See "Authority Having Jurisdiction"

Plumbing System: Includes the water supply and distribution pipes, plumbing fixtures and traps; soil, waste and
vent pipes; sanitary and storm drains and building sewers; including their respective connections, devices and
appurtenances to an approved point of disposal.

Pollution "Potable Water": An impairment of the quality of the potable water to a degree that does not create
a hazard to the public health but that does adversely and unreasonably affect the aesthetic qualities-of such
potable water for domestic use. (See the definition of "contamination").

Pool: See "Swimming Pool"

Potable Water: Water free from impurities present in amounts sufficient to cause disease or harmful physiologi-
cal effects and conforming in its bacteriological and chemical quality to the requirements of the Public Health
Service Drinking Water Standards or the regulations of the public health authority having jurisdiction.

Powder Room: See "Half-Bath"

Pressure Assisted Water Closet: See "Water Closet, Pressure Assisted"

Pressure Balancing Valve: A mixing valve which senses incoming hot and cold water pressures and compen-
sates for fluctuations in either to stabilize its outlet temperature.

Comment: Pressure balancing control valves for individual bathing facilities must comply with ANSI/
ASSE1016,TypeP.

Private Sewage Disposal System: A system for disposal of domestic sewage by means of a septic tank or
mechanical treatment, designed for use apart from a public sewer to serve a single establishment or building. See
Chapter 16

Private Sewer: A sewer not directly controlled by public authority.

Comment: A private sewer connects a building to a private sewage disposal system.

Private Use, Public Use:

Private Use - Plumbing facilities for the private and restricted use of one or more individuals in dwelling units
(including hotel and motel guest rooms), and other plumbing facilities that are not intended for public use. Refer to
the definition of "Public Use"-

2006 National Standard Plumbing Cude-lllusrraied

Public Use - Plumbing facilities intended for the unrestricted use of more than one individual (including employ-
ees) in assembly occupancies, business occupancies, public buildings, transportation facilities, schools and other
educational facilities, office buildings, restaurants, bars, other food service facilities, mercantile facilities, manufac-
turing facilities, military facilities, and other plumbing installations that are not intended for private use. Refer to
the definition of "Private Use".

Private Water Supply: A supply, other than an approved public water supply, which serves one or more build-
ings. See Figure 1.2.46 and Chapter 17

WELL SEAL
(Section 17.9.1)

PITLESS ADAPTER

WELL CASING

PRESSURE TANK
(Section 17.2.4.A)

TO POINT OF USE

-TANK DRAIN
(Section 17.5.5)

SUBMERSIBLE PUMP
(Section 17.6)

-WELL

Figure 1.2.46
A TYPICAL PRIVATE WATER SUPPLY SYSTEM

•

Public Sewer: A common sewer directly controlled by public authority.

Comment: This Code does not cover public sewers. The design and construction of public sewers is
regulated by the sewage authority, a public works department, or other Authority Having Jurisdiction.

Public Toilet Room: A toilet room intended to serve the transient public, such as in, but not limited to the
following examples: service stations, train stations, airports, restaurants, and convention halls.

Public Water Main: A water supply pipe for public use controlled by public authority.

Comment: This Code does not cover public water mains. The design and construction of public water
mains is regulated by the water purveyor, a public works department, or other Authority Having Juris-
diction.

•

Pump Assisted Water Closet: See "Water Closet, Pump Assisted"

Receptor: A fixture or device which receives the discharge from indirect waste pipes. See Figure 1.2.47

Comment: Receptors include floor drains, standpipes, and certain sinks.

2006 National Standard Plumbing Code-Illustrated

•

OPEN TOP OR

FULL / PARTIAL TOP GRATE

FLOOR SINK

Figure 1.2.47
AN INDIRECT WASTE RECEPTOR

Reduced Pressure Backflow Preventer Assembly: See Reduced Pressure Zone Backflow Preventer
Assembly

Reduced Pressure Principle Assembly: A reduced pressure zone backflow preventer assembly.

Reduced Pressure Zone Backflow Preventer Assembly: A backflow prevention device consisting of two
independently acting check valves, internally force loaded to a normally closed position and separated by an
intermediate chamber (or zone), in which there is an automatic relief means of venting to atmosphere internally
loaded to a normally open position, and with means for testing for tightness of the checks and opening of the relief
means. See Figure 1.2.48

Comment: Reduced pressure principle backflow preven tor assemblies provide the highest level of
protection against backpressure backflow. The shutoff valves on these assemblies are resiliently seated
to assure tight close-off for testing. Provisions must be made to drain any discharge from the relief vent
outlet, which may occur due to normal variations in system pressure.

SHUT-OFF
VALVE

OPTIONAL
STRAINER

RELIEF
VALVE \|

ASSEMBLY

REDUCED

PRESSURE

VALVE

VENT OUTLET

Figure 1.2.48
A REDUCED PRESSURE BACKFLOW PREVENTER ASSEMBLY

•

Relief Vent: See "Vent, Relief
Return Offset: See "Offset, Return"
Revent Pipe: See "Vent, Individual"

2006 National Standard Plumbing Code-Illusirawd

Rim: An unobstructed open edge of a fixture. See Figure 1.2.30

Comment: The flood level rim of a fixture or appliance is the level from which it wilt overflow if its drain
outlet is closed or blocked.

Riser: A water supply pipe that extends vertically one full story or more to convey water to branches or to a
group of fixtures. See Figure 1.2.49

Comment: The term "riser" refers to vertical water supply piping serving one or more fixtures in
buildings having one or more story heights.

WATER SUPPLY
RISER-

TO FIXTURES

RISER SHUT OFF VALVE

Figure 1.2.49
A WATER SUPPLY RISER

•

Roof Drain: A drain installed to receive water collecting on the surface of a roof and to discharge it into a leader
or a conductor. See Figure 1.2,50

Comment: Roof drains include flat deck drains and scupper drains.

Figure 1.2.50
A CpENERAL. PURPOSE ROUr DRAJJN

Roughing-in: The installation of all parts of the plumbing system that can be completed prior to the installation of
fixtures. This includes drainage, water supply, and vent piping, and the necessary fixture supports, or any fixtures
that are built into the structure.

2006 National Standard Plumbing Code-Illustrated

•

Safe Waste: See "Indirect Waste Pipe"

Sand Filter: A treatment device or structure, constructed above or below the surface of the ground, for removing
solid or colloidal material of a type that cannot be removed by sedimentation, from septic tank effluent. See
Figure 1.2.51 and Section 16.12

Comment #1: Sand filters provide additional treatment of septic tank effluent. They are used where the
soil depth is shallow and cannot provide sufficient secondary treatment of the effluent

Comment #2: Sand interceptors (or sand traps) are associated with oil/water separators in Chapter 6.

REMOVABLE COVER

SETTLING BEDS

Figure 1.2.51
A SAND FILTER FOR SEPTIC TANK EFFLUENT

Sand Interceptor: See "Interceptor" See Section 6.4

Comment: Sand interceptors (or sand traps) are associated with oil/water separators in Chapter 6. Sand
Jitters are associated with the effluent from septic tanks in Chapter 16.

Sand Trap: See "Interceptor'

Comment: The term "sand trap" is used interchangeably with "sand interceptor.'

Sanitary Sewer: A sewer that carries sewage and excludes storm, surface and ground water.

SDR: An abbreviation for "standard dimensional ratio" that relates to a specific ratio of the average specified
outside diameter to the minimum wall thickness for outside controlled diameter plastic pipe.

Seepage Well or Pit: See "Leaching Well"

Septic Tank: A watertight receptacle that receives the discharge of a building sanitary drainage system or part
thereof; and that is designed and constructed so as to separate solids from the liquid, digest organic matter through
a period of detention, and allow the liquids to discharge into the soil outside of the tank through a system of open
joint or perforated piping, or a seepage pit. See Figure 1.2.52 and Section 16.6

Comment: Figure 1.2.52 shows baffles at the inlet and outlet connections with two access covers.
Figure 16.6.6 shows 6" long drop pipes on the inlet and outlet connections with cleanouts and a single
access cover. Both arrangements perform the same functions and either arrangement is acceptable.

2006 National Standard Plumbing Code -Illustrated

ACCESS COVER

INLET X~"»-
FROM ^~ - "

OUTLET

ABSORPTION

MrvcM

Figure 1.2.52
A TYPICAL SEPTIC TANK

Service Sink: A sink or receptor intended for custodial use that is capable of being used to fill and empty a
janitor's bucket. Included are mop basins, laundry sinks, utility sinks, and similar fixtures. (See Table 7.21. 1)

Sewage: Liquid containing human waste (including fecal matter) and/or animal, vegetable, or chemical waste
matter in suspension or solution.

Sewage Ejector, Pneumatic Type: A unit that uses compressed air to discharge and lift sewage to a gravity
sewage system. See Sections 11.7 and 12.14.3

Sewage Pump or Pump-Type Ejector: A non-clog or grinder-type sewage pump or ejector. Sewage pumps
and pump-type ejectors are either the submersible or vertical type. See Figure 1.2.54 and Section 11.7

Comment: Figure 1.2.54 shows a pedestal-type sewage pump. Sewage pumps can also be submersible
pumps or dry pit centrifugal pumps.

LEVEL CONTROL SWITCH
AND HIGH LEVEL ALARM

FROM BUILDING
SUB- DRAIN — •«-£

VENT
SECTION 11. 7.4

AIRTIGHT COVER

WATER-TIGHT
DRAINAGE SUMP

Figure 1.2.54
A PEDESTAL TYPE SEWAGE PUMP

2006 National Standard Plumbing Code- Illustrated

Shall: "Shall" is a mandatory term.

Shock Arrestor (mechanical device): A device used to absorb the pressure surge (water hammer) that occurs
when water flow is suddenly stopped. See Figure 10.14.7 and Section 10.14.7 for Water Hammer Arres-
tors. Also Figure 1.2.3

Comment: Water hammer arrestors are either the bellows or piston type and are pre-charged with
compressed air or gas. The Code no longer mentions air chambers, which are subject to losing their
initial captive air charge through absorption into the system water.

Short Term: A period of time not more than 30 minutes.

Side Vent: See "Vent, Side"

Sink, Commercial: A sink other than for a domestic application. Commercial sinks include, but are not limited to:

1 . pot sinks

2. scullery sinks

3. sinks used in photographic or other processes

4. laboratory sinks

Size of Pipe and Tubing: The nominal inside diameter in inches as indicated in the material standards in Table
3.1 .3. If outside diameter is used, the size will be followed by "o.d.".

Size of Pipe and Tubing, Incremental: Where relative size requirements are mentioned, the following schedule
of sizes is recognized, even if all sizes may not be available commercially: 1/4,3/8, 1/2, 3/4, 1,1-1/4, 1-1/2,2,2-1/2,
3,3-1/2,4,4-1/2,5,6,7,8,10,12,15,18,21,24.

Slip Joint: A connection in drainage piping consisting of a compression nut and compression washer that permits
drainage tubing to be inserted into the joint and secured by tightening the compression nut. Slip joints are typically
used in trap connections for lavatories, sinks, and bathtubs. They permit the trap to be removed for cleaning or
replacement, and to provide access to the drainage piping.

Slope: See "Grade"

Soil Pipe or Soil Stack: Pipes that convey sewage containing fecal matter to the building drain or building sewer.

Special Wastes: Wastes that require special treatment before entry into the normal plumbing system. See
Figures 1.2.55 and 9.4.1. Also Section 9.4

Comment: Figure 1.2.55 shows a neutralizing tank for acid waste using limestone or marble chips.
Figure 9.4. J shows an automatic neutralizing tank that could treat either acid or caustic wastes, depend-
ing on the neutralizing solution used.

2006 National Standard Plumbing Code-Illustrated 49

ACCESS COVER

SIDE OR TOP VENT

INLET-

OUTLET-

FILL LEVEL OF
LIMESTONE OR
MARBLE CHIPS
2"x3"

Figure 1.2.55
A NEUTRALIZING OR DILUTION TANK FOR SPECIAL WASTE

Special Waste Pipe: Pipes which convey special wastes. See Section 3.11 for acceptable piping materials

Stack: A general term for any vertical line including offsets of soil, waste, vent or inside conductor piping. This
does not include vertical fixture and vent branches that do not extend through the roof or that pass through not
more than two stories before being reconnected to the vent stack or stack vent. See Figure 1.2.56, Section
11.5.2, and Table 11.5.1B

Comment: Stacks include soil stacks, waste slacks, vent stacks, and stack vents. See separate definitions.

r + "

VENT STACK

SECOND STORY

STACK VENT

DRINKING I

FOUNTAIN I *

FIRST STORY ■

BASEMENT

W.C W.C W.C.

— o o o-

LAV | LAV

-SOIL STACK

WC. W.C

— o o-

LAV | LAV | LAV |

Figure 1.2.56
A STACK VENT

2006 National Standard PlnmbhiQ Code-lUiistniied

Stack Group: A group of fixtures located adjacent to the stack so that by means of proper fittings, vents may be
reduced to a minimum. See Section 12.11 for stack venting groups of fixtures

Stack Vent: The extension of a soil or waste stack above the highest horizontal drain connected to the stack.
See Figure 1.2.56

Stack Venting: A method of venting a fixture or fixtures through the soil or waste stack. See Figure 1.2.57
and Section 12.11

VENT

T
i
i
I

LAVATORY

TUB/SHOWER

WATER
CLOSET

Figure 1.2.57
STACK VENTING

Standpipe (indirect waste receptor): A vertical drain pipe that has an open top inlet that provides an air break
or air gap for indirect waste discharge.

Storm Drain: See "Drain, Storm"

Storm Sewer: A sewer used for conveying rainwater, surface water, condensate, cooling water, or similar liquid
wastes.

Subsoil Drain: A drain that collects subsurface or seepage water and conveys it to a place of disposal. See
Figure 1.2.59 and Section 13.1.5 for foundation drains

Comment: Refer to Table 3.8 for acceptable materials for subsoil drains.

2006 National Standard Plumbing Code-Illustrated

SUMP WITH
SUMP PUMP TO
COLLECT AND
DISCHARGE CLEAR
WATER WASTES
(Section 13.1.5)

Figure 1.2.59
SUBSOIL DRAIN PIPING

Suction Line: The inlet pipe to a pump on which a negative pressure may exist under design conditions.

Sump: A tank or pit that receives only liquid wastes, located below the elevation of a gravity discharge, that is
emptied by pumping.

Sump, Drainage (sewage): A liquid and air-tight tank that receives sewage and/or liquid waste, located below
the elevation of a gravity drainage system, that is emptied by pumping. See Figure 1.2.54

Sump Pump: A permanently installed mechanical device for removing clear water or liquid waste from a sump.
See Figure 1.2.60

LIFTING HANDLE

SEALED MOTOR

SCREEN

j t==a-— SWITCH

MOTOR-^JOOOOCJ

^- •• *

pEDESTAL p — ,—

DRIVE SHAFT——'' « rS

DISCHARGE

FLOAT

A. SUBMERISBLE TYPE

^ INLET SCREEN
PUMP BODY- ^JJi^W - DISCHARGE

B. PEDESTAL TYPE

Figure 1.2.60
DIFFERENT TYPES OF SUMP PUMPS

2006 National Standard Plumbing Code-llhtsiraied

Supports; Devices for supporting and securing pipe, fixtures and equipment. See Chapter 8

Swimming Pool: Any structure, basin, chamber or tank containing a body of water for swimming, diving, or
recreational bathing. See Section 9.1.11

Tempered Water: A mixture of hot and cold water to reach a desired temperature for its intended use.

Therroostatic/Pressure Balancing Valve, Combination: A mixing valve that senses outlet temperature and
incoming hot and cold water pressure and compenstates for fluctuations in incoming hot and cold water tempera-
tures and/or pressures to stabilize its outlet temperatures.

Comment: Combination thermostatic/pressure balancing control valves are used for individual bathing
facilities and must comply with ASSE 1016, Type PT.

Thermostatic (Temperature Control) Valve: A mixing valve that senses outlet temperature and compensates
for fluctuations in incoming hot or cold water temperatures.

Comment: Thermostatic control valves used for individual bathing facilities must comply with ASSE
1016, Type T. Thermostatic control valves for other poini-of-use applications should comply with the
appropriate standard.

Toilet Facility: A room or combination of interconnected spaces in other than a dwelling that contains one or
more water closets and associated lavatories, with signage to identify its intended use.

Trap: A fitting or device that provides a liquid seal to prevent the emission of sewer gasses without materially
affecting the flow of sewage or waste water through it. See Figure 1.2.62 and Sections 5.1, 5.2, and 5.3

-INLET

CROWN WEIR OF TRAP

OUTLET

TRAP
SEAL

-TRAP DIP

Figure 1.2.62
ELEMENTS OF A FIXTURE TRAP

Trap Arm: That portion of a fixture drain between a trap and its vent. See Figure 1.2.63 and Section 12.8.1

Comment: Refer to Table 12.8. 1 for the maximum allowable length of trap arms to avoid trap siphonage.

2000 National Standard Plumbing Corfe-llhtstraied

INSIDE WALL
OF PIPE

VENT

TOP OF VENT OPENING

WASTE

NOTES:

1 . The top of the opening to the vent at the end of the trap arm must not be below the weir of the trap.

Figure 1.2.63
THE LENGTH OF A TRAP ARM
Trap Primer: A device or system of piping to maintain a water seal in a trap. See Figures 1.2.64 and 1.2.65.
Also Section 7.16.2

SUPPLY -

TO FIXTURE

INTEGRAL AIR GAP

TO TRAP

Figure L2.64
A FLOW-ACTIVATED TRAP PRIMER

POTABLE WATER LINE

TRAP PRIMER

TRAP SEAL

TRAP

Figure 1.2.65
CONNECTION OF A TRAP PRIMER TO A TRAP

2006 National Standard Plumbing Code- Illustrated

Trap Seal: The maximum vertical depth of liquid that a trap will retain, measured between the crown weir and
the top of the dip of the trap. See Figure 1.2.62 and Section 5.3.2

Vacuum: Any pressure less than that exerted by the atmosphere.

Vacuum Assisted Water Closet: See "Water Closet, Vacuum Assisted"

Vacuum Breaker: See "Backflow Preventer"

Vacuum Breaker, Atmospheric Type: A vacuum breaker that is not designed to be subject to static line
pressure. See Figure 1.2.66

A. THREADED TYPE ATMOSPHERIC

B. HOSE TYPE ATMOSPHERIC

Figure 1.2.66
TYPES OF ATMOSPHERIC VACUUM BREAKERS

Vacuum Breaker, Pressure Type: A vacuum breaker designed to operate under conditions of static line
pressure. See Figure 1.2.67

!"*> I°l

PRESSURE
VACUUM I
BREAKER \
150 PSI MAX '
140* F MAX

Figure 1.2.67
A PRESSURE TYPE VACUUM BREAKER

Vacuum Breaker, Spill-resistant (SVB): A pressure-type vacuum breaker specifically designed to avoid
spillage during operation, consisting of one check valve force-loaded closed and an air inlet vent valve force-loaded
open to atmosphere, positioned downstream of the check valve, and located between and including two tightly
closing shut-off valves and a means for testing.

2006 National Standard Plumbing Code-llfttstraieil

Comment. SVB vacuum breakers are spill-resistant, not spill-proof.

Vacuum Relief Valve: A device to prevent vacuum in a pressure vessel. See Figure 1.2.69 and Section
10.16.7

Comment: Vacuum relief valves are required on storage-type hot water heaters that are located above
the fixtures that they serve to prevent the tank from being siphoned dry and damaged by dry-firing.

{

Figure 1.2.69
A VACUUM RELIEF VALVE

Vent, Branch: A vent connecting one or more individual vents with a vent stack or stack vent. See Figure
1.2.70

■ BRANCH VENT ■

' URINAL T

W.C.

w.c.

I LAV

LAV

Figure 1.2-70

A BRANCH VENT

Vent, Circuit: A venf that connects to a horizontal drainage branch and vents from two to eight traps or trapped
fixtures connected in a battery. See Figure 1.2.71

Comment: Circuit vents connect to vent stacks. Loop vents connect to stack vents.

2006 National Standard Plumbing Codc-lihistruted

•

RELIEF
VENT -

-SOIL STACK

VENT STACK

w.c.

CIRCUIT VENT
W.C.

g— S_g--g

-L

Figure 1.2.71

A CIRCUIT VENT

Vent, Common: A vent connected at the common connection of two fixture drains and serving as a vent for
both fixtures. See Figure 1.2.72

LAV

q— — p

- COMMON VENT
LAV

Figure 1.2.72
A COMMON VENT
Vent, Continuous: A vertical vent that is a continuation of the drain to which it connects. See Figure 1.2.73

CONT1NOUS VENT

LAV

FIXTURE DRAIN
i

Figure 1.2.73
A CONTINUOUS VENT

Vent, Dry: A vent that does not receive the discharge of any sewage or waste.

Vent, Individual: A pipe installed to vent a single fixture dram. See Figure 1.2.74

2006 National Standard Plumbing Code-Illustrated

LAV

■£]

"tj

INDIVIDUAL VENT

TRAP ARM ■

FIXTURE DRAIN
i

Figure 1.2.74
AN INDIVIDUAL VENT

Vent, Loop: A circuit vent that loops back to connect with a stack vent instead of a vent stack. See Figure

1.2.75

Comment: Loop vents connect to stack vents. Circuit vents connect to vent stacks.

w.c.

LOOP VENT

W.C.

S_g

Figure 1.2.75
A LOOP VENT

■STACK VENT

Vent, Relief: An auxiliary vent that permits additional circulation of air in or between a drainage and vent
system. See Figures 12.3.1, 12.3.2, 12.3.3-A, 12.3.3-B, 12.13.1, 12.15.1, and 12.16.2

Comment; Relief vents are required at points in some vertical drainage stacks, at horizontal offsets in
some drainage stacks, at the base of some stacks, and at some battery vented branch connections to
stacks. Refer to Chapter 12.

Vent, Side: A vent connecting to a drain pipe through a fitting at an angle not greater than 45° to the vertical.
See Figure 1.2.76

2006 National Standard Plumbing Code-Illustrated

'V'

VERTICAL DRAIN •

'"V

NOT LESS THAN 45°
ABOVE HORIZONTAL

'V-

HORIZONTAL DRAIN

Figure 1.2.76
SIDE VENTS

Vent, Sterilizer; A separate pipe or stack, indirectly connected to the-building drainage system at the lower
terminal, that receives the vapors from non-pressure sterilizers, or the exhaust vapors from pressure sterilizers, and
conducts the vapors directly to the outer air. Sometimes called vapor, steam, atmosphere or exhaust vent. See
Section 14.11

Vent, Wet: A vent that receives the discharge of wastes from fixtures other than water closets or kitchen sinks.
See Figure 1.2.77. Refer to Section 12.10 for other arrangements of wet venting.

T
I

t LAVATORY

WATER
CLOSET

■WET VENT

Figure 1.2.77
A WET VENT

Vent, Yoke: A pipe connecting upward from a soil or waste stack to a vent stack for the purpose of equalizing
the pressures in the stacks. See Figure 1.2.78

•

Comment: A yoke vent is vertical. No portion of a yoke vent can be horizontal.

2006 National Standard Plumbing Code-ll 'fust rated

T
k

VENT STACK
(Section 12.3.1)

1) S

•

■YOKE VENT

—SOIL OR WASTE STACK

Figure 1.2.78
A YOKE VENT

Vent Pipe: Part of the vent system.

Vent Stack: A vertical vent-pipe that extends through one or more stories and that is intended to provide circula-
tion of air to and from the drainage system. See Figures 1.2.71 and 12.3.1

Vent System: A pipe, or pipes, installed to provide a flow of air to or from a drainage system or to provide a
circulation of air within such system to protect trap seals from siphonage and back pressure. See Figure 1.2.79

VERTICAL

VERTICAL PIPE (45 c OR MORE)

HORIZONTAL PLANE

VERTICAL

Figure 1.2.79
THE DEFINITION OF "VERTICAL PIPE"

2006 National Standard Plumbing Code-Illustrated

•

Vertical Pipe: Any pipe or Fitting that makes an angle of 45° or more with the horizontal. See Figure 1.2.79

Wall Hung Water Closet: A water closet installed in such a way that no part of it touches the floor. See
Figure 1.2.80

Figure 1.2.80
A WALL HUNG WATER CLOSET

Waste: Any remaining liquid, or liquid-bome material or residue intended to be discharged to the drainage system
after any activity or process, but not including any such materials that contain animal or human fecal matter.

Waste Pipe: A pipe that conveys only waste.

Waste Stack, Pipe or Piping: Pipes that convey the discharge from fixtures (other than water closets), appli-
ances, areas, or appurtenances, that do not contain fecal matter.

Water Closet, Pressure Assisted: A low consumption water closet with an air accumulator vessel in the tank
that stores water and air under pressure, using the water supply pressure. When flushed, the air produces a high
velocity jet of water and air that forces the contents out of the bowl.

Water Closet, Pump Assisted: A low consumption water closet with a fractional horsepower pump in the tank
that produces a high velocity jet in the trap way that assists the flushing action.

Water Closet, Vacuum Assisted: A low consumption water closet that uses the falling water level in the tank
to induce a vacuum near the outlet of the trap way that assists the flushing action.

Water Distribution Piping: Piping within the building or on the premises that conveys water from the water-
service pipe to the point of use. See Figure 1.2.81

2006 National Standard Plumbing Code-Hhtstratecl

BATHTUB

FROM SOURCE

COLD

HOT

Figure 1.2,81
WATER DISTRIBUTION PIPING

Water Lifts: See "Sewage Ejector"

Water Main: A water supply pipe for public use. See "Public Water Main"

Water Outiet: A discharge opening through which water is supplied to a fixture, into the atmosphere (except
into an open tank ,ha. is pa'* oftne water s^ply system), <o a boL or heann* sy s,e m , ,o any devices or eq^

ment requiring water to operate but that are not part of the plumbing system.

2006 National Standard Plumbing Code-Illustrated

Water Riser Pipe: See "Riser"

Water Service Pipe: The pipe from the water main, or other source of potable water supply, to the water
distribution system of the building served. See Figure 1.2.82 and Section 10.6

CURB BOX OR
WATER METER
AT PROPERTY LINE

T£

CORPORATION
COCK-

APPROVED

SHUT-OFF

VALVE (Section 10.12.1)

-WATER DISTRIBUTION PIPING

BUILDING

VALVE AND DRAIN

(Section 10.12.2)

SLEEVE AND SEALANT
(Section 10.6.4)

WATER SERVICE PIPE TO BUILDING

Figure 1.2.82
THE WATER SERVICE PIPE IN A PUBLIC WATER SUPPLY

Water Supply System: The water service pipe, the water distribution pipes, and the necessary connecting pipes,
fittings, control valves, and appurtenances in or adjacent to the building or premises.

Water Temperature Control Valve: A valve of the pressure balance, thermostatic mixing, or combination
pressure balance/thermostatic mixing type that is designed to control water temperature to reduce the risk of
scalding.

Wet Vent: See "Vent, Wet"

Whirlpool Bathtub: A plumbing appliance consisting of a bathtub fixture that is equipped and fitted with a
circulation piping system, pump, and other appurtenances and is so designed to accept, circulate, and discharge
bathtub water upon each use. See Figure 1.2.83

///////// / / / / 7 / / / / f

Figure 1.2.83
A WHIRLPOOL BATH

2006 Naiionul Siumhrd Plumbing Qide-lllusiraicd

Weir (trap or crown) Discharge overflow of the trap outlet.
Yoke Vent See "Vent, Yoke:

64 2006 National Standard Plumbing Code-Illustrated

Chapter 2

General Regulations

2.1 RESERVED

2.2 RESERVED

2.3 CHANGES IN DIRECTION OF DRAINAGE PIPING

2.3.1 Uses for Drainage Fittings

a. Changes in direction of drainage piping shall be made with long radius drainage fittings. See Table
2.3.1.

EXCEPTION: Short radius drainage fittings shall be permitted in the drain piping for individual fixtures. See
Table 2.3.1.

b. Short radius drainage fittings are those having radius or centerline dimensions that are approximately
equal to or less than their nominal pipe size. The radius or centerline dimensions of long radius drainage
fittings are greater than their nominal pipe size.

c. Long radius drainage fittings shall not be used to connect fixture trap arms to vertical drain and vent
piping. Connections to fixture vents shall be above the top weir of the fixture trap.
See Figures 2.3. 1-A, 2.3.1-B, 2.3. 1-C, and 2.3.1 -D

VERTICAL

■D

VERTICAL

HORIZONTAL

SANITARY TEE

WYE AND 1/8 BEND

SWEEP OR
QUARTER BEND

DOUBLE COMBINATION

NOTES:

1 . Horizontal-to-vertical changes in direction are not as cntical as other changes because gravity
controls the velocity in vertical drops.

2. No-hub cast iron fittings are shown. See Table 2.3.1 for fitting patterns for other drainage pipe
materials.

3. Short pattern fittings are permitted in piping for individual fixtures.

4. Long pattern fittings are not permitted to connect fixture trap arms to vertical and vent piping
because the vent opening at the end of the trap arm will be below the weir of the trap, causing the
trap to self-siphon.

Figure 2.3.1 - A

DRAINAGE FITTINGS FOR HORIZONTAL-TO- VERTICAL

CHANGES IN DIRECTION

2006 Nutioiut! Situu/ard Plumbing Cudc-Illiisiraled

90° LONG SWEEP
OR LONG 1/4 BEND

COMBINATION WYE
& 1/8 BEND

PLAN VIEW

NOTES:

1 . Long pattern fittings are required except short pattern fittings are permitted for individual fixtures,

2. No-hub cast iron fittings are shown. See Table 2.3. 1 for fitting patterns for other drainage pipe
materials.

Figure 2.3.J - B

DRAINAGE FITTINGS FOR HORIZONTAL-TO-HORIZONTAL

CHANGES IN DIRECTION

I- VERTICAL

VERTICAL

COMBINATION WYE
AND 1/8 BEND

HORIZONTAL

L LONG SWEEP
QUARTER BEND
TO BE EQUIVALENT
TO WYE AND
1/8 BEND

WYE AND 1/8 BEND

ELEVATION VIEW

NOTES:

1 . Long pattern fittings are required except short pattern fittings are permitted for individual fixtures.

2. No-hub cast iron fittings are shown. See Table 2.3.1 for fitting patterns for other drainage pipe
materials.

3. See Sections 11.11 and 12.15 for restrictions on branch drain connections near the base of stacks
that are subject to suds pressure.

Figure 2.3.1 - C

DRAINAGE FITTINGS FOR VERTICAL-TO-HORIZONTAL

CHANGES IN DIRECTION

2006 National Standard Plumbing Cude-iitusimicd

•

Table 2.3.1 PERMISSIBLE DRAINAGE FITTINGS FOR CHANGES IN DIRECTION

•

PIPE
MATERIAL

CHANGE IN DIRECTION

HORIZONTAL

TO
HORIZONTAL

HORIZONTAL

VERTICAL

HORIZONTAL

CAST IRON

HUB

SPIGOT

CAST IRON
NO-HUB

long sweep

sanitary tee ( 1 )

eighth bend and wye

short sweep

eighth bend and wye (2)

combination wye & eighth bend

wye

combination wye & eighth bend (2)

long sweep

combination wye & eighth bend

long sweep

short sweep 3" or larger

fifth bend (72-deg)

short sweep

quarter bend (1)

sixth bend (60-deg)

quarter bend (1)

short sweep (1)

eighth bend (45-deg)

sixteenth bend (22 '/i deg)

quarter bend ( 1 )

CAST IRON

DRAINAGE

(threaded)

extra long turn 90-deg elbow

drainage tee (1)

long turn 90-deg TY

long turn 90-deg elbow

short turn 90-deg TY ( I)

extra long turn 90-deg elbow

long turn 45-deg elbow

long turn 90-deg TY (2)

long turn 90-deg elbow

short turn 22 Vi deg elbow

45-deg elbow and 45-deg Y branch (2)

short turn 90-deg elbow ( 1 )

short rum 1 1 Va deg elbow

extra long turn 90-deg elbow

45-deg elbow & 45-deg Y branch (1)

long turn 90-deg TY

long turn 90-deg elbow

short turn 45-deg Y branch

short turn 90-deg elbow (1)

short turn 90-deg elbow ( 1 )

short turn 60-deg elbow ( 1 )

short turn 45-deg elbow ( 1 )

COPPER
DWV

DWV 90-deg long radius elbow

DWV tee (1)

DWV long rum T-Y

90-deg elbow - long radius

DWV 90-deg sanitary tee (1)

45-deg elbow and DWV 45-deg Y

DWV long turn T-Y

DWV long turn T-Y (2)

DWV 90-deg long radius elbow

DWV 45-deg Y

45-deg elbow & DWV 45-deg Y (2)

90-deg elbow - long radius

DWV 90-deg elbow (1)

DWV 90-deg long radius elbow

DWV 90-deg elbow (1)

DWV 45-dcg elbow (1)

90-deg elbow - long radius

DWV 90-deg elbow (1)

PLASTIC
DWV

90-deg long turn elbow

sanitary tee (I)

long radius TY

long sweep 1/4 bend

fixture tee (1)

45-deg elbow and 45-deg wye

60-deg elbow or 1/6 bend

long radius TY (2)

90-deg long turn elbow

45-deg elbow or 1/8 bend

45-deg elbow and 45-deg wye (2)

90-deg elbow or 1/4 bend (1)

22 Vi deg elbow or 1/16 bend

90-deg long turn elbow

long radius TY

90-deg elbow or 1 /4 bend ( 1 )

45-deg wye

90-deg elbow or 1/4 bend (1)

STAINLESS
STEEL

push-fit
DWV

long sweep

tee(l)

eighth bend & wye (2)

wye

sanitary tee (1)

combination wye & eighth bend

eighth bend & wye (2)

long sweep

15-degree 1/24 bend

combination wye & eighth bend

90-degree 1/4 bend(l)

22 Vi degree 1/1 6 bend

long sweep

30-degree 1/12 bend

90-degree 1/4 bend(l)

45-degree 1/8 bend

90-dcgrcc 1/4 bend (1)

Footnotes for Table 2.3. 1

(1) Short radius fittings shall be permitted only in drain piping for individual fixtures.

(2) Long radius fittings shall not be used to connect fixture trap arms to vertical drain and vent piping.

2006 National Standard Plumbing Coile-IIIustratcJ

FROM FiXTURES
UPSTREAM

SHORT PATTERN
(Section 2.3.1)

•

LONG PATTERN
(Section 2.3.1)

SHORT PATTERN

- — FROM FIXTURES UPSTREAM

NOTES:

1 . Short pattern fittings are permitted in drain piping for individual fixtures.

2. Long pattern fittings are not permitted to connect fixture trap arms to vertical drain and vent piping
because the vent opening at the end of the trap arm will be below the weir of the trap, causing the
trap to self-siphon.

Figure 2.3 J - D
USE OF SHORT AND LONG PATTERN DRAINAGE FITTINGS

2.3.2 Double Pattern Fittings

The uses for double pattern drainage fittings shall be the same as for single pattern fittings in Table 2.3. 1 .
EXCEPTION: Double sanitary tees and crosses shall not be used to connect blowout fixtures, back-outlet
water closets, and fixtures or appliances having pumped discharge. See Figure 2.3.2

•

DOUBLE FIXTURE FITTING - ENLARGED

CHAMBER TO PREVENT CROSS-FLOW FROM

ONE FIXTURE TO ANOTHER

DOUBLE COMBINATION WYE & 1/8 BEND

HORIZONTAL DRAINAGE TO

VERTICAL DRAINAGE

NOTES:

1 . Double pattern fittings can be used in horizontal and vertical piping.

Figure 2.3.2
DOUBLE PATTERN DRAINAGE F j TinNGS

2006 Nuiional Standard Plumbing Code-lliaslraieu

•

2.3.3 Back-to-Back Fixtures

Stack fittings, including carriers, for back -outlet fixtures installed back-to-back shall be either the wye pattern,
incorporate baffles within the drainage fitting, or otherwise be designed to prevent crossflow or mixing of the
discharges from the two fixtures prior to the change in direction. See Figure 2.3.3

VERTICAL

2" [

TOP VENT »

BAFFLE BETWEEN
FIXTURE INLETS

BAFFLE BETWEEN INLETS

PART A

VENTED CLOSET CROSS WITH

2 " TOP VENT

VERTICAL
STACK

HORIZONTAL
BRANCH

FIXTURE
INLET

VERTICAL
STACK

HORIZONTAL
BRANCH

PARTB

DOUBLE COMBINATION WYE & 1/8 BEND

HORIZONTAL - TO - VERTICAL

PARTC

DOUBLE COMBINATION WYE & 1/8 BEND

HORIZONTAL - TO - HORIZONTAL

NOTES:

1. No-hub cast iron fittings are shown. See Table 2.3.1 for fitting patterns for other drainage pipe
materials.

2. In Part B, the fixtures must be vented prior to connection to the stack.

3. In Part C. if not battery vented, the fixtures must be individually vented prior to connection to the
branch drain.

Figure 2.3.3
PREVENTING CROSSFLOW BETWEEN BACK-TO-BACK BACK-OUTLET FIXTURES

2006 National Standard Phtmhins Codv-lilustratzd

2.4 FITTINGS AND CONNECTIONS IN DRAINAGE SYSTEMS

2.4.1 Prohibited Fittings

No running threads or saddles shall be used in the drainage or vent system. No drainage or vent piping shall
be drilled, tapped, burned or welded.

2.4.2 Heel or Side-Inlet Bends

A heel or side-inlet quarter bend shall not be used as a dry vent when the inlet is placed in a horizontal
position or any similar arrangement of pipe or fittings producing a similar effect.

EXCEPTION: When the entire fitting is part of a dry vent arrangement system the heel or side-inlet bend
shall be acceptable. See Figures 2.4.2-A and 2.4.2-B

VENT

FIXTURE
DRAIN

PROHIBITED IF NOT
A WET VENT

SIDE INLET
HEEL INLET

Figure 2.4.2 - A
HORIZONTAL HEEL OR SIDE INLET VENT CONNECTION

^\\\N^W

SL — DRY VENT IS ACCEPTABLE
IF HEEL INLET IS VERTICAL

HEEL INLET

Figure 2,4.2 - B
VERTICAL HEEL INLET VENT CONNECTION
2.4.3 Obstruction to Flow

a. No fitting, connection, device, or method of installation that obstructs or retards the flow of water,
wastes, sewage, or air in the drainage or venting systems in an amount greater than the normal fnctional
resistance to flow, shall be used unless it is indicated as acceptable in this Code.

2006 National Standard PInnibiiit> Code-lllusinitcd

•

b. 4x3 closet bends and 4x3 closet flanges shall not be considered as obstructions to flow.

Comment #1: This Section does not prohibit double hub fittings for soil pipe installations since they
create no more restriction to flow that would be encountered with a hubless coupling or similar fitting.

Comment U2: Failure to ream or deburr drainage piping constitutes an obstruction to flow.

2.4.4 Prohibited Joints

Cement mortar joints are prohibited.

EXCEPTION: When used for repairs and/or when used for connections to existing lines constructed with

suchjoints.

2.5 HEALTH AND SAFETY

Where a health or safety hazard is found to exist on a premise, the owner or his agent shall be required to make
such corrections as may be necessary to abate such nuisance, and bring the plumbing installation within the
provisions of this Code.

2.6 TRENCHING, BEDDING, TUNNELING AND BACKFILLING

2.6.1 Trenching and Bedding

a. Trenching and excavation for the installation of underground piping shall be performed in compliance
with occupational safety and health requirements. Trenches shall be of sufficient width to permit proper
installation of the pipe. Where shoring is required, additional allowance shall be made in the width of the
trench to provide adequate clearance.

b. A firm, stable, uniform bedding shall be provided under the pipe for continuous support. Bell holes shall
be provided for joints in bell and spigot pipe and for other joints requiring such clearance. Blocking shall not be
used to support the pipe.

c. The trench bottom may provide the required bedding when adequate soil conditions exist and when
excavated to the proper depth and grade. Where trenches are excavated to depths below the bottom of the
pipe, bedding shall be added beneath the pipe as required. Such bedding shall be of clean sand, gravel, or
similar select material that is compacted sufficiently to provide the support required under 2.6. 1 .b.

d. Where rock is encountered in trenching, it shall be removed to a depth of not less than 6 inches below
the bottom of the pipe and bedding shall be added as required under 2.6.1 x. The pipe shall not rest on rock at
any point, includingjoints.

See Figures 2.6.1-A and 2.6.1-B. Also Sections 2.6.2, 2.6.3, and 2.6.4

2006 National SumJurd Plumbing Code-Illustrated 71

GRADE

fj]= r- SIDE-FILL

1=1

SOIL BEDDING

BACKFILL

SOIL BEDDING

^- ■ j- ' y ' y ^ ^ ^

■-^m'i'm'^FF? 1 ^?' 1 ???!^ 11 ?,

L Tr=FFt7rr=i i i=iTmrf=i 1 i=

PIPE BELLS OR COUPLINGS

NOTES:

1 . The soil under the pipe must be stable. Unstable bedding may damage the pipe, fittings, or joints
when settlement occurs.

2. The side-fill should be shoveled under the pipe to make sure that there are no voids in the side-fill.

Figure 2.6.1 - A
UNDERGROUND PIPING BEDDED ON SOIL

GRADE

SIDE-FILL

™i 1 1-/ 1 i=£rn=i i i=i i i=i i \-

SAND OR GRAVEL BEDDING

BACKFILL

SAND OR GRAVEL
BEDDING

'—1 1 1=1 1 I— I It— 1 1 1— I i I— 1 1 1=1 1 1=1 1 1=1 l)=l 1 1=1 1 1— I II — 1 1 1— 1 1 1=1 1 1=

NOTES:

1 . Unstable bedding may damage the pipe, fittings, or joints when settlement occurs.

2. The side-fill should be shoveled under the pipe to make sure that there are no voids in the side-fill.

Figure 2.6.1 - B
UNDERGROUND PIPING BEDDED ON SAND OR GRAVEL

2.6.2 Side-fill

The haunch areas adjacent to the pipe between the bottom of the pipe and its horizontal centerline shall be
filled with a clean coarse-grain material such as sand, gravel, or soil. Such side-fill shall be placed by hand,
extending to the sides of the trench, and be compacted to provide lateral support for the pipe. See Figure
2.6. 1-A and 2.6.1-B

2006 National Standard Plumbing Code-lUusrraicJ

2.6.3 Initial Backfill

After installation of the side-fill, the trench shall be backfilled to a level not less than 2 feet above the top of
the pipe. Backfill material shall be sand, gravel, or loose soil that is free of rocks and debris. Maximum
particle size shall be 1-1/2 inches. Backfill shall be placed in not more than 6-inch layers, each tamped and
compacted. Heavy compacting equipment shall not be used for the initial backfill. See Figure 2.6.3

urWft

FINAL BACKFILL (Section 2.6.4)

24"

FILL TAMPED IN 6"
LAYERS UNTIL TWO
FEET OF EARTH
COVERS THE PIPE

■i 6"

FT Q | — TJ— 1

NOTES:

1 . The side-fill adjacent to the pipe must be backfilled and tamped to the top of the pipe.

2. The initial backfill must be placed in 6" tamped layers. The use of heavy compacting equipment is
prohibited.

3. The initial backfill material must be sand, gravel, or loose soil from the excavation that is free from
rocks and debris. Broken concrete, frozen earth, and other solid materials may damage the pipe
from point loads.

4. After the pipe is covered with 2 feet of tamped initial backfill, the final backfill to grade can be
compacted with heavy equipment.

Figure 2.6.3
TYPICAL BACKFILLING PROCEDURE

2.6.4 Final Backfill

The trench shall be backfilled from the top of the compacted initial backfill to finish grade using suitable
material. Heavy compacting equipment may be used for the final backfill. See Figure 2.6.3

2.6.5 Tunneling

When pipe is installed in a dug or bored earth tunnel, the space around the pipe between the pipe and the wall
of the tunnel shall be completely filled with packed concrete or grout. When pipe is installed in a jaeked-in-
place conduit or sleeve, the space around the pipe between the pipe and the inside of the conduit or sleeve
shall be sealed in an approved manner in accordance with Section 2.12.d.

2.6.6 Lnderground Plastic Pipe

a. Underground plastic pipe shall be installed in accordance with the requirements of Section 2.6.
EXCEPTIONS:

( i ) The maximum panicle size in the side-fill and initial backfill shall be not more than 1/2-inch for pipe 6"
.size and smaller, and 3/4-inch for pipe 8" and larger.

(2) For water service piping, refer to ASTM D2774, Standard Practice for Underground Installation
of Thermoplastic Pressure Piping.

(3) For gravity-flow drainage pipe, refer to ASTM D2321, Underground Installation of Thermoplastic
Pipe for Sewers and Other Gravity flow Applications.

b. An insulated copper tracer wire or other approved conductor shall be installed adjacent to underground

2006 Nuiional Siaihhnd Plumbing Cod? -illustrated 73

non-metallic water service piping and non-metallic force mains, to facilitate finding. One end shall be brought
above ground inside or outside the building wall. The tracer wire for the water service shall originate at the
curb valve required in Section 10.12.1. The tracer wire for the force main shall originate at the final point of
disposal. The tracer wire shall not be less than 1 8 AWG insulated. The insulation shall not be yellow in color.

2.6.7 Underground Copper Piping

Underground copper piping shall be installed in accordance with the requirements of Section 2.6.
EXCEPTION: The maximum particle size in the side-fill and initial backfill shall be not more than I /2-inch for
pipe 6" size and smaller, and 3/4-inch for pipe 8" and larger.

2.6.8 Safety Precautions

Rules and regulations pertaining to safety and protection of workers, other persons in the vicinity, and neigh-
boring property shall be adhered to where trenching or similar operations are being conducted.

2.6.9 Supervision

Where excavation, bedding or backfilling are performed by persons other than the installer of the underground
piping, the pipe installer shall supervise the bedding, side-fill, and initial backfill, and shall be responsible for its
conformance to this Code.

2.6.10 Trenchless Pipe Replacement Systems

Trenchless replacement of water and sewer piping shall be performed using equipment and procedures
recommended by the equipment manufacturer. Where underground piping beneath paved surfaces or
concrete floor slabs is replaced by this method, the manufacturer's recommendations for the specific condi-
tions shall be used. Approved mechanical couplings shall be used to make the connections between new and
existingpiping.

Comment: When piping beneath paving or concrete floors is replaced by the trenchless method, there
must be sufficient distance above the pipe to prevent cracking the paving or floor slab when the pipe
being replaced bursts.

2.7 SAFETY

Any part of a building or premise that is changed, altered, or required to be replaced as a result of the installation,
alteration, renovation, or replacement of a plumbing system, or any part thereof, shall be left in a safe, non-hazard-
ous condition.

2.8 INSTALLATION PRACTICES

Plumbing systems shall be installed in a manner conforming to this Code and industry installation standards.

2.9 PROTECTION OF PIPES

2.9.1 Breakage

Pipes passing under or through foundation walls shall be protected from breakage.

74 200b National Standard Plumbing Code-lllustniied

2.9.2 Corrosion

Pipe subject to corrosion by passing through or under corrosive fill, such as, but not limited to, cinders, con-
crete, or other corrosive material, shall be protected against external corrosion by protective coating, wrap-
ping, or other means that will resist such corrosion.

Comment #7: Soil samples should be taken to assure that the soil will not corrode the pipe. Wrappings
and coatings reduce contact corrosion, but cathodic protection may be required where stray electric
currents exist.

Comment #2: Job site debris should not be allowed in the backfill for piping trenches. Material such as
metal cans, metal studs, and gypsum board may chemically react with some types of pipe.

2.9.3 Cutting or Notching

Any structural member weakened or impaired by cutting, notching, or otherwise, shall be reinforced, repaired
or replaced, so as to be left in a safe structural condition in accordance with the requirements of the Building
Code or as required by the proper Authority Having Jurisdiction.

2.9.4 Penetration

a. Plastic and copper piping run through framing members to within one inch of the edge of the framing
shall be protected by steel nail plates not less than 1 8 gauge. Where such piping penetrates top plates or sole
plates of the framing, the nail plate shall extend at least two inches below top plates and two inches above
sole plates.

b. Where plastic and copper piping runs through metal framing members, it shall be protected from
abrasion caused by expansion and contraction of the piping or movement of the framing.

2.10 EXCLUSION OF MATERIALS DETRIMENTAL TO THE
SEWAGE SYSTEM

2.10.1 General

No material shall be deposited into a building drainage system or sewer that would or could either obstruct,
damage, or overload such system; that could interfere with the normal operation of sewage treatment pro-
cesses; or that could be hazardous to people or property. This provision shall not prohibit the installation of
special waste systems when approved by the Authority Having Jurisdiction.

2.10.2 Industrial Wastes

Waste products from manufacturing or industrial operations shall not be introduced into the public sewer
system until it has been determined by the Authority Having Jurisdiction that the introduction thereof will not
cause damage to the public sewer system or interfere with the functioning of the sewage treatment plant.

Comment: Where industrial wastes will be created, the facility should provide the following information
to the Authority Having Jurisdiction for the sewerage system: (1) the quantity of water and waste
material that will be discharged into the sewer system, (2) the industrial processes that create the waste,
(3) the composition and concentration of the chemicals in the waste, (4) the water supply demand for the
facility, and (5) the intended design of the pre-treaiment or neutralizing system for the wastes prior to its
discharge into the sewer system.

2006 National Standard Plumbing Code- Musi rated 75

2.11 PIPING MATERIALS EXPOSED WITHIN PLENUMS:

All piping materials exposed within plenums shall comply with the provisions of other applicable Codes.

2.12 SLEEVES

a. Ail piping passing through concrete walls, floors, slabs, and masonry walls shall be provided with sleeves
for protection.

EXCEPTION: Sleeves shall not be required for pipes passing through drilled or bored holes. Such holes shall
provide 1/2 inch minimum clearance around the pipe and any thermal insulation.

b. Sleeves shall be sized so there is a minimum of 1/2-inch clearance around the pipe and/or insulation.

c. Piping through concrete or masonry walls shall not be subject to any load from building construction.

d. The annular space between sleeves and pipes shall be filled or tightly caulked with coal tar. asphalfum
compound, lead, or other material found equally effective and approved as such by the Authority Having
Jurisdiction.

e. All penetrations of construction required to have a fire resistance rating shall be protected in accordance
with the applicable building regulations.

See Figure 2.12

SLEEVES MUST BE SIZED

SO THERE IS A MINIMUM OF 1/2 INCH

CLEARANCE AROUND PIPE

NOTES:

1 . The sleeve must be sealed where necessary to prevent the entrance of ground water into the
building.

Figure 2.12
A PIPE SLEEVE THROUGH A FOUNDATION WALL

2.13 OPENINGS FOR PIPING

a. Openings for plumbing piping shall be sealed as required to maintain the integrity of the wall, floor, ceiling,
or roof that has been penetrated.

b. Collars or escutcheon plates shall be provided to cover the openings around pipes where the piping pen-
etrates walls, floors, or ceilings in finished areas that are exposed to view.

2.14 USED MATERIAL OR EQUIPMENT

Used plumbing material or equipment that does not conform to the standards and regulations set forth in this
Code shall not be installed in any plumbing system.

2.15 CONDEMNED EQUIPMENT

Any plumbing equipment condemned by the Authority Having Jurisdiction because of wear, damage, defects or
sanitary hazards, shall not be used for plumbing purposes.

2006 National Sumdard Plumbing Code- Illustrated

2.16 FREEZING <>R OVERHEATING

a. The plumbing system shall be protected from freezing or overheating. The following conditions shall be met:

1 . Water service piping shall be installed below recorded frost lines. Minimum earth cover shall be

inches.

2. Minimum earth cover for building sewers that connect to public sewage systems shall be inches.

Minimum earth cover for building sewers that connect to individual sewage disposal systems shall be inches.

3. In systems that are used seasonally, water piping shall be installed to be drained.

4. Piping shall be installed so that the contents will not be heated due to close proximity to any heat source or
from direct solar radiation.

5. In areas with seasonal freezing temperatures, all waste and water supply piping in exterior walls and other
areas shall be protected from freezing.

See Figure 2.16

FINISHED GRADE

DISTANCES X AND Y ARE
GROUND COVER, NOT •
TRENCH DEPTH

NOTES:

1 . Refer to the adopting ordinance for this Plumbing Code to determine the minimum required cover for
water service and sewer piping.

2. Locating piping in exterior walls where freezing is possible should be avoided if possible. Thermal
insulation only retards the loss of heat, it does not prevent it.

3. Heat tracing may be required where piping is exposed outdoors or in unheated spaces.

Figure 2.16
DEPTH OF COVER FOR WATER SERVICE AND SEWER PIPING

2.17 PROTECTING FOOTINGS

Trenching parallel to and below the bottom of footings or walls shall not penetrate a 45° plane extending outward
from the bottom corner of the footing or wall, unless the soil type is approved by the Authority Having Jurisdiction
for a different angle of repose. See Figure 2.17

2006 Nuiiaiuil Standard Plumbing Code-lHusiraied

BUILDING WALL,
COLUMN, OR
OTHER STRUCTURAL
MEMBER <

EXCAVATION

SOIL TYPE AND CONDITION
MAY PERMIT OR REQUIRE A
DIFFERENT ANGLE OF REPOSE

NOTES:

1 . Check the project design documents to verify that a 45 degree angle of repose is permissible.

2. Consult the project structural engineer if conditions dictate that excavations must be closer
than 45 degrees from the bottom edge of footings.

Figure 2.17
PROTECTING STRUCTURAL FOOTINGS FROM BEING UNDERMINED

2.18 CONNECTIONS TO PLUMBING SYSTEMS REQUIRED

Every plumbing fixture, drain, appliance, or appurtenance thereto that is to receive or discharge any liquid waste or
sewage shall discharge to the sanitary drainage system of the building in accordance with the requirements of this
Code.

2.19 CONNECTION TO WATER AND SEWER SYSTEMS

2.19.1 Availability of Public Water and Sewer

The water distribution and drainage systems of any building in which plumbing fixtures are installed shall be
connected to a public water supply and sewer system respectively if the public water supply and/or public
sewer is within feet of any property line of the premises, or other reasonable distance as determined

by the Authority Having Jurisdiction. See Figure 2.19.1

PUBLIC SEWER

NOTES:

1 . Refer to the adopting ordinance for this Plumbing Code to determine the distance from which
properties must be connected to public water and sewer systems.

2. Connections to public water and sewer systems are more desirable than private systems, from the
standpoint of public health and convenience.

Figure 2.19.1
REQUIRED CONNECTION OF PROPERTIES TO PUBLIC WATER AND SEWER SYSTEMS

2006 National Standard Plnmbinv Coite-lllusiroicd

2,19.2 Private Systems

Where either a public water supply or sewer system, or both, are not available^ a private individual water
supply or individual sewage disposal system, or both, shall be provided, and the water distribution system and
drainage system shall be connected thereto. Such private systems shall meet the standards for installation and
use established by the Health Department or other agency having jurisdiction. (See Chapters 1 6 and 1 7.) See
Figure 2.19.1. Also the definitions of "Private Sewage Disposal System" and "Private Water
Supply".

Comment: Plumbing in buildings connected to private water or sewage systems must comply with all
applicable requirements of this Code or the Authority Having Jurisdiction.

2.20 WASHROOM & TOILET ROOM REQUIREMENTS

•

2.20.1 Light and Ventilation

Light and ventilation shall be provided as required by other applicable codes.

2.20.2 Location ofPiping and Fixtures

Piping, fixtures, or equipment shall not be located in such a manner as to interfere with the normal operation
of windows, doors, or other exit openings.

2.21 PIPING MEASUREMENTS

Except where otherwise specified in this Code, all measurements shall be made to the center lines of the pipes.

2.22 WATER CLOSET CONNECTIONS

a.Three-mcb bends may be used on water closets or similar connections provided a 4-inch by 3-inch flange is
installed to receive the ciose.t fixture horn.
b. Four-inch by three-inch closet bends shall be permitted.
See Figures 2.22

4" NOM.

WLM FINISHED FLOOR

3" NOM.

NOTES:

1 . Reducing fixture drains for water closets from 4" to 3" is permissible.

Figure 2.22
WATER CLOSET DRAIN CONNECTIONS

2006 Naliomil Standard Plumbing Cucie-liluiirateJ

2.23 DEAD ENDS

a. In the installation or removal of any part of a drainage or vent system, dead ends shall be avoided.
EXCEPTION: Where necessary to extend a cleanout so as to be accessible.

b. In the installation or removal of any part of a potable water system, dead ends shall be avoided See
Figure 2.23 and the definition of "Dead End".

Comment: Rough-ins for future fixtures are not considered dead ends if the piping is accessible and can
he cleared of any blockages when the future fixtures are installed.

2.24 TOILET FACILITIES FOR CONSTRUCTION WORKERS

Suitable toilet facilities shall be provided and maintained in a sanitary condition for the use by workers during
construction. Non-sewer type toilet facilities for construction workers shall conform to ANSI Z4.3.

2.25 FOOD HANDLING AREAS

a. Food or drink shall not be stored, prepared or displayed beneath overhead sewer or drain pipes unless such pipes
are protected against leakage or condensation reaching the food or drink as described below for new construction.
In newly constructed or remodeled establishments, soil or drain pipes located over food preparation, storage,
display or serving areas are undesirable. Where building design requires that soil or drain pipes be located over
such areas, the installation shall be made with the least possible number of joints and shall be installed so as to
connect to a vertical stack at the nearest wall or vertical building support and the construction shall be performed
as follows:

1 . All openings through floors over such areas shall be provided with sleeves securely bonded to the floor
construction and projecting not less than 3/4 inch above top of the finished floor with space between sleeve and
pipe or duct sealed.

2. Floor and shower drains installed above such areas shall be equipped with integral seepage pans.

3. Plumbing fixtures in rooms located above such areas shall be of the wall mounted type except bathtubs. Tubs
shall have waste and overflow connections made above floor and piped to the trap below the floor. Connections
through floors and traps shall conform with all other provisions of this regulation. No floor openings, other than
sleeve for waste pipe, will be permitted for rubs.

4. All other soil or drain pipes shall be of an approved material as listed in Table 3. 1.3 and Section 11.1. All
materials shall conform to established standards. Cleanouts shall be extended through the floor construction above.

5. Soil and drain pipes located above such areas shall be subjected to a standing water test of not less than 25
feet.

6. Piping subject to operation at temperatures that will form condensation on the exterior of the pipe shall be
thermally insulated.

7. Where pipes are installed in ceilings above such areas, the ceiling shall be of the removable type, or shall be
provided with access panels in order to form a ready access for inspection of piping.

8. In lieu of the above, any other method may be approved by the Authority Having Jurisdiction that does not
conflict with applicable health codes.

9. The installation of vacuum collection systems in buildings where food is prepared, stored or displayed shall be
permitted provided that the system is under constant vacuum. The piping shall be smooth bore and long pattern
fittings shall be used. Bracing shall be in accordance with the manufacturer's instructions.

1 0. Floor sinks in food handling areas shall be of the sanitary design with smooth, corrosion-resistant interior
surfaces that can be readily cleaned.

See Figures 2.25 - A and 2.25 - B

80 2006 National Standard Pliirnbini; Cude-lllusmncJ

•

FILLER MATERIAL - WATERTIGHT
AND SEALED ACCORDING TO
FIRE AND BUILDING CODES

NOTES:

1 . The 3/4" extended sleeve prevents spillage on the floor above from leaking down into the food
handling area and contaminating the food products.

Figure 2.25 - A
A PIPE PENETRATION OF A FLOOR ABOVE A FOOD HANDLING AREA

SEE FIGURE 2.25A

PIPING IS IN CEILING SPACE
PIPING MUST BE ACCESSIBLE

NOTES:

1 . All pipe penetrations through the floor above must have extended pipe sleeves. See Figure 2.25 - A.
The number of floor penetrations should be minimized.

2. Floor -outlet water closets are not permitted above a food handling area.

3. Bathtubs and showers must have above-the-floor waste outlets with piping extended to a point
where an extended pipe sleeve can be installed.

4. Piping run in a ceiling space above a food handling area must be fufly accessible.

Figure 2.25 - B
PLUMBING FIXTURES ABOVE A FOOD HANDLING AREA

2006 Nultomil Standard Plumbing Code-illuslmieJ

Blank Page

200(> National Slandunl Plumbing CoJt-UlusiniicJ

•

Chapter 3

Materials

3.1 MATERIALS

3.1.1 Minimum Standards

The standards cited in this chapter shall control all materials, systems, and equipment used in the construction,
installation, alteration, repair, or replacement of plumbing or drainage systems or parts thereof.
EXCEPTIONS:

(1 ) The Authority Having Jurisdiction shall allow the extension, addition to or relocation of existing water,
soil, waste, drainage and vent pipes with materials of like grade or quality as permitted in Section 3.12.2.

(2) Materials not covered by the standards cited in this chapter may be used with the approval of the
Authority Having Jurisdiction as permitted in Section 3.12.2.

3.1.2 General Requirements

a. Materials, fixtures, or equipment used in the installation, repair or alteration of any plumbing system
shall conform at least to the standards listed in this chapter, except as otherwise approved by the Authority
Having Jurisdiction under the authority contained in Section 3.12.

b. Materials installed in plumbing systems shall be so handled and installed as to avoid damage so that the
quality of the material will not be impaired.

c. No defective or damaged materials, equipment or apparatus shall be installed or maintained. (See
Sections 2. 1 4 and 2. 1 5)

d. All materials used shall be installed in strict accordance with the standards under which the materials
are accepted and approved, including the appendices of the standards, and in strict accordance with the
manufacturer's instructions. Where the provisions of material standards or manufacturer's instructions
conflict with the requirements of this Code, this Code shall prevail.

3.1.3 Standards Applicable to Plumbing Materials

A material shall be considered approved if it meets one or more of the standards cited in Table 3.1 .3, and in the
case of plastic pipe, also the listed standard of the NSF International. Materials not listed in Table 3.1.3 shall be
used only as provided for in Section 3.12.2 or as permitted elsewhere in this Code.

Note: Abbreviations in Table 3.1 .3 refer to the following organizations:

AHAM Association of Home Appliance Manufacturers
1111 19th Street, NW - Suite 402
Washington, DC 20036 USA
tel: 1-202-872-5955
fax:1-202-872-9354

2006 National Standard Plumbing, Code-Illustrated

ANSI

ASME

ASSE

ASTM

AWWA

C1SPI

CSA

American National Standards Institute
25 West 43rd Street - 4th Floor
New York, NY 10036 USA
tel: 1-212-642-4900
fax:1-212-398-0023

ASME International
Three Park Avenue
New York, NY 10016-5990
tel: 1-800-843-2763
fax:1-212-591-7674

USA

ASSE International

901 Canterbury Road - Suite A

Westlake, OH 44145 USA

tel: 1-440-835-3040

fax:1-440-835-3488

ASTM International

100 Barr Harbor Drive - PO Box C700

West Conshohocken, PA 19428-2959

USA

tel: 1-610-832-9585

fax:1-610-832-9555

American Water Works Association
6666 W. Quincy Avenue
Denver, CO 80235 USA
tel: 1-800-926-7337
fax:1-303-347-0804

Cast Iron Soil Pipe Institute
5959 Shallowford Road - Suite 4 1 9
Chattanooga, TN 37421 USA
tel: 1-423-892-0137
fax:1-423-892-0817

Canadian Standards Association

5060 Spectrum Way

Mississauga, ON L4W 5N6

CANADA

tel: 1-800-463-6727

fax:1-416-747-2473

IAPMO International Association of

Plumbing and Mechanical Officials
5001 E. Philadelphia Street
Ontario, C A 91761 USA
tel: 1-909-472-4100
fax:1-909-472-4150

I SEA International Safety Equipment

Association
1901 N. Moore Street
Arlington, VA 22209-1762 USA
tel: 703-525- 1695
fax:703-528-2148

MSS Manufacturers Standardization Society

127 Park Street NE
Vienna, VA 22180 USA
tel: 1-703-281-6613
fax:1-703-281-6671

NFPA National Fire Protection Association

1 Batterymarch Park
Quincy, MA 02169-7471 USA
tel: 1-617-770-3000
fax:1-617-770-0700

NSF NSF International

789 N. Dixboro Road

Ann Arbor, MI 48113-0140 USA

tel: 1-800-673-6275

fax:1-734-769-0109

PDI Plumbing & Drainage Institute

800 Turnpike Street - Suite 300
North Andover, MA 01845 USA
tel: 1-800-589-8956
fax:1-978-557-0721

UL Underwriters Laboratories Inc.

333 Pfingsten Road
Northbrook, IL 60062-2096 USA
tel: 1-847-272-8800
fax:1-847-272-8129

FM FM Global

1301 Atwood Avenue - PO Box 7500
Johnston, RI 02919 USA
tel: 1-401-275-3000
fax:1-401-275-3029

2006 National Slandurd Plumbine Code-Illustrated

3.1 .4 Identification of Materials

Materials shall be identified as provided in the standard to which they conform.

3.2 SPECIAL MATERIALS

3.2.1 Miscellaneous Materials

Sheet and tubular copper and brass for the following uses shall be not less than:

a. General use - 12 oz. per square foot

b. Flashing for vent pipes - 8 oz. per square foot

c. Fixture traps and trap arms - 1 7 gauge or ASME Al 1 8.2/CSA B 125.2

d. Fixture tailpieces - 20 gauge or ASME Al 1 8.2/CSA B 125.2

e. Tailpieces with dishwasher connections - 20 gauge or ASME Al 1 8.2/CSA B 125.2

f. Continuous wastes - 20 gauge or ASME Al 1 8.2/CSA B 125.2

3.2.2 Lead

See Table 3.1 .3. Sheet lead shall be not less than the following:

a. Shower pans — not less than 4 pounds per square foot (psf) and be coated with an asphalt paint or
equivalent.

b. Flashings of vent terminals — not less than 3 pounds per square foot (psf).

c. Lead bends and lead traps shall not be less than ]/8" wall thickness.

3.2.3 Plastic

a. Trap and tailpiece fittings — minimum 0.062" wall thickness.

b. Piping — see specific application — Sections 3.4 to 3.1 1 .

c. Shower pans — approved plastic sheeting material.

Comment: Plastic shower pans should not be covered with asphalt unless recommended by the manu-
facturer.

3.3 FITTINGS, FIXTURES, APPLIANCES & APPURTENANCES

3.3.1 Drainage Fittings

See Sections 2.3 and 2.4 for fittings and connections in drainage systems.

3.3.2 Cleanout Plugs and Caps

a. Cleanout plugs shall be of brass, plastic, stainless steel, or other approved materials and shall have
raised or countersunk square heads, except that where raised heads will cause a tripping hazard, countersunk
heads shall be used.

b. Cleanout caps shall be of brass, plastic, reinforced neoprene, cast-iron, or other approved material and
shall be readily removable.

See Figure 3.3.2

2006 National Standard Plumbing Code-lflustraied 85

COUNTERSUNK HEAD PLUG

RAISED HEAD PLUG

Figure 3.3.2
CLEANOUT PLUGS

3.3.3 Fixtures

a. Plumbing fixtures shall be constructed from approved materials having smooth, non-absorbent surfaces
and be free from defects, and except as permitted elsewhere in this Code, shall conform to the standards
cited in Table 3.1.3.

b. Materials for special use fixtures not otherwise covered in this Code shall be constructed of materials
especially suited to the use for which the fixture is intended.

See Chapter 7 for the requirements for specific fixtures

Comment #1: The standards for plumbing fixtures that are listed in Table 3. 1.3 reflect consensus
agreement between manufacturers! industry representatives, and consumer groups.

Comment #2: Slip resisting surfaces in bathtubs and showers do not constitute a violation of the require-
ment for smooth surfaces.

3.3.4 Floor Flanges and Mounting Bolts

a. Floor flanges for water closets or similar fixtures shall be not less than 1/8" thick for brass, 1/4" thick
and not less than 1-1/2" caulking depth for cast-iron or galvanized malleable iron. Approved copper and plastic
flanges may be used.

b. If of hard lead, they shall weigh not less than 1 lb. 9 oz. and be composed of lead alloy with not less
than 7.75 percent antimony by weight. Flanges shall be soldered to lead bends or shall be caulked, soldered, or
threaded into other metal.

c. Closet screws and bolts shall be corrosion-resisting.

d. Connections between drainage piping and floor outlet water closets shall be made by means of an
approved flange that is attached to the drainage piping in accordance with the provisions of this chapter. The
floor flange shall be set on and securely anchored to the finished floor.

3.3.5 Flush Pipes and Fittings

Flush pipes and fittings shall be of nonferrous material. When of brass or copper tube, the material shall be at
least 0.0313" in thickness (No. 20 U.S. gauge).

3.3.6 Reserved

3.3.7 Interceptors

Interceptors shall meet the requirements of Chapter 6.

2006 National Standard Plumbing Code-Illustrated

3.3.8 Pressure Tanks and Vessels

a. Hot water storage tanks shall meet construction requirements of ASME, AGA or UL as appropriate.
(See Table 3.1.3)

b. Storage tanks less in volume than those requirements specified by ASME shall be of durable materials
and constructed to withstand 125 p.s.i. with a safety factor of 2.

3.3.9 RoofDrains

Roof drains shall be of cast-iron, copper, lead, or other approved corrosion-resisting materials. See Section
13.5.1

3.3.10 Safety Devices for Pressure Tanks

Safety devices shall meet the requirements of the American National Standards Institute, American Society
of Mechanical Engineers, or the Underwriters Laboratories. Listing by Underwriters Laboratories, American
Gas Association or National Board of Boiler and Pressure Vessel Inspectors shall constitute evidence of
conformance with these standards. Where a device is not listed by any of these, it shall have certification by
an approved laboratory as having met these requirements. (See Section 10.16.)

3.3.11 Septic Tanks

a. Plans for all septic tanks shall be submitted to the Authority Having Jurisdiction for approval. Such plans
shall show all dimensions, reinforcing, structural calculations and such other pertinent data as may be re-
quired.

b. Septic tanks shall be constructed of sound durable materials, not subject to excessive corrosion or decay
and shall be watertight. (See Sections 16.6.5 and 16.6.6.)

3.3.12 Carriers and Supports

Carriers and supports for plumbing fixtures shall comply with ASME A 1 1 2.6. 1 , ASME A 1 1 2.6.2 or ASME
Al 12.19.12.

3.4 POTABLE WATER PIPING

3.4.1 PlasticPiping

Plastic piping materials used for the conveyance of potable water shall comply with NSF 14 and be marked
accordingly.

3.4.2 Water Service Piping

Water service piping to the point of entrance into the building shall be of materials listed in Table 3.4. and shall
be water pressure rated not less than 160 psi at 73°F. See Table 3.4.2.

Comment: The manufacturer's markings on plastic water service pipe must indicate that it is suitable for
160psig @ 73°F.

3.4.3 Water Distribution Piping

Water piping for the distribution of hot or cold water within buildings shall be of materials listed in Table 3.4.
and shall be water pressure rated for not less than 100 psi at 1 80°F. Plastic piping used for hot water distribu-
tion shall be installed in accordance with the requirements of Section 10.15.8.

2006 National Standard Plumbing Code-Illustrated 87

NOTE: The working pressure rating for certain approved plastic piping materials varies depending on pipe
size, pipe schedule and methods of joining. See Table 3.4.3.

3.4.4 Fittings

Fittings for water supply piping shall be compatible with the pipe material used.

3.4.5 Material Ratings and Installation

a. Piping used for domestic water shall be suitable for the maximum temperature, pressure, and velocity
that may be encountered, including temporary increases and surges.

b. Relief valve temperature and pressure relief settings shall not exceed the approved standard rating for
hot and cold water distribution piping.

c. Pipe and fittings shall be installed in accordance with the manufacturer's installation instructions and the
applicable material standards, recognizing any limitations in use.

Comment: Refer to the standards listed in Table 3.1.3 to determine the pressure and temperature ratings
of the various piping materials.

3.4.6 Limit on Lead Content

a. Materials used in the potable water supply system, including faucets and valves, shall not contain more
than 8 percent lead.

b. Drinking water system components shall comply with the lead leachate requirements as specified for
covered products of NSF International 61.

See Section 4.2.4 for the limit on lead in solder filler metal

Comment: The limit of 8% lead is based on the EPA Safe Drinking Water Act. Generally, fixture fitting
castings do not exceed 7% lead.

3.5 SANITARY DRAINAGE PIPING

3.5.1 Aboveground Piping- Soil, Waste and Indirect Waste

Aboveground soil and waste piping within buildings shall be of materials listed in Table 3.5.

3.5.2 Underground Building Sanitary Drains

Underground building drains and other underground sanitary drain and waste piping within buildings shall be of
materials listed in Table 3.5.

3.5.3 Building Sanitary Sewer

Sanitary sewer piping outside of buildings shall be of materials listed in Table 3.5. Joints shall be watertight
and root proof.

3.5.4 Plastic Piping

a. Pipe and fittings classified by standard dimension ratio that are underground outside of buildings shall be
SDR 35 or heavier (lower SDR number). Pipe and fittings within buildings shall be SDR 26 or heavier (lower
SDR number).

b. Pipe and fittings classified by pipe stiffness that are underground outside of the buildings shall be PS-45
or heavier (higher PS number). Pipe and fittings within buildings shall be PS-100 minimum.

88 2006 National Standard Plumbing Code-Illustrated

3.5.5 Vitrified Clay Pipe

Vitrified clay pipe shall be joined using compression joints or couplings. Vitrified clay pipe installed under-
ground within buildings shall be extra strength and shall have 12" minimum earth cover.

3.5.6 Fittings

Fittings in drainage systems shall be compatible with the pipe used and shall have no ledges, shoulders, or
reductions that can retard or obstruct flow. Threaded fittings shall be the recessed drainage type.

3.6 VENT PIPING

3.6.1 Aboveground Piping

Aboveground vent piping in buildings serving sanitary, waste, or storm drainage systems shall be of materials
listed in Table 3.6.

3.6.2 Underground Piping

Vent piping installed underground shall be of materials listed in Table 3.6.

3.6.3 Plastic Piping

b. Pipe and fittings classified-by pipe stiffness that are underground outside of buildings shall be PS-45 or
heavier (higher PS number). Pipe and fittings within buildings shall be PS-100 minimum.

3.6.4 Fittings

Fittings in vent piping shall be compatible with the pipe material used. Where threaded pipe is used, fittings
shall be either the drainage or pressure type, galvanized or black.

3.7 STORM DRAINAGE PIPING

3.7.1 Exterior Gutters and Leaders

Exterior gutters and rain leaders shall be of galvanized sheet metal, aluminum, plastic or other approved
material.

3.7.2 Interior Conductors

Stormwater drain piping installed aboveground in buildings shall be of materials listed in Table 3.7.

3.7.3 Underground Building Storm Drains

Underground building storm drains and other underground stormwater piping within buildings shall be of
materials listed in Table 3.7.

3.7.4 Building Storm Sewer

Building storm sewer piping outside of buildings shall be of materials listed in Table 3.7.

2006 National Standard Plumbing Code-Illustrated 89

3.7.5 Plastic Piping

b. Pipe and fittings classified by pipe stiffness that are underground outside of buildings shall be PS-45 or
heavier (higher PS number). Pipe and fittings within buildings shall be PS-100 minimum.

3.7.6 Vitrified Clay Pipe

Vitrified clay pipe shall be joined using compression joints or couplings. Vitrified clay pipe installed under-
ground within buildings shall be extra strength and shall have 12" minimum earth cover.

3.7.7 Fittings

3.8 FOUNDATION DRAINS AND SUBSOIL DRAINAGE

Piping for foundation drains and other subsoil drainage shall be of materials listed in Table 3.8.

3.9 AIR CONDITIONING CONDENSATE DRAIN PIPING

Indirect waste piping from air conditioning unit drains to the point of disposal shall be of a material approved for
either potable water, sanitary drainage or storm drainage.

3.10 CONDENSATE DRAINS FROM COMBUSTION PROCESSES

Piping used to convey condensate from combustion processes (such as from flues and chimneys) shall conform to
the equipment manufacturer's instructions.

3.11 CHEMICAL AND SPECIAL WASTE SYSTEMS

3.11.1 Drain Piping

Separate drainage systems for chemical wastes shall be of corrosion resistant material approved by the
Authority Having Jurisdiction. Materials acceptable for chemical waste drainage systems include chemically
resistant glass pipe, high silicon content cast-iron pipe, vitrified clay pipe, plastic pipe, plastic lined pipe, Type
3 1 6L stainless steel DW V pipe, and lead pipe.

3.11.2 VentPiping

Vent piping on chemical waste systems shall conform to that required for chemical waste pipe except as may
be otherwise authorized by the Authority Having Jurisdiction, and shall be installed independently through the
roof.

3.12 ALTERNATE MATERIALS AND METHODS

3.12.1 Existing Buildings

a. Plumbing work performed in existing buildings shall conform to the requirements of this Code, unless
the Authority Having Jurisdiction finds that such conformance would result in an undue hardship.

b. The Authority Having Jurisdiction may grant a variation to the extent necessary to relieve the undue
nature of the hardship.

c. A record, open to the public, shall be kept of each variation granted under this section.

90 2006 National Standard Plumbing Code- Illustrated

•

3.12.2 Approval

a. The Authority Having Jurisdiction may approve the use of any material or method not expressly con-
forming to the requirements of this Code provided all of the following conditions are met:

1 . The material or method is not expressly prohibited by this Code.

2. The material or method is determined to be of such design or quality as to appear suitable for the
proposed use.

3. A record of such approval is kept and shall be available to the public.

3.12.3 Tests

When there is insufficient evidence to verify claims for alternate materials, the Authority Having Jurisdiction
may require tests of compliance as proof of suitability. Such tests shall be made by an approved testing
agency at the expense of the applicant.

3.12.4 Test Procedure

Tests shall be made in accordance with approved standards; but in the absence of such standards, the Au-
thority Having Jurisdiction shall specify the test procedure.

3.12.5 Repeated Tests

The Authority Having Jurisdiction may require tests to be repeated if, at any time, there is reason to believe
that an alternate material no longer conforms to the requirements on which its approval was based.

2006 National Standard Plumbing Code Illustrated 91

Table 3.L3
STANDARDS FOR APPROVED PLUMBING MATERIALS AND EQUIPMENT

I f FRROLS PIPE \NDHr HNGS

Hub & Spigot Cast-iron Soil Pipe and Fittings:

ASTMA74-05.

Hubless Cast-Iron Soil Pipe and Fittings:

CISPI 301-05, ASTM A888-05.

Ductile-IronPressurePipe:

ASTMA377-03, AWWAC151/A21.51-02.

Ductile-Iron and Gray-Iron Fittings (3" and larger):

A WW A CI 10/A21. 10-03.

Cement-Mortar Lining for Ductile-Iron Pipe and Fittings:

AWWA CI 04/A2L4-03.

Steel Pipe, Galvanized, Welded and Seamless:

ASTM A53/A53M-04a, ASMEB36.1M-
2004

Cast-Iron Threaded Drainage Fittings:

ASME Bl 6.1 2-1998.

Cast-Iron Threaded Fittings, Classes 1 25 and 250:

ASME B16.4-1 998.

Malleable-Iron Threaded Fittings, Class 1 50 and 300:

ASMEB16.3-1998.

Ferrous Pipe Plugs, Bushings, and Locknuts with Pipe Threads:

ASMEB16.14-1991.

Stainless Steel DWV Pipe and Fittings, Types 304 and 3 1 6L (3)

ASME All 23.1-1993

it* jtt^-FraROIft MET Ar J '^j^AI^vMtTOGS " 4 "^ * ^ * • ^

Brass Pipe, Red, Seamless, Standard Sizes:

ASTM B43-98(R2004).

Cast Bronze Threaded Fittings, Classes 1 25 & 250:

ASME B16.15-1985(R2004).

Cast CopperAUoy Pipe Flanges, Class 150,300,400,600,900, 1500,
2500, and Flanged Fittings, Classes 1 50 and 300:

ASME Bl 6.24.2001.

Cast Copper Alloy Solder Joint Drainage Fittings- DWV:

ASME BI 6.23-2002.

Cast Copper Alloy Solder Joint Pressure Fittings:

ASMEB16.18-2001.

Copper Drainage Tube (DWV);

ASTM B306-02.

Copper Pipe, Seamless, Standard Sizes:

ASTMB42-02.el

CopperPipe,Threadless(TP):

ASTM B302-02.

Copper Water Tube, Seamless (K, L, M):

ASTM B88-03.

Grooved & Shouldered Joints (split couplings, for copper tube):

AWWAC606-04.

Wrought Copper and Wrought Copper Alloy Solder Joint Drainage
Fittings- DWV:

ASME Bl 6.29-2001.

Wrought Copper and Copper Alloy Solder Joint Pressure Fittings:

ASME Bl 6.2 2-2001.

Reserved

Cast Copper Alloy Fittings for Flared Copper Tubes:

ASME Bl 6.26-1 998.

Wrought Copper and Copper Alloy Braze- Joint Pressure Fittings:

ASMEB16.50.2001.

•

1006 National Standard Plnmbine Code-Illustrated

\ , ,'« ■• : -" ; : : •] ' ■ r > iii, ^ -Noi^if aljCIc pipe and JixriNGS J - $r ; '•',;■> ^ .^|j|

Acrylonitrile-Butadiene-Styrene(ABS) Plastic Pipe(SDR-PR)(l/8"- 12"):

ASTM D2282-(2005)

Acrylonitrile-Butadiene-Styrene(ABS) Plastic Pipe, Schedules
40 and 80(1/8"-! 2"):

ASTMD!527-99el.

Reserved

Aciylonitrile-Butadiene-Styrene(ABS)Schedule40PlasticDrain,
Waste, and Vent Pipe and Fittings ( 1-1/4"- 6"):

ASTMD2661-02.

Acrylonitrile-Butadiene-Styrene(ABS) Schedule 40 Plastic
Drain, Waste, and Vent Pipe With a Cellular Core ( 1-1/4"- 6"):

ASTMF628-01.

Aery lonitrile-Butadiene-Styrene ( ABS) Sewer Pipe and fittings (3"- 1 2"):

ASTMD2751-05.

AcryIonitrile-Butadiene-Styrenc(ABS)andPoly (Vinyl Chloride)(PVC)

Composite Sewer Pipe (6"- 15").'

ASTMD2680-0L

Poly (Vinyl Chloride) (PVC) Pressure Pipe for Water (4"- 12"):

AWWAC90O-97

Poly (Vinyl Chloride)(PVC)Plastic Pipe, Schedules 40, 80, and
120(1/8"- 24"):

ASTM D 1785-05.

Poly (Vinyl Chloride)(PVC)Plastic Pipe Fittings, Scheduled;
socket-type (1/8" -8"):

ASTMD2466-05.

Poly (Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 80;
socket-type (1/8"- 8"):

ASTMD2467-04el.

Poly (Vinyl Chloride) (PVC) Plastic PipeFittings, Schedule 80,
Threaded (1/8"- 6"):

ASTMD2464-99el.

Poly (Vinyl Chloride) (PVC) Pressure-Rated Pipe, (SDR Series) ( 1 IS"- 36"):

ASTMD2241-04b.

Poly (Vinyl Chloride)(PVC)PlasticDrain, Waste, and Vent
PipeandFittings( 1-1/4"- 12"):

ASTMD2665-04ael.

Poly (Vinyl Chloride) ( PVC) Schedule 40 Drainage and DWV
Fabricated Fittings:

ASTM Fl 866-05.

3.25" OutsideDiameter Poly (Vinyl Chloride) (PVC)
Plastic Drain, Waste, and Vent Pipe and Fittings:

ASTMD2949-01ael.

Poly (Vinyl Chloride) (PVC) Sewer Pipe and Fittings (2"-6"):

ASTMD2729-03.

Poly (Vinyl Chloride)(PVC)Gasketed Sewer Fittings(4"-27"):

ASTM Fl 336-02.

Coextruded Poly (Vinyl Chloride) (PVC) Plastic Pipe witha
Cellular Core; Non-Pressure Uses, IPS Schedule 40 ( 1 - 1 /4"- 1 2"):

ASTMF891-04.

Coextruded Poly (Vinyl Chloride)(PVC)Plastic Pipe with a Cellular Core;
Non-Pressure Uses, PS and Sewer/Drain Series (2"- 1 8 M ):

ASTMF891-04.

Reserved

Type PSM Poly (Vinyl Chloride) (PVC) Sewer Pipe and Fittings (4"- 1 5"):

ASTM D3034-04a,

Chlorinated Poly ( Viny! Chloride) (CPVC) Plastic Hot- and Cold-Water
Distribution Systems(3/8"- 2"):

ASTMD2846-99el.

Chlorinated Poly (VinylCh]oride)(CPVQPIasticPipe(SDR-PR)(l/4"- 12"):

ASTMF442-99.

Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Pipe, Schedules 40
and 80(1/4"- 12"):

ASTMF441-02.

Chlorinated Poly (Vinyl Chloride) (CPVC)Plastic Pipe Fittings, Schedule
80; Socket-type (1/4"- 8"):

ASTMF439-02el.

Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Pipe Fittings, Schedule 80,
Threaded (1/4"- 6"):

ASTMF437-99.

Polyethylene (PE) Pressure Pipe and Tubing for Water Service (1/2"- 3"):

AWWAC901-02.

200 6 National Standard Plumbing Code-Ilhtstrated

Polyethylene (PE) Plastic Pipe (SDR-PR) Based on Controlled Outside
Diameter(l/2"-6"):

ASTMD3035-03a.

Polyethylene (PE) Plastic Pipe (SIDR -PR) Based on Controlled Inside Diameter
(1/2"- 6"):

ASTMD2239-03.

Reserved

Polyethylene (PE) Plastic Pipe, Schedules 40 and 80, Based on Outside
Diameter (1/2"- 12"):

ASTMD2447-03.

Polyethylene (PE) Plastic Tubing (1/2"- 2"):

ASTM D2737-03.

Butt Heat Fusion Polyethylene (PE) Plastic Fittings for Polyethylene (PE)
Plastic Pipe and Tubing (1/2"- 48"):

ASTM D326 1-03.

Plastic Insert Fittings for Polyethylene (PE) Plastic Pipe ( 1/2"- 4"):

ASTMD2609-02.

Corrugated Polyethylene (PE) Tubing and Fittings (3"- 6"):

ASTMF405-97.

Smoothwall Polyethylene (PE) Pipe for use in Drainage and Waste Disposal
Absorption Fields (3"- 6"):

ASTM F81 0-01.

Styrene-Rubber(SR) Plastic Drain Pipe and Fittings (2"- 6"):

ASTM D2852-95(R2002).

Reserved

Fiberglass Pressure Pipe (1" and larger):

AWWAC950-01.

Fiberglass (GFR) Sewer and Industrial Pressure Pipe (8" and larger):

ASTM D3754-04.

Fiberglass (GFR) Sewer Pipe ( 8 " and 1 arger):

ASTM D3262-04.

Fiberglass (GFR)Non-Pressure Pipe Fittings (8" and larger):

ASTMD3840-01.

Reserved

Vitrified Clay Pipe, Extra Strength, Standard Strength, and Perforated
(3" and larger):

ASTMC700-02.

Concrete Drain Tile (4" and larger):

ASTM C4 12-03.

Concrete Sewer, Storm Drain, and Culvert Pipe; non-reinforced (4" and larger):

ASTM CI 4-03.

Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe (1 2" and larger):

ASTM C76-05.

Perforated Concrete Pipe (4" and larger):

ASTMC444-03.

Crosslinked Polyethylene (PEX) Plastic Hot- and Cold-Water Distribution
Systems:

ASTMF877-05.

Crosslinked Polyethylene (PEX) Tubing:

ASTM F876-04.

Metal Insert Fittings Utilizing a Copper Crimp Ring for SDR9 Crosslinked
Polyethylene (PEX) Tubing:

ASTM Fl 807-04.

Cold Expansion Fittings with PEX Reinforcing Rings for Use with Cross-linked
Polyethylene (PEX) Tu bing :

ASTM Fl 960-05.

Crosslinked Polyethylene/ Aluminum/Crosslinked Polyethylene (PEX- AL-PEX)
Composite Pressure Pipe (3/8"- 1 "):

ASTM Fl 281-03.

Polyethylene/Aluminum/Polyethylene (PE-AL-PE) Composite PressurePipe
(3/8"- 1")

ASTM Fl 282-03.

Metal Insert Fittings for Crosslinked Polyethylene/ Aluminum/Crosslinked
Polyethylene (PEX-AL-PEX) and Polyethylene/Aluminum/Polyethylene
CompositePressurePipe(PE-AL-PE):

ASTM Fl 974-04.

Polyethylene/Aluminum/Polyethylene (PE-AL-PE) Composite Pressure Pipe
Systems(l/4"- 1"):

CSAB137.9-02.

Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene (PEX-AL-PEX)
Composite PressurePipe Systems (1/4"- 1"):

CSAB137.10-02.

Polyethylene (PE) Plastic Pipe (SDR-PR) Based Upon OutsideDiameter:

ASTM F714-05. (See Tables3.4,
3.5, & 3. 7 for minimum SDR values
for trenchless replacement systems.)

2006 National Standard Plumbiiw Code- Illustrated

Reserved

Stainless Steel Clamps for Securing SDR 9 Cross-linked Polyethylene (PEX)
Tubing to Metal Insert Fittings:

ASTMF 2098-04.

CrossIinkedPolyethylene/Aluminum/Crosslinked Polyethylene
(PEX-AL- PEX) Tubing ODControled SDR-9(l/2"- 1 "):

ASTMF2262-04.

Pressure-rated Composite Pipe and Fittings for Elevated Temperature Service,
Classes I and 2 (1 6mm - 50mm)

ASTMF1335-04.

1\ . PIPK JOliN 1 S. JOINING MAI EKIALS, COI 'PI. INKS, CASKFXS* ' A > * 5*^3

PipeThreads, Tapered, General Purpose:

ASME Bl.20.1-1983 (R2001).

Liquid and Paste Fluxes for Soldering Applications of Copper and Copper
Alloy Tube:

ASTMB813-00(el).

Solder Metal:

ASTMB32-04.

BrazingFilterMetal:

AWS A5.8/A5.8M-2004.

Pig Lead:

ASTMB29-03.

Grooved and Shouldered Joints (Split Couplings):

A WWA C606-04.

Flexible Transition Couplings for Underground Piping Systems:

ASTM CI 173-02.

Rubber Sheet Gaskets:

ASTMD1330-04.

Rubber Gasket Joints for Ductile- Iron and Gray-Iron Pressure Pipe and Fittings:

ASTMC1173-02;AWWAC1I1/
A21. 11-00.

Rubber Gaskets for Cast-Iron Soil Pipe and Fittings:

ASTMC564-03a.

Couplings for Hubless Cast-iron Soil Pipe and Fittings:

FM 1 680-89, CISPI 31 0-04, ASTM
C1277-04; ASTM C1540-04.

Compression Joints for Vitrified Clay Pipe and Fittings:

ASTMC425-04.

Rubber Gasket Joints in Circular Concrete Sewer and Culvert Pipe:

ASTMC44303.

Elastomeric Seals (gaskets) for Push-On Joints in Plastic Pipe:

ASTMF477-02el.

Flexible Elastomeric Seals for Plastic Pressure Pipe:

ASTM D3139-98 (R2005).

FlexibleElastomeric Seals for Plastic Drain and Sewer Pipe:

ASTM D3212-96a (R2003)el.

Socket-end IPS PVC Pipe Joints:

ASTM D2672-96a (JR2003).

Primers for Solvent Cement Joints in PVC Plastic Pipe and Fittings:

ASTM F656-02.

Solvent Cement for Acrylonilrile-Butadiene-Styrene (ABS) Plastic Pipe
and Fittings:

ASTM D2235-04.

Solvent Cements forPoly (Vinyl Chloride) (PVC) Plastic Piping Systems:

ASTMD2564-04.

Solvent Cements for Transition Joints Between Acrylonitrile-Butadiene-Styrene
(ABS)and Poly (Vinyl Chloride)(PVC)Non-PressurePipingComponents:

ASTM D3 138-04.

Solvent Cements for Chlorinated Poly (Vinyl Chloride) (CPVC)PIastic Pipe
and Fittings:

ASTMF493-04.

Solvent Cements for Styrene-Rubber (SR) Plastic Pipe and Fittings:

ASTM D3122-95(R2002).

Mechanical Couplings for Drain, Waste and Vent Pipe and Sewer Pipe:

CSA B602-99 (R2002).

Fittings for Connecting Water Closets to the Sanitary Drainage System:

ASME Al 12.4.3-1 999 (R2004).

Standard Specification forMechanical Couplings Using Thermoplastic
Elastomeric (TPE) Gaskets for JoiningDrain, Waste and Vent (DWV), Sewer,
Sanitary and Storm Plumbing Systems for Above and Below Ground Use:

ASTM CI 46 1-02.

Non-Reinforced Extruded Tee Connections for Piping Applications:

ASTM F201 4-00.

Standard Specification for Heavy Duty Shielded Couplings Joining Hubless
Cast Iron Pipe and Fittings |

ATSM CI 540-04.

2006 National Standard Plumbing Code- Illustrated

".V.i\>.- .. ■/->": .../-"■ "■■■■" V. PLUMBING FIXTURES :!' ..: .'"" : *-: - •• -

Bathtubs, Plastic:

IAPMO Zl 24.1.2-2005; CSA
B45.5 of CSA B4S Series-02 with
B45S1-04 Supplement

Ceramic Plumbing Fixtures, Non-Vitreous:

ASME A112.19.9M-199I (R2002);
CSA B45.1 of CSA B45 Series-02
with B45S1-04 Supplement.

Drains for Prefabricated and Precast Showers:

ASME Al 12.18.2-2005/CSA

Bl 25.2-05

Drinking Fountains and Water Coolers, Self Contained, Mechanically
Refrigerated:

ARI 1010-2002,
UL399 Edition 6-1993.

Enameled Cast-Iron Plumbing Fixtures:

ASMEA1 1 2.1 9.1M -1994 (R2004);
CSA B45.2 of CSA B45 Series-02
with B45S1 -04 Supplement

Enameled Steel Plumbing Fixtures:

ASMEAH2.19.4M-1994(R2004);
CSA B45.3 of CSA B45 Series-02
with B45S1 -04 Supplement

Floor and Trench Drains:

ASME Al 12.63-2001.

Lavatories, Plastic:

ANSIZ124.3-1995; CSAB45.5of
CSA B45 Series-02 with B45S1-
04 Supplement

Roof, Deck, and Balcony Drains:

ANSIA1 12.6.4-2003.

Shower Receptors and Shower Stalls, Plastic:

IAPMO Zl 24.1.2-2005; CSA
B45.5 of CSA B45 Series-02 with
B45S1-04 Supplement

]]

Stainless Steel Plumbing Fixtures (residential design):

ASMEAI12.193M-1994(R2004);
CSA B45.4 of CSA B45 Series-02
with B45S1-04 Supplement

Vitreous ChinaPlumbing Fixtures:

ASME Al 1 2.1 9.2-2003, CSA
B45.1 of CSA B45 Series-02 with
B45S1-04 Supplement

Water Closet Bowls and Tanks, Plastic:

ANSI Zl 24.4- 1996; ASME
Al 12.19.2-2003; CSAB45.5of
CSA B45 Series-02 with B45S1-
04 Supplement

Whirlpool Bathtub Appliances:

ASME Al 12.1 9.7M-1 995.

Reserved

Urinals, Plastic:

ANSlZ124.9-1994;CSAB45.5of
CSA B45 Series-02 with B45S1-
04 Supplement

Fabricated Stainless Steel Security Water Closets:

IAPMO PS-61 -92; CSAB45.4of
CSA B45 Series-02 with B45S1-
04 Supplement

Hydraulic Performance of Water Closets and Urinals:

ASME All 2. 19.2-2003.

Wall Mounted and Pedestal Mounted Adjustable and Pivoting Lavatory
and Sink Carrier Systems:

ASME All 2.1 9.12-2000 (R2004)

2006 National Standard Plumbing Code-Ulttstraied

Plastic Sinks:

ANSI Z124.6-1997; CSA B45.5of
CSA B45 Series-02 with B45S1-
04 Supplement

Prefabricated Spa Shells:

ANSI Zl 24.7-97.

Plastic BathtubLiners:

ANSI Zl 24.8-90.

Bathtubs and Whirlpool Bathtubs with Pressure Sealed Doors:

ASMEA112.19.15-2001.

Emergency Showers and Eyewash Stations:

ISEAZ358.1-2004.

Six Liter Water Closets Equipped with a Dual Flushing Device:

ASME Al 1 2.1 9.1 4-2001 with
Supplement 1-2003

Electro-hydraulic Water Closets:

ASME All 2.1 9.13-2002

Enameled and Epoxy Coated Cast Iron and PVC Plastic Sanitary Floor Sinks

ASME Al 12.6.7-2001

VI. FLUMB1NG FIXTURE TRIM ? ; **^?.'

Anti-siphon Fill Valves (Ballcocks) for Gravity Water Closet Flush Tanks:

ASSE 1002-1999, CSA B125.3-05

Individual Thermostatic, Pressure Balancing, and Combination Pressure
Balancing and Thermostatic Control Valves for Individual FixtureFittings

ASSE1016-2005,ASME

Al 12.18.1 -2005/CSA B125.1-05

Divertors for Plumbing Faucets with Hose Spray, Anti-Siphon Type,
Residential Application:

ASSE 1025-1978; CSA B125-01.

PlumbingFixture Fittings:

ASMEA112.18.1-2005/CSA
B125.1-05

Flushometers (Pressurized Flushing Devices):

ASSE 1037-1990, CSA B125.3-05

Laboratory Faucet Vacuum Breakers:

ASSE 1035-2002.

Showers, Hand Held:

ASMEA112.18.1-2005/
CSAB125.1-05

Supports for Off- The-FloorPlumbing Fixtures:

ASMEA112.6.1M-1997(R2002).

Trim for Water Closet Bowls, Tanks, and Urinals (dimensional standards):

ASME All 2.1 9.5- 1999,
CSA Bl 25.3-05

Flexible Water Connectors:

ASME Al 12.18.6-2003.

Water Closet Seats, Plastic:

ANSI Z124.5- 1997.

Whirlpool Suction Fittings:

ASME Al 12.19.8-1987 (Rl 996).

Performance Requirements for Backflow Protection Devices and Systems in
PlumbingFixture Fittings:

ASME Al 12.18.1-2005/CSA
B125.1-05

Temperature Actuated Flow Reduction (TAFR) Valves for Individual Fixture
Fittings:

ASSE 1062-1997.

Individual Pressure Balancing In-Line Valves for Individual Fixture Fittings:

ASSE 1066-1997.

Deck Mounted Bath/Shower Transfer Valves with Integral Backflow Protection:

ASME All 2.1 8.7-1999 (R2004)

Plumbing Fixture Waste Fittings:

ASMEA112.18.2-2005/CSA
Bl 25.2-05

Thermoplastic Accessible and Replaceable Plastic Tube and Tubular
Fittings; for Waste Connections (1-1/4", 1-1/2"):

ASTMF409-02.

Dual Flush Devices for Water Closets:

ASME Al 12.19.10-2003

Plastic Fittings for Connecting Water Closets to the Sanitary Drainage
System :

ASME A 11 2.4.3- 1 999 (R2004)

2006 National Standard Plumbing Code-Illustrated

Wall Mounted and Pedestal Mounted, Adjustable and Pivoting Lavatory
and Sink Carrier Systems:

ASME A 1 1 2.3.4 - 2000 (R2004)

Water Closet Personal Hygiene Devices:

ASME Al 12.4.2 -2003

Safety Vacuum Release Systems (SVRS) for Spa and Hot Tub Suction Systems:

ASME All 2.4.2 -2002

\ II. PLl'MBINC APPI IA\C * S

Clothes Washers;

AHAMHLW-1 -2002, ASSE 1007-
1986

Dishwashing Machines, Commercial:

UL 921 Edition 5-1996,
ASSE 1004-1990

Dishwashers, Household:

UL 749 Edition 7-1 997, AH AM
DW-1-2004, ASSE 1006-1986

Food Waste Grinder Units, Commercial:

ASSE 1009-1990.

Food Waste Disposal Units, Household:

AH AM FWD -1-2005, ASSE

1 008-1 986, UL 430 Edition 6-2004

Hot Water Dispensers:

ASSE 1023-1979.

Water heater, Gas, Volume I, Storage Type, 75,000 BTUH Input or less

ANSI Z21.10.1-2004/CSA 4.1-04

Water Heaters, Gas, Volume III, Storage Type with Input above 75,000 gjUH
Circulating and Instantaneous, Electric Storage Tank Type

ANSI Z21 .10.3-2004/CSA 4.3-04

Water Heaters, Household Electric Storage Tank Type:

UL 174 Edition 11-2004

Water Heaters, Instantaneous. Electric, Point-of-use:

UL 499 Edition 12-1 997.

Water Heaters, Oil-Fired Storage Type:

UL 732 Edition 5-1 995.

Water Heater Relief Valve Drain Tubes:

ASME Al 12.4.1-1993 (R2002).

Water Softeners (CationExchange):

NSF 44-2004

Reverse Osmosis Drinking Water Treatment Systems:

NSF 58-2004

Macerating Toilet Systems and Related Components:

ASME Al 12.3.4 -2000 (R2004),
CSA B45.9 of CSA B45 Series-02
with B45S1 -04 Supplement

''„..- Vra^^yAi^SAK^A^FjtlRTENANCJES - , -" s ..." ; .. ' r'-^'-v/

Backwater Valves:

ASME Al 12.1 4.1-2003, CSA
Bl 81. 1-02 of CSA B1800 series
(ABS), CSA B181 .2-02 of CSA
Bl 800 series (PVC)

Anti-siphon Fill Valves (Ballcocks) for Gravity Water Closet Flush Tanks:

ASME 1002-1999; CSA B125-01

Bronze Gate, Globe, Angle and Check Valves:

MSS SP-80-2003.

Check Valves, Swing, Cast-iron:

MSSSP-71-1997.

Cleanouts:

ASMEA1 12.36.2M-199HR2002).

Drain Valves, Water Heater:

ASSE 1005-1999.

Flushometers (Pressurized Flushing Devices):

ASSE 1037-1990; CSA Bl 25-01.

Gate Valves, Cast-iron, 1 25# and 250#:

MSSSP-70-1998.

Gate Valves, Iron Body (3" and larger):

AWWAC500-02.

Water Pressure Reducing Valves:

ASSE 1003-2001.

2006 iX'aiioiia! Standard Plumbing Cade-Illustrated

Relief Valves and Automatic Gas Shut-off Devices for Hot Water Supply

ANSI Z21.22-1999/CSA4.4-M99,

ANSI Z21 .22A-2000/CSA 4.4 A-
2000, ANSI Z21 .22B-2001/CSA
4.4B-2001.

Temperature Actuated Mixing Valves for Hot Water Distributions Systems:

ASSE 1017-2003; CSA B125.3-05

Trap Seal Primer Valves, Potable Water Supplied:

ASSE 1018-2002.

Water Hammer Arrestors:

ASSE 1010-2004, PDIWH201-
1992.

Pre-Pressurized Potable Water Tanks (forthermal expansion):

IAPMO PS 88-2002.

Reserved

Ball Valves, Threaded, Socket- Welding. Solder Joints, Grooved, And Flared
Ends:

MSSSP-110(1996).

Water Temperature Limiting Devices

ASSE 1070-2004.

Wall Hydrants, Vacuum Breaker Type, Freeze Resistant, Automatic Draining:

ASSE 1019-2004.

Trap Seal Primer Devices - Drainage and Electronic Types:

ASSE 1044-2002.

Wall Hydrants, Dual Check Backflow Type, Freeze Resistant:

ASSE 1053-2004.

Pressure Balancing In-LineMixing Valves for Individual Fixture Fittings:

ASSE 1066-1997.

Automatic Temperature Control Mixing Valves:

ASSE 1069-2005.

;«• ' V* • .ix! . • backfjlow^reVentionbbvjces :> -V.

Air Gap Dram for Domestic Dishwashers:

ASSE 1021-2001.

Backflow Preventers with Intermediate Atmospheric Vent:

ASSE 1012-2002.

Detector Assembly, Double Check Type:

ASSE 1048-2005.

Detector Assembly, Reduced Pressure Type:

ASSE 1047-2005.

Double Check Valve Assembly:

ASSE 1015-2005.

Dual Check Valve Type Backflow Preventer:

ASSE 1024-2004.

Dual Check Valve for Carbonated Beverage Dispensers:

ASSE 1032-2004.

Reduced Pressure Principle Backflow Preventer:

ASSE 1013-2005.

Vacuum Breaker, Atmospheric (Pipe-Applied):

ASSE 1001-2002.

Vacuum Breaker, Hose Connection:

ASSE 1011-2004.

Vacuum Breaker, Laboratory Faucet:

ASSE 1035-2002.

Vacuum Breaker, Pressure:

ASSE 1020-2004.

Reserved

Hose Connection Backflow Preventers:

ASSE 1052-2004.

Vacuum Breakers, Spill-Resistant:

ASSE 1056-2002.

Air Gaps in Plumbing Systems:

ASMEA1 12.1.2-2004.

Performance Requirements for Backflow Protection Devices and Systems in
PlumbingFixture Fittings:

ASMEA1 12.18.3-2002;
CSA Bl 25-01.

Air Gap Fittings for Use with Plumbing Fixtures, Appliances and
Appurtenances:

ASMEA112.1 3-2000.

Outdoor Enclosures for Backflow Prevention Assemblies:

ASSE 1060-1996.

Backflow Prevention Devices for Hand-Held Showers:

ASSE 1014-2005

Backflow Preventers for (Carbonated) Beverage Dispensing Equipment:

ASSE 1022-2003

7006 National Standard Plumbing Code-//lusiraled

X MISrMJ OlbOCS

Copper Flashing (sheet):

ASTM B370-03.

Lead Flashing (sheet):

ASTM B749-03.

Pipe Hangers and Supports (materials, design, manufacture):

MSS SP-58-2002.

Poly (Vinyl Chloride) (PVC) Plasti c Flexible Concealed Water-Contaminant
Membrane:

ASTM D4551-96(R2001).

Shower Pan Liner (PVCPlastic Sheeting):

ASTM D455 1-96 (R2001).

Chlorinated Polyethylene (CPE) Sheeting for Concealed Water-Containment
Membrane:

ASTM D4068-01.

Shower Pan Liner(Plastic Sheeting):

ASTMD4068-0L

Grease Interceptors:

ASMEA1 12.143-2000.

Floor Affixed Supports for Off-the-FloorPlumbingFixtures for Public Use:

ASMEA1 12.6.1 Ml 997 (R2002).

Framing Affixed Supports for Off-the-Floor Plumbing Fixtures:

ASME All 2.6.2-2001 (R2004).

Plastics Piping System Components and Related Materials:

NSF 1 4-2004 with Addendum 1 .0

Drinking Water System Components-Health Effects:

NSF 61 -2004 with Addendum 1.0

Grease Recovery Devices (GRD):

ASME AI 12.14.4-2001.

Non Sewered Waste Disposal Systems Minimum Requirements

ANSI Z4.3 - 1 987 (Rl 995).

Chemical Dispensing Systems

ASSE 1055-1997.

XI. RECOMMENDED PRACTICES AND STANDARDS FOR QUALIFICATIONS,

INSTALLATION, AND TESTING

Installation of Ductile-Iron Water Mains and Appurtenances;

AWWAC600-99.

Installing Vitrified Clay Pipe Lines:

ASTMC12-04eL

Safe Handling of Solvent Cements, Primers and Cleaners Used for Joining
Thermoplastic Pipe and Fittings:

ASTMF402-05.

Practice for Making Solvent-Cemented Joints with Poly(VinyI Chloride) (PVC)
Pipe and Fitting:

ASTM D2855-96(R2002).

Underground Installation of Thermoplastic Pressure Pipe (up to 6"):

ASTM D2774-04.

Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity
Flow Applications:

ASTMD2321-04el.

Recommended Practice for Installation of Thermoplastic Pipe and Corrugated
Tubing in Septic Tank Leach Fields:

ASTM F481-97(R2002).

Plastic Fitting Patterns; Drain, Waste, and Vent (DWV):

ASTMD3311-02el.

Selection and Application of Pipe Hangers and Supports:

MSS SP-69-2003.

Fabrication and Installation Standards for Pipe Hangers and Supports:

MSS SP-89-2003.

Field Test Procedures for Backflow Prevention Devices:

ASSE 5010-2004.

Professional Qualification Standard for Backflow Prevention Assembly
Testers, Repairers, and Surveyors:

ASSE Series 5000-2004

Practice for Heat- Joining Polyolefin Pipe and Fittings:

ASTM D2657-03.

Practice for Electrofusion Joining Polylefin Pipe and Fittings:

ASTM Fl 290-98 (R2004).

Making Capillary Joints by Soldering of Copper and Copper Alloy Tube and
Fittings:

ASTM B828-02.

100

2006 National Standard Plumbing Code-Illustrated

Standard for Health Care Facilities:

NFPA 99-2005.

Gas and Vacuum Systems:

NFPA99C-2005.

Professional Qualification Standards for Medical Gas Systems Installers,
Inspectors, Verifiers, Maintenance Personnel, and Instructors:

ASSE Series 6000-2004.

Installation Procedures for Stainless Steel Drainage Systems:

ASMEA1 123.1-1993

NOTES FOR TABLE 3.1.3

(1 ) See application sections of Chapter 3 for limitations on specific piping materials.

(2) Pipe sizes contained in parentheses ( ) are provided for general information on the scope of the referenced standard and are
not intended to limit use.

(3) Alloy shall be marked on pipe and fittings.

2006 National Standard Plumbing Code- Illustrated

101

Table 3.4 - ^jej^^s for

HOT WATER DISTRU3U

TIC

POTABLE WATER

(1)(2)(3)(6)(7)

CQLD WATER DISTRJBUTK

WATER SERVICE PIPING

ABS Plastic Pipe, SDR (ASTM D2282)

%fh

ABS Plastic Pipe, Schedule 40 or 80 (ASTM D1527)

-X

Brass Pipe (ASTM B43)

Copper Pipe (ASTM B42)

Copper Water Tube, Type K or L (ASTM B88)

Copper Water Tube, Type M (ASTM B88)

CPVC Plastic Pipe, Schedule 40, 80 (ASTM F441)

CPVC Plastic Pipe, SDR (ASTM F442)

CPVC Plastic Water Distribution Systems (ASTM D2846)

Ductile Iron Pipe, Cement-lined (ASTM A377, ANSI/A WWA C151/A21.51)

||1*^§

Fiberglass Pressure Pipe (A WWA C950)

A i X

Galvanized Steel Pipe (ASTM A53)

-i.

High-Density Polyethylene (HDPE) Plastic Pipe, SDR-1 1 (ASTM F714)

Reserved

Jv *" '■

PE Plastic Pipe, Schedule 40, 80 (ASTM D2447, rated 160 psi minimum at 73 deg F)

fAi.

PE Plastic Pipe, SDR (ASTM D3035)

*3fc

PE Plastic Pipe, S1DR (ASTM D2239, rated 160 psi minimum at 73 deg F)

PE Plastic Tube (ASTM D2737)

PE Plastic Pressure Pipe and Tubing (AWWA C901, rated 160 psi minimum at 73 deg F)

l x

PE-AL-PE Composite Pressure Pipe (ASTM F1282, CSA B137.9 pipe with ASTM F1974
metal insert fittings)

PEX-AL-PEX Composite Pressure Pipe (ASTM F1281, CSA B137.10 pipe with ASTM
F1974 metal insert Fittings)

Pressure-Rated Composite Pipe and Fittings for Elevated Temperature Service: (ASTM
F1335)

Crosslinked Polyethylene (PEX) Tubing (ASTM F876)

ASTM F877 PEX Plastic Water Distribution Systems (ASTM F876 tubing with ASTM
F1960 cold expansion fittings or ASTM F1807 metal insert fittings with ASTM F2098
clamps)

Crosslinked Polyethylene/Aluminum/Polyethylene (PEX-AL-PEX) Tubing, OD
Controlled, SDR 9 (ASTM F2262)

PVC Plastic Pressure Pipe, (AWWA C900)

iot.

*X?

PVC Plastic Pipe, Schedule 40,80,120 (ASTM D1785)

-Xj

PVC Plastic Pipe, SDR (ASTM D2241)

•x

Approved
Not Approved

A
"X

NOTES FOR TABLE 3 4

(l)Piping for potable water shall be water pressure rated for not less than 160 psi at 73°F.

(2)Piping for hot and cold water distribution shall be water pressure rated for not less than 100 psi at I SOT and 160 psi at 73°F.

(3)Plastic piping materials shall comply with NSF ]4,

(4) Minimum SDR-1 1 for trenchless water service replacement systems

(5) Permitted for trenchless replacement of underground portions of piping within buildings.

(6) See Table 3.4.2 for plastic water service piping

(7) See Table 3 A3 for plastic hot and cold water distribution piping.

102

?006 National Standard Plumbing Code Illustrated

Table 3.4.2
PLASTIC WATER SERVICE PIPE (2)

(water pressure rated not less than 1 60 psi at 73 deg F)

•

MATERIAL

COMPOSITION

DIMENSIONS

JOINTS

PIPE SIZE

ABS(ASTMD1527)

ABS 1208

Schedule 40

not threaded

up thru 1 "

Schedule 80

threaded

none

Schedule 80

not threaded

up thru 2"

ABS 1210

Schedule 40

not threaded

up thru 1-1/2"

Schedule 80

threaded

up thru 1 "

Schedule 80

not threaded

up thru 4"

ABS 1316

Schedule 40

not threaded

up thru 5"

Schedule 80

threaded

up thru 2-1/2"

Schedule 80

not threaded

up thru 12"

ABS 21 12

Schedule 40

not threaded

up thru 3"

Schedule 80

threaded

up thru 1-1/4"

Schedule 80

not threaded

up thru 6"

ABS (ASTM D2282)

ABS 1316

SDR 2 1 and lower
(1)

not threaded

all sizes

ABS2112

SDR 1 7 and lower
(1)

not threaded

all sizes

ABS 1210

SDR 13.5

not threaded

all sizes

ABS 1208

none

PVC(ASTMDI785)

PVC 1 1 20

Schedule 40

not threaded

up thru 8"

Schedule 80

threaded

up thru 4"

Schedule 80

not threaded

up thru 24"

Schedule 120

threaded

up thru 12"

Schedule 120

not threaded

up thru 12"

PVC 1220

Schedule 40

not threaded

up thru 8"

Schedule 80

threaded

up thru 4"

Schedule 80

not threaded

up thru 24"

Schedule 120

threaded

up thru 12"

Schedule 120

not threaded

up thru 12"

PVC 2120

Schedule 40

not threaded

up thru 8"

Schedule 80

threaded

up thru 4"

Schedule 80

not threaded

up thru 24"

Schedule 120

threaded

up thru 12"

Schedule i20

not threaded

up thru 12"

PVC 21 16

Schedule 40

not threaded

up thru 5"

Schedule 80

threaded

up thru 2"

Schedule 80

not threaded

up thru 24"

Schedule 120

threaded

up thru 5"

Schedule 120

not threaded

up thru 12"

PVC2112

Schedule 40

not threaded

up thru 3"

Schedule 80

threaded

up thru 1-1/4"

Schedule 80

not threaded

up thru 6"

Schedule 120

threaded

up thru 1-1/2"

Schedule 120

not threaded

up thru 12"

•

7006 National Standard Plumbing Code Illustrated

103

Table 3.4.2 (Continued)

PVC 21 10

Schedule 40

not threaded

up thru 1-1/2"

Schedule 80

threaded

up thru 1 "

Schedule 80

not threaded

up thru 4"

Schedule 120

threaded

up thru 1 "

Schedule 120

not threaded

up thru 12"

PVC(ASTMD2241)

PVC 1120

SDR 26 or lower (1)

not threaded

all sizes

PVC 1220

SDR 26 or lower (1)

not threaded

all sizes

PVC 2120

SDR 26 or lower (1)

not threaded

all sizes

PVC 21 16

SDR 21 or lower (1)

not threaded

all sizes

PVC 21 12

SDR 17 or lower (1)

not threaded

all sizes

PVC 21 10

SDR 13.5 or lower
(D

not threaded

all sizes

PVC (AWWA C900)

12454-A, -B

DR14

not threaded

up thru 1 2"

CPVC (ASTM D2846)

CPVC 4120

SDR 11

not threaded

all sizes

CPVC(ASTMF441)

CPVC 4120

Schedule 40

not threaded

up thru 1 2"

CPVC 41 20

Schedule 80

threaded

up thru 4"

CPVC 4120

Schedule 80

not threaded

up thru 1 6"

CPVC (ASTM F442)

CPVC 4120

SDR 26 or lower (1)

not threaded

up thru 12"

PE (ASTM D2239)

PE 3408

SIDR9orlower(l)

not threaded

all sizes

PE 3306

SlDR7orlower(l)

not threaded

all sizes

PE 3406

SlDR7orlower(l)

not threaded

all sizes

PE 2306

SIDR7orlower(l)

not threaded

all sizes

PE 2406

SIDR7orlower(l)

not threaded

all sizes

PE 2305

SIDR 5.3

not threaded

all sizes

PE 1404

none

PE (ASTM D2447)

PE 2306

Schedule 40

not threaded

1/2"

Schedule 80

not threaded

up thru I -1/4"

PE 2406

Schedule 40

not threaded

1/2"

Schedule 80

not threaded

up thru 1-1/4"

PE 3306

Schedule 40

not threaded

1/2"

Schedule 80

not threaded

up thru 1-1/4"

PE 3406

Schedule 40

not threaded

1/2"

Schedule 80

not threaded

up thru 1-1/4"

PE 2305

Schedule 40

not threaded

none

Schedule 80

not threaded

up thru 3/4"

PE 1404

Schedule 40

not threaded

none

Schedule 80

not threaded

1/2"

PE (ASTM D2737)

PE 2305

SDR 7.3

not threaded

all sizes

PE 2306

SDR 9

not threaded

all sizes

PE 2406

SDR 9

not threaded

all sizes

PE 3306

SDR 9

not threaded

all sizes

PE 3406

SDR 9

not threaded

all sizes

PE 3408

SDR 11

not threaded

all sizes

104

7006 National Standard Plumbing Code-Illustrated

Table

3.4.2 (Continued)

PE (ASTM D3035)

PE 3408

SDR 11 or lower (1)

not threaded

all sizes

PE 2406

SDR 7

not threaded

all sizes

PR 1404

none

PE(ASTMF714)

SDR 11

not threaded

all sizes

PE(AWWAC90I)

PE 2406

IDR7

not threaded

up thru 3'
160)

(pressure class

PE 3406

IDR7

not threaded

up thru 3'
160)

(pressure class

PE 3408

IDR9

not threaded

up thru 3'
160)

(pressure class

PE 2406

DR9

not threaded

up thru 3'
160)

(pressure class

PE 3406

DR9

not threaded

up thru 3'
160)

(pressure class

PE 3408

DR 11

not threaded

up thru 3'
160)

(pressure class

PE-AL-PE (ASTM Fl 282)

PE-AL-PE

ASTM F 1282

not threaded

all sizes

PEX (ASTM F876)

PEX 1006

SDR 9

not threaded

all sizes

PEX (ASTM F877)

PEX

SDR 9

not threaded

all sizes

PEX-AL-PEX (ASTM
F1281)

PEX-AL-PEX

ASTM Fl 281

not threaded

all sizes

PEX-AL-PEX (ASTM
F2262)

PEX-AL-PEX

SDR 9

not threaded

all sizes

Composite (ASTM Fl 335)

PE-AL-PE

ASTM Fl 335

compression

all sizes

Composite (ASTM Fl 335)

PEX-AL-PE

ASTM Fl 335

compression

all sizes

NOTES

(1) Lower SDR numbers have heavier wall thicknesses and higher pressure ratings.

(2) Refer also to the manufacturer's recommendations, instructions and limitations.

Table 3.4.3
PLASTIC HOT AND COLD WATER DISTRIBUTION PIPING (1)

(water pressure rated for not less than 100 psi at 1 80 deg F and 160 psi at 73 deg F)

MATERIAL

COMPOSITION

DIMENSIONS

JOINTS

PIPE SIZES

CPVC (ASTM D2846)

CPVC 4 120

SDR 11

not threaded

all sizes

CPVC(ASTMF44I)

CPVC 4120

Schedule 40

not threaded

up thru 2"

Schedule 80

threaded

up thru 2

Schedule 80

not threaded

up thru 2"

CPVC (ASTM F442)

CPVC 4 120

SDR 11 &13.5

not threaded

all sizes

PEX (ASTM F876)

PEX 1006

SDR 9

not threaded

all sizes

PEX (ASTM F877)

PEX

SDR 9

not threaded

all sizes

PE-AL-PE (ASTM Fl 282)

PE-AL-PE

ASTM F1282

not threaded

all size

PEX-AL-PEX (ASTM F2262)

PEX-AL-PEX

SDR 9

not threaded

all sizes

PEX-AL-PEX (ASTM F128I)

PEX-AL-PEX

ASTM Fl 281

not threaded

all sizes

Composite Pipe (ASTM F1335)

PE-AL-PE

ASTM D1335

compression

all sizes

Composite Pipe (ASTM F1335)

PEX-AL-PE

ASTM D1335

compression

all sizes

•

NOTES

( 1 ) Refer also to the manufacturer's recommendations, instructions and limitations.

2006 National Standard Plumbing Code-Illustrated

105

Table 3.5 - MATERIALS FOR
SANITARY WASTE & DRAIN

(1)(2)(3)

ABOVEGROUND WITHIN BUILDINGS

UNDERGROUND WITHIN BUILDINGS

SEWERS OUTSIDE OF BUILDINGS

ABS Pipe and Fittings, Schedule 40 DWV (ASTM D2661)

ABS Pipe - Cellular Core (ASTM F628) and DWV Fittings

ABS Sewer Pipe and Fittings (for sewers outside of buildings) (ASTM D2751) (I)

ABS and PVC Composite Sewer Pipe (ASTM D2680)

Brass Pipe (ASTM B43)

-X

-X*

Cast-Iron Soil Pipe and Fittings - Bell and Spigot (ASTM A74)

Cast-iron Soil Pipe and Fittings - Hubless (CISPI 301, ASTM A888)

Cellular Core PVC Sewer and Drain Pipe (ASTM F891)

"X,

9
10
11
12

14
~\5

Cellular Core PVC Sewer and Drain Pipe (ASTM F891) (4)

isH

Cellular Core PVC DWV Pipe, IPS Schedule 40 (ASTM F891 )

Concrete Drain Pipe. Nonres'nforced (ASTM CI 4)

F^gl

Concrete Drain Pipe, Reinforced (ASTM C76)

Copper Pipe (ASTM B42)

Copper Tube - DWV (ASTM B306) and Copper Drainage Fittings (ASME B 16.23)

Copper Water Tube - K,L,M (ASTM B88) and Copper Drainage Fittings (ASME Bl 6.23)

Fiberglass Sewer and Pressure Pipe (ASTM D3754) and Fiberglass Non-Pressure Pipe Fittings
(ASTM D3840)

17
18
19
20

"IT

"23~
24
25

~2b

Galvanized Steel Pipe (ASTM A53) and-Cast-Iron Drainage Fittings (ASME B16.12)

</»«•

High-Density Polyethylene (HDPE) Plastic Pipe (ASTM F714) (6)

im..

t v

PVC Pipe and Fittings, DWV (ASTM D2665)

PVC Schedule 40 Drainage and DWV Fabricated Fittings (ASTM F1866)

PVC Sewer Pipe (PS-46) and Fittings (ASTM F789) (2)

PVC Sewer Pipe (PSM) and Fittings (ASTM D3034) (2)

, w VSt

Stainless Steel DWV Systems - Type 3 1 6L (ASME Al 12.3.1) (5)

Stainless Steel DWV Systems - Type 304 (ASME Al 12.3.1) (5)

Vitrified Clay Pipe - Standard Strength (ASTM C700)

Vitrified Clay Pipe - Extra Strength (ASTM C700)

Approved
Not Approved

NOTES FOR TABLE 3. 5

(1) Plastic drain, waste, and vent piping classified by standard dimensionn ratio shall be SDR 26 or heavier (lower SDR number).

(2) Plastic sewer pipe classified by pipe stiffness shall be PS-46 or stiffer (higher PS number).

(3) Piping shall be applied within the limits of its listed standard and the manufacturer's recommendations.

(4) PS- 1 00 pipe or sti ffer (h igher PS number).

(5) Alloy shall be marked on pipe and fittings
(6)Minimum SDR-1 7 fortrenchless sewer replacement systems.

106

2006 National Standard Plumbing Code-Illustrated

•

Table 3.6 - MATERIALS
FOR VENT PIPING (1)

ABOVEGROUND

UNDERGROUND

ABS Pipe and Fittings, Schedule 40 DWV (ASTM D2661)

ABS Pipe - Cellular Core (ASTM F628) and DWV Fittings

Brass Pipe (ASTMB43)

Cast-iron Soil Pipe and Fittings -Bell and Spigot (ASTM A74)

Cast-Iron Soil Pipe and Fittings -Hubless (CISP1 301, ASTM A888)

Cellular Core PVC DWV Pipe, IPS Schedule 40 (ASTM F891)

Copper Pipe (ASTM B42)

Copper Tube - DWV (ASTM B306) and Copper Drainage Fittings (ASME Bl 6.23)

Copper Tube - K, L, M (ASTM B88) and Copper Drainage Fittings (ASME B 16.23)

Galvanized Steel Pipe (ASTM A53) and Cast-iron Drainage Fittings (ASME B16.12)

PVC Pipe and Fittings, DWV (ASTM D2665)

PVC Schedule 40 Drainage and DWV Fabricated Fittings (ASTM F 1866)

Stainless Steel DWV Systems-Type 3 1 6L (ASME Al 12.3,1) (2)

Stainless Steel DWV Systems-Type 304 (ASME A 112.3.1) (2)

3.25 M OD PVC Pipe and Fittings, DWV (ASTM D2949)

Vitrified Clay Pipe- Extra Strength (ASTM C700)

Approved
Not Approved

NOTES FOR TABLE 3.6

( 1 ) Piping shall be applied within the limits of its listed standards and the manufacturer's
recommendations.

(2) Alloy shall be marked on pipe and fittings.

•

2006 National Standard Plumbing Code-Illustrated

107

Table 3.7 - jyiATERIALS
FOR STORM DRAINAGE

(1)

ABOVEGROUND WITHIN BUILDINGS

UNDERGROUND within BU i LDING

SEWERS OUTSIDE OF BUILDING

ABS Pipe and Fittings, Schedule 40 DWV (ASTM D266 1 )

ABS Pipe - Cellular Core (ASTM F628) and DWV Fittings

ABS Sewer Pipe and Fittings (ASTM D2751) (2) (3)

ABS and PVC Composite Sewer Pipe (ASTM D2680)

Brass Pipe (ASTM B43)

*75

Cast-iron Soil Pipe and Fittings - Bell and Spigot (ASTM A74)

Cast-Iron Soil Pipe and Fittings - Hubless (CISPI 301 , ASTM A888)

Cellular Core PVC Sewer and Drain Pipe (ASTM F891) (3)

Cellular Core PVC Sewer and Drain Pipe (ASTM F891) (4)

:■$*,

4 x

Cellular Core PVC DWV Pipe, IPS Schedule 40 (ASTM F891)

Concrete Drain Pipe, Nonreinforced (ASTM C14)

*X-.

Concrete Drain Pipe, Reinforced (ASTM C76)

'$£*>

Copper Pipe (ASTM B42)

Copper Tube - DWV (ASTM B306) and Copper Drainage Fittings (ASME B16.23)

Copper Tube - K,L,M (ASTM B88) and Copper Drainage Fittings (ASME B 16.23)

Galvanized Steel Pipe (ASTM A53) and Cast-Iron Drainage Fittings (ASME B16.12)

PE- High-Density Polyethylene (HDPE) Plastic Pipe, SDR- 17, (ASTM F714)(6)

X X

PVC Pipe and Fittings, DWV (ASTM D2665)

PVC Schedule 40 Drainage and DWV Fabricated Fitting (ASTM Fl 866)

PVC Sewer Pipe (PS-46) and Fittings (ASTM F789)

rx^x-

PVC Sewer Pipe (PSM) and Fittings (ASTM D3034) (2) (3)

'/*f!

;'x

22
23
24

Stainless Steel DWV Systems-Type 31 6L (ASME A112.3.1)(5)

Stainless Steel DWV Systems-Type 304 (ASME Al 12.3.1 )(5)

Vitrified Clay Pipe - Standard Strength (ASTM C700)

Vitrified Clay Pipe - Extra Strength (ASTM C700)

Approved
Not Approved

NOTES FOR TABLE 3 .7
(l)Piping shall be applied within the limits of its listed standards and the manufacturer's recommendations.

(2) SDR 35 pipe or heavier (lower SDR number).

(3) PS-46 pipe or stiffer (higher PS number).
(4)PS-100pipeorstiffer(higherPSNurnber).

(5) Alloy shall be marked on pipe and fittings

(6) Minimum SDR- 1 7 for trenchless sewer systems.

108

1006 National Standard Plumbing Code-IUustraied

Table 3.8 - MATERIALS FOR FOUNDATION DRAINS AND SUB-SOIL DRAINAGE

Clay Drain Tile (ASTM C498)

Concrete Drain Tile (ASTM C412)

Perforated Concrete Pipe (ASTM C444)

Corrugated Polyethylene Tube (ASTM F405)

SR Plastic Drain Pipe and Fittings, Perforated (ASTM D2852)

PVC Sewer Pipe and Fittings, Perforated (ASTM D2729)

Stainless Steel DWV Systems - Type 316L (ASME A 1 12.3.1)

Vitrified Clay Pipe, Perforated, Standard and Extra Strength (ASTM C700)

Approved

2006 National Standard Plumbing Code-Illustrated

109

Blank Page

110 2006 National Standard Plumbing Code-Illustrated

Chapter 4

Joints and Connections

4.1 GENERAL REQUIREMENTS

4.1.1 Tightness

Joints and connections in the plumbing system shall be gas tight and watertight for the pressure required by
test, with the exceptions of those portions of perforated or open joint piping that are installed for the purpose
of collecting and conveying ground or seepage water to the underground storm drains.

Comment: Perforated and open-joint piping is also used for the piping in absorption trenches for private
sewage disposal systems. See Section J 6.9.5.

4.1.2 Joint Standards

a. Pipe and tube shall be cut 90° or perpendicular to the pipe center lines.

b. The inside diameter of pipe and tube ends shall be reamed, filed, or smoothed to size of bore and all
chips removed. All burrs on the outside of the pipe and butt ends shall be removed before the installation.

c. Pipe and tube shall engage into fittings the full manufacturer's design depth of the fitting socket.

d. Male pipe threads shall be made of sufficient length to ensure the proper engagement.

e. Pipe shall not extend into a fitting or other pipe to such a depth that it will impede or restrict the design
flow.

f. Joints made by bonding, welding, brazing, solvent cementing, soldering, burning, fusion or mechanical
means shall be free from grease or other substances not specifically required to achieve a satisfactory joint.

g. Pipe sealing or lubricating compound required for threaded pipe joints shall be applied to the male pipe
end onlv and shall be insoluable and nontoxic.

Comment: For industry standards for the various joining methods, refer to Table 3. 1.3 - Part IV Pipe
Joints, Joining Materials, Couplings, Gaskets.

4.1.3 Expansion Joints

Mechanical type expansion joints requiring or permitting adjustment shall be accessible for adjustment and/or
replacement.

4.1.4 Increasers and Reducers

Where different sizes of pipes or pipes and fittings are to be connected, increaser and reducer.fittings or
bushings shall be used. (See Section 2.4.3)

2006 National Standard Plunihitis CoJe-Ulu.vntiecl

111

4.2 TYPES OF JOINTS FOR PIPING MATERIALS

4,2.1 Caulked

4.2,1.1 Cast-Iron Soil Pipe

Lead caulked joints for cast-iron hub and spigot soil pipe shall be firmly packed with oa kum or hemp and filled
with molten lead not less than 1 inch deep and not to extend more than 1/8 inch below the rim of the hub.
No paint, varnish, or other coatings shall be permitted on the jointing material until after the joint has been
tested and approved. Lead shall be run in one pouring and shall be caulked tight. See Figure 4.2.1.1

OAKUM

LEAD - ONE CONTINUOUS POUR
SET WITH CAULKING IRONS

CAST IRON
HUB END

CAST IRON
SPIGOT END

Figure 4.2.1.1
A LEAD CAULKED JOINT IN CAST IRON SOIL PIPE

4.2.1.2 Cast-Iron Water Pipe

Lead caulked joints for cast-iron ball and spigot water pipe shall be firmly packed with clean dry jute, or treated
paper rope packing. The remaining space in the hub shall be filled with molten lead according to the following
schedule:

Pipe Size Depth of Lead

Up to 20 inches 2- 1/4 inches

24,30. 36 inches 2- 1/2 inches

Larger than 36 inches 3 inches

Lead shall be run in one pouring and shall be caulked tight. See Figure 4.2.1.2

APPROVED SEALING MATERIAL

LEAD - ONE CONTINUOUS POUR
SET WITH CAULKING IRONS

CAST IRON

WATER PIPE

HUB END

CAST IRON
WATER PIPE
SPIGOT END

Figure 4.2.1.2
A LEAD CAULKED JOINT IN IRON WATER PIPE

2006 Nuiioiuii Standard Plumbing Codc-tllmimted

4.2.2 Threaded

The threads in taper threaded pipe joints shall conform to ASME B. 1 .20. 1 . See Figure 4.2.2

TAPERED PIPE THREADS (ASME B1.20.1)

REAMED CHAMFER

Figure 4,2.2
A THREADED PIPE JOINT

4.2.3 Wiped

Joints in lead pipe or fittings, or between lead pipe or fittings and brass or copper pipe, ferrules, solder nipples,
or traps, shall be full wiped joints. Wiped joints shall have an exposed surface on each side of a joint not less
than 3/4 inch and at least as thick as the material being jointed. Wail or floor flange lead-wiped joints shall be
made by using a lead ring or flange placed behind the joints at wall or floor. Joints between lead pipe and
cast-iron, steel, or wrought iron shall be made by means of a caulking ferrule, soldering nipple, or bushing.
See Figure 4.2.3

WIPED LEAD SOLDER

LEAD PIPE ■

^^^^ jgfefe

COPPER PIPE

Figure 4.2.3
A WIPED JOINT ON LEAD PIPE

4.2.4 Soldered

a. Soldered joints in copper water piping shall be made using wrought pressure fittings complying with ASME
B 1 6.22, cast pressure fittings complying with ASME B 1 6. 1 8. or cast copper alloy flanges complying with ASME
B16.24.

NOTE: Short-cup brazing fittings complying with ASME B 1 6.50 and bearing the mark "BZ" shall not be used
where joints are soldered.

b. Soldered joints in copper drain and vent piping shall be made with wrought drainage fittings complying with
ASME B 16.29 or cast drainage fittings complying with ASME B 16.23.

c. Soldered joints shall be made in accordance with ASTM B828.

d. Solder shall comply with ASTM B32. Flux shall comply with ASTM B8 1 3.

e. Solder for joints in potable water piping shall contain not more than 0.2% lead. See Figure 4.2.4

2006 National Standard Plumbing Catie-liiustraied

113

Comment: The limit on lead in solder filler metal is to reduce the level of lead in drinking water in
accordance with the EPA Safe Drinking Water Act

COUPLING

. soLDER FILLER METAL

kv, sx ^ -v-v -v-N v\ w \\. vTw, ^ v,^ >CT / ip

COPPER TUBE

>#####/*

«A HJvl * -vv ^ '\ V> V> Sx * Vis ^

COPPER TUBE

Figure 4.2.4
A SOLDERED JOINT

4.2.5 Flared

Flared joints for copper water tube shall be made with fittings complying with ASME B 1 6.26. The tube shall
be reamed and then expanded with an approved flaring tool. See Figure 4.2.5

FLARE NUT

WRENCH FLAT

ANNEALED COPPER TUBING

NOTES:

1. A long flare nut is shown. Short flare nuts are permissible where vibration is not a factor.

Figure 4.2.5
A FLAKED COPPER JOINT

4.2.6 Mechanically Crimped (Pressed) Joints

a. Copper fittings for water supply and distribution, designed for mechanically crimped (pressed) connections to
ASTM B88 hard drawn copper water tube, shall include an O-ring gasket complying with NSF 6 1 for potable water.
EXCEPTION: Mechanically crimped (pressed) joints shall be permitted with annealed copper water tube when such
use is included in the fitting manufacturer's technical data and installation instructions.

b. The fittings shall comply with the material and sizing requirements of ASME B 1 6.22 (wrought copper or copper
alloy fittings) or ASME B 1 6. 1 8 (cast copper alloy fittings).

c. During installation, the tube end shall be deburred and depth-marked to penn it visual verification of full insertion
of the tube into the fitting socket.

d. The joint shall be crimped (pressed) using a tool approved by the manufacturer of the fitting.

e. flie joints shall be rated by the manufacturer for not less than 200 psig at 1 80 deg F.

f. The fittings shall be permitted to be installed in concealed locations.

114

2006 National Simulant Plumbing Code-fltusiinti'd

4.2.7 Push-on Joints

a. Copper fittings for water supply and distribution, designed for manual push-on connections to ASTM B88
hard drawn copper tubing, shall include corrosion-resistant gripping fingers and an O-ring gasket complying
with NSF 61 for potable water.

EXCEPTION: Push-on fittings shall be permitted to be used with annealed copper water tube and OD sized
CPVC and PEX tubing if such use is included in the fitting manufacturer's technical data and installation
instructions.

b. The fittings shall comply with the material and sizing requirements of ASME B 16.22 (wrought copper or
copper alloy fittings) or ASME B 1 6. 1 8 (cast copper alloy fittings).

c. During installation, the rube end shall be deburred and depth-marked to permit visual verification of full
insertion of the tube into the fitting socket.

d. The fittings shall be rated by their manufacturer for not less than 200 psig at 1 80 deg F.

e. The fittings shall be permitted to be installed in concealed locations.

4.2.8 Brazed

4.2.8.1 General

a.~Brazed joints in copper tubing shall be made in accordance with accepted industry practice. See Appendix

L for an accepted practice for general plumbing.

b. Brazed joints in medical gas and vacuum piping shall be made in accordance with NFPA 99 or NFPA 99C.

4.2.8.2 Fittings

a. Fittings in copper tubing with brazed joints shall be wrought solder joint fittings complying with ASME
B 1 6.22 or short-cup brazing fittings complying with ASME B 1 6.50. Short-cup brazed joint fittings shall be
clearly marked by the manufacturer to differentiate them from solder-joint fittings and avoid their being used
in piping with soldered joints.

b. Fittings for medical gas and vacuum piping shall be as required by NFPA 99 or NFPA 99C.

4.2.8.3 Mechanically Formed Tee Branches

a. Mechanically formed tee branches shall be permitted in copper tubing in water distribution systems. The
branch connections shall be formed with appropriate tools and joined by brazing. The branch tube end shall
be notched and dimpled with two sets of double dimples. The first dimples shall act as depth stops to prevent
the branch tube from being inserted beyond the depth of the branch collar. The second dimples shall be
1/4" above the first dimples and provide a visual means of verifying that the branch connection has been
properly fitted. The dimples in the branch tube shall be in line with the run of the main. The joints shall be
brazed in accordance with Section 4.2.8.1 and ASTM F2014.

b. Mechanically former tee branches shall not be permitted in drainage piping.

4.2.9 Cement Mortar

a. Where permitted as outlined in Sec. 2.4.4, cement mortar joints shall be made in the following manner: 1 .
A layer of jute or hemp shall be inserted into the annular joint space and packed tightly to prevent mortar from
entering the interior of the pipe or fitting.

2. Not more than 25 percent of the annular space shall be used for jute or hemp.

3. The remaining space shall be filled in one continuous operation with a thoroughly mixed mortar composed
of one part cement and two pans sand, with only sufficient water to make the mixture workable by hand.

4. Additional mortar of the same composition shall then be applied to form a one to one slope with the barrel
ofthepipe.

2006 National Standard Plunibms Code-Illustrated

IIS

5. The bell or hub of the pipe shall be left exposed for inspection.

6. When necessary, the interior of the pipe shall be swabbed to remove any mortar or other material that
may have found its way into such pipe.

Comment: Cement mortar joints have been virtually eliminated by the use of alternate joining methods
and materials.

4.2.10 Burned Lead (Welded)

Burned (welded) joints shall be made in such a manner that the two or more sections to be joined shall be
uniformly fused together into one continuous piece. The thickness of the weld shall be at least as thick as the
lead being joined.

Comment: The added welding material must be of the same composition as the lead pipe being joined.

4.2.11 Mechanical (Flexible or Slip Joints
4.2.11.1 Stainless Steei DWV Systems

a. Joints in stainless steel DWV systems shall be made with an elastomeric o-ring of amaterial that is suitable
for the intended service.

b. Joints between stainless steel drainage systems and other piping materials shall be made with an approved
adapter coupling.

4.2.11.2 Cast-Iron Soil Pipe

a. Hublesspipe: Joints forhubless cast-iron soil pipe and fittings shall be made with an approved elastomeric
sealing sleeve and corrosion resisting clamping device or shall be made using a rigid unshielded TPE coupling
with center stop installed per Section 4.3.8d.

b. Huband Spigot: Joints for hub and spigot cast-iron soil pipe and fittings, designed for use with a compressed
gasket, may be made using a compatible compression gasket that is compressed when the spigot is inserted
into the hub of the pipe.

See Figures 4.2.1 1.2- A and -B

ELASTOMERIC
GASKET

SHIELD

CORROSION RESISTANT CLAMP AND SCREWS

SHIELDED COUPLING

Figure 4.2.1 1.2-A
A SHIELDED COUPLING ON HUBLESS CAST IRON SOIL PIPE

JI6

1006 National Standard Plumbing Code-tUuSlmted

•

Figure 4.2.1 1.2-B
A CAST IRON HUBBED JOINT WITH A COMPRESSION GASKET

4.2.113 Cast-iron Water Pipe

Mechanical joints in cast-iron water pipe shall be made with a flanged collar, a rubber ring gasket, and the
approved number of securing bolts. See Figure 4.2.1 1 J

•

GASKET

TEE HEAD BOLT

\\\\s.\\\v\s\\^\Yi:v\\x\\\\>/\\ \'\\\\\\\\\n\Tn

Figure 4.2.11.3
A MECHANICAL JOINT ON IRON WATER PIPE

•

2006 National Standard Plumbing Code-lliitstruicd

117

4.2.11.4 Clay Pipe

Joints In piping and/or fittings shall be made using flexible compression joints. See Figure 4.2.11.4

RUBBER COUPLING

CORROSION RESISTANT
CLAMPS AND SCREWS

CLAY PIPE-
PLAIN END

Figure 4.2.11.4
AN UNSHIELDED COUPLING ON PLAIN END CLAY PIPE

4.2.11.5 Concrete pipe

Flexible joints between lengths of concrete pipe may be made using approved compression type joints or
elastomeric materials born on the spigot end and in the bell (or hub) end of the pipe. See Figure 4.2.11.5

•

■ O-RiNG

CONCRETE PIPE
BELL END

CONCRETE PIPE
SPIGOT END

Figure 4.2.11.5
A JOINT IN BELL AND SPIGOT CONCRETE PIPE

4.2.11.6 Elastomeric Sleeves

Mechanical joints on drainage pipes below ground shall be made with an elastomeric seal conforming to ASTM
D3212, CSA B602 or ASTM CI 173. Joints shall be installed in accordance with the manufacturer's
instructions.

118

2006 National Slu/uhnl Plumbing Codc-lllustruied

4.2.12 Reserved

4.2.13 Reserved

4.2.14 Plastic

Joints in plastic piping shall be made with approved fittings by either solvent cement or heat joined connecti ons ;
approved couplings consisting of elastomeric sleeves and corrosion resisting metal screw clamps; approved
insert fittings; approved mechanical fittings; or threaded joints according to approve standards. PVC solvent
cemented joints shall use an approved primer appropriate for the material used. An approved purple colored
primer and solvent cement not purple in color shall be used in joining PVC pipe and fittings. An approved color
primer not orange in color and solvent cement orange in color or a single step solvent cement that is yellow
in color and is third party certified as conforming to ASTM F493 shall be used in joining 1/2 inch through 2
inch in diameter CP VC pipe and fittings that are manufactured in accordance with ASTM D2846.
EXCEPTION: Primer shall be used for CPVC pipe and fittings where recommended by the manufacturer(s)
of the pipe and fittings. See Figures 4.2.1 4- A through-F

k\\\ss\\\sss^

PRIMER (IF REQUIRED) AND SOLVENT
CEMENT APPLIED TO PIPE ENDS
AND FITTING SOCKET

^W^VvXW^

WIPED BEAD

Figure 4.2. 14- A
A SOLVENT CEMENT JOINT IN PLASTIC DWV OR WATER PIPING

ELASTOMERIC GASKET JOINT FOR UNDERGROUND
BUILDING DRAINS OR SEWERS

Figure 4.2.I4-B
AN ELASTOMERIC GASKET JOINT FOR UNDERGROUND PLASTIC DWV PIPING

•

2006 National Siondurd Plumbing Code-Illustrated

119

ELASTOMERIC
GASKET

PLASTIC DWV PIPE

SHIELD

CORROSION RESISTANT CLAMPING SCREWS

PLASTIC DWV PIPE

CORROSION RESISTANT CLAMPS

Figure 4.2J4-C
A SHIELDED COUPLING ON PLASTIC JWV PIPING

PLASTIC PIPE WITH SOCKET (BELL) END

PRIMER (IF REQUIRED) AND SOLVENT CEMENT
ON PIPE END AND INSIDE OF SOCKET

Figure 4.2.14-D
A SOLVENT CEMENT JOINT IN SOCKET (BELL) END PLASTIC PRESSURE PIPE

CORROSION RESISTING CLAMP DEVICE
OR CRIMP RING ASSEMBLY

nni\\\\vv.\\\\\\s

PLASTIC TUBING

_J II Rn ^ ^ Ti ^ Tii y ^ ^ ^ ^ ^ ^

\ INSERT FITTING

NOTES

1. Some manufacturers recommend two damps on each side of the fitting for additional joint strength.

Figure 4.2.14-E
AN INSERT FITTING JOINT IN PLASTIC TUBING

120

2006 National Standard Plumbing Code-f liusrratt-J

HEAT FUSED AREAS

Figure 4.2.14-F
A HEAT FUSED JOINT IN PLASTIC WATER PIPING

4.2.15 Slip

Slip joints shall be made using approved packing or gasket material, or approved ground joint brass compres-
sion rings. Ground joint brass connections that allow adjustment-of tubing but provide a rigid joint when made
up, shall not be considered as slip joints. See Figure 4.2. 15- A and-B

WASHER

COMPRESSION SLIP NUT

METAL OR PLASTIC TUBING

NOTES:

1. Straight tubular joints having washers are slip joints and require access. Refer to the definition of
"accessible"

Figure 4.2. 15- A
A SLIP JOINT IN DRAIN TUBING

2006 Notional Standard Plumbing Code— Illustrated

121

BRASS COMPRESSION RING
OR FERRULE

LOCKNUT

METAL OR PLASTIC TUBING

NOTES:

1. When a compression joint does not permit free movement when assembled, it is not considered to
be a slip joint and does not need to be accessible. Refer to the definition of "accessible".

Figure 4.2.1 5-B
A COMPRESSION JOINT IN DRAIN TUBING

4.2.16 Expansion

Expansion joints shall be of approved type and its material shall conform with the type of piping in which it is
installed. See Figures 4.2.16-A,-B, and-C

Comment: Expansion joints must to be accessible for adjustment or replacement. Refer to the definition

of" accessible".

SOLVENT CEMENT

O-RINGS

SOLVENT CEMENT

Figure 4.2.1 6- A
AN EXPANSION JOINT FOR PLASTIC DWV PIPING

122

2006 National Slum/an! Plumbing Cade-lihalraled

Figure 4.2.1 6-B
A MECHANICAL EXPANSION JOINT IN PRESSURE PIPING

NLET

ADJUSTABLE EXPANSION SLEEVE
WRENCH GRIP

WING NUT AND BOLT
(3 AT 120° APART}
PACKING GLAND

PACKING

BODY

OUTLET

Figure 4.2.16-C
AN EXPANSION JOINT FOR ROOF DRAINS

4.2.17 Split Couplings

a. Split couplings consisting of two or more parts and a compression gasket, designed for use with grooved
or plain end pipe and fittings, shall be permitted to be used for water service piping, hot and cold domestic
water piping, storm water conductors and leaders, and sump pump discharge piping. The completejoint
assembly shall be suitable for the intended use and comply with a standard listed in Table 3.1.3.
b. Galvanized steel pipe or other interior coated pipe shall not be joined using rolled grooves.
See Figure 4.2.17

2006 National Standard Plumbing Ct/Je-Illitsiraiccl

123

HOUSING
GROOVED PIPE

GASKET

GROOVED PIPE

Figure 4,2.17
A GROOVED PIPE JOINT

4.2.18 Butt Fusion

A STM.F7 14 high-density polyethylene (HDPE) pipe and ASTM D3261 fittings shall be joined by butt fusion
in accordance with ASTM D2657.

4.2.1 9 Bending

Changes in direction in copper water tube shall be permitted to be made by the use of factorv or field bends. Field
bends shaH be ma de i„ accordance w.th Table 4.2. 19. Bends shail be made oniy w,,h bending ea^pmem and

procedures intended for that purpose. Hard drawn tubing shall not be bent with tubing benders intended for only
annealed (soft) tube. All bends shall be smooth and free from buckling, cracks, and other evidence of mechanical
damage.

Table 4.2.19: BEND]

LNG COPPER TUBE

Nominal Tube Size -in.

Tube Type

Temper

Min. Bend Radius, in.

1/4 inch

K,L

Annealed (soft)

3/4"

3/8 inch

K,L

Annealed (soft)

1-1/2"

3/8 inch

K,L,M

Drawn (hard)

1-3/4"

1/2 inch

K.L

Annealed (soft)

2-1/4"

1/2 inch

K,L,M

Drawn (hard)

2-1/2"

3/4 inch

K,L

Annealed (soft)

3/4 inch

Drawn (hard)

1 inch

K,L

Annealed (soft)

1-1/4 inches

Annealed (soft)

4.3 TYPES OF JOINTS BETWEEN DIFFERENT PIPING MATERIALS

4.3.1 Vitrified Clay to Other Material

Joints between vitrified clay and other piping materials shall be made with an approved joint. See Figures
4.3.1 -A and-B

124

1006 Nuiiotuil Standard Plumbing Codc-lllttstrated

•

COMPRESSION
JOINT SEALER

NOTES:

1. The rubber rings must be sized to adapt to the different outside diameters (O.D.) of the different
piping materials being joined.

2. There are hundreds of different adapters available for joining different materials, different pipe sizes,
and different wall thickness, as well as clay pipe from different manufacturers.

Figure 4.3. J -A
A RUBBER RING TRANSITION JOINT TO V1TR | FIED CLAY PIPE

SHIELD

ELASTOMERIC

CORROSION RESISTANT CLAMPING SCREWS

CORROSION RESISTANT CLAMPS

NOTES:

1. Externally clamped couplings (shielded and unshielded) are a common way of making transition
connections from vitrified clay pipe to other piping materials. Various sized gaskets are available to
adapt to the different outside diameters (O.D.) of the piping materials being joined.

Figure 4.3. LB

AN EXTERNALLY CLAMPED TRANSITION COUPLING JOINT

TO VITRIFIED CLAY PIPE

4.3.2 Reserved

4.3.3 Reserved

1006 National Standard Plumbing Code— Illustrated

125

4.3,4 Threaded Pipe to Cast-iron

Joints between steel or brass and cast-iron pipe shall be either caulked or threaded or shall be made with
approved adapter fittings. See Figure 4.3.4

OAKUM

LEAD

THREADED STEEL OR BRASS PIPE

CAST IRON PIPE

Figure 4.3.4
A THREADED PIPE TO CAST IRON ADAPTER FITTING

4.3.5 Lead to Cast-iron or Steel

Joints between lead and cast-iron or steel pipe shall be made by means of wiped joints to a caulking ferrule,
soldering nipple, bushing, or by means of a mechanical adapter. See Figure 4.3.5

LEAD PIPE

WIPED LEAD

BRASS CAULKING FERRULE

Figure 4.3.5
A WIPED LEAD TRANSITION JOINT

126

2006 Naiiuiuil Standard Plumbing Code-lUusirated

•

4.3.6 Cast-iron to Copper Tube

Joints between cast-iron and copper tube shall be made by using an approved brass or copper caulking ferrule
and by properly soldering the copper rube to the ferrule. See Figure 4.3.6

OAKUM

LEAD

SOLDERED

CAULKING FERRULE

Figure 4.3.6
A CAULKING FERRULE FOR CAST IRON TO SWEAT COPPER TRANSITION

•

.3.7 Copper Tube to Threaded Pipe Joints

a. Joints from copper tube to threaded pipe shall be made as follows:

1 . DWV Systems: with copper or brass threaded adapters.

2. Potable Water Systems and Galvanized Steel Pipe: cast brass threaded adapters, dielectric unions or
flanges (1-1/2" and larger), or dielectric waterway fittings that comply with IAPMO PS 66.

3. To any Non-Ferrous Piping: copper or brass "threaded adapter.

b. The adapter fitting shall be soldered to the tubing by approved methods, and the threaded section as-
sembled with National Pipe Threads — Tapered (NPT).

See Figures 4.3.7 - A and - B

BRASS MALE ADAPTER

THREADED FITTING

Figure 4.3.7-A
A SWEAT COPPER TO THREADED PIPE TRANSITION

2006 National SumJord Plitmhiiis Cotte-lllttsrraied

COPPER SOLDER JOINT
CONNECTOR

STEEL NUT

DIELECTRIC
(INSULATOR )

STEEL BODY

TAPERED PIPE THREADS

COPPER SOLDER JOINT
CONNECTOR

MACHINE
BOLTS

INSULATION
GASKET

INSERT NSF/FDA
LISTED LINING
(INSULATOR)

GROOVED, THREADED
OR PLAIN END

WATERWAY FITTING

ZINC ELECTROPLATED
STEEL CASING

FULLY SEPARATED
DISSIMILLAR METALS

COPPER ADAPTER

TAPERED PIPE THREADS

Figure 4.3.7-B
DIELECTRIC UNION, FLANGE, AND WATERWAY FITTING

43.8 Special Joints and Couplings for Drainage Piping

a. Joints between two different drainage piping materials or between different size piping, of the same or
different material, shall be made using fittings or mechanical couplings that are designed for the specific
application, including adapter fittings, hubless pipe couplings, slip-on couplings, transition couplings, and repair
couplings.

b. Fittings and couplings for use under this Section shall either (1 ) comply with a standard listed in Table
3.1 .3, (2) be listed or labeled by a recognized listing agency, or (3) be approved by the Authority Having
Jurisdiction if such products are not listed or labeled. Installation shall comply with the coupling
manufacturer's instructions and intended use.

c. Shielded couplings shall consist of a flexible elastomeric sealing sleeve, a protecting and supporting
continuous metal shield or shear ring, and metal screw clamping bands. All metal parts shall be corrosion-
resisting. Shielded couplings shall be capable of withstanding a shear test based on a load of 50 pounds per
inch of nominal pipe diameter, and shall be permitted to partially support the pipe being joined when such
installation is recommended by the manufacturer's instructions. Shielded couplings may be installed
aboveground or underground, as intended by the manufacturer.

d. Mechanical unshielded couplings using thermoplastic elastomer gaskets shall consist of a rigid or semi-
rigid sealing sleeve and corrosion-resisting metal screw clamping bands. Mechanical unshielded couplings
using thermoplastic elastomer gaskets shall not be installed where the operating internal or external tempera-

W06 Nutiunid Standard Plumbing Corfe~.lliusiratetl

tures exceed 130°F (54°C) or are below 0°F (-18°C). The pipe shall be supported on both sides of the
coupling within 1 8 inches of the centerhne of the coupling. Mechanical unshielded couplings using thermo-
plastic elastomer gaskets shall be permitted aboveground or underground. Mechanical unshielded couplings
using thermoplastic elastomer gaskets shall not be installed in construction that has a fire rating that restricts
the use of flammable materials or be installed in through penetrations or plenums without additional fire
resistance protection.

e. Flexible unshielded couplings shall consist of an elastomeric sealing sleeve and corrosive-resisting metal
screw clamping bands. The use of flexible unshielded couplings shall be limited to joints in underground sewer,
drain or vent piping.

f. Couplings installed aboveground shall include center stops.
EXCEPTION: Slip-on repair couplings used for repair or rework.

g. The shear tests required under this Section shall be performed in accordance with the shear test
procedures specified under any of the coupling standards listed in Table 3.1.3 that include such tests.

See Figures 4.3.8-A through-D

COUPLING SHIELD

FLEXIBLE ELASTOMERIC
SEALING SLEEVE

CORROSION RESISTANT CLAMPING SCREWS

CORROSION RESISTANT CLAMPS

NOTES:

1 . Shielded couplings can be used aboveground and underground. They can partially support the pipe.
Center stops are required except for repair couplings.

Figure 4.3,8-A
A SHIELDED COUPLING ON DRAINAGE PIPING

RIGID OR SEMI-RIGID SEALING SLEEVE

FLEXIBLE ELASTOMERIC
SEALING SLEEVE

CORROSION RESISTANT CLAMPING SCREWS

WWS/^//r/77777\

CENTER STOP (WHERE REQUIRED)

CORROSION RESISTANT CLAMPS

NOTES:

1. Rigid unshielded couplings can be used aboveground and underground. They cannot support the
pipe. The pipe must be independently supported. Center stops are required except for repair
couplings.

Figure 4.3. 8-B
A RIGID UNSHIELDED COUPLING ON DRAINAGE PIPING

2006 National Standard Plumbing Code-Iflimmied

129

FLEXIBLE ELASTOMERIC ADAPTOR
SEALING SLEEVE

CORROSION RESISTANT CLAMPING SCREWS

DIRECTION OF
DRAINAGE FLOW

•

SHIELDED COUPLING

CORROSION RESISTANT CLAMPS

Figure 4.3.8-C
A TRANSITION CONNECTION USING A SHIELDED COUPLING

FLEXIBLE UNSHIELDED COUPLING

CORROSION RESISTANT
CLAMPING SCREWS

DIRECTION OF
DRAINAGE FLOW

CORROSION RESISTANT CLAMPS

NOTES:

1. Flexible unshielded couplings are limited to underground sewer, drain, and vent piping. Center

stops are required except for repair couplings. The couplings cannot support the pipe. The piping

must be properly backfilled to avoid stresses on the couplings.

Figure 43.8-D
A TRANSITION CONNECTION USING A FLEXIBLE UNSHIELDED COUPLING

4.3.9 ABS or PVC Plastic DWV to Other Material

a. Threaded Joints: ABS or PVC DWV joints when threaded sha!! use the proper male or female threaded
adapter. Use only approved thread tape or lubricant seal or other approved material as recommended by the
manufacturer. Threaded joints shall not be over-tightened. After hand tightening the joint, make a one-half to
one full turn with a strap wrench.

b. Cast-iron Hub Joints. Joints may be made by caulking with lead and oakum or by use of a compression

J 30

7006 National Simulant Plumbing Code-llhimaicil

gasket that is compressed when the plastic pipe is inserted into the cast-iron hub end of the pipe. No adapters
are required for this connection.

c. Cast-iron Spigot Ends, Schedule 40 Steel Pipe or Copper DWV Tube: Joints between these materials and
plastic shall be joined with an approved adapter fitting.

d. The solvent cemented non-pressure joint between dissimilar plastic materials, ABS/PVC building drains and/
or building sewers, shall be made using an ASTM D3 1 38 solvent cement intended for ABS/PVC transition joints.

See Figures 4.3.9-A through-D

THREAD LUBRICANT

MALE ADAPTOR - NPT X SOCKET

PRIMER (IF REQUIRED) AND SOLVENT CEMENT
APPLIED TO PIPE END AND INSIDE OF SOCKET

PLASTIC PIPE

THREADED COUPLING
OR FITTING

Figure 4.3.9-A
A PLASTIC DWV THREADED MAJLE ADAPTER

OAKUM

LEAD

CAST IRON
PIPE

PLASTIC
PIPE

NOTES:

1. Plastic pipe that is lead caulked must be solid plastic. Molten lead will melt cellular core plastic
pipe.

Figure 4.3.9-B
A LEAD CAULKED JOINT FOR PLASTIC DWV TO CAST IRON HUB

2006 National Standard Plumbing Cade-Illustrated

131

COMPRESSION GASKET— ?

PLASTIC
PIPE

Figure 4.3. 9-C
A COMPRESSION GASKETED JOINT FOR PLASTIC DWV TO CAST IRON HUB

PRIMER {IF REQUIRED) AND SOLVENT CEMENT
APPLED TO PIPE END AND INSIDE OF SOCKET

LEAD

CAST IRON PIPE

PLASTIC ADAPTER FITTING

NOTES;

1 . Plastic fittings that are lead caulked musty be solid plastic. Molten lead will melt cellular core pipe
fittings.

Figure 4.3.9-D
A LEAD CAULKED PLASTIC SOCKET JOINT TO CAST IRON PIPE

20% National Standard Ph'.mhuig Codc-fllustmied

4.4 CONNECTIONS BETWEEN DRAINAGE PIPING AND CERTAIN
FIXTURES

a. Connections between drainage piping and floor outlet plumbing fixtures shall be made by means of an
approved flange that is attached to the drainage piping in accordance with the provisions of this chapter. The
floor flange shall be set on and securely anchored to the building structure.

b. Connections between drainage piping and wall hung water closets shall be made by means of an approved
extension nipple or horn adapter.

c. Connections shall be bolted to the flange or carrier using corrosion resisting bolts or screws, or assemblies
recommended by the manufacturer.

4.5 WATERPROOFING OF OPENINGS

a. Joints around vent pipes at the roof shall be made watertight by the use of lead, copper, aluminum, plastic, or
other approved flashing or flashing materials. See Section 1 2.4.7.

b. Exterior wall openings shall be made watertight.

2006 National Standard Plumbing Code-Illustrated 1 33

Blank Page

134 200b National Standard Plumbing Code-lllust rated

•

Chapter 5

Traps, Clean0uts and Backwater Valves

5.1 SEPARATE TRAPS FOR EACH FIXTURE

a. Plumbing fixtures shall be separately trapped by a water seal trap placed as close as possible to the fixture
outlet.

b. The vertical distance from the fixture outlet to the trap weir shall not exceed 24 inches.

c. Fixtures shall not be double- trapped unless a relief vent is provided between the two traps.

d. Fixture designs having integral dual traps within the fixture shall be permitted.
EXCEPTIONS:

( 1 ) Fixtures that have integral traps.

(2) A combination-plumbing fixture may be installed on one trap provided the waste outlets are not more than
30 inches apart.

(3) One trap may be installed for up to three (3) compartment sinks, laundry trays or Javatories that are
immediately adjacent to each other in the same room, and where the trap is centrally located when three such
fixtures are installed.

(4) No clothes washer or laundry tub shall be discharged to a trap serving a kitchen sink.

(5) As otherwise permitted by this Code.
See Figures 5.1-A through-D

LAVATORY

FIXTURE
OUTLET -

FIXTURE
TAILPIECE

MAXIMUM DISTANCE FROM
FIXTURE OUTLET TO TRAP WEIR

24
INCHES

TRAP
WEIR

NOTES:

1. Vertical distances greater than 24" may induce self-siphoning of the trap seal due to the momentum
of the drainage flow.

Figure 5 J - A
THE VERTICAL DISTANCE FROM A FIXTURE OUTLET TO ITS TRAP WEIR

2006 National Simulant Pumbing Codt— Illustrated

135

WATER CLOSET

Figure 5.1 - B
A FIXTURE WITH AN INTEGRAL TRAP

SINK

END OUTLET

I 30"

r" MAXIMUM

NOTES:

1 . Refer to the definitions of "Continuous Waste" and "Combination Fixture'

A CONT.N.O.S^Trl-WnH END OUTLET

SINK

CENTER OUTLET

TRAP

30"

MAXIMUM

NOTES:

1. Refer to the definitions of "Continuous Waste" and "Combination Fixture"

Figure 5.1 - D
A CONTINUOUS WASTE WITH CENTER OUTLET

136

2006 National Standard Pumbin" Codr-Hlitst rated

•

5.2 SIZE OF FIXTURE T&APS

Fixture trap size (nominal diameter) shall be sufficient to drain the fixture rapidly and in no case less than given in
Table 5.2. No trap shall be larger than the drainage pipe into which it discharges. Integral traps shall conform to
appropriate standards.

Comment: A drain pipe that is smaller than the trap to which it is connected could create an obstruction
to flow through the trap.

5.3 GENERAL REQUIREMENTS FOR TRAPS

5.3.1 Design of Traps

Fixture traps shall be self-scouring and shall have no interior partitions except where such traps are integral
with the fixture or where corrosion resistant materials of plastic or glass are used. Solid connections, slip
joints, or couplings may be used on the trap inlet, trap outlet, or within the trap seal. (See Section 7.4.6.) See
Figures 5.3.1 -A through-C. Refer to Sections 4.2.15 and 7.3.7 for slip joints and their required
access.

SOLID CONNECTIONS

FIXTURE TRAP

NOTES;

1. Access is not mandatory for traps with solid connections.

Figure 5.3.1 - A
A FIXTURE TRAP WITH SOLID CONNECTIONS

— ESCUTCHEON

NOTES:

1. Slip joints must be accessible

Figure 5.3.1 - B
A FIXTURE TRAP WITH SLIP JOINTS

2006 National Standard Pumbiti" Coiie-lliustrated

\yi

THREADED
CONNECTION

GROUND JOINT

SLIP JOINT

NOTES:

1. Only the slip joint must be accessible.

Figure 5.3.1 - C
A FIXTURE TRAP WITH THREE DIFFERENT TYPES OF JOINTS

5.3.2 Trap Seals

Each fixture trap shall have a liquid seal of not less than two inches and not more than four inches

EXCEPTIONS:

( 1 ) Interceptors in Chapter 6.

(2) vSpecial conditions such as accessible fixtures,, a deeper seal may be required by the Authority Having
Jurisdiction.

See Figure 5.3.2

INLET-

CROWN WEIR OF TRAP

OUTLET

FLOW

■ TRAP SEAL

DIP OF TRAP -

NOTES:

1 . The minimum trap seal depth of 2" is based on the design criteria for the vent piping. Trap seals
deeper than 4" will tend to trap solids and create a breeding ground for bacteria.

Figure 5.3.2
TRAP SEAL DEPTH

5.3.3 Trap Setting and Protection

Traps shall be set level with respect to their water seals and, where necessary, shall be protected from
freezing. See Figure 5.3.3

IJO

2006 National Slumlord Pwubiwi Codv-Uiiisirated

KITCHEN SINK WITH

FOOD WASTE DISPOSAL UNIT

90° FLANGED TAILPIECE ON
FOOD WASTE DISPOSAL

NOTES

1 . Tilted traps may seif-siphon because of the reduction in the effective depth of the trap seal.

2. Where freeze protection is necessary, thermal insulation atone will not prevent freezing, only delay
it. Traps should be located in heated spaces.

3. Where seasonal facilities are shutdown during the winter, fixture traps can be filled with an anti-
freeze solution that will not damage the traps or drain piping.

Figure 5.3.3
TRAPS MUST BE LEVEL AND PROTECTED FROM FREEZING

•

Table 5.2
MINIMUM SIZE OF NON-INTEGRAL TRAPS

Plumbing Fixture

Trap Size in
inches

Bathtub (with or without overhead shower)

1 Vi

Bidet

1 'A

Clothes washing machine standpipe

Combination sink and wash (laundry) sink with food waste grinder unit

1 Vi (1)

Combination kitchen sink, domestic dishwasher, and food waste grinder

1 Vi

Dental unit or cuspidor

1 %

Dental lavatory

1 Va

Drinking fountain

I %

Dishwasher, commercial

Dishwasher, domestic (non-integral trap)

1 Vz

Floor drain

Food waste grinder, commercial use

Food waste grinder, domestic use

1 } A

Kitchen sink, domestic, with food waste grinder unit

1 Vi

Kitchen sink, domestic

1 Vi

Lavatory, common

1 %

Lavatory (barber shop, beauty parlor or surgeon's)

1 Vi

Lavatory, multiple type (wash fountain or wash sink)

1 Vi

Laundry tray ( 1 or 2 compartments)

1 Vi

Shower stall or shower drain (single shower head)

1 !/ 2

Shower stall or shower drain (multiple shower heads)

Sink (surgeon's)

1 Vz

Sink (flushing rim type, flush valve supplied)

Sink (service type with floor outlet trap standard)

Sink (service type with P trap)

Sink, commercial (pot, scullery, or similar type)

Sink, commercial (with food gnnderunit)

{ 1 ) Separate trap required for wash tray and separate trap required for sink compartment with
food waste grinder.

2006 Natianul Standard Pumbiit* Cudf-IUiixtnued 139

5.3.4 Building Traps

Building traps shall not be installed except where required by the Authority Having jurisdiction. Each building
trap when installed shall be provided with a cleanout and with a relieving vent or fresh air intake on the inlet
side of the trap that shall be at least one-half the diameter of the drain to which it connects. Such relieving
vent or fresh air intake shall be carried above grade and terminate in a screened outlet located outside the
building.

•

Comment: Building traps are no longer installed in modern plumbing systems. They provide a collec-
tion point for solids and other waste that may cause line stoppages. Building traps also prevent the
building vent system from venting the building sewer. The Authority Having Jurisdiction may require
building traps if the sewer gas in the municipal sewage system is particularly corrosive or aggressive and
could damage the drain, waste, and vent piping in the building.

5.3.5 Prohibited Traps

a. The following types of traps shall be prohibited:

1 . Traps that depend upon moving parts to maintain their seal.

2. Bell traps.

3. Crown vented traps.

4. Separate fixture traps that depend on interior partitions for their seal, except if made from plastic, glass
or other corrosion resistant materials.

5. "S" traps, of uniform internal dimension.

6. Drum traps.

b. Hair interceptors, precious metal interceptors and similar appurtenances shall be permitted as required.
See Figure 5.3.5

w=y

BELL TRAP

TRAP IS CROWN VENTED
IF DISTANCE (X) IS WITHIN
TWO PIPE DIAMETERS (Y)

CROWN VENTED TRAP

PARTITION TRAP
{Note 1)

DRUM TRAP

"S" TRAP OF TUBULAR DESIGN!

NOTES:

1. Traps having internal partitions are permitted if constructed of plastic, glass, or other corrosion
resistant material.

Figure 53.5
PROHIBITED TRAPS

140

2006 National Su.nuniid Pumhtng Cudi—llhiXiralt'd

5.3.6 Trap Seal Maintenance

a. Traps that could lose their seal due to evaporation because of infrequent use shall be equipped with a
readily accessible means to replenish the trap seal or a trap primer conforming to ASSE 1018 or ASSE 1044

b. In addition to the priming requirement above, the installation of a sealing component on the fixture drain
outlet to reduce trap seal loss shall be permitted. Sealing devices shall be properly sized for the drain outlet
on which they are installed. They shall permit the fixture to drain completely and shall not leave standing
water or waste on or around the device.

5.4 DRAINAGE PIPE CLEANOUTS

5.4.1 Cleanout Spacing

a. Cleanouts in horizontal drainage lines shall be spaced at intervals not exceeding the following values:

4" pipe size or less: 75 feet
5" size and larger: 1 00 feet

b. The distance referred to in Sections 5.4. 1 a shall include the developed length of the cleanout pipe.
See Figure 5.4.1

•

"X" (See Notes)

PIPE SIZE "D"

NOTES

1 . The maximum spacing "X" for pipes 4" and smaller is 75 feet, including the developed length to the
cleanout opening.

2. The maximum spacing "X" for pipes 5" and larger is 1 00 feet, including the developed length to the
cleanout opening.

3. Manholes may be used for cleanouts in building drains or building sewers {or branches thereof) that
are 8" size or larger. The maximum spacing is 300 feet. Refer to Section 5.4.1 0.

Figure 5.4.1
CLEANOUT SPACING ON HORIZONTAL DRAIN LINES

5.4.2 Building Sewer

Cleanouts, when installed on an underground building sewer, shall be extended vertically to or above the
finished grade level. See Figure 5.4.2

2006 National Standard Pumbittg Codt'-Jltiixirared

141

FINISHED GRADE

BUILDING SEWER

NOTES:

1 . Cleanouts must have flush top covers if located in a walkway or other paved area.

2. The length of the vertical extension to grade must be included in the developed length between
cleanouts.

Figure 5.4.2
A SEWER CLEANOUT EXTENDED TO FINISHED GRADE

5.4.3 Change of Direction

a. Cleanouts shall be installed at changes of direction in drainage piping made with 60°, 70° and 90° fittings.
EXCEPTION; Where there are multiple changes of direction, not more than one cleanout shall be required in

40 feet of run.

b. Cleanouts shall not be required where changes of direction are made with one or more 22 1/2° or 45°
fittings. See Figure 5.4.3

FLOW

•

FLOW

NOTES'

1. A cleanout is not required at Points "B", "C", & "D" if the distance from Point "A" to Point "D" is

less than 40 feet.

Figure 5.4.3

WHERE CLEANOUTS ARE REQUIRED AT CHANGES IN DIRECTION

5.4.4 Cleanouts for Concealed Piping

Cleanouts for concealed piping shall be extended through and terminate flush with the finished wall or floor:
or pits or chases may be left in the wall or floor, provided they are of sufficient size to permit removal of the
cleanout plug and proper cleaning of the system. See Figure 5,4.4

142

2006 National Standard Pumbiitg Cade-Must rated

•

WYE AND
TEST PLUG
ARRANGEMENT

ACCESS PLATE

CLEANOUT TEE
OR TEST TEE

RETAINING SCREW
CLEANOUT COVER

Figure 5.4.4
ACCESS TO CONCEALED GLEANOUTS

5.4.5 Base of Stacks

a. A cleanout shall be provided near the base of each vertical waste or soil stack and located 6 inches
above the flood level rim of the lowest fixture on the lowest floor. If there are no fixtures installed on the
lowest floor, the cleanout shall be installed at the base of the stack.

b. For buildings with a floor slab, a crawl space of less than 1 8 inches, or where a stack cleanout is not
accessible, the cleanout shall be installed in the building drain or building sewer, not more than five feet
outside the building wall .

c. Rain leaders and conductors connected to a building storm sewer shall have a cleanout installed at the
base of the outside leader or inside conductor before it connects to the horizontal drain.

See Figures 5.4.5-A,-B, and-C

CLEANOUT

SANITARY DRAIN OR STORMWATER STACK

FLOOR LINE

3 —

Figure 5.4.5 - A
A CLEANOUT NEAR THE BASE OF A STACK

2006 National Standard Pumbing Cude-lllustrated

143

SOIL OR WASTE
STACK

FOUNDATION WALL

BUILDING DRAIN

CLEANOUT

NOTES:

1. The extension of a cleanout for access in not considered to be a dead end.

Figure 5.4.5 - B
A CLEANOUT EXTENDED TO OUTSIDE OF THE BUILDING FOR ACCESS

RAIN LEADER

ALTERNATE CLEANOUT TEE

•

STu TO BUILDING
STORM SEWER

NOTES:

1 . Cleanouts are required near the base of exterior rain leaders and interior conductors when they
connect to a building storm drain or building storm sewer.

Figure 5.4.5 - C
A CLEANOUT NEAR THE BASE OF A RAIN LEADER

5.4.6 Building Drain and Building Sewer Junctions and the Property Line

a. There shall be a cleanout near the junction of a building drain and building sewer either inside or outside
the building wall.

b. A cleanout shall be placed in the building sanitary sewer and building storm sewer at the property line
and brought to the surface per the requirements of the Authority Having Jurisdiction. and brought to the
surface per the requirements of the Authority Having Jurisdiction.

See Figures 5.4.6 - A and - B

144

2006 Nanmtnl Standard Pumbhig Cade-Illustrated

BUILDING
DRAIN

Figure 5.4.6 - A
A CLEANOUT AT THE JUNCTION OF THE BUILDING DRAIN AND BUILDING SEWER

NOTES:

1. The cleanout and cleanout connection to the sewer required by Section 5.4. 6. b must be within the
property.

Figure 5.4.6 - B
A CLEANOUT AT THE PROPERTY LINE

5.4.7 Direction of Flow

Cleanouts shall be installed so. that the cleanout opens in the direction of the flow of the drainage line or at
right angles thereto. See Figure 5.4.7

2006 Notiontit Sianc/unl Pwnbing Code-llliixtnited

145

TWO-WAY
CLEANOUT

COMBINATION
WYE & 1/8TH BEND

NOTES:

1. Cleanouts must have flush top covers if located in a walkway or other paved area.

Figure 5.4.7
THE FLOW DIRECTION OF CLEANOUTS

5.4.8 Connections to Cleanouts Prohibited

a. Ckanout plug openings in other than drainage pattern fittings shall not be used for the installation of new-
fixtures or floor drains.

b. If a cleanout fitting or cieanout plug opening is removed from a drainage pattern fitting in order to extend
the drain, another cleanout of equal access and capacity shall be provided in the same location.

5.4.9 Cleanout Size

Cleanout size shall conform with Table 5.4.9.

Table 5.4.9
SIZE OF CLEANOUTS

Nominal
Piping Size (inches)

Nominal
Size of Cleanout (inches)

4&6
8&10
]2&15

VU
Vh
2

3
4
6

{ 1 ) See Section 5 .4. J for sizes J 2" or larger Fot building sewers.
(2) See Section 5 .4. 1 3 for cieanout equivalents.

146

2006 Naihmnl Standard Pumbhts Codt—lllusnaltfti

5.4.10 Manholes for Large Pipes

a. Manholes shall be provided as cleanouts for building sewers 12" size and larger. Manholes shall be
provided at every change of size, alignment, direction, grade, or elevation. The distance between manholes
shall not exceed 300 feet,

b. Manholes maybe provided in lieu of cleanouts in underground building sewers, building drains, and
branches thereof, 8" size and larger.

c. Such manholes shall comply with the requirements of Section 5.4. 1 0a,

d. If manholes are installed indoors, they shall have a bolted, gas-tight cover,

e. Manhole construction shall comply with the standards of the Authority Having Jurisdiction.
See Figure 5.4.10

CHANGE OF
DIRECTION

Figure 5.4.10
LOCATION AND SPACING OF MANHOLES

5.4.11 Cleanout Clearances

Cleanouts on 3" or larger pipes shall be so installed that there is a clearance of not less than 1 8" for the
purpose of rodding. Cleanouts smaller than 3 inches shall be so installed that there is a 1 2" clearance for
rodding. See Figure 5.4.1 1-A and-B

2006 National Standard Punihins Code—lllmtraied

147

PIPE SIZE "D"

NOTES:

1 . Minimum clearance "X" is 1 2" if pipe size "D" = 2" or less

2. Minimum clearance "X" is 1 8" if pipe size "D" = 3" or more

Figure 5.4.11 -A
CLEANOUT CLEARANCE ABOVE THE BASE OF A STACK

NOTES:
1.
2.

1
-I

linimum clearance "X" is 12" if pipe size "D" = 2" or iess
linimum clearance "X" is 1 8" if pipe size "D" = 3" or more

Figure 5.4,11 - B
CLEANOUT CLEARANCE AT THE BASE OF A STACK

5.4. J 2 Cleanoutstobe Kept Uncovered

Cleanout plugs shall not be covered with cement, plaster, or any other permanent finishing material. Where it
is necessary to conceal a cleanout plug, a covering plate or access door shall be provided that will permit
ready access to the plug.

5.4.13 Cleanout Equivalent

Where the piping is concealed, a fixture trap or a fixture with integral trap, readily removable without disturb-
ing concealed roughing work, shall be accepted as a cleanout equivalent, provided the opening to be used as a
cleanout opening is the size required by Table 5.4.9.

148

2006 National Shwdarft Pumbing Ctult-j/titsrrati'fl

EXCEPTIONS:

(1) The trap arm of a floor drain with a removable strainer.

(2) Fixtures with readily removable traps not more than one pipe size smaller than the drain served shall
be permitted.

See Figure S.4.13-A and-B

Figure 5.4.13 - A
A WATER CLOSET AS A CLEANOUT EQUIVALENT

r<3

SLIP JOINT

GROUND OR
SLIP JOINT

Figure 5.4.13 - B

2006 Nui'umal Standard Pii'mbing Cade-llluximted

149

5.4.14 Cleanouts for Floor Drains

A cleanout shall be provided immediately downstream from a floor drain whose strainer is not readily remov-
able.

5.5 BACKWATER VALVES

5.5.1 Where Required

a. Fixtures and/or drain inlets subject to backflow and flooding from blocked or restricted public sewers
shall be protected by a backwater valve.

b. Such situations include those where fixtures and/or drains are located above the crown level of the public
sewer at the point of connection thereto, but are below the level of the curb at the point where the building
sewer crosses under the curb at the property line.

c. Backwater valves shall be installed in branches of the drainage system that receive flow only from
fixtures and/or drains subject to backflow from the public sewer.

d. Other portions of the drainage system not subject to such backflow shall drain directly to the public
sewer.

5.5.2 Material Standard and Accessibility

Backwater valves shall conform to ASME Al 12.14.1 and be installed so that their internal working parts are
accessible for periodic cleaning, repair or replacement.

5.5.3 Notice of the Installation of Backwater Valves

When backwater valves are installed in building sanitary drainage systems, a notice shall be posted at the
building water service shutoff valve(s) describing where backwater valves are located.

150 2006 National Standard Pumhiii.e CtHle-llhisirawd

Chapter 6

Liquid Waste Treatment Equipment

6.1 GENERAL

•

6.1.1 Where Required

Interceptors, separators, neutralizes, dilution tanks, or other means shall be provided where required to
prevent liquid wastes containing fats, oils, greases, flammable liquids, sand, solids, acid or alkaline waste,
chemicals, or other harmful substances from entering a building drainage system, a public or private sewer, or
sewage treatment plant or process. See Figure 6.1.1

OUTLET

REMOVABLE
BASKET

GREASE INTERCEPTOR

SOLIDS INTERCEPTOR

GRATE

ACCESS

30VER

s '

INLET

tf^Tv^W.

~=k'

OUTLET

AND INTERCEPTOf

ACCESS
COVER

ADJUSTABLE
OIL —

OIL INTERCEPTOR

Figure 6.1.1
DIFFERENT TYPES OF INTERCEPTORS

6.1.2 Design

The size and type of liquid waste treatment equipment shall be based on the maximum volume and rate of
discharge of the plumbing fixtures and equipment being drained. See Appendix J.

•

6.1.3 Exclusion of OtherLiquid Wastes

Only wastes from fixtures and equipment requiring treatment or separation shall be discharged into treatment
equipment.

2006 National Standard Pumbme Code-Illustrated 1 51

6.1.4 Approval

6.1.4.1 General

The type, size, capacity, design* arrangement, construction, and installation of liquid waste treatment
devices shall be as approved by the Authority Having Jurisdiction.

6.1.4.2 Grease Interceptors and Grease Recovery Devices

Grease interceptors rated for up to 100 gallons per minute shall be certified according to PDI Standard
G101 or ASME Al 12.14.3. Grease recovery devices rated for up to 100 gallons per minute shall be
certified according to ASMEA1 12. 14.4.

6.1.4.3 Mechanical Equipment

Each installation of a manufactured liquid waste treatment device employing pumps, filters, drums,
collection plates, or other mechanical means of operation shall be certified by the manufacturer to
provide effluent meeting the environmental requirements of the sewer or other approved point to which
it discharges.

6.1.5 Venting

Liquid waste treatment equipment shall be so designed that they will not become air-bound if tight covers are
used. Equipment shall be properly vented if loss of its trap seal is possible.

6.1.6 Accessibility

a. Liquid waste treatment equipment shall be so installed that it is accessible for the removal of covers and
the performance of necessary cleaning, servicing and maintenance.

b. The need to use ladders or move bulky objects in order to service interceptors and other liquid waste
treatment equipment shall constitute a violation of accessibility.

6.1.7 Point of Discharge

Connections to sewers or other points of discharge for the effluent from liquid waste treatment equipment
shall be as approved by the Authority Having Jurisdiction.

6.2 GREASE INTERCEPTORS AND GREASE RECOVERY DEVICES (GRID)

6.2.1 Sizes Up to 1 00 GFM

a. Manufactured grease interceptors rated up to 100 gallons per minute shall comply with ASME A 1 12.14.3
and be sized and installed in accordance with the recommendations of PDI Standard G 1 01 - Appendix A and the
manufacturer's instructions. They shall have a grease retention capacity not less than two pounds for each gpm
of rated flow. A flow control device shall be provided to prevent the waste flow (gpm) through the interceptor
from exceeding its rated flow capacity. An air intake shall be provided for the flow control as recommended by
the manufacturer or PDI Standard G101 - Appendix A. See Figure 6.2.1 for a flow control device

b. Grease interceptors that include automatic grease recovery (GRD) shall comply with Section 6.2. 1 .a and
ASME Al 12.14.4.

•

152 2006 National SrumlurJ Pimibini: Coilc-lllusiraieil

PLUNGER FOR
CLEANING ORIFICE

INLET

OUTLET

PACKING GLAND

VENT
CONNECTION

Figure 6.2.1
A FLOW CONTROL DEVICE FOR A GREASE INTERCEPTOR

6.2.2 Fixture Traps

a. Fixtures that discharge into a grease interceptor shall be individually trapped and vented between the
Fixture and the interceptor.

b. When individually trapped and vented fixtures discharge into a grease interceptor, the required vented
flow control device shall be installed between the vented fixture traps and the interceptor.

EXCEPTION: A grease interceptor with the required flow control device shall be permitted to serve as a trap
for an individual fixture if the developed length of the dram between the fixture and the interceptor does not
exceed four feet horizontally and 30 inches vertically.
See Figure 6.2, 2-A and-B

2006 National Standard Pmihitit Coa\'-l!hisnwed

153

AIR INTAKE FOR

FLOW CONTROL DEVICE

MULTIPLE SINK COMPARTMENTS
WITH ONE OR MORE VENTED TRAPS

FIXTURE TRAP -

VENT TO
ATMOSPHERE

ACCESSIBLE GREASE INTERCEPTOR
ABOVE OR BELOW FLOOR

WASTE DRAIN

NOTES:

1. Flow control devices are necessary to prevent the waste flow from exceeding the design flow rating
of the grease interceptor.

2. When the fixtures connected to the grease interceptor have traps, the air intake on the flow control
device must be connected to the fixture vent piping system.

3. Air intake through the flow control device aerates the grease-iaden waste, which is essential to the
separation process.

Figure 6.2.2 - A
A GREASE INTERCEPTOR SERVING TRAPPED AND VENTED FIXTURES

SINK OR DISHWASHER
FIXTURE OVERFLOW LEVEL

AIR INTAKE WITH
V~~ RETURN BEND

VENT TO
ATMOSPHERE

30" MAX.

FLOW
CONTROL-
DEVICE

6" MIN.

p~**:

-4'-er max.-

■ ACCESSIBLE GREASE INTERCEPTOR
ABOVE OR BELOW FLOOR

WASTE DRAIN

NOTES:

1. When a fixture that is connected to a grease interceptor is within 4 feet horizontally and 30 inches
vertically from the inlet to the interceptor, a fixture trap is not required. If the fixture is not trapped,
the air intake for the flow control device must not be connected to the vent piping system. It must
be terminated at a 1 80 degree return bend with its inlet at least 6 inches above the flood level of the
fixture.

Figure 6.2,2 - E
A GREASE INTERCEPTOR SERVING AS A FIXTURE TRAP

154

200C> National Slumlord Pumbinv Cotfe-lliiistriited

6.2.3 Food Waste Grinders

Where food waste grinders discharge through a grease interceptor, a solids interceptor shall be installed
upstream of the grease interceptor to prevent food particles from entering the grease interceptor. See
Figure 6.2.3

AIR INTAKE FOR

FLOW CONTROL DEVICE

FIXTURE TRAP
VENT

SINK

FOOD WASTE -
GRINDER

SOLIDS SEPARATOR

VENT TO
ATMOSPHERE

ACCESSIBLE GREASE INTERCEPTOR
ABOVE OR BELOW FLOOR

WASTE DRAIN

Figure 6.2.3
A FOOD WASTE GRINDER WITH SOLIDS SEPARATOR AND GREASE INTERCEPTOR

6.2.4 Commercial Dishwashers

Commercial dishwashers shall be permitted to discharge through a grease interceptor.

6.2.5 Location

Grease interceptors shall be permitted to be installed within buildings unless otherwise prohibited by the
Authority Having Jurisdiction. Where interceptors or holding tanks are remote from the fixtures served, the
drain piping between the fixtures and the interceptor or holding tank shall be as direct as possible and shall
include provisions for periodic cleaning.

6.2.6 Prohibited Interceptors

The installation of water-cooled grease interceptors shall be prohibited.

6.2.7 Chemicals Prohibited

Theuse ofenzymes, emulsifiers, or similar chemicalsin grease interceptors shall be prohibited.

6.2.8 Individual Dwelling Units

Grease interceptors shall not be required in individual dwelling units or any private living quarters.

2006 National Standard PumMns Code-flluxtrated

155

6.3 OIL/WATER SEPARATORS

6.3.1 Where Required and Approved Point of Discharge

a. Liquid waste containing grease, oil, solvents, or flammable liquids shall not be directly discharged into
any sanitary sewer, storm sewer, or other point of disposal. Such contaminants shall be removed by an
appropriate separator.

b. Sand interceptors and oil separators shall be provided wherever floors, pits or surface areas subject to
accumulation of grease or oil from service or repair operations are drained or washed into a drainage system.
Such locations include, but are not limited to, car or truck washing facilities, engine cleaning facilities, and
similar operations. The drainage or effluent from such locations shall be connected to the sanitary sewer.

c. Drains shall not be required in service or repair garages that employ dry absorbent cleaning methods;
however, if any drains are located in such areas, they shall discharge to the sanitary sewer through a sand
interceptor and oil interceptor.

d. Drains shall not be required in parking garages unless the garage, or portions thereof, has provisions for
either washing vehicles or rinsing the floor. Where such cleaning facilities are provided, the area subject to
waste drainage shall be provided with one or more floor drains, complete with sand interceptor and oil inter-
ceptor, and the effluent from the oil separator shall be connected to the sanitary sewer. Any storm water shall
be drained separately and directly to the storm sewer.

e. Where parking garages without provisions for vehicle washing or floor rinsing require storm water
drainage, drains shall be permitted to connect to the storm sewer without a sand interceptor and oil separator.
Such drainage, including melting snow, ice or rainwater runoff from vehicles, shall not be connected to the
sanitary sewer.

f. Where oil separators include a waste holding tank, it shall not be used to store or contain any other
waste oil (e.g., motor oil) or hazardous fluid.

6.3.2 Design of Oil Separators

a. Where oil separators are required in garages and service stations, they shall have a minimum volume of
six cubic feet for the first 100 square feet of area drained, plus one cubic foot for each additional 100 square
feet of area drained. Oil separators in other applications shall be sized according to the manufacturers rated
flow.

b. Field-fabricated oil separators shall have a depth of not less than two feet below the invert of the
discharge outlet. The outlet opening shall have a water seal depth of not less than 18 inches.

c. Manufactured oil separators shall be sized according to gallons per minute of rated flow. They shall
include a flow control device and adjustable oil draw-off.

d. Oil separators shall have a 3-inch minimum discharge line and a 2-inch minimum vent to atmosphere.
The discharge line shall have a full-size cleanout extended to grade or otherwise be accessible.

e. The oil draw-off or overflow piping from oil separators shall be connected to an approved waste oil tank
that is installed and permitted according to the environmental requirements of the Authority Having Jurisdic-
tion. The waste oil from the separator shall flow by gravity or may be pumped to a higher elevation by an
automatic pump. Pumps shall be adequately sized, explosion-proof, and accessible. W r aste oil tanks shall have
a 2-inch minimum pump-out connection and a 1-1/2 inch minimum vent to atmosphere.

f. Where oil separators are subject to backflow from a sewer or other point of disposal, their discharge
line shall include a backwater valve, installed in accordance with Section 5.5.

g. Where oil separators are installed in parking garages and other areas where the waste flow will include
sand, dirt or similar soilds. a sand interceptor shall be provided upstream from the oil separator. Sand intercep-
tors shall comply with Section 6.4.

h. Oil interceptors, waste oil tanks, oil pump-out connections, backwater valves and atmospheric vent
piping shall be permanently identified by suitable labels or markings.

156 2006 iWationul SuuuturJ Pumbinv Code-Illusiwiet!

6.3.3 Vapor Venting

The atmospheric vents from oil separators and their waste holding tanks shall be separate from other plumb-
ing system vents and shall be extended to an approved location at least 12 feet above grade or the surround-
ing area.

6.3.4 Combination Oil Separator and Sand Separator

A combination oil separator and sand separator meeting the functional requirements of Sections 6.3 and 6.4
shall be permitted to be installed.

6.4 SAND INTERCEPTORS

6.4.1 Where Required

a. A sand interceptor shall be installed upstream from an oil separator if required in Section 6.3.2.g.

b. A sand interceptor shall be provided downstream from any drain whose discharge may contain sand,
sediment, or similar matter on a continuing basis that would tend to settle and obstruct the piping in the
drainage system. Multiple floor drains shall be permitted to discharge through one sand interceptor.

6.4.2 Construction and Size

a. Sand interceptors shall be constructed of concrete, brick, fabricated coated steel, or other watertight
material, and shall be internally baffled to provide an inlet section for the accumulation of sediment and a
separate outlet section.

b. The outlet pipe of a sand interceptor shall be the same size as the drain served.
EXCEPTION: If serving an oil separator, the outlet from the sand interceptor shall be the same size as the
inlet to the oil separator.

c. The inlet baffle shall have two top skimming openings, each the same size as the outlet pipe and at the
same invert as the outlet opening. The openings in the baffle shall be offset to prevent straight-line flow
through the interceptor from any of its inlets to its outlet.

d. The inlet to the interceptor shall be at the same elevation as, or higher than, the outlet. The bottom of
the inlet section shall be at least 24 inches below the invert of the outlet pipe.

e. The bottom of the inlet section shall be at least two feet wide and two feet long for flow rates up to 20
gallons per minute. The bottom of the inlet section shall be increased by one square foot for each 5 gpm of
flow- or fraction thereof over 20 gpm. The bottom of the outlet section shall be not less than 50% of the area
of the bottom of the inlet section.

f. A solid removable cover shall cover the outlet section. An open grating suitable for the traffic in the
area in which it is located shall cover the inlet section. Covers shall be set flush with the finished floor.
See Figures 6.4.2-A and-B

2006 National SumJurd Pumhin" Code— Illustrated 157

GRATE

SOLID ACCESS COVER

GRADE OR
■ FLOOR LINE

nihil I n ^i'AVA^mst-j

STAGGERED FLOW_
OPENINGS

INLET SLIGHTLY
HIGHER THAN
OUTLET

24" MIN

.SEDIMENT—

3 TO OIL/WATER SEPARATOR

■WATERPROOFING

INLET SECTION-

■ OUTLET SECTION

SECTION VIEW

NOTES:

1. Where a sand interceptor is installed upstream from an oil separator, the sand interceptor does not

have to include a 6" trap seal depth. The oil separator provides the trap seal that blocks the flow of

sewer gas from the building sewer into the building.

Figure 6.4.2 - A
A SAND INTERCEPT0R SERVING AN OIL SEPARATOR

GRATE AND
ACCESS COVER
REMOVED

INLET

OUTLET

. ii 6

PLAN VIEW

SOLID REMOVABLE
COVER

GRADE OR
FLOOR LINE

INVERT OF OUTLET

INLET S~E

-Li

I I ih liyAXSSSWSS

STAGGERED TOP
SKIMMING OPENINGS

24" MINj_rz SEDIMENTrz

• 6" MINIMUM TRAP SEAL

f=P

J OUTLET

-WATERPROOFING

INLET SECTION ■

-OUTLET SECTION

SECTION VIEW

NOTES:

1. Where a stand-alone sand interceptor is installed, it must include a 6" trap seal depth to block the
flow of sewer gas from the building sewer into the building.

Figure 6.4.2 - B
A STAND-ALONE SAND INTERCEPTOR

158

200b National Standard fumbini; Code-IUusmned

6.4.3 Water Seal

When a sand interceptor is used separately without also discharging through an oil separator, its outlet pipe
shall be turned down inside the separator below the water level to provide a six-inch minimum water seal. A
cleanout shall be provided for the outlet line.

6.4.4 Alternate Design

Alternate designs for construction of, or baffling in. sand interceptors shall comply with the intent of this Code
and be submitted to the Authority Having Jurisdiction for approval.

6.5 SOLIDS INTERCEPTORS

a. Solids interceptors shall be provided where necessary to prevent harmful solid materials from entering the
drainage system on a continuing basis. Such harmful materials include, but are not limited to, aquarium gravel,
barium, ceramic chips, clay, cotton, denture grindings, dental silver, fish scales, gauze, glass particles, hair, jewels,
lint, metal grindings, plaster, plastic grindings, precious metal chips, sediment, small stones, and solid food particles.

b. Solids interceptors shall separate solids by gravity, trapping them in a removable bucket or strainer.

c. Solids interceptors shall be sized according to their drain pipe size or by the required flow rate.

6.6 NEUTRALIZING AND DILUTION TANKS

a. Neutralizing or dilution tanks shall be provided where necessary to prevent acidic or alkaline waste from
entering the building drainage system. Such waste shall be neutralized or diluted to levels that are safe for the
piping in the drainage and sewer systems.

b. Vents for neutralizing or dilution tanks shall be constructed of acid-resistant piping and shall be independent
from sanitary system vents.

6.7 SPECIAL APPLICATIONS

6.7.1 Laundries

Commercial laundries shall be equipped with one or more lint interceptors having wire baskets or similar
devices, removable for cleaning, that will prevent passage into the drainage system of solids 1/2 inch or larger
in size, strings, rags, buttons, lint, and other materials that would be detrimental to the drainage system.

6.7.2 Bottling Establishments

Bottling plants shall discharge their process wastes into a solids separator that will retain broken glass and
other solids, before discharging liquid wastes into the drainage system.

6.7.3 Slaughter Houses

Drains in slaughtering rooms and dressing rooms shall be equipped with separators or interceptors, approved
by the Authority Having Jurisdiction, that will prevent the discharge into the drainage system of feathers,
entrails, and other waste materials that are likely to clog the drainage system.

6.7.4 Barber Shops and Beauty Parlors

Shampoo sinks in barbershops, beauty parlors, and other grooming facilities shall have hair interceptors
installed in lieu of regular traps.

2006 National Standard Pumbins Code-IUustraied 159

Blank Page

160 2006 National Slumlord Pumbin.v Code-Illustrated

•

Chapter 7

Plumbing Fixtures, Fixture Fittings and
Plumbing Appliances

7.1 FIXTURE STANDARDS

Plumbing fixtures, plumbing fixture trim, and plumbing appliances shall comply with the standards listed in Table
3.1.3.

7.2 FIXTURES FOR ACCESSIBLE USE

Plumbing fixtures for accessible use and their installation shall confirm to the requirements of the Authority Having
Jurisdiction.

7.3 INSTALLATION

7.3.1 General

Plumbing fixtures, fixture trim, and plumbing appliances shall be installed in accordance with the requirements
of this Code and the manufacturer's instructions and recommendations.

7.3.2 Minimum Clearances

For other than accessible applications, minimum clearances between plumbing fixtures and from fixtures to
adjacent walls shall be in accordance with Figure 7.3.2.

7.3.3 Access for Cleaning

Plumbing fixtures shall be so installed as to provide access for cleaning the fixture and the surrounding area.

7.3.4 Securing Floor-Mounted Fixtures

Floor-mounted fixtures shall be securely supported by the floor or floor/wall structure. No strain shall be
transmitted to the connecting piping. Fastening screws or bolts shall be corrosion-resisting.

2006 National Standard Plumbing Code-Illustrated

161

30"

W//////////////////////,

60"
CLEAR

COMPART-
MENT

WATER CLOSETS
OR BIDETS

OTHER BUILDINGS
DWELLINGS

WALL

CLEARANCE

WALL

wy//mmwMW//M

— — | 15" l-

^ 3 'H

|7 L !

■mm.

— 30" -*-

W//A¥///////////^^^

WALL

21"
CLEARANCE

URINALS

-2"

yyyw/ »«»y wyy«» Y/MV/////^//// ^

H2Lu£HE3

V i ^ I v 1 <■ S— .. i <"

21"

WALL CLEARANCE L*. 30 » ^J

LAVATORIES

TUB <■

m%^g^mmm.

SHOWERS

The clear height between ceilings and

floors shall comply to the requirement of

the Building Code.

24" CLEARENCE IN FRONT OF OPENING

Figure 7.3.2
MINIMUM FIXTURE CLEARANCES

162

2006 National Standard Plumbing Code-Illustrated

7.3.5 Supporting Wall-Hung Fixtures

a. Wall-hung water closets shall be supported by concealed metal carriers that transmit the entire weight
of the fixture to the floor and place no strain on the wall or connecting piping. Supports of this design shall
comply withASMEAl 12.6.1.

b. Free-standing lavatories, wall-hung urinals, water closets with or without concealed tanks and other
wall-mounted fixtures shall be supported by a concealed or exposed finished wall hanger plate or equivalent
that transmits the weight of the fixture to the wall structure, if adequate, or to the floor without placing strain
on the piping. Such supports shall comply with ASME A 1 1 2.6.2 or ASME A 1 1 2. 1 9. 1 2. In addition to the wall
support brackets, pedestals or legs may provide additional support for pedestal lavatories.

See Figure 7.3.5

WALL

-SUPPORT IS ENTIRELY ON
CARRIER BOLTS

CARRIER BODY

LAG SCREW AND ANCHOR

•

NOTES:

1 . Wall hung water closets are designed to be supported by carriers.

2. For fixtures other than water closets, such as lavatories and urinals, the carrier may be either floor
or wall supported, depending on the strength of the wall.

Figure 7.3.5
A CARRIER FOR A WALL HUNG WATER CLOSET

7.3.6 Orientation and Operation of Faucets

Where fixtures are supplied with both hot and cold water, the faucet(s) and supply piping shall be installed so
that the hot water is controlled from the left side of the fixture or faucet when facing the controls during
fixture use.

EXCEPTION: Single handle and single control valves for showers and tub/shower combinations where the
hot and cold temperature orientation is marked on the fitting surface.

7.3.7 Access to Concealed Connections

Where fixtures have drains with concealed slip joint connections or incorporate a cleanout plug, a means of
access shall be provided for inspection and repair. Such access is not required for connections that are
soldered, threaded, solvent cemented, or equivalently secured.

Comment: Access to concealed slip joints and cleanouts can require the use of tools.

2006 National Standard Plumbing Code-Iliustrated

163

7.3.8

Joints

7.3.8

Joints with Walls and Floors

where fixtures contact walls and floors shall be caulked or otherwise made water-tight. See Figure

ESCUTCHEON

LAVATORY

■ SEAL EDGES
AND SIDES

R^^^W^^

SEAL EDGES
AROUND BASE

•

^^^S^^^

WALL HUNG WATER CLOSET

FLOOR MOUNTED WATER CLOSET

SEAL
EDGES
AND AT

^^^^^^^^^ FL00R

v. \ I

SHOWER STALL

BATHTUB

NOTES:

1 . Openings or gaps between fixtures and walls or floors can collect dirt and moisture. They are
unsanitary and can cause water damage to the building structure. These openings must be caulked
or otherwise sealed.

Figure 7.3.8
SEALING FIXTURES TO WALLS AND FLOORS

7.4 WATER CLOSETS

7.4.1 Compliance

Vitreous china water closets shall comply with ASME A 1 1 2. 1 9.2M. Plastic water closets shall comply with
ANSI Z124.4.

7.4.2 Water Conservation

Water closets, whether operated by flush tank, flushometer tank, or flushometer valve, shall comply with
ASME A 1 12.19.2M and shall be the low-consumption type having an average consumption of not more than
i.6 gallons per flush when tested in accordance with ASME Al 12.19.6.
EXCEPTION: Blow-out water closets and clinical sinks.

164

2006 National Standard Plumbing Code-Illustrated

7.43 Contour of Bowls

Water closets shall have elongated bowls with open-front seats.
EXCEPTIONS:

(1) Water closets having closed-front seats and either round or elongated bowls shall be permitted in
dwelling units.

(2) Water closets having closed-front seats that are protected by automated seat cover protection.

(3) A water closet in a private office toilet room, intended for the exclusive use of one individual.

(4) Water closets intended for use in pre-school and kindergarten facilities.
See Figure 7.4.3-A and-B

REGULAR BOWL

ELONGATED
BOWL

RIM

13 1/2" MINIMUM

{SEE EXCEPTIONS IN

FIGURES 7.4.4-A and

7.4.4-B)

•

NOTES:

1 . See Figure 7.4.4 - A for bowl heights for children's use.

2. See Figure 7.4.4 - B for bowl heights for adult accessible use.

Figure 7.4.3 - A

AN ADULT-HEIGHT ELONGATED WATER CLOSET BOWL

COMPARED TO A ROUND BOWL

NOTES:

1 . Seats for water closets must fit the water closet bowl. Section 7.4.5 requires elongated seats on
elongated bowls and round seats on round bowls.

Figure 7.4.3 - B
AN 0pEN FRONT ELONGATED WATER CLOSET SEAT (LESS LID)

2006 National Standard Plumbing Code— Illustrated

165

7.4.4 Bowl Height

The height of water closet bowls shall be a minimum of IVA inches from the floor to the top of the rim.
EXCEPTIONS:

(1) Bowls intended for children's use (5 years and younger) are permitted to be 9-1/2" to 10-1/2" high to the
rim and juvenile use (6-12 years) are permitted to be 10-1/2" to 13-1/2" high to the rim.

(2) The height of bowls intended

that the top of the seat is 1 1" to 17" above the floor and comply with Section 7.2.

(3) The height of bowls intended specifically for adult accessible use (13 years and older) shall be such that
the top of the seat is 17" to 19" above the floor and comply with Section 7.2.

See Figures 7.4.3-A, 7.4.4-A, and 7.4.4-B.

APPLICATION

AGE - YEARS

HEIGHT "H"

CHILDREN'S USE

5 & YOUNGER

9-1/2" TO 10-1/2" TO RIM

JUVENILE (CHILDREN'S) USE

6-12

10-1/2" TO 13-1/2" TO RIM

ACCESSIBLE CHILDREN'S USE

12 & YOUNGER

1 1 " TO 1 7" TO TOP OF SEAT

^^^^^^^^^^^^^^^^^^^

Figure 7.4.4 - A
PERMITTED HEIGHTS OF WATER CLOSET BOWLS FOR CHILDREN'S USE

17" -19"

TOP OF SEAT

^^^^^^^^^^^^^^^^^^^?

Figure 7.4.4 - B
PERMITTED HEIGHT OF WATER CLOSET BOWLS FOR ADULT ACCESSIBLE USE

•

166

2006 National Standard Plumbing Code-Illustrated

•

7.4.5 Water Closet Seats

Seats for water closets shall be of smooth, non-absorbent materials, be properly sized to fit the water closet

bowl, and comply with ANSI Z124.5

EXCEPTION: Water closet seats in dwelling units are not required to comply with ANSI Z124.5.

7.4.6 Hotels, Motels, Dormitories, and Boarding Houses

Water closets in hotels, motels, dormitories, boarding houses and similar occupancies shall be the elongated
type complying with ASME A 11 2. 1 9.2 or ANSI Z 1 24.4, and ASME A 1 1 2. 1 9.6 and with open-front seats
complying with ANSI Z 1 24.5
EXCEPTIONS:

(1) Closed-front seats shall be permitted in hotel and motel guest rooms.

(2) Closed-front seats that are provided with automatic seat cover protection.

7.4.7 Prohibited Water Closets

Water closets not having a visible trap seal or having either unventilated spaces or walls that are not washed
at each discharge shall be prohibited.

7.4.8 Macerating Toilet Systems

Macerating toilet systems and related components shall comply with ASME Al 12.3.4 or CSA B45.9.

7.5 URINALS

7.5.1 Compliance

a. Urinals with a non-visible water trap seal and/or strainer shall be equipped with an automatic flushing
device.

b. Vitreous china urinals shall comply with ASME A 1 12.19.2.

c. Plastic urinals, including female urinals, urinals for the physically impaired, and waterless male urinals,
shall comply with ANSI Z 124.9.

7.5.2 Water Conservation

Water-fed urinals shall be the low-consumption type having an average water consumption of not more than
1.0 gallon per flush when tested in accordance with ASME Al 12.9.6.

7.5.3 Surrounding Surfaces

Urinals shall not be installed where wall and floor surfaces are not waterproof and do not have a smooth,
readily cleanable, non-absorbent surface extending not less than four feet above the floor and one foot to
each side of the urinal, and one foot in front of the lip of the urinal. See Figure 7.5.3.

7.5.4 Prohibited Urinals

Trough urinals and urinals having walls that are not washed at each discharge shall be prohibited.
EXCEPTION: Waterless urinals complying with ANSI Z124.9.

2006 National Standard Plumbing Code-Illustrated 167

r-o"

AREA THAT
MUST BE
COVERED WITH
A WATERPROOF
MATERIAL

X EQUALS THE DEPTH OF THE URINAL

Figure 7.5,3
PROTECTING SURROUNDING SURFACES AT URINALS

7.6 LAVATORIES

7.6.1 Compliance

a. Lavatories shall comply with the following standards:

1 . Ceramic, non-vitreous; ASME A 11 2. 1 9.9M

2. Enameled cast-iron; ASME A 1 12.19.1M

3. Enameled steel; ASME A 112. I9.4M

4. Plastic; ANSI Z 124.3

5. Stainless steel; ASME A 112.1 9.3M

6. Vitreous china; ASME Al 12. 1 9.2M

7.6.2 Water Conservation

a. Except as required under Section 7.6.2. c, lavatory faucets shall be designed and manufactured so that
they will not exceed a water flow rate of 2.2 gallons per minute when tested in accordance with ASME
Al 12.18.1.

b. Public lavatory faucets, other than the metering type, shall be designed and manufactured according to
ASMEA112.18.1.

c. Self-closing or self-closing/metering faucets shall be installed on lavatories intended to serve the
transient public, such as those in, but not limited to, service stations, train stations, airport terminals, restau-
rants, and convention halls. Metering faucets shall deliver not more than 0.25 gallon of water per use when
tested in accordance with ASME Al 12.18.1. Self-closing faucets shall be designed and manufactured so
that they will not exceed a water flow rate of 0.5 gallon per minute when tested in accordance with ASME
A112.18.1.

168

2006 National Standard Plumbing Cude-llhistraied

7.6.3 Waste Outlet

The waste outlet pipe on individual lavatories shall be not less than 1-1/4" nominal size. A strainer, pop-up
stopper, crossbar grid, or other device shall be provided to protect the waste outlet.

7.6.4 Integral Overflow

Where lavatories include an integral overflow drain, the waste fitting shall be designed and installed so that
standing water in the bowl of the fixture cannot rise in the overflow channel when the drain is closed, nor
shall any water remain in the overflow channel when the bowl is empty. The overflow shall drain to the inlet
side of the fixture trap. See Figure 7.6.4

Comment: Overflows are not provided in all lavatories. Lavatories with overflows are not used in
hospitals because of the potentially unsanitary condition caused by inaccessible surfaces exposed to
waste.

OVERFLOW OPENING
(WHERE PROVIDED)

POP-UP WASTE —i

1 j j- j -r-r-r-.

^zzzpza

OVERFLOW TO DISCHARGE INTO
FIXTURE SIDE OF TRAP

POP-UP LEVER

Figure 7.6.4
A LAVATORY OVERFLOW

7.6.5 LavatoryEquivalent

Where group-type wash fountains or wash sinks are used to satisfy the number of lavatories required by
7.21.1, each 18-inch usable length of rim having an available water spray shall be considered as one lavatory.
See Figure 7.6.5

2006 National Standard Plumbing Code-Illustrated

169

EACH 18" IS EQUIVALENT
TO 1 LAVATORY

SPRAY
HEAD

PLAN ELEVATION

Figure 7.6.5
A CIRCULAR WASH FOUNTAIN

7 1 umrTC

7.7.1 Compliance

Vitreous china bidets shall comply with ASME Al 12.19.2M. Bidet faucets shall comply to ASME
A112.18.1.

7.7.2 Backflow Prevention

Bidets having integral flushing rims shall have a vacuum breaker assembly on the mixed water supply to the
fixture. Bidets without flushing rims shall have an over-the-rim supply fitting providing the air gap required by
Chapter 10.

7.7.3 Integral Overflow

Where bidets include an integral overflow drain, the waste fitting shall be designed and installed so that
standing water in the bowl of the fixture cannot rise in the overflow channel when the drain is closed, nor
shall any water remain in the overflow channel when the bowl is empty. The overflow shall drain to the inlet
side of the fixture trap.

/.o DAlnl Udo

7.8.1 Compliance

a. Bathtubs shall comply with the following standards:

1 . Plastic, cultured marble and other synthetic products or finishes; ANSI Zl 24. 1

2. Enameled cast-iron; ASME A 11 2. 19.1

3. Enameled steel; ASME A 11 2. 1 9.4

4. Bathtubs with pressure sealed doors; ASME A 1 12.19.15

7.8.2 Waste and Overflow

Bathtubs shall have waste outlet and overflow pipes not less than 1-1/2" nominal size. Waste outlets shall be
equipped with a pop-up waste, chain and stopper, or other type of drain plug. See Figure 7.8.2

170 2006 National Standard Plumbing Code-Illustrated

•

TRIP LEVER

OVERFLOW TO DISCHARGE INTO
FIXTURE SIDE OF TRAP

POP-UP WASTE SHOWN

flow r

Figure 7.8.2
A BATHTUB WASTE AND OVERFLOW

7.8.3 Combination Bath/Showers

Shower heads, including the hand-held type, shall be designed and manufactured so that they will not exceed
a water supply flow rate of 2.5 gallons per minute when tested in accordance with ASME Al 12.18.1 , The
control of mixed water temperatures to bath/shower combinations shall comply with Section 1 0. 1 5.6. Sur-
rounding wall construction shall be in accordance with Section 7.10.5.e. Riser pipes to shower heads shall be
secured in accordance with Section 7.10.7.

7.8.4 Backflow Prevention

Unless equipped with an atmospheric backflow preventer in accordance with ASSE 1001 or ASME

Al 12.18.7, the bathtub filler shall be equipped with an air gap between the end of the over-rim tub filler spout

and the overflow rim of the tub that complies with Section 10.5.

7.9 WHIRLPOOL BATHS

7.9.1 General

The requirements of Section 7.8 for bathtubs shall also apply to whirlpool baths. The provisions for wet
venting in Section 1 2. 1 shall also apply to whirlpool baths.

7.9.2 Compliance

Whirlpool bathtubs shall comply with ASME A J 1 2. 1 9.7M.

7.9.3 Drainage

The arrangements of circulating piping and pumps shall not be altered in any way that would prevent the
pump and associated piping from draining after each use of the fixture.

7.9.4 Access

One or more removable panels shall be provided where required for access to pumps, heaters, and controls,
as recommended by the fixture manufacturer. See Figure 7.9.4

2006 National Standard Plumbing Cade-Illustrated

171

ACCESS REQUIRED
AS RECOMMENDED
BY THE MANUFACTURER

■///////////

1 , Access must be provided to electrical and plumbing components of whirlpool baths as recom-
mended by the manufacturer. Refer to manufacturer's installation instructions.

Figure 7.9.4
ACCESS REQUIREMENTS FOR A WHIRLPOOL BATH

7.10 SHOWERS

7.10.1 Compliance

Plastic shower receptors and stalls shall comply with ANSI Z 124.2.

7.10.2 Water Conservation

Shower heads shall be designed and manufactured so that they wilt not exceed the flow rate for shower head
specified inASME All 2.1 8. 1M.
EXCEPTION: Emergency safety showers.

7.10.3 Control of Mixed Water Temperature

The control of mixed water temperatures shall comply with Section 10.15.6.

7.10.4 Shower Waste Outlet

a. For a shower with a single shower head, the waste outlet connection shall be not less than 1-1/2" inches
nominal size and for a shower with multiple shower heads shall be not less than 2 inches nominal size and
have a removable strainer not less than 3 inches in diameter with %" minimum openings.
EXCEPTIONS:

(1) Bathubs with overhead showers.

(2) Waste outlets shall be securely connected to the drainage system.

(3) In group showers where each shower space is not provided with an individual waste outlet, the waste
outlet(s) shall be so located and the floor so pitched that waste water from one outlet does not flow over the
floor area serving another outlet.

7.10.5 Shower Compartments

a. The minimum outside rough-in dimension for shower bases and prefabricated shower compartments
shall be 32 inches,

b. The minimum rough-in depth for prefabricated tub/shower combinations shall be 30 inches.

c. Where shower compartments have glass enclosures or field-constructed tile walls, the compartment
shall provide clearance for a 30 inch diameter circle with the door closed.

d. The minimum rough-in depth for shower compartments that replace existing bathtubs shall be no less
than the rough-in depth of the bathtub that they replace. Such enclosures shall provide not less than 900
square inches of inside clear floor area,

e. The walls in shower compartments and above built-in bathtubs having installed shower heads shall be
constructed of smooth, non-corrosive, non-absorbent waterproof materials that extend to a height of not less

172 2006 National Standard Plumbing Code-Illustrated

than 68 inches above the fixture drain,
f. The joints between walls and with bathtubs and shower compartment floors shall be water-tight.

7.10.6 Shower Floors or Receptors

a. Floors or receptors for shower compartments shall be laid on or be supported by a smooth and structur-
ally sound base.

b. Shower pans shall be provided under the floors of shower compartments.
EXCEPTION: Shower pans shall not be required when prefabricated shower receptors are used.

c. Shower pans shall form a watertight lining beneath the shower floor.

d. Shower pans shall turn up at least 2 inches above the finished threshold level on all sides.

e. Shower pans shall be securely fastened to the shower waste outlet at the seepage entrance, making a
watertight joint between the pan and the waste outlet.

f. Finlhed shower floor surfaces shall be smooth, non-corrosive, non-absorbent, and waterproof.
See Figure 7.10.6

WATERPROOF MEMBRANE AT LEAST 2"
MINIMUM ABOVE THRESHOLD HEIGHT

WEEP HOLES FOR
SECONDARY DRAINAGE

-FLUSH WITH FINISHED SURFACE

. FINISHED SURFACE
GRADED TO DRAIN

CLAMPING RING

WATERPROOF PAN OR LINER
UNDER CLAMPING RING

Figure 7.10.6

A SHOWER PAN AND DRAIN

•

7.10.7 Water Supply Riser

Whether exposed or concealed, the water supply riser pipe from the shower control valve(s) to the shower
head outlet shall be secured to the wall structure. See Figure 7.10.7

2006 National Standard Plumbing Code-Illustrated

173

SECURELY SUPPORTED
WITH DROP EAR ELL

ALTERNATE
ARRANGEMENT

TO SHOWER VALVE

WATERPROOF
WALL {Section 7.10.5)

SHOWER CONTROL VALVE

^>- SEALED (Section 7.3.8)
i— AIR GAP

TOP OF BATHTUB

SEALED
(Section 7.3-8)

Figure 7.10.7
A SHOWER HEAD SUPPLY RISER PIPE

7.11 SINKS

7.11.1 Compliance

a. Sinks shall comply with the following standards:

1 . Enameled cast-iron; ASME A 1 1 2. 1 9. 1 M

2. Enameled steel; ASME A112.19.4M

3. Stainless steel; ASME A112.19.3M

4. Plastic; ANSI Z124.6.

7.11.2 Kitchen Sinks and Bar Sinks

a. Each compartment in a kitchen sink or bar sink shall have an outlet suitable for either a domestic food
waste grinder or a basket strainer. The waste outlet pipe for each compartment shall be 1-1/2" nominal size.
Outlet fittings shall have crossbars or other provisions for protecting the drain outlet and shall include a means
of closing the drain outlet.

b. Faucets for kitchen sinks and bar sinks shall be designed and manufactured so that they will not exceed
a water flow rate of 2.2 gallons per minute when tested in accordance with ASME Al 12.1 8.1 M.

See Figure 7.11.2

174

2006 National Standard Plumbing Code-Illustrated

•

30" MAXIMUM
FOR ONE TRAP

BASKET STRAINER
1V 2 "

CONTINUOUS

WASTE

ASSEMBLY

DOMESTIC FOOD
WASTE GRINDER

TRAP

Figure 7.11.2
KITCHEN SINK DRAIN OUTLETS

7.11.3 Laundry Sinks

a. Sinks for laundry use shall be not less than 12 inches deep with a strainer and waste outlet connection not
less than 1 - 1 /2" nominal size.

b. Utility faucets for laundry sinks shall comply with ASME A 11 2. 1 8.1 .

7.11.4 Service Sinks and Mop Receptors

a. Service sinks and mop receptors shall have removable strainers and waste outlet connections not less
than 2 " nom inal size.

b. Service sinks and mop receptors shall not be installed where walls and floors are not waterproof and do
not have a smooth, readily cleanable surface at least one foot in front of the sink or receptor, at least one foot
on each side, and up to a point one foot above the faucet height.

7.11.5 Sink Faucets

a. Sink faucets having a hose thread or other means of attaching a hose to the outlet shall be protected
from back-siphonage by either an integral vacuum breaker, an atmospheric vacuum breaker attached to the
outlet, or pressure-type vacuum breakers on the fixture supply lines.

b. Faucets for kitchen sinks shall be designed and manufactured so that they will not exceed the flow rate
for kitchen faucet specified in ASME A 1 12.1 8. 1M.

7.12 DRINKING FOUNTAINS AND WATER COOLERS

7.12.1 Compliance

Refrigerated drinking fountains and water coolers shall comply with ARJ 1010 and UL 399.

7.12.2 Prohibited Locations

Drinking fountains or water coolers shall not be located in public toilet rooms.

EXCEPTION: Convertible lavatory faucets and fixture fittings that provide a discharge stream similar to a

drinking fountain shall be permitted in bathrooms in dwelling units.

2006 National Standard Plumbing Code— Illustrated

175

7.13 AUTOMATIC CLOTHES WASHERS

7.13.1 Compliance

Automatic clothes washers shall comply with ARAM HLW-2PR or ASSE 1007, and shall have an air gap
incorporated in the internal tub fill line.

Comment: Automatic clothes washers that comply with the referenced appliance standards include an
internal air gap in the water fill line and do not require the installation of an external backflow preven-
tion device.

7.14 FOOD-WASTE-GRINDER UNITS

7.14.1 Compliance

Domestic food-waste-grinder units shall comply with UL 430 and either AHAM FWD-1 or ASSE 1008.

7.14.2 Domestic Units

Domestic food-waste-grinder units shall have not less than a 1-1/2" nominal waste connection to the drainage
system. Such units may connect to a kitchen sink drain outlet, as permitted under Section 7.1 1 .2. a.

7.14.3 Commercial Units

Commercial food- waste-grinder units shall be connected to the drainage system and be separately trapped
from any sink compartment or other fixture. The waste pipe size for such fixtures shall be of sufficient size to
serve the fixture but shall be not less than 2-inch nominal size. See Figure 7.14.3

•

176 2006 National Standard Plumbing Code-Illustrated

•

VACUUM BREAKER

r — n

Vj__J— N 1

6" MINIMUM

WATER
SUPPLY

SINK OR INLET CONE

J~| — SOLENOID 2 - DISCHARGE

I LJ VALVE

2" MINIMUM

iM WASTE £d

COMMERCIAL FOOD
WASTE GRINDER

2" MINIMUM TRAP

•

NOTES:

1 . The water supply to a commercial food waste grinder must be protected against back-siphonage by
a vacuum breaker.

Figure 7.14.3
A COMMERCIAL FOOD WASTE GRINDER INSTALLATION

7.14.4 Water Supply

An adequate supply of water shall be provided for proper operation of food-waste-grinders.

7.15 DISHWASHING MACHINES

7.15.1 Compliance

Domestic dishwashing machines shall comply with UL 749 and either AHAM DW-2PR or ASSE 1006.
Commercial dishwashing machines shall comply with UL 92 1 and ASSE 1 004. The water supply to
dishwashing machines shall be protected from back-siphonage by an integral air gap or other internal means.

7.15.2 Residential Sink and Dishwasher •

The discharge from a residential kitchen sink and dishwasher may discharge through a single 1-1/2" trap. The
discharge line from the dishwasher shall be not less than the size recommended by the dishwasher manufac-
turer. It shall either be looped up and securely fastened to the underside of the counter or be connected to a
deck-mounted dishwasher air gap fitting. The discharge shall then be connected to a branch inlet wye fitting
between the sink waste outlet and the trap inlet.
See Figure 7.15.2

•

2006 National Standard Plumbing Code- 1 (lust rated

/ . r— ALTERNATE DECK-MOUNTED

/ \ DISHWASHER AIR GAP FITTING

TO SINK TRAP

COUNTER TOP-

FROM DISHWASHER

Ifc"

^ffl

TRAP
TAIL PIECE WIT
DISHWASHER CONNECTION

TUBING LOOPED UP HiGH AND FASTENED
TO UNDERSIDE OF COUNTER

DOMESTIC
DISHWASHER

\ / \ \

Figure 7.15.2
A RESIDENTIAL KITCHEN SINK AND DISHWASHER

7.15.3 Residential Sink, Dishwasher, and Food-Waste-Grinder

The discharge from a residential kitchen sink, dishwasher, and food-waste-grinder may discharge through a
single 1-1/2" trap. The discharge line from the dishwasher shall be not less than the size recommended by the
dishwasher manufacturer. It shall either be looped up and securely fastened to the underside of the counter
or be connected to a deck-mounted dishwasher air gap fitting. The discharge shall then be connected either
to the chamber of the food- waste-grinder or to a branch inlet wye fitting between the food-waste-grinder
outlet and the trap inlet. See Figure 7.15.3

ALTERNATE DECK-MOUNTED
DISHWASHER AIR GAP FITTING

TO SINK TRAP

COUNTER TOP

FROM DISHWASHER

=^\

DOMESTIC ^

FOOD WASTE W(t
GRINDER

i 1 /-" i ~rr,

TRAP -

HOSE LOOPED UP HIGH AND FASTENED
TO UNDERSIDE OF COUNTER

1 ALTERNATE
CONNECTION
TO TAILPIECE

DOMESTIC
DISHWASHER

L^ _V

Figure 7.15.3
A RESIDENTIAL KITCHEN SINK, DISHWASHER, AND FOOD WASTE DISPOSAL

•

178

2006 National Standard Plumbing Code-tlhtstmied

7.15.4 Commercial Dishwashing Machine

a. Commercial dishwashing machines shall be indirectly connected to the drainage system through either
an air gap or an air break. When the machine is within 5 feet developed length of a trapped and vented floor
drain, an indirect waste pipe from the dishwasher may be connected to the inlet side of the floor drain trap.

b. Commercial dishwashers shall be permitted to discharge through a grease interceptor in accordance
with Section 6.4.2. See Figure 7.15.4

iT\/~

PRE-RINSE SPRAY
- — VACUUM BREAKER NOT REQUIRED IF AIR GAP IS MAINTAINED

*A>?

COMMERCIAL
DISHWASHER

ALTERNATE ARRANGEMENT

AIR GAP OR AIR BREAK

VENTED RECEPTOR - ™

w "

__ w ^*--^_ VENTED RECEPTOR

5 FEET MAX.

DEVELOPED

LENGTH

•

Figure 7.15.4
A COMMERCIAL D1SHWASHING MAC HINE

7.16 FLOOR AND TRENCH DRAINS

7.16.1 Compliance

Floor and trench drains shall comply with ASME Al 12.6.3 or ASME Al 12.3.1,

7.16.2 Trap Seal and Strainer

a. Floor drains shall have a water seal of not less than 2 inches and shall be fitted with a removable
strainer. The free open area of strainers shall be at least 2/3 of the cross-sectional area of the nominal drain
outlet size.

b. Where infrequently used floor drains are subject to evaporation of their trap seals, they shall either 3 ) be
provided with a 4-inch trap seal, 2) be fed from an automatic trap priming device, or 3) be arranged as
otherwise approved by the Authority Having Jurisdiction.

See Figures 7.16.2-A through-C

2006 National Standard Plumbing Code-Illustrated

179

GRATE MINIMUM AREA
MUST COMPLY WITH
A112.21.2M BASED ON
THE DRAIN OUTLET SIZE

V;*&'$

2"-4" TRAP SEAL

Figure 7.16.2 - A
A FLOOR DRAIN TRAP AND STRAINER

FLOOR DRAIN

- r~ — - 4"

DEEP SEAL

Figure 7.16.2 - B
A DEEP SEAL TRAP

WATER SUPPLY -
TO FIXTURE

' I I

- TRAP PRIMING DEVICE WITH
f BACKFLOW PROTECTION
■ (fixture branch type shown)

FLOOR DRAIN EQUIPPED
WITH PRIMER TRAPPING

■2"- 4" TRAP SEAL

NOTES:

1 . A fixture branch type trap primer can prime more than one trap if it is fitted with a multi-outlet
manifold.

Figure 7.16.2 - C
A FLOOR DRAIN WITH TRAP PRIMER

180

2006 National Standard Plumbing Code-Hi ust rated

7.163 Size of Floor Drains

a. Floor drains and their branch piping shall be sized on the basis of their normal, expected flow rate. Floor drains
shall be not less than 2" nominal size.

b. If provided for emergency showers and eyewash stations, floor drains and their fixture drain branches shall
be sized for the GPM discharge capacity of the shower or eyewash, but the drainage fixture unit (DFU) loading
on the sanitary drainage system shall be zero (0.0 DFU).

7.16.4 Required Locations for Floor Drains

a. Floor drains shall be installed in the following areas:

1 . Toilet rooms containing either two or more water closets or wall hung urinals or a combination of one or
more water closets and wall hung urinals, except in a dwelling unit.

2. Commercial kitchens.

3. Common laundry rooms in commercial buildings and buildings having more than two dwel ting units.

7.16.5 Walk-in Coolers and Freezers

Floor drains located in walk-in coolers and walk-in freezers where food or other products for human con-
sumption are stored shall be indirectly connected to the drainage system in accordance with Section 9.1.6.

7.16.6 Floor Slope

Floors shall be sloped to floor drains where drainage occurs on a regular or frequent basis, or as otherwise
required by the Authority Having Jurisdiction.

7.17 GARBAGE CAN WASHERS

Garbage can washers shall include a removable basket or strainer to prevent large particles of garbage from
entering the drainage system. The water supply connection shall be protected from back-si phonage in accordance
with Chapter 10. Garbage can washers shall be trapped and vented as required for floor drains. See Figure 7.17

BRONZE ADJUSTABLE
SPRAY N0Z2LE

SEEPAGE OPENINGS

COLLAR CAN BE USED AS
FLASHING CLAMP
(when required)

STRAINER BUCKET

mmTTn — — — supply piping

•

Figure 7:17
A GARBAGE CAN WASHER

2006 National Standard Plumbing Code-Illustrated

181

7.18 SPECIAL INSTALLATIONS

7.18.1 Protection of Water Supply

The water supply to special installations shall be protected from backflow in accordance with Chapter 10.
Examples of such special installations include decorative fountains, ornamental pools, waterfalls, swimming
and wading pools, baptisteries, and similar custom-built equipment.

7.18.2 Approval

Special installations requiring water supply and/or drainage shall be submitted to the Authority Having Juris-
diction for approval.

7.19 FLUSHING DEVICES FOR WATER CLOSETS AND URINALS

7.19.1 General

Appropriate flushing devices shall be provided for water closets, urinals, clinical sinks, and other fixtures that
depend on trap siphonage to discharge the contents of the fixture.

7.19.2 Separate Devices

A separate flushing device shall be provided for each fixture.

EXCEPTION: A single device may be used to automatically flush two or more urinals.

7.19.3 Flush Tanks: Gravity, Pump Assisted, Vacuum Assisted.

a. Flush tanks shall have ballcocks or other means to refill the tank after each discharge and to shutoff the
water supply when the tank reaches the proper operating level. Ballcocks shall be the anti-siphon type and
comply with ASSE 1002.

b. Except in approved water closet and flush tank designs, the seat of the tank flush valve shall be at least
1 inch above the flood level rim of the fixture bowl.

c. The flush valve shall be designed so that it will close tightly if the tank is flushed when the fixture drain
is clogged or partly restricted, so that water will not spill continuously over the rim of the bowl or backflow
from the bowl to the flush tank.

d. Flush tanks shall include a means of overflow into the fixture served having sufficient capacity to
prevent the tanks from overflowing with normal flow through the fill valve.

See Figure 7.19.3

182 2006 National Standard Plumbing Code-Illustrated

VACUUM BREAKER
NTERNALLY LOCATED)

VACUUM BREAKER
(EXTERNALLY LOCATED)

REFILL TUBE
TO OVERFLOW

FLOAT MECHANISM FILL TUBE

FILL TUBE

FLUSH VALVE
ASSEMBLY

REFILL TUBE
TO OVERFLOW

FLOAT MECHANISM

WATER SUPPLY WATER SUPPLY

Figure 7.19.3
FLUSH VALVES FOR WATER CLOSET FLUSH TANKS

7.19.4 Ffushometer Tanks (Pressure Assisted)

Flushometer tanks (pressure assisted) shall comply with ASSE 1 037 and shall include built-in pressure regula-
tion and backflow prevention devices.

7.19.5 Flushometer Valves

Flushometer valves shall comply with ASSE 1037 and include a vacuum breaker assembly and means of flow
adjustment. Flushometer valves shall be accessible for maintenance and repair.
See Figure 7.19.5

FLUSHOMETER
VALVE

VACUUM BREAKER

■m\

PUSH BUTTON OPERATED
FLUSHOMETER WJTH
VACUUM BREAKER

HIGH SECURITY
WATER CLOSET

TYPICAL INSTALLATION

HIGH SECURITY INSTALLATION

NOTES:

1 . Flushometer valves are permitted to be installed in an accessible plumbing chase where security is
required in detention and correctional institutions.

Figure 7.19.5
FLUSHOMETER VALVE INSTALLATIONS

2006 National Standard Plumbing Code-Illustrated

183

7.19.6 Required Water Pressure

The available water supply pressure shall be adequate for proper operation of the particular flushing devices

used, as recommended by the manufacturer.

NOTE: Some one-piece tank-type water closets require 30 psig flowing pressure and 1/2" supplies for proper

operation.

7.20 FIXTURES FOR DETENTION AND CORRECTIONAL INSTITUTIONS

Special design fixtures for use in detention and correctional institutions shall comply with the requirements of this
Code except that fixtures may be fabricated from welded seamless stainless steel and be equipped with necessary
security devices. Water closets shall be the elongated type with integral or separate seats. Urinals shall have a
continuous flushing rim that washes all four walls of the fixture.

7.21 MINIMUM NUMBER OF REQUIRED FIXTURES

7.21.1 Number of Fixtures

Plumbing fixtures shall be provided for the type of building occupancy and in the numbers not less than those
shown in Tables 7.2 1.1.

7.21.2 OccupantLoad

a. The minimum number of plumbing fixtures shall be based on the number of persons to be served by the
fixtures, as determined by the person responsible for the design of the plumbing system.

b. Where the occupant load is not established and is based on the egress requirements of a building code,
the number of occupants for plumbing purposes shall be permitted to be reduced to two-thirds of that for fire
or life safety purposes.

c. Wherever both sexes are present in approximately equal numbers, the total occupant load shall be
multiplied by 50 percent to determine the number of persons of each sex to be provided for, unless specific
information concerning the percentage of male and female occupants is available.

d. Plans for plumbing systems, where required, shall indicate the maximum number of persons to be served
by the facilities.

e. In occupancies having established seating, such as auditoriums and restaurants, the number of occupants
for plumbing purposes shall not be less than the number of seats.

7.21.3 Access to Fixtures

a. In multi-story buildings, accessibility to the required fixtures shall not exceed one vertical story.

b. Fixtures accessible only to private offices shall not be counted to determine compliance with this
section.

c. The lavatories required by Tables 7.21 . 1 for employee and public toilet facilities shall be located
within the same toilet facility as their associated water closets and urinals.

184 2006 National Standard Plumbing Code-Illustrated

7.21.4 Separate Facilities

a. Separate toilet facilities shall be provided for each sex.
EXCEPTIONS:

(1). Residential installations.

(2). In occupancies serving 15 or fewer people, one toilet facility, designed for use by no more than one
person at a time, shall be permitted for use by both sexes.

(3). In business occupancies with a total floor area of 1500 square feet or less, one toilet facility, de-
signed for use by no more than one person at a time, shal 1 satisfy the requirements for serving customers
and employees of both sexes.

(4). In mercantile occupancies with a net occupiable floor area of 1500 square feet or less that is acces-
sible to customers, one toilet facility designed for use by no more than one person at a time, shall satisfy the
requirements for serving customers and employees of both sexes.

7.21.5 Substitution and Omission ofFixtures

a. Urinals: Not more than 50% of the required number of water closets may be substituted with urinals.

b. Drinking Water Facilities: A kitchen or bar sink shall be considered as meeting the requirements for
drinking water facilities for employees.

c. Laundry Trays: Multiple dwelling units or boarding houses without public laundry rooms shall not require
laundry trays.

d. Service Sinks: Service sinks may be omitted when the Authority Having Jurisdiction determines that they
are not necessary for proper cleaning of the facility.

7.21.6 Fixture Requirements for Special Occupancies

a. Additional fixtures may be required when unusual environmental conditions or special activities are
encountered.

b. In food preparation areas of commercial food establishments, fixture requirements may be dictated by
the health and/or sanitary codes. Fixtures, fixture compartments and appliances used for rinsing or sanitizing
equipment or utensils, processing or preparing food for sale or serving, shall be installed in accordance with
Section 9.1 .1 to ensure the required protection from backflow and flooding.

c. Types of occupancy not shown in Tables 7.21.1 shall be considered individually by the Authority
Having Jurisdiction.

d. Where swimming pools operated by an apartment building, condominium, or similar multi-family dwelling
unit are restricted to the use of residents and guests of residents of dwelling units in the immediate vicinity of the
pool, the minim urn required toilet facilities for bathers within the pool compound shall be one ( 1 ) male toilet room
and one (1) female toilet room, each consisting of a water closet and lavatory as a minimum.

e. Hand washing facilities shall be provided in each examination room in a doctor's office or medical office.

7.21.7 Facilities in Mercantile and Business Occupancies Serving Customers

a. Requirements for customers and employees shall be permitted to be met with a single set of restrooms
accessible to both groups. The required number of fixtures shall be the greater of the required number for
employees or the required number for customers.

b. Fixtures for customer use shall be permitted to be met by providing a centrally located facility acces-
sible to several stores. The maximum distance of entry from any store to this facility shall not exceed 500
feet.

c. In stores with a floor area of 1 50 square feet or less, the requirement to provide facilities for employees
shall be permitted to be met by providing a centrally located facility accessible to several stores. The maxi-
mum distance of entry from any store to this facility shall not exceed 300 feet.

d. Drinking water facilities are not required for customers where normal occupancy is short term.

2006 National Standard Plumbing Code-Illustrated

185

e. For establishments less than 1 500 square feet in total floor area, one water closet and one lavatory in a
restroom with a lockable door shall be permitted to provide the requirements for serving the customers and
employees.

7.21.8 Food Service Establishments

a. Food service establishments with an occupant load of 101 or more customers shall be provided with
separate toilet facilities for employees and customers. Customer and employee toilet facilities may be
combined for customer loads of 100 or less. For employees of 1 5 or less, one toilet facility, designed for use
by no more than one person at a time, shall be permitted for use by both sexes.

b. Drinking water facilities are not required in restaurants or other food service establishments if drinking
water service is provided.

7.22 WATER TREATMENT SYSTEMS

Water softeners, reverse osmosis water treatment units, and other drinking water treatment systems shall
meet the requirements of the appropriate standards listed in Table 3.1 .3. Waste discharge from such equip-
ment shall enter the drainage system through an air gap.

7.23 SAFETY FEATURES FOR SPAS AND HOT TUBS

7.23.1 Spas and Hot Tubs

. Spas and hot tubs shall comply with the requirements of subsections 7.23.2, 7.23.3, and 7.23.4.

7.23.2 Entrapment Avoidance

There shall be nothing in the spa or hot tub that can cause the user to become entrapped underwater. Types
of entrapment can include, but not be limited to, rigid, non-giving protrusions, wedge-shaped openings, and any
arrangement of components that could pinch and entrap the user.

7.23.3 Outlets Per Pump

There shall be a minimum of two (2) suction outlets for each pump in the suction outlet system, separated by
at least 3 feet or located on two (2) different planes, such as one on the bottom and one on a vertical wall, or
one on each of two vertical walls. The suction outlets shall be piped so that water is drawn through the
outlets simultaneously by a common suction line to the pump. Blocking one suction outlet shall not create
excessive suction at other suction outlets.

7.23.4 Obstructions and Entrapment Avoidance

Where vacuum cleaning fittings are provided, they shall be located outside of the spa or hot tub and shall not
be accessible to the spa or hot tub user.

7.24 EMERGENCY EQUIPMENT

Emergency showers and eyewash stations shall comply with ANSI Z358.1

186 2006 National Standard Plumbing Code-Illustrated

•

Table 7.21.1
MINIMUM NUMBER OF REQUIRED PLUMBING FIXTURES - Page 1

No.

Classification

Use
Group

Description

No. Of Persons
of Each Sex

Water Closets
(Urinals)

Lavatories

Drinking

Water

Facilities

Bath or
Shower

Other

Male

Female

Male

Female

Assembly

A-l

Theatres and other buildings for the performing arts and
motion pictures usually with fixed seats

See Notes: 4, 6, 9, 12, 16

1 -50

1 per
1000
people

1 service sink
per floor

51 - 100

add 1

addO

add 1

101 -200

add 1

add 2

add 1

add I

201 - 300

add 1

addl

addO

addl

ea. add'l. 300
over 300

add 1

add 2

add 1

add 2

A-2

Dance halls, nightclubs and for similar purposes.
See Notes: 2,3,4,6,9, 12, 13, 16

1 -25

1 per

200

people

1 service sink
per floor

26-50

add 1

addl

add 1

51 - 100

add 1

add 2

add 1

addO

ea. add'l. 200
over 100

add 1

add 2

add 1

add 2

A-3

a) Auditoriums without permanent seating, art galleries,
exhibition halls, museums, lecture halls, libraries,
restaurants other than nightclubs, food courts.

b) Places of worship and other religious services.
Churches without assembly halls

See Notes: 4,6,9,12, 16

1 -50

1 per
1000
people

1 service sink
per floor

51 - 100

add 1

addO

addl

101 -200

add 1

add 2

add 1

201 -300

add 1

addO

add 1

ea. add'l. 300
over 300

addl

add 2

add 1

add 2

A-4
and
A-5

a) Arenas, convention halls, outdoor assembly
including grandstands, bleachers, coliseums,
stadiums, amusement park structures, fair and
carnival structures, passenger terminals.

See Notes: 2,3,4,6,9, 12, 13, 16

1 - 100

1 per
1000
people

1 service sink
per floor

101-200

add 2

add 3

add 1

add 2

201 -400

add 2

add 5

addO

add 1

ea. add'l. 200
up to 2,600

add 1

add 2

ea. add'l. 300
over 2,600

add 1

add 2

b) Recreational facilities: includes health spas, golf
courses, public swimming pools and similar uses.

See Notes: 2,3,4,6,9, 12, 16

1 -40

1 per

people

1 shower per
15 people
over 150 add
1 per 30
people

1 service sink
per floor

ea. add'l. 40
over 40

add 1

add 2

add 1

add 2

00
00

Table 7.21.1
MINIMUM NUMBER OF REQUIRED PLUMBING FIXTURES - Page 2

No.

Classification

Use
Group

Description

No. Of Persons of
Each Sex

Water Closet
(Urinals)

Lavatories

Drinki

Water

Faciliti

Bath or
Shower

Other

Male

Female

Male

Female

Business

Buildings for the transaction of business, professional
services, other services involving merchandise, office
buildings, banks, light industrial and similar uses.

See Notes: 2,4,6,7, 12, 15, 16

1 - 15

1 per

100

people

1 service
sink per
floor

16-40

add 1

addl

addO

add 1

41 -75

add 1

addl

add 1

addl

ea. add'l. 60 over

add 1

add 2

add 1

add 2

Education

a) Educational facilities: Preschool, Day Care, Kindergarten
See Notes: 4, 6, 9, 16

1 - 15

1 per

100

people

1 service
sink per
floor

16-30

add 1

31 -45

addl

add 1

46-60

add 1

61-75

add 1

76-90

addl

add 1

addl

ea. add'l. 30
over 90

add 1

addl

add 2

b) Elementary Grades 1 - 5
See Notes: 4,6,9, 16

1 -25

1 per

100

people

1 service
sink per
floor

26-50

add 1

addl

51 -75

add 1

addl

76- 100

addl

add 1

ea. add'l. 50
over 100

add 1

add 2

c) Secondary Grades 6-12 and higher education facilities
See Notes: 4, 6, 9, 16, 17

1 -30

1 per

100

people

1 service
sink per
floor

31-60

add 1

addl

add 1

61 -90

add 1

91 - 120

add 1

addl

ea. add'l. 60
over 120

addl

add 2

add 1

add 2

Factory and
Industrial

F-l and

F-2

Structures in which occupants are engaged in work
fabricating, assembling or processing products or materials.

See Notes: 4, 6, 9, 12, 16

1 - 10

1 per

people

1 emergency
shower per 10
people when
exposed to
skin
contamination

1 service
sink per
floor
1 emerg.
shower
and eye
wash

11-25

add 1

addO

add 1

26-50

addl

add 1

addl

51 -75

add 1

addO

add 1

76- 100

add 1

add 2

ea. add'l. 50 over
100

add 2

Table 7.21.1
MINIMUM NUMBER OF REQUIRED PLUMBING FIXTURES - Page 3

No.

Classification

Use
Group

Description

No. Of Persons of
Each Sex

Water Closets
(Urinals)

Lavatories

Drinking

Water

Facilities

Bath or
Shower

Other

Male

Female

Male

Female

Institutional

1-1

Six or more individuals in a supervised environment.
Group homes. Alcohol and drug centers, convalescent
facilities, hospital wards.

See Notes: 4, 16

1 - 8 patients

Vi of required
water closets

1 per

100

people

1 per
20 people

1 service
sink per
floor

ea. add'l. 8 over 8

add 1

addl

1-2

a) Buildings, with six or more individuals, used for
medical, surgical, psychiatric, nursing or custodial care.

b) Hospital rooms: private or semi-private.

I water closet per
patient room

1 per patient room

1 per

patient

room

1 service
sink per
floor

1-3

Buildings, with six or more persons under some restraint

or security:

a) Detention centers (short term).

See Notes: 4, 14,16

1 per cell or 1 per 4
inmates

1 per cell or
1 per 4 inmates

1 per 6
inmates

1 service
sink per
floor

b) Prisons, jails and reformatories (long term).
See Notes: 4, 14, 16

1 per cell or 1 per 8
inmates

I per cell or
1 per 8 inmates

1 per 15
inmates

1 service
sink per
floor

Mercantile

Buildings occupied for display and sales purposes. Retail
stores, service stations, shops, salesrooms, markets and
shopping centers.

See Notes: 2, 4, 6, 7, 12, 15, 16

1-50

1 per
1000
people

1 service
sink per
floor

51-150

add 1

addO

add 1

151-300

addO

add 1

addO

add 2

ea. add'l. 300
over 300

add 1

add 2

add 1

add 2

Table 7.21.1
MINIMUM NUMBER OF REQUIRED PLUMBING FIXTURES - Page 4

No.

Classification

Use
Group

Description

No. Of Persons
of Each Sex

Water Closets
(Urinals)

Lavatories

Drinking

Water

Facilities

Bath or
Shower

Other

Male

Female

Male

Female

Residential

R-l

a) Hotels, motels.

1 water closet per
guest room

1 per guest room

1 per guest
room

service
sink per
floor

b) Dormitories and boarding houses.
See Notes: 4, 6, 9, 10, 16

1 -20

1 per
100 or 1
per floor

ea. add'l.

20 add 1

service
sink per
floor 1
laundry
tray per
100

ea. add'l. 20 over
20

add 1

add 2

add 1

add 2

R-2

Multi-family dwellings.
See Note: 4, 10

1 water closet per unit

1 per unit

kitchen
sink per
unit 1
laundry
tray per
100

R-3
R-4

One and two-family dwellings,
Detached one and two-family dwellings

1 water closet per unit

1 per unit

kitchen
sink

Storage

S-l
S-2

Structures for the storage of goods, warehouses, storehouses
and freight depots. Moderate hazard.

Structures for the storage of goods, warehouses, storehouses
and freight depots. Low hazard.

See Notes: 1,4, 6, 18, 19

1 water closet per unit

1 per unit

service
sink per
unit

Utility and
Miscellaneous

U-l

Accessory buildings: Barns, carports, stables, sheds,
greenhouses.

No fixtures are
required

U-2

Construction workers

ANSI Z4.3
if non-sewered
waste disposal
equipment is used

•

Notes for Table 7.2 1.1:

1. This table shall be used unless superseded by the Building Code. For handicap requirements see local, state or national codes. Additional fixtures
may be required where environmental conditions or special activities may be encountered.

2. Drinking fountains are not required in restaurants or other food service establishments if drinking water service is available. Drinking water is not
required for customers where normal occupancy is short term. A kitchen or bar sink may be used for employee water drinking facilities.

3. In food preparation areas, fixture requirements may be dictated by local Health Codes.

| 4. Wherever both sexes are present in approximately equal numbers, multiple the total census by 50% to determine the number of persons of each sex
to be provided for. This regulation only applies when specific information, that would otherwise affect the fixture count is not provided.

5. Not more than 50% of the required number of water closets may be urinals.

6. In buildings with multiple floors, accessibility to the fixtures shall not exceed one vertical story.

7. Fixtures for public use as required by this section may be met by providing a centrally located facility accessible to several stores. The maximum distance
from entry to any store to this facility shall not exceed 500 feet.

8. In stores with floor areas of 150 sq. ft. or less, the requirements to provide facilities for use by employees may be met by providing central facilities
located accessible to several stores. The maximum distance from entry to any store from this facility shall not exceed 300 feet.

9. Fixtures accessible only to private offices shall not be counted to determine compliance with this section.

1 0. Multiple dwellings or boarding houses without public laundry rooms shall not require laundry trays.

1 1. (Reserved)

| 12. Requirements for employees and customers may be met with a single set of restrooms.

13. If the design number of customers in food handling establishments exceeds 100, separate facilities for employees and customers are required.

14. Water closet and lavatory may be a combination fixture. All showers and lavatories shall have thermostatic control and timing devices.

15. See Section 7.21.4 and Section 7.21.7 for toilet facilities for occupancies with a total floor area of 1,500 square feet or less.

1 6. 1.n determining the number of required fixtures for numbers of persons that fall in the "each additional (xx) over (xx)" listings, the requirement applies
to fractions of the listed group.

1 7. Laboratories in higher education facilities shall have safety showers.

1 8. Warehouse storage area requirements shall be permitted to be met by providing a facility centrally located within the storage area. The maximum
travel distance to the facility shall not exceed 500 feet.

1 9. Multiple individual self storage areas shall be permitted to be met by fixtures located in the facilities administration building. The administration office
must be accessible during normal business hours.

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•

1 92 2006 National Standard Plumbing Code-Illustrated

•

Chapter 8

Hangers and Supports

8.1 GENERAL

a. Hangers and anchors shall be securely attached to the building construction at sufficiently close intervals
to support the piping and its contents.

b. Fixtures, appliances and equipment shall be connected to support the weight of the device and any
additional probable loads that may impact on the device.

c. Fixtures shall be rigidly supported so that no strain is transmitted in the piping connections.

8.2 VEETICM* PIPING

a. Vertical pipe of the following materials shall be supported according to manufacturer's recommendations,
but no less than the distances listed below:

1 . Cast-iron soil pipe — at base and at each story height.

2. Steel threaded pipe — at every other story height.

3. Copper tube— at each story height butnot more than 10-foot intervals.

4. Lead pipe — four-foot intervals.

5. Plastic pipe — see Section 8.7.

6. Flexible plastic tubing — each story height and at mid-story.

7. Stainless steel drainage pipe — at each story height.

8.3 HORIZONTAL PIPING

a. Horizontal pipe of the following materials shall be supported according to manufacturer's recommenda-
tions, but not less than the distances listed below:

1 . Cast-iron soil pipe — minimum of one hanger per pipe length located within 1 8 inches of each joint (up to
1 0-foot maximum pipe length), at changes in direction, and at branch connections. Where pipe is suspended by
non-rigid hangers more than 1 8 inches long, provide lateral support at 25-foot maximum spacing. Lateral
support shall consist of either 1 ) a sway brace or 2) either a change in direction or a branch connection that
provides the required lateral support.

2. Steel threaded pipe — 3/4-inch size and smaller — 1 0-foot intervals. One-inch size and larger — 1 2-foot
intervals.

3. Copper tube (1-1/4 inch size and smaller) — 6-foot intervals.

4. Copper tube (1-1/2 inch size and larger) — -10-foot intervals.

5. Lead pipe — on continuous metal or wood strips for its entire length.

6. Plastic pipe — see Section 8.7.

7. Flexible plastic tubing — 32 inches.

8. Stainless steel drainage pipe— 10 foot intervals, changes of direction and branch connections.

2006 National Slumlord Plumbing Code-tthisnutei!

J 93

8.4 MATERIAL

a. Hangers, anchors, and supports shall be of metal or other material of sufficient strength to support the
piping and its contents.

b. Piers shall be of concrete, brick, or other masonry construction.

8.5 STRAIN AND STRESSES IN PIPE

Piping in the plumbing system shall be installed so as to prevent strains and stresses that will exceed the
structural strength of the pipe. Provision shall be made for expansion and contraction of the piping. (See
Sections 4. 1 .3 and 4.2. 1 6.) See Figures 8.5-A through-C

PIPE HANGER
OR SUPPORT

ANCHOR

^ GUIDES TO ALLOW FREE
\ LINEAR MOVEMENT /

SUFFICIENT
LENGTH TO
ALLOW FOR
EXPANSION

GUIDES T0 AL LOW FREE
\ LINEAR MOVEMENT /

■ ANCHOR

ANCHOR

CTL

PLAN VIEW

Figure 8.5 - A
AN EXPANSION LOOP IN A HOT WATER PIPE LINE

r- GUIDES TO ALLOW FREE -7
\ LINEAR MOVEMENT /

* — fri — fHTl — f

V GUIDES TO ALLOW FREE -7
LINEAR MOVEMENT /

ANCHOR

MECHANICAL EXPANSION JOINT
(SLIP JOINT TYPE)

Figure 8.5 - B
AN EXPANSION COMPENSATOR IN A HOT WATER PIPE LINE

194

2006 Naiioiittl Sicifidant Plumbing Coite-Wusiraied

•

GUIDES

\— IjUIUtti —j

GUIDES

ANCHOR

y- ijuiutt* —7

ANCHOR

CORRUGATED TUBING

WITH BRAIDED METAL JACKET

SUPPORT LOOP (IF HORIZONTAL)

Figure 8.5 - C
A FLEXIBLE EXPANSION LOOP TO ABSORB THERMAL EXPANSION

8.6 BASE OF STACKS

Bases of cast-iron stacks shall be supported on concrete, brick laid in cement mortar, metal brackets attached
to the building construction, or by other methods approved by the Authority Having Jurisdiction. Other piping
material shall be so anchored as to support the stack at the base.

. / iSUrrUKI Or rJLAMIC JrlrL

Hangers and straps shall not compress, distort, cut or abrade the piping and shall allow free movement of the
pipe. Restraining joints and expansion joints shall be installed as required. Pipe shall be supported at intervals of
not more than four feet, at end of branches, and at a change of direction or elevation. Supports shall allow free
movement. Vertical piping shall be maintained in straight alignment. Trap arms in excess of three feet shall be
supported as close as possible to the trap. Installation shall be in accordance with appropriate standards and
manufacturer's instructions.

8.8 UNDERGROUND INSTALLATION

See Section 2.6.

8.9 SEISMIC SUPPORTS FOR PIPING

Where earthquake loads are applicable in accordance with the adopted building code, plumbing piping sup-
ports shall be designed and installed for the seismic forces in accordance with the adopted building code.

2006 Na\\unai Standard Plumbing Codi'-Musiraietl

195

Blank Page

J 96 200b National Standard Plumbing Code-Hlumraieil

•

Chapter 9

Indirect Waste Piping and Special Wastes

9.1 INDIRECT WASTES

9.1.1 General

Drains from fixtures, fixture compartments, equipment, appliances, appurtenances, and other devices
requiring-protection against contamination from backflow or flooding from the drainage system or other
source shall not be directly connected to any soil, waste, or vent pipe. Such drains shall discharge sepa-
rately through an air gap or, where permitted, an air break.

9.1.2 Air Gaps

The clear air gap between a drain outlet or indirect waste pipe and the flood level rim of an indirect waste
receptor or other point of disposal shall be not less than twice the diameter of the effective opening of the
drain served, but not less than one inch.

9.1.3 Air Breaks

Where air breaks are permitted, the waste pipe shall be permitted to terminate below the Hood level rim
of the receptor but shall maintain an air space above the top of the receptor's trap seal. Such indirect
waste pipes shall be permitted to connect to the inlet side of the receptor's trap.

9.1 .4 Where Indirect Wastes Are Required

Indirect wastes shall be provided for food-handling or food-storage equipment, medical or other sterile
equipment, clear-water wastes or discharges, and other drains as required herein.

9.1.5 Food Handling Areas

a. Fixtures and appliances used for the storage, processing, preparation, serving, dispensing, or sale of
food shall be drained indirectly. Examples of such fixtures include refrigerated cases, steam kettles, steam
tables, potato peelers, egg boilers, coffee urns and brewers, culinary sinks used for soaking or washing
food, ice machines, ice storage bins, drink dispensers, and similar equipment or appliances. A separate
indirect waste pipe shall be provided for each fixture drain and each shall discharge separately through an
air gap or air break into a trapped and vented receptor.

b. Where bar sinks, glass-washing sinks, or other counter sinks cannot be vented according to the
requirements of Chapter 12, they shall be permitted to each discharge separately to a trapped and vented
receptor through indirect waste pipes providing either an air break or air gap. See Figures 9.1.5 - A
through - C

2006 National Siaiu/urJ Plumbing CoJe-IUustnned

197

CULINARY SINK

INLET

CULINARY SINK

OCT

tsi'cz;

AIR BREAK OR' \ " I — RECEPTOR
AIR GAP S -7

pi Wj

AIR GAF FITTING
LOCATE AS CLOSE TO
THE FIXTURE AS POSSIBLE

A. MULTIPLE COMPARTMENT S1NKS-

INDIRECT WASTE REQUIRED FOR
FOOD PREPARATION SINKS

OUTLET

VENTED FLOOR SINK

-v

B. COMMERCIAL DISHWASHER ARRANGEMENT- AIR BREAK

IT-

VENTED FLOOR SINK
I

AIR GAP IS REQUIRED
FOR ICE MAKER

C. ICEMAK1NG MACHINE

Figure 9 J .5- A
FNDIRCT WASTE PIPING IN A FOOD HANDLING AREA

SODA
DISPENSER

BAR SINK

' i J '

VENT-

AtR GAP SHOWN
(CAN BE AIR BREAK)

FLOOR SINK -

WASTE ■

Figure 9.1.5 - B
INDIRECT WASTES FOR COUNTER SINKS AND COUNTER-MOUNTED EQUIPMENT

198

2006 National Standard Phtmbtits Code-illustrated

FOOD PREP OR

DISHWASHING

SINK

FLOOR DRAIN

SOIL OR WASTE
STACK

-NOTES:

1. If there is a stoppage in the soil or waste stack, the sewage will overflow from the floor drain
before it backs up into the food prep or dishwashing sink.

Figure 9 J.5-C

PROTECTING A FOOD PREP OR

DISHWASHING SINK FROM SEWAGE BACKUP

EXCEPTIONS:

(1) Indirect drains shall not be required for domestic kitchen sinks or domestic dishwashers.

(2) The rinsing and sanitizing compartments of three-compartaient commercial sinks shall be drained
indirectly, in accordance with Section 9.1 .1, but the pot washing compartment shall discharge to the
drainage system through a grease interceptor in accordance with Section 6. 1.1.

(3) If a properly vented floor drain is installed immediately adjacent to a sink used for dishwashing, a
properly trapped and vented sink or sink compartment shall be permitted to connect directly to the drain-
age system, on the sewer side of the floor drain trap.

9.1 .6 Walk-in Coolers and Freezers

a. If floor drains are located in walk-in coolers or walk-in freezers used for the storage of food or other
products for human consumption, they shall be indirectly connected to the sanitary drainage system.

b. Separate indirect waste pipes shall be provided for the floor drains from each cooler or freezer, and
each shall discharge separately through an air gap or air break into a trapped and vented receptor.

c. Traps shall be provided in the indirect waste pipe when required under Section 9.2.3.

d Indirectly connected floor drains may be located in freezers or other spaces where freezing tempera-
tures are maintained, provided that traps are not required under Section 9.2.3. Otherwise, the floor of the
freezer shall be sloped to a floor drain located outside the storage compartment,
e. The above requirements do not apply to refrigerated food preparation areas or work rooms.

9T.7 Medical and OtherSterileEquipment

Stills, sterilizers, and other sterile equipment requiring drainage shall each discharge separately through an
air gap into a trapped and vented receptor.

•

200f> National Standard Ptimtbmp Code-UhtSirated

199

9.1.8 Potable Clear-Water Wastes

Discharges of potable water from the water distribution system, water storage or pressure tanks, water
heaters, water pumps, water treatment equipment, boilers, relief valves, backflow prevention devices, and
other potable water sources shall be indirect through an air gap.

EXCEPTION: An air break shall be permitted where the potable water supply to boilers, water-cooled
equipment, heating and air-conditioning systems, and similar cross-connections is protected by a backflow
prevention device in accordance with Section 1 0.5.

9.1.9 Drinking Fountains and Water Coolers

Drinking fountains and water coolers shall be permitted to discharge indirectly through an air break or air
gap. Where such fixtures are connected to a dedicated drainage stack, the fixtures may connect directly
to the stack and the stack shall terminate with an air break or air gap.

9.1 .1 Air Conditioning Equipment

Where condensate or other drainage from air conditioning or cooling equipment discharges to a drainage
system, it shall discharge indirectly to a trapped and vented receptor through an air break or air gap.
EXCEPTION: An air break shall not be permitted where the drain connects to a point in the air condition-
ing equipment that operates at a pressure below atmospheric.
See Figure 9.1.10

DIRECTION OF AIR FLOW

COOLING COIL-

-AIR CONDITIONING UNIT

-CONDENSATE PAN (SHOWN UNDER NEGATIVE PRESSURE)

TRAP REQUIRED-

AIR GAP SHOWN - AIR BREAK
IS ACCEPTABLE IF PRESSURE
OF CONDENSATE DRAINAGE
FROM APPLIANCE IS POSITIVE

Figure 9.1.10
DRAINING AIR CONDITIONING CONDENSATE

9.1.11 Swimming Pools

Drainage from swimming pools or wading pools, including pool drains, filter backwash, overflows, and
pool deck drains, shall discharge indirectly through an air gap to a trapped and vented receptor.

9.1.12 Relief Valve Discharge Piping

Discharge piping from relief valves and any associated indirect waste piping shall be in accordance with
Section 10. 16.6.

200

2006 National Shtndur J Plumbing Code-Uhmmied

•

9.2 INDIRECT WASTE PIPING

9.2.1 Materials and Installation

Indirect waste piping shall be of materials approved for sanitary drainage under Section 3.5.

9.2.2 Pipe Size

Indirect waste piping shall be not less than the nominal size of the drain outlet on the fixture or equipment
served.

9.2.3 Fixture Traps

Traps shall be provided at fixtures and equipment connections where the developed length of indirect

waste piping exceeds ten feet.

EXCEPTION: Drain lines used for clear-water wastes.

9.2.4 Provisions for Cleaning

Indirect waste piping shall be installed in a manner to permit ready access for flushing and cleaning.
Where necessary, cleanouts shall be provided in accordance with Section 5.4.

9.3 INDIRECT WASTE RECEPTORS

9.3.1 General

a. Receptors for indirect wastes shall be properly trapped and vented floor drains, floor sinks,
standpipes, open-hub drains, air gap fittings, or other approved fixtures.

b. Receptors shall be of such size, shape, and capacity as required to prevent splashing or flooding by
the discharge from any and all indirect waste pipes served by the receptor.

c. Plumbing fixtures that are used for domestic or culinary purposes shall not be used as receptors for
indirect wastes, except as follows:

EXCEPTIONS:

( 1 ) In a dwelling unit, a kitchen sink trap, or food waste grinder, shall be permitted to receive the
discharge from a dishwasher.

(2) In a dwelling unit, a laundry sink, provided that an air gap is maintained for any potable clear- water
waste, shall be an acceptable receptor for:

a. Air conditioning condensate.

b. Automatic clothes washer.

c. Water treatment unit.

d. Water heater relief valve discharge.

(3) A service sink or mop basin shall be an acceptable receptor for air conditioning condensate and
any infrequent potable clear-water waste if the required air gap is provided for potable clear-water
wastes.

See Figures 7.15.2, 7.15.3, 7.15.4, 9.1.5-A, 9.1.5-B, and 9.1.10

9.3.2 Strainers or Baskets

Floor sinks and floor drains that handle other than clear-water wastes shall include an internal or a readily
removable metal basket to retain solids. See Figure 9.3.2

2006 National Standard Plumbing Codt-IUiistruted 201

ooooooooooo
ooooooooooo

.OOOOOOOOOOQ

ooooooooo
ooooooooo

REMOVABLE BASKET

OPTIONAL FLAT BOTTOM STRAINER

RECEPTOR

WITH

DOMED BOTTOM

STRAINER

RECEPTOR

WITH

REMOVABLE

BASKET

NOTES:

1. Receptors may have a partially open top grate.

2. Domed bottom strainers help to reduce splashing.

3. In the receptor with a basket, the optional flat bottom strainer protects the drain line while the
basket is removed.

Figure 9.3.2
FLOOR SINKS WITH STRAINER OR BASKET

9.3.3 Prohibited Locations

Receptors for indirect wastes shall not be located in a toilet room or in any confined, concealed, inacces-
sible, or im ventilated space.

EXCEPTION: Air conditioning condensate in dwellings shall be permitted to drain to a tub waste and
overflow or lavatory tailpiece in accordance with Section 9.4. 3. c. 5.

9.3.4 Standpipes

A standpipe, 2-inch minimum pipe size and extending not more than 48 inches nor less than 1 8 inches
above its trap, shall be permitted to serve as a receptor for a domestic clothes washer. In a dwelling, a
laundry sink shall be permitted to drain into the standpipe. See Figure 9.3.4

202

2006 National Standard Plumbing Cixle-lttmti tiled

•

W OR 1/ 2 "
VENT

2" MIN. DRAIN

BETWEEN 18" AND 48"

MIN. TRAP

STANDPIPE FOR
DOMESTIC CLOTHES WASHER

STANDPIPE FOR
FLOOR DRAIN

VENT

LAUNDRY TRAY AND

CLOTHES WASHER DRAIN

(SINGLE FAMILY DWELLINGS ONLY)

NOTES;

1. Standpipes shorter than 18" may cause splashing and overflow.

2. Standpipes taller than 48" may cause the trap to self-siphon. They may also retain waste
particles and create an odor problem.

Figure 9.3,4
STANDPIPE RECEPTORS

9.3.5 Open-hubDrains

A trapped and vented open-end drain pipe extending not less than 2 inches above the surrounding floor
shall be permitted to serve as a receptor for clear-water wastes.

9.3.6 Minimum Receptor Pipe Size

a. The minimum dram pipe size for an indirect waste receptor shall be at least one pipe size larger than
the indirect waste pipe that it serves.

EXCEPTION: A laundry sink receiving the discharge from an automatic clothes washer under Section
9.3.1.b.2.

b. Where a receptor receives indirect drainage from two or more fixtures, the cross-sectional area of the
receptor drain shall be not less than the aggregate cross-sectional area of all indirect waste pipes served
by the receptor. For the purposes of this requirement, l-l/4"pipe= 1.2 in 2 , 1-1/2" pipe = 1,8 nr,2"pipe
= 3.1 in 2 , 2-1/2" pipe = 4.9 in 2 , 3" pipe - 7.1 in 2 , 4" pipe = 12.6 in 2 , 5" pipe == 19.6 in 2 , and 6" pipe =
28.3 in 2 . See Figure 9.3.6

2006 National Stamford Plumhins Code- ft fust rated

203

1 1«

• 2

a J»

' 2

1 2

NOTES:

1. The aggregate cross-sectional area of three 1-1/2" indirect waste pipes is 3 x 1.8 = 5.4 square
inches. A 2" outlet size is only 3.1 square inches. The minimum receptor outlet pipe size is 3"
with 7.1 square inches.

Figure 9.3.6
MINIMUM RECEPTOR OUTLET PIPE SIZE

9.3.7 Drainage Fixture Unit (0FU) Values

The drainage fixture unit values used to combine the loading of indirect waste receptors with other
fixtures shall be the sum of the DFU values for all fixtures that are indirectly drained into the receptor.

9.4 SPECIAL WASTES

9.4.1 Treatment of Corrosive Wastes

Corrosive liquids, spent acids, or other harmful chemicals that may damage a drain, sewer, soil or waste
pipe, create noxious or toxic fumes, or interfere with sewage treatment processes shall not be discharged
into the plumbing system without being thoroughly neutralized or treated by passing through a properly
constructed and approved neutralizing device. Such devices shall be provided automatically with a suffi-
cient supply of neutralizing medium, so as to make its contents non-injurious before discharge into the
drainage system. The nature of the corrosive or harmful waste and proposed method of its treatment shall
be submitted to and approved by the Authority Having Jurisdiction prior to installation. See Figures
9.4.1 and 1.2.55

204

2006 National Standard Plumbing Cudc-lUwiiralml

VENT

FLOOR LINE

r ;

£ — r

HARMFUL
CHEMICALS

S2L

^SENSOR WIRE
y/ y- SOLENOID VALVE

■*=

■POTABLE WATER

VACUUM BREAKER (APPROVED TYPE)
ASPIRATOR

NEUTRALIZING
SOLUTION

OUTLET FLOW

TREATMENT
TANK

NOTES:

1. The automatic system can neutralize acids or caustic, depending on what neutralizing solution

is used. If the system had two chemical feeders, it could neutralize both acid and caustic

wastes.

Figure 9,4.1
AN AUTOMATIC WASTE TREATMENT NEUTRALIZING TANK

9.4.2 High Temperature Wastes

No waste at temperatures above 140°F shall be discharged directly into any part of a drainage system.
Such wastes shall be discharged to an indirect waste receptor and a means of cooling shall be provided
where necessary.

9.4.3 Air Conditioning Condensate

a. Indirect waste piping from air conditioning units shall be sized according to the condensate-generating
capacity of the units served. Branches from individual units shall be no smaller than the drain opening or
drain connection on the unit. Traps shall be provided at each air conditioning unit or cooling coil to main-
tain atmospheric pressure in the waste piping.

b. Condensate waste piping shall be sloped not less than 1/8" per foot. Drainage fittings shall be used in
sizes 1 - 1 /4" and larger. Minimum pipe sizing shall be as follows:

3/4" pipe size through 3-ton cooling capacity
1 " pipe size through 20-ton cooling capacity

2006 ,\ ! uiioiici! Standard Plumbing Cwle-Hlustnucc)

205

1 -1/4" pipe size through 1 00-ton cooling capacity

1 - 1 /2 " pipe size through 300- ton cooling capacity

2" size pipe through 600-ton cooling capacity
c. Discharge of air conditioning condensate shall not be permitted to create a nuisance such as by flowing
across the ground or paved surfaces. Unless expressly prohibited by the Authority Having Jurisdiction,
the point of indirect discharge for air conditioning condensate shall be one of the following:

1 . The building sanitary drainage system.

2. The building storm drainage system.

3 . A sump pump.

4. A subsurface absorption pit or trench.

5 . Within dwellings, a tub waste and overflow or lavatory tailpiece within the same dwelling.
See Figure 9.4.3-A and-B

.3/4:

r min.

3 TONS = 3/4" MIN.

. r MIN.

6 TONS = 1" MIN.-

9 TONS = 1" MIN.

3
TONS

3/4"

-3

3
TONS

3/4"

. * MIN.

■vT

3
TONS

TO POINT
OF DISPOSAL

NOTES:

1. The condensate drain traps on air conditioning (cooling) units must have sufficient trap seal
depth to offset the static pressure (positive or negative) at the condensate drain connection of
(he unit. The traps are shown with a seal depth for a negative pressure

Figure 9.4.3 - A
SIZING INDIRECT WASTE PIPING FOR AIR CONDITIONING CONDENSATE

206

2006 National Standard Plumbing Co<h'-J!h<W(iiett

AIR

CONDITIONING

UNIT

TO POINT

OF DISCHARGE

TO A RECEPTOR

TO POINT OF .

DISCHARGE T "IVT

FULL PORT
SHUTOFF VALVE

CHECK VALVE

TO A SUMP PUMP

fNQ

THERMOSTAT

ACCESSIBLE

■TO OCCUPANT

LAVATORY

EXAMPLES OF LAVATORY OR

BATHTUB CONDENSATE

CONNECTIONS

BRANCH WYE FITTING

CONDENSATE
PIPING

OVERFLOW TAPPED
TO RECIEVE
CONDENSATE PIPING

Figure 9.4.3 - B
DISCHARGING AIR CONDITIONING CONDENSATE

2006 Nasi omit Standard Plumbing Code-flfnstrnied

207

Blank Page

208 2006 National Slumlord Plumbing CrxIc-llluMmleJ

Chapter 10

Water Supply and Distribution

10.1 QUALITY OF WATER SUPPLY

Only potable water shall be supplied to plumbing fixtures used for drinking, bathing, culinary use or the processing
of food, medical or pharmaceutical products.

10.2 IDENTIFICATION OF POTABLE AND NON-POTABLE WATER

In buildings where dual water distribution systems are installed, one potable water and the other non-potable water,
each system shall be identified either by color marking or metal tags, or other appropriate methods such as may be
approved by the Authority Having Jurisdiction. Each outlet on the non-potable water line that may be used for
drinking or domestic purposes shall be posted: DANGER-UNSAFE WATER. See Figure 10.2

SERVICE AND BACKGROUND COLOR

Potable Water = GREEN
Non-Potable Water = YELLOW
Cold Water Supply = GREEN
Hot Water Supply = YELLOW
Hot Water Return = YELLOW
Sanitary Drain = GREEN
Plumbing Vent = GREEN
Waste = GREEN
Waste (corrosive) = YELLOW
Storm Drain = GREEN
Roof Drain = GREEN
Fire Protection = RED

NOTES:

1. Color coding of piping is based on ANSI A13.1 - Scheme for the Identification of Piping Systems.

Figure 10.2
COLOR CODING FOR PIPING

2006 National Standard Plumbing Code-Illustrated

209

10.3 WATER REQUIRED

10.3.1 Buildings

Plumbing fixtures shall be provided with a potable supply of water in the amounts and at the pressures
specified in this Chapter.

10.4 PROTECTION OF POTABLE WATER SUPPLY

10.4.1 General

A potable water supply shall be designed, installed and maintained to prevent contamination from non-potable
liquids, solids or gases by cross connections.

10.4.2 Interconnections

Interconnections between two or more public water supplies shall be permitted only with the approval of the
Authority Having Jiuisdicti on.

10.4.3 Cross Connection Control

Potable water supplies shall be protected in accordance with the cross connection control program of the
Authority Having Jurisdiction and the provisions of this Code. Cross connection control shall be provided at
individual outlets, and where required, by containment of the premises. Each potential cross connection within
the premises shall be protected. Where containment is required, the potable water supply shall be protected
by a backflow protection device installed immediately downstream of the meter or between the service
shutoff valve and the first outlet or branch connection. See Figures 10.4.3 - A and - B

FAUCET
VACUUM BREAKER

RUBBER HOSE
MOP SINK

FINISHED FLOOR

\Z\

URINAL

BATHTUB

MOP SINK

NOTES;

1 . Individual outlet protection is required by this Code. It protects the potable water distribution
piping from being contaminated by a cross connection within the property.

Figure 10.4.3 - A
CROSS CONNECTION CONTROL BY INDIVIDUAL OUTLET PROTECTION

210

200b National Slumlord Plumbing Code-lllmtmictl

•

BACKFLOW PREVENTION DEVICE
TO CONTAIN BACKFLOWS TO
WITHIN THE PROPERTY

PUBLIC WATER
MAIN -~

BUILDING WATER SERVICE

BUILDING SERVICE
SHUTOFF VALVE —

NOTES:

1. Cross connection control by containment protects the public water supply from being contaminated
by a cross connection within a customer's property.

Figure 10.4.3 - B
CROSS CONNECTION CONTROL BY CONTAINMENT OF THE BUILDING

10,4.4 Private Supplies

a. Private potable water supplies (i.e., wells, cisterns, lakes, streams) shall require the same backflow
protection that is required for a public potable water supply.

b. Cross connection between a private potable water supply and a public potable water supply shall not be
made unless specifically approved by the Authority Having Jurisdiction.

Comment: Interconnections between private water supplies and public water supplies are generally
prohibited because private supplies are usually not monitored continuously for water quality.

•

10.4.5 Toxic Materials

a. Piping conveying potable water shall be constructed of non-toxic material.

b. The interior surface of a potable water tank shall not be lined, painted, or repaired with any material that
will affect either the taste, odor, color or potability of the water supply when the tank is placed in or returned
to service.

Comment: The toxicity rating of a piping material can be found in the material standard listed in Table
3 J. 3, The piping materials fisted in Table 3.4 are non-toxic and are suitable for conveying potable
water.

10.4.6 Reserved

10.4.7 Reserved

10.4.8 Used Materials

Materials that have been used for any purpose other than conveying potable water shall not be used for
conveying potable water.

2006 Ntiitomt! Standard Plumbing Code-Musi raied

211

1 0.4.9 Water As a Heat-Transfer Fluid

Potable water may be used as a heat-transfer fluid provided the system design is approved by the Authority
Having Jurisdiction.

10.5 BACKFLOW PREVENTION

10.5.1 Plumbing Fixtures, Appliances, Water Supply Outlets

The water supply shall be protected from back-siphonage by a fixed air gap between the potable water outlet
and the overflow level of the fixture or receptor.

10.5.2 Requirements for Air Gaps

a. How Measured: The air gap shall be measured vertically from the lowest end of a potable water outlet
to the flood rim or line of the fixture or receptor into which it discharges.

b. Minimum Size (distance): The minimum required air gap shall be twice the effective opening of a potable
water outlet unless the outlet is a distance less than 3 times the effective opening away from a wall or similar
vertical surface in which case the minimum required air gap shall be 3 times the effective opening of the
outlet. In no case shall the minimum required air gap be less than that shown in Table 10.5.2. See Figure
10.5.2

Table 10.5.2
MINIMUM AIR GAPS FOR PLUMBING FIXTURES

Minimum Air Gap

Fixture

When not Affected

By Near Wall'

(Inches)

Effective openings greater than one inch

When Affected

By Near \Vall :

(Inches)

Lavatories with effective opening not

]

1-1/2

greater than 1/2 inch diameter

Sink, laundry' trays, goose-neck bath faucets and other fixtures

1-1/2

2-1/4

with effective openings not greater than 3/4" diameter

Over rim bath fillers and other fixtures with

effective openings not greater than 1 inch diameter

Drinking water fountains-single orifice not greater than 7/1 6

1-1/2

(0.437) in. diameter or multiple orifices having total area of

0.1 50 square inches (area of circle 7/16 in. diameter)

2X 3X

diameter of diameter of

effective opening effective opening

1 . Side walls, ribs or similar obstructions do not affect air gaps when spaced from inside edge of the spout opening a distance greater than
three times the diameter of the effective opening for a single wall, or a distance greater than four times the diameter of the effective opening foT
two intersecting walls.

2. Vertical walls, ribs, or similar obstructions extending from the water surface to or above the horizontal plane of the spout opening require
a greater air gap when spaced closer to the nearest inside edge of the spout opening than specified in I^ote 1 . above. The effect of three or more
such vertical walls or ribs has not been determined. In such cases, the air gap shall be measured from the top of the wall.

212

2006 ■Naiiomit Slunduid Plumbing Cotle-ZIIuiiKiieil

•

AIR GAP - 2 TIMES THE DIAMETER "D"
BUT NOT LESS THAN 1"

ORIFICE OPENING - DiAMETER "D"

TYPICAL LAVATORY FAUCET - AIR GAP

AIR GAP -
2 TIMES THE
DIAMETER "D"
BUT NOT
LESS THAN 2"

d— H (—

TYPICAL TUB FILLER - AIR GAP

NOTES:

1. Diameter "d" is the opening on the faucet aerator, tub spout, or outlet pipe

•

Figure 10.5.2
MINIMUM REQUIRED AIR GAPS

1 0,5.3 Required Backflow Prevention Devices

The following requirements shall apply:

A. Backsiphonage. Non-Continuous Pressure, Non-Health Hazard

1 . Atmospheric vacuum breaker - ASSE 1 001 (AVB)

2. Hose connection vacuum breaker - ASSE 1011

3. Any backflow protection device approved for protection against backsiphonage with non-
continuous or continuous pressure and a non-health hazard or health hazard.

B. Backsiphonage. Continuous Pressure, Non-Health Hazard

1. Pressure vacuum breaker - ASSE 1020 (PVB)

2. Spill-resistant vacuum breaker - ASSE 1056 (SVB)

3. Backflow preventer with intermediate atmospheric port - ASSE 1012

4. Double check valve assembly ASSE 1015 (DC and DCVA)

5. Any backflow protection device approved for protection against backsiphonage with continu-
ous pressure and a non-health hazard or health hazard.

C. Backsiphonage, Non-Continuous Pressure, Health Hazard

1. Atmospheric vacuum breaker - ASSE 1001 (AVB)

2. Hose connection backflow preventer - ASSE 1052

3. Any backflow protection device approved for protection against backsiphonage with non-
continuous or continuous pressure and a health hazard.

2006 National Siandurd Plumbin? CoJc-lUusinued

213

D. Backsiphonage, Continuous Pressure, Health Hazard

1 . Pressure vacuum breaker - ASSE 1020 (PVB)

2. Spill-resistant vacuum breaker - ASSE 1056 (SVB)

3. Reduced pressure backflow preventer assembly - ASSE 1013 (RP, RPZ, and RPBA)

4. Any backflow protection device approved for protection against backsiphonage with continuous
pressure and a health hazard.

E. Back Pressure. Non-Health Hazard

1. Dual check backflow preventer - ASSE -1024 (DuCh)

2. Double check valve assembly - ASSE 1015 (DC)(DCVA)

3. Reduced pressure backflow preventer assembly - ASSE 1013 (RP)(RPZ)(RPBA)

F. Back Pressure, Health Hazard

1 . Reduced pressure backflow preventer assembly - ASSE 1013 (RP)(RPZ)(RPBA)

10.5.4 Approval of Devices

Backflow prevention devices shall be listed or certified by a recognized certification body as complying with
the appropriate standards in Table 3.1 .3 - Part IX.

1 0.5.5 Installation of Backflow Preventers

a. Devices of All Types: All backflow prevention devices shall be accessible. Backflow prevention devices
having atmospheric vents shall not be installed in pits, vaults, or similar potentially submerged locations.
Vacuum breakers and other devices with vents to atmosphere shall not be located within fume hoods.

b. Atmospheric Vacuum Breakers: Pipe applied atmospheric vacuum breakers shall be installed with the
critical level at least six inches above the flood level rim or highest point of discharge of the fixture being
served. Approved deck-mounted and pipe-applied vacuum breakers and vacuum breakers within equipment,
machinery and fixtures where the critical level is a specified distance above the source of contanination shall
be installed in accordance with manufacturer's instructions with the critical level not less than one inch above
the flood level rim. Such devices shall be installed on the discharge side of the last control valve to the fixture
and no shut-off valve or faucet shall be installed downstream of the vacuum breaker. Vacuum breakers on
urinals shall be installed with the critical level six inches above the flood level rim.

See Figures 10.5.5 - A through - F. Also Figures 10.5.10 - A through - C

c. Pressure Type Vacuum Breakers: Pressure type vacuum breakers shall be installed with the critical level
at a height of at least 12 inches above the flood level rim for ASSE 1020 devices and with the critical level at
least six inches above the flood level rim or highest point of discharge of the fixture being served for ASSE
1056 devices. Deck -mounted and pipe-applied pressure type (ASSE 1056) vacuum breakers within equip-
ment, machinery and fixtures where the critical level is a specified distance above the source of contamina-
tion shall be installed in accordance with manufacturer's instructions with the critical level not less than one
inch above the flood level rim. See Figure 10.5.5 - G. Also Figures 10.5.10 - D and - E

d. Double Check Valves and Reduced Pressure Principle Valves: Such devices shall be installed at not less
than 12 inches above the floor or permanent platform with the maximum of 60 inches above floor or perma-
nent platform. See Figures 10.5.5 - H and - 1. Also 10.5.10 - F

e. Spill-resistane Vacuum Breakers: Approved deck mounted and pipe-applied spill-resistant vacuum
breakers within equipment, machinery and fixtures where the critical level is a specified distance above the
source of contamination shall be installed in accordance with manufacturer's instructions with the critical level
not less than one inch above the flood level rim.

214 200b National Standard Plwnbmt> Code-Illustrated

ATMOSPHERIC VACUUM BREAKER
ACCESSIBLE

6" MINIMUM FROM C-L
TO FLOOD RIM LEVEL

ON-OFF SWITCH

NOTES:

1. If the critical level (C-L) is not marked on the vacuum breaker body, the bottom of the valve is
considered to be the C-L reference,

2. Atmospheric vacuum breakers are not rated for periods of more than 12 hours of continuous water
pressure.

Figure 10,5.5 - A

THE POTABLE WATER SUPPLY TO A COMMERCIAL FOOD WASTE GRINDER

PROTECTED BY AN ATMOSPHERIC VACUUM BREAKER

ATMOSPHERIC /•

VACUUM BREAKER J

POTENTIALLY SUBMERGED HOSE

NOTES:

1. Atmospheric vacuum breakers are not rated for periods of more than 12 hours of continuous water
pressure.

Figure 10.5.5 - B
THE POTABLE WATER SUPPLY TO A SERVICE SINK
PROTECTED BY AN ATMOSPHERIC VACUUM BREA

2006 National Standard Plumbing Cadi'-lltustrated

215

ATMOSPHERIC
VACUUM BREAKER

POTENTIALLY SUBMERGED HOSE

NOTES:

1 . Atmospheric vacuum breakers are not rated for periods of more than 12 hours under continuous
water pressure.

Figure 10.5.5 - C

THE POTABLE WATER SUPPLY TO A LAB SINK

PROTECTED BY AN ATMOSPHERIC VACUUM BREAKER

6" MIN.
CRITICAL LEVE

ATMOSPHERIC VACUUM BREAKER

ASPIRATOR

VACUUM HOSE

SUCTION DEVICE

NOTES:

1 . Atmospheric vacuum breakers are not rated for periods of more than 1 2 hours under continuous
water pressure.

Figure 10.5.5 -D

THE POTABLE WATER SUPPLY TO AN ASPIRATING DEVICE

PROTECTED BY AN ATMOSPHERIC VACUUM BREAKER

216

2006 National Standard Pluinhuif! Code- illustrated

FLUSHOMETER
VALVE

ATMOSPHERIC
VACUUM BREAKER

CRITICAL LEVEL MARKING

NOTES:

1. Atmospheric vacuum breakers are not rated for periods of more than 1 2 hours under continuous
water pressure.

Figure 10,5,5 - E

THE POTABLE WATER SUPPLY TO A WATER CLOSET OR URINAL

PROTECTED BY AN ATMOSPHERIC VACUUM BREAKER

CRITICAL LEVEL
1" ABOVE
OVERFLOW

ANTI-SIPHON BALICOCK WITH
INTERGRAL VACUUM BREAKER

WATER SUPPLY

REFILL TUBE |

^-OVERFLOW TUBE

FILL TUBE

FLAPPER

FLUSH VALVE

: ^=£

FLUSH VALVE ASSEMBLY

Figure 10.5.5 - F

THE POTABLE WATER SUPPLY TO A WATER CLOSET GRAVITY FLUSH TANK

PROTECTED BY AN ANTI-SIPHON BALLCOCK WITH INTEGRAL VACUUM BREAKER

2006 National Standard Plumbing CoJt'-ltfiistrutetl

217

ASSE 1020 ANTI-SIPHON
PRESSURE VACUUM BREAKEF

SEE NOTES 1 & 4

TO OTHER FIXTURES
REQUIRING POTABLE WATER

SEE NOTE 3

4.^—- POTABLE WATER SUPPLY

NOTES:

1. ASSE 1020 anti-siphon pressure vacuum breakers can be located where subjected to continuous pressure.

2. The critical level (C-L) of the vacuum breaker must be at least 12" higher than the highest downstream piping.

3. Shutoff valves are permitted downstream from pressure vacuum breakers.

A. ASSE 1020 pressure vacuum breakers should not be located where water spillage from the atmospheric

vent will cause damage or create a nuisance. If necessary, use ASSE 1056 spill-resistant vacuum breakers.

Figure 10.5.5 - G

THE POTABLE WATER SUPPLY TO INDUSTRIAL PROCESS EQUIPMENT

PROTECTED BY AN ANTI-SIPHON PRESSURE VACUUM BREAKER

OPTIONAL
WYE STRAINER

POTABLE
SUPPLY

DOUBLE CHECK VALVE ASSEMBLY
TtEST PORTS *

TO NON HEALTH HAZARD-BACKPRESSURE
BACKFLOW APPLICATIONS

TEST PORTS

FLOOR OR WORKING SURFACE

NOTES:

1. Double check valve assemblies or reduced pressure backflow preventor assemblies are required for back
pressure applications.

2. Double check valve assemblies must be installed between 12" and 60" above the floor or other working
surface to provide sufficient access for periodic testing and maintenance.

3. Double check valve assemblies subject to back-siphonage require an intermediate vacuum breaker and a
relief vent.

4. Double check valve assemblies with an intermediate vacuum breaker and relief vent must not be located in
pit or other area subject to flooding. The relief vent will create a cross-connection if submerged.

Figure 10.5.5 - H

THE POTABLE WATER SUPPLY TO A NON-HEALTH HAZARD BACKFLOW APPLICATION

PROTECTED BY A DOUBLE CHECK VALVE ASSEMBLY

2J8

200t> National Standard f'lnmbmji Cotk-Uhniraied

TO A BACK-PRESSURE HEALTH HAZARD BACKFLOW APPLICATION SUCH AS
COOLING TOWER MAKEUP, BOiLER WATER MAKEUP, OR HYDRONIC PIPING
SYSTEM MAKEUP WHERE CHEMICAL TREATMENT IS PROVIDED AND THE
WATER IN THE PIPING SYSTEM IS NOT POTABLE.

OPTIONAL
STRAINER

REDUCED PRESSURE ZONE
BACKFLOW PREVENTOR ASSEMBLY

RESILIENT SEATED
SHUTOFF VALVES

See Note 2

AIR GAP OR
AIR GAP FITTING

FLOOR OR WORKING SURFACE

NOTES:

1. Double check valve assemblies are not permitted for health hazard applications.

2. Reduced pressure zone principle backflow prevention devices must be installed between 12" and
60" above the floor or other working surface to provide sufficient access for periodic testing and
maintenance.

3. RPZ devices must not be installed in pits or other area subject to flooding. The relief vent will create
a cross-connection if submerged.

4. If occasional spillage from the relief vent will cause damage or be a nuisance, the vent must be
equipped with an air gap fitting and indirectly drained to an acceptable point of disposal.

Figure 10.5.5 - 1

THE POTABLE WATER SUPPLY TO A HEALTH HAZARD BACKFLOW APPLICATION

PROTECTED BY A REDUCED PRESSURE BACKFLOW PREVENTER ASSEMBLY

10.5.6 Maintenance and Testing of Backflow Prevention Devices

a. Devices installed in a building potable water supply distribution system forprotection against
backflow shall be maintained in good working condition by the person orpersons responsible for the
maintenance of the system.

b. Devices that are designed to be field tested shall be tested prior to final inspection of the initial installa-
tion and once each year thereafter using field lest procedures conforming to ASSE 5010 Series Professional
Qualifications Standards or equivalent.

2006 National Standard Plumbing Code-IHttstnued

219

NOTE: Testable devices are those backflow prevention devices having test cocks and include, but are not
limited, to the following:

1 . Pressure vacuum breakers

2. Spill-resistant vacuum breakers

3. Double check valve assemblies

4. Double check detector assemblies

5. Reduced pressure backflow preventer assemblies

6. Reduced pressure detector assemblies

c. Where tests indicate that the device is not functioning properly, it shall be serviced or repaired in
accordance with the manufacturer's instructions and be retested.

d. Testing and repair of devices shall be performed by certified individuals approved by an agency
acceptable to the Authority Having Jurisdiction. Certification for testing shall be in accordance with ASSE
5000 or equivalent. Certification for repair shall be in accordance with ASSE 5030 or equivalent. Certification
shall include not less than 32 hours of combined classroom and practice training and successful completion of
a written and practical examination.

e. Copies of test reports for the initial installation shall be sent to the Authority Having Jurisdiction and the
water supplier. Copies of annual test reports shall be sent to the water supplier.

f. Where a continuous water supply is critical and cannot be interrupted for the periodic testing of a
backflow prevention device, multiple backflow prevention devices or other means of maintaining a continuous
supply shall be provided that does not create a potential cross connection.

1 0.5.7 Tanks and Vats— Below Rim Supply

a. Where a potable water outlet terminates below the rim of a tank or vat and the tank, or vat has an
overflow of a diameter not less than given in Table 1 0.8.3, the overflow pipe shall be provided with an air gap
as close to the tank as possible.

b. The potable water outlet to the tank or vat shall terminate a distance not less than 1-1/2 times the height
to which water can rise in the tank above the top of the overflow. This level shall be established at the
maximum flow rate of the supply to the tank or vat and with all outlets closed except the air-gapped overflow
outlet.

c. The distance from the outlet to the high water level shall be measured from the critical point of the
potable water supply outlet.

See Figure 10.5.7. Also Sections 10.8.3, 10.8.4, 10.8.5, and 10.8.6

220 200b Nulioiuii Standard Plumbing Code-lUustvuicJ

TANK WATER LEVEL
CONTROL VALVE

MAKE-UP
WATER SUPPLY

TANK OVERFLOW
See Note 2

REQUIRED AIR GAP
(See Note 5)

MAXIMUM OVERFLOW
WATER LEVEL
(See Note 4)

REQUIRED COVER

TANK VENT
See Note 1

INVERT OF OVERFLOW PIPE

POTABLE WATER

TANK DRAIN VALVE

POTABLE WATER TO
BOOSTER PUMP OR
GRAVITY SUPPLY TO
WATER DISTRIBUTION
SYSTEM

NOTES:

The covers of potable water tanks or vats must have screened vent pipes with internal areas not less

than that of the outlet pipe.

The size of the overflow pipe must comply with Table 10.8.3, based on the maximum makeup water

flow rate.

The air gap at the tank overflow discharge must be 2 X the inside diameter of the overflow pipe.

The maximum overflow water level must be established based on the size of the overflow pipe and

the maximum available makeup water flow. Calculated required static head or rise above the invert

of the overflow should be confirmed by operational tests under actual full flow conditions with the

tank outfet(s) closed.

The required air gap at the water inlet to the tank or vat must be at least 1-1/2 times the rise in

water level above the invert of the overflow outlet under maximum overflow conditions, measured from

the invert of the tank overflow.

Figure 10.5.7
A POTABLE WATER TANK OR VAT WITH ITS INLET BELOW THE OVERFLOW RIM

10.5.8 Connections to Carbonated Beverage Dispensers

The water supply to a carbonated beverage dispenser shall be protected against backflow with an integral
backflow preventer conforming to ASSE 1032 or an air gap. Carbonated beverage dispensers and carbon-
ated beverage dispensing systems without an integral backflow preventer conforming to ASSE 1032 or an air
gap shall have the water supply protected with a double check valve with atmospheric vent conforming to
ASSE 1032.

10.5.9 Protection from Fire Systems

a. Potable water supplies to water-based fire protection systems, including but not limited to standpipes
and automatic sprinkler systems, shall be protected from back-pressure and back-siphonage by one of the
following testable devices:

2006 National Standard Plumbing Cixle-tllitslrated

221

1. double check fire protection backflow protection assembly - ASSE 1015 (DCF)

2. double check detector fire protection backflow protection assembly - ASSE 1048 (DCDF)

3. reduced pressure principle fire protection backflow prevention assembly - ASSE 1013 (RPF)

4. reduced pressure detector fire protection backflow prevention assembly - ASSE 1047 (RPDF)
EXCEPTIONS

(1) ASSE 1024 dual check valves in residential sprinkler systems

(2) ASSE 1024 dual check valves in limited area sprinkler systems

(3) Where fire protection systems include a fire department connection, double check valve assembles shall
not be permitted.

(4) Where fire protection systems are filled with solutions that are considered to be health hazards as defined
in Section 1 .2, double check valve assemblies shall not be permitted.

b. Whenever a backflow protection device is installed in a potable water supply to a fire protection system, the
hydraulic design of the fire protection system shall account for the pressure drop through the backflow protection
device.

c. If backflow protection devices are retrofitted for an existing fire protection system, the hydraulics of the fire
protection system shall be checked to verify that there is sufficient water pressure available for satisfactory
operation of the fire protection system.

10.5.10 Protection from Lawn Sprinklers and Irrigation Systems

a. Potable water supplies to systems having no pumps or connections for pumping equipment, and no
chemical injection or provisions for chemical injection, shall be protected from backflow by one of the follow-
ing devices:

1 . Atmospheric vacuum breaker

2. Pressure vacuum breaker (PVB)

3. Spill-resistant vacuum breaker (SVB)

4. Reduced pressure backflow preventer assembly

b. Where sprinkler and irrigation systems have pumps, connections for pumping equipment, auxiliary air
tanks or are otherwise capable of creating back-pressure, the potable water supply shall be protected by the
following type of device if the backflow device is located upstream from the source of back -pressure.

J . Reduced pressure backflow 7 preventer assembly

c. Where systems have a backflow device installed downstream from a potable water supply pump or a
potable water supply pump connection, the device shall be one of the following:

1 . Atmospheric vacuum breaker

2. Pressure vacuum breaker (PVB)

3. Spill-resistant vacuum breaker (SVB)

4. Reduced pressure backflow preventer assembly

d. Where systems include a chemical injector or any provisions for chemical injection, the potable water
supply shall be protected by the following:

1 . Reduced pressure backflow preventer assembly

1 0.5. 1 1 Domestic Water Heat Exchangers

a. Heat exchangers used for heat transfer, heat recovery, or solar heating shall protect the potable water
system from being contaminated by the heat transfer medium, in accordance with either subparagraph b or c
below.

b. Single-wall heat exchangers shall be permitted if they satisfy all of the following requirements:

1 . The heat transfer medium is either potable water or contains only substances that
are recognized as safe by the U.S. Food and Drug Administration.

2. The pressure of the heat transfer medium is maintained less than the normal minimum
operating pressure of the potable water system.

2006 Nuiiumi! Standard Plumbing Code-Illustrated

•

EXCEPTION: Steam complying with subparagraph b.l.

3. The equipment is permanently labeled to indicate that only additives recognized as
safe by the FDA shall be used in the heat transfer medium,
c. Double-wall heat exchangers shall separate the potable water from the heat transfer medium by
providing a space between the two walls that is vented to the atmosphere.

10.5.12 Hose Connections

A pressure-type or atmospheric-type vacuum breaker or a permanently attached hose connection vacuum breaker
shall protect hose bibbs, sill-cocks, wall hydrants and other openings with a hose connection.
EXCEPTIONS:

( 1 ) Water heater and boiler drain valves that are provided with hose connection threads and that are intended
only for tank or vessel draining shall not be required to be equipped with a backflow preventer.

(2) This section shall not apply to water supply valves intended for connection to clothes washing machines
where backflow prevention is otherwise provided or is integral with the machine.

10.5.13 Protection for Special Equipment

The water supply for any equipment or device that creates a cross-connection with the potable water
supply shall be protected against backflow as required in Section 1 0.5. Such equipment and devices includes,
but is not limited to, chemical dispensers, portable cleaning equipment, sewer and drain cleaning equipment,
and dental pump equipment.

a. Chemical Dispensing Systems

Chemical dispensing systems with connections to the potable water distribution system shall protect the water
distribution system from backflow in accordance with ASSE 1055.

b. Portable Cleaning Equipment

Where the water distribution system connects to portable cleaning equipment, the water supply system shall
be protected against backflow in accordance with Section 1 0.5 , which allows for an atmospheric vacuum breaker,
pressure vacuum breaker, double check valve, or a reduced pressure principle assembly.

EXCEPTION: Atmospheric vacuum breakers shall not be used where there are shutoff valves or other shutoff
devices downstream or where they are subject to continuous flowing pressure for more than 1 2 hours at a time.

c. Dental Pump Equipment

Where the water distribution system connects to dental pumping equipment, the water supply system shall be
protected against backflow in accordance with Section 1 0.5, which allows for an atmospheric vacuum breaker,
pressure vacuum breaker, double check valve, or a reduced pressure principle assembly.

10.6 WATER SERVICE

1 0.6.1 Separation of Water Service and Building Sewer

The water service pipe and building drain or building sewer shall not have less than one foot horizontal
distance between the piping. See Figures 10.6.1 - A and - B

•

2006 National Standard PiuinhiitB Codti-lUusl rated

223

BUILDING DRAIN OR BUILDING SEWER

SUFFICIENT DEPTH
FOR FREEZE PROTECTION

NOTES:

1 . Improvements in the integrity of underground drainage system pipe joints has permitted the separa-
tion from potable water piping to be reduced to 1 2 inches.

Figure 10.6J - A

THE MINIMUM DISTANCE BETWEEN AN UNDERGROUND WATER SERVICE

AND A BUILDING DRAIN OR BUILDING SEWER

WATER SERVICE

BUILDING DRAIN
OR SEWER

WATER SERVICE OVER ( PREFERRED )

BUILDING DRAIN
OR SEWER

WATER SERVICE UNDER ( PERMITTED )

NOTES:

1 . The minimum clearance is 1 2 inches.

2. Where possible, the water service should cross over the building drain or building sewer.

3. If necessary , the water service can cross under the building drain or building sewer.

4. The 12" minimum separation prevents direct contact between the pipe lines, even with considerable
settlement.

Figure 10.6.1 - B

CROSSING A WATER SERVICE OVER (OR UNDER)

A BUILDING DRAIN OR BUILDING SEWER

224

1006 National Standard Plumbmx Cade-lllmlratt'd

•

10.6.2 Water Service Near Sources of Pollution

Potable water service piping shall not be located in, under, or above cesspools, septic tanks, septic tank
drainage fields, or drainage pits. A separation often feet shall be maintained from such systems. When a
water line parallels or crosses over or under a sewer, a minimum clearance of 12 inches in all directions shall
be maintained. See Figure 10.6.2

CESSPOOL, SEPTIC TANK,
SEPTIC TANK DRAINAGE FIELD,
AND DRAINAGE PIT

MINIMUM
CLEARANCE

10 FEET
MINIMUM

o^~

POTABLE WATER SERVICE PIPING

Figure 10.6.2

MINIMUM CLEARANCE BETWEEN A WATER SERVICE PIPE

AND SOURCES OF CONTAMINATION

10.63 Stop-and-Waste Valves Prohibited

Combination stop-and- waste valves or cocks shall not be installed underground in water service piping.

Comment: Open waste outlets on underground water service shutoff valves would permit ground water
to contaminate the potable water supply.

10.6.4 Water Service Pipe Sleeves

Pipe sleeves shall be provided where water service pipes penetrate foundation walls or floor slabs to protect
against corrosion of the pipe and allow clearance for expansion, contraction and settlement. The sleeve shall
form a watertight bond with the wall or floor slab. The annular space between the pipe and the sleeve shall
be resiliency sealed watertight. Where water service piping is plastic, the wall sleeve shall be not less than
five feel long extended outside beyond the wall. See Figure 10.6.4

•

2006 Miiivitaf Standard Plumbing Code-Hlttstraied

225

FLOOR SLAB -. S EE NOTE 2

PLASTIC WATER
SERViCE PIPE

5 FEET MINIMUM

FLOOR SLAB

WATER SERVICE PIPE SLEEVE
SEE NOTE 1

METALLIC WATER SERVICE PIPE

SEE NOTE 2

- SEE NOTE 2

•

NOTES

1. The pipe sleeve must be sealed watertight to the wall or floor slab.

2. A 1/2" minimum annular space around the water pipe, between the pipe and the sleeve, is required
and must be sealed watertight.

3. Sleeves for plastic water service pipe must extend outside beyond foundation walls to undisturbed
earth and be at least 5 feet long.

Figure 10.6.4
WATER SERVICE PIPE SLEEVES FOR METALLIC AND PLASTIC PIPING

10.6.5 Water Service Sizing

The water service pipe shall be of sufficient size to furnish water to the building in the quantities and at the
pressures required elsewhere in this Code. The pipe size shall not be less than 3/4 inch nominal.

10.7 WATER PUMPING AND STORAGE EQUIPMENT

1 0.7. 1 Pumps and Other Appliances

Water pumps, filters, softeners, tanks and other appliances and devices used to handle or treat potable water
shall be protected against contamination as per Section 10.5.

226

2006 National SlatuSard Plumbing Code-llhtxwatetl

•

10.7.2 Prohibited Location of Potable Supply Tanks

Potable water gravity tanks or manholes of potable water pressure tanks shall not be located directly under
any soil or waste piping.

10.8 WATER PRESSURE BOOSTER SYSTEMS

10.8.1 Water Pressure Booster Systems Required

a. When the water pressure in the public water main or individual water supply system is insufficient to
supply the potable peak demand flow to plumbing fixtures and other water needs freely and continuously with
the minimum pressure and quantities specified in Section 1 0. 1 4.3, or elsewhere in this Code, and in accor-
dance with good practice, the rate of supply shall be supplemented by one of the following methods:

1 . An elevated water tank.

2. A hydro-pneumatic pressure booster system.

3. A water pressure booster pump.

10.8.2 Reserved

1 0.8.3 Overflows for Water Supply Tanks

Gravity or suction water supply tanks shall be provided with an overflow having a diameter not less than that
shown in Table 10.8.3. The overflow outlet shall discharge above and within not less than 6 inches of a roof
or roof drain, floor or floor drain, or over an open water-supplied fixture. The overflow outlet shall be covered
by a corrosion-resistant screen of not less than 1 6 x 20 mesh to the inch and by 1/4 inch hardware cloth, or it
shall terminate in a horizontally installed 45° angle-seat check valve. Drainage from overflow pipes shall be
directed so as not to freeze on roof walkways. See Figure 10.5.7

Table 10.8.3
SIZES 1 OF OVERFLOW PIPES FOR WATER SUPPLY TANKS

Maximum Capacity Diameter of Maximum Capacity Diameter

of Water Supply Line Overflow Pipe of Water Supply Line Overflow Pipe

to Tank (Inches ID) to Tank (Inches ID)

0-13gpm 1-1/2 356-640 gpm 5

1 4-55 gpin 2 64 1-1040 gpm 6

56- 1 00 gpm 2-1/2 over 1040 gpm 8

I01-I65gpm 3

166-355 gpm 4

1 Computed by the method of NBS Mono. 31, for vertical pipes flowing not greater than 1/2 full at terminal velocity. ( 1/3 full for 1-1/2 in.
pipe).

10.8.4 Covers

All water supply tanks shall be covered to keep out unauthorized persons, dirt, and vermin. The covers of
gravity tanks shall be vented with a return bend vent pipe having an area not less than the area of the down
feed riser pipe and the vent shall be screened with corrosion resistant screen having not Jess than 14 and not
more than 20 openings per linear inch. See Figure 10.5.7

1 0.8.5 Potable Water Inlet Control and Location

Potable water inlets to gravity tanks shall be controlled by a ball cock or other automatic supply valve so
installed as to prevent the tank from overflowing. The inlet shall be terminated so as to provide an accepted
air gap but in no case less than 4 inches above the overflow.. See Figure 10.5.7

2006 National Standard Plumbing Code-Illustrated 227

10.8.6 Tank Drain Pipes

Each tank shall be provided at its lowest point with a valved pipe to permit emptying the tank. See Figure
10.5.7

1 0.8.7 Low Pressure Cut-Off Required on Booster Pumps

Booster pumps shall be protected by a low pressure cut-off switch to shut-off the pump(s) if the suction
pressure drops to an unsafe value.

1 0.8.8 Pressure Tanks — Vacuum Relief

All water pressure tanks shall be provided with a vacuum relief valve at the top of the tank that will operate
up to a maximum water pressure of 200 psi and to maximum water temperatures of 200°F. The minimum size
of such vacuum relief valves shall be 1/2 inch.

10.8.9 Pressure Tanks — Pressure Relief

All water pressure tanks shall be provided with approved pressure relief valves set at a pressure not in excess
of the tank working pressure.

10.9 FLUSHING AND DISINFECTING POTABLE WATER SYSTEMS

10.9.1 Flushing

The water service piping and distribution piping to all fixtures and outlets shall be flushed until the water runs
clear and free of debris or particles. Faucet aerators or screens shall be removed during flushing operations.

10.9.2 Disinfecting

a. Where required by the Authority Having Jurisdiction, the water service piping and the hot and cold water
distribution piping in new or renovated potable water systems shall be disinfected after flushing and prior to
use. The procedure used shall be as follows or an approved equivalent:

1 . All water outlets shall be posted to warn against use during disinfecting operations.

2. Disinfecting shall be performed by persons experienced in such work.

3. The water supply to the piping system or parts thereof being disinfected shall be valved-off from the
normal water source to prevent the introduction of disinfecting agents into a public water supply or portions of
a system that are not being disinfected.

4. The piping shall be disinfected with a water-chlorine solution. During the injection of the disinfecting
agent into the piping, each outlet shall be fully opened several times until a concentration of not less than 50
parts per million chlorine is present at every outlet. The solution shall be allowed to stand in the piping for at
least 24 hours.

5. An acceptable alternate to the 50 ppm/24-hour procedure described in Section 10.9.2.d shall be to
maintain a level of not less than 200 parts per million chlorine for not less than three hours. If this alternate
procedure is used, the heavily concentrated chlorine shall not be allowed to stand in the piping system for
more than 6 hours. Also, special procedures shall be used to dispose of the heavily concentrated chlorine in an
environmentally acceptable and approved manner.

6. At the end of the required retention time, the residual level of chlorine at every outlet shall be not less
than five parts per million. If the residual is less than five parts per million, the disinfecting procedure shall be
repeated until the required minimum chlorine residual is obtained at every outlet.

7. After the required residual chlorine level is obtained at every outlet, the system shall be flushed to
remove the disinfecting agent. Flushing shall continue until the chlorine level at every outlet is reduced to that
of the incoming water supply.

228 2006 National Standard Plumbing Codc-lUusiraied

8. Any faucet aerators or screens that were removed under Section 10.9.1 shall be replaced.

9. A certification of performance and laboratory test report showing the absence of coliform organisms
shall be submitted to the Authority Having Jurisdiction upon satisfactory completion of the disinfecting opera-
tions.

10.10 WATER SUPPLY SYSTEM MATERIALS

See Section 3.4.3.

10.11 ALLOWANCE FOR CHARACTER OF SOIL AND WATER

When selecting the material and size for water service supply pipe, tube, or fittings, due consideration shall be
given to the action of the water on the interior of the pipe and of the soil, fill or other material on the exterior of the
pipe. (Appendix B gives recommendations concerning allowances to be made in sizing water piping because of the
properties of the water.)

Comment: The chemical composition of the service water should be considered when selecting the water
service pipe material. Refer to Appendix Section E. 2.3. The aggressive nature of the soil or fill material
around the water service pipe should be evaluated when considering if additional corrosion protection is
need for the exterior surfaces of the pipe.

•

10.12 WATER SUPPLY CONTROL VALVES

10.12.1 CurbValve

On the water service from the street main to the building, an approved gate valve or ground key stopcock or
ball valve shall be installed near the curb line between the property line and the curb. This valve or stopcock
shall be provided with an approved curb valve box. See Figure 1.2.82

10.12.2 Building Valve

The building water service shall be provided with a readily accessible gate valve with bleed or other full -way
valve with bleed located inside the building near the point where the water service enters. When the building
water service enters a crawl space, the building valve shall be readily accessible. Where there are two or
more water services serving one building, a check valve shall be installed on each service in addition to the
above valves. See Figure 1.2.82

10.12.3 Water Supply Tank Valve

A shutoff valve shall be provided at the outlet of any tank serving as a water supply source, either by gravity
or pressure. See Figure 10.5.7

10.12.4 Valves in Dwelling Units

a. Except as defined in 10.12.4.b, c and d, individual fixture shutoff or stop valves shall be provided for water
closets, lavatories, kitchen sinks, laundry trays, bar sinks, bidets, clothes washing machines, sill cocks, wall
hydrants, appliances and equipment connected to the water supply system. Valves for fixtures, appliances and
equipment shall be accessible without having to move the appliance or equipment.

EXCEPTION. Valves for ice makers

b. Shutoff valves shall be provided for each powder room or bathroom group unless all fixtures within the
room or group have individual fixture shutoff or stop valves.

c. In a single dwelling unit, two bathrooms or powder rooms installed back-to-back or one directly above the

2006 National Standard Plumbing Code-Illustrated 129

other may be considered as a single group and shall be permitted to have one set of shutoff valves. If two
such rooms are not piped as a single group, separate shutoff valves shall be provided for each room or group.

d. In multi-dwelling units, one or more shutoff valves shall be provided in each dwelling unit so that the water
supply to any plumbing fixture or group of fixtures in that dwelling unit can be shut off without stopping the
water supply to fixtures in other dwelling units. These valves shall be accessible in the dwelling unit that they
control.

e. Self-piercing and needle-type saddle valves shall be prohibited.
See Figures 10J2.4-A and-B

REFRIGERATOR
WITH ICE MAKER

•

StLL COCK OR
WALL HYDRANT

WATER SERVICE

NOTES

1 . The building shutoff valve must be a full-way type with a bleed to drain the piping within the building.

2. The water heater shutoff valve must not be a globe valve.

3. Additional shutoff valves can be provided to isolate the water heater and branches of the water
distribution piping.

4. Shutoff valves for powder rooms and bathroom groups are not required if all fixtures within the group
have individual shutoff valves. One set of shutoff valves can serve two bathroom groups if they are
piped as one group of fixtures without separate branch pipes for each group.

5. Water closets and lavatories usually have individual supply stop valves where the fixture supply tube
connects to the fixture branch supply pipe.

6. Where manifold-type parallel water distribution systems are used, the individual fixture shutoff valves
are located on the manifold.

Figure 10.12.4 - A
REQUIRED WATER SHUTOFF VALVES IN SINGLE DWELLING UNITS

230

2006 Nuiioiiiil Standard Plumbing Coder it hu! rated

KITCHEN SINK

LAV

TUB

INDIVIDUAL
DWELLING UNIT

BATHROOM
GROUP

KITCHEN SINK

LAV

TUB

INDIVIDUAL
DWELLING UNIT

WC - WATER CLOSET
LAV - LAVATORY
® - REQUIRED SHUTOFF VALVE

BATHROOM
GROUP

RISER VALVES

NOTES

1. Risershutoff valves are required where risers serve dwelling units on two or more floors.

2. Shutting off a fixture in one dwelling unit must not stop the water supply to a fixture in another
dwelling unit

3. Main shutoff valves are not mandatory for each dwelling unit if all fixtures within the unit have a
means of shutoff.

4. Shutoff valves for powder rooms and bathroom groups are not mandatory if all fixtures within the
group have individual shutoff valves. One set of shutoff valves can serve two bathroom groups within
the same dwelling unit if they are piped as one group of fixtures without separate branch pipes for
each group.

5. Water closets and lavatories usually have individual supply stop valves where the fixture supply tube
connects to the fixture branch supply pipe.

6. All shutoff valves for the fixtures in each dwelling unit must be accessible within the dwelling unit
thatthey serve.

Figure 10.12.4 - B
REQUIRED WATER SHUTOFF VALVES IN MULTI-DWELLING UNITS

10.12.5 Riser Valves

Shutoff valves(s) shall be provided for isolating each water supply riser serving fixtures on two or more

floors.

EXCEPTION: Risers within individual dwelling units. See Figure 1.2.49

2006 National Standard Plumbing Code-llhtsiroied

231

10.12.6 Individual Fixture Valves

In a building used or intended to be used for other than dwelling purposes, the water distribution pipe to each
fixture or other piece of equipment shall be provided with a valve or fixture stop to shut off the water to the
fixture or to the room in which it is located. These valves shall be accessible. Sill cocks and wall hydrants
shall be separately controlled by a valve inside the building.

Comment: In buildings or portions thereof that are used for other than dwelling purposes, each fixture
or equipment connection must have an individual shutoff means. Shutoff valves in such systems cannot
shutoffa group of fixtures that do not have individual shutoff means. The guest rooms in hotels and
motels are considered to be dwelling units.

10.12.7 Water Heating Equipment Valve

A shutoff valve shall be provided in the cold water supply to each water heater. If a shutoff valve is also
provided in the hot water supply from the heater, it shall not isolate any safety devices from the heater or
storage tank. Shutoff valves for water heaters shall be the gate, ball, plug, or butterfly type. See Figure
10.12.7

COLD

OPTIONAL HOT WATER
SHUTOFF VALVE

DRAIN VALVE

COLD WATER
SHUTOFF VALVE

RELIEF VALVE

RELIEF VALVE DISCHARGE PIPE

TO APPROVED POINT OF DISCHARGE

DIP TUBE

1 . The cold water shutoff valve permits the water heater to be serviced or replaced, but requires that
the hot water distribution piping be drained.

2. The optional hot water shutoff valve permits the water heater to be serviced or replaced without
draining the hot water distribution piping.

3. The water heater relief valve must not be isolated from the water heater tank by any shutoff valves.

4. Water heater shutoff valves must be the full-flow type. Globe valves are not permitted.

Figure 10.12.7
WATER HEATER SHUTOFF VALVE(S)

232

10Q(> National Standard Plumbing Code-lilusireited

10.12.8 Meter Valve

A gate valve or other full-way valve shall be installed in the line on the discharge side of each water meter.
The valve shall not be less in size than the building water service pipe.
See Figures 10.12.8-A and-B

METER FRAME & COVER

SIDEWALK

ROADWAY

CORPORATION COCK

WATER SERVICE
TO BUILDING

NOTES:

1. The stop valve on the inlet side of the water meter is normally provided by the water service utility. It
can be the curb valve required by Section 10.12.1.

2. The distinction between small and large water services is dictated by the Authority Having Jurisdic-
tion. For small water services, the shutoff valve on the outlet side of the water meter can be the
building valve required by Section 1 0. 12.2. See Figure 1 0. 1 2.8 - B for larger water services.

3. Adapter fittings are required where the pipe material for the water service to the building is different
from the pipe material provided by the water utility.

Figure 10.12.8 - A
METER SHUTOFF VALVES IN A SMALL WATER SERVICE

2006 National Standard Hwiibwg Codi'-liltt.Uratcd

233

METER VAULT

WATER SUPPLY FROM
PUBLIC WATER MAIN

NOTES:

1. The shutoff valve on the inlet side of the water meter is normally provided by the water utility.

2. The bypass valve is optional. It can be used to provide continuous water service while the meter is
being repaired or replaced.

3. The bypass valve and shutoff valve on the meter outlet permit the meter to be repaired or replaced
without interrupting the water service to the facility.

Figure 10.12.8 - B
METER SHUTOFF VALVES IN A LARGE WATER SERVICE

10.12.9 Valve Accessibility

Water supply control valves shall be placed so as to be accessible for service and maintenance.

Comment: Access to water supply shutoff valves can require the use of tools to remove access panels or
doors.

10.13 FLEXIBLE WATER CONNECTORS

Flexible water connectors exposed to continuous pressure shall conform to ASME Al 12.18.6. Access shall be
provided to aJl flexible water connectors.

10.14 MINIMUM REQUIREMENTS FOR WATER DISTRIBUTION

SYSTEMS

10.14.1 Maximum Velocity (See Appendix B.6)

Water distribution piping within buildings shall be sized for a maximum velocity of 8 feet per second at the
design flow rate unless the pipe manufacturer's sizing recommendations call for the maximum velocity to be
less than 8 feet per second.

234

2006 NattMuil Siatuiant Plumbing Code-Iltusuaieil

10.14.2 Size of Individual Fixture Supply Branches

a. Individual fixture supply branch pipe sizes shall be based on the minimum available flowing water
pressure at the point of connection to the water distribution system, any elevation difference between that
connection and the fixture, and the allowable pressure loss in the fixture supply branch. The minimum fixture
supply branch pipe sizes shall be as indicated in Table 10.14.2A. For design purposes, the required pressure at
each fixture inlet shall be 1 5 psig minimum with flow for all fixtures, except 20 psig flowing for flushometer
valves on siphon jet water closets and 25 psig flowing for flushometer valves on blowout water closets and
blowout urinals. Flushometer tank (pressure assisted) water closets require a minimum of 25 psig static
pressure. The following water flow rates shall be used for the purpose of sizing individual fixture supply
branch pipes:

5.0 gpm for hose bibbs and wall hydrants;

4.0 gpm for bath faucets and clothes washers;

0.75 gpm for drinking fountains and water coolers;

2.5 gpm for sink faucets;

2.5 gpm for showers;

1 .5 gpm for lavatory faucets;

3.0 gpm for water closets other than the flushometer valve type;

1 2.0 gpm for flushometer valve urinals;

30.0 gpm for flushometer valve water closets

b. Fixture supply branches shall extend from the distribution system to within 30 inches of the point of
connection to the fixture or device served and be within the same area and physical space as the point of
connection to the fixture or device. Fixture supply tubes and flexible water connectors shall be not less than
the size recommended by the manufacturer of the fixture, faucet, appliance or device served.

•

10.14.3 Sizing Water Distribution Piping

a. The supply demand in gallons per minute in the building hot and cold water distribution system shall be
determined on the basis of the load in terms of water supply fixture units (WSFU) as shown in Table

1 0. 1 4.2A and the relationship between the load in WSFU and the supply demand in gallons per minute (gpm)
as shown in Table 10. 14.2B. For fixtures having both hot water and cold water connections, the separate hot
water and cold water loads shall be taken as 75% of the listed fixture unit value.

b. Main risers and branches of the water distribution system shall be sized based on the minimum available
water pressure at the source, any elevation differences between the source and the fixtures, pressure losses
in the distribution system, and the pressure (with flow) required at each connection of the fixture supply
branches.

10. J 4.4 Inadequate Water Pressure

Whenever water pressure from the street main or other sources of supply is insufficient to provide flow
pressures at fixture outlets as required under Section 10.14.3, a booster pump and pressure tank or other
approved means shall be installed on the building water supply system.

•

2006 National Standard Plumbing Code-Illustrated

235

Table 10.14.2A

WATER SUPPLY FIXTURE UNITS (WSFU) AND MINIMUM FIXTURE BRANCH

PIPE SIZES

HEAVY-USE ASSEMBLY

TYPE OF FIXTURES OTHER THAN DWELLING UNITS

SERVING 3 OR MORE DWELLING UNITS

INDIVIDUAL DWELLING UNITS

MINIMUM BRAN* II PIPE SIZE

R\ 1 11 ROOM CROIPS IUVING !A GPF WATLR
CI t ><> I v OniKR III VN fflK FU S'HOMI- 1 VR
\ \1VI- HPF

A l„V *

^ ,

Mill ■ l'i I'- v 1 - "' iim

3 i

i. T

1 Bathroom Group

- II

■

I 'A Bathrooms

n(i

2 Bathrooms

" 11

2 J A Bathrooms

•^ 1

3 Bathrooms

Each Additional 'A Baih

ii ;

Each Additional Bathroom Group

. &ATHROOM CROUPS HAVING 3.5 GPF
^ .GRAVltY-T^iK WATER CLOSETS , •"'

-J 4 "* "

* 1

Hall-b.'ith or Powdci Room

: ii

< '1

1 Bathroom Group

! 'A Bathrooms

<■■>

2 Bathrooms

ii>u

2 'A Bathrooms

il ii

3 Bathrooms

i:n

Each Additional 'A Bath

Each Additional Bathroom Group

; (i

BATH GROUP (1.6 GPP FJushometer Valve)

: £0

•o

BATH GROUP (3.5 GPF Flushometer Valve)

:,*(>

h-i

KITCHEN GROUP (Sink and Dishwasher)

I '

LAUNDRY GROUP (Sink and Clolhes Washer)

. ii

236

2006 NuiiQini' Standard Plumbing Code-ftlusiratod

Table 10. 14.2 A (Continued)

WATER SUPPLY FIXTURE UNITS (WSFU) AND MINIMUM FIXTURE BRANCH

PIPE SIZES

HEAVY-USE ASSEMB

TYPE OF FIXTURES OTHER THAN DWELLING UNITS

SERVING 3 OR MORE DWELLING UNITS

INDIVIDUAL DWELLING UNITS

MINIMUM BRANCH PIPL SIZE

ijpmiynjiiAiLFcrruRf^ i y YKJ * / — ,, v

mm-

§lgl§"£

lt%lll

Mite

Bathtub oi Combination Bith Shower

*S« i

Bidet

V:"

1.0

■<l, /' "'■

* ^ jf

Clothes Washer. Domestic

•/;■■

4.0

Dishwasher, Domestic

V,"

1.5

' ' 4

Drinking Fountain or Watercoolcr

Vs"

*"??* *

C-V

Hose Bibb

V 2 "

2.5

v<«

Hose Bibb. Each Additional

1.0

. '. **%

Kitchen Sink, Domestic

V,"

1.5

1.0

1.5

Laundry Sink

V 2 "

2.0

1.0

2.0

Lavatory

1.0

0.5

1.0

Service Sink or Mop Basin

'/,"

t 4 -

3.0

Shower

Vj"

2.0

Shower. Continuous Use

V»"

. '

* J r

5.0

Urinal. 1.0 GPF

3/ i.
'it

J *-

4.0

5.0

Urinal, Greater Than 1.0 GPF

3/ ■>
'J

5.0

6.0

Water Closet, 1 6 GPF Gravity Tank

''■."

2 ^

2 s

2.5

4.0

Water Closet, L6 GPF Flushometer Tank

1 ,' ■>

2 5

2.5

3.5

Water Closet, 1.6 GPF Flushometer Valve

5.0

Waier Closet, 3 5 GPF Gravity Tank

'•■'■>"

3.0

5.5

7.0

Water Closet, 5.5 GPF Flushometer Valve

7.0

8.0

10.0

Whirlpool Bath or Combination Bath/Shower

4.0

* - , -

NOTES:

I . A Bathroom Group, for the purposes of this Table, consists of not more than one water closet, up to two lavatories, and either one baihrub.
one bath/shower combinaJion. or one shower stall. Other fixtures within the bathing facility shall be counted separately to determine the total
water supply fixture unit load.

2. A Half-Bath or Powder Room, for the purposes of this Table, consists of one water closet and one lavatory.

3. For unlisted fixtures, refer to a listed fixture having a similar flow and frequency of use.

4. The listed fixture unit values for Bathroom Groups and Individual Fixtures represent their load on the cold waler service. The separate cold
water and hot water fixture unit values for fixtures having both cold and hot water connections shaii each be taken as 3/4 of the listed total value
for the individual fixture..

5. Wlien WSFU values are added to determine the demand on the water distribution system or portions thereof round ihe sum to the nearest
whole number before referring to fable 10.14 2B for the corresponding gallons per minute (gpnij flow. WSFU values of 0,5 or more should be
rounded up to the next higher whole number (9.5 = W WSFUj. Values of 0.4 or less should be rounded down to the next lower whole number (9.4
- 9 WSFU).

6. The listed minimum supply branch pipe sizes for individual fixtures are the nominal (ID) pipe size in inches.

7. "Other Than Dwelling Units" applies to business, commercial, industrial, and assembly occupancies other than Ihose defined under "Heavy-
Use Assembly." Included are the public and common areas in hotels, motels, and multi-dwelling buildings.

8. "Heavy-Use Assembly" applies to toilet facilities in occupancies that place heavy, but intermittent, time-based demands on the water
supply system, such as' schools, auditoriums, stadiums, race courses, transportation terminals, theaters, and similar occupancies where queuing is
likely to occur during periods of peak use.

9. For fixtures or supply connections likely lo impose continuous flow demands, determine their required flow in gallons per minute (gpmj and
add it separately to the demand (in gpm) lor the distribution system or portion thereof.

2006 National Standard Plunibinp Ct>dt>-l(ias\ruied

237

Table 10.14.2B

TABLE FOR CONVERTING DEMAND IN WSFU TO GPM 1

GPM

WSFU

Flush Tanks 2

Flush Valves 3

WSFU Flush Tanks 2

Flush Valves 3

120 49

140 53

4.5

160 57

180 61

200 65

225 70

7.5

250 75

100

300 85

110

8.5

400 105

125

500 125

140

29.5

750 170

175

10.5

1000 210

210

1250 240

240

1500 270

270

12.5

1750 300

300

33.5

2000 325

325

13.5

2500 380

380

3000 435

435

4000 525

525

5000 600

600

6000 650

650

7000 700

700

8000 730

730

9000 760

760

100

10,000 790

790

NOTES:

i . This table converts water supply demands in water supply fixture units (WSFU) to required water flow in gallons per minute (GPM)

for the purpose of pipe sizing.

2. This column applies to portions of piping systems where the water closets are the flush tank type (gravity or pressure) or there arc no
water closets, and to hot water piping.

3. This column applies to portions of piping systems where the water closets are the flush valve type.

10.14.5 Variable Street Pressures

Where street water main pressures fluctuate, the building water distribution system shall be designed for the
minimum pressure available.

238

1.00b National Standard Plumbing Code-lllusirattd

•

10.14.6 Excessive Pressures

a. Approved pressure reducing valves complying with ASSE 1003 shall be provided if required to limit the
water supply pressure at any fixture appliance, appurtenance, or outlet to not more than 80 psi under no-flow
conditions.

b. The requirement of Section 1 0. 1 4, 6. a above shall not prohibit supply pressures higher than 80 psi to
water pressure booster systems under Section 1 0. 14.4 or in high pressure distribution systems, provided that
the pressure at the fixtures served is subsequently reduced to 80 psi maximum. Where operating water
pressures exceed 80 psi, the working pressure rating of materials and equipment shall be suitable for the
maximum pressure that may be encountered, including temporary increases or surges.

c. Where pressure reducing valves are installed and the downstream piping is not rated for the maximum
upstream pressure, a pressure relief valve shall be installed downstream from the pressure reducing valve.
The relief valve shall be set not higher than the working pressure rating of the downstream piping and sized
for not less than the flow capacity of the pressure reducing valve. Relief valves shall discharge in accordance
with Sections 1 0. 1 6.6a, b. c, and d.
See Figures 10.14.6-A and-B

SUPPLY PRESSURE TO FIXTURES
REDUCED TO 80 P.S.I. MAX.

BUILDING VALVE
(Section 10.12.2)

PRESSURE RELIEF VALVE
(IF REQUIRED)

PRESSURE

REDUCING VALVE TO APPROVED

(Section 1 0. 14.6) POINT OF

DISCHARGE

SUPPLY PRESSURE
GREATER THAN 80 psi

NOTES:

1. Example: A pressure booster pump is required lo deliver domestic water lo the 18th floor.

2. The 1s1, 2nd, and 3rd Floors are supplied with street pressure and a separate hot water heater.

3- Without pressure reducing valves, the water supply pressure on the 4th through 13th Floors would exceed 80 psig.

4. Generally, up to five floors can be zoned with one set of pressure reducing valves withoul having excessive pressure
differences between the top and bottom floors of the zone.

5. The pressure in the hot water recirculation line is essentially the same as in the adjacent hot water supply riser.

6. The diagram shows only the hot water riser recirculated. If hot water must be circulated from the individual floors, pressure
booster pumps would be required to pump the recirculated water from each reduced pressure zone back into the higher-pressure
return riser (the downcomer).

Figure 10.14.6 - A

INSTALLATION OF A WATER PRESSURE REDUCING VALVE

WHERE THE WATER SUPPLY PRESSURE EXCEEDS 80 PSIG

2006 National Standard Plumbing Code-Illustrated

239

HOT WATER
RECIRCULATION

INSERT B

DOMESTIC WATER
BOOSTER PUMP"

WATER
SUPPLY "

/ PRV \

—^-fXI — fc$p-HW-f-

Y prv y
INSERT A

See Note 6

^, B J

l A >

18 TH FLOOR
17 TH FLOOR
16 TH FLOOR
15 TH FLOOR
14 TH FLOOR

13THFLOOR
12THFLOOR
11 TH FLOOR
10 TH FLOOR
9 TH FLOOR

HOT WATER
CIRCULATOR

NOTES:

1. Example: A pressure booster pump is required to deliver domestic water to the 18th floor.

2. The 1st, 2nd, and 3rd Floors are supplied with street pressure and a separate hot water heater.

3. Without pressure reducing valves, the water supply pressure on the 4th through 13th Floors would
exceed 80 psig.

4. Generally, up to five floors can be zoned with one set of pressure reducing valves without having
excessive pressure differences between the top and bottom floors of the zone.

5. The pressure in the hot water recirculation line is essentially the same as in the adjacent hot water
supply riser.

6. The diagram shows only the hot water riser recirculated. If hot water must be circulated from the
individual floors, pressure booster pumps would be required to pump the recirculated water from
each reduced pressure zone back into the higher-pressure return riser (the downcomer).

Figure 10,14.6 - B

ONE POSSIBLE ARRANGEMENT OF PRESSURE REDUCING VALVES

IN A HIGH-RISE BUILDING

10.14.7 Water Hammer

a. Approved water hammer arresters, complying with ANS1/ASSE J 010, shall be installed on water
distribution piping in which quick closing valves are installed.

EXCEPTION: Single lever faucets, domestic clothes washers, and domestic dishwashers.

b. Water hammer arresters shall be placed as close as possible to the quick acting valve, at the end of long
piping runs, or near batteries of fixtures,

c. Arresters shall be accessible for replacement. See Figure 10.14.7

240

2006 National Standard Plumbing Code-IHusimteti

f=)

PRESSURIZED
AIR / GAS —
CUSHION

CONNECTION TO
WATER PIPING

DIAPHRAGM
TYPE

PISTON
TYPE

■ "O" - RING SEAL
PISTON

NOTES:

1. Water hammer arrestors should be sized and installed according to the manufacturer's instructions.

2. PDI Standard WH201 establishes PDI Sizes "A" through "F" with recommendations on the number
of fixture units served by each size. Most manufacturers rank their products to the PDI Sizes.

3. Water hammer arrestors can be installed vertically or horizontally. They should be installed on the
run of a tee fitting so that the unobstructed shock path is directly into the water hammer arrestor.
See Figure 1.2.3.

4. The number of elbows upstream from a water hammer arrestor should be minimized because they
create points of shock before the arrestor.

5. Water hammer arrestors must be accessible and have a means of shutoff to permit replacement if
necessary. The means of shutoff can be a shutoff valve for a group of fixtures.

Figure 10.14.7
WATER HAMMER ARRESTORS

10.15 HOT WATER

10.15.1 Hot Water Supply System

In residences and buildings intended for human occupancy, hot water shall be supplied to all plumbing fixtures
and equipment used for bathing, washing, culinary purposes, cleansing, laundry or building maintenance. With
the approval of the Authority Having Jurisdiction, tempered water supply systems may be installed in lieu of
hot and cold water systems in buildings other than dwelling units.

1 0.1 5.2 Temperature Maintenance Where Required

a. Heated water distribution systems in buildings where developed length of heated water piping from the
source of the heated water to the farthest fixture exceeds 1 00 feet shall maintain heated water temperature in
all supply piping to within 25 feet of any heated water outlet.

b. An approved electric heat tracing system shall be permitted to be used to satisfy the requirements of
Section 10.15.2a. See Figure 10.15.2

'2006 National Standard Plumbing CiHfe-Illusi rased

241

t t

25 FEET MAXIMUM

DISTANCE TO FARTHEST HOT WATER OUTLET EXCEEDS 100 FEET

COLD-

CHECK
VALVE .
(NOTE 2)

HOT-

EXP.

TANK

t/Hcm-i

<^— ■

BALANCING COCKS (NOTE 3)
RECIRCULATED LINE

HOT
WATER
SOURCE

L -AQUASTAT(NOTE 1)
CIRCULATOR

XZJ

TEMPERATURE MAINTAINED TO WITHIN
25 FEET OF ALL HOT WATER OUTLETS - 1

NOTES:

1. The aquastat or time/temperature controller starts the circulator when the recirculated line cools.
The circulator stops when the line temperature rises.

2. The check valve in the cold water supply to the hot water source keeps recirculated hot water from
flowing into the cold water main due to pressure fluctuations in the distribution system.

3. If the recirculation piping has more than one branch, balancing cocks in each branch permit the
flows to be adjusted.

4. A means of measuring the return temperature should be provided.

Figure 10.15.2
HOT WATER TEMPERATURE MA1NTAINENCE BY RECIRCULATION

10.15.3 Minimum Requirements forHot Water Storage Tanks

a. Hot water storage tanks shall be adequate in size, when combined with the B.T.U.H. input of the water
heating equipment to provide the rise in temperature necessary.

b. Water heaters and storage tanks shall be sized to provide sufficient hot water to provide both daily
requirements and hourly peak loads of the occupants of the building.

c. Storage tanks shall be protected against excessive temperatures and pressure conditions as specified in
this Code. (See Sections 3.3.8 and 3.3.10)

10.15.4 Drainage of Hot Water Storage Tanks

Hot water storage tanks shall be equipped with a valve capable of draining the tank completely. See Figure
10.12.7

242

2006 National Standard Plumbing Code-Hl usimted

10.15.5 Pressure Marking of Hot Water Storage Tanks

Hot water storage tanks shall be permanently marked in an accessible place with the maximum allowable
working pressure, in accordance with the applicable standard as listed in Table 3.1 .3.

10.1 5.6 Mixed Water Temperature Control

a. Showers and Bath/Shower Combinations: AH showers and bath/shower combinations shall be provided with
individual balanced pressure, thermostatic, or combination automatic compensating valves that comply with
ASSE 1016 or ASME Al 12.18.1/CSA B125.1. These valves shall include a means to limit the maximum
discharge temperature of the water and shall be installed and field-adjusted in accordance with the manufacturer's
instructions to a maximum of 1 20°F. No further mixing of water shall be permitted downstream of the automatic
compensating valve.

EXCEPTION: Where multiple showers are supplied by a one-pipe tempered water distribution system, the
tempered water distribution system shall be controlled by an automatic temperature control mixing valve
complying with ASSE 1 069. These valves shall include a means to limit the maximum discharge temperature of
the water and shall be installed and field-adjusted in accordance with the manufacturer's instructions to a
maximum of 1 20°F. No further mixing of water shall be permitted downstream of the automatic temperature
controlled mixing valve.

b. Bathtubs and Whirlpool Baths: The water discharged into bathtubs and whirlpool baths, with or without
deck-mounted hand sprays, shall be controlled to a maximum temperature of 1 20°F by a device complying
with CSAB125.3, ASSE 1070, ASME Bl 12.1 8. 1/CSAB125.1 or ASSE 1016.

c. Public-Use Hand Washing Facilities: Water discharged from public-use hand washing facilities shall be
limited to a maximum temperature of 1 1 0°F using a water temperature limiting device complying with ASSE
1070.

d. Commercial Hair/Shampoo Sink Sprays: The temperature of water discharged from commercial hair/
shampoo sink sprays shall be limited to a maximum of 1 1 0°F by a water temperature-limiting device comply-
ing with ASSE 1070, ASME Al 12.18.1/CSA B 125.1, or CSA B 1 25. 3.

e. Temperature Actuated Flow Reduction (TAFR) Devices: Where temperature actuated flow reduction
(TAFR) devices are installed to limit the maximum discharge temperature to 120°F for individual fixture
fittings, such devices shall comply with ASSE 1062. These devices alone shall not supersede the other
requirements of Section 10.15.6.

f. ln-Line Pressure Balancing Valves: Where in-line pressure balancing valves are installed to compensate
for water pressure fluctuations to stabilize the temperature discharges from their individual faucet or fixture
fitting, such devices shall comply with ASSE 1066. These devices shall be installed in an accessible location
and alone shall not supersede the other requirements of Section 1 0. 15.6

g. Temperature-Actuated Mixing Valves: Where temperature-actuated mixing valves are installed to
control the in-line hot water supply temperature in the water distribution system, they shall comply with
ASSE 1017. Such devices shall be installed at the hot water source and alone shall not supersede the other
requirements of Section 10.15.6 for mixed water temperature control.

h. The temperature control devices for water heaters and other hot water supply sources shall not be
permitted to be used to meet this Section's requirements for mixed water temperature control.

i. Alternative Methods: The use of a combination of water temperature control or limiting devices that
comply with the standards listed in Table 3.1.3 and satisfy the performance requirements of Section 10. 15.6
shall be subject to the approval of the Authority Having Jurisdiction.

10.15.7 Thermal Expansion Control

Where a back flow prevention device, check valve or water pressure regulator is installed serving water

heating equipment such that a closed system is created, a device for controlling thermal expansion shall be

installed.

EXCEPTION: Instantaneous water heaters.

2006 National Standard Plumbing Cade-Illustrated

243

10.15.8 Plastic Piping

a. Plastic piping used for hot water distribution shall conform to the requirements of Section 3.4 and Table
3.4. Piping shall be water pressure rated for not less than 1 00 psi at 1 80°F and 1 60 psi at 73°

NOTE: The working pressure rating for certain approved plastic piping materials varies depending on
material composition, pipe size, wall thickness and method of joining. See Table 3.4.3.

b. Plastic pipe or tube shall not be used downstream from instantaneous water heaters, immersion water heaters
or other heaters not having approved temperature safety devices.

c. Piping within six inches of flue or vent connectors shall be approved metallic pipe or tube.

d. The normal operating pressure in water distribution piping systems utilizing approved plastic pipe or tube for
hot water distribution shall be not more than 80 psi. Where necessary, one or more pressure reducing valves shall
be provided to regulate the hot and cold water supply pressure to not more than 80 psi.

e. The pressure in the hot water distribution piping shall be limited by a pressure relief valve set no higher than
listed in Table 1 0. 1 5 .8 for the particular plastic piping material. When the water heater is protected by a pressure
relief valve or combination pressure-temperature relief valve having a pressure setting higher than listed in Table
1 0. 1 5.8, a separate pressure relief valve shall be provided to protect the piping. The relief valve for the piping
shall comply with Section 10.16.2 except that it shall be set no higher than listed in Table 10.15.8. Thermal
expansion shall be controlled as required under Section 1 0. 1 5.7.

Table 10.15.8

MAXIMUM PRESSURE RELIEF VALVE SETTINGS

FOR PLASTIC HOT WATER DISTRIBUTION PIPING

HW DISTRIBUTION
PIPING MATERIAL

MAX. RELIEF
VALVE SETTING

CPVC (ASTM D2846)

lOOpsig

CPVC(ASTM F441)

lOOpsig

CPVC (ASTM F442)

100 psi g

PEX (ASTM F876)

1 00 psig

PEX (ASTM F877)

lOOpsig

PE-AL-PE (ASTM D 1282)

100 psig

PEX-AL-PEX (ASTM FI281)

125 psig

Composite High Temperature PE-AL-PE (ASTM D1335)

1 50 psig

Composite High Temperature PEX-AL-PE (ASTM D1335)

150 psig

10.15.9 Drip Pans

10.15.9.1 Where Required

Where water heaters or hot water storage tanks are installed in locations where leakage will cause
damage to the building structure, the tank or water heater shall be installed in a drip pan in accordance
with Section 10. 15.9.b.

10.15.9.2 Construction

a. Drip pans shall be watertight and constructed of corrosion-resistant materials. Metallic pans shall
be 24 gage minimum. Non-metallic pans shall be .0625-inch minimum thickness. Pans shall be not less
than I -'/:" deep and shall be of sufficient size to hold the heater without interfering with drain valves,
burners, controls, and any required access.

244

2006 National Standard Plumbing Code-Illustrated

b. High impact plastic pans shall be permitted under gas-fired water heaters where the heater is
listed for zero clearance for combustible floors and the application is recommended by the pan manu-
facturer.

10.15.9.3 Drainage

a. Drip pans shall have dram outlets not less than %" size, with indirect drain pipes extending to an
approved point of discharge, a suitably located indirect waste receptor, or floor drain, or extend to
within 2 to 6 inches above the adjacent floor.

b. Discharge from a relief valve into a water heater pan shall be prohibited.

10.1 5.1 Water Heaters Used for Space Heating

a. Water heaters used for space heating shall be listed for such use.

b. Piping and components connected to a water heater for space heating application shall be suitable for
use with potable water.

c. Where required, a water temperature control valve shall be installed in every combination water heating-
space heating system application to limit domestic hot water temperature to 140°F. The temperature control
device shall be an ASSE 1017 listed device.

10.16 SAFETY DEVICES FOR PRESSURE VESSELS

10.16.1 Tank Protection

a. Pressure vessels used for heating water or storing water at pressures above atmospheric shall be
protected by approved safety devices in accordance with one of the following methods:

1. A separate pressure relief valve and a separate temperature relief valve; or

2. A combination pressure and temperature relief valve; or

3. Either "a" or "b :% above and an energy cut-off device.

4. Tank construction conforming to a standard that does not require a temperature or pressure safety or
relief valve.

10.16.2 Pressure Relief Valves

a. Pressure relief valves shall comply with the applicable codes, standards, and ratings of ASME. ANSI,
andAGA.

b. The valves shall have a relief rating adequate to meet the pressure conditions in the equipment served,
and shall be installed either directly in a top tank tapping or in the hot or cold water piping close to the tank.

c. There shall be no shutoff valve between the pressure relief valve and the tank.

d. The pressure relief valve shall be set to open at not less than 25 p.s.L above the street main pressure or
not less than 25 p.s.i. above the setting of any house water pressure regulating valve.

e. The setting pressure relief valve shall not exceed the rated working pressure of the tank being protected.
See Figure 10.16.6

Comment: If a separate pressure relief valve is installed on a water heater storage tank, there must he no
shutoff valves between it and the pressure tank. Also, there must be no shutoff valve in its discharge line

2006 National Stanclurd Plumbing Code-Illustrated 245

HWj-

NOTE 2

WATER HEATER
SHUT OFF VALVE

PRESSURE
RELIEF VAVLE

WATER
HEATER

HWf-

NOTE 2

TEMPERATURE
RELIEF VAVLE

NO THREADED END

II
AIR GAP

NOTES 1,5,6

^— NOTE 7 »

■ r

-few

WATER HEATER
SHUT OFF VALVE

WATER
HEATER

ft
t

COMBINATION
P & T VALVE

NO THREADED END
- A!R GAP

NOTES
1.5,6

SEPARATE RELIEF VALVES

A COMBINATION RELIEF VALVE

NOTES:

1. Relief valves can discharge to the floor where permitted by the Authority Having Jurisdiction.

2. A shutoff valve in the hot water supply is permitted.

3. Shutoff valves must not isolate relief valves from the tank that they are protecting.

4. Threads are prohibited on the ends of relief valve discharge pipes to prevent the installation of a pipe
cap if the valve begins to leak.

5. Drains or indirect waste pipes that receive the discharge from relief valves must be sized according
to Table 1 0. 1 6.6, based on the size of the relief valve discharge pipe.

The inlet to indirect waste piping must be elevated to establish sufficient static head above the
horizontal portion of the drain to prevent spillage.

Where two indirect waste pipes from relief valves are joined, the cross-sectional area of the common
drain must be equal to or larger than the sum of the areas of the individual waste pipes. Refer to
Section 9. 3.6.b.

Figure 10.16.6
WATER HEATER RELIEF VALVES AND DISCHARGE PIPING

1 0.1 63 Temperature Relief Valves

a. Temperature relief valves shall be of adequate relief rating, expressed in BTU/HR, for the equipment
served.

b. The valves shall be installed so that the temperature sensing element is immersed in the hottest water
within the top 6 inches of the tank.

c. The valves shall be set to open when the stored water temperature reaches a maximum of 210°F. (See
Section 3.3. 10.)

d. The valves shall conform to an approved standard and shall be sized so that when the valve opens, the
water temperature cannot exceed 210°F with the water heating equipment operating at maximum input.
See Figure 10.J6.6

10.16.4 Combination Pressure-Temperature Relief Valves

Combination pressure-temperature relief valves shall comply with all the requirements of the separate pres-
sure and temperature relief valves. (See Section 3.3.10.) See Sections 10.16.2 and 10.16.3

246

2006 National Standard Plumbing Code-fltMStrateJ

•

10.16.5 Tankless Water Heaters

a. Tankless instantaneous water heaters shall have a safety thermal cutout to shutoff the unit in the event of
unsafe high temperature. The pressure and temperature tank protection required by Section 1 0. 1 6. 1 shall not be
necessary unless required by the manufacturer's installation instructions.

b. The outlet temperature control device for tankless water heaters shall be set to supply no more than 140°F
hot water.

10.16.6 Relief VaJye Discharge Piping

a. Piping from the outlet of a relief valve to the point of disposal shall be of a material suitable for potable
water (see Section 3.4). Discharge pipes from temperature relief valves and combination pressure-tempera-
ture relief valves shall be listed in Table 3.4 for hot water distribution, and shall be suitable for conveying
water at 210°F to an open discharge. The pressure rating of the pipe at 210 deg F is not required to equal or
exceed the pressure setting of the relief valve.

b. There shall be no shut-off valve, check valve or other restricting device between a relief valve and the
pressure vessel or piping system being protected.

c. The discharge pipe shall be no smaller than the outlet size of its relief valve^and shall extend to a point of
disposal without valves, traps or rises that would prevent the relief valve from draining by gravity. Discharge
end of the pipe shall not be threaded.

d. An air gap shall be provided where relief valves discharge into an indirect waste pipe, floor drain, trench
drain, service sink, mop basin, laundry sink, standpipe or other approved receptor. The minimum size of fixture
drains or waste pipes that receive the discharge from relief valves shall be as indicated in Table 10.16.6.

e. Where relief valves discharge to the floor, the discharge pipe shall terminate not more than 6 inches nor
less than 2 inches above the floor.

f. If the point of disposal is outside the room or space in which the relief valve is located, an indirect gravity
drain shall be provided from the room or space to the point of disposal. Indirect waste pipes shall be sized
according to Table 10.16.6 and shall be of a material approved for potable water, sanitary drainage or storm
drainage (see Tables 3.4, 3.5, and 3.7). A visible air gap shall be provided in the room or space in which the
relief valve is located.

EXCEPTION: Where water heaters are located above ceilings, the relief valve discharge pipe shall extend
to a point of disposal or indirect waste that is readily observable in an area below the heater.

g. Where two or more relief valves serving independent systems are located in the same area, each shall
be discharged separately. Where such relief valves for independent systems are discharged into a common
gravity drain or indirect waste pipe, the drain or waste pipe shall be sized according to the largest discharge
pipe served.

See Figure 10.16.6

Table 10. 16.6
SIZE OFDRAENS OR WASTE PIPES RECEIVING RELIEF VALVE DISCHARGE

Minimum Drain or
Discharge Pipe Size Indirect Waste Size

3/4" 2"*

I" 3"

1-1/2" 4"

2" 4"

2-1/2" 6"

■EXCEPTION: A laundry sink with 1-1/2" waste pipe.

2006 National Standard Plumbing Codt'-Ilhtxtraied 247

10.16.7 Vacuum Relief Valves

Where a hot water storage tank or an indirect water heater is located at an elevation above the fixture outlets
in the hot water system, a vacuum relief valve shall be installed on the storage tank or heater. See Figure
10.16.7

WATER HEATER
SHUT OFF VALVE

I tXh

VACUUM RELIEF VALVE

~tx

WATER
HEATER ,

COMBINATION
P & T VALVE

DIP TUBE

6" A.F.F.

HW TO FIXTURES
BELOW

WATER HEATER
SHUT OFF VALVE-

. VACUUM RELIEF VALVE

WATER
HEATER

CW
1 L

COMBINATION
P & T VALVE

6" A.F.F.

HW TO FIXTURES
BELOW

TOp p EED HEATER

BOTTOM FEED HEATER

NOTES:

1 . Vacuum relief valves at water heaters prevent vacuum conditions that could siphon water from a
tank, causing it to be damaged from dry firing or collapse.

2. Vacuum relief valves are tested and rated under ANSI Z21 .22 - Relief Valves for Hot Water Supply
Systems.

3. Backflow prevention vacuum breakers are not intended for use as vacuum relief valves.

4. Vacuum relief valves must be mounted higher than the tank being protected.

Figure 10.16.7
VACUUM RELIEF VALVES ON OVERHEAD WATER HEATER TANKS

10.16.8 Replacement of Relief Valves

a. Relief valves shall be maintained in proper working order and shall be replaced when necessary.

b. Whenever a water heater is replaced, its temperature relief valve and pressure relief valve, or combina-
tion temperature-pressure relief valve shall also be replaced and shall not be reused.

248

2006 Nutiunai Standard Plumbing Codt-lthtsivtHet}

•

10.17 MANIFOLD-TYPE PARALLEL WATER DISTRIBUTION SYSTEMS

10.17.1 General

a. Parallel water distribution systems shall provide individual hot and cold water lines from a manifold to
each fixture served.

b. Manifolds shall be specifically designed and manufactured for parallel water distribution.

c. Manufacturer's of such systems shall provide complete sizing and installation instructions, including any
limitations or restrictions on use.

d. Piping materials shall include coiled plastic or copper tube approved for hot and cold water distribution.

10.17.2 Sizing

See Appendix B for sizing manifolds and distribution lines. Distribution line sizes shall be as recommended by
the system manufacturer to provide the fixture water flow rates listed in Section 10.14.2a. The minimum line
size shall be 3/8" nominal.

10.17.3 Valving

a. Each manifold outlet shall be equipped with a shut-off valve that identifies the fixture being supplied.
Additional shut-off or stop valves at the fixtures shall be provided as required per Section 1 0. 1 2.4.
EXCEPTION: Additional shut-off or stop valves at the fixtures shall not be required if the manifold is located
within the same room or adjacent closet as the fixtures.

b. Manifolds shall be readily accessible.

10.17.4 Support

a. Tube bundles for manifold systems shall be supported in accordance with Chapter 8 of this Code.

b. Supports at changes in direction shall be in accordance with the manufacturer's recommendations.

10.18 DRINKING WATER TREATMENT UNITS

10.18.1 Compliance with Standards

Drinking water treatment units shall comply with the standards listed in Table 3.1.3.

10.18.2 Air Gap Discharge

Discharge from all drinking water treatment units shall be installed with an air gap.

EXCEPTION: Reject water connections from reverse osmosis drinking water treatment units shall be

through an air gap or alternate air gap device in accordance with the requirements of NSF 58.

10.18.3 Connection Tubing

The tubing to and from the drinking water treatment unit shall be of a size and material as recommended by
the manufacturer. The tubing shall comply with NSF 14, NSF 58 or NSF 61.

10.19 SIZING OF RESIDENTIAL WATER SOFTENERS

Residential-use water softeners shall be sized per Table 1 0. 1 9.

•

2006 National Standard Piumhin" Cudc-lllustrated 249

TABLE 10.19
SIZING OF RESIDENTIAL SOFTENERS

•

Required Size of Softener Connection (in.) Number of Bathroom Groups Served

3/4 Upto2 2

] Up to 4 3

1 Installation with a kitchen sink and dishwasher, laundry tray and automatic clothes washer.

2 An additional water closet and lavatory shall be permitted without an increase in sizing.

3 Over four Bathroom Groups, the softener shall be engineered for the specific installation.

250 2006 National Slumlord Plumbing Cude-lllusirated

•

Chapter 11

Sanitary Drainage Systems

1T.T MATERIALS

See Section 3.1.

11.2 BUILDING SEWERS

1 1 .2.1 Sewer or Drain in Filled Ground

Building sewers or building drains that are installed in filled or unstable ground shall be installed in accordance
with Section 2.6.

11 .2.2 Existing Building Sewers and Drains

Existing building sewers and drains may be used in connection with new building sewer and drainage systems
only when found by examination to conform to the new system in quality of material prescribed by this Code.

11.2.3 Building Sewer and Building Drain Size

The size of the building sewer and the size of the building drain shall be determined by fixture unit loads
connected in accordance with Table 1 1.5.1 A. See Figures M.5.] - A and - B

11.3 DRAINAGE PIPING INSTALLATION

1 1 .3. 1 Slope of "Horizontal Drainage Piping

a. Horizontal drainage piping shall be installed in uniform alignment at uniform slopes not less than 1/4 inch
per foot for 2-inch size and smaller, and not less than 1/8 inch per foot for 3-inch size and larger.

b. Where conditions do not permit building drains and sewers to be laid with slope as great as that specified,
a lesser slope may be permitted by the Authority Having Jurisdiction. See Appendix K for the approxi-
mate discharge rates and flow velocities in drains at various slopes.

1L4 FIXTURE UNITS

11.4.1 Load on Drainage Piping

The load on drainage system piping shall be computed in terms of drainage fixture unit values in accordance
with Table 1 1 .4.1 and Section 1 1.4.2.

11.4.2 Conversion of Flow in GPM to DFU

Where the discharge rate of fixtures or equipment is expressed in gallons per minute (GPM). two (2) drainage
fixture units (DFU) shall be allowed for each gallon per minute (GPM) of flow.

2006 National Standard Pltimbinu Code-flfustroied

251

Table 11-4.1
DRAINAGE FIXTURE UNIT (DFU) VALUES

HEAVY-USE ASSEMBLY

TYPE OF FIXTURES OTHER THAN DWELLING UNITS

SERVING 3 OR MORE DWELLING UNITS

IMDIVTDUAI DWrLLINC, I /NITS

Y^A"tMR€OMC;R#?S HAVING &&£.' * ,:

; y Ga^ixy^AN^ w^Tlg closets -f /•

>£-. \

"» SPSS-"

Half bath 01 Powder Room

■. u

1 Bathroom Gioup

5 U

1 ! / 2 Bathrooms

2 Bathrooms

2 l / 2 Bathrooms

3 Bathrooms

Each Additional 'A Bath

Each Additional Bathroom Group

aATHROO^iGKOtrPSjRAYlKaKfiGPF . .

il§I

ggjyj

Half-bath or Powder Room

3 5

\ ;-,

^ ."

[ Bathroom Group

5 5

"! -i

1 [ 1 2 Bathrooms

6 5

2 Bathrooms

7 5

2 V 2 Bathrooms

3 Bathrooms

( js

Each Additional '/ r Bath

Each Additional Bathroom Group

BATHROOM GROUPS HAVING 3.5 GPF
TANK-TVnCWATJSRCLOSrrS- .

Half-baih or Powdei Room

1 Bathroom Group

1 v' 2 Bathrooms

2 Bathrooms

2 V? Bathrooms

, ,

3 Bathrooms

Each Additional 'A Bath

Each Additional Bathroom Group

BATH GROUP (1.6 GPF Flushometer Valve)

BATH GROUP (3.5 GPF Flushometer Valve)

252

2006 National Standard Ptumhint> Code~lllu.\irareJ

Table 11.4.1 (Continued)
DRAINAGE FIXTURE UNIT (DFU) VALUES

HEAVY-USE ASSEMBLY

TYPE OF FIXTURES OTHER THAN DWELLING UNITS

SERVING 3 OR MORE DWELLING UNITS

INDIVIDUAL DWELLING UNITS

-'L^fvrouALsmi*iu$ , . ''J7 .?* s: '-

lief

" >Us£L?&!

***$ig

Batlitub oj Combination Barn/Shower, 1 Vi" I rap

l'\

Bidet, 1 V*" Trap

1.0

l.'i

Clothes Washer, Domestic, 2" Standpipe

3.0

3.H

' I

Dishwasher, Domestic, with Independent Drain

2 U

*1i. *

Drinking Fountain or Watercooler

■ * ,

***> >

Food- Waste-Grinder, Commercial, 2" Min Trap

*".. *'

- ' -

->V

Floor Drain. Auxiliary

r '. '

Kitchen Sink, Domestic, with One ! Vi" Trap

^ , :

Kitchen Sink, Domestic, with Food- Waste-Grinder

Kitchen Sink, Domestic, with Dishwasher

^ \

Kitchen Sink, Domestic, with Grinder and Dishwasher

3.0

' <

Laundry Sink, One or Two Compartments, 1 7:?" Waste

2.0

Laundry Sink, with Discharge from Clothes Washer

2.0

• *

Lavatory. I 74" Waste

1.0

Mop Basin, 3" Trap

>.,' •

3.0

I J f

Service Sink, 3" Trap

3.0

Shower Stall. 2" Trap

2.0

Showers. Group, per Head (Continuous Use)

5.0

Sink. 1 ] h" Trap

2.0

Sink, 2" Trap

3.0

Sink, 3" Trap

5.0

Trap Size. 17/' (Other)

1.0

Trap Size, Vh" (Other)

2.0

Trap Size, 2" (Other)

3.0

' ^

Trap Size, 3" (Other)

5.0

Trap Size, 4" (Other)

6.0

**' v "t

Urinal, 1.0 GPF

4.0

Urinal. Greater Than 1.0 GPF

5.0

6.0

Wash Fountain, 1 '<V' Trap

2,0

Wash Fountain. 2" Trap

3.0

» ,~ t

Wash Sink. Each Set of Faucets

2.0

•5- ■

2006 National Standard Plumbing Coilc-fttiisirtned

253

Table 11.4.1 (Continued)
DRAINAGE FIXTURE UNIT (DFU) VALUES

HEAVY-USE ASSEMBLY

TYPE OF FIXTURES OTHER THAN DWELLING U>

«TS

SERVING 3 OR MORE DWELLING UNITS

INDIVIDUAL DWELLING UNITS

Watei Closet, 1.6 GPF Gra\tty or Pressure Tank

3.0

4.0

6.0

Water Closet, 1 .6 GPF Flushometer Valve

3.0

4.0

6.0

Water Closet, 3.5 GPF Gravity Tank

4.0

6.0

8.0

Water Closet, 3.5 GPF Flushometer Valve

4.0

6.0

8.0

Whirlpool Bath or Combination Bath,' Shower, 1 l h" Trap

2.0

NOTES: (Table 11.4.1):

1. A Bathroom Group, for the purposes of this Table, consists of not more than one water closet, up to two lavatories, and either one
bathtub, one bath/shower combination, or one shower stall. Other fixtures within the bathing facility shall be counted separately to
determine the total drainage fixture unit load.

2. A Half-Bath or Powder Room, for the purposes of this Table, consists of one water closet and one lavatory.

3. For unlisted fixtures, refer to a listed fixture having a similar flow and frequency of use.

4. When drainage fixture unit (DFU) values are added to determine the load on the drainage system or portions thereof, round the sum to the
nearest whole number before referring to Tables 1 1.5.1 A, 1 1. 5. IB, or 12.16.6A for sizing the drainage and venl piping. Values of 0.5 or
more should be rounded up to the next higher whole number (9.5 = 1 DFU). Values of 0.4 or less should be rounded down to the next
lower whole number (9.4 = 9 DFU).

5. "Other Than Dwelling Units" applies to business, commercial, industrial, and assembly occupancies other than those defined under
"Heavy-Use Assembly." Included are the public and common areas in hotels, motels, and multi-dwelling buildings.

6. "Heavy-Use Assembly" applies to toilet facilities in occupancies that place heavy, but intermittent, time-based loads on Ihe drainage
system, such as; schools, auditoriums, stadiums, race courses, transportation terminals, theaters, and similar occupancies where queuing is
likely to occur during periods of peak use.

7. Where other than water-supplied fixtures discharge into the drainage system, allow 2 DFU for each gallon per minute (gprn) of flow. <See
Section 11.4 2.)

11.4.3 Diversity Factors

In certain structures such as hospitals, laboratory buildings, and other special use or occupancy buildings
where the ratio of plumbing fixtures to occupants is proportionally more than required by building occupancy
and in excess of 1 ,000 fixture units, the Authority Having Jurisdiction may permit the use of a diversity factor
for sizing branches, stacks and building sewers.

Comment: The Authority Having Jurisdiction may permit the use of a diversity factor in systems where
the number of fixtures per person is higher than normal. A hospital is such an example where toilet
facilities are provided in each patient room for the convenience of the patients. The load on the drain-
age system is created by the number of persons served^ not by the number of plumbing fixtures that are
installed.

254

2006 National Standard Flumhing Cude-tilusriwal

■11.5 DETERMINING DRAINAGE PIPE SIZES

11 .5.1 Selecting the Size of Drainage Piping

Pipe sizes shall be determined from Table 1 1 .5.1 A and 1 1 .5. IB on the basis of the drainage fixture unit load
(DFU) computed from Table 1 1 .4. 1 and Section 1 1 .4. 1 . Sanitary drainage pipe sizes shall not be reduced in
the direction of flow.

EXCEPTION: Drain pipe sizes for individual fixtures shall be not less than the minimum trap size required in
Section 5.2. See Figures 11.5.1 - A and - B

Table 11.5.1A
BUILDING DRAINS AND SEWERS'

Maximum Number of Drainage Fixture Units (DFU) That May Be
Connected to Any Portion of the Building Drain or the Building Sewer.

Pipe Size-
Inches

1/16-Inch

1/8-Inch

Slope Per Foot
1/4-Inch

1/2-Inch

42 2

180

216

390

480

700

840

1,400

1.600

1.920

2,500

2.900

3.500

3,900

4,600

5,600

7,000

8,300

10,000

50 2

250

575

1,000

2,300

4,200

6,700

12.000

1 . Qn-sife sewers that serve more than one building may be sized according to the current standards and specifications
of the Authority Having Jurisdiction for the public sewers.

2. See Sections 11.5.6.d, ll.5.6.e. and ll.5.6.f.

Table 11.5.1B
HORIZONTAL FIXTURE BRANCHES AND STACKS

Maximum Number of

Drainage Fixture Units

(DFU

That May Be

Connected To:

Stacks

with

More Than Three

Anv

One Stack of
Three Branch

Bran

ch Intervals

Pipe Size

Horizontal

Intervals or

Total at One

Inches

Fixture Branch 1

Less

Total

for Stack

Branch Intervals

P/4

172

20 2

48'

72 1

20 3

160

240

500

360

540

1,100

200

620

960

1 ,900

350

1.400

2.200

3.600

600

2.500

3.800

5,600

1.000

3.900

6.000

8,400

1 .500

7,000

Does not include branches of the building drain.
See Section 1 1.5.6.b.
See Section 1 1 5.6.C.

2006 National Standard Plumbing Cede-Hlmiratcd

255

EXAMPLE OF SIZING DRAINAGE PIPING
(Refer to Figures 11.5.1-A and -B)

1. To size the drainage system, start at the top floor and work down to the building drain.

2. Draw a diagram of the system showing the various fixtures.

3. Assign a drainage fixture unit (DFU) value to each fixture or fixture group using Table 11.4.1. Where a
specific fixture type is not listed, use the "Sink" or "Trap Size" values.

4. Size the horizontal fixture branches on each floor using the pipe sizes in Table 11.5.1.B for the number of
DFUs listed in the second column.

5. Size the stacks using the pipe size in Table 11.5.1.B for the number of DFUs listed in columns 3,4, or 5,
depending on the number of branch intervals. Check the limits on DFUs in any one branch interval and
the total for the stack. Size the stack accordingly.

6. For Stack A in Figure 11.5.1-B, each horizontal branch drain has 90 DFU and is 4" size. The stack is
4" size from top to bottom.

7. For Stack B in Figure 11.5.1-B, the horizontal branch drains are all 4" size. Although the total number
of DFUs is the same as Stack A (450 DFU), the lowest branch interval has more than 90 DFU and must
be 5" size. The stack cannot be smaller than any of its branches and thus must be 5" size at the base.
The upper portions of the stack can be 4" size.

8. For Stack C in Figure 11.5.1-B, although the total number of DFUs is less than Stack A and Stack B, the
top horizontal branch drain must be 5" size because it has 200 DFUs. The entire stack must 5" size,
even though 4" would have been adequate for the total number of DFUs.

9. Stack D in Figure 11.5.1-B only has three branch intervals and can be sized using column 3 in Table
11. 5. LB. Each of the 3" horizontal fixture branches is limited to four 1.6 GPF water closets per Section
11.5.6.b. Each branch interval of the 3" stack is limited to four 1.6 GPF water closets and the entire 3"
stack is limited to twelve 1.6 GPF water closets per Section 11.5.6.C. If the number of water closets on
any branch or the stack exceed the limits for 3" pipe, the branch and downstream stack must be in-
creased to 4" size.

10. In Figure 11.5.1-A, Stack A is 4" size with 450 DFUs. In Table 11. 5. LA, Branch A of the building drain
must be 5" size sloped 1/4" per foot. If 1/4" slope cannot be maintained, the branch must be increased to
6" size sloped 1/8" per foot.

11. In Figure 11.5.1-A, Stack B is 5" size with 450 DFUs. In Table 11.5. LA, Branch B of the building drain
can remain 5" size if sloped 1/4" per foot. Otherwise, the size must be increased if run at less slope.

12. In Figure 11.5.1-A, Section B-C of the building drain is 450 + 450 = 900 DFUs. In Table 11.5. LA, it
needs to be 8" size, but the slope can be reduced to 1/8" per foot.

13. In Figure 11.5.1-A, Stack C is 5" size with 404 DFUs. In Table 11.5. LA, Branch C can remain 5" size,
but must be sloped at 1/4" per foot. Otherwise, the size must be increased if run at less slope.

14. In Figure 11.5.1-A, Section C-D of the building drain is 900 + 404 = 1304 DFUs. Section C-D of the
building drain must be at least 8" size because Section B-C is 8" size. In Table 11. 5. LA, 8" size is
adequate at 1/8" or 1/16" per foot slope. Section 11.3.1 requires 1/8" slope for pipe 4" and larger.
However, Table K-l indicates that the velocity in Section C-D when flowing 1/2 full at 1/16" slope is not
less than the 2 feet per second minimum and the reduced slope might be approved by the Authority
Having Jurisdiction.

15. In Figure 11.5.1-A, Stack D is 3" size with 48 DFUs. In Table 11.5. LA, branch D of the building drain
could remain 3" if sloped 1/2" per foot. However, Section 11.5.6a limits it to four 1.6 GPF water closets.
Otherwise, it would have to be increased to 4" size.

16. In Figure 11.5.1-A, Section D-E of the building drain is 1304 + 48 = 1352 DFUs. Section D-E must be
at least 8" size because Section C-D is 8" size. In Table 11.5. LA, 8" size is still adequate for 1352
DFUs.

1 7. In Figure 11.5.1-A, horizontal fixture branch E is 4 + 1+4 + 1= 10 DFUs. In Table 11. 5. LB, the
branch needs to be 3" size. It has less than the allowable number of water closets in Section 11.5.6.b.

18. In Figure 11.5.1-A, the load on the last section of the building drain and the building sewer is 1352 + 10
= 1362 DFUs. The 8" size of Section D-E is still adequate for the final section of the building drain and
for the building sewer.

256 2006 National Standard Plumbing Code-lllustratcd

STACK D

BUILDING DRAIN
BRANCH A

BUILDING DRAIN(B-C)

BUILDING SEWER

HORIZONTAL
FIXTURE BRANCH E

Figure 11.5.1 - A
SIZING BUILDING DRAINS AND SEWERS

2006 National Standard Plumbine Code-lUustraied

257

STACK "A"
I

1 4" - 90 DFU

STACK "B"
I
I

- — 90 DFU -4"
4" -90 DFU

- — 180 DFU -4"
4"- 90 DFU

- — 270 DFU - 4"
4" - 90 DFU

- — 360 DFU -4"
4" - 90 DFU

•450 DFU -4"

TOTAL - 450 DFU

4" - 90 DFU

- — 90 DFU- 4"
4" - 90 DFU

STACK "C"
I

I 5" - 200 DFU

— 180 DFU -4"
4" - 85 DFU

- — 265 DFU -4"
4" - 85 DFU

■350 DFU -4"
5" - 100 DFU

■450 DFU -5"

STACK "D"
I

- — 200 DFU - 5"
4" - 90 DFU

- — 290 DFU - 5"
3" - 18 DFU

- — 308 DFU - 5"
2" - 6 DFU

- — 314 DFU -5"
4" - 90 DFU

TOTAL - 450 DFU

■ 404 DFU - 5"

TOTAL - 404 DFU

3" - 20 DFU

■20 DFU- 3"

3" -8 DFU

■28 DFU -3"

3" - 20 DFU

■48 DFU -3"

TOTAL - 48 FDU

Figure 11.5.1 - B
SIZING DRAINAGE STACKS

258

2006 National Standard Plumbing Code-Illustrated

•

11.5.2 Minimum Size of Soil and Waste Stacks

Soil and waste stacks shall be sized according to Table 1 1 ,5.1 B. based on the number of branch intervals and

drainage fixture unit load.

EXCEPTION: Sections of stacks shall not be smaller than their largest branch connection, except that stack

sizes shall not be reduced in the direction of flow.

See Figure 11.5.2

I
!
I

STACK VENT {NOTE 5)

4" BUILDING DRAIN {NOTE 4)
I

_£ _ 30 D.F.U. 4" HORIZONTAL

FIXTURE BRANCH {NOTE 2)

4" SOIL OR WASTE STACK (NOTE 3)

•

NOTES:

1 . The figure shows a sanitary drainage piping system with one branch interval.

2. The horizontal branch drain with 30 DFU must be 4" minimum size per Table 1 1 .5.1 B.

3. The stack size must be 4" minimum size, even though Table 1 1 .5.1 B indicates that a 3" stack with
one branch interval could handle 48 DFU.

4. The building drain must be 4" minimum size, even though Table 1 1 .5. 1 A indicates that a 3" building
drain could handle 42 DFU at 1/4" slope.

5. The stack vent must be 2" minimum size, which is 1/2 the size of the 4" drainage stack.

Figure 11.5.2
MINIMUM SANITARY DRAINAGE PIPE SIZES

1 1.5.3 Horizontal Fixture Branches and Branches of the Building Drain:

Horizontal fixture branches shall be sized according to Table 1 1.5. IB to the point where they connect to the
building drain or a branch of the building dram. Building drain piping that serves two or more horizontal fixture
branches are branches of the building drain and may be sized according to Table 1 1.5.] A.

1 1 .5.4 Provision for Future Fixtures

When provision is made for the future installation of fixtures, those provided for shall be considered in deter-
mining the required sizes of drain and vent pipes. Construction to provide for such future installation shall be
terminated with a plugged fitting or fittings. See Figure 11.5.4

2006 National Standard Plumbing Cttde-Hiusirated

259

Comment: Drainage or vent piping installed with plugged or capped fittings for the connection of future
fixtures does not constitute a dead end. Such piping should be accessible.

PIPING SIZED FOR
FUTURE FIXTURE

IT""

PLUGGED OR CAPPED
CONNECTIONS FOR
FUTURE FIXTURE

z /

WASTE

Figure 11.5.4
DRAIN AND VENT PROVISIONS FOR FUTURE FIXTURES

11.5.5 Minimum Size of Underground Drainage Piping

No portion of the drainage system installed underground shall be less than two inch pipe size.

EXCEPTION: Condensate waste, tub and shower traps and trap arms, and piping that receives the discharge

from relief valves after an air gap.

11.5.6 Restrictions on the Number of Water Closets on 3" Drains

a. 3" Horizontal Fixture Branches

No more than four water closets or bathroom groups shall be installed on a 3" horizontal fixture branch.
EXCEPTION : Where the water closets are rated 3.5 gallons or more per flush, no more than two water closets
or bathroom groups shall be permitted.

b. 3" Stacks

No more than four water closets or bathroom groups shall be installed within any branch interval of a 3" stack,
and no more than a total of twelve on the stack.

EXCEPTION: Where the water closets are rated 3.5 gallons or more per flush, no more than two water closets
or bathroom groups shall be permitted in any branch interval, and no more than a total of six on the stack.

c. 3" BuHding Drains and Sewers

1 , In single dwelling units, no more than six water closets or bathroom groups shall be installed on a 3"
building drain or building sewer, or branches thereof.

EXCEPTION: Where the water closets are rated 3.5 gallons or more per flush, no more than three water
closets or bathroom groups shall be permitted,

2, In other than single dwelling units, no more than four water closets or bathroom groups shall be
installed on a 3" building drain or building sewer, or branches thereof.

EXCEPTION: Where the water closets are rated 3.5 gallons or more per flush, no more than two water closets
or bathroom groups shall be permitted.

d. Mixed Water Closets on 3" Drains

Where 3" drainage piping serves a mixture of 1 .6 GPF water closets and 3.5 (or higher) GPF water closets,
the 3.5 (or higher) GPF water closets shall be counted as two water closets for the purpose of determining the
total number of water closets on the 3" drainage piping, The drainage fixture unit (DFU) load for each 3,5 (or
higher) GPF water closet shall be as indicated in Table 1 1.4.1

260

2006 National Standard Plumbing Codc-lliusiiawd

•

11.5.7 Stack Size Reduction

a. Stacks shall be sized according to the total accumulated drainage fixture unit load (DFU) at each story or
branch interval.

b. The stack size shall be permitted to be reduced as the DFU load decreases on the upper portion of the
stack.

EXCEPTION: No portion of a stack shall be less than one-half of the required size at the base of the
stack.

11.6 SIZING OF OFFSETS IN DRAINAGE PIPING

11.6.1 Vertical Offsets

An offset in a stack that is 45 degrees or more from horizontal shall be sized as a straight vertical stack in
accordance with Table 1 1. 5. IB. See Figure 11.6.1

FROM UPPER FLOORS

NOTE 2

OFFSET OF 45° OR MORE FROM
HORIZONTAL CAN BE SIZED AS A
STRAIGHT VERTICAL STACK

NOTE 2

7TH FLR

TO LOWER FLOORS
NOTES:

1. Vertical offsets in drainage stacks do not affect the stack size.

2. If a drain stack with ten or more branch intervals above a vertical offset has fixtures or horizontal
branches connected within two feet above or below the offset, a relief vent must be provided for the
lower portion of the stack.

Figure 11.6,1
VERTICAL OFFSETS IN DRAINAGE STACKS

11.6.2 Reserved

1 1.6.3 Offsets Above the Highest Branch

An offset in a stack above the highest horizontal branch drain connection shall not affect the size of the
stack, only the developed length of the stack vent. See Figure 11.6.3

2006 National Standard Plumbing Code~l 11 u.u rated

261

Jd±

HIGHEST

FiXTURE \J S

BRANCH ^

FIXTURE
BRANCH

STACK TO LOWER FLOOR

NOTES:

1 . The offset does not affect the size of the stack, only its developed length.

Figure 11.6.3
OFFSETS IN STACKS ABOVE THE HIGHEST BRANCH DRAIN CONNECTION

11.6.4 Reserved

11.6.5 Horizontal Offsets

a. A stack with an offset of less than 45 degrees from the horizontal shall be sized as follows:
1 : The portion of the stack above the offset shall be sized as a regular stack based on the total number of
fixture units above the offset.

2. The offset shall be sized as a uilding drain (See Table 1 1 .5.1 A).

3. The portion of the stack below the offset shall be sized as the offset or based on the total number of
fixture units on the entire stack, whichever is the larger.

4. A relief vent shall be provided for the offset is required by Section 12.3.3.
See Figure 11.6.5

262

2006 National Standard Piumbmti Code-lllusuaied

VENT STACK

3 FEET MIN

ALTERNATE

YOKE VENT

(NOTE 7)

NOTE 6

i^®

I — OFFSET

NOTES:

1 . A horizontal offset is one that is less than 45 degrees from horizontal.

2. Vents for the branch drains and required cleanouts are not shown in the Figure.

3. The upper portion of the stack (A-B) is sized based on either the total number of drainage fixture
units (DFU) in each branch interval or the total accumulated load on the upper portion of the stack
per Table 11.5.1.B. The stack size can be reduced as it rises, up to 1/2 size in accordance with
Section 11.5.7.

4. The horizontal offset (B-C)must be sized as a building drain per Table 11. 5.1. A, based on the total
drainage fixture units (DFU) above the offset.

5. The lower portion of the stack (C~D) cannot be smaller than the size of the horizontal offset. The
lower portion must be sized based on either the size of the horizontal offset, the total drainage
fixture units (DFU) in each branch interval of the lower portion, or the total accumulated load on the
upper and lower portions of the stack per Table 11 .5. 1 .B, whichever is larger. The stack size can be
reduced as it rises, up to 1/2 size in accordance with Section 1 1 .5.7.

6. The stack offset must be vented The upper and lower portions of the stack can be vented sepa-
rately in accordance with Section 12.3. 3.a.

7. An alternate vent for the lower portion of the stack can be a yoke vent below the offset that connects
to the vent stack at feast 3 feet above the offset. The 3 foot elevation reduces the possibility of
spillover from the drain stack into the vent stack.

Figure 11.6.5
HORIZONTAL OFFSETS IN STACKS

2006 National Standard Plumbing Code-Illustrated

263

11.7 SUMPS AND EJECTORS

11.7.1 Building Subdrains

a. Building sanitary drains that cannot be discharged by gravity shall be discharged into a sump pit from
which the contents shall be lifted and discharged into the building gravity drainage system by automatic
pumping equipment or by an equally efficient method approved by the Authority Having Jurisdiction.

b. Only drains that must be lifted for gravity discharge shall be connected to such sump pits. All other
drains shall discharge by gravity.

EXCEPTION: Existing buildings.

c. Sump pits shall be a minimum of 1 5 inches in diameter and 1 8 inches deep, and be accessible, tightly
covered, and vented.

See Figure 11.7.1

I i

w.c.

BATHTUB

LAV

IT-

w,c.

BUILDING DRAIN

FULL PORT
SHUT OFF VALVE

CHECK VALVE
SEALED COVER

AUTOMATIC SEWAGE
PUMP IN SUMP — ■ — —

STACK CONNECTED TO GRAVITY DRAIN
EVEN THOUGH IT MAY BE MORE
CONVENIENT TO CONNECT IT TO THE
AUTOMATIC PUMP

VENT THRU ROOF OR
COMBINE WITH OTHER
VENTS, SIZE PER SECTION
12.14 AND TABLE 12.14.2 I

LAV

IrN

BUILDING SUB-DRAIN
BELOW SEWER

VENT THRU ROOF OR
COMBINE WITH OTHER
VENTS

W.C.

-J

NOTES:

1 . Sewage pumps and ejectors must have audible, visual, or combination high level alarms per Section
11.7.11.

Figure 11.7.1
A BUILDING SUBDRAIN AND SEWAGE PUMP

1 1.7.2 Reserved

11.7.3 Reserved

11.7.4 Venting

Building subdrain systems shall be vented according to Chapter 12 of this Code.

264

2006 National Standard Plumbing Code-Illustrated

Comment: Sump pits with centrifugal sewage pumps must be vented in accordance with Section 12.14.2
and Table 12.14.2. Pneumatic sewage ejectors must be separately vented according to Section 12.14.3.

11.7.5 Reserved

11.7.6 Grinder Pump Ejector

a. Grinder pumps shall be permitted to be used when approved by the Authority Having Jurisdiction and
installed according to the manufacturer's recommendations.

b. The rated flow velocity for grinder pump discharge piping shall be not less than 2 feet per second.

c. The size of grinder pump discharge piping shall be:

1 . 1-1/4" size for up to 25 gallons per minute.

2. 1-1/2" size for up to 35 gallons per minute.

3. 2" size for up to 65 gallons per minute.

11.7.7 Pneumatic Ejectors

Vents from pneumatic ejectors shall be carried separately to the open air as a vent terminal in accordance
with-SectJon 12.14.2.

1 1 .7.8 Sewage Ejectors or Sewage Pumps

a. A sewage ejector or sewage pump receiving the discharge from a water closet or urinal shall have a
minimum capacity of 20 gallons per minute.

b. The discharge piping from a sewage ejector and sewage pump shall include a back-water valve and a
full-way shutoff valve.

c. Ejectors or pumps in single dwelling units shall be capable of passing a 1-1/2 inch diameter solid.
EXCEPTION: Grinder pumps.

d.In other than single dwelling units, ejectors and pumps shall be capable of passing a 2 inch diameter solid.
EXCEPTION: Grinder pumps.

11.7.9 Individual Fixture Ejector or Pump

a. Individual fixtures other than water closets, urinals, and similar fixtures, may discharge directly into an
approved fixture-mounted ejector or pump, or into receptors having ejectors or pumps.

b. The discharge piping from a sewage ejector or sewage pump for an individual fixture shall be sized on a
hydraulic basis and include a backwater valve and full-way shutoff valve.

c. Direct-mounted equipment may be manually or automatically operated.

d. The installation of manually or automatically operated equipment shall not be subject to the venting
requirements of this Code, but shall be vented only as required for proper operation of the equipment.

e. A vent on the fixture side of the trap may terminate locally in the area served.

f. If the equipment provides a proper water seal, additional traps are not required.
See Figure 11.7.9

1006 National Stunc/anf Plumbing Codr-fffusimieif 265

VENT IF REQUIRED
BY MANUFACTURER

. i I £3 I I r^~v

DIRECT MOUNTED

FLOOR MOUNTED

NOTES:

1 . Individual fixture drain pumps should be installed in accordance with the manufacturer's instructions.

2. Traps and vents should be installed when recommended by the pump manufacturer.

3. Manufacturers generally require screens on the sink outlet and lint filters on washing machine
discharges to prevent clogging the pump.

Figure 11.7.9
INDIVIDUAL FIXTURE DRAIN PUMPS

1 1 .7.10 Macerating Toilet Systems

a. The sump for macerating toilets shall be vented with a 1-1/4" vent.

b. The discharge line from the sump shall be not less than 3/4" size and include a check valve and full-way
shu toff valve.

c. The distance from a macerating toilet system to a gravity drain shall not exceed the recommendations
of the manufacturer of the macerating toilet system

11.7.11 High Water Alarms

All sewage ejector or sewage pump systems shall be provided with an audible, visual, or combination high

water alarm device.

EXCEPTION: Sewage ejectors and sewage pumps serving individual fixtures.

11.8 RESERVED

11.9 BRANCH CONNECTIONS NEAR THE BASE OF STACKS

a. Horizontal branch dram connections shall not be made within 10 pipe diameters downstream from the base
of a stack.

b. A relief vent shall be provided for stacks of five or more branch intervals, either above the base of the stack
or within 10 pipe diameters downstream from the base of the stack.

266

2006 fc'alioihi! Srtmclant Phunbtuy. Code-Illustrated

c. Branch drains shall not connect between the base of a stack and its relief vent.
See Figures 11.9 and 12.3.1

AIR

LIQUID WASTE

STACK

HYDRAULIC JUMP

VARIES TO MAXIMUM
10 X STACK DIAMETER

NOTES:

1 . Because of "hydraulic jump", stable flow does not occur in the horizontal drain until a distance of up
to 1 times the pipe size "D" from the base of the stack.

2. "Hydraulic jump" can completely close the horizontal drain.

3. "Hydraulic jump" can occur in stacks sized for as few as 4 drainage fixture units (DFU).

4. Branch drain connections are prohibited within 1 x "D" of the base of the stack where hydraulic
jump can occur.

Figure 11.9
HYDRAULIC JUMP AT THE BASE OF DRAINAGE STACKS

11.10 BRANCH CONNECTIONS TO OFFSETS IN STACKS

a. Branch drains shall be permitted to connect to a horizontal stack offset, provided thai the connection is not
less than 10 pipe diameters downstream from the upper portion of the stack

b. Where stacks have five or more branch intervals above a horizontal offset, there shall be no branch connec-
tions to the stack within 2 feet above or below the offset.

c. Where stacks having five or more branch intervals above a vertical offset have branch connections to the
stack within 2 fee! above or below the offset, the offset shall be vented as required for a horizontal offset.

11.11 SUDS PRESSURE ZONES

11.11.1 General

Where suds-producing fixtures on upper floors discharge into a soil or waste stack, suds pressure zones shall
exist as described in Section 1 1 .1 1 .2. Fixture or branch drain connections shall not be made to such stacks in
the suds pressure zones except where relief vents complying with Section 12.15 are provided. Suds-producing
fixtures include kitchen sinks, laundry sinks, automatic clothes washers, dishwashers, and other fixtures that
could discharge sudsy detergents.

2000 National Standard Pltrmbing Code-lliii.umti-d

267

Comment #1: The most likely fixtures to create suds pressure problems in drainage stacks are clothes
washers, dishwashers, kitchen sinlis, and laundry sinks. Where liquid wastes in tall buildings include
high-sudsing detergents, the detergent is vigorously mixed with the liquid waste and air in the stack. The
liquid waste is heavier than the suds and does not cany them along with the flow. The suds will settle in
the lower portions of the drainage system, including any horizontal offsets. The air that is flowing with
the liquid waste compresses the suds and builds up pressure in the stack that can blow trap seals if not
relieved. Zones of the drainage and vent piping where suds pressure can exist are described in Section
11.11.2 and illustrated in Figure 11.11.2.

Comment #2: Suds pressure relief vents in Section 12.15 are larger than ordinary vents for drainage
systems because the suds are heavier than air. Suds can weight from 2 to as much as 19 pounds per cubic
foot.

11.11.2 Locations in Stacks Serving Suds-Producing Fixtures

a. Zone 1 - at offsets greater than 45 degrees from vertical. A suds pressure zone shall extend 40 pipe
diameters up the stack above the offset, 10 pipe diameters downstream from the base of the upper portion of
the stack, and in the horizontal offset, 40 pipe diameters upstream from thetop of the.lower portion of the
stack.

b. Zone 2 - at the base of a soil or waste stack. A suds pressure zone shall extend 40 pipe diameters up
the stack above its base.

c. Zone 3 - in the horizontal drain beyond the base of a soil or waste stack. A suds pressure zone shall
extend 10 pipe diameters from the base of the stack. Also, if a turn greater than 45 degrees occurs in the
horizontal drain less than 50 feet from the base of the stack, suds pressure zones shall exist 40 pipe diameters
upstream and 10 pipe diameters downstream from the horizontal turn.

d. Zone 4 - in a vent stack at the base of a soil or waste stack. Where a vent stack connects above or
beyond the base of a soil or waste stack, a suds pressure zone shall extend up the vent stack to a level equal
to the level of the suds pressure zone in the soil or waste stack.

See Figure 11.11.2

268

2006 National Sluruiard Plumbing Cotle-lllustraieJ

ZONE 2:
ABOVE BASE OF STACK

ZONE 3:
BEYOND BASE OF STACK

ZONE 1:
AT STACK OFFSET GREATER THAN 45°

VENT

TOP OF
ZONE 1 OR 2

DRAINAGE STACK

ZONE 1 OR 2

ZONE 3;

AT TURN GREATER THAN 45°

WITHIN 50 FEET OF BASE OF STACK

ZONE 4:
IN VENT AT BASE OF BASE OF STACK

Figure 11. J 1.2
THE LOCATIONS OF SUDS PRESSURE ZONES IN DRAIN AND VENT PIPING

11.11.3 Separate Stacks

Where soil or waste stacks serving suds-producing fixtures extend six or more floors above the base of the
stack or above a horizontal offset in the stack, the lowest four floors above the base or horizontal offset shall
be drained by a separate stack. In the case of a horizontal offset, the separate stack for the four floors above
the offset may be reconnected to the main stack below the offset, provided that the point of connection is not
a suds pressure zone in either stack. See Figure 11.11.3

2006 National Standard Plumbing Code-Iitustnticd

269

BUILDING DRAIN - SIZE "D-4"

NOTE 1

I OFFSET -

SIZE "D-2"

8TH

7TH

6TH

5TH

4TH

3RD

2ND

1 ST

BSMT

NOTE 1

BUILDING DRAIN - SIZE "D-3"

16 TH

15 TH

14 TH

13 TH

12 TH

11 TH

10 TH

9TH

OFFSET- SIZE "D-1"

Figure 1 1.1 1.3

SEPARATE DRAINAGE STACKS FOR LOWER FLOORS

WHERE THERE ARE SUDS PRODUCING FFXTURES ABOVE

270

200b National Standard Plumbing Cnde-lllusnwed

•

NOTES:

1 . There should be no branch drain connections within 1 pipe diameters of the base of a drainage
stack.

2. Portion D-1 of the upper floor offset between the 8th and 9th floors must be sized as a building
drain, based on the DFU load for the upper floors above that portion of the offset.

3. Portion D-2 of the upper floor offset between the 8th and 9th floors must be sized as a building drain
based on the DFU load for all floors above the offset.

4. Portion D-3 of the building drain must be sized based on the DFU load for the drainage stack above
that portion of the building drain.

5. Portion D-4 of the building drain must be sized based on the DFU for the entire drainage stack.

Figure 11.11,3

SEPARATE DRAINAGE STACKS FOR LOWER FLOORS

WHERE THERE ARE SUDS PRODUCING FIXTURES ABOVE

11.11.4 Exceptions

The requirements of Sections 11.11 and 1 2. 1 5 shall not apply to the-following:

a. Stacks that are less than three stories in height.

b. Stacks in individual dwellings having their own building sewer.

2006 National Standard Plumbing Codt-lHustratcd 271

Blank Page

272 200b Nurional Standard Plumbing Code-Illustrated

•

• - . - ■ ■ L' '

Chapter 12

Vents and Venting

12.1 MATERIALS

See Section 3.6.

•

12.2 PROTECTION OF TRAP SEALS

12.2.1 Protection Required

a. The protection of trap seals from siphonage, aspiration, or back-pressure shall be accomplished by the
appropriate use of soil or waste stacks with adequate venting in accordance with the requirements of this
Code.

b. Venting systems shall be designed and installed so that at no time shall trap seals be subjected to a
pneumatic pressure differential of more than one inch of water pressure under design load conditions.

c. If a trap seal is subject to loss by evaporation, means shall be provided to prevent the escape of sewer
gas. (See Section 5.3.6.)

See Figures 12.2. 1-A and-B

r~2

7 _ r

1" NEGATIVE
PRESSURE

1 1/2" TRAP
SEAL REMAINS

NOTES:

(1 ) Trap at rest with 2" trap seal.

(2) Trap subjected to 1 " suction from building drainage piping.

(3) Trap at rest with 1/2" loss of trap seal. Trap will continue to spillover and lose trap seal when
subjected to 1" suction until the trap sea! is reduced to 1". The 2" initial trap seal permits the trap to
withstand 1" suction and still maintain a trap seal of at least 1".

Figure 12.2 J - A
TRAP SEAL REDUCTION FROM 1" NEGATIVE PRESSURE

2006 Notional Standard f/umhiiie CoJe-lllirsrrated

273

-2" MINIMUM
TRAP SEAL

SPILLOVER WHEN
PRESSURE REMOVED
AND FLOW REVERSES

(1) Trap at rest with 2" trap seal.

(2) Trap subjected to 1" positive pressure from building drainage piping.

(3) When pressure is removed, some spillover occurs from the momentum of the trap legs equalizing.

(4) Trap will continue to spillover and lose trap seal when subjected to 1 " positive pressure until the trap
seal is reduced to 1". The 2" initial trap seal permits the trap to withstand 1" positive pressure and
still maintain a trap seal of at least 1".

Figure 12.2.1 - B
TRAP SEAL REDUCTION FROM 1" POSITIVE PRESSURE

12.3 VENTING OF DRAINAGE STACKS

1 2.3.1 Stack Vents and Vent Stacks

a. A vent stack shall be provided for drainage stacks having Five or more branch intervals.

b. Where drainage stacks have five or more branch intervals, the vent stack shall connect to the drainage
stack as a relief vent, either:

1 . To the drainage stack at or below the lowest fixture branch or,

2. To the building drain within ! pipe diameters downstream from the base of the stack.

c. Vent stacks shall also be permitted to be provided for drainage stacks having less than five branch
intervals.

See Figure 12.3.1

•

274

2006 Nahoihil Standard Plumbing Codfi-Uiusuwi'd

1st BRANCH
INTERVAL

2nd BRANCH
INTERVAL

3rd BRANCH
INTERVAL

4th BRANCH
INTERVAL

.VTR

5th BRANCH • <

INTERVAL N

RELIEF VENT CONNECTION
PER SECTION 12.13.1.b(1)

"~»

BUILDING DRAIN

RELIEF CONNECTION

STACK VENT

VENT STACK

1st BRANCH
INTERVAL

2nd BRANCH
INTERVAL

3rd BRANCH
INTERVAL

4th BRANCH
INTERVAL

5th BRANCH
INTERVAL

RELIEF VENT CONNECTION
PER SECTION 12.3.1 (2}

"~l

VTR

— t

TO STACK

BUILDING DRAIN "D" (— H

RELIEF CONNECTION
TO BUILDING DRAIN

STACK VENT

VENT STACK

WITHIN 10 X"D"
PIPE SIZE

Figure 12.3,1

VENT STACKS FOR DRAINAGE STACKS

HAVING 5 OR MORE BRANCH INTERVALS

12.3.2 Relief Vents for Stacks Having Ten or More Branch Intervals

a. Where drainage stacks have ten or more branch intervals, a relief vent shall be provided for each ten
intervals, starting at the top of the stack.

b. The lower end of each relief vent shall connect to the drainage stack as a yoke vent below its tenth
branch interval.

c. The upper end of the relief vent shall connect 1o the vent stack at an elevation not Jess than 3 feet
above the floor level served by the branch interval.

See Figure 12.3.2

2006 National Standard Plumbing Codt-Uhtxtrttttd

275

V.T.R.

1ST BRANCH
INTERVAL

2ND BRANCH
INTERVAL.

3RD BRANCH
INTERVAL

4TH BRANCH
INTERVAL

5TH BRANCH
INTERVAL

6TH BRANCH
INTERVAL

7TH BRANCH
INTERVAL

8TH BRANCH
INTERVAL

9TH BRANCH
INTERVAL

10TH BRANCH-
INTERVAL

11TH BRANCH -
INTERVAL

12TH BRANCH -
INTERVAL

13TH BRANCH -
INTERVAL

14TH BRANCH -
INTERVAL

-4

SOIL VENT
STACK STACK

5th FLOOR

10TH BRANCH
INTERVAL

(

3' MSN

NOTES:

1 . A branch interval is the vertical distance between branch connections to a soil or waste stack,
generally a story height, but never less than 8 feet. The stack has 15 branch intervals.

2. A relief vent is required for the upper ten branch intervals.

3. The relief vent connects as a yoke vent below the 6th Floor branch drain connection and connects
to the vent stack at least 3 feet above the floor on the 6th Floor.

4. The 3-foot vertical rise in the yoke vent keeps pressure surges in the soil or waste stack from
causing spill-over of drainage into the vent stack.

5. Stack relief vents must be the same size as the vent stack. See Section 12.16.4 for sizing vent
stacks.

Figure 12.3-2

RELIEF VENTS FOR DRAINAGE STACKS

HAVING TEN OR MORE BRANCH INTERVALS

276

2006 National Slumlurd Ptumhiny Code-Illustrated

12.3.3 Horizontal Offsets

a. Horizontal offsets in stacks having five or more branch intervals discharging above the offset shall be
vented either:

1 . by considering the stack as two separate stacks, one above and one below the offset, and venting
each separately.

2. by providing a yoke vent from the drainage stack below the offset to the vent stack required by
Section 12.3.1 not less than 3 feet above the offset. This relief vent may be a stack vent for the lower portion
of the drainage stack.

See Figures 12.3.3-A and -B

V.T.R. I

ROOF -y.

TYPICAL FLOOR

RELIEF VENT FOR
UPPER PORTION
OF STACK

^Z-

ALTERNATE RELIEF VENT
CONNECTED BELOW OFFSET

VENT STACK CONNECTION (Note 3)

^-ALTERNATE VENT STACK CONNECTION (Note 3)

NOTES:

1 . The vent stack must be sized for the entire DFU load on the drain stack per Table 12.1 6.4.

2. The relief vents for the upper and lower portions of the drain stack are required to relief backpressure
from the hydraulic effect of the offset. The relief vents must be the same size as the vent stack.

3. The vent stack must connect to the base of the drainage stack, either below the lowest branch
connection above the base of the stack or within 1 pipe diameters downstream from the base of the
stack.

Figure 12.3.3 - A

RELIEF VENTS FOR HORIZONTAL OFFSETS IN DRAINAGE STACKS

HAVING ONE VENT STACK

2006 National Standard Plumbing Cthle-lltusnattd

277

ROOF

V.T.R. |
+-

1—1

=fc

TYPICAL FLOOR

VENT STACK FOR
UPPER PORTION
OF STACK

ROOF iV-T-R-

(Note 5)

-tH

RELIEF VENT (Note 4)

\i •*-}

_- £1

VENT STACK FOR
LOWER PORTION
OF STACK

ALTERNATE RELIEF VENT
CONNECTED BELOW OFFSET

J ^^- VENT STACK CONNECTION {Note 5)

^-ALTERNATE VENT STACK CONNECTION (Note 5)

NOTES:

1 . The drain stack has separate vent stacks for the upper and lower portions of the stack.

2. The vent stack for the upper portion of the drain stack can be sized for only the DFU load on the
upper portion of the stack. Only vents for upper floor fixtures can be connected to the upper vent
stack.

3. The lower portion of the drain stack carries the DFU load of the upper and lower portions of the
stack. Its vent stack must be sized for the entire DFU load on the drain stack.

4. The relief vent for the lower portion of the drain stack must be the same size as the vent stack for
the lower portion of the stack.

5. The vent stacks must connect to the base of each drainage stack, either below the lowest branch
connection above the base of the stack or within 10 pipe diameters downstream from the base of the
stack.

Figure 1233 - B

RELIEF VENTS FOR HORIZONTAL OFFSETS IN DRAINAGE STACKS

HAVING TWO VENT STACKS

278

7006 National Standard Plumbing Cotle-HluxirateJ

12.3.4 Vertical Offsets

Where vertical offsets in drainage stacks having five or more branch intervals above the offset have branch
connections within 2 feet above or below the offset, a relief vent shall be provided for the lower portion of
the stack below the offset.

12.3.5 Vent Headers

Vents may be connected into a common header at the top of one or more stacks and then be extended to the
open air at one point.

12.3.6 Other Use Prohibited

The plumbing vent system shall not be used for purposes other than venting of the plumbing system.

12.4 VENT TERMINALS

12.4.1 Extension Above Roofs

Vent pipes shall terminate not less than 6 inches above the roof, measured from the highest point where the
vent intersects the roof.

EXCEPTION: Where a roof is used for any purpose other than weather protection, vents shall extend at
least 7 feet above the roof and shall be properly supported. See Figure 12.4.1

SEALED AGAINST LEAKAGE
SECTION 4.5, 12.4.2

FLASHING
SECTION 12.4.2

NOTES:

1. Refer to Section 12.5 for provisions to prevent frost closure.

Figure 12.4.1
VENT EXTENSIONS THROUGH THE ROOF

12.4.2 WaterproofFlashings

Vent terminals shall be made watertight with the roof by proper flashing.

12.4.3 Flap Poling Prohibited

Vent terminals shall not be used for the purpose of flag poling. TV aerials, or similar purposes.

2006 National Standard Plumbing Code-Wash <iiied

279

12.4.4 Location of Vent Terminal

a. Vent terminals shall not be located where vapors can enter the building.

b. No vent terminal shall be located directly beneath any door, window, or other ventilating opening of a
building or of another building, nor shall any such vent terminal be within 1 feet horizontally of such opening
unless it is at least 2 feet above the top of such opening.

c. Where a vent terminal is within 10 feet horizontally and less than 2 feet above a ventilation opening
described in Section 12.4.4b and the line-of-sight from the vent terminal to the ventilation opening is inter-
rupted by the continuous ridge of a roof, the ridge shall be at least 2 feet above the top of the opening. Other-
wise, the vent terminal shall comply with Section 12.4.4b.

d. Where a vent terminal is within 10 feet horizontally and less than 2 feet above a ventilation opening
described in Section 12.4.4b and the line of sight from the vent terminal to such ventilation opening is inter-
rupted by a solid wall or solid barrier, the top of the wall or barrier shall be at least 2 feet above the top of the
ventilation opening and the shortest travel distance around the wall or barrier from the vent terminal to the
nearest edge of the ventilation opening shall be at least 10 feet. Otherwise, the vent terminal shall comply
with Section 12.4.4b.

See Figure 12.4.4

AIR INTAKE OR
EXHAUST OPENING

NOTES:

1 . The separation of vent terminals from doors, windows, and air intake and exhaust openings keeps
foul odors from entering the building,

2. The vent terminal is less than 2 feet above the window, but the window is 1 feet or more from the
vent terminal horizontally.

3. The air intake or exhaust opening can be within 1 feet horizontally from the vent terminal if the vent
terminal is 2 feet or more above the top of the opening.

Figure 12.4.4
ALLOWABLE LOCATIONS FOR VENT TERMINALS

12.4.5 Sidewall Venting

Vent terminals shall be permitted to extend through a wall on an existing building. They shall be at least 10
feet horizontally from any lot line. 10 feet above existing grade, and terminate with a corrosion-resistant bird

280

2006 National Standurt! Plumbing Corie-WusiraieJ

screen. Vent terminals shall not terminate under an overhang of a building. They shall be located in
accordance with Section 12.4.4.

12.4.6 Extensions Outside Building

No soil, waste, or vent pipe extension shall be installed on the outside of a wall of any new building, but
shall be carried up inside the building

EXCEPTION: In those localities where the outdoor temperature does not drop below 32°F, the Authority
Having Jurisdiction may approve the installation outside the building.

12.4.7 Flashing Roof Vent Terminals

a. Vent terminals through the roof shall be made watertight to the roof by sealing the flashing to either
the exterior or interior of the vent terminal.

b. Vent terminals that are externally sealed shall employ manufactured vent stack flashing sleeves,
roofcoup,ings,or„o-caulkroofven«flashi„g,

c. Where vent terminals are sealed by counter-flashing over the top of the vent terminal, the counter
flashing shall not decrease the interior free area of the minimum required vent terminal size. Vent
terminals shall be increased at least one pipe size when counter-flashed. Interior counter flashing shall be
sealed gas-tight to prevent the entrance of sewer gas into the building through the flashing.

12,5 FROST CLOSURE

Where the Authority Having Jurisdiction requires protection against frost closure, vent terminals less
than 3" pipe size shall be increased at least one pipe size to not less than 2" size. Where an increase is
necessary, the increase in size shall be made inside the building at least one foot below a roof or ceiling
that is thermally insulated and in an area not subject to freezing temperatures. See Figure 12.5

MINIMUM 3" SIZE

SEALED

WATERPROOF

FLASHING

ROOF

INCREASER FITTING
WHERE NECESSARY

VENT SIZE (See Table 12.16}

L><J

NOTE;

1 . Where pipe size increases are necessary to avoid frost closure, the increase in pipe size must
be one foot below an area subject to freezing temperatures.

Figure 12.5
MINIMUM VENT EXTENSION SIZE TO PREVENT FROST CLOSURE

2006 S'tiritMHi) Srundt/nt Plumbing Codtf-llhtstntlcd

12.6 VENT SLOPES AND CONNECTIONS

12.6.1 Vent Slope

Vent and branch vent pipes shall be free from drops and sags and be sloped and connected as to drain by
gravity to the drainage system. See Figure 12.6.1

VENT MUST NOT ■
FORM A TRAP

BEAM

BACKWARD SLOPE

FORWARD SLOPE

NOTE:

1 . Vent piping that is sloped allows condensation and moisture that may form in the piping to drain to
the drainage system.

2. Ventpiping must not have any trapped sections. Water may collect in trapped piping, fill the piping,
and render the vent ineffective.

3. Vent piping can slope back to the fixture served or forward away from the fixture, as long as it drains
to the drainage system.

Figure 12.6.1
VENT PIPING SLOPE

12.6.2 Vertical Rise

Every vent shall rise vertically to a minimum of 6 inches above the flood level of the rim of the fixture being

served before connecting to a vent.

EXCEPTION:

If a horizontal offset is required in the verticle rise due to existing conditions the horizontal section shall be

installed in accordance with sec. 12.6.2.2.

See Figure 12.6.2-A and-B

282

200b National Standard Plumbing Code-Illustrated

CONNECT VENT TO
SOIL OR WASTE PIPING
ABOVE CENTERLINE

MUST BE ABOVE
CENTER LINE

NOTES:

1 . Connecting the vent above the centerline of a horizontal drain reduces the possibility of the vent
connection being fouled by the flow in the drain.

Figure 12.6.2 - A
VENT PIPE CONNECTIONS TO HORIZONTAL DRAINS

FLOOD LEVEL RIM OF LAVATORY-

•

CTAfK m-

r~"

6"MIN /

~~l ,

sTope*

See EXCEPTION
n Section 12.6.2

VENT

LAVATORY

BATHTUB

•RU

I w.c.

SOIL — *-~^.
STACK ^

TRAP^

(Note 1 )

NOTES:

1 . A separate vent will be required for the bathtub if the developed length of its trap arm exceeds the
maximum allowable length in Table 1 2.8. 1 .

2. If a vent is required for the bathtub, it can have a horizontal offset below the flood level rim of the
bathtub, but it must be 6 inches above the flood level rim of the lavatory before it connects to another
vent. The horizontal offset below the flood level rim must be sloped so that it drains to the drainage
system.

Figure 12.6.2 - B

HORIZONTAL VENT PIPING

BELOW THE FLOOD LEVEL RIM OF FIXTURES

12.6.2.1

Where a vent pipe connects to a horizontal fixture drain branch, and conditions require a horizontal
offset in the vent below the flood level rim of the fixture served, the vent shall be taken off so that the
invert of the horizontal portion of the vent pipe is at or above the centerline of the horizontal soil or
waste pipe.

•

2006 National Standard Plumbing Code-llhisiruted

2o3

12.6.2.2

The portion of the horizontal vent installed below the flood level rim as permitted in Section 12.6.2. 1
shall be installed with the required slope to drain by gravity to the drainage system. See Figure
12.6.2 -B

12.6.2.3

Cleanouts shall be provided in the vent piping so that any blockages in the vent piping below the flood
level rim of the fixture served can be cleared into the drainage system.

12.6.3 Vent Connection Height Above Fixtures

Connections between any horizontal vent pipe, including individual vents, branch vents, relief vents, circuit
vents or loop vents, and a vent stack or stack vent shall be made at least 6 inches above the flood level rim of
the highest fixture on the floor level.

12.6.4 Side-Inlet Closet Bends

a. Side-inlet closet bends shall be permitted only in cases where the fixture connection thereto is vented.

b. In no case shall the side-inlet be used to vent a bathroom group without being washed by a fixture.
EXCEPTION: As allowed in Sections 1 2. 1 and 1 2. 1 1 .

12.7 ADJACENT FIXTURES

Two fixtures set adjacent within the distance allowed between a trap and its vent, may be served with one com-
mon vent, provided that each fixture connects separately into an approved double fitting having inlet openings at
the same level. (See Section 12.9.2 for inlet openings at different levels.) See Figure 12.7

Comment: Suitable double fittings for connecting adjacent fixtures such as lavatories, sinks, tubs, showers,
urinals, or floor-outlet water closets to u stack are double sanitary tees, double fixture fittings (plastic), and
sanitary crosses. These fittings have high branch openings into the stack that keep the top of the vent
opening above the weir of the traps to prevent self-sip honage.

•

COMMON VENT

SANITARY CROSS OR
DOUBLE SANITARY TEE

Figure 12.7

VENTING ADJACENT FIXTURES

CONNECTED TO A VERTICAL DRAIN AT THE SAME LEVEL

284

2006 National Standard Plumbing Code-llluxtrateJ

•

12.8 FIXTURE VENTS

12.8.1 Venting of Fixture Drains

Fixture drains shall have a vent so located that the vent connects above the top weir of the trap and the

developed length of the trap arm is within the limits set forth in Table 12.8. 1 .

EXCEPTIONS:

(1 ) Water closets and similar siphonic fixtures.

(2) Combination waste and vent systems, (see Section 12.17)

(3) Vents may be connected below the top weir of the fixture trap if the following conditions are met:

a) The vertical section of the drain pipe shall be at least one pipe size larger than the trap inlet size.

b) The horizontal pipe connected to the trap outlet shall be at least two pipe diameters long.

c) The developed length of the trap arm shall not exceed the values in Table 12.8.1.
See Figures 12.8.1-A and-B

•

VENT

INSIDE WALL OF PIPE
TOP OF VENT OPENING

• WASTE

NOTES:

1 . Trap arm lengths are limited by Table 1 2.8. 1 to prevent self-siphonage of the fixture trap.

2. The top of the opening at the vent pipe must not be below the elevation of the trap weir. The
maximum trap arm lengths in Table 12.8.1 are based on using sanitary tees or other short turn
fittings to connect trap arms to the drainage system. Long turn fittings should not be used with
Table 12.8.1.

3. The trap arm length is the developed length along its centerline, including any changes in direction.

Figure 12.8.1 - A
THE MAXIMUM LENGTH OF TRAP ARMS

Table 12.8.1
MAXIMUM LENGTH OF TRAP ARM

Diameter of Trap
Ann (Inches)

Length — Trap to Vent

Slope — Inches per Foot

174

2
3

3'6"
5'
8'
10'
12'

NOTE: This table has been expanded in the "length" requirements to reflect expanded application of the wet venting principles. Slope shall not
exceed 1/4" per loo!.

2006 National Standard Plumbing Cotk-lihtstruicd

285

VENT

CONNECTED
ABOVE
WEIR OF
TRAP

"C"

"A"

•

EXAMPLE OF
EXCEPTION #3

NORMAL VENT
CONNECTION
NOTES:

1 . "A" is the trap pipe size.

2. "B" is the horizontal pipe between the trap outlet and the vertical leg. Its length must be at least
two times the trap pipe size to avoid creating an "S" trap.

3. "C" is the vertical drop. It must be one size larger than the trap pipe size.

4. "D" is the connection to a vented drain line. The horizontal portion of "D" must be the same size as
"C". The distance from the weir of the trap to the vent connection at "D" must be within the limits of
Table 12.8.1, based on the size of the trap.

Figure 12.8.1 - B
EXAMPLES OF EXCEPTION #3 TO SECTION 12.8.1

(VENT CONNECTIONS BELOW THE WEIR OF A TRAP)

12.8.2 Provision for Venting Future Fixtures

On new construction of residential dwelling units with basements, a 2" minimum size vent shall be installed
between the basement and attic or tied into an existing, properly sized vent and capped for future use.

1 2.8.3 Crown Venting Limitation

A vent shall not be installed within two pipe diameters of the trap weir. See Figure 12.8.3

VENT

INSIDE WALL OF PIPE

TRAP WEIR

WASTE

NOTES:

1 . Vents connected too close to the crown or weir of a trap are subject to clogging, thereby rendering
the vent ineffective. Vent connections must be at least two pipe diameters from the weir of the trap.

Figure 12.8.3
CROWN VENTS ARE PROHIBITED

286

2006 National Standard Plumbing Cotle-Ilfustraied

•

12.8.4 Water Closets and Other Siphonic Fixtures

For water closets and other fixtures that operate by siphonic action, the distance between the outlet of the
fixture and its vent connection shall not exceed 3 feet vertically and 9 feet horizontally.

12.9 COMMON VENTS

12.9.1 individual Vent as Common Vent

An individual vent, installed vertically, may be used as a common vent for two fixture traps when both fixture
drains connect with a vertical drain at the same level.

12.9.2 Fixtures Drains Connected at Different Levels

A common vent may be used for two fixtures installed on the same floor but connecting to a vertical drain at
different levels, provided that the vertical drain is one pipe size larger than the upper fixture drain but in no
case smaller than the lower fixture drain. See Figure 12.9.2

T
V

1 DFU

1 1/4" _/ ^

3 DFU

*/~

NOT LESS THAN 1 1/2"

COMMON VENT
1 DFU

| /- COMMON VENT

3" (Note 1)

1 1/4"

1 DFU

1 1/4*

1 DFU

1 1/4'

!/"

2" (Note 1)-

COMMON VENT
3 DFU

NOTES:

1 . When the upper fixture is 3 DFU and the lower is 1 DFU, the vertical drain must be 3" instead of 2"
so that the 1 DFU fixture is wet vented during the heavier discharge from the 3 DFU fixture.

Figure 12,9.2

VENTING FIXTURES CONNECTED TO A

VERTICAL DRAIN AT DIFFERENT LEVELS

12.10 WET v EN tt NG

12.10,1 Single Bathroom Groups

a. An individually vented lavatory in a single bathroom group shall be permitted to serve as a wet vent for
either the water closet, the bathtub or shower stall, the water closet and bathtub/shower if all of the following
conditions are met.

1 . The wet vent is 1-1/2" minimum pipe size if the water closet bend is 3" size or it shall be 2" minimum
pipe size if the water closet bend is 4" pipe size.

2. A horizontal branch drain serving both the lavatory and the bathtub or shower stall is 2" minimum pipe
size.

2006 Narionaf Standard Plumbing Coik-Illuxtniied

287

3. The length of the trap arm for the bathtub or shower stall is within the limits of Table 12.8.1. If not, the
bathtub or shower stall shall be individually vented.

4. The distance from the outlet of the water closet to the connection of the wet vent is within the limits
established by Section 12.8.4. Otherwise, the water closet shall be individually vented.

5. A horizontal branch serving the lavatory and the bathtub or shower stall shall connect to the stack at
the same level as the water closet, or it may connect to the water closet bend, or the lavatory and bathtub or
shower stall may individually connect to the water closet bend.

6. When the bathroom group is the topmost load on a stack, a horizontal branch serving the lavatory and
the bathtub or shower stall may connect to the stack below the water closet bend, or the lavatory and the
bathtub or shower stall may individually connect to the stack below the water closet bend.

See Figures 12.10.1-A through-C

1 1/2"

TUB/SHOWER

STACK
VENT

NOTES:

1. The vent for the bathroom group is 1-1/2", which is 1/2 the size ofthe 3" drain for the bathroom
group.

Figure 12.10.1 - A

A WET VENTED BATHROOM GROUP WITH A 3" CLOSET BEND

(SINGLE STORY OR TOP FLOOR)

STACK -
VENT

TUB/SHOWER

5'-0" MAX IF 1 1/2"
8'-0" MAX IF 2"

WATER CLOSET

NOTES:

1 . The vent for the bathroom group is 2", which is 1 12 the size of the 4" drain for the bathroom group.
Even though the bathroom group could have had a 3" drain with a 1-1/2" vent, installing a 1-1/2" vent
on the 4" drain would cause unnecessary confusion for the installer and inspector.

Figure 12.10.1 - B

A WET VENTED BATHROOM GROUP WITH A 4" CLOSET BEND

{SINGLE STORY OR TOP FLOOR)

288

2006 National Slumlord Plumbing Coiie-lllustratcJ

STACK
VENT

TUB/SHOWER

5'-0" MAX IF 1 1/2'
8'-0" MAX IF 2"

WATER CLOSET

Figure 12.10.1 - C

A WET VENTED BATHROOM GROUP WITH 3" OR 4" CLOSET BEND

(SINGLE STORY OR TOP FLOOR)

12.10.2 Double Bathtubs and Lavatories

Two lavatories and two bathtubs or showers back-to-back may be installed on the same horizontal branch
with a common vent for the lavatories and with no back vent for the bathtubs or shower stalls provided the
wet vent is 2" in size and the lengths of the tub/shower drains conform to Table 12.8. 1 . See Figure 12.10.2

WATER CLOSET

LAVATORY

TUB

5'-0" MAX IF 1 1/2"
8-0" MAX IF 2"

WATER CLOSET

Figure 12.10.2

WET VENTED BACK-TO-BACK BATHROOM GROUPS

(SINGLE STORY OR TOP FLOOR)

12.1 0.3 Multi-Story Bathroom Groups

a. On the lower floors of a stack, the waste pipe from one or two lavatories may be used as a wet vent for
one or two bathtubs or showers as provided in Section 1 2. 1 0.2.

b. Each water closet below the top floor shall be individually back vented.

EXCEPTION: The water closets in bathroom groups shall not be required to be back vented if the follow-
ing conditions are met;

2006 National Standard Plumbing Code-llhtsrrttied

289

1 . The 2" waste serving the tubs/showers and lavatories connect directly into the water closet bend with a
45° wye tap in the direction of flow or,

2. A special stack fitting is used that consists of a 3" or 4" closet opening and two side inlets each 2" in
size and the inverts of which are above the center, and below the top of the water closet opening; and one of
the 2" inlets is connected to the tub/shower drains, and the other is connected to the waste pipe from a
maximum of two lavatories that are vented to a vent stack or stack vent; or,

3. In lieu of the special stack fitting of Section 12.1 0.3b(2) above, 4" closet bends with two 2" wye taps
may be used.

See Figures 12.10.3-A through-E

INDIVIDUAL
BACK VENTS

WATER CLOSET

SOIL STACK

LAVATORY I

TUB/SHOWER

WATER CLOSET

Figure 12.10.3 - A

WET VENTED BACK-TO-BACK BATHROOM GROUPS ON A LOWER FLOOR

WITH BACK VENTED WATER CLOSETS

(ONE ARRANGEMENT)

290

2006 Nations! Standard Plumbing Coik-Hluxtmteil

5'-0" MAX !F 1 1/2"
8'-0" MAX !F 2"

SOIL STACK-

WATER
CLOSET

Figure 12 .1 03 - B

WET VENTED BACK^TO-BACK BATHROOiM GROUPS ON A LOWER FLOOR

WITH BACK VENTED WATER CLOSETS

f ANOTHER ARR4NGFMFNT1

2" |

LAVATORY' TUB/ —C [

U^ SHOWER I

VENT
STACK

TUB/SHOWER

5'-0" MAX IF 1 1/2"
8-0" MAX IF 2"

3" OR 4"
CLOSET BEND

NOTES:

1. This is an example of Exception #1 to Section 12.10.3.

2. Two adjacent bathroom groups are shown but individual bathroom groups can also be wet vented in
this manner.

3. A lower floor is shown, but the arrangement can be used at the top of a stack.

Figure 12.10.3 - C
ADJACENT BATHROOM GROUPS WET VENTED WITH 45 DEGREE WYE TAPS

2006 National Standard Plumbing Catle-lllttstrated

291

1>£" TRAP

VENT STACK

DETAIL OF
HUBLESS
SPECIAL
STACK FITTING

SPECIAL

STACK

FITTING

NOTES:

1 . This is an example of Exception #2 to Section 12,1 0.3.

2. The side inlets to the special stack fitting are slightly higher than the water closet connection and
the side connection that is wet vented vents all of the fixtures that are connected to the fitting.

3. A lower floor is shown, but the special stack fitting can be used at the top of a stack.

Figure 12.10.3 -D
A BATHROOM GROUP WET VENTED WITH A SPECIAL STACK FITTING

iy 2 " TUB/ SHOWER TRAP

4" C.B.

VENT STACK

iy?" TUB/ SHOWER TRAP

NOTES:

1 . This is an example of Exception #3 to Section 12.1 0.3.

2. The oversized 4" water closet fixture drain permits the tub/shower on one side of the drain to be wet
vented by the lavatory on the other side of the drain.

3. Two adjacent bathroom groups are shown, but individual bathroom groups can be wet vented in this
manner.
A lower floor is shown, but the arrangement can be used at the top of a stack.

Figure 12.10.3 -E
ADJACENT BATHROOM GROUPS WET VENTED WITH 4" CLOSET BENDS

HAVING TWO 2" WYE TAPS

292

2006 Naiioiitil Standard Plumhinx Cotte—I lluximled

12.10.4 Bathtubs and Water Closets

a. An individually-vented bathtub in a single bathroom group shall be permitted to serve as a wet vent for
the water closet if all of the following conditions are met:

1 . The wet vent is 2" minimum size.

2. The distance from the outlet of the water closet to the connection of the wet vent is within the limits
established by Section 12.8.4. Otherwise, the water closet shall be individually vented.

See Figure 12.10.4

SOIL OR
WASTE STACK

SOIL STACK

1%" FOR 3" CLOSET BEND OR BRANCH
2" FOR 4" CLOSET BEND OR BRANCH

TUB/SHOWER
1Kz"TRAP

2" WET VENT

WATER CLOSET
(Note 1}

3" OR 4"

NOTES:

1 . The maximum distance from the water closet outlet to its vent connection is 9 feet horizontal and 3
feet vertical.

2. A lower floor is shown, but the arrangement can be used at top of stack.

Figure 12.10.4
A WATER CLOSET WET VENTED BY A BATHTUB

12.10.5 Waste Stacks in Dwelling Units

In a single dwelling unit, a waste stack that receives the discharge of a kitchen type sink or a 3 dfu fixture
may also serve as a wet vent for a laundry tray or a 3 dfu fixture connected to the stack at the floor below.
The minimum size of the waste stack and wet vent up to the upper branch connection shall be 2" in diameter.
No sink shall be installed on a two-inch wet vent that vents a water closet. See Figure 12.10.5

2006 National Standard Piunibina Code-tltusmuvd

293

UPPER FLOOR

LOWER FLOOR

■1%" MINIMUM

KITCHEN SINK

OR OTHER FIXTURE UP TO 3 D.F.U.

(EXCEPT A WATER CLOSET)

}

2" WET VENT (MIN.)

LAUNDRY TRAY
OR OTHER FIXTURE
(3 D.F.U. MAXIMUM)

}

NOTES:

1 . The arrangement is limited to waste stacks in dwelling units, and cannot serve water closets.

Figure 12.10.5
WASTE STACKS IN DWELLING UNITS

12.11 STACK VENTING

12.11.1 Fixture Groups

a. A single bathroom group and a kitchen sink (with or without a disposer and/or dishwasher) located back-
to-back, or two bathroom groups back-to-back may be installed without individual fixture vents in a one-story
building or on the highest branch of a stack provided that the following conditions are met:

1 . Each fixture dram connects independently to the stack.

2. The tub and/or shower and water closet enter the stack at the same level.

3. The requirements of Table 12.8. 1 are met.

4. A side inlet connection into a 4" closet bend shall be considered to be an independent connection to the
stack.

See Figures 12.11.1-A and-B

294

2006 National Standard plumbing Code-Illustrated

LAVATORY

4" CLOSET BEND
WATER CLOSET

TUB / SHOWER

STACK

NOTES:

1 . The arrangement shown is permitted in a one-story building or at the top of a stack.

2. Each fixture must connect independently to the stack except that the tub/shower connection to the
4" water closet fixture drain is considered to be a connection to the stack because the 4" drain is
oversized for the water closet.

3. The length of all trap arms from their trap weir to their vent opening at the stack must not exceed
the limits in Table 12.8. 1 . The vent distance for the water closet must be in accordance with
Section 12.8.4.

4. Bathroom groups without kitchen sinks can also be stack vented as shown.

Figure 12.11.1 - A
STACK VENTING A BATHROOM GROUP AND AN ADJACENT KITCHEN SINK

•

TUB I SHOWER

VENT THRU ROOF
I

WATER CLOSET

4" CLOSET BEND

NOTES:

1 . The arrangement shown is permitted in a one-story building or at the top of a stack.

2. Each fixture must connect independently to the stack except that the tub/shower connections to
the 4" water closet fixture drains are considered to be connections to the stack because the 4"
drains are oversized for the water closets.

3. The length of all trap arms from their trap weir to their vent opening at the stack must not exceed
the limits in Table 12.8.1 . The vent distance for the water closets must be in accordance with
Section 12.8.4.

4. Bathroom groups without kitchen sinks can also be stack vented as shown.

Figure 12.11.1 - B
STACK VENTING ADJACENT BATHROOM GROUPS AND AN ADJACENT KITCHEN SINK

2006 National Standard Plumbing Cude-flliLitrated

12.11.2 Lower Floors

a. Lower floor bathroom groups may be vented as provided in Section 12.11.1, provided the following
conditions are met:

1. A wye is installed in the stack with an upright one-eighth bend continuing from the wye branch to serve
the stack group.

2. A 2" relief vent is connected to the wye branch at least 6 inches above the flood level rim of the
highest fixture on the wye branch.

See Figures 12.11.2-A and-B

STACK

TUB / SHOWER

VENT STACK

6" MIN.

LAVATORY

FLOOD LEVEL RIM
OF HIGHEST FIXTURE

WATER CLOSET

WITH 4" FIXTURE DRAIN

STACK WYE WITH UPRIGHT % BEND

NOTES:

1 . Each fixture in the stack group must connect independently to the sub-stack except that the
connection to the 4" water closet fixture drain is considered to be a connection to the sub-stack
because it is oversized for the water closet.

2. The length of alt trap arms from their trap weir to their stack must not exceed the limits in Table
12.8.1. The vent distance for the water closet must be in accordance with Section 12.8.4.

Figure 12.11.2 - A
STACK VENTING A BATHROOM GROUP ON A LOWER FLOOR OF A DRAIN STACK

296

2006 National Standard Plumbing Code-llltistmwd

•

VENT JIL
THRU
ROOF l, <-"

TUB/SHOWER

STACK VENTED
TOP FLOOR

STACK VENTED
LOWER FLOOR

WET VENTED
LOWER FLOOR

Figure 12.11.2 - B
STACK VENTED AND WET VENTED BATHROOM GROUPS ON A DRAIN STACK

12.12 FIXTURE REVENTING

12.12.1 Reserved

12.12.2 Horizontal Branches

Three lavatories or one sink within 8 feet developed length of a main-vented line may be installed on a 2"
horizontal waste branch without reventing, provided the branch is not less than 2 inches in diameter through-
out its length, and provided the wastes are connected into the side of the branch and the branch leads to its
stack connection with a grade of not more than 1/4 inch per foot. See Figure 12.12.2

2006 National Standard Pltmihins CoJe-Muurattd

297

STACK VENT

WYE IN STACK WITH UPRIGHT Y B BEND

NOTES:

1 . The horizontal branch must have not more than 8 feet developed length, be 2" minimum size, and
be sloped not more than 1/4" per foot to avoid self-siphonage of the fixture trap.

Figure 12.12.2
FIXTURES ON HORIZONTAL BRANCHES OF A STACK WITHOUT REVENTS

12.12.3 Fixtures without Revents Above Highest Bathtubs and Water Closets

a. Fixtures without revents may be connected to a soil or waste stack above the highest water closet or
bathtub connection if all the following conditions are met:

1 . The total load does not exceed 3 dfu's.

2. The soil or waste stack is 3" or larger.

3. The total load on the stack is in accordance with Table 1 1.5. J B.

4. The waste piping of the fixture above the water closet or bathtub connection is in accordance with
Sections 12.8.1 and 12.12.2.

See Figure 12.12.3

298

2006 National Standard Piumhtni> Cvite-lllustr<ueJ

•

JL_

14" MIN.

4th FLR

3th FLR

2nd FLR

•

1st FLR

2"(N0TEE1)

BATHROOM
GROUP

STACK "A"

BUILDING DRAIN

NOTES:

1 . One or more fixtures totaling up to 3 DFU can be connected to a 3" minimum stack above the highest
bathtub or water closet without individual vents (revents) if the horizontal waste branch(s) from the
fixture(s) is 2" size with 8 feet maximum developed length and sloped no more than 1 14" per foot.

2. The stack must be larger than 3" size if required by Table 11 .5.1 .B.

Figure 12.123
UNVENTED FIXTURES ABOVE THE HIGHEST BATHTUBS AND WATER CLOSETS

12.12.4 VeaitWashdown

a. Fixtures other than kitchen sinks or food-waste-grinders shall be permitted to wash down a vertical loop
vent, circuit vent or relief vent associated with a battery-vented horizontal soil or waste branch without
reventing, provided that:

1. Not more than 2 drainage fixture units are drained to a 2" vent, nor more than 4 drainage fixture units are
drained to a 3" vent;

2. The fixture trap arm lengths comply with Section 1 2.8. 1 ;

3. The fixtures drained to the vent are within the same branch as the other fixtures served by the vent; and

4. No other fixtures are drained to the vent.

2006 National Standard Phmrhins Code-Illustrated

299

12.13 CIROTIT AND LOOP VENTING

12.13.1 Battery Venting

a. A maximum of eight floor-outlet water closets, showers, bathtubs, or floor drains connected in battery
on a horizontal branch drain shall be permitted to be battery vented.

EXCEPTION: Blowout type water closets.

b. Each fixture drain shall connect horizontally to the horizontal branch drain being so vented.

c. The horizontal branch drain shall be considered as a vent extending from the most downstream fixture
drain connection to the most upstream fixture drain connection.

d. Back-outlet water closets shall be permitted to be battery vented provided than no floor-outlet fixtures
are connected to the same horizontal branch drain.

EXCEPTION: Back-outlet blowout type water closets.

e. The battery vent shall be a circuit or loop vent connected to the horizontal branch drain between the two
most upstream fixture drains and shall be installed in accordance with Section 12.6.

f. The entire length of the vent section of the horizontal branch drain shall be uniformly size for the total
drainage discharge connected thereto.

g. The maximum slope of the horizontal branch drain shall be 1 inch per foot.

h. A relief vent shall be provided on battery-vented horizontal branch drains on lower floors that have four
or more water closets connected.

i. The relief vent shall connect to the horizontal branch drain between the stack and the most downstream
fixture drain connection.

j. Relief vents shall be installed in accordance with Section 12.6.

k. Circuit, loop, and relief vents shall be permitted to be a fixture drain or fixture branch for fixtures
located within the same branch interval as the battery-vented horizontal branch drain.
EXCEPTION: No more than four drainage fixture units (DFU) shall discharge to the vent. (See Section
12.12.4).

1. Lavatories and similar fixtures shall be permitted to connect to the horizontal branch drain, either hori-
zontally or vertically .
EXCEPTIONS:

( 1 ) Fixtures that are not located on the same floor as the battery-vented fixtures.

(2) Fixtures that do not have an individual, common, or continuous vent.

m. Batteries of more than eight battery-vented fixtures shall have a circuit or loop vent for each group of
eight or less fixtures.

n. Where there are two or more groups of battery-vented fixtures, the horizontal branch drain for each
downstream group shall be sized for the total discharge into that group, including all upstream groups and the
fixtures within the group being sized.
See Figure 12.13.1 and the definitions of "Battery of Fixtures", "Vent, Circuit", and "Vent, Loop".

300 2006 National Standard Plumbing Code-Illustrated

LOOP VENT

T VENT
•y^STACK

CIRCUIT VENT

RELIEF VENT
NOT REQUIRED

NOTES:

1. Battery vented horizontal branch drains can serve a mixture of two to eight water closets, floor
drains, bathtubs, shower stalls, and other floor-outlet fixtures.

2. Battery vented fixtures must connect horizontally to the horizontal branch drain.

3. The entire length of the horizontal branch drain must be sized for the total DFU load for the branch.
The slope of the drain must not exceed 1" per foot.

4. The developed length of fixture trap arms must be within the limits of Table 12.8.1 for the given pipe

5. Lavatories, sinks, and wall-mounted urinals can connect horizontally or vertically to the horizontal
branch drain, but they must be independently vented,

6. Relief vents are required where horizontal branch drains on lower floors serve more than four water
closets.

7. Fixtures are permitted to drain into circuit, loop and relief vents. A 2" vent can drain 2 DFU. A 3"
vent can drain 4 DFU.

8. Back outlet water closets and wall mounted urinals that are battery vented must connect horizon-
tally to the horizontal drain branch.

Figure 12.13.1
CIRCUIT AND LOOP VENTING BATTERIES OF FIXTURES

2006 h'utiunat Standard Pfumbine Code-Hlnsnaivd

301

12.13.2 Joining Parallel Branches

Where parallel branches of up to eight battery-vented fixtures each are joined prior to connecting to a stack
or building drain, the common downstream piping shall be sized for the combined total fixture unit load of
both branches. A relief vent shall be provided on the common downstream piping when the parallel branches
serve a combined total of four or more water closets and connect to a stack receiving drainage from an
upper floor.

12.13.3 Vent Connections

Circuit, loop, and relief vent connections to battery-vented horizontal drain branches shall be taken off at a
vertical angle or from the top of the horizontal drain. See Section 12.6.2.

1 2.1 3.4 Fixtures Back-to-Back in Battery

When fixtures are connected to one horizontal branch through a double wye or a sanitary tee in a vertical
position, a common vent for each two fixtures back-to-back or double connection shall be provided. The
common vent shall be installed in a vertical position as a continuation of the double connection.

12.14 VENTING OF BUILDING SUBDRAIN SYSTEMS

12.14.1 Fixture Venting

Fixtures and gravity drainage piping in a building subdrain system shall be vented in the same manner as a
conventional gravity drainage system and shall be permitted to connect to vent piping for fixtures and gravity
drainage piping that are not part of the subdrain system.

12.14.2 Sump Pits

a. The minimum size and maximum length of vents for atmospheric sump pits shall be as indicated in Table
12.14.2

b. Where subdrain systems utilize pneumatic sewage ejectors, atmospheric sump pits or surge tanks shall be
provided if water closets, urinals, or other fixtures are close enough to the ejector that they will overflow if flushed
while the ejector is discharging.

c. The atmospheric vents from sump pits and surge tanks shall be permitted to be connected to gravity vent
piping for fixtures other than those served by the sump pit.

302 2006 National Standard Plumbing Code-Illustrated

Table 12.14.2

SIZE AND LENGTH 1 OF SUMP VENTS

Diameter

of Vent, (inches)

Discharge Capacity

1-1/4

1-1/2

2-1/2

of Sump Pump

(gpm)

Maximum Eqi

lival

enl Length

of Vent, in Feet

(Given

Below)

N.L. 2

N.L.

NJL

N.L.

270

N.L.

NJL

160

NJL

N.L.

NJL.

N.L.

270

N.L.

150

380

NJL

NJL.

100

250

NJL.

N.L.

150

NP 4

<10^

110

370

N.L.

200

210

N.L.

250

132

NJL.

300

<10 3

380

400

<10 3

210

500

130

1 . Developed length plus an appropriate allowance for effects of entrance losses and
friction due to fittings, Changes in direction, and changes in diameter. Suggested
allowances may be obtained from NBS Monograph 31 or other acceptable sources.
An allowance of 50% of the developed length may be assumed if a more precise value
is not available.

2. No Limit; actual values greater than 500 feet.

3. Less than 10 feet.

4. Not permitted.

12.14.3 Pneumatic Sewage Ejectors

Pressure release vents for pneumatic sewage ejectors shall extend to a vent terminal that is separate from
any gravity system vents. Such pressure release vents shall be of sufficient size to reduce the ejector tank to
atmospheric pressure within 10 seconds, but shall be not less than 1-1/4" pipe size.

12.15 SUDS PRESSURE VENTING

12.15.1 Relief Venting

Where fixture or branch drains connect to a soil or waste stack within a suds pressure zone as described in Section
1 1 . 1 i .2, a suds relief vent shall be provided for the fixture or branch drain. Suds relief vents shall be 2" minimum
size but not less than one pipe size smaller than the drain branch mat they serve. Such relief vents shall connect to
the drain branch between the suds pressure zone and the first fixture trap on the branch. See Figure 12.15.1

Comment: Suds pressure relief vents in Section 12.15 are larger than ordinary vents for drainage
systems because the suds are heavier than air. Suds can weight from 2 to as much as 19 pounds per cubic
foot.

2006 i\'a:iuniif Standard Plumbing Code-lllusinVed 303

VENT

DRAINAGE STACK

RELIEF VENT
(Note 1)

BRANCH DRAIN FROM
ONE OR MORE FIXTURES

DRAIN CONNECTION IN A
SUDS PRESSURE ZONE

(Note 2)

EVEL OF SUDS PRESSURE ZONE

SUDS PRESSURE
ZONE 4

NOTES:

1 . Relief vents must be sized according to Tabie 12.15.1.

2. Relief vents must not connect to a suds pressure zone in a vent stack

Figure 12.15.1
RELIEF VENTS FOR DRAIN CONNECTIONS IN A SUDS PRESSURE ZONE

Table 12,15.1
SUDS PRESSURE RELIEF VENTS

Drain Size

Relief Vein Size

12.15.2 Prohibited Vent Connections

Connections shall not be made within the suds pressure zone of a vent stack that connects at or downstream
from the base of a soil or waste stack, as described in Section 11.1 1.2.d.

12.16 SIZE AND LENGTH OF VENTS

12.16.1 Size of Fixture Vents

a. Vents for individual fixtures shall be sized according to Table 1 2. 1 6,

b. Vents shall be not less than 1-1/4" size nor less than one-half the size of the fixture drain that they
serve.

304

2000 National Standard Flumbmg Code-Illustrated

c. Where a vent pipe serves two or more fixtures, the size of the combined vent pipe shall be based on the
sum of the drainage fixture units (DFU) for all of the drains served.

d. Where the fixtures being vented are not connected to the same drain stack, the stack size used in Table
1 2. 1 6 shall be the equivalent stack size for their total combined DFU load, based on Table 1 1 .5. .1 B.
EXCEPTION: As otherwise provided in this Code.

See Figure 12.16.1 -A and-B

Table 12.16
SIZE AND LENGTH OF VENTS

Size of

drainage stack

or fixture

drain inches

Drainage
fixture

units con-
nected

Diameter of Vent Required (Inches)

1-1/4

1-1/2

2 2-1/2

4 5

Maximum Length of Vent (Feet)

1-1/4

(1)

1-1/2

150

,, .' "•! «,-.

- -

200

. - L - :

■ . .,.

1 1

150

„•

100

1 1 it i

2<i(i

...

101)

6' « I

6(1
50

Si 10

4' m
2mT

100

lfi'KI

200

*0 'in

2^0

*yii(i

500

"i i

\M)

"li(J

'"6
;no

1000
000

.1 .

200

„„

^ i

500

ill

, — .

1100

1 20

22' nj

"no

350

*()

20(i

400

1 100

620

'Ml

125

300

1100

960

''»0

250

1000

1900

""0

200

700

600

150

500

1300

1400

i 40

100

400

1200

2200

h : .o

250

1100

3600

250

800

1000

125

1000

2500

100

500

3800

350

5600 1

250

( I ) The length of the vent is unlimited

200 tj National Slumlord Plumbing Code-flluslnned

305

W MINIMUM-^ T

fy" MINIMUM

NOTES:

1 . Vent s for individual fixtures must be at least 1 /2 of the size of the drain that they serve, but not less
that 1-1/4"

Figure 12.16.1 - A
THE SIZE OF INDIVIDUAL FIXTURE VENTS

V.T.R.

OVERALL LENGTH OF LONGEST
VENT PATH = 100 FEET

PUBLIC

TOILET ROOMS

150 DFU.

PUBLIC

TOILET ROOMS

150D.F.U.

EQUIVALENT DRAINAGE STACK = 5" (300 D F.U.)

NOTES:

1 . Two groups of public toilet rooms are connected to a combined vent.

2. The size of the vent for the 4" drain stack from each group with more than 1 00 DFU must be 3" if the
overall length to the vent terminal is 100 feet. (Table 12.16).

3. The size of an equivalent drainage stack with 300 DFU is 5" (Table 11.5.1 B).

4. The size of the combined vent for the 5" equivalent stack with 300 DFU and 1 00 feet is 4" in Table
12.16

Figure 12.16.1 - B
THE SIZE OF VENTS FOR MULTIPLE FIXTURES ON DIFFERENT STACKS

1 2. 1 6.2 Size of Circuit or Loop Vents

Circuit or loop vents sha)] be not less than one-half the size of the horizontal drainage branch that they serve.
See Figure 12.16.2

306

2006 Nariontl! Standard Plumbing Code- Illustrated

•

RELIEF VENT
(Note 4)

VENT STACK

CIRCUIT VENT
{Note 3}

NOTES:

1 . A lower floor is shown. It requires a relief vent because there are more than 4 water closets on the
branch,

2. The horizontal branch drain is 4" size

3. The circuit vent must be 2" minimum size per Section 12.16.2.

4. The relief vent must be 2" minimum size per Section 12,16.3.

Figure 12.16.2
THE SIZE OF CIRCUIT AND LOOP VENTS

12.163 Size of Relief Vents

a. The size of relief vents for circuit or loop vented branches of the drainage system shall be not less than
one-half the size of the branch drain being served.

b. Relief vents for stacks having ten or more branch intervals and relief vents for horizontal offsets in such
stacks shall be the same size as the vent stack to which they connect.

See Figure 12.16.2

12.16.4 Size of Stack Vents and Vent Stacks

The minimum required size of stack vents and vent stacks shall be in accordance with Table 12.16. For the
purpose of sizing, the length of a vent stack or stack vent shall be the developed length from its lowest
connection with the drainage system to its termination in the open air, including any vent headers.

12.16.5 Vent Headers

a. Vent headers or portions thereof shall be sized according to Table 12.16.

b. The number of fixture units (DFU) used to size vent headers shall be the sum of all fixture units (DFU)
on all stacks served by each section of the header.

c. The developed length of vent headers shall be the longest vent length from the vent connection at the
base of the most distant stack to the vent terminal in the open air.

d. The soH or waste stack size used to size vent headers shall be the equivalent size capable of handling
the fixture unit load (DFU) on the vent header, based on Table 1 1 .5. IB.

2006 National Standard Plumbing Code-IUustrntcd

307

12.16.6 Aggregate Size of Vent Terminals

a. Each building sewer shall be vented by one or more vents extending from the drainage system, or
branches thereof, to the open air above the roof.

b. Stack vents and vent stacks shall be sized according to Table 12.16.4.

c. The aggregate cross-sectional area of all vent terminals serving a sewer shall be not less than the cross-
sectionai area of the minimum required size of the building drain that they serve, at the point where it con-
nects to the building sewer. (See Table 12.16.6 for the cross-sectional areas of pipes).

EXCEPTION: The aggregate cross-sectional area requirement shall be exclusive of any requirements to
prevent frost closure under Section 1 2.5.

d. One or more vent terminals having the aggregate cross-sectional area of a 3 " vent terminal shall be permitted
to vent a 4" building drain if the drainage fixture unit load (DFU) and number of bathroom groups served by the
building drain does not exceed the maximum number allowed on a 3" building drain, as permitted by Section
12.16.6.C

Table 12.16.6
NOMINAL PIPE CROSS SECTIONAL AREA (Sq. Inches)

Nominal Pipe Size (ID)

Cross Sectional Area (sq in.)

I'm

1'/2

2"
V*"

10"

12"

15"

1.2

1.8

.1.1

4.9

7.1

12.6

19.6

28.3

50.3

78.5

I 13.1

176.7

12.16.7 Underground Vent Piping

The minimum size of vent piping installed underground shall be 1 -1/2".

12.17 COMBINATION WASTE AND VENT SYSTEM

12.17.1 Where Permitted

a. A combination waste and vent system shall be permitted only where conditions preclude the installation
of a conventionally vented drainage system as otherwise required by this Code.

b. Combination waste and vent systems shall be limited to floor drains and other floor receptors, sinks,
lavatories, and standpipes.

12.17.2 Trap Size

Traps in a combination waste and vent system shall be the normal size for the particular fixture. See Table 5.2.

12.17.3 Trap Arms

a. Fixtures shall be considered to be vented at the point that they connect to a combination waste and vent
system.

b. Where fixtures have conventionally sized trap arms, the maximum length of the trap arm from the weir
of its trap to the point of connection to the combination waste and vent systems shall be as limited in Table
12.8.1.

•

308

2006 Nauvtuil Standard PlumbiHii Ctide-IllusrraieJ

•

c. In the case of fixtures with above-the-floor outlets, the vertical drop at the end of the trap arm shall
be one size larger than the trap arm and be considered as the beginning of the combination waste and
vent system.

d. Floor-outlet fixtures shall also be permitted to drop into a vertical combination waste and vent that is
at least one size larger than the trap ami.

e. Where a fixture trap arm is sized as a combination waste and vent, its length shall not be limited and
it shall be considered as a branch of the combination waste and vent system.

f. The maximum vertical drop from a fixture trap arm to a horizontal drain below shall be 6 feet.

12.17.4 Pipe Sizing

The piping in a combination waste and vent system shall be sized according to Table 12.17.4, based on
the number of drainage fixture units (DFU) served and the slope of the piping.

EXCEPTION: No pipe shall be smaller than any section of piping upstream, including vertical drops from
trap arms.

Table 12.17.4
PIPE SIZING FOR COMBINATION WASTE AND VENT SYSTEMS

Load

slope
V 8 " per ft

slope
V per ft

slope

V per ft

slope
7 2 " per ft

3 dfu

12dfu

20dfu

180dfu

218dfu

390 dfu

480 dfu

700 dfu

840 dfu

10"

1600 dfu

10"

1920 dfu

12"

10"

12.17.5 Maximum Slope

All piping in a combination waste and vent system shall be horizontal and sloped at not greater than 1/2

inch per foot.

EXCEPTIONS:

(1) Vertical drops at the end of trap amis.

(2) Vertical drops of not greater than 45 degrees from horizontal where the vertical drop is not greater
than 6 feet and the offset is at least 10 pipe diameters from any rum or branch connection.

12.17.6 Branch Connections

a. Connections to mains and branches within combination waste and vent systems shall be made
horizontally at a slope not greater than 1/2 inch per foot.

b. Branch connections shall not be made in vertical drops or offsets.

12.17.7 Minimum Distances

The distance between turns, offsets, and branch connections in combination waste and vent piping shall
be not less than 10 pipe diameters.

2006 National Standard Plumbing Cade-lHi/sinned

309

12.17.8 Connections to Conventional Drainage Systems

a. Combination waste and vent systems shall extend to the point of connection to a conventionally
sized and conventionally vented drainage system.

b. At the point of connection, the pipe size of the conventional system shall be at least as large as the
combination system, and sized to accept the added drainage load from the combination system.

c. Such connection from the combination system to the conventional system shall be made at an angle
above horizontal of not less than 22-1/2 degrees nor more than 45 degrees.

12.17.9 Connection of Individual Fixtures

Where drains from individual fixtures are designed as a combination waste and vent and are connected to
a conventional drainage system, the connection from the fixture to the conventional system shall be made
according to Section 12.17.8.

12.18 ISLAND SINK VENTING

12.18.1 Where Permitted

Island sink venting shall be permitted for sinks and lavatories where the vent pipe cannot rise 6 inches above
the flood level rim of the fixture before turning horizontal. Kitchen sinks in dwelling units with dishwasher
connections, food-waste-grinder connections, or both, shall be permitted to be island vented. Also see section
12.8.1 (3).

12.18.2 Arrangement of Vent Piping;

The island vent pipe shall rise vertically under the sink at the end of the fixture trap arm to at least 4 inches
above the outlet of the fixture. The vent shall then turn downward and connect to the horizontal drain line
below the floor downstream from the fixture drain connection so that the vertical vent drop wil I drain by gravity
to the drainage system. A horizontal vent pipe shall be extended under the floor from the vertical vent drop
to a point where it can rise vertically. The vertical rise at the end of the horizontal vent portion shall extend
upward to at least 6 inches above the flood level rim of the fixture being vented before turning horizontal and
connecting to a vent to the outdoors. The horizontal portion of the vent under the floor shall pitch back to the
sink so that it will drain by gravity through the vertical vent drop connection to the drainage system.

12.18.3 Size of Island Vent Pipes

Island vent pipes shall be sized as individual or common vents in accordance with Section 12.16.1.

12.18.4 Cleanouts Required

Cleanouts shall be provided in the vertical vent drop under the sink and in the vertical rise beyond the
horizontal portion of the vent so that any blockages in the vent piping can be rodded into the drainage system.

12.19 OTHER DESIGNS

Venting systems not described in this Code may be permitted by the Authority Having Jurisdiction if they
provide the protection required by Section 1 2.2.1 and are individually designed by a licensed professonal
engineer. (See Appendix E - SPECIAL DESIGN PLUMBING SYSTEMS.)

•

310 2006 NarioiHi! Standard Plumbing Cixic-lllusiraicJ

•

Chapter 13

Storm Water Drainage

13.1 GENERAL

13.1.1 Where Required

Roofs, paved areas, yards, courts, and courtyards shall be drained to either a storm sewer where available, a
combined sewer where necessary, or to a place of disposal satisfactory to the Authority Having Jurisdiction.
EXCEPTION: Storm water from one- and two-family dwellings may be discharged on lawns orstreets
provided that the storm water flows away from the dwelling and does not otherwise create a nuisance.

13.1.2 Storm Water Drain age to Sewer Prohibited

Storm water shall not be drained into sewers intended for sewage only, except as approved by the Authority
Having Juri sdi c tion .

Comment #i: The peak storm water flows in combined sanitary and storm sewer systems can overload
the sewage treatment facility, causing it to bypass untreated seivage into its point of discharge.

Comment #2: In many cities with combined sewers, it is impractical to install separate sewers in the
downtown areas because of the number of existing utilities under the streets.

Comment #3: Some jurisdictions with combined savers require that new or renovated buildings have
separate sanitary and storm building drains so that they could be connected to separate sewers in the
future.

13.1.3 Sanitary and Storm Sewers

Where separate systems of sanitary drainage and storm water are installed in the same property, the storm
and sanitary building sewers and drains may be laid side by side in the same trench.

13.1.4 Reserved

13.1.5 Foundation Drains

a. Foundation drains shall be provided around the perimeter of basements, cellars, crawl spaces or any
building space below grade. The drains shall be positioned either inside or outside of the footings, and shall be
of perforated or open-joint approved drain tile or pipe not less than 3" pipe size. The invert of foundation
drains shall be not less than 2 inches below the underside of the floor slab being protected.

b. Foundation drains shall be laid in a filter bed of gravel, crushed stone, slag, approved 3/4" crushed
recycled glass aggregate, or other approved porous materials. The bottom of the filter bed shall be no higher
than the bottom of the base course beneath the floor slab. There shall be not less than 2 inches of filter bed

2006 National Standard Plumbing Cou'e-lllustiattJ

311

beneath the foundation drain. Where foundation drains are located outside of the footings, there shall be at
least 6 inches of filter bed above the top of the pipe.

c. Drainage from foundations shall be discharged to a storm drain, street, alley, approved water course, or
at grade. When discharged at grade, the point of discharge shall be at least 10 feet from any property line and
shall not create a nuisance.

d. Where foundation drains are below the required point of discharge, one or more automatic sump pumps
shall be provided. The pump or pumps shall have adequate capacity to convey all drainage to its point of
discharge. The minimum pump capacity shall be 15 gallons per minute at the required discharge head. Sump
pits shall be sized to accommodate the pump(s), as recommended by the pump manufacturer, but shall be not
less than 15 inches in diameter nor less than 18 inches deep. Sump pits shall be provided with fitted covers.
Pits shall be located to avoid foot traffic where their covers do not have sufficient strength to carry such
weight. Discharge lines from sump pumps shall be sized according to the design pump capacity and shall be
not less than 1-1/4" pipe size. A check valve shall either be incorporated into each sump pump or be installed
in the discharge line from each sump pump, except that check valves may be eliminated where the discharge
pipe would be subject to freezing. Under such conditions the sump pit shall be adequately sized to prevent
short cycling of the pump.

e. Where sump pumps discharge at grade on unpaved surfaces, the discharge pipe shall extend to a splash
block or equivalent, which shall be designed to contain the discharge, reduce its velocity, and avoid disturbing
adjacent areas. Where necessary, the discharge pipe shall terminate with an elbow to direct the flow along
the splash block. Splash blocks shall be at least 24 inches long.

f. The water supply to water-operated storm water sump pumps shall be protected from backflow in
accordance with Section 10.5.
See Figures 13.1. 5- A and-B

GRADE (Note 3)

FLOOR SLAB

FILTER BED (Note 2)

FILTER BED (NOTE 2)

FOUNDATION DRAIN
3" MINIMUM SIZE

NOTES:

1 . The invert of the foundation drain must be at least 2 inches below the underside of the floor slab.

2. The filter bed must be at feast 2" beneath the bottom of the drain pipe and at least 6" above the top
of the pipe. Installing a filter fabric over the filler bed will keep fine soil particles from clogging the
porous openings in the bed.

3. Foundation drains require the same earth cover as drainage piping.

Figure 13.1.5 - A
A FOUNDATION DRAIN OUTSIDE OF A FOOTING

2006 National Standard Plumbing Cotle-UlustrattJ

•

OUTLET OVER SPLASH BLOCK
OR OTHER APPROVED
POINT OF DISPOSAL

NOTE 1

1 1/4" MINIMUM

CHECK VALVE

SUMP PUMP - PEDESTAL
OR SUBMERSIBLE

FITTED COVER

FOUNDATION DRAIN
SEE FIGURE 13.1 5-A

NOTES:

1 . Where subject to freezing weather, the discharge pipe should be sloped downward so that the outlet
drains by gravity.

Figure 13.1.5 - B
A SUMP PUMP FOR FOUNDATION DRAINS

2006 National Standard Plumbing Code-Uhisinilcd

313

13.1.6 Areaway Drains

a. Drainage shall be provided for open areaways beiovv grade where storm water may accumulate.
Areaways include outdoor spaces that provide access to basements or floor levels of a building that are below
grade. Drains in such areas shall be sized according to Table 13.6.2 and shall include strainers as required for
roof drains or floor drains.

b. Areaway drains shall not connect to a foundation drain.
EXCEPTION: Areaways not exceeding 100 square feet in area.
See Figure 13.1.6

FOUNDATION DRAIN
(Note 1 )

SUMP PUMP
(WHERE REQUIRED)

NOTES:

1 . The foundation drains can be inside or outside of the footings. See Figures 1 3. 1 .5 - A and 13.1.5-
B.

2. The areaway drain can connect to a foundation drain if the size of the areaway (and any adjacent
areas that drain into the areaway) is 1 00 square feet or less. It must discharge separately if the
area being drained is larger than 100 square feet.

3. Drain pipes for areaways must be sized according to Table 1 3.6.2, based on the rainfall rate and the
size of the areaway and any adjacent areas that may drain into the areaway. The minimum drain
pipe sizes are 2" if sloped 1/4 in./ft or more and 3" if sloped 1/8 in. /ft.

Figure 13.1.6
THE ARRANGEMENT OF AN AREAWAY DRAIN

13.1.7 Window Well Drains

Window wells shall be drained as required for areaways, except that window wells not greater than 10
square feet in area shall be permitted to drain into a foundation drain, either directly by means of a 2" mini-
mum size drain, or indirectly through a porous filter bed. See Figures 13.1.7-A and-B

314

2006 National Standard Plumbing Code-Jllusiraicd

•

AREA DRAIN

WINDOW WELL
DRAIN PIPE
(Notes 2 & 3)

PIPED DIRECTLY TO THE SUMP
WINDOW WELL EXCEEDS 10 SQ. FT

FOUNDATION DRAIN
(Note 1)

NOTES:

1 . The foundation drains can be inside or outside of the footings. See Figures 1 3. 1 .5 - A and
13.1.5 -B.

2. The window well drain can connect to a foundation drain if the size of the window well (and any
adjacent areas that drain into the window well} is 10 square feet or less. It must discharge sepa-
rately if the area being drained is larger than 1 square feet.

3. Drain pipes for window wells must be sized according to Table 1 3.6.2, accounting for the rainfall rate
and the size of the window well and any adjacent areas that may drain into the window well. The
minimum drain pipe sizes are 2" if sloped 1/4 in./ft or more and 3" if sloped 1/8 in./ft.

Figure 13.1.7 - A
A WINDOW WELL DIRECTLY DRAINED

AREA DRAIN
OR GRAVEL

BASE

POROUS FILTER

BED (NOTE 2)

FOUNDATION DRAIN
[NOTE 1)

NOTES:

1. The foundation drain must be outside of the footings. See Figure 13.1.5 -B.

2. The porous filter bed must extend from the area drain in the window well to the foundation drain.
Installing a filter fabric between the earth and the filter bed will keep the porous bed from becoming
clogged with fine soil particles.

Figure 13.1.7 - B
A WINDOW WELL INDIRECTLY DRAINED

2006 National Standard Plumbing Code~l{htstrotrd

315

13.1.8 Parking and Service Garages

Storm water drainage from parking and service garages shall be in accordance with Sections 6.3. l.d and
6.3. I.e.

13.1.9 Reserved

13.1.10 Roof Drainage

13.1.10.1 Primary Roof Drainage

Roof areas of a building shall be drained by roof drains or gutters. The location and sizing of drains and
gutters shall be coordinated with the structural design and pitch of the roof. Unless otherwise required
by the Authority Having Jurisdiction, roof drains, gutters, vertical conductors or leaders, and horizontal
storm drains for primary drainage shall be sized based on a storm of 60 minutes duration and 100-year
return period. (See Appendix A)

13.1.10.2 Secondary Roof Drainage

a. Where parapet walls or other construction extend above the roof and create areas where storm
water would become trapped if the primary roof drainage system failed to provide sufficient drainage,
an independent secondary roof drainage system consisting of scuppers, standpipes, or roof drains shall
be provided. Secondary roof drainage shall be sized for a 100-year. 15-minute storm (see Appendix
A). The capacity of the primary system shall not be considered in the sizing of the secondary system.

b. Where secondary drainage is provided by means of roof drains or standpipes, the secondary
system shall be separate from the primary system and shall discharge independently at grade or other
approved point of discharge.

c. Where secondary roof drainage is provided, the overflow level(s) into the secondary system shall
be established by the amount of ponding that is allowed in the structural design of the roof, including
roof deflection. An allowance shall be made to account for the required overflow head of water above
the secondary inlets. The elevation of the secondary inlet plus the required overflow head shall not
exceed the maximum allowable water level on the roof.

d. Scuppers shall be sized as rectangular weirs, using hydraulic principles to determine the required
length and resulting overflow head (see Appendix A). Secondary roof drains and standpipes shall be
sized according to Table 13.6. 1 Where standpipes are used, the head allowance required under
Section 1 3 . 1 . 1 0.2( 3) shall be not less than 1-1/2 inches.

e. Strainers shall not be required on open standpipes when used for secondary inlets.

f. Where secondary roof drainage is provided by roof drains or standpipes, they shall be permitted to
discharge horizontally, similar to scuppers, but below the roof level.

13.1.10.3 Vertical Walls

Where vertical walls drain onto roofs, an allowance based on 50% of the maximum projected wall area
shall be added to the roof area onto which each wall drains.

13.1.10.4 Equivalent Systems

When approved by the Authority Having Jurisdiction, the requirements of Sections 1 3. 1 . 1 0. 1 and
1 3.1 .10.2 shall not preclude the installation of an engineered roof drainage system that has sufficient
capacity to prevent water from ponding on the roof in excess of that allowed in the roof structural
design during a 1 00-year, 1 5-minute storm.

316 2006 National Standard Plumbing Cudc-lllustrated

13.1.11 Continuous Flow

Where continuous flow from a spring or ground water is encountered in a foundation drainage system or
other subsoil drain, the discharge shall be piped to a storm sewer or approved water course.

13.1.12 Backwater Valves

Where foundation drains, areaway drains, window well drains, or other storm water drains discharge by
gravity and are subject to backflow from their point of discharge, a backwater valve shall be provided in the
discharge line. Backwater valves shall comply with the requirements of Section 5.5.

13.2 MATERIALS

See Section 3.7. See Table 3.7 for approved materials for storm water drainage.

13.3 TRAPS IN STORM DRAINAGE SYSTEMS

13.3.1 General

a. Traps shall be installed in a storm drainage system if it connects to a combined sewer conveying both
sewage and storm water.

EXCEPTION: Traps shall not be required where roof drains, rain leaders, and other inlets are at locations
allowed under Section 12.4.4 for vent terminals.

b. Floor drains or other receptors within a building shall be individually trapped if they are connected to a
storm drainage system, regardless of whether or not the sewer is combined.

c. Traps required under this section shall comply with the requirements of Section 5.3.1, 5.3.2, 5.3.3, 5.3.5
and 13.3.2. Traps shall have accessible cleanouts or other means of clearing the trap.

Comment: Floor drains or other receptors that are connected to a storm drainage system or combined
sewer and are subject to evaporation of the trap seal must be provided with a deep seal trap or other
means of maintaining the trap seal. See Section 5.3. 6.

13.3.2 Location of Traps

Where traps are required under Section 13. 3.1. a, they shall be installed either on individual branches of the
storm drainage system or in the building storm drain or building storm sewer before it connects to the com-
bined sewer. Traps shall not be installed in locations where they will be subject to freezing. Where traps are
required for ram leaders, the minimum earth cover shall be as required in Section 2.16.b. See Figure 13.3.2

2006 Nutiamil Standard Plumbing Code- Illustrated 317

STORMWATER
CONDUCTORS

SOIL STACK

TRAP WITH CLEANOUTS

■ AT LEAST 10'
FROM SOIL STACK
(NOTE 1)

BUILDING STORM DRAIN

COMBINED BUILDING DRAIN

TO COMBINED BUILDING SEWER

NOTES:

1 . The trap is required when any of the storm water inlets are at locations where sanitary vent termi-
nals would not be permitted in Section 12.4.4. If all storm water inlets are at locations where
sanitary vent terminals would be permitted, the trap is not required. The storm water inlets will be
the same as vent terminals for the sanitary drainage system. Only those inlets in prohibited loca-
tions for sanitary vent terminals need to be trapped.

2. The connection between the building storm drain and the building sanitary drain needs to be a
horizontal wye "fitting that is at least 1 feet downstream from any soil stack.

Figure 13.3.2

A TRAP IN A STORM DRAINAGE SYSTEM

CONNECTED TO A COMBINED SEWER

13.3.3 Size of Traps

Traps shall be the same size as the drain pipe in which they are installed.

13,4 LEADERS OR CONDUCTORS AND CONNECTIONS

13.4.1 Not to be Used Improperly

Leaders or conductors shall not be used as soil waste, or vent pipes nor shall soil, waste, or vent pipes be
used as leaders.

1 3.4.2 Protection of Rain Water Leaders

Rain water leaders installed along alleyways, driveways, or other locations where they may be exposed to
damage shall be protected by metal guards, shall be recessed into the wall, or shall be constructed from
ferrous alloy pipe to a point 5 foot above grade. See Figure 13.4.2

Comment HI: The "JO feet downstream " requirement allows the sanitaty discharge to stabilize before
mixing with the storm water flow. It also reduces the backpressure on the sanitary drainage system that
may be caused by heavy storm water discharges.

Comment M2: The horizontal wye connection between the two drainage systems permits thejlows to mix
more uniformly without blocking the drain.

3J8

2006 National Standard Plumbing Cotle-IllustrawJ

LEADERS

PLASTIC OR
SHEET METAL
LEADER

GALVANIZED STEEL
OR CAST IRON
DOWNSPOUT BOOT

Figure 13.4.2
PROTECTION OF RAIN WATER LEADERS

•

13.4.3 Combining Storm with Sanitary Drainage

The sanitary and storm drainage system of a building shall be entirely separate, except that where a combined
sewer is used, the building storm drain shall be connected in the same horizontal plane through a single wye
fitting to the combined sewer at least 10 feet downstream from any soil stack.

13.4.4 Double Connections of Storm Drains

Where the sanitary and storm drains are connected on both sides of the combined sewer, single wyes shall
be used and the requirements of Section 13.4.3 relative to the location of connections shall also apply. See
Figure 1.2.15

Comment: Double pattern wye fittings are not permitted to connect sanitary drains and storm drains to a
combined drain. This is to prevent a heavy flow in one drain branch from causing a backpressure in the
other drain branch.

13.5 ROOF DRAINS

13.5.1 Compliance and Materials

Roof drains shall comply with ASME Al 12.6.4 and be constructed of coated or galvanized cast iron, bronze,
stainless steel, plastic, or other corrosion-resisting materials. Drains shall include any deck clamps or other
appurtenances necessary for installation and coordination with the roofing system.

13.5.2 Dome Strainers

Roof areas shall be drained to roof drains having raised dome strainers with dome free areas complying with
ASME A 1 1 2.6.4. The minimum free dome area shall be one and one-half ( 1 - 1/2) times the area of the drain outlet
connection.
EXCEPTIONS

( 1) Pitched roofs draining to hanging gutters.

(2) Roof areas subject to pedestrian and/or vehicular traffic.

2006 Noiioiuil Stan da ni Plumbing Code-Illustrated

319

13.5.3 Flat Grates

Roof drains on patios, sun decks, parking decks, and other areas subject to pedestrian and/or vehicular traffic shall
have flat grates with a free inlet area complying with ASME 1 1 2.6.4. The minimum grate free area shall be two
times the cross-sectional area of the drain outlet. Such drains shall not be located where they cannot be readily
inspected and maintained on a regular basis.

13.5.4 Roof Drain Flashings

The connection between roofs and roof drains that pass through the roof and into the interior of the building
shall be made watertight by the use of proper flashing material.

13.5.5 Roof Drain Restrictions

The roof drain size shall not be restricted by insertion of any roofing material or other objects to insure water
flow into the drain.

13.5.6 Roof Drain Outlet Pipe Size

The outlet pipe size of roof drains having vertical conductors shall be not less than the size required for
vertical conductors in Table 13.6.1.

13.6 SIZE OF LEADERS, GUTTERS AND STORM DRAIN PIPING

13.6.1 Vertical Conductors and Leaders

Vertical storm water conductors and leaders shall be sized according to Table 1 3.6. 1 . Where a vertical pipe
section is smaller than the preceding horizontal pipe section, the reduction in size shall be made in the vertical
pipe section.

13.6.2 Size of Horizontal Storm Drain Piping

Horizontal storm drain piping shall be sized according to Table 13.6.2. Such piping includes horizontal offsets
in storm water conductors, building drains, building sewers, and branches thereof. The size of the horizontal
drain piping shall not be reduced in the direction of flow.

13.6.3 Size of Roof Gutters

The size of semicircular roof gutters shall be based on the maximum projected roof area, according to Table
13.6.3.

13.7 RESERVED

13.8 SIZING FOR CONTINUOUS OR INTERMITTENT FLOWS

Continuous or intermittent flows from a sump pump, air conditioning condensate drain, or other approved discharge
into a storm drainage system shall be determined in gallons per minute flow. Air conditioning condensate drainage
shall be based on not less than 0.006 gpm/ton. Such flows shall be added to the stormwater load on the storm
drainage system, which shall also be determined on the basis of gallons per minute according to Table A.l and
Section A3 in Appendix A.

320 2006 National Simulant Plumbing Code-Illustrated

•

Table 13.6.1
SIZE OF VERTICAL CONDUCTORS AND LEADERS

Nominal
Diameter
(inches)

Flow

Capacity

(GPM)

Allowable Projected Roof Area
at Various Rates of Rainfall per Hoar (Sq. Ft.)

2,180

1,090

727

545

436

363

6,426

3,213

2,142

1,607

1,285

1,071

144

13,840

6,920

4,613

3,460

2,768

2,307

261

25,094

12,547

8,365

6,273

5,019

4,182

424

40,805

20,402

13,602

10,201

8,161

6,801

913

87,878

43,939

29,293

21,970

17,576

14,646

10"

1655

159,334

79,667

53,111

39,834

31,867

26,556

12"

2692

259,095

129,548

86,365

64,774

51,819

43,183

15"

4880

469,771

234,886

156,590

117,443

93,954

78,295

10"

11"

12"

311

272

242

218

198

182

918

803

714

643

584

536

144

1,977

1,730

1,538

1,384

1,258

1,153

261

3,585

3,137

2,788

2,509

2,281

2,091

424

5,829

5,101

4,534

4,080

3,710

3,400

913

12,554

10,985

9,764

8,788

7,989

7,323

10"

1655

22,762

19,917

17,704

15,933

14,485

13,277

12"

2692

37,014

32,387

28,788

25,910

23,554

21,591

15"

4880

67,110

58,721

52,197

46,977

42,706

39,146

NOTES:

1 . Flow capacities are based on stacks flowing 7/24 full.

2. Interpolation between rainfall rates is permitted.

13.9 CONTROLLED FLOW STORM WATER SYSTEM

13.9.1 Application

In lieu of sizing the storm drainage system on the basis of actual maximum projected roof areas as previously
described in this Chapter, the roof drainage system, or part thereof may be sized on equivalent or adjusted
maximum projected roof areas that result from controlled flow and storage of storm water on the roof pro-
vided flow control devices are used and subject to the approval of the Authority Having Jurisdiction.

13.9.2 Design

A controlled flow storm water system shall be designed, installed, inspected and certified as an engineered
special design plumbing system as outlined in Appendix E of this Code.

2006 Notional Standard Plumbing Code-f/fuxtmtcJ

321

Table 13.6.2 Part 1
SIZE OF HORIZONTAL STORM DRAINS (for 1 7hr to 67hr rainfall rates)

Size of

Drain

(inches)

Design Flow
of Drain
(GPM)

Allowable Projected Roof Area at Various
Rates of Rainfall per Hour (Square Feet)

17hr

27hr

37hr

47hr

57hr

67hr

Slope 1/16 inch/foot

5,101

2,551

1,700

1,275

1,020

850

9,336

4,668

3,112

2,334

1,867

1,556

157

15,111

7,556

5,037

3,778

3,022

2,519

339

32,629

16,314

10,876

8,157

6,526

5,438

615

59,194

29,597

19,731

14,798

11,839

9,866

999

96,154

48,077

32,051

24,039

19,231

16,026

1812

174,405

87,203

58,135

43,601

34,881

29,068

Size

GPM

1 7hr

27hr

37hr

47hr

57hr

6"/hr

Slope 1/8 inch/foot

3,369

1,684

1,123

842

674

561

7,219

3,609

2,406

1,805

1,444

1,203

137

13,186

6,593

4,395

3,297

2,637

2,198

223

21,464

10,732

7,155

5,366

4,293

3,577

479

46,104

23,052

15,368

11,526

9,221

7,684

869

83,641

41,821

27,880

20,910

16,728

13,940

1413

136,002

68,001

45,334

34,000

27,200

22,667

2563

246,689

123,345

82,230

61,672

49,338

41,115

Size

GPM

1 7hr

27hr

37hr

47hr

57hr

67hr

Slope 1/4 inch/foot

1,636

818

545

409

327

273

4,813

2,406

1,604

1,203

963

802

107

10,299

5,149

3,433

2,575

2,060

1,716

194

18,673

9,336

6,224

4,668

3,735

3,112

315

30,319

15,159

10,106

7,580

6,064

5,053

678

65,258

32,629

21,753

16,314

13,052

10,876

1229

118,292

59,146

39,431

29,573

23,658

19,715

1999

192,404

96,202

64,135

48,101

38,481

32,067

3625

348,907

174,454

116,302

87,227

69,781

58,151

Size

GPM

1 7hr

27hr

37hr

47hr

57hr

67hr

Slope 1/2 inch/foot

2,310

1,155

770

578

462

385

6,738

3,369

2,246

1,684

1,348

1,123

151

14,534

7,267

4,845

3,633

2,907

2,422

274

26,373

13,186

8,791

6,593

5,275

4,395

445

42,831

2 1 ,4 1 6

14,277

10,708

8,566

7,139

959

92,304

46,152

30,768

23,076

18,461

15,384

1738

167,283

83,641

55,761

41,821

33.457

27,880

2827

272,099

136,050

90,700

68,025

54,420

45,350

5126

493,379

246,689

164,460

123,345

98,676

82,230

322

2006 Nurional Sumdurd Plumbing Code-Illusrntrcd

NOTES:

1 . Design flows in Table 1 3.6.2 Part 1 are based on fairly rough pipe with a Manning friction coefficient "n" =
0.015.

2. The Authority Having Jurisdiction should be consulted forthe rainfall rate to be used for a particular location.

Table 13.6.2 Part 2
SIZEOFHORIZONTALSTORMDRAINS(for7"/hrto 127hr rainfall rates)

Size of Drain
finches)

Design Flow
of Drain

!
Allowable Projected Roof Area at Various Rates of Rainfall per Hour
(Square Feet of Roof)

Slope 1/16 inch/foot

Size

(GPM)

77hr

87hr

97hr

10"/hr

117hr

127hr

•

s - -,

729

638

567

510

464

425

1,334

1,167

1,037

934

849

778

157

2,159

1,889

1,679

1,511

1,374

1,259

339

4,661

4,079

3,625

3,263

2,966

2,719

615

8,456

7,399

6,577

5,919

5,381

4,933

999

13,736

12,019

10,684

9,615

8,741

8,013

1812

24,915

21,801

19,378

17,441

15,855

14,534

Slope 1/8 inch/foot

Size

GPM

7"/hr

87hr

97hr

107hr

llThr

127hr

481

421

374

337

306

281

1,031

902

802

722

656

602

223

3,066

2,683

2,385

2,146

1,951

1,789

479

6,586

5,763

5,123

4,610

4,191

3,842

869

1 ! ,494

10,455

9,293

8,364

7,604

6,970

1413

12,429

17,000

15,111

13,600

12,364

11,334

2563

35,241

30,836

27,410

24,669

22,426

20,557

Slope 1/4 inch/foot

Size

GPM

77hr

8'7hr

9"/hr

107hr

1 1 Thr

127hr

234

205

182

164

149

136

688

602

535

481

438

401

107

1,471

1,287

1 j J t f*T

1,030

936

858

194

2,668

2,334

2,075

1,867

1,698

1,556

315

4,331

3,790

3,369

3,032

2,756

2,527

678

9,323

8,157

7,251

6,526

5,933

5,438

1229

16,899

14,787

13,144

11,829

10,754

9,858

1999

27,486

24,051

21,378

19,240

17,491

16,034

3625

49,844

43,613

38,767

34,891

31,719

29,076

•

2006 National Standard Plumbing Code-Mummied

323

Table 13.6.2 Part 2 (continued)

SIZEOFHORIZONTALSTORMDRAINS(for7"/hrtol2"/hrrainfallrates)

Slope 1/2 inch/foot

Size

GPM

7"/hr

8"/hr

97hr

107hr

ll'Vhr

127hr

330

289

257

231

210

193

963

842

749

674

613

562

151

2,076

1,817

1,615

1,453

1,321

1,211

274

3,768

3,297

2,930

2,637

2,398

2,198

445

6,119

5,354

4,759

4,283

3,894

3,569

959

13,186

11,538

10,256

9,230

8,391

7,692

1738

23,898

20,910

18,587

16,728

15,208

13,940

2827

38,871

34,012

30,233

27,210

24,736

22,675

5126

70,483

61,672

54,820

49,338

44,835

41,115

NOTES:

1. Design flows in Table 13.6.2 Part 1 are based on fairly rough pipe with a Manning friction coefficient
"n" = 0.015.

2. The Authority Having Jurisdiction should be consulted for the rainfall rate to be used for a particular location.

Table 13.6.3
SIZE OF ROOF GUTTERS'

Diameter of
Gutter 2
I nchcs

Maximum

Pre

jeeted

Roof Area

for Gutters

Vi6

in Slope 3

Sq. Ft.

GPM

170

360

625

960

1.380

1.990

3.600

150

Table 1 3.6.3 is based upon a maximum rate of rainfall of 4 inches per hour. Where
maximum rates are more or less than 4 inches per hour, the figures for drainage area shall
be adjusted by multiplying by 4 and dividing by the local rate in inches per hour. See
Appendix A.

Gutters other than semicircular may be used provided they have an equivalent cross-
sectional area.

Capacities given for slope of 1/16 inch per foot shall be used when designing for greater
slopes.

324

2006 Natiomil Standard Plamhinv Code-Jllustraleil

Chapter 14

Special Requirements For Health Care Facilities

14.1 GENERAL

This Chapter applies to special fixtures and systems that occur in health care facilities and to the special plumbing
requirements in such facilities. Ordinary plumbing in such facilities shall comply with the other applicable Chapters
of this Code.

14.2 WATER SERVICE

Where required by the Authority Having Jurisdiction, hospitals and similar health care facilities shall have dual
water service lines to maintain a water supply in the event of a water main failure. Where possible, the service
pipelines shall be connected to different water mains so that a single water main break can be isolated and re-
paired without shutting off all water service to the facility.

14.3 MEDICAL GAS AND VACUUM PIPING SYSTEMS

14.3.1 Genera]

The installation of medical gas and vacuum piping systems shall be in accordance with the requirements of
either NFPA 99 - Standard for Health Care Facilities or NFPA 99C - Gas and Vacuum Systems.

1 4.3.2 Professional Qualifications of Installers, I nspectors and Verifiers

Installers (including brazers), inspectors, and verifiers of medical gas and vacuum systems shall meet the
requirements of ANSI/ASSE Series 6000 - Professional Qualification Standard for Medical Gas Systems
Installers, Inspectors, and Verifiers, or the equivalent.

14.4 PROTRUSIONS FROM WALLS

Drinking fountains, control valves, medical gas station outlets, vacuum inlet stations, risers, cleanout covers, and
other devices shall be fully-recessed in corridors and other areas where patients may be transported on a gumey,
hospital bed, or wheelchair. Protective guards shall be provided where necessary.

14.5 MENTAL PATIENT ROOMS

Piping and drain traps in mental patient rooms shall be concealed. Fixtures and fittings shall be vandal-proof.

Comment: Plumbing that is accessible to mental patients must be suicide-proof, vandal-proof, and
sound-proof Piping is installed in chases that are not accessible to the patients. Special Jixtu res, such
as combination lavatory/toilets, are available for such applications. The fixtures are pushbutton
operated to avoid faucet handles. Most fixtures are constructed of stainless steel. The plumbing fixtures
used in mental facilities are similar to those used in correctional institutions.

2006 Naiiuiml Standard Phimtvng Code-Hlustnved

325

14.6 PROHIBITED LOCATIONS FOR ICE STORAGE

Ice makers or ice storage chests shall not be located in a Soiled Utility Room or similar areas where subject to
possible contamination.

14.7 CROSS CONNECTION CONTROL AND BACKFLOW PREVENTION

a. Backflow prevention shall be in accordance with Section 10.5.

b. Vacuum breakers for bedpan washers shall be not less than 5 feet above the floor.

14.8 CLINICAL SINKS AND BEDPAN WASHERS

14.8.1 General

a. Clinical sinks and bedpan washers, and flushing-rim service sinks shall be installed in the same manner
as water closets. Where such fixtures have a vent connection on the inlet side of their trap, a local vent shall
be provided in accordance with Section 14.9.

b. Clinical sinks shall not be used as a substitute for non-flushing service sink, nor shall a non-flushing
service sink be utilized to clean bedpans.

c. Vacuum breakers for bedpan washers shall be installed in accordance with Section 14.7.b.
See Figure 14.8

•

326 2006 Nutioruil Standard Plumbing Code-Illustrated

VACUUM BREAKER

MIXING VALVE

FLUSH VALVE

WATER CLOSET

- WALL HUNG
BEDPAN WASHER

■ HAND SPRAY WITH
VOLUME CONTROL

WALL CONTROL TYPE

SINK FAUCET

FLUSH VALVE

WATER CLOSET OR ■
SERVICE SINK WITH
FLUSHING RIM
(CLINICAL SINK)

VACUUM BREAKER

HOSE AND
SPRAY NOZZLE

FOOT VALVE
CONTROL

FLUSH VALVE

■ DIVERTER
ASSEMBLY

WATER CLOSET OR
SERVICE SINK WITH
FLUSHING RIM
{CLINICAL SINK)

FOOT CONTROL TYPE

DIVERTER TYPE

NOTES:

1 . The divertor type of bedpan washer is typically installed in a patient toilet room. When the divertor
is fully raised, the flush valve supplies the water closet bowl in the normal manner. When the
divertor is lowered, the flush valve supplies the divertor to rinse the bedpan. After the bedpan has
been rinsed into the water closet, the divertor can be raised and the water closet flushed. The
elevation of the flush valve vacuum breaker above the overflow rim level of the water closet should be
as recommended by the manufacturer.

2. The wall control type of bedpan washer is typically installed in a patient toilet room. The bedpan is
rinsed into the water closet bowl using the hand spray from the wall control unit. The water closet is
then flushed using the flush valve. Section 14. 7. b requires that the vacuum breaker in the wall
control unit be at least 5 feet above the floor to prevent a cross connection.

3. The foot control type of bedpan washer is typically installed in a soiled utility room with a clinical
sink. The bedpan is rinsed into the water closet bowl using the hand spray and foot control valve.
The clinical sink is then flushed using the flush valve. Section 1 4.7.b requires that the vacuum
breaker for the hose spray be at least 5 feet above the floor to prevent a cross connection. The sink
faucet allows the clinical sink to be used as a service sink for housekeeping purposes.

Figure 14.8
TYPES OF BEDPAN WASHERS

2006 National Standard Plumbing Codt'-lllusrraitd

327

14.9 LOCAL VENTS AND STACKS FOR CLINICAL SINKS
OR BEDPAN WASHERS

14.9.1 General

Where clinical sinks or bedpan washers have provisions for a local vent, a local vent shall be extended to the
outdoors above the roof. Local vents shall terminate in accordance with Section 12.4. Local vents from
clinical sinks or bedpan washers shall not be connected to vapor vents for sterilizers or to any drainage
system vent.

14.9.2 Material

Local vent piping shall be of a material acceptable for sanitary vents in accordance with Section 3.6.

1 4.9.3 Required Size and Arrangement

A local vent serving a single clinical sink or bedpan washer shall be not less than 2" pipe size. Where such
fixtures are installed back-to-back or are located above each other on more than one floor, a local vent stack
may be provided to serve multiple fixtures. A 2" local vent stack may serve up to three fixtures. A 3" local
vent stack may serve up to six fixtures. A 4" local vent stack may serve up to twelve fixtures. In multiple
installations, the connections to the local vent stack shall be made using sanitary tee or tee-wye fittings
oriented for upward flow from the branch. A branch connection to a local vent stack shall extend not more
than 5 feet horizontally and shall be sloped not less than 1/4 inch per foot back towards the fixture served.

14.9.4 Provisions for Drainage

Provisions shall be made for the drainage of vapor condensation within local vent piping. A local vent serving
a single fixture may drain back to the fixture served. The base of a local vent stack serving one or more
fixtures shall be directly connected to a trapped and vented waste branch of the sanitary drainage system.
The trap and waste branch shall be the same size as the local vent stack. The trap seal depth shall be not less
than 3 inches. The vent for the waste branch shall be 1-1/4" minimum size, but not less than one-half the size
of the waste branch.

14.9.5 Trap Priming

The waste trap required under Section 14.9.4 shall be primed by at least one clinical sink or bedpan washer
on each floor served by the local vent stack. A priming line not less than J/4" OD size shall be extended from
the discharge or fixture-side of the vacuum breaker protecting the fixture water supply to the local vent stack.
A trap having not less than a 3-inch water seal shall be provided in the priming line. The line shall prime the
trap at the base of the local vent stack each time that a fixture is flushed.

14.10 STERILIZERS

14.10.1 General

The requirements of this Section apply to sterilizers and bedpan steamers. Such equipment shall be installed in
accordance with this Code and the manufacturer's instructions.

14.10.2 Indirect Waste Connections

All waste drainage from sterilizers and bedpan steamers shall be indirectly connected to the sanitary drainage
system through an air gap, in accordance with Chapter 9. Indirect waste pipes shall be not less than the size
of the dram connection on the fixture. Separate waste pipes shall be provided for each fixture, except that up

328 2006 National Standard Plumbing Code-Illustrated

to three sterilizers may have a common indirect waste pipe if its developed length does not exceed 8 feet. The
size of such common indirect waste pipes shall be not less than the aggregate cross-sectional area of the
individual sterilizer drain connections. Except for bedpan steamers, indirect waste pipes shall not require traps.

14.10.3 Floor Drains

a. A trapped and vented floor drain, not less than 3" pipe size, shall be provided in each recess room or
space where recessed or concealed portions of sterilizers are located. The floor drain shall drain the entire
floor area and shall receive the indirect waste from at least one sterilizer. Where an air gap fitting is provided,
the waste pipe from the fitting may connect to the body of the floor drain above its trap seal.

b. Where required by the sterilizer manufacturer, a floor drain shall be located directly beneath the steril-
izer within the area of its base.

14.10.4 Cooling Required

Waste drainage from condensers or steam traps shall be cooled below 140°F before being discharged indi-
rectly to the sanitary drainage system.

14.10.5 Traps Required for Bedpan Steamers

A trap having a minimum seal of 3 inches shall be provided in the indirect waste pipe for a bedpan steamer,
located between the fixture and the air gap at the indirect waste receptor.

14.11 VAPOR VENTS AND STACKS FOR STERILIZERS

14.11.1 General

Where sterilizers have provisions for a vapor vent and such a vent is required by their manufacturer, a vapor
vent shall be extended to the outdoors above the roof. Sterilizer vapor vents shall terminate in accordance
with Section 1 2.4 and shall not be connected to local vents for clinical sinks or bedpan washers or to any
drainage system vent.

14.11.2 Material

Sterilizer vapor vent piping shall be of a material acceptable for sanitary vents in accordance with Section 3.6.

14.1 1 .3 Required Size and Arrangement

a. Sterilizer vapor vents and stacks for individual sterilizers shall be not less than the size of the sterilizer
vent connection, except that stacks shall be not less than 1-1/2" pipe size. Where vapor vent stacks serve
more than one sterilizer, the cross-sectional area of the stack shall be not less than the aggregate cross-
sectional areas of the vapor vents for all of the sterilizers served.

b. In single and multiple installations, the connections to the vapor vent stack shall be made using sanitary
tee or tee-wye fittings oriented for upward flow from the branch. A branch connection to a sterilizer vapor
vent stack shall extend not more than 5 feet horizontally and shall be sloped not less than 1/4 inch per foot
away from the sterilizer and toward the vent stack.

14.11.4 Provisions for Drainage

Provisions shall be made for the drainage of vapor condensation within sterilizer vapor vent piping. The base
of stacks shall drain indirectly through an air gap to a trapped and vented waste receptor connected to the
sanitary drainage system.

2006 Nutioiuil Standard Plumbing Code-Illustrated 329

14.12 DRAINAGE FROM CENTRAL VACUUM SYSTEMS

14.12.1 General

Provisions for drainage from medical, surgical, dental, and similar central vacuum systems shall be as required
by either NFPA 99 - Health Care Facilities or NFPA 99C - Gas and Vacuum Systems. In addition, drainage
from dental and other vacuum systems that collect fluid waste centrally shall comply with Sections 14. 12.2
through 14. 12.4.

14.12.2 Positive Pressure Drainage from Air/Waste Separators in Dental Vacuum Systems

a. The waste outlet from an air/waste separator on the discharge side of a vacuum pump or blower shall be
direct-connected to the sanitary drainage system through a deep-seal trap that is conventionally vented within the
plumbing system. The trap vent shall extend vertically to not less than 6 inches above the top of the separator
before making any horizontal turns. The vacuum exhaust air flow from the separator shall be separately vented
to outodoors as required under NFPA 99 and NFPA 99C.

b. The trap and drain branch size shall be at least two pipe sizes larger than the waste pipe from the separator,
but not less than 1 - 172" pipe size. The vent shall be the full size of the trap and drain. The trap seal shall be at least
two times the exhaust backpressure in the separator, but not less than 4 inches deep.

14.12.3 Gravity Drainage from Waste Holding Tanks in Dental Vacuum Systems

a. The drainage from waste holding tanks shall extend from the vacuum check valve on the waste outlet
of the tank and be direct-connected to the sanitary drainage system through a deep-seal trap that is conven-
tionally vented within the plumbing system. Jn addition, a vent shall be installed between the vacuum check
valve and the drain trap, on the inlet side of the trap, to seal the check valve when the holding tank is operat-
ing under vacuum and collecting waste. This vent shall be connected to the plumbing system vents. Both
vents shall extend vertically to not less than 6 inches above the top of the holding tank before making any
horizontal turns.

b. The trap and drain size shall be at least two pipe sizes larger than the waste outlet and vacuum check valve,
but not less than 2" pipe size. The trap shall be not less than 4 inches deep. The vent for the vacuum check valve
shall be not less than the size of the check valve. The trap vent shall be not less than one-half the size of the trap
and drain branch.

14.12.4 Protection from Sewage Backup in Dental Vacuum Systems

A floor drain or other trapped and vented receptor shall be provided near the connection of the drain from a dental
vacuum air/waste separator or waste holding tank to the sanitary drainage system that will overflow in the event
of a backup in the sanitary drainage system and prevent the backup from reaching the level of the trap for the
air /waste separator or the drain check valve for the waste holding tank. The trap of the floor drain or receptor
shall be primed if it does not receive an indirect waste discharge.

14.13 ASPIRATORS

Provisions for aspirators or other water-supplied suction devices shall be installed only with the specific approval of
the Authority Having Jurisdiction. Where aspirators are used for removing body fluids, they shall include a collec-
tion bottle or similar fluid trap. Aspirators shall indirectly discharge to the sanitary drainage system through an air
gap. in accordance with Chapter 9. The potable water supply to an aspirator shall be protected by a vacuum
breaker or equivalent, in accordance with Sections 14.7 and 10.5.3.

330 200b National Standard Pliimbini; Code-lllusirnteJ

Chapter 15

Tests and Maintenance

15.1 EXPOSURE OF WORK

New, altered, extended or replaced plumbing shall be left uncovered and unconcealed until it has been tested and
approved. Where such work has been covered or concealed before it is tested and approved, it shall be exposed
for testing.

15.2 EQUIPMENT, MATERIAL AND LABOR FOR TESTS

Equipment, material and labor required for testing a plumbing system or part thereof shall be furnished by the
installing contractor.

15.3 TESTING OF PLUMBING SYSTEMS

•

15.3.1 General

New plumbing systems and parts of existing systems that have been altered, extended or repaired shall be
tested as prescribed hereinafter to disclose leaks and defects only when required by the Authority Having
Jurisdiction.

15.3.2 Exceptions

a. When required by the Authority Having Jurisdiction, where an existing concealed sewer or drain is reused
as part of a new or renovated drainage system, the line shall be traced to its point of termination and shall be
tested to determine that:

1. it is connected to the proper drainage system, such as sanitary or storm,

2. It will withstand a leak test, and,

3. It is free-flowing and not restricted.

15.4 METHODS OF TESTING THE DRAINAGE AND VENT SYSTEMS

15.4.1 Rough Plumbing

a. Except for outside leaders and perforated or open jointed drain tile, the piping of plumbing drainage and
venting systems shall be tested upon completion of the rough piping installation by water or air and proved
watertight. The Authority Having Jurisdiction may require the removal of any cleanout plugs to ascertain if
the pressure has reached all parts of the system. Either of the following test methods shall be used.

1 . The water test shall be applied to the drainage system either in its entirety or in sections after rough
piping has been installed. If applied to the entire system, all openings in the piping shall be tightly closed,
except the highest opening, and the system filled with water to point of overflow. If the system is tested in

2006 National Standard Plumbing Code.-lllitstrattd

331

sections, each opening shall be tightly plugged except the highest opening of the section under test, and each
section shall be filled with water, but no section shall be tested with less than a 10-foot head of water. In
testing successive sections at least the upper 10 feet of the next preceding section shall be tested, so that no
joint or pipe in the building (except the uppermost 10 feet of the system) shall have been submitted to a test of
less than 10-foot head of water. The water shall be kept in the system or in the portion under test for at least
15 minutes before inspection starts; the system shall then be tight at all points.

2. The air test shall be made by attaching an air compressor testing apparatus to any suitable opening and
after closing all other inlets and outlets to the system, forcing air into the system until there is a uniform gauge
pressure of 5 pounds per square inch or sufficient to balance a column of mercury 10 inches in height. This
pressure shall be held without introduction of additional air for a period of at least 1 5 minutes.

15.4.2 Finished Plumbing

a. When the rough plumbing has been tested in accordance with section 1 5 .4. 1 , a final test of the finished
plumbing system may be required to insure that the final fixture connections to the drainage system are gas-
tight.

b. After the plumbing fixtures have been set and their traps- filled with water, their connections shall be
tested and proved gas and watertight. A final smoke or peppermint test shall be required, except in the case
of a previous on site-inspected water or air tested system. If a smoke or peppermint test is required, the
following test methods shall be employed:

1 . A smoke test shall be made by filling all traps with water and then reintroducing into the entire system a
pungent, thick smoke produced by one or more smoke machines. When the smoke appears at stack openings
on the roof, they shall be closed and a pressure equivalent to a one-inch water column shall be developed and
maintained for the period of the inspection.

2. Where the Authority Having Jurisdiction, due to practical difficulties or hardships, finds that a smoke
test cannot be performed, a peppermint test shall be substituted in lieu thereof. Such peppermint test shall be
conducted by the introduction of two ounces of oil of peppermint into the roof terminal of every line or stack
to be tested. The oil of peppermint shall be followed at once by ten quarts of hot (HOT) water whereupon all
roof vent terminals shall be sealed. A positive test, which reveals leakage, shall be the detection of the odor of
peppermint at any trap or other point on the system. Oil of peppermint or persons whose person or clothes
have come in contact with oil of peppermint shall be excluded from the test area.

Comment: The smoke or peppermint tests on the finished plumbing can he waived by the Authority
Having Jurisdiction when they are considered to be unnecessary. However, the finished plumbing tests
should be performed if the installation appears to be improper or there is the odor of sewer gas.

15.5 METHOD OF TESTING BUILDING SEWERS

The building sewer shall be tested by insertion of a test plug at the point of connection with the public sewer,
private sewer, individual sewer disposal, or other point of disposal. It shall then be filled with water under a head of
not less than 10 feet. The water level at the top of the test head of water shall not drop for at least 15 minutes.
Where the final connection of the building sewer cannot reasonably be subjected to a hydrostatic test, it shall be
visually inspected.

332 2006 National Standard Plumbing Code-IllusireucJ

•

15.6 METHODS OF TESTING WATER SUPPLY SYSTEMS

a. Upon completion of a section or the entire water supply system, it shall be tested and proved tight under a
water pressure not less than the working pressure under which it is to be used or 80 pounds per square inch,
whichever is greater.

b. For metallic pipe and where the Authority Having Jurisdiction determines that providing potable water for the
test represents a hardship or practical difficulty, the system may be tested with air to the pressures noted above, as
allowed by the pipe manufacturer.

c. For plastic pipe, testing by compressed gas or air pressure shall be prohibited.

d. Piping shall be disinfected after testing per Section 10.9.

15.7 DEFECTIVE PLUMBING

Where there is reason to believe that the plumbing system of any building has become defective, it shall be sub-
jected to test or inspection and any defects found shall be corrected.

15.8 MAINTENANCE

15.8.1 General

The plumbing and drainage systems shall be maintained at all times in compliance with the provisions of this
Code.

15.8.2 Exception

Existing plumbing installed under prior regulations or lack thereof, may remain unchanged unless immediate
hazards to health, life, or property are evident.

2006 National Standard Plumbing Cude-1/tusrrawd 333

Blank Page

334 2006 National Standard Plumbing Code-lHustrated

Chapter 16

Regulations Governing Individual Sewage Disposal

Systems for Homes and Other Establishments Where

Public Sewage Systems Are Not Available

16.1 GENERAL PROVISIONS

16.1.1 General

In the absence of State or other local laws governing the installation, use and maintenance of private sewer
disposal systems, the provisions of this Chapter shall apply.

16.1.2 Sewage Disposal

"Sewage disposal" under this section shall mean all private methods of collecting and disposing of domestic
sewage, including septic tanks.

16.1.3 Domestic Sewage

Domestic sewage shall be disposed of by an approved method of collection, treatment and effluent discharge.
Domestic sewage or sewage effluent shall not be disposed of in any manner that will cause pollution of the
ground surface, ground water, bathing areas, lakes, ponds, watercourses, tidewater, or create a nuisance. It
shall not be discharged into any abandoned or unused well, or into any crevice, sink hole, or other opening
either natural or artificial in a rock formation.

Comment: Federal and local environmental agencies have criteria for the allowable contaminant levels
that can he discharged into a water course or other point of discharge. Improper disposal of sewage can
result in; (1) contamination of public or private water supplies, (2) spread of disease by insects or vermin,
(3) creation of objectionable odors, (4) pollution of public water resources, or (5) other conditions that
are detrimental to public health and safety.

1 6. 1 .4 Non-Water-Carried Sewage

When water under pressure is not available, all human body wastes shall be disposed of by depositing them in
approved privies, chemical toilets, or such other installations acceptable to the Authority Having Jurisdiction.

16.1.5 Water-Carried Sewage

Water-carried sewage from bathrooms, kitchens, laundry fixtures and other household plumbing shall pass
through a septic or other approved sedimentation tank prior to its discharge into the soil or into a sand filter.
Where underground disposal or sand filtration is not feasible, consideration shall be given to special methods
ofcollection and disposal.

2006 National Standard Plumbing Code-IUiisnoicd

335

16.1.6 Responsibility

The installing contractor is responsible for compliance with these regulations.

16.1.7 Abandoned Disposal Systems

Abandoned disposal systems shall be disconnected from the buildings, pumped out and filled with earth.

Comment: This requirement applies to all abandoned dry wells, septic tanks, cesspools, distribution
boxes, seepage pits, and other structures that have handled sewage or sewage by-products.

16.1.8 Absorption Capacity

No property shall be improved in excess of its capacity to properly absorb sewage effluent in the quantities
and by means provided for in this Code. (See Section 2.19.2.) See Sections 16.5 and 16.6

Comment: The development of properties must be limited by the ability of the soil to absorb the effluent
of the required sewage disposal system. Bacterial action within the soil provides secondary treatment of
the effluent from septic tanks.

16.1.9 Reserved

16.1.10 Higher Compliance

Nothing contained in this Chapter shall be construed to prevent the Authority Having Jurisdiction from requir-
ing compliance with higher requirements than those contained herein where such higher requirements are
essential to maintain a safe and sanitary condition.

16.2 RESERVED

16.3 DESIGN OF INDIVIDUAL SEWAGE SYSTEM

16.3.1 Design

The design of the individual sewage disposal system must take into consideration location with respect to
wells or other sources of water supply, topography, water table, soil characteristics, area available, and
maximum occupancy of the building. See Sections 16.4 through 16.12

Comment #1: The primary factors in the design of private sewage disposal systems are; (1) the location
of the disposal system, (2) the absorption capacity of the soil, (3) the size of the drainage field, (4) the
size of the septic tank, (5) the elevation of the ground water table, (6) the location of water supplies for
the propaiy and neighboring properties, (7) the use and population of the building(s) served, (8) the
topography of the property.

Comment #2: Problems with topography (elevation differences) can be overcome by sewage pumps,
which can pump to elements of the disposal system that are at higher elevations than others.

336

20U6 Nuriomil Standard Plumbing Corfe-lllusiraieJ.

•

16.3.2 Type of System

The type of system to be installed shall be determined on the basis of location, soil permeability, and ground-
water elevation. See Sections 16.4 and 16.5.

16.3.3 Sanitary Sewage

The system shall be designed to receive all sanitary sewage, including laundry waste, from the building.
Drainage from footings or roofs shall not enter the system.

Comment: Storm water and foundation drains must not be connected to a private sewage disposal
system.

16.3.4 Discharge

The system shall consist of a septic tank discharging into either a subsurface disposal field or one or more
seepage pits or into a combination of both, if found adequate as such and approved by the Authority Having
Jurisdiction. See Figure 1.2.45 and the definitions of "Septic Tank" and "Leaching Well or Pit".

16.3.5 Backflow

Plumbing fixtures connected to a private sewage disposal system that are subject to backflow, shall be
protected by a backwater valve or a sewage ejector.

Comment: Where plumbing fixtures connected to a private sewage disposal system are subject to
backflow from a blockage in the disposal system, they must be protected by a backwater valve. Sewage
pumps and ejectors having check valves provide this protection for the fixtures that they serve.

16.3.6 Reserved

16.3.7 Design Criteria

Design criteria for sewage flows shall be selected according to type of establishment. (See Table 16.3.7.)

2006 National Standard Plttnibiiiz Cude-lllustrated 337

Table 163.7
SEWAGE FLOWS ACCORDING TO TYPE OF ESTABLISHMENT

Type of Establishment

Schools (toilets and lavatories only) 15 Gal. per day per person

Schools (with above plus cafeteria) 25 Gal. per day per person

Schools (with above plus cafeteria and showers) 35 Gal. per day per person

Day workers at schools and offices 15 Gal. per day per person

Day camps 25 Gal. per day per person

Trailer parks or tourist camps (with built-in bath) 50 Gal. per day per person

Trailer parks or tourist camps (with central bathhouse) 35 Gal. per day per person

Work or construction camps 50 Gal. per day per person

Public picnic parks (toilet wastes only) 5 Gal. per day per person

Public picnic parks (bathhouse, showers and flush toilets) 10 Gal. per day per person

Swimming pools and beaches 10 Gal. per day per person

Country clubs , 25 Gal. per day per person

Luxury residences and estates 150 Gal. per day per person

Rooming houses 40 Gal. per day per person

Boarding schools 50 gal. per day per person

Hotels (with connecting baths) 50 Gal. per day per person

Hotels (with private baths-2 persons per room 100 Gal. per day per person

Boarding schools 100 Gal. per day per person

Factories (gallons per person per shift-exclusive of

industrial waste) 25 Gal. per day per person

Nursinghomes 75 Gal. per day per person

General hospitals 150 Gal. per day per person

Public Institutions (other than hospitals) 100 Gal. per day per person

Restaurants (toilet and kitchen wastes per unit of

serving capacity) 25 Gal. per day per person

Kitchen wastes from hotels, camps, boarding houses, etc.

serving three meals per day 10 Gal. per day per person

Motels 50 Gal. per bed space

Motels with bath, toilet, and kitchen wastes 60 Gal. per bed space

Drive-in theatres 5 Gal. per car space

Stores 400 Gal. per toilet room

Service stations 10 Gal. per vehicle served

Airports 3-5 Gal. per passenger

Assembly halls 2 Gal. per seat

Bowling alleys 75 Gal. per lane

Churches (small) 3-5 Gal. per sanctuary seat

Churches (large with kitchen) 5-7 Gal. per sanctuary seat

Dance halls 2 Gal. per day per person

Laundries (coin operated) 400 Gal. per machine

Service stations 1000 Gal. (First Bay)

500 Gal. (Each add. Bay)

Sub-divisions or individual homes 75 Gal. per day per person

Marinas-Flush toilets 36 Gal. per fixture per hr

Urinals , 10: Gal. per fixture per hr

Wash basins 15 Gal. per fixture per hr

Showers 150 Gal. per fixture per hr

338 2006 National Standard Plumbing Code-Illustrated

16.4 LOCATION OF INDIVIDUAL SEWAGE SYSTEM

16.4.1 Reserved

16.4.2 Reserved

16.4.3 Minimum Distances

The minimum distances that shall be observed in locating the various components of the disposal system shall
be as given in Table 1 6.4.3.

Table 16.4.3

MINIMUM DISTANCE BETWEEN COMPONENTS

OF AN INDIVIDUAL SEWAGE DISPOSAL SYSTEM (in feet) ]

Shallow
Well

Deep
Well

Single

Suction

Line

Septic
Tank

Distribution
Box

Disposal
Field

Seepage
Pit

Dry

Well

Property
Line

Building'

Bldg. Sewer
other than
cast-iron

Bldg. Sewer
cast-iron

Septic Tank

100

10 1

Distribution
Box

100

Disposal
Field

100

Seepage
Pit

100

Dry Well

100

Shallow
Well

100

Deep
Well

Suction
Line

'May be closer to building when permission is given by the Authority Having Jurisdiction

16.4.4 General

All sewage disposal systems shall conform with the following general principles regarding site:

16.4.4.1 Location

Sewage disposal system shall be located at the lowest point on the premises consistent with the general
layout topography and surroundings, including abutting lots. Locations at a higher elevation through
employment of a forced system may be used with the specific approval of the Authority Having
Jurisdiction.

16.4.4.2 Watersheds

Sewage disposal facilities shall not be located on any watershed for a public water supply system.

1 6.4.4.3 Septic Tanks and U nderground Disposal

Septic tanks and underground disposal means shall not be within 200 feet measured horizontally from

2006 National Standard Plumbing. Code-Illustrated

339

the high water level in a reservoir or the banks of tributary streams when situated less than 3,000 feet
upstream from an intake structure.

16.4.4.4 Beyond 3,000 feet

Sewage disposal facilities situated beyond 3,000 feet upstream from intake structures shall be located
no less than 100 feet measured horizontally from the high water level in the reservoir or the banks of
tributary streams.

16.4.4.5 Percolation Test

Prior to approval, the soil must prove satisfactory by the standard percolation test when underground
disposal is used. See Section 16.5

16.5 PERCOLATION TEST

Percolation tests to determine the absorption capacity of soil for septic tank effluent shall be conducted in the
following manner:

16.5.1 Subsurface Irrigation

When subsurface irrigation is contemplated, a test pit shall be prepared 2 feet square and not less than 1 foot
deep. At the time of conducting the percolation test, a hole 1 foot square and 1 foot deep shall be prepared in
the test pit.

16.5.2 Water Depth

The hole shall be filled with water to a depth of 7 inches. For pre-wettmg purposes, the water level shall be
allowed to drop 6 inches before time of recording is started.

16.5.3 Time Expired

The time required for the water level to drop 1 inch from 6 inches to 5 inches in depth shall be noted and the
length of tile in the subsurface irrigation system shall be obtained from Section 16.5.4. In no case, however,
shall less than 100 feet of tile be installed when 1 foot trenches are used.

16.5.4 Tile Length

The tile lengths, in feet, for each 100 gallons of sewage per day are as follows:

Time in Minutes Trench Width

for 1-inch Drop I -foot 2-feet 3-feet

1 25 13 9

2 30 15 10

3 35 18 12
5 42 21 14

10 59 30 20

15 74 37 25

20 91 46 31

25 105 53 35

30 125 63 42

Comment: Determine the total daily sewage flow for the system from Table 16.3. 7. Divide this number
by J 00 and determine the required length and number of tiles in the underground disposal system.

340 2006 Nutionul Standard Plumbing Code-lllustraied

16.5.5 Seepage Pits

When seepage pits are contemplated, test pits approximately 5 feet in diameter to permit a man entering the
pit by means of a ladder and to such depth as to reach a porous soil shall be prepared. In the bottom of this
pit, a 1 foot square by 1 foot deep hole shall be made at the time of testing and the percolation test conducted
as indicated under Sections 16.5.1, 16.5.2, and 16.5.3. See the definition of "Leaching Well or Pit" and
Figure 1.2.41.

Comment: Observe safety requirements regarding sheeting, shoring, and bracing for deep excavations.

1 6.5.6 Seepage Pit Absorption Area

The absorption area of a seepage pit required shall be obtained from Table 16.5.6. In no case, however, shall
the absorption area in the porous soil be less than 1 25 square feet. The bottom of the pit shall not be consid-
ered part of the absorption area.

Comment: The absorption area of a seepage or leaching pit is the square foot area of the sidewalls. The
sidewall area = 3.1416 x diameter x depth (both in feet).

Table 16.5.6
REQUIRED ABSORPTION AREA IN SEEPAGE PITS FOR EACH 1 00 GALLONS OF

SEWAGE PER DAY

Time in Minutes Effective Absorption Area

1 for 1-inch Drop Square Feet

1 32

2 40

3 45
5 56

10 75

15 96

20 108

25 139

30 167

16.5.7 Thickness of Porous Soil

The thickness of the porous soil below the point of percolation test must be determined by means of digging a
pit or using a soil auger. The effective absorption area shall be calculated only within this porous soil.

16.6 CAPACITY OF SEPTIC TANKS

16.6.1 Liquid Capacity

The liquid capacity of all septic tanks shall conform to Tables 16.3.7 and 16.6.1 as determined by the number
of bedrooms or apartment units in dwelling occupancies and the occupant load or the number of plumbing
fixture units as determined from Table 1 1.4.1. (whichever is greater) in other building occupancies.

Comment: The septic tank sizes in Table 16.6.1 have allowances for sludge storage space and the use of
domestic food waste disposal units.

2006 National Standard Plumbitt" Code-Ilhi.stnued 341

Table 16.6.1

CAPACITY OF SEPTIC TANKS

Multiple

Other uses;

Minimum

Single family

dwellings units or

maximum

septic tank

dwelling-number

apartments-one

fixture

capacity in

of bedrooms

bedroom each

units served

gallons

1-3

1000

2 units

1200

5 or 6

1500

7 or 8

2000

2250

2500

2750

3000

3250

100

3500

Extra bedroom: 150 gallons each.

Extra dwelling units over 10: 250 gallons each.

Extra fixture units over 100: 25 gallons per fixture unit.

16.6.2 Reserved

16.6.3 Multiple Compartment

In a tank of more than one compartment, the inlet compartment shall have a capacity of not less than two-
thirds of the total tank capacity.

Comment: Septic tanks with two compartments operate more efficiently than single-compartment tanks
at removing solids in the effluent. The liquid that enters the second compartment is already substantially
clarified. There is less turbulence in the second chamber, which permits finer suspended solids to settle
out.

16.6.4 Septic Tank Materials

See Sections 3.3.1 1, 16.6.5 and 16.6.6.

Comment: Modern septic tanks are typically constructed of concrete (pre-cast), polyethylene, or fiber-
glass. Steel septic tanks are prohibited by many jurisdictions because of leakage due to corrosion.

16.6.5 Steel Tanks

Comment: Steel septic tanks are no longer approved by most jurisdictions because of leakage due to
corrosion. The average life expectancy of a steel septic tank is only 7 years.

J 6.6.5.1 Welding

All steel tanks shall be continuous welded. (No spot welding is permitted.)

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16.6.5.2 Wall Thickness

The minimum waJl thickness of any steel septic tank shall be No. 12 U.S. gauge (0.109").

16.6.5.3 Coatings

Metal tanks shall be coated inside and out with an approved coating.

16.6.5.4 Baffles

The inlet and outlet baffles shall be at least 12 inches in diameter at the point opposite the opening in
the tank.

16.6.5.5 Pumpout Opening

The pumpout opening in the top shall be large enough to permit a 6-inch cast-iron pumpout pipe to be
inserted with a shoulder to support this pipe.

16.6.5.6 TankOpening

The tank opening shall not be smaller than 6 inches with a 3-inch collar.

16.6.5.7 Outside Diameter of Collar

The outside diameter of this collar shall be 8 inches.

16.6.5.8 Pumpout Pipe

The pumpout pipe shall terminate at the surface and a 6-inch iron body brass cleanout shall be caulked
into the hub of this pipe with oakum and molten lead; the cleanout nut shall be solid brass no smaller
than one inch.

16.6.5.9 Manhole

There shall be a 24 x 24-inch manhole held in position by four 3/8" bolts securely welded in place.

16.6.5.10 Partition

There shall be a supporting partition welded in the center of these tanks as per drawings.

1 6.6.5.1 1 Partition Openings

This partition shall have 2-inch openings at intervals at the top for air circulation.

16.6.5.12 Capacity, Gauge Metal and Weight

The capacity, gauge metal, and weight must be stamped on a brass plate and welded to the top of
metal septic tanks.

16.6.6 Concrete Tanks

16.6.6.1 Baffles

Concrete tanks shall have the same size baffles and pumpout openings as for steel tanks.

•

2006 National Standard Plumhinn Cude-lltusmiled 343

16.6.6.2 Tops

The tops shall have a 24-inch manhole with handle to remove same, or be cast in three or four sections
cemented in place.

16.6.6.3 Wall Thickness

The minimum thickness of the walls shall be 2-3/4 inches.

1 6.6.6.4 Tops and Bottoms

The tops and bottoms shall be 4 inches thick unless placed under a driveway, then they shall be a
minimum of 6 inches.

16.6.6.5 Walls and Bottoms

All tank walls and bottoms shall be reinforced with approved reinforcing.

16.6.6.6 Top Reinforcing

The tops shall have 3/8 inch steel reinforcing on 6-inch centers.

16.6.6.7 Watertight

The tank shall be watertight.

16.6.7 Depth of Septic Tank

The top of the septic tank shall be brought to within 36 inches of the finished grade. Where a greater depth is
permitted by the Authority Having Jurisdiction, the access manhole must be extended to the finished grade
and the manhole shall have a concrete marker at grade.

Comment: The typical depth of cover on the top of a septic tank is 12" - 18". Where the depth of cover
exceeds 36", the structural design of the tank must be adequate for the imposed earth loads.

16.6.8 Limitation

No septic tank shall serve more than one property unless authorized by the Authority Having Jurisdiction.

16.6.9 Effluent

The effluent from all septic tanks shall be disposed of underground by subsurface irrigation or seepage pits or
both.

16.7 DISTRIBUTION BOX

16.7.1 When Required

A distribution box shall be required when more than one line of subsurface irrigation or more than one seep-
age pit is used.

Comment: The minimum distances from distribution boxes to the septic tank, disposal field, seepage pit,
dry well, potable water wells, or suction lines from potable water wells must be in accordance with Table
16.43.

•

344 2006 National Standard Plumbum. Code-Illustrated

•

16.7.2 Connection

Each lateral line shall be connected separately to the distribution box and shall not be subdivided.

16.7.3 Invert level

The invert of all distribution box outlets shall be at the same level and approximately 2 inches above the
bottom of the box. The inlet invert shall be at least 1 inch above the invert of the outlets. The size of the
distribution box shall be sufficient to accommodate the number of lateral lines.

16.7.4 Watertight

The distribution box shall be of watertight construction arranged to receive the septic tank effluent and with
an outlet or connecting line serving each trench or seepage pit.

16.7.5 Baffle

A baffle at least 6 inches high and 1 2 inches long shall rest on the bottom of the box and be placed at right
angles to the direction of the incoming tank effluent and 1 2 inches in front of it.

16.7.6 Reserved

16.7.7 Inspection

The sides of the box shall extend to within a short distance of the ground surface to permit inspection, and
shall have a concrete marker at grade.

16.8 SEEPAGE PITS

16.8.1 Use

Seepage pits may be used either to supplement the subsurface disposal field or in lieu of such field where
conditions favor the operation of seepage pits, as may be found necessary and approved by the Authority
Having Jurisdiction. See Figure 1.2.41 and the definition of "Leaching Well or Pit"

16.8.2 Water Table

Seepage pits shall not penetrate the water table.

16.8.3 Septic Tank Effluent Disposal

Where seepage pits are used for septic tank effluent disposal, the number, diameter and depth of the pits shall
be determined after percolation tests have been made to ascertain the porosity of the soil. See Section
16.5.5

16.8.4 Excavation

The excavation for a seepage pit shall be greater in diameter than the outside diameter of the vertical
sidewalls to allow for the footing.

16.8.5 Annular Space

The annular space between the outside of the vertical walls and the excavation shall be backfilled with broken
stone, coarse gravel, or other suitable material.

2006 National Standard Pluntbins Code-Illustrated 345

16.8.6 Construction

Seepage pits shall be constructed with the bottom being open with an outer ring, or footing, to support the
sidewalls.

16.8.7 Sidewalls

The sidewalls shall be made of pre-cast concrete, stone, concrete or cinder blocks, or brick laid in cement
mortar for strength, with openings at sufficient intervals to permit the septic tank effluent to pass out through
the wall to the surrounding porous soil.

16.8.8 Cover Strength

All septic tank tops and seepage pit covers shall be of sufficient strength to carry the load imposed. Seepage
pit covers shall be at least as required in Sections 16.8.9, 16.8.10, and 16.8.1 1.

16.8.9 Pre-CastTop

Seepage pit tops shall be pre-cast, reinforced concrete (2,500 pounds per square inch minimum compressive
strength) not less than 5 inches thick and designed to support an earth load of not less than 400 pounds per
square foot. Each such cover shall extend not less than 3 inches beyond the sidewalls of the pit, shall be
provided with a 6-inch minimum inspection hole with pipe extended to the surface, and a 6-inch cast-iron
standpipe with cleanout at grade.

16.8.10 Depth Below Grade

The top shall be at least 36 inches below finished grade, except where less is permitted by the Authority
Having Jurisdiction.

16.8.11 Field Fabricated Slabs

Where field fabricated slabs are used. Table 16.8.1 1 indicates the requirements.

•

Table 16.8.11

DESIGN OF SEEPAGE PIT COVERS

Pit

Pit Wall Cover

Cover

Reinforcing Steel Req'tl in

Diameter

Thickness Thickness

Weight

Two Perpendicular

Directions

5ft.

4" 5"

12301b

#5 @ lO'/V'c/c

6ft.

8" 5"

1 770 lb

#5 @ 9" c/c

8ft.

8" 6"

37801b

U5 @ 77:" c/c

10ft.

8" 8"

78501b

#5 @ 6V2" c/c

16.9 ABSORPTION TRENCHES

16.9.1 General

Absorption trenches shall be designed and constructed on the basis of the required effective percolation area.

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2006 National Standard Plumbing Code-HlustranJ

•

16.9.2 Filter Material

The filter material shall cover the tile and extend the full width of the trench and shall be not less than 6
inches deep beneath the bottom of the tile, and 2 inches above the top of the tile. The filter material may be
washed gravel, crushed stone, slag, or clean bank-run gravel ranging in size from 1/2 to 2-1/2 inches. The
filter material shall be covered with burlap, filter cloth, 2 inches of straw, or equivalent permeable material
prior to backfilling the excavation.

16.9.3 Absorption Field

The size and minimum spacing requirements for absorption fields shall conform to those given in Table 1 6.9.3.

Table 16.9.3
SIZE AND SPACING FOR DISPOSAL FIELDS

Width of
trench at
bottom
(in.)

depth of

acing tile

trench

lines'

(in.)

(ft.)

1 8 to 30

6.0

18 to 30

6.0

18 to 36

7.6

24 to 36

9.0

Effective
absorption area
per lineal ft. of
trench (sq. ft.)

18
24
30
36

. A greater spacing is desirable where available area permits.

1.5
2.0
2.5
3.0

16.9.4 Lateral Length

Length of laterals shall not exceed 1 00 feet.

Comment: Where the length of lateral tiles in Section 16.5.4 exceeds 100 feet, two or more laterals must
be provided.

16.9.5 Absorption Lines

Absorption lines shall be constructed of 4" pipe of open jointed or perforated vitrified clay pipe, open jointed or
horizontally split or perforated clay tile, perforated plastic pipe or open jointed cast iron soil pipe, all conform-
ing to approved standards. In the case of clay tile, open jointed clay pipe, or open jointed cast-iron soil pipe,
the sections shall be spaced not more than 1/2 inch apart, and the upper half of the joint shall be protected by
asphalt-treated paper while the piping is being covered.

16.9.6 Grade

The trench bottom shall be uniformly graded to slope from a minimum of 2 inches to a maximum of 4 inches
per 100 feet.

16.10 RESERVED

2006 Natiuiuil Standard Plumbing Code-lllusiraltd

347

16.11 PIPING MATERIAL

See Chapter 3.

Comment: Refer to Section 3.5 and Table 3.5 for approved materials for drainage piping. Refer to
Section 16.9.5 and Table 3.8 for approved materials for sub-soil drainage and absorption lines.

16.12 SAND FILTERS

16.12.1 General Specifications for Design and Construction of a Sand Filter with Chlorination

16.12.1.1 General

A sand filter shall consist of a bed of clean, graded sand on which septic tank effluent is distributed by
means of a siphon and pipe, with the effluent percolating through the bed to a series of underdrains
through which it passes to the point of disposal. See the definition of "Sand Filter" and Figure
1.2.51.

16.12.1.2 Filter Size

The filter size shall be determined on the basis of 1 .15 gallons per square foot per day if covered, and
2.3 gallons per square foot per day if an open filter is to be used.

16.12.1.3 Dosing Tank Size

The septic tank effluent shall enter a dosing siphon tank of a size to provide a 2-inch coverage of the
sand filter.

16.12.1.4 Siphon

The siphon shall be of a commercial type and shall discharge the effluent to the sand filter intermit-
tently. The siphon shall be omitted if a pump is used to lift the septic tank effluent to the sand filter.

16.12.1.5 Surge Tank

A surge tank shall be used to receive the pump discharge prior to dosing on the sand filter.

16.12.1.6 Underdrains

Four-inch diameter vitrified clay pipe in 2-foot lengths laid with 1/2 inch openjointsorunglazedfarm
tile in 1 -foot lengths laid with open joints, with the top half of each joint covered with 4-inch wide strips
of tar paper, burlap, or copper screen, or perforated bituminized-fiber pipe or other approved material
shall be used for the underdrains.

16.12.1.7 UnderdrainBed

The underdrains shall be laid at the bottom of the sand filter, surrounded by washed gravel, crushed
stone, slag, or clean bank-run gravel ranging in size from 1/2 inch to 2-1/2 inches and free of fines,
dust, ashes or clay. The gravel shall extend from at least 2 inches below the bottom of the tile to a
minimum of 2 inches above the top of the tile.

348 2006 National Standard Plumbing Code-lllustratvd

16.12.1.8 Underdrain Slope and Spacing

The underdrains shall have a slope from 2 inches to 4 inches per 100 feet and shall be placed at 6-foot
to 8-foot intervals.

16.12.1.9 Underdrain Fill

Above the gravel or other material surrounding the underdrain shall be placed 2 feet of washed and
graded sand having an effective size of from 0.35-0.5 mm and a uniformity coefficient of not over 3.5.
(The effective size of a sand filter is that size of which 10% by weight is smaller and the uniformity
coefficient is the ratio of that size of which 60% by weight is smaller to the effective size.)

16.12.1.10 Distribution Pipes

The distribution pipes shall be laid at the surface of the sand filter, surrounded by gravel as specified
for the underdrains.

16.12.1.11 Gravel Cover

The gravel should be covered with untreated building paper and the entire area covered with a mini-
mum of 12 inches of earth if the filter is to be covered.

16.12.1.12 Open Filter

If the filter is an open one, the four sides shall be constructed of wood or concrete to prevent earth
erosion from entering the sand filter bed.

16.12.1.13 Chlorine Contact Tank

The chlorine contact tank for disinfection of sand filter effluent shall provide 20 minutes detention at
average flow, but in no case shall it be smaller than 50 gallons capacity. Chlorine control should be
provided by the use of hypochlorite or chlorine machines commercially available.

2006 National StanJanl Plumbing Coi/c-lllustnucd 349

Blank Page

350 200b National Standard Plumbing Code-lHusiraieJ

Chapter 17

Potable Water Supply Systems

17.1 GENERAL REGULATION

17.1.1 Jurisdiction

The regulations in this chapter apply to any water system where plumbing fixtures are installed for human
occupancy.

Comment: This chapter applies to private water supply systems serving one or more
buildings independent of any public water supply.

17.1.2 Pumps

Pumps shall be installed only in wells, springs and cisterns that comply with the rules and regulations as
determined by the Authority Having Jurisdiction.

17.2 QUANTITY OF WATER REQUIRED

17.2.1 Single Dwelling Unit

The minimum capacity of the system in gallons per minute shall equal the number of fixtures installed.

Comment: A capacity of 1 GPM per fixture in a single dwelling unit is a rough rule of
thumb. The peak demand should be verified using Tables 10.14.2A and 10A4.2B. See
Section 17.2.4 where well yields do not satisfy the peak demand.

17.2.2 Other Than a Single Dwelling Unit

In other than a single dwelling unit, the water system shall be designed in accordance with Tables 1 0. 14.2 A,
and 10J4.2B and shall be capable of supplying the maximum demand to the system according to usage, but,
in no case, less than for a minimum period of 30 minutes.

Comment: See Section 10.14.3 for determining the peak demand on the potable water
supply system.

2006 National Standard Plumbing Code-llfitstraicd

351

17.2.3 Available Water

Total water available during any 24-hour period shall not be less than the requirements of Table 16.3.7.

Comment: Table 16.3.7 indicates the daily design sewage flows from various establish-
ments. The available water supply must be able to satisfy this daily volume requirement, as
well as the peak GPM demand.

17.2.4 Secondary Sources of Water

a. When the available primary source of water does not meet the minimum requirement of Sections 17.2.1,
1 7.2.2, and 17.2.3, one of the following methods shall be used:

1 . Pressure tank of sufficient size.

2. Gravity tank, see Section 10.8.

3. Two pump system.

(a) The capacity of the first well pump shall not exceed the well capacity in flow. This pump supplies
water to another tank that stores the water at atmospheric pressure and has a control to start and stop the
pump.

(b) The second pump delivers the water to a hydropneumatic tank at the required pressure and quantity.

Comment: Where the primary potable water supply source cannot provide sufficient
volume to satisfy the 24-hour demand of the water distribution system, water storage facili-
ties must be provided.

17.3 PRESSURE

Pressure shall be as required in Section 10.14.3.

Comment: Private potable water supply systems must provide adequate pressure for
fixtures to deliver the flow rates for the various fixtures listed in Section 10.14.2.

17.4 PIPING MATERIALS

Piping from the well to inside of the dwelling shall be as required in Section 3.8.

Comment: See Sections 3.4.1 and 3.4.2 for general requirements. See Table 3.4 for
approved materials for water service piping.

17.5 STORAGE TANKS

Storage equipment shall be as follows:

17.5.1 Certified Tanks

All tanks shall be certified under Water Systems Council Standards for size and pressure.

17.5.2 Tank Material

All tanks shall be coated or made of material to resist corrosion.

352

2006 National Standard Plumbing Code-Illustrated

17.5.3 Pressure Rating

Hydropneumatic tanks shall have a working pressure rating in excess of the maximum required system
pressure.

17.5.4 Non-Toxic Materials

All tanks shall be constructed of materials and/or coatings that are non-toxic.

17.5.5 Drain Required

All tanks shall be provided with a means for draining.

17.5.6 Covers

Atmospheric storage tanks shall be provided with a cover as required in Section 10.8.

17.6 PUMPS

17.6.1 Certified Pumps

Pumps shall be certified under Water Systems Council Rating and Rating Standards.

Comment #/: Well pumps for private water supplies include shallow well jet pumps, deep
well jet pumps, and submersible pumps.

Comment #2: Jet pumps circulate water through an ejector fitting that develops a vacuum
and draws water from the well. Shallow well jet pumps are used for wells less than 25 feet
deep and have the ejector fitting located outside of the well. Deep well jet pumps can be
used for wells up to 75 feet deep and have the ejector fitting located within the well casing.
Some jet pumps are convertible and can be used for either one-pipe shallow well or two-pipe
deep well installations, although their rated capacity is less for deep wells than for shallow
wells.

Comment #3: Submersible well pumps are located at the bottom of the drop pipe within the
well casing. Submersible well pumps can lift water up to 500 feet or more.

17.6.2 Installation

Pumps shall be installed in accordance with the manufacturer's recommendations.

17.6.3 Equipment Installation

Pumping equipment shall be installed to prevent the entrance of contamination or objectionable material either
into die well or into the water that is being pumped.

17.6.4 Pump Location

The pump shall be located to facilitate necessary maintenance and repair, including overhead clearance for
removal of drop pipe and other accessories.

2006 National Standard Plumbing Code-llhistraied 353

17.6.5 Pump Mounting

The pump shall be suitably mounted to avoid objectionable vibration and noise, and to prevent damage to
pumping equipment.

17.6.6 Pump Accessories

The pump controls and/or accessories shall be protected from weather.

17.7 PUMP DOWN CONTROL

17.7.1 Tailpipe

30 feet of tailpipe shall be installed below the jet on deep well installation.

17.7.2 Switches

Low pressure cut-off switch and/or water level cut-off switch shall be installed.

17.7.3 Suction Pipe

Use a vertical suction pipe of 30-foot length on shallow well jet installation.

17.8 CONTROLS

a. The following controls are required on all pump installations:

1. Pressure switch

2. Thermal overload switch

3. Pressure relief valve on positive displacement pumps

4. Low water cut-off switch where the pump capacity exceeds the source of water.

17.9 WELL TERMINAL

17.9.1 Upper Well Terminal

Well casing, curbs and pitless adapters shall terminate not less than eight inches above the finished ground
surface or pump house floor and at least 24 inches above the maximum high water level where flooding
occurs. No casing shall be cut off or cut in below ground level except to install a pitless adapter.

17.9.2 Pitless Adapter

17.9.2.1 Design

Pitless adapters designed to replace a section of well casing or for attachment to the exterior of a well
casing shall be constructed of materials that provide strength and durability equal to the well casing.

17.9.2.2 Installation

Installation shall be by threaded, welded or compression-gasketed connection to cutoff casing or
attachment to the exterior wall of the casing and shall be watertight.

17.9.23 AdapterUnits

Adapter units designed to replace a section of the well casing shall extend above the finished ground
surface as provided in Section 17.9.1. The top of the adapter unit shall be capped with a cover having a

354 2006 National Standard Plumbing Code-Illustrated

•

downward flange that will overlap the edge of the unit. The cover shall be securely fastened to the unit
and shall fit sufficiently snug to the unit to be vermin proof. The cover shall provide for watertight
entrance of electrical cables and vent piping or air line if installed.

17.9.3 Hand Pumps

17.9.3.1 General

Hand pumps shall be of the force type equipped with a packing gland around the pump rod, a delivery
spout that is closed and downward directed, and a one-piece bell type base that is part of the pump
stand or is attached to the pump column in a watertight manner.

17.9.3.2 Installation

The bell base of the pump shall be bolted with a gasket to a flange that is securely attached to the
casing or pipe sleeve.

1 7.9.4 Power Driven Pumps

17.9.4.1 General

The design and operating principles of each type of power driven pump determines where each may be
located with respect to a well. The location selected for the pump determines what factors must be
considered to make an acceptable installation.

17.9.4.2 Location Above Well

Any power driven pump located over a well shall be mounted on the well casing, pipe sleeve, pump
foundation or pump stand such that a watertight closure is or can be made for the open end of the
casing or sleeve.

17.9.4.3 Pump Base

The pump base bolted with a neoprene or rubber gasket or equivalent watertight seal to a foundation or
plate provides an acceptable seal.

17.9.4.4 Large Pump Installation

On large pump installations, the bolting may be omitted when the weight of the pump and column is
sufficient to make a watertight contact with the gasket.

1 7.9.4.5 Pump Location Other Than Over Casing

If the pump unit is not located over the casing or pipe sleeve, the pump delivery or suction pipes
emerge from the top of the well, a watertight expanding rubber seal or equivalent shall be installed
between the well casing and piping to provide a watertight closure.

17.9.4.6 Seal Top

The top of the seal shall not extend below the uppermost edge of the casing or pipe sleeve.

1 7.9.5 Location in Well For Submersible Pumps
17.9.5.1 General

This type of location is permissible for submersible pumps only.

2006 National Standard PlunihinQ Code-Illustrated 355

1 7.9.5.2 Top Discharge Line

When the discharge line leaves the well at the top of the casing, the opening between the discharge line
and casing or pipe sleeve shall be sealed watertight with an expanding rubber seal or equivalent device.

17.9.5.3 Underground Discharge

When an underground discharge is desired, a properly installed pitless adapter shall be used. A check-
valve shall be installed in the discharge line above the pump in the well.

1 7.9.5.4 Top Discharge Line Sloped to Drain to Well

When the discharge pipe leaves the well at the top, remains above ground, and slopes to drain back to
the well, the check-valve can be located beyond the well.

17.9.6 Offset from Well

17.9.6.1 Location

Pumps offset from the well, if not located in an above-ground pump house or other building, may be
located in an approved basement provided the pump and all suction pipes are elevated at least 12
inches above the floor.

17.9.6.2 Buried Lines

All portions of suction lines buried below the ground surface between the well and the pump and that
are not enclosed in a protective pipe shall be located the same minimum distance from sources of
contamination as are prescribed for the well in Section 1 6.4.3.

17.9.6.3 Protective Pipe

When these minimum distances cannot be obtained, the suction line shall be enclosed in a protective
pipe of standard thickness from the well to the pump. The protective pipe shall be sealed watertight at
both ends. This requirement shall be considered satisfied if the suction line lies within a pressure
discharge line.

17.10 VENTS

17.10.1 Size

All vent piping shall be of adequate size to allow equalization of air pressure in the well and shall not be less
than one-half inch in diameter.

17.10.2 Toxic or Flammable Gases

Particular attention shall be given to proper venting of wells and pressure tanks in areas where toxic or
flammable gases are known to be a characteristic of the water. If determined that either of these types of
gases are present, all vents when located in buildings shall be extended to discharge outside of the building at
a height where they will not be a hazard.

17.10.3 Vent Extension

The vent shall extend above the upper terminal of the well with the end downturned and covered with not less
than 16 mesh screen wire. The point of entry into the well shall be sealed watertight.

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17.11 PUMP BEARING LUBRICATION

17.11.1 General

Lubrication of bearings of power driven pumps shall be with water or oil that will not adversely affect the
quality of the water to be pumped.

17.11.2 Water Lubrication

If a storage tank is required for the lubrication water, it shall be designed to protect the water from contami-
nation.

17.11.3 Oil Lubrication

The reservoir shall be designed to protect the oil from contamination. The oil shall not contain substances that
will cause odor or taste to the water pumped.

17.12 WATER LEVEL MEASUREMENT

On wells of large capacity where access for measuring the water level in the well is provided, piping for this
purpose shall terminate above the upper well terminal, be capped or otherwise closed, and all openings around the
piping at the point of entry into the well sealed watertight.

17.13 PROHIBITED PUMPS

No pitcher or chain-bucket pump shall be installed on any water supply.

17.14 PUMP HOUSING

17.14.1 Watertight

A separate structure housing the water supply and pumping equipment shall have an impervious floor and
rain-tight walls and roof.

17.14.2 Pump Pit

A pump pit shall be of watertight construction and provided with a positive drain or sump pump to keep the pit
dry.

17.15 CROSS CONNECTION

17.15.1 Restriction

There shall be no cross-connection between an individual water supply system and other individual or public
water supply system.

17.15.2 Limitations

No water supply shall serve more than one property unless authorized by the Authority Having Jurisdiction.

2006 National Standard Pfumbins Code-Illustrated 357

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358 200b National Standard Plumbing Code-lllusiraitJ

•

Chapter 18

Mobile Home & Travel Trailer Park
Plumbing Standards

The primary objective of this Chapter is to assure sanitary plumbing installations in trailer home parks. Reference
should be made to the Authority Having Jurisdiction and the regulations promulgated by the Authority Having
Jurisdiction governing the establishment and operation of trailer home parks.

18.1 DEFINITIONS

Comment: The requirements of this chapter are intended as general requirements for parks and
campgrounds that serve travel trailers, recreational vehicles, and mobile homes. Travel trailers and
recreational vehicles are used as temporary dwellings for travel or recreational purposes. Mobile
homes are movable structures or units that are designed as living quarters. The requirements of the
Authority Having Jurisdiction may vary for the different types of parks and campgrounds.

Service Buildings

A building housing toilet, laundry and any other such facilities as may be required.

Sewer Connection

Sewer connection is that portion of the drainage piping that extends as a single terminal under the trailer
coach for connection with the trailer park drainage system.

Trailer Coach

Any camp-car, trailer, or other vehicle with or without motive power, designed and constructed to travel on
the public thoroughfares in accordance with provisions of the Vehicle Code and designed or used for human
habitation.

Trailer Coach, Dependent

One which is not equipped with a water closet for sewage disposal.

Trailer Coach, Independent

One which is equipped with a water closet for sewage disposal.

Trailer Coach Drain Connection

The removable extension connecting the trailer coach drainage system to the trailer connection fixture.

Trailer Coach, Left Side

The side farthest from the curb when the trailer home is beinR towed or in transit.

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359

Trailer Connection Fixture

A connection to a trap that is connected to the park drainage system, and receives the water, liquid or other
waste discharge from a trailer coach.

Trailer Park Drainage System

The entire system of drainage piping used to convey sewage or other waste from a trailer connection fixture
to the sewer.

Trailer Park Branch Line

That portion of drainage piping that receives the discharge from not more than two trailer connection fixtures.

Trailer Park

Any area or tract of land where space is rented or held-out for rent, or occupied by two or more trailer
coaches.

Trailer Park Sewer System

That piping that extends from the public or private sewage disposal system to a point where the first trailer
park drainage system branch fitting is installed.

Trailer Park Water Service Main

That portion of the water distribution system that extends from the street main, water meter, or other source
of supply to the trailer site water service branch.

Trailer Site

That area set out by boundaries on which one trailer can be located.

Trailer Site Water Service Branch

That portion of the water distributing system extended from the park service main to a trailer site, and in-
cludes connections, devices, and appurtenances thereto.

Water Service Connection

That portion of the water supply piping that extends as a single terminal under the trailer coach for connection
with the trailer coach park water supply system.

18.2 STANDARDS

18.2.1 General

Plumbing systems hereafter installed in trailer home parks shall conform to the provisions set forth in the
preceding chapters of this Code, where applicable, and also to the provisions set forth in this Chapter. Trailer
home park plumbing and drainage systems shall, in addition, conform to all other applicable Authority Having
Jurisdiction regulations.

18.2.2 Plans and Specifications

Before any plumbing or sewerage disposal facilities are installed or altered in any trailer park, duplicate plans
and specifications shall be filed, and proper permits obtained from the Authority Having Jurisdiction. Plans
shall show in detail.

360 2006 i\'utioncil Sumdard Plumbing Code -Illustrated

18.2.2.1 PlotPlan

Plot plan of the park, drawn to scale, indicating elevations, property lines, driveways, existing or pro-
posed buildings, and sizes of trailer sites.

18.2.2.2 Plumbing Layout

Complete specifications and piping layout of proposed plumbing system or alteration.

18.2.2.3 Sewerage Disposal Layout

Complete specifications and piping layout of proposed sewer system or alteration. See Sections 3.4,
3.5, 3.6, and 3.7.

18.2.2.4 Conformance

Trailer park plumbing system shall be designed and installed in accordance with the requirements of this
Code and shall, in addition, conform to all other pertinent local ordinances and State regulations.

18.2.3 Materials

Materials shall conform to the approved standards set forth in other sections of this Code.

18.3 SEWER

1 8.3.1 Design and Installation

The trailer park drainage system shall be designed and installed in accordance with the requirements of this
Code.

18.3.2 Alternate

The trailer park drainage system may be installed by the use of a combination waste and vent drainage system
(see Section 12.17), which shall consist of an installation of waste piping, as hereinafter provided in this
Section, in which the traps for one or more trailer connection fixtures are not separately or independently
vented, but which is vented through the waste piping of such size to secure free circulation of air therein.
See Sections 12.17 for combination waste and vent systems.

1 8.3.3 Each Independent Trailer Site

Each independent trailer site shall be provided with a trapped trailer connection that shall consist of a three-
inch horizontal iron pipe-size threaded connection, installed a minimum of three inches and a maximum of six
inches (from the bottom of the connection), above the finished grade. The vertical connection to the trailer
connection fixture shall be anchored in a concrete slab four inches thick, and 1 8" x 1 8" square.

18.3.4 AboveGround

Any part of the plumbing system extending above the ground shall be protected from damage when deemed
necessary by the Authority Having Jurisdiction.

18.3.5 Trap Connections

Each trailer site shall be provided with a three-inch l.P.S. male or female threaded connection, extended
above the surrounding grade, from a three- inch minimum size vented p-trap.

7000 National Standard Plumbing Code-Illustrated 361

18.3.5.1 Location

Traps shall be located with reference to the immediate boundary lines of the designated space or area
within each trailer site that will actually be occupied by the trailer. Each such trap shall be located in
the rear third-quarter section along the left boundary line of the trailer parking area not less than one
foot or more than three feet from the road side of the trailer and shall be a minimum of five feet from
the rear boundary of the trailer site. This location may be varied by permission of the Authority Having
Jurisdiction when unusual conditions are encountered.

18.3.5.2 Material

All traps, tail pipes, vertical vents, the upper five feet of any horizontal vent, and the first five feet of
any trap branch shall be fabricated from materials approved for use within a building. See Sections
3.5 and 3.6.

18.3.6 Restriction

No vertical pipe shall be used in a special waste and vent system. .except the vent pipe, and the connection to
the trailer connection fixture.

18.3.7 Drain Connections

Mobile home and travel trailer drain connections shall be of approved semi-rigid or flexible reinforced hose
having smooth interior surfaces and not be less than a 3-inch inside diameter. Main connections shall be
equipped with a standard quick-disconnect screw or clamp type fitting, not smaller than the outlet. Main
connections shall be gas-tight and no longer than necessary to make the connection between the trailer coach
drain connection and the trailer connector fixture on the site.

18.3.8 Cleanouts

Cleanouts shall be provided as required by Chapter 5 of this Code, except cleanouts shall be provided in the
vent stacks one foot above grade.

18.3.9 Fixture Unit Loading

For the purpose of determining pipe sizes, each trailer site connection shall be assigned a waste loading
value of six fixture units and each trailer park drainage system shall be sized as provided in Table 18.3.12.
Private sewage disposal shall conform to the requirements of Chapter 16 of this Code. See Table 18.3.12
and Chapter 16.

18.3.10 Slope

The grade on sewers shaJl provide a minimum velocity of two feet per second when the pipe is flowing half
full. See Table K-2 in Appendix K.

18.3.11 Discharge

The discharge of the park drainage system shall be connected to a public sewer. Where a public sewer is not
available within 300 feet for use, an individual sewage disposal system of a type that is acceptable and
approved by the Authority Having Jurisdiction shall be installed.

•

Comment: It is preferred that trailer parks be connected to public sewers, even if more than 300 feet
away. Trailer sites are typically densely spaced to maximize the use of the property, which leaves little
space for an adequate on-site sewage disposal system.

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18.3.12 Minimum Pipe Size

Minimum pipe size of the drainage system shall be as set forth in Table 8.3.12.

Table 18.3.12
DRAIN PIPE SIZING

Max. No. of Trailers,
Individually Vented
Systems

Max. No. of Trailers,
Wet-Vented
Systems

Size of Drain

100

400

1000

3"
4"
6"
8"
10"

18.4 VENTING

18.4.1 Location

Each wet-vented drainage system shall be provided with a vent not more than 1 5 feet downstream from its
upper trap, and long mains shall be provided with additional relief vents at intervals of not more than 100 feet
thereafter. The minimum size of each vent serving a wet-vented system shall be as set forth in Table 18.4.1.

Table 18.4.1

VENT SIZING

Size of Wet-Vented Drain

Minimum Size of Vent

3"
4"
5"
6"

2"
3"
4"

18.4.2 Reserved

18.4.3 Reserved

18.4.4 Reserved

18.4.5 Vent Connections

All vent intersections shall be taken off above the center line of the horizontal pipe. All vent stacks shall be
supported by a four-inch by four-inch redwood post, set in at least two feet of concrete extending at least
four inches above the ground, or supported by another approved method.

Comment: Treated lumber is considered to be the equivalent of redwood.

18.4.6 Galvanized Steel Vent Pipe

Galvanized steel vent pipe may extend below the ground vertically, and may directly intersect a drainage line
with an approved fitting, if the entire section around both the drain and the galvanized pipe is encased in
concrete to prevent any movement. Galvanized steel pipe encased in concrete shall be first coated with
bituminous paint, orequivalent protective material.

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363

18.4.7 Location of Vent Pipes

Vent pipes shall be located at least 10 feet above grade and 10 feet from the property line. No vent shall
terminate directly beneath any door, window, or other ventilating openings of the building or of an adjacent
building, nor shall any such vent terminal be within 1 feet horizontally of such opening unless it is at least 2
feet above the top of such opening.

18.4.8 Size of Vent Stack

All vent stacks in the wet-vented system shall be three inches or more in diameter, except that a three-inch
branch line may be vented by a two-inch vent. See Table 18.4.1.

18.4.9 Branch Lines

No three-inch branch line shall exceed six feet in length, and no four-inch branch shall exceed 15 feet in
length, unless they are properly vented.

18.4.10 Trailer Connections

Each trailer connection fixture outlet shall be provided with a screw-type plug or cap, and be effectively
capped when not in use.

18.5 WATER DISTRIBUTION SYSTEM

18.5.1 Conformance

Each trailer park water distribution system shall conform to the requirements of Chapter 10 of this Code and
shall be so designed and maintained as to provide a residual pressure of not less than 20 psi at each trailer site
under normal operating conditions. (See Table 10.14.3.) Refer to Appendix B for sizing the water
distribution systems.

18.5.2 Individual Water Service Branch

Every trailer site shall be provided with an individual water service branch line that shall not be less than 3/4"
size, delivering safe, potable water.

18.5.3 Connection Components

A control valve shall be installed on the water service branch, followed by an approved backflow preventer in
accordance with ASSE 1024 or CSA B64.6 on the discharge side of the control valve, with a pressure relief
valve located on the discharge side of the backflow preventer, with a hose connection or other approved
attachment on the trailer side of the relief valve. Each such pressure relief valve shall be equipped with a full-
size drain with the end of the pipe not more than two feet or less than six inches above the ground and pointing
downward. Such drain may terminate at other approved locations. No part of such drain pipe shall be trapped.
No shut-off valve shall be installed between any such pressure relief valve and the trailer it serves. The
backflow device and relief valve shall be located not less than 12 inches above the grade.

18.5.4 Connection Details

The service connection shall not be rigid. Flexible metal tubing is permitted. Fittings at either end shall be of a
quick disconnect type not requiring any special tools or knowledge to install or remove.

18.5.5 Water Fixture Units

Each trailer outlet on the water distribution svstem shall be rated as six water fixture units.

364 2006 National Siaiuknd Plumbing Code-Illustrated

18.5.6 Location of Water Connection

The trailer park water outlet for each trailer coach space shall be located near the center of the left side of
each trailer coach.

18.5.7 Fire Protection

In the design of the water distribution system in a trailer park, consideration for fire outlet stations throughout
the park should be made relative to the location and quantity of water necessary during an emergency
period.

18.5.8 Backflow Protection

All requirements as described in Chapter 10 of this Code shall be considered a part of this Section.

18.6 RESERVED

18.7 TESTING

Installations shall be tested and inspected as required by thisGode.

18.8 SANITARY FACILITIES

1 8.8.1 Public Water Closets, Showers, and Lavatories

Separate public water closets, showers, and lavatories shall be installed and maintained for each sex in
accordance with the following ratio of trailer sites:

18.8.1.1 Dependent Trailer

Trailer parks constructed and operated exclusively for dependent trailers shall have one water closet,
one shower, and one lavatory for each 10 sites or fractional part thereof.

Comment: Dependent trailers are not equipped with u water closet and lavatory and are dependant on
the trailer park for such facilities.

18.8.1.2 Independent Trailer

Trailer parks constructed and operated exclusively for independent trailers shall have one water closet,
one shower, and one lavatory for each 100 sites or fractional part thereof.

Comment: Independent trailers are equipped with a water closet and lavatory and are not dependent
on the trailer park for such facilities.

18.8.1.3 Combined Trailer Use

Trailer parks constructed and operated for the combined use of dependent and independent trailers
shall have facilities as shown in Table 1 8.8.1 .3.

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365

Table 18.8.1.3
FACILITIES REQUIRED

Sites Water Closets Showers Lavatories

2-25 1 1 1

26-70 2 2 2

18.8.1.4 Additional Water Closets

For combined trailer use, one additional water closet shall be provided for each 100 sites or fractional
part thereof in excess of 70 sites.

Comment: Section 18.8.1.4 applies to trailer parks with combined-trailer use,MS in Section 18.8.1.3.

18.8.2 Exclusivity

Each toilet facility shall be for the exclusive use of the occupants of the trailer sites in the trailer park.

18.8.3 Showers

In every auto and trailer park, shower bathing facilities with hot and cold running water shall be installed in
separate compartments. Every compartment shall be provided with a self-closing door or otherwise equipped
with a waterproof draw curtain.

18.8.4 Laundry Facilities

Every trailer park shall be provided with an accessory utility building containing at least one mechanical
washing machine or laundry tray equipped with hot and cold running water for every 20 trailer sites or
fractional part thereof, but in no case shall there be less than two laundry trays in any trailer park.

18.8.5 Shower Compartments

The inner face of walls of all shower compartments shall be finished with cement, concrete, metal, tile or
other approved waterproof materials extending to a height of not less than six feet above the floor. Floors or
shower compartments shall be made of concrete or other similar impervious material. Floors shall be water-
proof and slope 1/4 inch per foot to the drains.

18.9 MAINTENANCE

All required devices or safeguards shall be maintained in good working order. The owner, operator, or lessee of
the trailer park, or his designated agent shall be responsible for the maintenance.

18.10 OPERATOR'S RESPONSIBILITY- VIOLATIONS

When it is evident that there exists, or may exist, a violation of any pertinent regulation, the owner, operator, lessee,
person in charge of the park, or any other person causing a violation shall immediately disconnect the trailer water
supply and sewer connection from the park systems and shall employ such other corrective measures as may be
ordered bv the Authority Having Jurisdiction.

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•

Appendix A

•

Sizing Storm
Drainage Systems

2006 National Standard Plumbing Code-fllustmieJ

367

A.1 Rainfall Rates for Cities

The rainfall rates in Table A.l, RAINFALL RATES FOR CITIES, are based on U.S. Weather Bureau Technical
Paper No. 40, specifically Chart 14: 100-YEAR 1 HOUR RAINFALL (inches) and Chart 7: 1 00-YEAR 30-MINUTE
RAINFALL (inches). The data in Chart 7 were multiplied by 0.72 to determine the rainfall for a 1 5-minute period, then
multiplied by 4 to establish the corresponding rainfall rate in inches perhour. The flow rates in gallons per minute (gpm)
were established by dividing the inches per hour by 1 2 to determine cubic feet per hour per square foot, then multiplying
by 7.48 gallons per cubic foot to determine gallons per hour per square foot, then dividing by 60 minutes per hour to
determine the equivalent gallons per minute.

A.2 Roof Drainage

Primary roof drainage systems are sized for a 100-year, 60-minute storm. Secondary roof drainage systems are sized
for a more severe 100-year, 1 5-minute storm. The rainfall rates in Table A. 1 should be used for design unless higher
rates are established locally.

A.3 Sizing by Flow Rate

Storm drainage systems may be sized by stormwater flow rates, using the appropriate GPM/SF of rainfall listed in
Table A.l for the local area. Multiplying the listed GPM/SF by the roof area being drained (in square feet) produces
the gallons per minute (gpm) of required flow for each drain inlet. The flow rates (gpm) can then be added to determine
the flows in each section of the drainage system. Required pipe sizes can be determined from Table 1 3.6. 1 and Table
13.6.2.

A.4 Sizing by Roof Area

Storm drainage systems may be sized using the roof area served by each section of the drainage system. Required
pipe sizes can be determined from Table 13.6.1 and Table 1 3 .6.2. Using this method, it may be necessary to interpolate
between the various listed rainfall rates (inches perhour). To determine the allowable roof area for a listed size pipe
at a listed slope, divide the allowable square feet of roof area for a 1 " rainfall rate by the listed rainfall rate for the local
area. For example, the allowable roof area for a 6" drain at 1/8" slope with a rainfall rate of 3.2 inches/hour is 2 1400/
3.2 = 6688 square feet.

A.5 Capacity of Rectangular Scuppers

Table A.5 lists the discharge capacity of various width rectangular roof scuppers with various heads of water. The
maximum allowable level of water on the roof should be obtained from the structural engineer, based on the design of
the roof.

•

368 2006 Nuliomil Slumlord Plumbing Code-Illustrated

Table A.l RAINFALL RATES FOR CITIES

STATES AND CITIES

PRIMARY

STORM DRAINAGE

60-MIN DURATION

100-YR RETURN

1N/HR

GPM/SF

SECONDARY

STORM DRAINAGE

1 5-MIN DURATION

100-YR RETURN

IN/HR

GPM/SF

ALABAMA

Birmingham
Huntsville
Mobile
Montgomery

3.7
3.3
4.5
3.8

0.038
0.034
0.047
0.039

7.8

7.5

10.1

8.4

0.081
0.078
0.105
0.087

ALASKA

Aleutian Islands

Anchorage

Bethel

Fairbanks

Juneau

1.0
0.6
0.8
1.0
0.6

0.010
0.006
0.008
0.010
0.006

2.5
1.5
2.0
2.5
1.5

0.026
0.016
0.021
0.026
0.016

ARIZONA

Flagstaff
Phoenix
Tucson

2.3
2.2
3.0

0.024
0.023
0.031

5.2
4.9
5.8

0.054
0.051
0.060

ARKANSAS

Eudora
Fi. Smith
Jonesboro
Little Rock

3.8
3.9
3.5
3.7

0.039
0.041
0.036
0.038

8.6
8.9

7.5
8.6

0.089
0.092
0.078
0.089

CALIFORNIA

Eureka
Lake Tahoe
Los Angeles
Luccmc Valley
Needles
Palmdale
Redding
San Diego
San Francisco
San Luis Obispo

1.5
1.3
2.0
2.5
1.5
3.0
1.5
1.5
1.5
1.5

0.016
0.014
0.021
0.026
0.016
0.031
0.016
0.016
0.016
0.016

3.7
2.9
4.3
4.3
3.7
7.2
3.7
3.7
3.5
3.7

0.038
0.030
0.045
0.045
0.038
0.075
0.038
0.038
0.036
0.038

COLORADO

Craig
Denver
Durango
Stratton

Daytona Beach
Ft. Myers
Jacksonville
Melbourne
Miami
Palm Beach
Tampa
Tallahassee

1.5
2.2

3.0

0.016
0.023
0.019
0.031

3.5
4.6
4.3
6.6

0.036
0.048
0.045
0.069

CONNECTICUT

Hartford
New Haven

2.8
3.0

0.029
0.031

6.6

7.2

0.069
0.075

DELAWARE

Dover
Rehobeth Beach

3.5
3.6

0.036
0.037

7.8
8.6

0.081
0.089

DISTRICT OF COLUMBIA

Washington

4.0

0.042

8.6

0.089

FLORIDA

4.0

0.042

8.6

0089

4.0

0.042

10.1

0.105

4.3

0.045

8.6

0.089

4.0

0.042

8.6

0.089

4.5

0.047

1 1.5

0.119

5.0

0.052

11.5

0.119

4.2

0.044

10.1

0.105

4.1

0.043

9.2

0.096

3.5

0.036

7.8

0.081

4.0

0.042

8.6

0.089

3.7

0038

8.1

0.084

4.0

0.042

8.6

0.089

4.0

0.042

8.6

0.089

GEORGIA

Atlanta

Brunswick

Macon

Savannah

Thomasville

HAWAII

Hawaiian Islands

(1)

•

2006 National Standard Pfiimhfn" Coi/e-llhistrnicJ

369

Table A.l RAINFALL RATES FOR CITIES, Continued

STATES AND CITIES

PRIMARY

STORM DRAINAGE

60-MIN DURATION

100-YR RETURN

IN/HR

GPM/SF

SECONDARY

STORM DRAINAGE

15-MIN DURATION

100-YR RETURN

IN/HR

GPM/SF

IDAHO

Boise
Idaho Falls
Lewiston
Twin Falls

1.0
1.2
1.0
1.1

0.010
0.012
0.010
0.011

2.3
3.2
2.9
2.3

0.024
0.033
0.030
0.024

ILLINOIS

Chicago
Hanisburg
Peoria
Springfield

2.7
3.1
2.9
3.0

0.028
0.032
0.030
0.031

6.3
6.9
6.6
6.6

0.065
0.072
0.069
0.069

INDIANA

Evansville
Indianapolis
Richmond
South Bend

3.0
2.8
2.7
2.7

0.031
0.029
0.028
0.028

6.9
6.3
6.3
6.0

0.072
0.065
0.065
0.062

IOWA

Council Bluffs
Davenport
Des Moines
Sioux City

3.7
3.0
3.4
3.6

0.038
0.031
0.035
0.037

8.1

7.2
7.8
7.8

0.084
0.075
0.081
0.081

KANSAS

Goodland
Salina
Topeka
Wichita

3.5
3.8
3.8
3.9

0.036
0.039
0.039
0.041

7.5
8.6
8.6
8.9

0.078
0.089
0.089
0.092

KENTUCKY

Bowling Green
Lexington
Louisville
Paducah

Cheboygan
Detroit
Grand Rapids
Kalamazoo
Traverse City

2.9
2.9
2.8
3.0

0.030
0.030
0.029
0.031

2.1

2.5
2.6

2.7
2.2

0.022
0.026
0.027
0.028
0.023

6.9
6.6
6.3
6.9

4.6
5.5
5.5
6.0
4.9

0.072
0.069
0.065
0.072

LOUISIANA

Monroe
New Orleans
Shreveporl

3.8

4.5
4.0

0.039
0.047
0.042

8.9
10.1
9.5

0.092
0.105
0.099

MAINE

Bangor
Kittery
Millinocket

2.2
2.4
2.0

0.023
0.025
0.021

4.9
5.8
4.3

0.051
0.060
0.045

MARYLAND

Baltimore
Frostburg
Ocean City

3.6
2.9

3.7

0.037
0.030
0.038

8.6
6.6
8.6

0.089
0.069
0.089

MASSACHUSETTS

Adams
Boston
Springfield

2.6
2.7
2.7

0.027
0.028
0.028

6.0
6.3
6.3

0.062
0.065
0.065

MICHIGAN

0.048
0.057
0.057
0.062
0.051

MINNESOTA

Duluth
Grand Forks
Minneapolis
Worthineton

2.6
2.5
3.0
3.4

0.027
0.026
0.031
0.035

6.0
6.0
6.9

7.5

0.062
0.062
0.072
0.078

MISSISSIPPI

Biloxi

Columbus

Jackson

4.5
3.5
3.8

0.047
0.036
0.039

10.1
7.8
8.6

0.105
0.081
0.089

370

2006 Nationiil Standard Plumbing Cutlr-Illustroied

•

Table A.l RAINFALL RATES FOR CITIES, Continued

STATES AND CITIES

MISSOURI

Independence
Jefferson City
St. Louis
Springfield

MONTANA

Billings
Glendive
Great Falls
Missoula

•

Binghamton
Buffalo
New York
Schenectady
Syracuse

NORTH CAROLINA

Ashville
Charlotte
Raleigh
Wilmington

NORTH DAKOTA

Bismarck

Fargo

Minot

OHIO

Cincinnati

Cleveland

Columbus

Toledo

Youngstown

OKLAHOMA

Boise City
Muskogee
Oklahoma City

OREGON

Medford
Portland
Ontario

PRIMARY

STORM DRAINAGE

60-MIN DURATION

100-VR RETURN

IN/HR

GPM/SF

3.7
3.4
3.2
3.7

0.038
0.035
0.033
0.038

2.5
1.8
1.3

0.019
0.026
0.019
0.014

2.4
2.3
3.1
2.5
2.4

0.025
0.024
0.032
0.026
0.025

3.2
3.4
4.0
4.4

0.033
0.035
0.042
0.046

2.7
2.9
2.6

0.028
0.030
0.027

3.4
4.0
4.1

0.035
0.042
0.043

SECONDARY

STORM DRAINAGE

15-M1N DURATION

100-YR RETURN

8.4
7.8
7.2
8.1

3.7
5.8
3.7
2.9

5.5
5.2
6.9
5.8
5.2

7.2
8.1
8.9
9.5

6.3
6.6
5.8

7.8
9.2
9.2

GPM/SF

0.87
0.081
0.075
0.084

0.038
0.060
0.038
0.030

NEBRASKA

Omaha
North Platte
Scotts Bluff

3.6
3.5

2.8

0.037
0.036
0.029

8.1
7.5
6.0

0.084
0.078
0.062

NEVADA

Las Vegas

Reno

Winnemucca

1.5
1.2
1.0

0.016
0.012
0.010

3.5
2.9
2.3

0.036
0.030
0.024

NEW HAMPSHIRE

Berlin
Manchester

2.2
2.5

0.023
0.026

5.2
5.8

0.054
0.060

NEW JERSEY

Atlantic City

Paterson

Trenton

3.4
3.0
3.2

0.035
0.031
0.033

8.1
6.9

7.2

0.084
0.072
0.075

NEW MEXICO

Albuquerque

Carlsbad

Gallup

2.0
2.6
2.1

0.021
0.027
0.022

4.0
6.0
4.9

0.042
0.062
0.051

NEW YORK

0.057
0.054
0.072
0.060
0.054

0.075
0.084
0.092
0.099

0.065
0.069
0.060

2.8

0.029

6.3

0.065

2.4

0.025

5.5

0.057

2.7

0.028

6.3

0.065

2.6

0.027

5.8

0.060

2.4

0.025

5.8

0.060

0.081
0.096
0.096

0.014

3.2

0.033

0.014

3.2

0.033

0.010

2.3

0.024

2006 National Standard Plumbing Code-Hlusniilcd

371

Table A.l RAINFALL RATES FOR CITIES, Continued

STATES AND CITIES

PRIMARY

STORM DRAINAGE

60-MIN DURATION

100-YR RETURN

1N/HR

GPM/SF

SECONDARY

STORM DRAINAGE

15-MIN DURATION

1 00-YR RETURN

1N/HR

GPM/SF

PENNSYLVANIA

Erie

Harrisburg

Philadelphia

Pittsburg

Scranton

Corpus Christi

Dallas

El Paso

Houston

Lubbock

San Antonio

Charlottesville
Richmond
Roanoke
Norfolk

La Cross
Green Bay
Milwaukee
Wausau

2.4
2.9
3.2
2.5
2.8

0.025
0.030
0.033
0.026
0.029

2.9
2.5
2.7
2.5

0.030
0.026
0.028
0.026

5.5
6.6
7.2
5.8
6.0

6.9
5.8
6.3
5.8

0.057
0.069
0.075
0.060
0.062

RHODE ISLAND

Newport
Providence

3.0
2.9

0.031
0.030

7.2
6.9

0.075
0.072

SOUTH CAROLINA

Charleston

Columbia

Greenville

4.1
3.5
3.3

0.043
0.036
0.034

7.8
8.4
9.2

0.081
0.087
0.096

SOUTH DAKOTA

Lemmon
Rapid City
Sioux Falls

2.7
2.7
3.4

0.028
0.028
0.035

6.3
6.3

7.5

0.065
0.065
0.078

TENNESSEE

Knoxville

Memphis

Nashville

3.1
3.5
3.0

0.032
0.036
0.031

7.2
7.5
7.2

0.075
0.078
0.075

TEXAS

4.6

0.048

10.7

0.11)

4.2

0.044

9.5

0.099

2.0

0.021

4.9

0.051

4.6

0.048

10.7

0.111

3.3

0.034

7.5

0.078

4.4

0.046

9.8

0.102

UTAH

Bluff

2.0

0.021

4.3

0.045

Cedar City

1.5

0.016

3.5

0.036

Salt Lake City

1.3

0.014

2.6

0.027

VERMONT

Bennington

2.5

0.026

5.8

0.060

Burlington

2.3

0.024

5.2

0.054

Rutland

2.4

0.025

5.5

0.057

VIRGINIA

3.4

0.035

7.8

0.081

4.0

0.042

8.9

0.092

3.3

0.034

7.8

0.081

4.0

0.042

9.5

0.099

WASHINGTON

Seattle
Spokane
Walla Walla

1.0
1.0

1.0

0.010
0.010
0.010

2.3
2.6
2.9

0.024
0.027
0.030

WESTV1RG1N1A

Charleston

Marlinsburg

Morgantown

2.9
3.0
2.7

0.030
0.031
0.028

6.6

7.2
6.3

0.069
0.075
0.065

WISCONSIN

0.072

0.060

0.065

0.60

WYOMING

Casper
Cheyenne
Evasion
Rock Springs

1.9

2.5
1.3
1.4

0.020
0.026
0.014
0.015

4.3
5.5
2.9
3.5

0.045
0.057
0.030
0.036

I Rainfall tales in Hawaiian Islands van' from 1.5 in/hi lo X in/hi depending.' on localion and elevation. Consult local data

372

200b National Standard Plumbing Code-Illustrated

Table A.5

DISCHARGE FROM RECTANGULAR SCUPPERS

GALLONS PER MINUTE

WATER HEAD

WIDTH OF SCUPPER

-(Inches)

(Inches)

0.5

107

1.5

130

163

196

149

200

251

302

2.5

136

207

278

349

420

177

271

364

458

551

3.5

339

457

575

693

412

556

700

844

NOTES:

1 . Table A.5 is based on discharge over a rectangular weir with end contractions.

2. Head is depth of water above bottom of scupper opening.

3. Height of scupper opening should be 2 times the design head.

4. Coordinate the allowable head of water with the structural design of the roof.

•

2006 National Standard Plumbing Code-Illustrated

373

Blank Page

374 2U0b Naliondl Slumlord Plumbing Cude-Ulustraled

Appendix B

Sizing the Building Water

Supply System

B.l

B.2

B.2.1

B.2.2

B.2.3

B.2.4

B.2.5

B.2.6

B.2. 7

B.2. 8

B.2.9

B.3

B.4
B.5
B.5. 1
B.5. 2

B.5.3

B.5.4

B.5.5

B.6

B.6.1

B.6.2

B.6.3

B.7

B.7.1

B.7.2

B.7. 3

B.7.4

GENERAL ,,,, 377

PRELIMINARY INFORMATION . 377

Genera] ,....,.. 377

Materials for System 377

Characteristics of the Water Supply 377

Location and Size of Water Supply Source 378

Developed Length of System 378

Pressure Data Relative to Source of Supply 378

Elevations 378

Minimum Pressure Required at Highest Water Outlets ; ... 378

Provision of Necessary Information on Plans 378

DEMAND AT INDIVIDUAL OUTLETS 379

Table B.3 MAXIMUM DEMAND AT INDIVIDUAL WATER OUTLETS 379

RESERVED , ,,..., 379

ESTIMATING DEMAND 380

Standard Method , 380

Water Supply Fixture Units (WSFU) Assigned to Fixtures 380

Table B.5. 2 WATER SUPPLY FIXTURE UNITS (WSFU) AND

MINIMUM FIXTURE BRANCH PIPE SIZES 381

Table B.5.3 WATER SUPPLY FIXTURE UNITS FOR FIXTURE GROUPS 383

Table B.5.3 BATHROOM GROUPS HAVING 1.6 GPF WATER CLOSETS OTHER

THAN THE FLUSHOMETER VALAVE TYPE. 382

Demand (GPM) Corresponding to Fixture Load (WSFU) 383

Table B.5.4 TABLE FOR ESTIMATING DEMAND 384

Total Demand Including Continuous Flow 383

LIMITATION OF VELOCITY 384

Consideration of Velocity in Design 384

Good Engineering Practice 385

Manufacturers' Recommendations for Avoiding Erosion/Corrosion 385

SIMPLIFIED METHOD FOR SIZING SYSTEMS IN RELATIVELY LOW BUILDINGS 385

Application 385

Simplified Method Based on Velocity Limitations 386

Sizing Tables Based on Velocity- Limitations 386

Table B.7. 3. A - GALVANIZED STEEL PIPE - STD WT , 387

Table B.7.3.B - TYPE K COPPER TUBE 387

Table B.7.3.C - TYPE L COPPER TUBE 388

Table B.7.3.D - TYPE M COPPER TUBE 388

Table B.7.3.E - CPVC, PVC, ABS PLASTIC PIPE - SCHEDULE 40 389

Table B.7.3.F - CPVC PVC, ABS PLASTIC PIPE - SCHEDULE 80 389

Table B.7.3.G - CPVC PLASTIC TUBING (Copper Tube Size - SDR I 1 389

Step-by-Step Procedure of Simplified Sizing Method 386

•

2006 National Standard P/unihina CaJe-llhutinited

375

B.8 ILLUSTRATION OF SIMPLIFIED SIZING METHOD APPLICATION 390

B.8.1 Example 390

Figure B.8.1 WATER PIPING ISOMETRIC (NO SCALE) 391

DATA for FIGURE B.8.1 - WATER SUPPLY FIXTURE UNITS (WSFU) 392

B.8.2 Solution 390

B.8. 3 Supplementary Check of Friction Loss in Main Lines and Risers 395

Figure B.8.2 WATER PIPING ISOMETRIC (NO SCALE) 393

Table B.8.2 PRESSURE DROPS IN THE BASIC DESIGN CIRCUIT rN FIGURE B.8.2 394

B.8.4 Application to Systems in High Buildings 395

B.9 LIMITATION OF FRICTION ...395

B.9.1 Basic Criterion .395

B.9. 2 Maximum Permissible Friction Loss ,. 395

B.9.3 Basic Design Circuit 396

B.9.4 Friction Loss in Equipment 396

B.9.5 Estimating Pressure Loss in Displacement Type Cold-Water Meters 396

B.9. 6 Uniform Pipe Friction Loss 397

B.9.7 Equivalent Length of Piping 397

Table B.9.7A ALLOWANCE IN EQUIVALENT LENGTH OF
PIPE FOR FRICTION LOSS IN VALVES AND

THREADED FITTINGS (NPT Sizes) ,..,- 397

Table B.9.7B ALLOWANCE IN EQUIVALENT LENGTH OF
TUBE FOR FRICTION LOSS IN VALVES AND

FITTINGS (Copper Tubing) 398

Table B.9.7. C EQUIVALENT LENGTH OF PIPE FOR FRICTION LOSS

IN SCHEDULE 40 CPVC FITTINGS ., 398

Table B.9.7.D EQUIVALENT LENGTH OF PIPE FOR FRICTION LOSS

IN SCHEDULE- 80 CPVC FITTINGS 398

Table B.9.7.E EQUIVALENT LENGTH OF PIPE FOR FRICTION LOSS

IN CPVC SDR 1 1 CTS TUBING FITTINGS 398

B.9. 8 Determination of Flow Rates Corresponding to Uniform Pipe Friction Loss 397

B.9. 8.1 Flow vs. Pressure Drop - Galvanized Steel ASTM A53 400

B.9. 8. 2 Flow vs. Pressure Drop- Type K Copper Tube 401

B.9. 8. 3 Flow vs. Pressure Drop - Type L Copper Tube 402

B.9. 8.4 Flow vs. Pressure Drop - Type M Copper Tube 403

B.9. 8. 5 Flow vs. Pressure Drop - CPVC/PVC/ABS Sched 40 Pipe 404

B .9.8.6 Flow vs. Pressure Drop - CPVC/PVC/ABS Sched 80 Pipe 405

B.9. 8. 7 Flow vs. Pressure Drop - CPVC Tubing (Copper Tube Size SDR 1 I ) 406

BIO DETAILED SIZING METHOD FOR SYSTEMS IN BUILDINGS

OF ANY HEIGHT 399

B.N ILLUSTRATION OF DETAILED SIZING METHOD APPLICATION 407

B.I 1.1 Example 407

B.I 1.2 Solution 407

Table B.l 1.2 TYPE L COPPER TUBING FOR "FAIRLY SMOOTH" CONDITION 408

B.I2 MANIFOLD TYPE PARALLEL WATER DISTRIBUTION SYSTEMS 408

B.l 2. 1 Manifolds 408

Table B.l 2.1 MANIFOLD SIZING 409

B.l 2.2 Distribution Lines 409

376 200b Nutional Standard Plumbing Coilc-llluxrrou-d

B.l GENERAL

Note that there are two questions regarding water supply to a building: first, total consumption of water (hot or cold
or both) over a period of time, or second, peak flow at any instant of time. This appendix considers only the second
question.

Proper design of the water-distributing system in a building is necessary to avoid excessive installed cost and in
order that the various fixtures may function properly under normal conditions. The instantaneous flow of either hot
or cold water in any building is variable, depending on the type of structure, usage, occupancy, and time of day.
The correct design results in piping, water heating, and storage facilities of sufficient capacity to meet the probable
peak demand without wasteful excess in either piping or maintenance cost.
For additional information on this subject, the reader is referred to:

National Bureau of Standards Building Materials and Structures Report BMS 65 (1940), Methods of Estimating
Loads in Plumbing Systems, by R. B. Hunter

National Bureau of Standards Building Materials and Structures Report BMS 79 (1941), Water-Distributing
Systems for Buildings, by R. B. Hunter

New York State Division of Housing and Community Renewal Building Codes Bureau Technical Report No. 1,
( 1 964), A Simplified Method for Checking Sizes of Building Water Supply Systems, by Louis S. Nielsen.

B.2 PRELIMINARY INFORMATION

B.2.1 General

The information necessary for sizing the building water supply system is described in B.2. 2 through B.2. 9.
Correct sizing is contingent upon accuracy and reliability of the information applied. Thus, such information
should be obtained from responsible parties and appropriate local authorities recognized as sources of the
necessary information.

B.2. 2 Materials for System

Determine what kind or kinds of piping materials are to be installed in the system. This is a matter of selection
by the owner of the building or his authorized representative, who may be the architect, engineer, or contrac-
tor, as the case may be.

B.2.3 Characteristics of the Water Supply

The corrosivity and the scale-forming tendency of a given water supply with respect to various kinds of piping
materials is information that most officials, architects, engineers, and contractors in a water district normally
have at their fingertips, as a result of years of experience. For anyone without such experience and knowl-
edge, significant characteristics of the water supply, such as its pH value, CO, content, dissolved air content,
carbonate hardness, Langefier Index, and Ryznar Index, may be applied to indicate its corrosivity and
scale-forming tendency. The most appropriate source of such information is the local water authority having
jurisdiction over the system supplying the water, or over the wells from which water is pumped from the
underground water table.

2006 National SranJanf Pliouhins CoJr.-Ilhtsiniietl 377

B.2.4 Location and Size of Water Supply Source

Location and size of the public water main, where available, should be obtained from the local water author-
ity. Where a private water supply source, such as a private well system, is to be used, the location and size as
designed for the premises should be determined.

B.2.5 Developed Length of System

Information should be obtained regarding the developed length of the piping run from the source of water
supply to the service control valve of the building (i.e., the developed length of the water service pipe as
shown on site plans). Also, determine the developed length of the piping run from the service control valve to
the highest and/or the most remote water outlet on the system. This may be established by measurement of
the piping run on the plans of the system.

B.2.6 Pressure Data Relative to Source of Supply

Maximum and minimum pressures available in the public main at all times should be obtained from the water
authority, as it is the best source of accurate and reliable information on this subject.

Where a private well water supply system is to be used, the maximum and minimum pressures at which it will
be adjusted to operate may be applied as appropriate in such cases.

B.2.7 Elevations

The relative elevations of the source of water supply and the highest water supply outlets to be supplied in the
buildingmust be determined. In the case of a public main, the elevation of the point where the water service
connection is to be made to the public main should be obtained from the local water authority. It has the most
authoritative record of elevations of the various parts of the public system, and such elevations are generally
referred to a datum as the reference level, usually related to curb levels established for streets.

Elevation of the curb level directly in front of the building should be obtained from building plans, as such
information is required to be shown on the building site plans. Elevations of each floor on which fixtures are to
be supplied also may be determined from the building plans.

B 2.8 Minimum Pressure Required at Water Outlets

Information regarding the minimum flowing pressure required at water outlets for adequate, normal flow
conditions consistent with satisfactory fixture usage and equipment function may be deemed to be as follows:
1 5 psig flowing for all water supply outlets at common plumbing fixtures, except 20 psig for flushometer
valves on siphon jet water closets and 25 psig for flushometer valves for blowout water closets and blowout
urinals. Flushometer tank (pressure assisted) water closets require a minimum of 25 psig static pressure. For
other types of water supplied equipment, the minimum flow pressure required should be obtained from the
manufacturer.

B.2.9 Provision of Necessary Information on Plans

The basis for designing sizes of water supply piping should be provided on plans of the water supply system
when submitted to plumbing plan examiners for proposed installations. Provision of such information permits
the examiner to quickly and efficiently check the adequacy of sizes proposed for the various parts of the
building water supply system.

378 2006 National Standard Plumbing Code-H'lustraa-ii

•

B.3 DEMAND AT INDIVIDUAL OUTLETS

Maximum possible flow rates at individual fixtures and water outlets have become generally accepted as industry
practice, which have since become maximum rates set by law. Recognized flow rates at individual water outlets
for various types of typical plumbing fixtures and hose connections are given in Table B.3.

For older faucets, if the applied pressure is more than twice the minimum pressure required for satisfactory water
supply conditions, an excessively high discharge rate may occur. Such rates may cause the actual flow in the
piping to exceed greatly the estimated probable peak demand rate determined in accordance with the standard
method discussed in Section B.5. Such excessive velocity of flow and friction loss in piping may adversely affect
performance and durability of the system.

More recent faucets, however, are equipped with flow limiting devices that control the discharge rate at a nearly
constant value over a large range of pressures.

Where necessary, it is recommended that means to control the rate of supply should be provided in the fixture
supply pipe (or otherwise) wherever the available pressure at an outlet is more than twice the minimum pressure
required for satisfactory supply. For this puipose, individual regulating valves, variable orifice flow control devices,
or fixed orifices may be provided. They should be designed or adjusted to control the rate of supply to be equal to
or less than the maximum rates set by law.

Table B.3
MAXIMUM DEMAND AT INDIVIDUAL WATER OUTLETS

Type of Outlet Maximum Demand, (gpm)

Metering lavatory faucet 0.25 gal/cycle

Self-closing lavatory faucet 0.5

Drinking fountain jet 0.75

Ordinary lavatory faucet 2.5

Shower head, 1/2" 2.5

Laundry faucet, 1/2" 2.5

Ballcock in water closet flush tank 3.0

Dishwashing machine (domestic ) 4.0

Laundry machine (8 or 16 lbs.) 4.0

Sink faucet, 3/8" or 1/2" 4.5

Bath faucet, 1/2" 5.0

Hose bibb or sillcock (1/2") 5.0

Sink faucet, 3/4" 6.0

I /2" flush valve ( 1 5 psi flow pressure ) 1 5.0

1 " flush valve (1 5 psi flow pressure) 27.0

1" flush valve (25 psi flow pressure) 35.0

B.4 RESERVED

2006 National Standard Plumbing Code-Ittitsi-hiied 379

B.5 ESTIMATING DEMAND

B.5.1 Standard Method

A standard method for estimating the maximum probable demand in building water supply systems has
evolved and become recognized as generally acceptable. In 1923, the fixture unit method of weighting fixtures
in accordance with their load-producing effects was proposed by Roy B. Hunter, of the National Bureau of
Standards. After studying application of the method in the design of federal buildings over a period of years,
the method was revised by Hunter in 1940 ] , and then recommended for general application. With appropriate
modifications recently made for modern fixtures, the method fills the need for a reliable, rational way to
estimate probable peak demand in water supply systems for all types of building occupancy.

Note that the concept of maximum probable demand is one of probability. We are saying, in effect, that
the calculated flow rate at any point in a water piping system will not be exceeded more than, say, 0.1% of
the time. For most systems designed by the method described herein, the design flow rates are never
reached. Therefore, the method gives a conservative approach that still does not result in wasteful oversizing.

B.5.2 Water Supply Fixture Units (WSFU) Assigned to Fixtures

Individual fixture branch piping should be sized to provide the flow rates listed in Table B.3 for the particular
fixture. Minimum fixture branch pipe sizes are listed in Table B.5.2.

Peak demand in building water supply systems serving multiple fixtures cannot be determined exactly. The
demand imposed on a system by intermittently used fixtures is related to the number, type, time between uses,
and probable number of simultaneous uses of the fixtures installed in the building. In the standard method,
fixtures using water intermittently under several conditions of service are assigned specific load values in
terms of water supply fixture units. The water supply fixture unit (WSFU) is a factor so chosen that the load-
producing effects of different kinds of fixtures under their conditions of service can be expressed approxi-
mately as multiples of that factor. WSFUs for two or more fixtures can then be added to determine their
combined effect on the water supply system.

Values assigned to different kinds of fixtures and different types of occupancies are shown in Table B.5.2.
The total WSFUs represent the fixture's demand on the domestic water service to the building. For fixtures
having both hot and cold water supplies, the values for separate hot and cold water demands are taken as
being three-quarters (3/4) of the total value assigned to the fixture in each case, rounded to the nearest tenth
of a W 7 SFU. As an example, since the value assigned to a kitchen sink in an individual dwelling unit is 1 .5
WSFU, the separate demands on the hot and cold water piping thereto are taken as being 1.1 WSFU.

Another consideration, added in 1994, is the nature of the application of the plumbing fixture. Table B.5.2
includes columns for Individual Dwelling Units, More Than 3 Dwelling Units, Other Than Dwelling Units, and
Heavy-Use Assembly. The concept behind these added classifications is that the maximum probable demand
created by plumbing fixtures varies depending on the type of occupancy in which they are installed.

1. National Bureau of Standard* Building Materials and Structure* Report BMS 6, Methods of Estimating Loads in Plumbing Systems, by R. B. Hunter

380 2006 National Stuiuluri! Plumbing t'oife-lliusrmieJ

•

Table B.5.2
WATER SUPPLY FIXTURE UNITS (WSFU) 1 AND MINIMUM FIXTURE BRANCH PIPE SIZE FOR INDIVIDUAL FIXTURES

NOTES:

1 . The "total" WSFU values for fixtures represent their load on the water service. The separate cold water and hot water supply fixture units for fixtures having both hot and
cold connections are each taken as V* of the listed total value for the individual fixture.

2. The fixture branch pipe sizes in Table B.5.2 are the minimum allowable. Larger sizes may be necessary if the water supply pressure at the fixture will be too low due to the
available building supply pressure or the length of the fixture branch and other pressure losses in the distribution system.

3. The WSFU values for 3,5 GPF water closets also apply to water closets having flushing volumes greater than 3.5 gallons.

4. Gravity tank water closets include the pump assisted and vacuum assisted types.

Table B.5.3-BATHROOM GROUPS HAVING 1.6 GPF WATER CLOSETS OTHER THAN THE FLUSHOMETER

VALAVE TYPE

Totals In

Individual

Dwelling Units

Each Group

In 3 or More

Dwelling Units

BATHROOM GROUPS HAVING 1.6 GPF WATER
CLOSETS 2 OTHER THAN THE FLUSHOMETER
VALVE TYPE

Total
WSFU

Cold
WSFU

Hot
WSFU

Total
WSFU

Cold
WSFU

Hot

WSFU

Half-Bath or Powder Room

3.5

3.3

0.8

2.5

0.4

1 Bathroom Group

5.0

3.8

3.5

3.0

1-1/2 Bathrooms

6.0

4.5

2 Bathrooms

7.0

2-1/2 Bathrooms

8.0

3 Bathrooms

9.0

'' n * ***

Each Additional Vi Bath

0.5

[ i L , | "" A "

Each Additional Bathroom Group

1.0

V 1 "*' -*»«*-"""*i'-™

Cold
WSFU

, .

BATHROOM GROUPS HAVING 3.5 GPF 1
GRAVITY-TANK WATER CLOSETS

Total
WSFU

Cold
WSFU

Hot
WSFU

Total
WSFU

Hot
WSFU

Half-Bath or Powder Room

4.0

3.8

0.8

3.0

0.4

1 Bathroom Group

6.0

6.Q

3.8

5.0

3,0

1-1/2 Bathrooms

8.0

8,0|

4.5

' . < ^» < ».
? .* "„ * f£> ■*»*

,i»~ ^ £*$$?

2 Bathrooms

10.0

7.0

-**.

j <****' v ■*. ■■ x

^J, * ^

2-1/2 Bathrooms

11.0

8.0

t > f ^«

i >n,

** \ <*.«£

3 Bathrooms

12.0

9.0

t s ft *t V

';;\;fivf|^f^

iJ^W^W,

Each Additional Vi Bath

0.5

4«f

\ ' "tm

Each Additional Bathroom Group

1.0

' _v*vl;r.

,V f iJH*

OTHER GROUPS OF FIXTURES

Total

WSFU

Cold
WSFU

Hot

WSFU

Total
WSFU

Cold
WSFU

Hot
WSFU

Bath Group with 1.6 GPF Flushometer Vaive

6.0

3.8

4.0

3.0

Bath Group with 3.5 GPF' Flushometer Valve

8.0

3.8

6.0

3.0

Kitchen Group (Sink and Dishwasher)

2.0

1.1

2.0

1.5

0.8

1.5

Laundry Group (Sink and Clothes Washer)

5.0

4.5

3.0

2.6

NOTES: I. The "Total WSFU" values for fixture groups represent their load on the water service. The separate cold and hot water supply fixture units for the group are each taken

as % of the WSFU values for the individual fixtures in the group according to Table B.5.2, but not greater than the "Total WSFU" for the group in Table B.5.3, except that
the hot WSFU for groups having 3.5 GPF water closets are the same as those having 1.6 GPF water closets.

2. The WSFU values for 1.6 GPF water closets other than the flushometer valve type apply to gravity tanks, flushometer tanks (pressure assisted), pump assisted tanks,
and vacuum assisted tanks.

3. The WSFU values for 3,5 GPF water closets also apply to water closets having flushing volumes greater than 3.5 gallons.

•

B.5.3 Water Supply Fixture Units for Fixture Groups

Table B.5.3 lists water supply fixture unit values for typical groups of fixtures in bathrooms, kitchens, and
laundries in dwelling units. There is more diversity in the use of the fixtures in these groups than is reflected
by WSFU values for the individual fixtures. The "Total WSFU" represents the demand that the group places
on the domestic water service to the building. The separate cold and hot WSFU's for the group are each
taken as 3 A of the WSFU values for the individual fixtures in the group according to Table B.5.3, but not
greater than the "Total WSFU" for the group. An exception is that the hot WSFU values for bathroom groups
having 3.5 GPF (or greater) water closets are the same as those having 1 .6 GPF water closets, since the hot
WSFU's are not affected by the demand of the water closet.

B.5.4 Demand (GPM) Corresponding to Fixture Load (WSFU)

To determine the maximum probable demand in gallons per minute corresponding to any given load in water
supply fixture units, reference should be made to Table B.5.4, in which the values have been arranged for
convenient conversion of maximum probable demand from terms of water supply fixture units of load to
gallons per minute of flow. Intermediate values may be interpolated for loads between those shown in Table
B.5.4.

Note in the table that the maximum probable demand corresponding to a given number of water supply fixture
units is generally much higher for a system in which water closets are flushed by means of direct-supply
flushometer valves than for a system in which the water closets are flushed by other types of flushing de-
vices. The difference in maximum probable demand between the two systems diminishes as the total number
of fixture units of load rises. At 1 ,000 water supply fixture units, the maximum probable demand in both types
of systems is the same, 2 1 gpm.

Where a part of the system does not supply flushometer water closets, such as in the case with hot water
supply piping and some cold water supply branches, the maximum probable demand corresponding to a given
number of water supply fixture units may be determined from the values given for a system in which water
closets are flushed by flush tanks.

B.5.5 TotalDemand Including Continuous Flow

To estimate the maximum probable demand in gpm in any given water supply pipe that supplies outlets at
which demand is intermittent and also outlets at which demand is continuous, the demand for outlets that pose
continuous demand during peak periods should be calculated separately and added to the maximum probable
demand for plumbing fixtures used intermittently. Examples of outlets that impose continuous demand are
those for watering gardens, washing sidewalks, irrigating lawns, and for air conditioning or refrigeration
apparatus.

Note that some continuous-flow outlets may be controlled to be used only during iow-flow periods in the
system. Such time-controlled loads should not be added to the maximum probable demand for intermittently
used fixtures, since they will not occur at the same times. In such cases, it will be necessary to consider both
situations and size the piping for the worse case.

2006 National SumJunl Plumbing Cotle-lllusnaicd 383

Table B.5.4
TABLE FOR CONVERTING DEMAND IN WSFU TO GPM 1

WSFU

GPM
FlushTanks 2

GPM
FlushValves 3

WSFU

GPM
FlushTanks 2

GPM
FlushValves 3

120

140

4.5

160

180

200

225

7.5

250

100

300

110

8.5

400

105

125

500

125

140

29.5

750

170

175

10.5

1000

210

1250

240

1500

270

12.5

1750

300

33.5

2000

325

13.5

2500

380

3000

435

4000

525

5000

600

6000

650

7000

700

8000

730

62 1 9000

760

100

68 § 10,000

790

NOTES: 1 . This table converts water supply demands in water supply fixture units (WSFU) to required water flow in gallons per minute
(GPM) for the purpose of pipe sizing.
2. This column applies to the following portions of piping systems:
(a). Hot water piping;

(b). Cold water piping that serves no water closets; and
(c). Cold water piping that serves water closets other than flush valve type.
3 This column applies to portions of piping systems where the water closets are the flush valve type.

B.6 LIMITATION OF VELOCITY

B.6.1 Consideration of Velocity in Design

Velocity of flow through water supply piping during periods of peak demand js an important factor that must be
considered in the design of building water supply systems. Limitation of water velocity should be observed in order
to avoid objectionable noise effects in systems, shock damage to piping, equipment, tanks, coils, and joints, and
accelerated deterioration and eventual failure of piping from corrosion. (Also see Section 10.14.1)

384

100b Kali unit I Standard Plumbing Code-UlusiraieJ

B.6.2 GoodEngineeringPractice

In accordance with good engineering practice, it is recommended generally that maximum velocity at maxi-
mum probable demand in supply piping be limited to 8 fps. This is deemed essential in order to avoid such
objectionable effects as the production of whistling line noise, the occurrence of cavitation, and associated
excessive noise in fittings and valves.

Note that this velocity is too great for systems where the flow is continuous, as in the case of recirculated hot
water piping. The continuous flow rate for hot water with modest chemical content should be limited to not
more than 2 fps for such continuous systems. That is, verify that the flow rate in the system as a result of the
circulation pump only does not exceed 2 fps at any point.

It is also recommended that maximum velocity be limited to 4 fps in water supply piping that supply a
quick-closing device, such as a solenoid valve, pneumatic valve, or a quick-closing valve or faucet of the self-
closing, push-pull, push-button, or other similar type. This limitation is necessary in order to avoid excessive
and damaging shock pressures in the piping and equipment when flow is suddenly shut off. Plumbing equip-
ment and systems are not designed to withstand the very high shock pressures that may occur as the result of
sudden cessation of high velocity flow in piping. (Also see Section 10.14.1)

B.6.3 Manufacturers' Recommendations for Avoiding Erosion/Corrosion

Velocity limits recommended by pipe manufacturers to avoid accelerated deterioration of their piping materi-
als due to erosion/corrosion should be observed. Recent research studies have shown that turbulence accom-
panying even relatively low flow velocities is an important factor in causing erosion/corrosion, and that this is
especially likely to occur where the water supply has a high carbon dioxide content (i.e., in excess of 10 ppm),
and where it has been softened to zero hardness. Another important factor is elevated water temperature
(i.e., in excess of 1 10°F).

To control erosion/corrosion effects in copper water tube, and copper and brass pipe, pipe manufacturers'
recommendations are as follows:

(1) Where the water supply has a pH value higher than 6.9 and a positive scale-forming tendency, such as
may be shown by a positive Langelier Index, peak velocity should be limited to 8 fps;

(2) Where the water supply has a pH value lower than 6.9 and may be classified as aggressively corro-
sive, or where the water supply has been softened to zero hardness by passage through a water softener,
peak velocity should be limited to 4 fps; and

(3) The velocity in copper rube conveying hot water at up to 140°F should be limited to 5 fps because of
the accelerated corrosion rate with hot water. Velocities should be limited to 2 - 3 fps for temperatures
above 140°F.

Note that the above values apply to velocities at maximum probable demand. For continous flow circulating
systems, do not exceed 2 fps flow rate for the flow produced by the circulator.

B.7 SIMPLIFIED METHOD FOR SIZING SYSTEMS IN
RELATIVELY LOW BUILDINGS

B.7.1 Application

A simplified method for sizing building water supply systems in accordance with the maximum probable
demand load, in terms of water supply fixture units, has been found to constitute a complete and proper
method for adequately sizing the water supply systems of a specific category of buildings. In this category are

2006 National Standard Plumbing Code-Ilhistiottd 385

all buildings supplied from a source at which the minimum available water pressure is adequate for supplying
the highest and most remote fixtures satisfactorily during peak demand. Included are almost all one- and
two-family dwellings, most multiple dwellings up to at least three stories in height, and a considerable portion
of commercial and industrial buildings of limited height and area, when supplied from a source at which the
minimum available pressure is not less than 50 psi. Under such conditions, the available pressure generally is
more than enough for overcoming static head and ordinary pipe friction losses, so that pipe friction is not an
additional factor to consider in sizing.

B.7.2 Simplified Method Based on Velocity Limitations

This method is based solely on the application of velocity limitations that are:

( 1 ) Recognized as good engineering practice; and

(2) Authoritative recommendations issued by manufacturers of piping materials regarding proper use of
their products in order to achieve durable performance and avoid failure in service, especially in water areas
where the supply is aggressively corrosive. These limitations have been detailed in Section B.6. (Also see
Section 10.14.1.)

B.7.3 Sizing Tables Based on Velocity Limitations

Tables B.7.3.A through G provide a means of sizing water supply piping on the basis of flow velocities ranging
from 4 fps to 8 fps. The velocity in copper water tube for hot water up to MOT should not exceed 5 fps. The
water flow rates, flow velocities, and pressure loss rates are based on Tables B.9.8.1 through B.9.8.7 for the
various piping materials. The allowable water supply fixture unit (WSFU) fixture loadings are based on Table
B.5.4.

The pressure loss data in the B.7.3 tables is based on friction for straight pipe and tube and does not include
allowances for fittings, valves, and appurtenances. The equivalent length of the piping can be determined by
adding the equivalent length of fittings and valves in Tables B.9.7.A, B, C, D, and E. If the exact layout of the
piping systems cannot be determined, allowances for fittings and valves range up to 50% of the pipe length for
smooth bore piping such as copper and solvent cement joint plastic piping and up to 75% of the pipe length for
steel and plastic piping with threaded joints.

In Tables B.7.3.A through B.7.3 .G, the columns headed "WSFU (tanks)" apply to piping that serves water closets
having gravity or pressure-type flush tanks and no fixtures that are flushed by flushometer valves. The columns
headed "WSFU (valves)" apply to piping that serves fixtures that are flushed by flushometer valves.

B.7.4 Step-by-Step Procedure of Simplified Sizing Method

For sizing systems in relatively low buildings, the simplified sizing method consists of the following seven
steps:

1 . Obtain all information necessary for sizing the system. Such information should be obtained from
responsible parties and appropriate local authorities recognized as sources of the necessary information. (See
Section B.2.)

2. Provide a schematic elevation of the complete water supply system. Show all piping connections in
proper sequence and all fixture supplies. Identity all fixtures and risers by means of appropriate letters,
numbers, or combinations thereof. Identify all piping conveying water at a temperature above 150°F, and all
branch piping to such water outlets as solenoid valves, pneumatic valves, or quick-closing valves or faucets.
Provide on the schematic elevation all the necessary information obtained in Step I, (See Section B.2.9.)

3. Mark on the schematic elevation, for each section of the complete system, the hot and cold water loads
conveyed thereby in terms of water supply fixture units in accordance with Table B.5.2.

386 2006 National Standard Plumbing Coik-lIlustrareJ

Table B.7.3.A GALVANIZED STEEL PIPE - STD WT
WATER FLOW VELOCITY

PIPE
SIZE

4FPS

8 FPS

PIPE
SIZE

WSFU
(tanks)

WSFU
(valves)

FLOW
GMP

psi/lOOfi

WSFU
(tanks)

WSFU
(valves)

FLOW
GMP

psi/ 100ft

1/2"

3.8

7.6

7,6

27.3

1/2"

3/4"

6.6

5.5

13.3

19.7

3/4"

10.8

4.1

21.5

14.9

1-1/4"

18.6

3.0

37.3

10.8

1-1/4"

I- 1/2"

25.4

2.5

129

50.8

9.1

1-1/2"

41.8

1.9

293

163

83.7

6.8

2-1/2"

174

59.7

1.5

472

363

119.4

5.5

2-1/2"

336

207

92.2

1.2

840

817

184.4

4.3

687

634

158.7

0.9

1925

317.5

3.1

1329

249.4

0.7

3710

498.9

2.4

2320

360.2

0.5

7681

720.4

1.9

Table B.7.3.B - TYPE K COPPER TUBE
WATER FLOW VELOCITY

TUBE
SIZE

4 FPS

5 FPS

8 FPS

TUBE
SIZE

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

PD
psi/ 100ft

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

psi/ 100ft

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

psi/ 100ft

3/8"

1.6

8.4

2.0

12.7

3.2

30.4

3/8"

1/2"

2.7

6.)

3.4

9.3

5.4

22.1

1/2"

3/4"

5.4

4.)

6.8

6.2

10.9

14.8

3/4"

9.7

2.9

12.1

4.4

19.4

10.6

1-1/4"

15.2

2.3

19.0

3.4

30.4

8.1

1-1/4"

1-1/2"

21.5

1.8

26.9

2.8

43.0

6.7

1-1/2"

37.6

1.3

112

47.0

2.0

251

126

75.2

4.8

2-1/2"

165

58.1

1.0

238

115

72.6

1.6

456

341

116.1

3.7

2-1/2"

289

159

82.8

0.8

392

267

103.4

1.3

725

682

165.5

3.0

615

541

145.7

0.6

826

801

182.1

0.9

1678

291.4

2.2

1134

226.1

0.5

1605

282.6

0.7

3191

452.2

1.7

1978

322.8

0.4

2713

403.5

0.6

5910

645.5

1.4

•

2006 Naif (mat Standard PlumbiiHt Codc-llhisiraicd

387

Table B.7.3.C - TYPE L COPPER TUBE
WATER FLOW VELOCITY

TUBE
SIZE

4FPS

5FPS

8FPS

TUBE
SIZE

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

psi/IOOft

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

psi/ 100ft

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

psi/ 100ft

3/8"

1.8

7.8

2.3

11.7

3.6

28.0

3/8"

1/2"

2.9

5.9

3.6

8.9

5.8

21.3

1/2"

3/4"

6.0

3.9

7.5

5.8

12.1

13.9

3/4"

10.3

2.8

12.9

4.3

20.6

10.2

1-1/4"

15.7

2.2

19.5

3.3

31.3

8.0

1-1/4"

1-1/2"

22.2

1.8

27.7

2.7

101

44.4

6.5

1-1/2"

38.6

1.3

117

48.2

2.0

261

136

77.2

4.7

2-1/2"

173

59.5

1.0

247

120

74.4

1.5

470

360

119.0

3.7

2-1/2"

300

170

84.9

0.8

406

281

106.2

1.3

749

713

169.9

3.0

635

567

149.3

0.6

854

833

186.7

0.9

1739

298.7

2.2

1189

232.7

0.5

1674

290.9

0.7

3338

465.5

1.7

2087

334.6

0.4

2847

418.2

0.6

6382

669.1

1.4

Table B.7.3.D - TYPE M COPPER TUBE
WATER FLOW VELOCITY

TUBE
SIZE

4FPS

5FPS

8FPS

TUBE
SIZE

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

psi/ 100ft

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

psi/ 100ft

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

PD
psi/ 100ft

3/8"

2.0

7.3

2.5

11. 1

4.0

26.6

3/8"

1/2"

3.2

5.6

4.0

8.5

6.3

20.2

1/2"

3/4"

6.4

3.7

8.1

5.6

12.9

13.4

3/4"

10.9

2.7

13.6

4.1

21.8

9.9

1-1/4"

16.3

2.2

20.4

3.3

32.6

7.8

1-1/4"

1-1/2"

22.8

1.8

28.5

2.7

107

45.7

6.4

1-1/2"

39.5

1.3

122

49.4

2.0

270

144

79.1

4.7

2-1/2"

180

61.0

1.0

256

131

76.2

1.5

485

380

121.9

3.6

2-1/2"

310

180

87.0

0.8

419

294

108.8

1.2

775

743

174.0

3.0

648

583

151.6

0.6

872

854

189.5

0.9

1783

303.3

2.1

1215

235.8

0.5

1706

294.8

0.7

3407

471.6

1.7

2125

338.7

0.4

2894

423.4

0.6

6548

677.4

1.3

388

2006 National Slandtttd Plumhim; Cutic-lllu.siralfJ

•

Table B.7.3.E CPVC, PVC, ABS PLASTIC PIPE - SCHEDULE 40
WATER FLOW VELOCITY

PIPE
SIZE

4FPS

8FPS

PIPE
SIZE

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

PD
psi/100 ft

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

psi/lOOft

1/2"

3.6

5.2

7.3

18.7

1/2"

3/4"

6.4

3.7

12.9

13.4

3/4"

10.5

2.8

20.9

10.1

1-1/4"

18.2

2.0

36.4

7.3

1-1/4"

1-1/2"

24.9

1.7

124

49.7

6.1

1-1/2"

41.1

1.3

286

157

82.2

4.6

2-1/2"

168

58.5

1.0

460

347

117.1

3.7

2-1/2"

328

198

90.6

0.8

820

795

181.2

2.9

675

618

156.5

0.6

1881

313.1

2.1

1303

246.4

0.5

3642

492.8

1.6

2284

356.2

0.4

7413

712.4

1.3

Table B.7.3.F CPVC, PVC, ABS PLASTIC PIPE - SCHEDULE 80
WATER FLOW VELOCITY

PIPE
SIZE

4FPS

8 FPS

PIPE
SIZE

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

psi/ 100ft

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

PD
psi/ 100ft

1/2"

2.7

6.1

5.5

22.1

1/2"

3/4"

5.1

4.2

10.3

15.3

3/4"

8.6

3.1

17.2

11.3

1-1/4"

15.4

2.2

30.8

8.1

1-1/4"

1-1/2"

21.3

1.9

42.7

6.7

1-1/2"

35.8

1.4

233

112

71.7

4.9

2-1/2"

132

51.4

l/l

389

264

102.7

4.0

2-1/2"

277

149

80.3

0.9

698

648

160.7

3.1

585

503

140.4

0.6

1590

280.7

2.2

1105

222.6

0.5

3114

445.3

1.7

1942

319.2

0.4

5767

638.3

1.4

Table B.7.3.G CPVC PLASTIC TUBING (Copper Tube Size) - SDR 11
WATER FLOW VELOCITY

TUBE
SIZE
(CTS)

4 FPS

8 FPS

TUBE
SIZE
(CTS)

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

psi/ 100ft

WSFU
(tanks)

WSFU
(valves)

FLOW
GPM

PD
psi/ 100ft

1/2"

2.4

6.6

4.8

23.9

1/2"

3/4"

4.9

4.4

9.8

15.8

3/4"

8.1

3.3

16.2

11.8

1-1/4"

12.1

2.6

24.2

9.3

1-1/4"

1-1/2"

16.9

2.1

33.7

7.7

1-1/2"

28.9

1.6

164

57.8

5.6

2006 National Stan danl Plumbing Code-Illustrated

389

4. Mark on the schematic elevation, adjacent to all fixture unit notations, the demand in gallons per minute
corresponding to the various fixture unit loads in accordance with Table B.5.3.

5. Mark on the schematic elevation, for appropriate sections of the system, the demand in gallons per
minute for outlets at which demand is considered continuous, such as outlets for watering gardens, irrigating
lawns, air conditioning apparatus, refrigeration machines, and similar equipment using water at a relatively
continuous rate during peak demand periods. Add the continuous demand to the demand for intermittently
used fixtures, and show the total demand at those sections where both types of demand occur. (See Section
B.5.4.)

6. Size all individual fixture supply pipes to water outlets in accordance with the minimum sizes permitted
by regulations. Minimum fixture supply pipe sizes for typical plumbing fixtures are given in Table B.5.2.

7. Size all other parts of the water supply system in accordance with velocity limitations recognized as
good engineering practice, and with velocity limitations recommended by pipe manufacturers for avoiding
accelerated deterioration and failure of their products under various conditions of service. (Sizing tables
based on such velocity limitations and showing permissible loads in terms of water supply fixture units for
each size and kind of piping material have been provided and may be applied in this step.) (See Section B.6.)

B.8 ILLUSTRATION OF SIMPLIFIED SIZING METHOD APPLICATION

B.8.1 Example

A three-story, nine-family multiple dwelling fronts on a public street and is supplied by direct street pressure
from a public main in which the certified minimum pressure is 50 psi. The building has a full basement and
three above-grade stories, each of which is 10' in height from floor to floor. The first floor is T above the
curb level in front of the building. The public water main is located under the street: 5' out from and 4'
below the curb.

On each of the above-grade stories there are three dwelling units. Each dwelling unit has a sink and dish-
washer, tank-type water closet, lavatory, and bathtub/shower combination.

The basement contains two automatic clothes washing machines, two service sinks, and a restroom with a
flush-tank water closet and lavatory.

Two lawn faucets are installed, one on the front of the building and one in the rear.

Hot water is to be supplied from a central storage-tank water heater.

The water supply to the building will be metered at the water service entry point to the building.

An isometric drawing of the water piping layout is shown in Figure B.8. 1 .

B.8.2 Solution

1 . All information necessary to develop the design must be obtained from appropriate sources.

2. After the information is known, the isometric drawing (Figure B.8.1) is marked up with general water
supply information, and the mains, risers, and branches are suitably identified.

3. The water supply fixture unit loads are marked on the drawing next to each section of the system.
These values are obtained from Tables B.5.2 and B.5.3. Many designers use parentheses marks for WSFU
to distinguish them from gpm values.

4. The maximum probable demand in gpm is marked on the drawing for each section next to the WSFU
values. These values are obtained from Table B.5.4, using the columns for flush-tank systems.

5. Where sections of the piping serve more than one hose bibb, each additional hose bibb adds a demand
of 1 .0 WSFU to the piping. Wherever a section of piping serves a single hose bibb, it adds a demand of 2.5
WSFU.

390 2006 National Standard Plumbing Code-Illustrated

■M

e*"35

$$ s

*0)

So.W

( J !(»*> C°' 6)

wt**

idt

• C ^) 3

,-ji3

:: yjl

^*"' :

Figure B. 8.1

WATER SUPPLY FIXTURE UNITS(WSFU)

COLD WATER
HOT WATER

DESIGN BASIS

DATA for Figure B.8.1 - WATER SUPPLY FIXTURE UNITS (WSFU)

PIPING

Copper water rube, Type L
wrought fittings and lead-free solder

PUBLIC WATER SUPPLY

10 inch main, 50 psig minimum pressure

WATER CHARACTERISTICS

No significant fouling or corrosive agents

ELEVATIONS

Curb as datum
Water main
Basement floor
First floor
Second floor
Third floor

10.0 ft
6.0 ft
2.0 ft
12.0 ft
22.0 ft
32.0 ft

Highest outlet @ "K" 35.0 ft

MINIMUM OUTLET PRESSURE

15 psig required

WATER SUPPLY FIXTURE UNITS (WSFU)

Fixtures

Piping Serving

Fixtures in
1 or 2 Dwellings

Piping Serving

Fixtures in

3 or More" Dwellings

Piping Serving

Fixtures in Other

than Dwelling Units

Total

Cold

Hot

Total

Cold

Hot

Total

Cold

Hot

Bathroom Group (1 .6 GPF tank-type WC)

5.0

3.8

3.5

3.0

Half Bath (1 .6 GPF tank-type WC)

3.5

3.3

0.8

2.5

0.4

Kitchen Group (sink & dishwasher)

2.0

1.1

2.0

1.5

0.8

1.5

Clothes Washer

4.0

3.0

Service Sink

3.0

2.3

Hose Bibb

2.5

Hose Bibb, each additional

1.0

VELOCITY LIMITATIONS

8 fps

except 4 fps for branches with quick-closing valves

and 5 fps for hot water up to 140 deg F

LENGTH OF RUN TO FARTHEST OUTLET

Main - A

50 ft

A -B

12 ft

B-C

8 ft

C-D

10 ft

D-E

8 ft

E-F

8 ft

F-G

10 ft

G-H

4 ft

H-I

1 ft

1-J

10 ft

J-K

10 ft

Total = 140 ft plus fitting allowance

Hot water temperature is 140 deg F
controlled by water heater thermostat

WATER SERVICE PIPE SIZING

Fixtures

Qty

WSFU

Total

Bathroom Groups (1.6 tank-type WC) (1)

3.5

31.5

Kitchen Groups (sink + dishwasher) (1)

1.5

13.5

Clothes Washers (2)

4.0

8.0

Service Sinks (2)

3.0

6.0

Half Bath (2)

3.5

Hose Bibb (2)

2.5

Hose Bibb (each additional) (2)

1.0

TOTAL WSFU

66.0

DEMAND (GPM)

34.8

(1) Fixtures in 3 or more dwellings

(2) Fixtures in other than dwelling units.

•

Cj4

!*», s

f»f

S| Nl

S Rft ' It*'

4f i •

A *H

<&f

* 1.5

7*1

,'fO"

it ,

COLD WATER
HOT WATER

Figure B.8.2
UJ_/OlvJlN rl^WW(,OrlVlJAiNiJ rlrJ3 oIZjJc/O

Table B.8.2
PRESSURE DROPS IN THE BASIC DESIGN CIRCUIT IN FIGURE B.8.2

COLD WATER FRICTION PRESSURE DROP FROM MAIN TO "K"

SECTION

WSFU

(1)

FLOW

(gpm)

LENGTH

(feet)

PIPE
SIZE

VELOCITY

(feet/second)

(psi/lOOft)

PRESSURE
DROP (psi)

MAIN- A

66.0

34.8

1-1/2"

6.3

4.0

2.0

A -B

66.0

34.8

1-1/2"

6.3

4.0

0.5

B-C

57.6

32.0

1-1/2"

5.8

3.6

0.3

C-D

52.7

30.1

1-1/4"

7.7

8.0

0.3

D-E

44.4

26.8

1-1/4"

6.8

6.0

0.5

E-F

33.9

22.0

1-1/4"

5.6

4.0

0.3

F-G

15.4

11.4

4.4

3.2

0.3

G-H

4.9

10.0(6)

1"(4)

3.9

2.7

0.1

H- J

2.4

5.0(7)

3/4" (4)

3.3

2.7

0.3

1-J

2.2 (2)

5.0(7)

3/4" (4)

3.3

2.7

0.3

J-K

1.1(2)

2.5 (8)

1/2" (4)

3.4

4.3

0.4

Total Pipe Pressure Drop (psig)

5.3

Fitting Allowance (50% of pipe loss, psig)

2.6

Total Pressure Drop Due to Pipe Friction (psig)

7.9

HOT WATER FRICTION PRESSURE DROP FROM MAIN TO "K"

SECTION

WSFU

(1)

FLOW

(gpm)

LENGTH

(feet)

PIPE
SIZE

VELOCITY

(feet/second)

(psi/lOOft)

PRESSURE
DROP (psi)

MAIN- A

66.0

34.8

1-1/2"

6.3

4.0

2.0

A-B

66.0

34.8

1-1/2"

6.3

4.0

0.5

B- HWH

51.9

29.8

1-1/4"

7.6

7.5

0.3

HWH-C

51.9

29.8

2" (5)

3.1

0.8

0.0

C-D

47.4

28.0

1-1/2" (5)

5.0

2.7

0.3

D-E

39.1

24.6

1-1/2" (5)

4.4

2.1

0.2

E-F

30.1

20.1

1-1/2" (5)

3.6

1.6

0.1

F-G

13.5

10.3

1"(5)

4.0

3.0

0.3

G-H

4.5

4.3

3/4" (4)

2.9

2.1

0.1

H-l

4.5

4.3

3/4" (4)

2.9

2.1

0.2

J-J

4.0(2)

4.0

3/4" (4)

2.7

1.8

0.2

J-K

2.0(2)

4.0(3)

3/4" (4)

2.7

1.8

0.2

Total Pipe Pressure Drop (psig)

4.3

Fitting Allowance (50% of pipe loss, psig)

2.2

Total Pressure Drop Due to Pipe Friction (psig)

6.5

NOTES FOR PRESSURE DROP CALCULATIONS

(1) Water supply fixture units (WSFU) are for sections of piping serving 3 or more dwelling units except as noted by (2).

(2) Water supply fixture units (WSFU) are for sections of piping serving fixtures in less than 3 dwelling units.

(3) Water flow (gpm) for the dishwasher.

(4) Velocity limited to 4 fps because of dishwashers and quick -closing sink faucets.

(5) Velocity in copper tube with 140 deg F domestic hot water is limited to 5 fps using Chart B.9.8.3.

(6) Allowance of 5 gpm for the hose bibb and two sinks at 2.5 gpm each.

(7) Allowance for two sinks at 2.5 gpm each.

(8) Allowance for one sink at 2.5 gpm.

SUMMARY OF PRESSURE DROP CALCULATIONS

Minimum pressure in water main = 50.0 psig.

Water meter pressure drop = 3.0 psig

Total cold water friction pressure drop from water main to "K" = 7.9 psig

Total hot water friction pressure drop from water main to "K" = 6.5 psig

Elevation pressure drop= (35 ft - 6 ft)(0.433)= 12.6 psig

Cold water pressure available at "K" = 50-3-7.9 -12.6 = 26.5 psig

Minimum required water pressure at "K" = 15 psig

Therefore, the pipe sizing is satisfactory.

If this calculation had shown that the pressure drop was excessive at "K". it would be necessary to examine the design for sections of the Basic
Design Circuit that had the highest pressure drops and then increasse those segment pipe sizes.

394

2006 National Standard Plumbing Code-lUusmtted

•

6. All individual fixture supply pipes to water outlets are sized in Figure B.8. 1 in accordance with the
minimum sizes shown in Table B.5.2.

7. All other parts of the system are sized in accordance with the velocity or pressure limitations estab-
lished for this system as the basis of design. Piping is sized in accordance with the maximum probable
demand for each section of the system. Sizing is done using Table B.7.3A through Table B.7.3H, and
specifically the tables dealing with Copper Water Tube, Type K for sizing the water service pipe; and with
Copper Water Tube, Type L, for sizing piping inside the building since these are the materials of choice as
given in the general information on the drawing.

B.8.3 Supplementary Check of Friction Loss in Main Lines and Risers

A supplementary check of the total friction loss in the main lines and risers is made for the longest run of
piping from the public water outlet to be sure that the sizes determined were adequate. This run has been
shown in heavy lines with letters noted at various points.

The sum of all friction losses due to flow through pipe, valves, and fittings is found to be 1 7.9 psi, whereas the
amount of excess pressure available for such friction loss is 19.4 psi. Thus, the sizes determined on the basis
of velocity limitations exclusively are proven adequate. Checking of friction loss in this case is performed
following steps 8 through 1 5 of the Detailed Sizing Method for Building of Any Height presented in Section
B.10. The calculations are shown on Figure B.8.2.

B.8.4 Application to Systems in High Buildings

This method of sizing, based upon the velocity limitations that should be observed in design of building water
supply systems, has much broader application than just to systems in one-, two-, and three-story buildings
where ample excess pressure is available at the source of supply. These velocity limitations should be ob-
served in all building water supply systems. Thus, the sizes determined by this method are the minimum sizes
recommended for use in any case. Where pipe friction is an additional factor to be considered in design,
larger sizes may be required.

B.9 LIMITATION OF FRICTION

B.9.1 Basic Criterion

The design of a building water supply system must be such that the highest water outlets wilJ have available,
during periods of peak demand, at least the minimum pressure required at such outlets for satisfactory water
supply conditions at the fixture or equipment.

B.9.2 Maximum Permissible Friction Loss

The maximum allowable pressure loss due to friction in the water lines and risers to the highest water outlets
is the amount of excess static pressure available above the minimum pressure required at such outlets when
no-flow conditions exist. This may be calculated as the difference between the static pressure existing at the
highest water outlets during no- flow conditions, and the minimum pressure required at such outlets for satis-
factory supply conditions.

Where water is supplied by direct pressure from a public main, to calculate the static pressure at the highest
outlet, deduct from the certified minimum pressure available in the public main the amount of static pressure
loss corresponding to the height at which the outlet is located above the public main (i.e.. deduct 0.433 psi
pressure for each foot of rise in elevation from the public main to the highest outlet).

2006 National Standard Fltmihing Code-Illustrated 395

Where supplied under pressure from a gravity water supply tank located at an elevation above the highest
water outlet, the static pressure at that outlet is calculated as being equal to 0.433 psi pressure for each foot
of difference in elevation between the outlet and the water level in the tank. In this case, the minimum static
pressure at the outlet should be determined as that corresponding to the level of the lowest water level at
which the tank is intended to operate.

B.9.3 Basic Design Circuit

Of all the water outlets on a system, the one at which the least available pressure will prevail during periods
of peak demand is the critical outlet that controls the design. Normally, it is the highest outlet that is supplied
through the longest run of piping extending from the source of supply.

This circuit is called the Basic Design Circuit (BDC) for sizing the main water lines and risers.

In most systems, the BDC will be found to be the run of cold water supply piping extending from the source
of supply to the domestic hot water vessel plus the run of hot water supply piping extending to the highest and
most remote hot water outlet on the system. However, in systems supplied directly from the public main and
having flushometer- valve water closets at the topmost floor, the BDC may be found-to be the run of cold
water supply piping extending from the public main to the highest and most remote flushometer valve on the
system.

B.9.4 Friction Loss in Equipment

Where a water meter, water filter, water softener, fish trap or strainer, or instantaneous or tankless water
heating coil is provided in the BDC, the friction loss corresponding to the maximum probable demand through
such equipment must be determined and included in pressure loss calculations. Manufacturers ' charts and
data sheets on their products provide such information generally, and should be used as a guide in selecting
the best type and size of equipment to use with consideration for the limit to which pressure loss due to
friction may be permitted to occur in the BDC. The rated pressure loss through such equipment should be
deducted from the friction loss limit to establish the amount of pressure that is available to be dissipated by
friction in pipe, valves, and fittings of the BDC.

B.9.5 Estimating Pressure Loss in Displacement Type Cold- Water Meters

The American Water Works Association standard for cold-water meters of the displacement type is desig-
nated A WW A C 700-64. It covers displacement meters known as nutating- or oscillating-piston or disc
meters, which are practically positive in action. The standard establishes maximum capacity or delivery
classification for each meter size as follows:

5/8"

20gpm

3/4"

30 gpm

50gpm

1-1/2"

1 00 gpm

1 60 gpm

300 gpm

Also, the standard establishes the maximum pressure loss corresponding to these maximum capacities as
follows:

1 5 psi for the 5/8", 3/4" and 1 " meter sizes

20 psi for the 1 - 1/2", 2". 3". 4" and 6" sizes.

•

396 2000 National Standard Plumb tn« Cude-lllusimied

•

B.9.6 Uniform Pipe Friction Loss

To facilitate calculation of appropriate pipe sizes corresponding to the permissible friction loss in pipe, valves,
and fittings, it is recommended that the BDC be designed in accordance with the principle of uniform pipe
friction loss throughout its length. In this way, the friction limit for the piping run may be established in terms
of pounds per square inch per 100 feet of piping length. The permissible uniform pipe friction loss in psi/ 100' is
calculated by dividing the permissible friction loss in pipe, valves, and fittings by the total equivalent length of
the basic design circuit, and multiplying by 1 00.

B.9.7 Equivalent Length of Piping

The total equivalent length of piping is its developed length plus the equivalent pipe length corresponding to the
frictional resistance of all fittings and valves in the piping. When size of fittings are known, or has been
established in accordance with sizes based upon appropriate limitation of velocity, corresponding equivalent
lengths may be determined directly from available tables. Five such tables are included herein for various
piping materials. See Tables B.9.7.A through B.9.7.E.

As a general finding, it has„been shown by experience that the equivalent length to be allowed for fittings and
valves as a result of such calculations is approximately fifty percent of the developed length of the BDC in
the case of copper water tube systems, and approximately seventy-five percent for standard threaded pipe
systems.

B.9.8 Determination of Flow Rates Corresponding to Uniform Pipe Friction Loss

Flow rates corresponding to any given uniform pipe friction loss may be determined readily for each nominal
size of the kind of pipe selected for the system. Pipe friction charts 1 are presented herewith for each of the
standard piping materials used for water supply systems in buildings. The appropriate chart to apply in any
given case depends upon the kind of piping to be used and the effect the water to be conveyed will produce
within the piping after extended service.

These charts are based on piping in average service. If piping is used in adverse service or in retrofit applica-
tions, conservative practice suggests selecting lower flow rates for a given pipe, or larger pipe for a given
required flow rate.

For new work, with the range of materials now available, select a piping material that will not be affected by
the water characteristics at the site.

Table B.9.7.A
EQUIVALENT LENGTH OF PIPE FOR FRICTION LOSS IN THREADED FITTINGS & VALVES

Fitting or Valve

Equivalent Feet of Pipe for Various Pipe Sizes

1/2"

3/4"

1-1/4"

1-1/2"

2-1/2"

45 deg Elbow

0.8

1.1

1.4

1.8

2.2

2.8

3.3

4.1

5.4

6.7

8.1

90 deg Elbow, std

1.6

2.1

2.6

3.5

4.0

5.2

6.2

7.7

10.1

12.6

15.2

Tee. run

1.0

1.4

1.8

2.3

2.7

3.5

4.1

5.1

6.7

8.4

10.1

Tee. Branch

3.1

4.1

5.3

6.9

8.1

10.3

12.3

15.3

20.1

25.2

30.3

Gate Valve

0.4

0.6

0.7

0.9

1.1

1.4

1.7

2.0

2.7

3.4

4.0

Globe Valve

17.6

23.3

29.7

39.1

45.6

58.6

70.0

86.9

1 14

143

172

Angle Valve

7.8

10.3

13.1

17.3

20.1

25.8

30.9

38.4

50.3

63.1

75.8

Butterfly Valve

7.8

9.3

11.5

15.1

18.9

22.7

Swing Check Valve

5.2

6.9

8.7

11.5

13.4

17.2

20.6

25.5

33.6

42.1

50.5

NOTES FOR TABLE B.9.7.A

1 ) Equivalent lengths for valves are based on the valves being wide open.

2006 Naiionul Stundurd Plumbing Code-lllitsmned

397

Table B.9.7.B
EQUIVALENT LENGTH OF PIPE FOR FRICTION LOSS IN COPPER TUBE FITTINGS &VALVES

Fitting or Valve

Equivalent Feet of Pipe for Various Tube Sizes

1/2"

3/4"

1-1/4"

1-1/2"

2-1/2"

45 deg Elbow

0.5

1.0

1.5

2.0

2.5

3.5

5.0

6.0

7.0

90 deg Elbow, std

1.0

2.0

2.5

3.0

4.0

5.5

7.0

9.0

12.5

16.0

19.0

Tee, run

0.0

0.5

1.0

1.5

2.0

Tee, Branch

2.0

3.0

4.5

5.5

7.0

9.0

12.0

15.0

21.0

27.0

34.0

Gate Valve

0.0

0.5

1.0

1.5

2.0

3.0

3.5

Globe Valve

17.6

23.3

29.7

39.1

45.6

58.6

70.0

86.9

114.0

143.0

172.0

Angle Valve

0.0

0.5

0.0

Butterfly Valve

7.8

10.3

13.1

17.3

20.1

25.8

30.9

38.4

50.3

63.1

75.8

Swing Check Valve

7.5

10.0

15.5

16.0

11.5

13.5

Fitting or Valve

2.0

3.0

4.5

5.5

6.5

9.0

11.5

14.5

18.5

23.5

26.5

NOTES FOR TABLE B.9.7.B

1) Equivalent lengths for valves are based on the valves being wide open.

2) Data based in part on the 2004 Copper Tube Handbook by the Copper Development Association.

Table B.9.7.C
EQUIVALENT LENGTH OF PIPE FOR FRICTION LOSS IN SCHEDULE 40 CPVC FITTINGS

Fitting

Equivalent Feet of Pipe for Various Pipe Sizes

1/2"

3/4"

1-1/4"

1-1/2"

2-1/2"

45 deg Elbow

0.8

1.1

1.4

1.8

2.1

2.7

3.3

4.1

5.3

6.7

8.0

90 deg Elbow

1.5

2.0

2.6

3.4

4.0

5.1

6.1

7.6

10.0

12.5

15.1

Tee, Run

1.0

1.4

1.7

2.3

2.7

3.4

4.1

5.1

6.7

8.4

10.1

Tee, Branch

3.0

4.1

5.2

6.8

8.0

10.2

12.2

15.2

20.0

25.1

30.2

Table B.9.7.D
EQUIVALENT LENGTH OF PIPE FOR FRICTION LOSS IN SCHEDULE 80 CPVC FITTINGS

Fitting

Equivalent Feet of Pipe for Various Pi]

?e Sizes

1/2"

3/4"

1-1/4"

1-1/2"

2-1/2"

45 deg Elbow

0.7

1.0

1.2

1.7

2.0

2.6

3.1

3.8

5.0

6.4

7.6

90 deg Elbow

1.3

1.8

2.3

3.1

3.7

4.8

5.7

7.2

9.5

11.9

14.3

Tee, Run

0.9

1.2

1.6

2.1

2.5

3.2

3.8

4.8

6.3

7.9

9.5

Tee, Branch

2.6

3.6

4.7

6.3

7.4

9.6

11.5

14.3

18.9

23.8

28.5

Table B.9.7.E

EQUIVALENT LENGTH OF PIPE

FOR FRICTION LOSS IN CPVC SDR 11 CTS TUBING FITTINGS

Fitting

Equivalent Feet of Pipe for Various Pipe Sizes

1/2" CTS

3/4" CTS

1 " CTS

1-1/4" CTS

1-1/2" CTS

2" CTS

45 deg Elbow

0.8

1.1

1.4

1.8

2.2

2.8

90 dee Elbow

1.6

2.1

2.6

3.5

4.0

5.2

Tee. Run

1.0

1.4

1.8

2.3

2.7

3.5

Tee. Branch

3.1

4.1

5.3

6.9

8.1

10.3

398

2006 National Standard Plumbing Code-Illustrated

B.10 DETAILED SIZING METHOD FOR SYSTEMS IN
BUILDINGS OF ANY HEIGHT

For sizing water supply systems in buildings of any height, a detailed method may be applied in the design of
modern buildings. The procedure consists of sixteen steps, as follows:

1 . Obtain all information necessary for sizing the system. Such information shall be obtained from responsible
parties and appropriate local authorities recognized as sources of the necessary information. (See Section B.2.)

2. Provide a schematic elevation of the complete water supply system. Show all piping connections in proper
sequence and all fixture supplies. Identify all fixtures and risers by means of appropriate letters, numbers, or
combinations thereof. Identify all piping conveying water at a temperature above 1 50°F, and all branch piping to
such water outlets as solenoid valves, pneumatic valves, or quick-closing valves or faucets. Provide on the sche-
matic elevation all the general information obtained per step 1. (See Section B.2.9.)

3. Mark on the schematic elevation, for each section of the complete system, the hot and cold water loads
served in terms of water supply fixture units in accordance with Table B.5.2.

4. Mark on the schematic elevation, adjacent to all fixture unit notations, the probable maximum demand in
gallons per minute corresponding to the various fixture unit loads in accordance with Table B.5.4.

5. Mark on the schematic elevation, for appropriate sections of the system, the demand in gallons per minute
for outlets at which demand is considered continuous, such as outlets for watering gardens, irrigating lawns, air-
conditioning apparatus, refrigeration machines, and similar equipment. Add the continuous demand to the demand
for intermittently used fixtures, and show the total demand at those sections where both types of demand occur.
(See Section B.5.4.)

6. Size all individual fixture supply pipes to water outlets in accordance with the minimum sizes permitted by
regulations. Minimum fixture supply pipe sizes for typical plumbing are given in Table B.5.2.

7. Size all other pails of the water supply system in accordance with velocity limitations recognized as good
engineering practice, and with velocity limitations recommended by pipe manufacturers for avoiding accelerated
deterioration and failure of their products under various conditions of service. Sizing tables based on such velocity
limitations and showing permissible loads in terms of water supply fixture units for each size and kind of piping
material have been provided and may be applied as a convenient and simplified method of sizing in this step. (See
Section B.6)

Note: These sizes are tentative until verified in Steps 12, 13, 14, 15.

8. Assuming conditions of no-flow in the system, calculate the amount of pressure available at the topmost
fixture in excess of the minimum pressure required at such fixtures for satisfactory supply conditions. This excess
pressure is the limit for friction losses for peak demand in the system ( 1' of water column = 0.433 psi pressure).
(See Section B.9.2.)

9. Determine which piping circuit of the system is the basic one for which pipe sizes in main lines and riser
should be designed in accordance with friction loss limits. This circuit is the most extreme run of piping through
which water Hows from the public main, or other source of supply, to the highest and most distant water outlet.
This basic design circuit (BDC) should be specifically identified on the schematic elevation of the system. (See
Section B.9.3.)

10. Mark on the schematic elevation the pressure loss due to friction corresponding to the maximum probable
demand through any water meter, water softener, or instantaneous or tankless water heating coil that may be
provided in the BDC. (See Sections B.9.4 and B.9.5.)

1 1 . Calculate the amount of pressure remaining and available for dissipation as friction loss during peak demand
through pipe, valves, and fittings in the BDC. Deduct from the excess static pressure available at the topmost
fixtures (determined in step 8). the friction losses for any water meters, softeners, and water heating coils provided
in the BDC determined in step 10. (See Section B.9.4.)

12. Calculate the total equivalent length of the BDC. Pipe sizes established on the basis of velocity limitation in
step 7 for main lines and risers must be considered just tentative at this stage, but may be deemed appropriate for
determining corresponding equivalent lengths of fittings and valves in this step. (See Section B.9.7.)

2006 National Standard P/unihins Cade-IUustrand 399

GALVANIZED STEEL
ASTM A53

1000
800

1.5 T 2.5

3 4 5 6 8 10

?0 » 30 40 5060 801 00

PRESSURE DROP (psi/100')

FLOW VS. PRESSURE DROP
CHART B.9.8.1

400

2006 Ntitiuiiiil Standard Plumbing Code-Illustrated

1000
800

TYPEK
COPPER TUBE

.2 25 .3 -4 .5 .6

3 4 5 6 8 10 15 20 25 30 40 5060 80100

PRESSURE DROP (psi/100')

FLOW VS. PRESSURE DROP
CHART B.9.8.2

2006 Notional Standard Plumbing Cf>tte~-I!!it*!htrcd

401

TYPEL
COPPER TUBE

^ ^ &**

PPIZQQI ipp piPflD /nci/inn^
rKtOoUKt LJr\\Jr \pb>\f I UU )

FLOW VS. PRESSURE DROP
CHART B.9.8.3

402

2006 National Slontlurci Plwnbint> Cmle~ltluxtrsitt\l

TYPEM
COPPER TUBE

$# ^

■) JP) jg) ^ ©

.2 -"J .4 .5.6 .8 t u 2"3 4 56 8 10 ,5 20 B 30 40 5060 80100

PRESSURE DROP (psi/100')

FLOW VS. PRESSURE DROP
CHART B.9.8.4

•

2006 National Standard Pltmtlvit" Codv-llUistriiitd

403

CPVC / PVC / ABS
SCHEDULE 40 PIPE

J©

4 5 6 8 10 1S 20 ^30 40 5060 80100

PRESSURE DROP (psi/100')

FLOW VS. PRESSURE DROP
CHART B. 9.8.5

404

2000 National Standard Plumbing Cade-Illustrated

•

CPVC / PVC / ABS
SCHEDULE 80 PIPE

1000
800

.15 9 -25

2 25 .3 .4 .5 .6

1.5 n 2-5

3 4 5 6 8 10 15 20 25 30 40 5060 80100

PRESSURE DROP (psi/100')

FLOW VS. PRESSURE DROP
CHART B.9.8.6

2006 National Standard Plumbing Code-Illustrated

405

CPVC TUBING
COPPER TUBE SIZE - SDR 11)

.1 - 1S .2 -=.3 .4 .5 .6 .8 1 '•= 2 " 3 4 5 6 8 10 ' 5 20 "30 40 5060 80100

PRESSURE DROP (psi/100')

FLOW VS. PRESSURE DROP
CHART B.9.8.7

406

200b Ntttitmal St/imluril Phimbm* Cjile-lllu.wciffJ

•

13. Calculate the permissible uniform pressure loss for friction in piping of the BDC. The amount of pressure
available in the circuit for dissipation as friction loss due to pipe, fittings, and valves (determined in step 1 1 ), is
divided by the total equivalent length of the circuit (determined in step 1 2). This establishes the pipe friction limit
for the circuit in terms of pressure loss in psi per foot of total equivalent pipe length. Multiply this value by 1 00 in
order to express the pipe friction limit in terms of psi per 100 feet of length. (See Section B.9.6.)

14. Set up a sizing table showing the rates of flow for various sizes of the kind of piping to be used, correspond-
ing to the permissible uniform pressure loss for pipe friction calculated for the BDC (determined in step 1 3). Such
rates may be determined from a pipe friction chart appropriate for the piping to be used and for the effects upon
the piping of the quality of the water to be conveyed thereby for extended service. (See Sections B.9.8 and B.2.3.)

15. Check the sizes of all parts of the BDC, and all other main lines and risers which supply water upward to
the highest water outlets on the system, in accordance with the sizing table set up in step 14. Where sizes deter-
mined in this step are larger than those previously established in step 7 (based on velocity limitation), the increased
size is applicable for limitation of friction.

16. Due consideration must be given to the action of the water on the interior of the piping, and proper allow-
ance must be made where necessary as a design consideration, such as, where the kind of piping selected and the
characteristics of the water conveyed are such that an appreciable buildup of corrosion products or hard-water
scale may be anticipated to cause a significant reduction in bore of the piping system and inadequate capacity for
satisfactory supply conditions during the normal service life of the system. A reasonable allowance in such cases is
to select at least one standard pipe size larger than the sizes determined in the preceding steps. Where the water
supply is treated in such manner as to avoid buildup of corrosion products or hard-water scale, no allowance need
be made in sizing piping conveying such treated water. (See Sections B.2.3 and B.9.8.)

Bit ILLUSTRATION OF DETAILED SIZING METHOD APPLICATION

B.11.1 Example

A seven-story building is supplied by direct street pressure from a public water main in which the minimum
available pressure is 60 psi. The highest fixture supplied is 64'-8" above the public main, and requires 1 2 psi
flow pressure at the fixture for satisfactory supply conditions.

The water supply is to be metered by a meter through which tlow at the maximum probable demand rate will
produce a pressure drop of 5.6 psi. Copper tubing. Type L, is to be used for the entire system. Quality of the
water supply is known 1o be noncorrosive to copper tubing in the water district, and is recognized as being
non-scaling in characteristic.

The entire system has been initially sized in accordance with the simplified method based solely on velocity
limitations. Applying these sizes, the total equivalent length of piping from the public main to the highest and
most remote fixture outlet has been calculated to be 600'.

B.l 1.2 Solution

Steps 1-7. The first seven steps of the details sizing method have already been performed. These steps
constitute the simplified sizing method based solely on velocity limitations established as the design basis. All
that remains is to perform steps 8 through 1 5 of the detailed sizing method which relate to sizing in accor-
dance with the frictional limitation which must be observed for this particular system, and with allowances
which may be necessary in view of the water characteristics.

Step 8. Assuming conditions of no- flow in the system, the amount of excess pressure available at the
topmost fixture in excess of the minimum required at the fixture for satisfactory supply conditions is deter-
mined as follows:

•

2006 National SrunilurJ Plu»ihin» Code-lllustruied 407

Excess pressure available = 60 psi - 12 psi - (64.67 x 0.4333 psi/ft) = 20 psi

Step 9. The BDC should be specifically identified on the schematic elevation provided as per step 2.

Step 10. The pressure loss through the water meter selected for this system for flow at maximum probable
demand is given in the example as being 5.6 psi. No other items of equipment through which significant
friction losses may occur have been noted in the example.

Step 1 1 . The amount of pressure remaining for dissipation as friction loss during peak demand through
pipes, valves, and fittings in the basic design circuit is determined as follows:
Pressure available for friction in piping = 20 psi - 5.6 psi = 14.4 psi

Step 12. The total equivalent length of the basic design circuit has been given in the example as being 600
feet, based on the sizes determined in accordance with velocity limitations as per step 7.

Step 13. The permissible uniform pressure loss for friction in piping of the basic design circuit is deter-
mined as follows:

Permissible uniform pipe friction loss = 14.4 psi x (1 00 ft/600 ft)
= 2.4 psi per 100 ft pipe length

Step 14. A sizing table showing the rates of flow through various sizes of copper tubing corresponding to a
pipe friction loss rate of 2.4 psi per 100 feet of pipe length is given in Table B. 1 1.2. These flow rates were
determined from the chart applicable to such pipe with a "fairly smooth" surface condition after extended
service conveying water having the effect stated in the example.

Step 15. All parts of the BDC should be selected in accordance with the flow rates shown in the table
established in step 14. Usually, all other parts of the system are sized using the same pressure drop limitation.

TableB.11.2
TYPE L COPPER TUBING,FQR "FAIRLY SMOOTH" CONDITION

Nominal Pipe Flow Rates Corresponding to Friction
Size Loss of 2.4 psi/100'
(in) (gpm)

1/2 1.4

3/4 3.9

1 7.5
1-1/4 14.0
1-1/2 21.0

2 47.0
2-1/2 78.0

3 130.0
4 270.0

B.12 MANIFOLD TYPE PARALLEL WATER DISTRIBUTION SYSTEMS

B. 12.1 Manifolds

The total water supply demand for the dwelling shall be determined in accordance with Section 1 0.14 and
Appendix B.5. Manifolds shall be sized according to Table B.12.1 based on the total supply demand.

408 2006 Nationtil Siatuiuid Plumbing CoJe-UlusnarcJ

•

Table B.12.1
MANIFOLD SIZING 1

Nominal Size ID

Maximum GPM Available @ Velocity

Inches

@ 4 fps @8 fps

@ 10 fps

1/2 2 5 6

3/4 6 11 14

1 10 20 25

1-1/4 15 31 38

1-1/2 22 44 55

Refer to Section 10.14 for maximum velocity permitted.

B.12.2 Distribution Lines

a. The water pressure available for distribution pipe friction shall be determined from the minimum supply
pressure available at the source, the developed length and size of the water service, the pressure drop through
the water meter (if provided), the pressure drop through the manifold, the pressure drop through any other
equipment or appurtenances in the system, the elevation of each distribution line, and the minimum pressure
required at each fixture.

b. The water flow required at each fixture shall be in accordance with Section 10.14.2a for both hot and
cold water. Distribution line sizes shall be in accordance with the system manufacturer's line sizing proce-
dure.

c. The system manufacturer shall provide sizing data for the individual runs of tubing to each fixture based
on the water pressure available for pipe friction and static elevation, the GPM required at each fixture, the
tubing material, the tube size, and its maximum allowable length from the manifold to the fixture. Tube sizes
for parallel water distribution systems include 3/8" nominal, 1/2" nominal, and 3/4" nominal.

2006 National Standard Plumbing Code-Illustrated 409

Blank Page

4] 2006 Notional Standard Plumbing Code-Illustrated

x VIsJ IJv^iJI v*JI^V V-x

Customary Units to Metric

Square Measure Conversions from

Square Inches to

Approximate Square Centimeters and

Square Feet to Approximate Square Meters

Square

Inches

Centimeters

Feet

Meters

6.5

.0925

13.0

.1850

19.5

.2775

26.0

.3700

32.5

.4650

39.0

.5550

45.5

.6475

52.0

.7400

58.5

.8325

65.0

.9250

162.5

2.315

325.0

4.65

100

650.0

100

9.25

Temperature Conversions from

Degrees Fahrenheit to
Approximate Degrees Celsius

Fahrenheit <°F)

Celsius (°C)

32°

0°

40°

4°

50°

10°

60°

15°

70°

21°

80°

26°

90°

32°

100°

38°

120°

49°

140°

60°

160°

71°

180°

o^o

200°

93°

212°

100°

2006 National Standard Pfumbms Code~II fust rated

411

Liquid Volume Time Conversions
(Flow-Rate Conversions)
From Gallons Per Minute

to Approximate Litres Per Min ute

GPM

2
3
4
5
6
7
8
9
10

Litres/Minute

3.75
6.50
11.25
15.00
18.75
22.50
26.25
30.00
33.75
37.50

Liquid Volume Conversions from

Liquid Ounces and

U.S. Gallons to Litres

Ounces Litres

.0296

.0591

.0887

.1183

.1479

.1774

.2070

.2366

.2662

.2957

16(1 pt.)

.4732

.5915

.8872

32(1 qt.)

.9464

Gallons

Litres

1/4

.9464

1/2

1.893

3/4

2.839

3.785

7.571

11.36

15.14

18.93

22.71

26.50

30.28

34.07

37.85

75.71

113.6

151.4

189.3

100

378.5

Length/Time Conversions from

Feet Per Second to
Approximate Meters Per Second

Feet Per

Meters Per

Mass Conversions from

Second

Ounces and Pounds to Kilogr:

ams

.3050

.610

.915

1
2

Ounces

Kilograms

Pounds

Kilograms

1.220

.028

.454

1.525

.057

.907

1.830

.085

1.361

2.135

.113

1.814

2.440

.142

2.268

2.754

.170

2.722

3.05

.198

3.175

.227

3.629

.255

4.082

10
11

.283
.312

4.536
11.34

.340

22.68

.369

34.02

.397

100

45.36

.425

16(1 lb.)

.454

412

2006 NoiitJin

ill Sla

nclarc! Pliimbinii Coile-Illustraicd

Appendix D

Determining the Minimum Number of
Required Plumbing Fixtures

The determination of the minimum number of required plumbing fixtures is a complex issue as many buildings are
unique as such the Authority Having Jurisdiction is called upon to use good judgement in applying this procedure.

1. DETERMINE THE SERVICE POPULATION

The population for the building or facility should be given on the plans. In the event the population of the building
or service area is not given on the plans, three approaches may be utilized in determining the population to be
served by the restroom facility.

( a.) Actual: In some instances the actual population, male and female, of the building service area may be
known and this value may be used in the calculations.

(b) Engineering Estimate: The population of many buildings, especially those owner-occupied, may be
determined on the basis of population densities. Typically, office building floor areas range from 200 to 400 square
feet per person. In the absence of other data, the gender ratio should be 60/60 which allows for a variance.

(c) Legal Limit: Many building codes establish a legal occupancy limit based on the means of egress. Where
the occupant load is based on the egress requirements of a building, the number of occupants for plumbing pur-
poses shall be permitted to be reduced to two-thirds of that required for fire or life safety purposes.

2. MINIMUM NUMBER OF REQUIRED PLUMBING FIXTURES

The minimum number of required plumbing fixtures shall be determined based on building classification, user group
and population as given in Table 7.2 1 . 1 . The building classifications and user groups are consistent with nationally
recognized building codes.

EXAMPLE A

Building classification, use group, total population must be known.

Building classification:
Use Group:
Floor area:
Population

Assembly

A-3, auditorium without permanent seating

20,000 net square feet, 1 story

2,857 based on egress per the Building Code at 7 sq ft per person

2006 Natumal Standard Pfttmhirtg Codi'-ltlustrati-d

413

1. Determine the Plumbing Population

Since the given population is based on egress requirements, the population for plumbing purposes can be 2/3 of
that value (Section 7.21.2.b). The ratio of male and female occupants can be assumed to be 50% each (Section
7.21.2.c).

Population for plumbing purposes = 2857 x 2/3 = 1 905
Male population = 1905 x 50% = 953
Female population = 1 905 x 50% = 953

2. Determine the Minimum Required Number of Plumbing Fixtures

The minimum required number of plumbing fixtures is determined from Table 7.2 1 . 1 under

No. 1 Assembly, Use Group A-3

The number of males and females are greater than the numerical groups listed in Table 7.21.1 . To determine the
totaLnumber of fixtures required, calculate the number of fixtures required by the listed numerical groups and then
determine how many additional groups of 300 there are over the first 300.

Male Water Closets

first 50 men ( 1 -50) = 1 water closet

next 100 men (51-150) = add 1 water closet

next 1 50 men (151 -300) = add water closet

add 1 for each additional group of 300 over 300 (or parts thereof)

The listed numerical groups account for the first 300 males

The number of additional groups of 300 = (953 - 300) divided by 300 per group = 2.18 = 3 groups

The total number of male water closets = 1 (first 50)

= 1 (next 100)
= 0(next 150)
= 3 (3 additional groups of 300 @ 1 each)

Minimum number of water closets for males = 5

Section 7.21 .5. a permits urinals to be substituted for up to 50% of the required water closets.

The male toilet room could contain 3 water closets and 2 urinals.

Female Water Closets

first 50 females (1-50) = 1 water closet

next 100 females (51-150) = add 1 water closet

next 1 50 females ( 1 5 1 -300) = add water closet

add 2 for each additional group of 300 over 300 (or parts thereof)

The listed numerical groups account for the first 300 females.

The number of additional groups of 300 = (953 - 300) divided by 300 per group = 2.18 = 3 groups

The total number of female water closets = 1 (first 50)

= 1 (next 100)
= 0(next 150)
= 6 (3 additional groups of 300 @ 2 each)

414 2006 National Standard Plumbing Code-Illustrated

Minimum number of water closets for females = 8

Male Lavatories

first 50 males (1-50) = 1 lavatory

next 1 00 males (51-1 50) = add lavatories

next 150 males (151-300) = add lavatories

add 1 for each additional group of 300 over 300 (or parts thereof)

The total number of male lavatories

1 (first 50

(next 100)

next 150)

3 (3 additional groups of 300 @ 1 each)

Minimum number of lavatories for males = 4

Female Lavatories

first 50 females (1-50) = 1 lavatory

next 100 females (51-150) = add 1 lavatory

next 150 females (151-300) = add lavatories

add 2 for each additional group of 300 over 300 (or parts thereof)

The total number of female lavatories

= 1 (first 50

= 1 (next 100)

= next 1 50)

= 6 (3 additional groups of 300

2 each)

Minimum number of lavatories for females = 8

Drinking Water Facilities

Table 7.21.1 requires 1 per 1000 people (or parts thereof)

Number of drinking water facilities = 1 905 divided by 1000 per group

Service Sinks

Table 7.21 .1 requires a minimum of 1 per floor.

1 .905 = 2 groups

2006 National Standard Plumbine Coih'-Itlusirated

415

EXAMPLE B ^^

Building classification, use group, total population must be known.

Building classification: Business

Use Group: B, office building

Floor area: 48,300 net square feet, 1 story

Population 386 based on expected occupancy

1. Determine the Plumbing Population

Population for plumbing purposes = 386
Male population = 386 x 50% = 1 93
Female population = 386 x 50% = 1 93

2. Determine the Minimum Required Number of Plumbing Fixtures

The minimum required number of plumbing fixtures is determined from Table 7.21.1 under
No. 2 Business, Use Group B

The number of males and females are greater than the numerical groups listed in Table 7.2 1 .1 . To determine the
total number of fixtures required, calculate the number of fixtures required by the listed numerical groups and then
determine how many additional groups of 60 there are over the first 75.

Male Water Closets

first 1 5 men (1-15)= 1 water closet

next 25 men ( 1 6-40) = add 1 water closet

next 35 men (40-75) = add 1 water closet

add 1 for each additional group of 60 over 75 (or parts thereof)

The listed numerical groups account for the first 75 males

The number of additional groups of 60 = ( 193 - 75) divided by 60 per group - 1 .97 = 2 groups

The total number of male water closets = 1 (first 15)

= 1 (next 25)
= 1 (next 35)
= 2(2 additional groups of 60 @ 1 each)

Minimum number of water closets for males = 5

Section 7.21 .5a permits urinals to be substituted for up to 50% of the required water closets.

The male toilet room could contain 3 water closets and 2 urinals.

Female Water Closets

first 15 females (1-15)= 1 water closet

next 25 females (16-40) = add 1 water closet

next 35 females (40-75) = add 1 water closet

add 2 for each additional group of 60 over 75 (or parts thereof)

The listed numerical groups account for the first 75 females.

416 2006 National Stundard Plumbing Code-lilustraii-d

•

The number of additional groups of 60 = (193 - 75) divided by 60 per group = 1 .97 = 2 groups

The total number of female water closets = 1 (first 15)

= 1 (next 25)
= 1 (next 35)
= 4 (2 additional groups of 60 @ 2 each)

Minimum number of water closets for females = 7

Male Lavatories

first 15 males (1-15)= 1 lavatory

next 25 males ( 1 6-40) = add lavatories

next 35 males (40-75) = add 1 lavatory

add 1 for each additional group of 60 over 75 (or parts thereof)

The total number of male lavatories

= 1 (first 15

= (next 25)

- 1 (next 35)

= 2 (2 additional groups of 60 @ 1 each)

Minimum number of lavatories for males = 4

Female Lavatories

first 15 females (1-15) = 1 lavatory

next 25 females (16-40) = add 2 lavatories

next 35 females (41-75) = add 1 lavatories

add 2 for each additional group of 60 over 75 (or parts thereof)

The total number of female lavatories

= 1 (first 1 5)
= 2 (next 25)
= 1 (next 35)
= 4 (2 additional groups of 60 @ 2 each)

Minimum number of lavatories for females = 8

Drinking Water Facilities

Table 7.21.1 requires 1 per 1000 people (or parts thereof)

Number of drinking water facilities = 386 divided by 1000 per group = 0.39

Service Sinks

Table 7.21.1 requires a minimum of I per floor.

1 group

•

2006 National Standard Plumbing Code— Illustrated

417

Blank Page

418 20U6 Nationnl Standard Plumbing Code-Illustrated

•

Appendix E

Special Design
Plumbing Systems

E.l GENERALrREQUIREMENTS

E.1.1 Special design plumbing systems shall include all systems that vary in detail from the requirements of
this Code.

E.l .2 The provisions of this Appendix shall control the design, installation, and inspection of special design
plumbing systems.

E.l. 3 Special design plumbing systems shall conform to the Basic Principles of this Code.

E.l .4 Special design plumbing systems shall be designed by a registered design professional who is licensed to
practice in the particular jurisdiction.

E.2 PLANS,SPECIFlCATIONS,ANDCOMPTJTATIONS

E.2.J Plans, specifications, computations, and other related data for special design plumbing systems,
prepared by the registered design professional, shall be submitted to the Authority Having Jurisdiction for
review and approval prior to installation.

E.2.2 The design plans shall indicate that the plumbing system (or portions thereof) is a special design
system.

E.3 INSTALLATION OF SPECIAL DESIGN PLUMBING SYSTEMS

E.3.1 Special design plumbing systems shall be installed according to established, tested and approved criteria,
including manufacturer's instructions.

E.3.2 The installation shall comply with Chapter 2 - General Regulations and other applicable requirements
of this Code.

•

2006 National Snmclanf Plumliina Code-lllustiatcd

419

E.4 CERTIFICATION OF COMPLIANCE

E.4.1 Inspections shall be made by the Authority Having Jurisdiction to ensure conformance with data
submitted for approval and the applicable requirements of this Code.

E.4.2 The complete installation and performance of the special design plumbing system shall be certified
by the registered design professional as complying with the requirements of the special design.

E.5 VACUUM DRAINAGE SYSTEMS
E.5.1 General Requirement

E.5.1.1 System Design

Vacuum drainage systems shall be designed in accordance with manufacturer's recommendations. The
system layout, including piping layout, tank assemblies, vacuum pump assembly and other components/
designs necessary for proper function of the system shall be per manufacturer's recommendations. Plans,
specifications and other data for such systems shall be submitted to the Authority Having Jurisdiction for
review and approval prior to installation.

E.5.1 .2 Fixtures

Gravity type fixtures used in vacuum drainage systems shall comply with Chapter 7 of this Code.

E.5.1.3 Drainage Fixture Units

Fixture units for gravity drainage systems that discharge into or receive discharge from vacuum drainage
systems shall be based upon values in Chapter 1 1 of this Code.

E.5.1. 4 Water Supply Fixture Units

Water supply fixture units shall be based upon values in Chapter 10 of this Code with the addition that the
fixture unit of a vacuum type water closet shall be one inch.

E.5. 1.5 Traps and Cleanouts

Gravity type fixtures shall be provided with traps and cleanouts per Chapter 5 of this Code.

E.5.1. 6 Materials

Vacuum drainage pipe, fittings and valve materials shall be as recommended by the vacuum drainage
system manufacturer and as permitted by this Code.

E.5.2 Tests and Demonstrations

After completion of the entire system installation, the system shall be subjected to a vacuum test of 19 inches
of mercury and shall be operated to function as required by the Authority Having Jurisdiction and the manu-
facturer. Recorded proof of all tests shall be submitted to the Authority Having Jurisdiction.

420 2006 Nationol Standard Plumbing Code-lllustrared

E.5.3 Written Instructions

Written instructions for the operation, maintenance, safety and emergency procedures shall be provided to the
Building Owner as verified by the Authority Having Jurisdiction.

E.6 ONE-PIPE SANITARY DRAINAGE SYSTEMS EMPLOYING AERATOR AND
DEAERATOR STACK FITTINGS

E.6.1 Compliance

a. One-pipe sanitary drainage systems employing aerator and deaerator stack fittings shall be permitted to be
installed in accordance with ( 1 ) the fitting manufacturer's current piping design manual and technical bulletins,
and (2) the applicable requirements of this Code.

b. The requirements of this Code shall supercede the fitting manufacturer's piping design manual with regard
to acceptable piping materials, drainage fixture unit (DFU) values, and minimum drainage pipe sizes.

c. Complete detailed layout drawings shall be prepared prior to the installation of such a sanitary drainage
system.

E.6.2 Piping Materials

Piping materials for drainage stacks and branches shall be in accordance with Section 3.5 of this Code. Piping
materials for vents shall be in accordance with Section 3.6 of this Code.

E.6.3 Drainage Fixture Unit (DFU) Values

Drainage fixture unit values for bathroom groups and individual fixtures shall be in accordance with Table 1 1.4.1
of this Code.

E.6.4 Drainage Pipe Sizing

Piping in such a sanitary drainage system shall be sized according to the fitting manufacturer's current piping

design manual.

EXCEPTION: Drainage pipe sizes shall not be less than those required by Section 1 1.5 of this Code.

E.6.5 Arrangement of Piping

Piping shall be arranged as illustrated in the fitting manufacturer's current design manual.

E.7 SINGLE STACK VENT SYSTEMS

E.7.1 Where permitted.

A drainage stack shall be permitted to serve as a single stack vent system when sized and installed in accordance
with Sections E. 7.2 through E.7. 9. The drainage stack and branch piping in a single stack vent system shall provide
for the flow of liquids, solids, and air without the loss of fixture trap seals.

E.7.2 Stack Size

Drainage stacks shall be sized according to Table E.7.2. A maximum of two water closets shall be permitted to
discharge to a 3 inch stack. Stacks shall be uniformly sized based on the total connected drainage fixture unit load
with no reductions in size.

2006 National Standard Pfmiibinu Code-lfliistratcJ

421

Table E.7.2
SINGLE STACK SIZE

Stack Size
(inches)

Maximum Connected Drainage Fixture Units

Stacks Less than 75
Feet in Height

Stacks 75 Feet to Less than 160
Feet in Height

Stacks 160 Feet or
Greater in Height

24 (2)

225

480

225

1015

480

225

2320

1015

480

4500

2320

1015

8100

4500

2320

13,600

8100

4500

1 . NP = not permitted

2. Not more than two (2) water closets are permitted on a 3" stack.

E.7.3 Branch Size

Horizontal branches connecting to a single stack vent system shall be sized according to Table 1 1 .5.1 B.

EXCEPTIONS:

(1) No more than one water closet within 1 8" of the stack horizontally shall be permitted on a 3" horizontal
branch.

(2) A water closet within 1 8" of a stack horizontally and one other fixture with up to 1-1/2 inch fixture drain
size shall be permitted on a 3" horizontal branch when connected to the stack through a sanitary tee.

E.7.4 Length of Horizontal Branches

a. Water closets shall be no more than four (4) feet horizontally from the stack.

EXCEPTION: Water closets shall be permitted to be up to eight (8) feet horizontally from the stack when
connected to the stack through a sanitary tee.

b. Fixtures other than water closets shall be no more than twelve (12) feet horizontally from the stack.

c. The length of any vertical piping from a fixture trap to a horizontal branch shall not be considered it computing
the fixture's horizontal distance from the stack.

E.7.5 Maximum Vertical Drops From Fixtures

Vertical drops from fixture traps to horizontal branch piping shall be one pipe size larger than the trap but not less
than two (2) inch pipe size. Vertical drops shall be four (4) feet maximum length. Fixture drains that are not
increased in size, or have a vertical drop exceeding 4 feet shall be individually vented.

E.7.6 Additional Venting Required

Additional venting shall be provided when more than one water closet is on a horizontal branch and where the
distance from a fixture trap to the stack exceeds the limits in Section 1 2. 1 8.4. Where additional venting is required,
the fixture(s) shall be vented by an individual vent, common vent, wet vent, circuit vent, or a combination waste
and vent pipe. The dry vent extensions for the additional venting shall connect to a branch vent, vent stack, stack
vent, air admittance valve, or be extended outdoors and terminate to the open air.

422

2006 Ntuioinil Sltnulurd Plumbing Cutle-I/lusirau-J

E.7.7 Stack Offsets

Where there are no fixture drain connections below a horizontal offset in a stack, the offset does not need to be
vented. When there are fixture drain connections below a horizontal offset in a stack, the offset shall be vented
in accordance with Section 1 2.3.3. There shall be no fixture connections to a stack within 2 feet above and below
a horizontal offset.

E.7.8 Separate Stacks Required

Where stacks are more than two stories high, a separate stack shall be provided for the fixtures on the lower two
stories. The stack for the lower two stories may be connected to the branch of the building drain that serves the
stack for the upper stories at a point that is at least 10 pipe diameters downstream from the base of the upper
stack.

E.7.9 Sizing Building Drains and Sewers

The building drain and branches thereof, and the building sewer in a single stack vent system shall be sized in
accordance with Table 1 1.5.1 A.

JE.8 AIR ADMITTANCE VALVES

E.8.1 Definition

Air admittance valve: A one-way valve designed to allow air to enter the plumbing drainage system when negative
pressures develop in the system. The device closes by gravity, without springs or other mechanical means, and
seals the vent terminal at zero differential pressure (no flow conditions) and also under positive internal pressure.
The purposes of an air admittance valve are ( 1 ) to provide a method of allowing air to enter the plumbing drainage
system without the need for a vent extended outdoors to open air, and (2) to prevent sewer gases from escaping
into the building.

E.8.2 Where Permitted

E.8.2.1 Branch, circuit, common, continuous, and individual vents shall be permitted to terminate with a
connection to an individual or branch type air admittance valve complying with ASSE 1 05 1 . Individual and branch
type air admittance valves shall only vent fixtures that are on the same floor level and connect to a horizontal
branch drain.

E.8.2.2 Vent stacks and stack vents shall be permitted to terminate at a stack type air admittance valve

complying with ASSE 1050.

EXCEPTIONS

(1) Vent stacks and stack vents serving drainage stacks that exceed six (6) branch intervals in height.

(2) Vent stacks and stack vents that serve relief vents in Section E.8.3.

E.8.2.3 Air admittance valves shall not be permitted in the following applications:

a. vents for special waste drainage systems (Sections 9.4.1 and 9.4.2).

b. vents for sewage pump or ejector sump pits.

c. vents for pneumatic sewage ejectors.

d. suds pressure zone venting.

e. relief vents required by Section E.8.3. 1.

2(M)6 National Standard Plumbing Cutle—lllusmitcd

423

E.8.3 Relief Vents

E.8.3.1 A relief vent shall be provided where a horizontal branch drain that is vented by one or more air
admittance valves connects to a drainage stack more than four (4) branch intervals from the top of the stack. The
relief vent shall connect vertically to the horizontal branch drain between the drainage stack and the most
downstream fixture drain connection on the horizontal branch drain. Relief vents shall extend from the horizontal
branch drain to a vent stack, stack vent, or other vent that terminates outdoors in open air.

E.8.3.2 Relief vents shall be the full size of the horizontal branch drain that they serve, up to 3" maximum required
size.

E.8.3.3 Relief vents shall be permitted to vent fixtures other than those on the horizontal branch chain being
relieved.

E.8.4 Installation

E.8.4.1 Air admittance valves shall be installed in accordance with the manufacturer's instructions and Section
E.8.

E.8.4.2 Air admittance valves shall connect to fixture trap arms within the maximum allowable trap arm lengths
in Table 12.8.1.

E.8.4.3 Individual and branch type air admittance valves shall be installed at least 4 inches above the top of the
trap arm or horizontal branch drain that they serve.

E.8.4.4 Stack type air admittance valves shall be installed at least 6 inches above the flood level rim of the highest
fixture served by the valve.

E.8.4. 5 Air admittance valves shall be installed in accessible locations having free movement of air to enter the
valve.

E.8.4.6 Air admittance valves shall not be installed in H VAC supply or return air plenums or other areas subject
to other than atmospheric pressure.

E.8.4.7 Air admittance valves installed in insulated attic or ceiling spaces shall be installed in free air at least six
inches above the insulation.

E.8.4.8 Air admittance valves shall be the same size as the vent pipe to which they are connected.

E.8.4.9 Air admittance valves shall not be installed until all required leak tests of the drainage and vent piping
are successfully completed.

E.8.5 Vent to Outdoors Required

In each plumbing drainage system vented by one or more air admittance valves, at least one vent shall extend
outdoors to open air.

424 2006 National Standard Plumbing Cudc-HlusrraicJ

E.8.6 Referenced Standards

E.8.6.1 ASSE 1050-2002 Stack Air Admittance Valves for Sanitary Drainage Systems.

E.8.6.2 ASSE 1 05 1 -2002 Individual and Branch Type Air Admittance Valves for Plumbing Drainage Systems.

2006 National Standard Plumbing Coda— Illustrated

425

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426 . 2006 Natrona! Standard Plumbing Code— Illustrated

•

Appendix F

Requirements of the
Authority Having Jurisdiction

F.1 CjJlyjVlLivALi

This Code does not include specific requirements in certain cases where local practices may vary from one
jurisdiction to another. This appendix lists those sections of this Code where the Authority Having Jurisdiction must
establish requirements. Adopting agencies should review the sections listed under Appendix F.2 and establish
appropriate regulations or policies.

F.2 REFERENCES

1.7.2 Penalties

1.9.8 Permit Expiration

1.10.2 Plan Review Fees

1 . 1 0.3 Plan Review Expiration
j.10.5 Refunding of Fees
1.11.5 Requests for Inspection

2.1 6.1 : Minimum earth cover for water service pipe.

2. 1 6.2: Minimum earth cover for building sewers.

2.19.1: Distance for required connections to public water supplies and sewers.

2.19.2: Standards and requirements for private water and sewage disposal systems.

5.3.4: Need for building traps.

5.4.10.c: Manhole construction standards,

6.1 .7: Point of discharge for effluent from liquid waste treatment equipment.

7.1 6.6: Sloping floors to floor drains.

9.4.3.C Points of discharge for air conditioning condensate.

10.9.2: Disinfecting water piping.

1 1 .7.6: Use of grinder pumps.

1 1 .7.1 0: Use of macerating toilet systems.

1 5.3.1 : Testing new plumbing work.

1 5.3.2: Testing existing sewers and drains.

16. 1: State or local requirements for private sewage disposal systems.

Chapter 18: Regulations of the AH J for mobile home and travel trailer parks.

2006 NuuoMtt Standard Plumbum Cttde-iliitM fitted

427

F.3 EXCEPTIONS, WAIVERS, APPROVALS

There are instances where this Code specifically permits exceptions or waivers of its requirements and the
approval of alternative materials and methods by the Authority Having Jurisdiction. These occur throughout this
Code.

•

428 2UU6 Nativtwl Standard Plumbing Code-Illustrated

Appendix G

Graywater Recycling

ystems

•

2006 National Standard Plumhinn Code-llluxtriiicd

429

G.1 FOREWORD

In the United States today, regulations concerning water conservation, moratoriums on sewer connections, and
restrictions on sewer permits are a clear indication of a growing economy restrained by a lack of available water.
Water being a finite resource, these actions serve as a warning that without adequate planning for our future water
needs, America is facing a critical water supply shortage.

In virtually all major metropolitan and many suburban areas in the country, water treatment plants are over-
loaded and many, due to neglect and deferred maintenance, are beginning to fail. Finding additional water sources
and supplies and expanding existing water treatment plant capacity is expensive, sometimes impractical, and at
best, involves long range planning.

Traditionally, the municipal treatment facility has been the primary source of water disposal for single and multi-
family residential buildings and complexes. As long term water shortages increasingly are predicted in several
areas across the nation, water conservation becomes more of a national issue. Fortunately, alternative technical
solutions are currently available.

Various potentially useful and dependable water treatment and recycling technologies are being explored. One
possible source is graywater recycling, an on-site wastewater treatment and recycling system, also known as
"Graywater Systems". This promising technology offers a practical solution to the water shortage problem as it
applies to plumbing installations. Graywater systems are designed to safely manage wastewater and reduce water
consumption. Graywater systems can be used in all types of residential, commercial, institutional, and industrial
buildings. Some graywater applications include toilet and urinal flushing, landscape irrigation, supply water for
ornamental ponds and make-up water for cooling towers.

G.2 DEFINITIONS

Biological Treatment: A method of wastewater treatment in which bacterial or biochemical action is
intensified as a means of producing an oxidized wastewater.

Black Water: Used untreated water that is flushed down toilets and urinals. This water cannot be directly
reused.

Effluent: Partially or completely treated liquid waste discharge from a wastewater treatment system.

Graywater: Used untreated water generated by clothes washing machines, showers, bathtubs and lavatories.
It shall not include water from kitchen sinks or dishwashers.

Reclaimed Water: Effluent from a wastewater treatment facility that has been subjected to extensive
treatment in order to remove organic material, heavy metals, and harmful pathogens (such as bacteria,
viruses, and protozoa). Reclaimed water is non-potable.

Septic Tank: A water-tight receptacle that receives the discharge of a building sanitary drainage system or
part thereof, and is designed and constructed so as to separate solids from the liquid, digest organic matter
through a period of detention, and allow the liquids to discharge into the soil outside of the tank through a
system of open joint or perforated piping, or a seepage pit.

Wastewater: The combination of liquid and water-earned pollutants from residences, commercial buildings,
industrial plants, and institutions.

430 2006 National Standard Plumhin.ii Coile-lllustratcd

G3 APPROVED MATERIALS

All materials, fixtures or equipment used in the installation, repair or alteration of graywater systems, shall conform
to the standards set forth in Chapter 3 of this Code. Nothing contained herein shall prohibit the Authority Having
Jurisdiction from imposing more stringent requirements.

Materials not listed in Chapter 3 of this Code may be used with the approval of the Authority Having Jurisdiction
as permitted in Section 3.12.2.

G.4 APPROVED INSTALLATIONS

Prior to construction of a graywater system, the appropriate permits shall be obtained from the Authority Having
Jurisdiction having jurisdiction. The applicant shall provide the Authority Having Jurisdiction with complete plans
and manufacturers' recommendations of the proposed installation.

AH pipe sizing and installation procedures shall conform to the applicable sections of this Code. Nothing shall
preclude the Authority Having Jurisdiction from requiring more stringent compliance procedures.

G.5 PROHIBITED INSTALLATIONS

Surface draining graywater shall not be permitted to collect on the surface of the ground or to run off the property.
Graywater shall not be permitted to come in direct contact with edible food sources.

G.6 ACCEPTABLE TREATMENT METHODS

G.6.1 Nylon or Cloth Filter

The nylon or cloth filter system typically consists of a filter bag connected to the graywater inlet pipe in a
tank. The graywater is passed through the filter media (that collects hair and lint) and proceeds on for further
treatment.

G.6.2 Sand Filter

The sand filter system consists of a sand and rock filled tank with an underdrain system. The graywater is
poured onto splash plates and then filtered through filter media, while receiving physical and biological treat-
ment. The filtered graywater then is collected and transported via an underdrain system for reuse.

G.6.3 Diatoinaceous Earth Filter

Diatomaceous filters are commonly used for filtering water for swimming pools and spas. The use of this
type of filter is primarily limited to separating solids in suspension with the use of a recirculating line.

G.6.4 Rack or Grate Filters

The primary function of the rack or grate filter is to remove particle matter from the graywater.

G.6.5 Collection and Settling

Commonly found in septic systems, whereby solids flow into the tank and are permitted to settle to the bottom
forming a sludge layer.

G.6.6 Biological Treatment Units

Typically a process in which solids are separated through the use of three chambers. Pre-settling, aeration,
and final settling separate the solids while allowing biological treatment prior to reuse. This type of treatment
is usually found in large commercial applications.

2006 National Standard Plumbing Cude-lllitstnttcd 431

G.6.7 Reverse Osmosis 4j^

A process involving treatment of the gray water by a reverse osmosis unit. ^JP

G.6.8 Physical/Chemical Treatment

Graywater is processed through a rapid mix tank in which polymer and activated carbon are added. The
treated graywater is then passed through a settling tank in which sludge is removed. The graywater then
goes on to numerous filters for further treatment.

G.7 DISINFECTION TECHNIQUES

Ultraviolet Irradiation

Ozone

Chlorine

Iodine

G.8 IRRIGATION METHODS

Mini-Leachfield
Drip Irrigation

G9 PROTECTION OF THE POTABLE WATER SUPPLY

A graywater system shall be designed, installed and maintained to prevent contamination from non-potable liquids,
solids or gases into the potable water supply through cross-connections.

In all buildings w r here dual water systems are installed, one potable water and one non-potable water, each
system shall be identified either by color marking or metal tags, or other appropriate method as approved by the
Authority Having Jurisdiction having jurisdiction. Each outlet on the non-potable water line that may be used for
drinking or domestic purposes shall be posted: DANGER — UNSAFE WATER.

The potable water supply shall be protected from backflow and back-siphonage by an approved method of
cross-connection control required by Sections 10.4 and 10.5 of this Code. Nothing contained herein shall prohibit
the Authority Having Jurisdiction from requiring more stringent requirements.

G.10 TESTING

All applicable sections of this appendix shall conform to the body of this Code. Installation of the graywater
system shall conform in all aspects to the manufacturers recommended installation procedures.

Systems shall be tested and comply with the Authority Having Jurisdiction. Pipmg, valves, and fittings shall be
tested in compliance with Chapter 15 of this Code.

G.11 MAINTENANCE

The graywater system shall be maintained in accordance with the manufacturers recommended maintenance
instructions.

Nothing in this Appendix shall preclude the Authority Having Jurisdiction from requiring additional maintenance
procedures.

•

432 2006 National Standard Plumbini; Cutle-lllusiralid

Appendix H

INSTALLATION OF

MEDICAL GAS

AND VACUUM PIPING

SYSTEMS

(Refer to NFPA 99-2005 or NFPA 99C-2005)

2006 National StunJunf Plumbing CuJe-llluxirtHcd

433

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434 2006 Nutionul Standard Plumbing Coite-UlustrateJ

Appendix I

Fixture Unit Value
Curves for Water Closets

•

2006 National Swndard Plumbing Code-lllusimied

435

1.1 DRAINAGE FIXTURE UNITS — WATER CLOSETS

lo
*

Chart 1.1(a)

Drainage Fixture Units - Water Closets
Heavy Use Assembly

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

Flush Volume (Gallons)

Gravity q=1 6

Valve q=192

Press Tank q=32

■E

10
8
6
4

Chart 1.1(b)

Drainage Fixture Units - Water Closets
Other than Dwellings

0.2 0.4 0.6 0.8 1 1.2

Flush Volume (Gallons)

1.4

1.6

1.8

-*— Gravity q=16

Valve q=1 92 — •— Press Tank q=32

c
u

8
6
4
2

Chart 1.1(c)

Drainage Fixture Units - Water Closets
Dwellings

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Flush Volume (Gallons)

— a— Gravity q=16 —a— Valve q=1 92 — «— Press Tank q=32

436

2006 National Standard Plumbing Code-Hhisiraivd

1.2 WATER SUPPLY FIXTURE UNITS — WATER CLOSETS

Chart 1.2(a)

Water Supply Fixture Units - Water Closets
Heavy Use Assembly

3 6

3 4

■y^z- 55 -"

-4~

0.2 0.4 0.6 0.8 1 1.2

Flush Volume (Gallons)

1.4

1.6

1.8

Press Tank
q=1.5

Gravity q=2.4

Valve q=20

Valve q=24

Chart 1.2(b)

Water Supply Fixture Units - Water Closets
Dwellings and other Services

~ 6

a 4

2
1

-+-

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

Flush Volume (Gallons)

Press Tank
q=1.5

Gravity q=2.4 — ♦-- Valve q=20

Valve q=24

2006 National Standard Plumbing CoJe-lllifstriitcd

437

Blank Page

438 2006 National Standard Plumbing Code-Must) cited

Appendix J

Sizing Grease
InterceDtors

•

2006 Natiomil Standard Plumhin" Code-IIlustnitcrf

439

One Acceptable Method of Sizing Grease Interceptors

Waste waters that are not grease laden and do not require separation shall not be discharged into any grease
interceptor.

1 . Determine the cubic content of the fixture, equipment or sink compartment that will produce the grease
laden waste water that wil 1 require separati on . Length x Wi dth x Depth

2. Determine the capacity in gallons. 1 gallon = 231 cubic inches.

3 . Determine the actual drainage load.

a. The fixture is usually filled to about 75% of capacity with water.

b. The items being washed displace about 25% of the fixture content.

c. Actual drainage load = 75% of the fixture, equipment or sink compartment.

4. Determine the drainage rate.

a. In general, good practices dictate a one minute drainage period.

b. However where conditions permit, a 2-minute drainage period is acceptable.

c. Drainage rate = Drainage period is the actual time required to completely drain the unit.

5. Determine the flow rate.

Flow rate = Actual drainage load (divided by) Drainage rate.

6. Select trap size based on calculated drainage rate and flow rate.

•

440 200b National Slciiulurd Plumbing CuJe-Ulusmitcd

Appendix K

ow In

SloBins Drains

•

2006 National Standard Plumbing Code-Illustrated

441

Flow in Sloping Drains

Tables K-l and K-2 list flow rates in gallons per minute and velocities in feet per second for various
size drains at various slopes. Table K-l is based on fairly rough pipe. Table K-2 is based on smooth
pipe.

The minimum flow velocity to achieve scouring in horizontal sanitary drain lines is two (2) feet per
second. For this reason, based on Table K-2 for smooth pipe, drains that are 2 inches and smaller
must be sloped at not Jess than 1/4 inch per foot. Drains that are 3" size and larger can be sloped at 1/
8 inch per foot.

Even at 1/4" per foot slope, the uniform velocity in drains that are 1-1/4", 1-1/2", and 2" size is less
than 2 feet per second. Either the slope should be increased or the length of such drains should be
kept to a minimum so that the entrance velocity will provide scouring for the short distance involved.

Tables K-l and K-2 are based on the Manning Formula for 1/2 full pipe. For full flow, multiply the
flow by 2.00 and the velocity by 1.00. For 1/4 full flow, multiply the flow by 0.274 and the velocity
by 0.701. For 3/4 full flow, multiply the flow by 1.82 and the velocity by 1.13.

In Table K-L which is based on fairly rough pipe with "n" = 0.015. for smoother pipe, multiply the flow
and velocity by 0.015 and divide by the "n" value of the smoother pipe.

Horizontal sanitary drain and waste pipes are sized to be one-half (1/2) full under design loads.
Horizontal storm drains are sized to run full under design loads.

Table 11. 5.1 A "Building Drains and Sewers'' and the horizontal piping in Table 11. 5. IB "Horizontal
Fixture Branches and Stacks" is based on Table K-2 for smooth pipe.

Table 13.6.2 "Size of Horizontal Storm Drains" is based on Table K-l for fairly rough pipe, adjusted for
full How.

•

442 2006 Natiuiuil Smntfard Plumbing CoJe-Illii.waici/

•

Table K-l

APPROXIMATE FLOW RATES AND VELOCITIES IN SLOPING DRAINS

(FOR FAIRLY ROUGH PIPE n = 0.015)

Flowing Half Full

1/16 in./ft. slope

1/8 in./ft. slope

1/4 in./ft. slope

1/2 in./ft. slope

Actual inside
diameter of
pipe - inches

Flow
Rpm

Vel.
fps

Flow

Vel.
fps

Flow
KPm

Vel.
fps

Flow
gpm

Vel.
fps

1.250

2.40

1.25

3.40

1.77

1.375

3.10

1.35

4.38

1.91

1.500

3.90

1.41

5.52

1.99

1.625

4.83

1.50

6.83

2.12

8.41

1.73

11.9

2.44

17.5

1.60

24.8

2.26

35.0

3.20

26.7

1.36

37.7

1.92

53.4

2.72

75.5

3.84

48.4

1.58

68.4

2.23

96.8

3.16

137

4.47

78.7

1.79

111

2.53

157

3.57

223

5.05

169

2.17

240

3.06

339

4.33

479

6.13

307

2.51

435

3.55

615

5.02

869

7.10

500

2.84

707

4.01

999

5.67

1413

8.02

906

3.29

1281

4.66

1812

6.59

2563

9.32

2006 National SianJurJ Plumbing Code-llIustmteJ

443

Table K-2
APPROXIMATE FLOW RATES AND VELOCITIES IN SLOPING DRAINS

(FOR SMOOTH PIPE n = 0.011)
Flowing Half Full

Actual inside
diameter of
pipe - inches

1/16 in./ft. slope

1/8 in./ft. slope

1/4 in./ft. slope

1/2 in./ft. slope

Flow
RPm

Vel.
fps

Flow
Rpm

Vel.
fps

Flow
gpm

Vel.
fps

Flow
gpm

Vel.
fps

1.250

3.27

1.71

4.63

2.42

1.375

4.22

1.84

5.97

2.60

1.500

5.32

1.92

7.53

2.72

1.625

6.86

2.04

9.32

2.89

11.5

2.35

16.2

3.33

23.9

2.18

33.8

3.08

47.8

4.36

36.4

1.85

51.5

2.62

72.8

3.71

103

5.24

66.0

2.15

93.3

3.05

132

4.31

187

6.09

107

2.44

152

3.44

215

4.87

303

6.89

231

2.95

327

4.18

462

5.91

654

8.36

419

3.42

593

4.84

838

6.84

1185

9.68

681

3.87

964

5.47

1363

7.73

1927

10.94

1236

4.49

1747

6.35

2471

8.99

3495

12.71

•

444

2006 National Standard Plttrnhim; Cotie-lltustraleJ

Appendix L

n Acceptable Brazing
rocedure for General

lumbin

2006 National Standard Plumbing Code-Illitstraied

445

The following is extracted and edited with permission from Chapter VII of The Copper Tube Handbook
published by the Copper Development Association. This brazing procedure is acceptable for general
plumbing work. Refer to NFPA 99 or NFPA 99 C for brazing medical gas piping.

Introduction

Strong, leak-tight brazed connections for copper tube may be made by brazing with filler metals which melt at
temperatures in the range between 1 100 F and 1500 F, as listed in Table 12. Brazing filler metals are sometimes
referred to as "hard solders" or "silver solders." These confusing terms should be avoided.

The temperature at which a filler metal starts to melt on heating is the solidus temperature; the liquidus tempera-
ture is the higher temperature at which the filler metal is completely melted. The liquidus temperature is the
minimum temperature at which brazing will take place.

The difference between solidus and liquidus is the melting range and may be of importance when selecting a filler
metal. It indicates the width of the working range for the alloy and the speed with which the alloy will become
fully solid after brazing. Filler metals with narrow ranges, with or without silver, solidify more quickly and, there-
fore, require more careful application of heat. The melting ranges of common brazing metals are shown in Figure
8a.

Brazing Filler Metals

Brazing filler metals suitable for joining copper tube are of two classes:

(1) alloys that contain phosphorus (the BCuP series) and

(2) alloys containing a high silver content (the BAg series)

The two classes differ in their melting, fluxing and flowing characteristics and this should be considered in selec-
tion of a filler metal. (See Table 12.) For joining copper tube, any of these filler metals will provide the necessary
strength when used with standard solder-type fittings or commercially available short-cup brazing fittings.

Fluxes

The fluxes used for brazing copper joints are different in composition from soldering fluxes. The two types cannot
be used interchangeably.

Brazing fluxes are water based, whereas most soldering fluxes are petroleum based. Similar to soldering fluxes,
brazing fluxes dissolve and remove residual oxides from the metal surface, protect the metal from re-oxidation
during heating and promote wetting of the surfaces to be joined by the brazing filler metal.

Fluxes also provide the craftsman with an indication of temperature. If the outside of the fitting and the heat-
affected area of the tube are covered with flux (in addition to the end of the tube and the cup), oxidation will be
prevented and the appearance of the joint will be greatly improved.

The fluxes best suited for brazing copper and copper alloy tube should meet AWS Classification FB3-A or FB3-C
as listed in Table 4. 1 of the AWS Brazing Handbook. Figure 9 , illustrates the need for brazing flux with different
types of copper and copper-alloy tube, fittings and filler metals when brazing.

446 2006 National Standard Pltimhina Codf-fllusimied

Assembling

Assemble the joint by inserting the tube into the socket hard against the stop and turn if possible. The assembly
should be firmly supported so that it will remain in alignment during the brazing operation.

Applying Heat and Brazing

Step one: Apply heat to the parts to be joined, preferably with an oxy-fuel flame. Air-fuel is sometimes used on
smaller sizes. A neutral flame should be used. Heat the tube first, beginning about one inch from the edge of the
fitting, sweeping the flame around the tube in short strokes at right angles to the axis of the tube.

It is very important that the flame be in motion continuously and not remain on anyone point long enough to
damage the tube. The flux may be used as a guide as to how long to heat the tube; continue heating the tube until
the flux becomes quiet and transparent like clear water. The behavior of flux during the brazing cycle is described
in Figure 8b .

Step two: Switch the flame to the fitting at the base of the cup. Heat uniformly, sweeping the flame from the
fitting to the tube until the flux on the fitting becomes quiet. Avoid excessive heating of cast fittings.

Step three: When the flux appears liquid and transparent on both the tube and fitting, start sweeping the flame
back and forth along the axis of the joint to maintain heat on die parts to be joined, especially toward the base of
the cup of the fitting. The flame must be kept moving to avoid melting the tube or fitting.

Step four: Apply the brazing filler metal at a point where the tube enters the socket of the fitting. When the
proper temperature is reached, the filler metal will flow readily into the space between the tube and fitting socket,
drawn in by the natural force of capillar}' action.

Keep the flame away from the filler metal itself as it is fed into the joint. The temperature of the tube and fitting
at the joint should be high enough lo melt the filler metal.

Keep both the fitting and tube heated by moving the flame back and forth from one to the other as the filler metal
is drawn into the joint.

When the joint is properly made, a continuous fillet of filler metal will be visible completely around the joint. Stop
feeding as soon as you see that fillet. Table 1 1 is a guide to estimating how much filler metal will be consumed.

For 1-inch tube and larger it may be difficult to bring the whole joint up to heat at one time. It frequently will be
found desirable to use a multiple-orifice torch tip to maintain a proper temperature over large areas. A mild
preheating of the whole fitting is recommended for larger sizes. Heating then can proceed as outlined in the steps
above.

Horizontal and Vertical Joints

When brazing horizontal joints, it is preferable to first apply the filler metal at the bottom, then the two sides, and
finally the top, making sure the operations overlap. On vertical joints it is immaterial where the start is made. If
the opening of the socket is pointing down, care should be taken to avoid overheating the tube, as this may

200(i National Standard Plumbing Codc-Illitstraied

447

cause the brazing filler metal to run down the outside of the tube. If this happens, take the heat away and allow
the filler metal to set. Then reheat the cup of the fitting to draw up the filler metal.

Removing Residue

After Lhe brazed joint has cooled the flux residue should be removed with a clean cloth, brush or swab using
warm water. Remove all flux residue to avoid the risk of the hardened flux temporarily retaining pressure and
masking an imperfectly brazed joint. Wrought fittings may be cooled more readily than cast fittings, but all fittings
should be allowed to cool naturally before wetting.

General Hints and Suggestions

If the filler metal fails to flow or has a tendency to ball up ? it indicates oxidation on the metal surfaces or insuffi-
cient heat on the parts to be joined. If the tube or fitting start to oxidize during heating there is too little flux. If the
filler metal does not enter the joint and tends to flow over the outside of either member of the joint, it indicates that
one member is overheated or the other is under heated.

Testing

Test all completed assemblies for joint integrity. Follow the testing procedure prescribed by applicable codes
governing the intended service.

Table 12.Filler Metals for Brazing

AWS
Classification 1 j

Principal Elements j

Temperature F j

Silver |

Phosphorus \

Zinc I Cadmium ;

Tin

Copper

Solidus 1 Liquidus \

BCup-2 [

, I

7.00-7.5

_:;JL_-\ :

Remainder

1310 M 1460 \

BCup-3

4.8-5.2 1

5.8-6.2

- :

Remainder

1190 1495 \

BCup-4

5.8-6.2 I

7.0-7.5

— - ™

.... ■

Remainder

1190 1

1325 1

j BCup-5 J

14.5- 1 5.-5 f

4.8-5.2 >

_ J^J

Remainder

1190

1475 ]

| BAg-P J

i
44-46 {

_,J

14- IS j

23-25*

- ;

14-16
25-27 I

1125 f

1145 j

BAg-2 1 !

34-36 1

19-23 f

J7-19 2

1 125 i

1295 \

BAg-5 j

44-46 ]

23-27 j

29-31

1225 [] 1370 |

BAg-7^ _ j

55-57 |

15-19' j

4.5-5.5 :

2.1-23 i

1145 j 1205 j

' ANSI/AWS A5.8 Specification for Filler Metals lor Brazing

2 WARNING: BAgl and BAg2 contain cadmium. Heating when brazing can produce highly toxic fumes.

CAUTION: Avoid breathing fumes - use adequate ventilation. Refer to ANS1/ASC Z49. 1 Safety in Welding and dating.

448

2006 National Standard Piumhii:^ Code-llhnnwed

Figure 8. Melting Temperature Ranges for Copper and Copper Alloys, Brazing Filler Metals,
Flux and Solders

8a.

tSOOF

^J^>

1000 F

; ;^~

MaUNG BASSE
1 831, Copper

1810*1880, Red Brass

16&M71G, V«fi0W Brass

BRAZiMQ TEMPERATURE RABSI
1350-1550, 6C»P-2 Ccppsi Ptas.
laW-l^Q, BCuP-3 Copper p!*S5.
1300-1450. BCuP-4 Copper Pte&
1300-1500, BCuP~5 Copf»rf%£^,
1145-1400, BAg-1 Silver
1295-1559. BAg-2 S&$r
1370-1550, BAg-5 S&er
1205*1400. BA0-7 Sliver

MELTING ft*N6g-69U$R$
452-4R $5-5 Tp-Astoftny
361-421,50-50 BrRgaci

8b,

2880 F

tSOOf

§00?

PfctecitoHers

Stai«&ftJBr82i»9 Ffcxas
Protect !to Here

Bux Cleaf and Mel

^1— flp Begins to MeK
flux BubWm

Room Temperature

2006 National Standard Phunbiny Codc-Htiisimied

449

Figure 9. Brazing Flux Recommendations

&0FHP£ft

ctm

WROUGHT 8Ag

CAST

450

2006 Nauounl Standard Plumbing Code-Jllustraied

Table 11. Typical Brazing Filler Metal Consumption

i-^SWsr-S^- *4K* ■«

Tube, |

nominal !

or j

standard j

size, i

inches ,

Filler Metal Length, inches

1/16 inch
wire

1/8 inch x 0.050
inch rod

3/32 inch
wire

1/8 inch
wire

Average
weight per
100 joints,

pounds 1

3 7,

4 7;

l'/ 4

3
4'

2 7*

6 %

5 /«

J. 22

S 7,

7 7,

4 7,

1.64

1 1 %

10%

14%
22%

7r%

53 7,"

20 7,

11%

I 28 %

67%

48 7j
61

27%
34 %

2 18

2 81

4.30

5 97

10 20

12.77

90 %

46%

17.20

Footnote 1

The amount of filler material indicated is based on an average two-thirds penetration of the cup and with no provision
for a fillet. For estimating purposes, actual consumption may be two to three times the amounts indicated in this table,
depending on the size of the joints, method ofapplication and leve! of workmanship.

NOTE:

1090 inches of 1/16 inch wire = I pound

534 inches of 1/8 inch x .050-inch wire = 1 pound

484 inches of 3/32 inch wire = 1 pound

268 inches of 1 /8 inch wire = 1 pound

2006 National Standard Plumbing Code-Illustrated

451

Blank Page

452 200f> National Standard Plumbing Code-Illustrated

•

Alphabetical Index

Accessible:

Definition of, 1 .2

Backflow preventers, 10.5.5

Backwater valves, 5.5.2

Expansionjoints, 4. 1 .3

Fixture, appliance and equipment
valves, 10.12.4.a

Flushometer valves, 7.1 9.5

Liquid waste treatment equipment, 6. 1 .6

Sump pits, 1 1.7.1

Valves in multi-dwelling units, 10.12.4.d

Water hammer arrestors, 10.14. 7. c

Water supply control valves, 1 0. 12.9
Adopting Agency:

Definition of, 1.2
Authority Having Jurisdiction:

Definition of, 1.2

Requirements for, Appendix F
Air Break:

Definition of, 1.2

Air conditioning equipment, 9.1.10

Commercial dishwashing machines, 7.15.4

Drinking fountains, 9. 1 .9

Food handling areas, 9. 1 .5

Potable clear water wastes, 9.1.8

Walk-in coolers, 9. 1 .6

Walk-in freezers, 9.1.6
Air Chambers:

Definition of, 1.2
Air Gap (drainage):

Definition of, 1.2

Air conditioning equipment, 9.1.10

Aspirators, 14.13

Bedpan steamers, 14.10.2

Commercial dishwashing machines, 7. 1 5.4

Drain outlets, 9.1.2

Drinking fountains, 9. 1.9

Drinking water treatment units, 7.22, 1 0. 1 8.2

Food handling areas, 9. 1 .5

Indirect waste pipes, 9. 1 .2

Medical equipment, 9. 1 .7

Minimum for fixtures, Table 1 0.5.2

Potable clear water wastes, 9.1.8

Relief valve discharge piping, 1 0. 1 6.6.d

Sterilizers, 14.10.2

Swimming pools, 9. 1 . 1 1
Air Gap (water distribution):

Definition of, 1 .2

Automatic clothes washers, 7.13.1

Below rim supply to tank or vat, 10.5.7

Domestic dishwashers, 7.15.1

Over-rim tub filler spout, 7.8.4

Requirements for, 10.5.2
Anchors;

See Supports
Anti-scald valve:

See Water Temperature Control Valve
Approval of Alternate Materials:

Requirements for, 3.12
Approval:

Definition of, 1.2
Area Drain:

Definition of, 1.2
Aspirator:

Definition of, 1.2
Backfilling:

Requirements for, 2.6.3, 2.6.4
Backflow (drainage):

Definition of, 1 .2
Backflow (water distribution):

Definition of, 1.2
Backflow Preventers:

Definition of, 1 .2

Approval of, 10.5.4

Installation of, 10.5.5

Maintenance and testing of, 10.5.6

Required types, 10.5.3

Standards for, Table 3. 1 .3 Part IX
Backflow Prevention:

Appliances, 10.5.1

Carbonated beverage dispensers, 10.5.8

Domestic water heat exchangers, 10.5.1 1

Fire protection systems, 10.5.9

Hose connections, 10.5.12

2006 National Standard Plumbing Code-Illustrated

453

Irrigation systems, 10.5.10

Lawn sprinklers, 10.5.10

Plumbing fixtures, 10.5.1

Special equipment, 1 0.5. 1 3

Tanks and vats, 10.5.7

Water supply outlets, 10.5.1
Backpressure backflow:

Definition of, 1 .2
Back Siphonage:

Definition of, 1 .2
Backwater Valve:

Definition of, 1 .2

Posted notice, 5.5.3
Baptistries:

Backflow protection, 7. 1 8
Bar Sinks:

Requirements for, 7.1 1 .2
Basic Design Circuit (BDC):

Explanation of, B.9.3
Bathroom Group:

Definition of, 1.2

Drainage fixture units (DFU), Table 1 1.4.1

Stack venting, 12.1 1

Water supply fixture units (WSFU), Table

10.14.2.A

Wet venting, 12.10
Bathtubs:

Requirements for, 7.8
Battery of Fixtures:

Definition of, 1 .2
Bedding

Under pipes in trenches, 2.6.1
Bidets:

Requirements for. 7.7
Branch Interval:

Definition of, 1.2
Building Classification:

Definition of, 1.2
Building Sanitary Drain:

Definition of, 1.2

Materials, 3.5.2

Required size, Table 1 1 .5. 1 .A
Building Storm Drain:

Definition of, 1.2

Materials, 3.7.3

Required size, 13.6.2
Building Sanitary Sewer:

Definition of, 1.2

Materials, 3.5.3

Required size, Table 1 1 .5. 1 .A

Separation from water service, 10.6.1
Building Storm Sewer:

Definition of, 1 .2

Materials, 3.7.4

Required size, 13.6.2
Building Subdrains:

Definition of, 1 .2

Sump pits and pumps, 1 1 .7

Venting, 11.7.4
Building Traps:

Definition of, 1 .2

Where required, 5.3.4
Cesspool:

Definition of, 1.2
Chemical Waste:

See Special Wastes

Treatment of, 9.4.1
Cleanouts:

At base of stacks, 5.4.5

At junction of bldg drain and bldg sewer, 5.4.6

Direction of opening, 5.4.7

In building sewers, 5.4.2

In concealed piping, 5.4.4

Manholes, 5.4. 10

Prohibited connections to, 5.4.8

Required size, 5.4.9

Spacing, 5.4.1
Clear Water Wastes:

Definition of, 1 .2
Clinical Sinks:

Definition of, 1.2

Local vents for, 14.9

Requirements for, 14.8.1
Clothes Washers:

Required compliance, 7.13
Code:

Definition of, 1.2
Combination Fixtures:

Definition of, 1.2
Combination Waste and Vent Systems:

Definition of, 1 .2

Requirements for, 12.17
Conductors (storm water):

Definition of, 1 .2

Connection to combined sewer, 13.4.3

Improper use, 13.4.1

Required size, 13.6.1

454

20D6 National Smndnrrt Plumbing Cnde-lllustmiecl

Continuous or Intermittent Drain Flow:

Conversion to DFU, 1 1 .4.2
Corrosive Fill:

Protection of pipes, 2.9.2
Corrosive Wastes:

Treatment of, 9.4. 1
Critical Level:

Definition of, 1 .2

Of backflow preventers, 10.5.5
Cross Connection:

Definition of, 1.2

Control, 10.4.3
Cross Connection Control

Program for, 10.4.3
Cutting and Notching:

Structural members, 2.9.3
Day Care Center:

Definition of, 1 .2
Day Nursery:

Definition of, 1.2
Dead Ends:

Definitions, 1 .2

Avoidance, 2.23
Decorative Fountains:

Backflow protection, 7. 1 8
Defective Plumbing:

Testing or inspecting, 1 5.7
Definitions:

Code terms, Chapter 1

Mobile home park, 1 8. 1

Travel trailer park, 1 8. 1
Demand (water):

Estimating procedure, B.5

Sizingpiping, 10.14.3
Developed Length:

Definition of, 1.2
Diameter:

Definition of, 1.2
Dilution Tanks:

Requirements for, 6.6
Directional Changes:

In drainage piping, 2.3
Discharge Rates:

In sloping drains, Appendix K
Dishwashing Machines:

Requirements for, 7. 1 5
Disinfection:

Of potable water systems, 10.9

Disposal Fields:

Size and spacing, 16.9.3
Distribution Box:

For individual sewage disposal system, 1 6.9
Domestic Sewage

Definition of, 1 .2
Double Check Valve Assembly

Definition of, 1 .2

Installation of, 10.5. 5.d

Maintenance of, 10.5.6

Testing of, 10.5.6

Where required, 10.5.3
Downspout (rain water):

See Leader
Drainage Fixture Unit (DFU)

See Fixture Unit, Drainage
Drainage Piping:

See Drainage System
Drainage System:

Definition of, 1 .2
Drainage System, Building Gravity:

Definition of, 1.2
Drainage System, Sanitary

Branch connections (near base of stacks), 1 1 .9

Branch connections (to offsets), 11.10

Building sewers, 1 1.2

Ejectors and pumps, 1 1 .7

Fixture units (DFU), 1 1 .4

Offsets in piping, 1 1 .6

Pipe sizing, 11.5

Piping materials, 3.5

Slope of piping, 1 1.3.1

Suds pressure zones, 11.11

Sump pits, 1 1.7
Drainage System, Storm:

Airconditioningcondensate, 13.8

Areaway drains, 13.1.6

Backwater valves, 13.1.12

Combined sewer, 13.4.3, 13.4.4

Continuous flow, 13.1.1 1

Controlled flow system, 13.9

Foundation drains, 13.1.5

Parking garages, 13.1.8

Pipe sizing, 13.6

Piping materials, 3.7

Prohibited connections, 13.1.2

Protection of leaders, 13.4.2

Roof drainage, primary, 13.1.10.1

Roof drainage, secondary, 13.1.10.2

2(106 Mariana/ Standard Plumbing Code-Uhisiraied

455

Roof drains, 13.5

Service garages, 13.1.8

Sewers, 13.1.3

Traps, 13.3

Vertical walls, 13.1.10.3

Window well drains, 13.1.7
Drinking Fountains:

Compliance, 7. 12.1

Indirect waste discharge, 9.1.9

Prohibited locations, 7. 1 2.2
Drinking Water Facilities:

Required number of: Table 7.2 1 . 1
Dry Well:

Definition of, 1 .2
DWV (drain-waste-vent):

Definition of, 1.2
Effective Opening:

Definition of, 1 .2
Ejector (sewage):

Building subdrains, 1 1.7.1

For individual fixtures, 1 1 .7.9

Grinderpumps, 1 1 .7.6

High water alarms, 1 1 .7. 1 1

Macerating toilet systems, 1 1 .7.10

Pneumatic, 1 1 .7.7

Requirements for, 1 1 .7.8

Sump pits, 1 1.7.1

Venting subdrains, 1 1 .7.4
Equipment:

Condemned, 2.15

Used, 2.14
Equivalent Length:

Definition of, 1.2

Of valves and fittings, B.9.7
Erosion (pipe):

Corrosion, B. 6. 3
ExistingBuildings:

Code compliance, 3.12.1
Existing Work:

Definition of, 1 .2
Expansion Joints:

Access to, 4.1.3
Exposure of Work:

For testing and approval, 1 5. 1
Family:

Definition of, 1 .2
Ferrous Pipe and Fittings:

Standards, Table 3.1.3, Part 1

Filter (sewage):

See Sand Filter
Fixtures (plumbing):

Definition of, 1 .2

Accessible use, 7.2

Access for cleaning, 7.3.3

Access for use, 7.21.3

Air gaps for, 10.5.2

Automatic clothes washers, 7.13

Back-to-back, 2.3.3

Bathtubs, 7.8

Bidets, 7.7

Circular wash fountains, 7.6.5

Clearances required,

Combination bath/showers,

DFU load values, 11.4

Dishwashing machines, 7.1 5

Drinking fountains, 7. 1 2

Emergency eyewash stations, 7.24

Emergency showers, 7.24

Floor drains, 7.16

Flushingdevices, 7. 1 9

Food Waste Grinders, 7. 1 4

Garbage can washers, 7.17

Group-type wash fountains, 7.6.5

Group-type wash sinks, 7.6.5

In correctional institutions, 7.20

In detention centers, 7.20

In facilities serving customers, 7.2 1 .7

In food service areas, 7.21.8

In special occupancies, 7.21.6

Installation of, 7.3

Lavatories, 7.6

Minimum number of, 7.21

Occupant load for. 7.2 1 .2

Omission of, 7.21 .5

Prohibited urinals, 7.5.4

Prohibited water closets, 7.4.7

Separate toilet facilities, 7.2 1 .4

Showers, 7.10

Sinks,7.11

Spa and hot tub safety, 7.23

Special installations, 7. 1 8

Substitution of, 7.21.5

Standards for, 7.1

Trench drains, 7.16

Urinals, 7.5

Water closets, 7.4

456

2006 Notional Standard Plumbin? Code-Illustrated

Water coolers, 7.12

Water treatment systems, 7.22

Whirlpool baths, 7.9

WSFU load values, Table 10.4.2. A
Fixture Branch (drainage):

Definition of, 1 .2

Minimum size underground, 1 1 .5.5

Sizing, 11.5.3
Fixture Drain:

Definition of, 1.2
Fixture Supply Branch:

Definition of, 1.2

Flow rates for sizing, 1 0. 1 4.2

Minimum size, 10.14.2
Fixture Traps:

General requirements, 5.3

Separate for each fixture, 5.1

Size, 5.2
Fixture Unit (drainage DFU):

Definition of, 1.2

Converting GPM to DFU, 1 1 .4.2

For bathroom groups, Table 1 1 .4. 1

For individual fixtures, Table 1 1 .4. 1
Fixture Unit (water supply WSFU):

Definition of, 1 .2

Converting WSFU to GPM, Table 10.14.2.B

For bathroom groups, Table 1 1.14.2.A

For individual fixtures, Table 11.1 4.2.A

For kitchen groups, Table 1 1.1 4. 2. A

For laundry groups, Table 1 1.1 4. 2. A
Flashing:

Roof drains, 13.5.4

Vent terminals, 12.4.2

Vent through roof, 4.5
Flood Level Rim:

Definition of, 1 .2
Flooded;

Definition of, 1.2
Floor Drains:

Requirements for, 7.16
Floor Flanges:

For water closets, 3.3.4

Water closet connections, 2.22
Flow Pressure:

Definition of, 1.2
Flow Rates (drainage):

In sloping drains, Appendix K
Flow Rates (water):

Based on pressure drop, Table B.9.8

Based on velocity, Tables B.7.3

For fixtures, 10.14.2
Flushing Devices:

Flush tanks, 7. 19.3

Flushometer tanks, 7. 19.4

Flushometer valves, 7. 1 9.5
Food Handling Areas:

Indirect wastes, 9.1 .5

Requirements for, 2.25
Food Waste Grinders:

Into grease interceptor, 6.2.3

Requirements for, 7.14

With sink and dishwasher, 7. 1 5.3
Footings:

Protection of, 2.17
Foul Air:

Exhaust, "B"P-No. 12
Freezing:

Protection from, 2.16
Friction Loss Allowance

Pipe, tube, and fittings, B.9.7
Frost Closure:

Vent terminals, 12.5
Garage Can Washers:

Requirements for, 7.17
Grade:

Definition of, 1 .2
Graywater Recycling Systems:

Requirements for, Appendix G
Grease Interceptors:

Requirements for, 6.3
Grease Recovery Devices (GRD):

Requirements for, 6.3
Ground Water:

Definition of, 1.2

Protection of, BP No. 22
Hangers (pipe):

Requirements for, Chapter 8
Health Care Facilities:

Aspirators, 14.13

Bedpan Washers, 14.8

Central vacuum systems, 14.12

Clinical sinks, 14.8

Local vents and stacks, 14.9

Medical gas and vacuum systems, 14.3

Mental patient rooms, 14.5

Prohibited locations for ice storage, 14.6

2006 Matronal Standard Plumbing Code-flliMraied

457

Protrusions from walls, 14.4

Special requirements for, Chapter 14

Sterilizers, 14.10

Vapor vents and stacks, 14.1 1

Water service, 14.2
Health Hazard:

Definition of, 1 .2

Abatement of, 2.5
Horizontal Branch Drain:

Definition of, 1.2
Horizontal Pipe:

Definition of, 1 .2
Hot Water:

Definition of, 1 .2

Mixed water temperature control, 10.15.6

Plastic piping, 10.15.8

Temperature maintenance, 1 0. 1 5.2

Thermal expansion control, 1 0. 1 5.7

Where required, 10.15.1
Indirect Waste Connections:

Definition of, 1.2

Air conditioning equipment, 9. 1 . 1

Drinking fountains, 9. 1 .9

Fixture traps, 9.2.3

Food handling areas, 9. 1 .5

Medical equipment, 9. 1 .7

Piping, 9.2

Potable clear water waste, 9.1.8

Receptors, 9.3

Requirements for, 9.1

Sterile equipment, 9. 1 .7

Swimming pools, 9.1.11

Walk-in coolers, 9.1.6

Walk-in freezers, 9. 1 .6

Water coolers, 9.1 .9
Indirect Waste Pipe:

Definition of, 1.2

Materials, 9.2.1

Size, 9.2.2
Indirect Waste Receptors:

DFU values, 9.3.7

Minimum pipe size, 9.3.6

Open-hub drains, 9.3.5

Prohibited locations, 9.3.3

Standpipes, 9.3.4

Strainers or baskets, 9.3.2
Industrial Waste:

Definition of. 1.2

Insanitary:

Definition of, 1 .2
Installation Practices:

Plumbing systems, 2.8
Installed:

Definition of, 1 .2
Interceptor:

Definition of, 1.2
Invert:

Definition of, 1.2
Laundry Sinks:

Requirements for, 7.11.3
Lavatories:

Minimum number required, Table 7.2 1 . 1

Requirements for, 7.6
Leaders (rain water):

Definition of, 1 .2

Requirements for, 13.4

Sizing of, 13.6
Local Ventilating Pipe:

Definition, 1 .2
Main:

Definition, 1 .2
Manholes:

Requirements for, 5.4. 10
May:

Definition, 1 .2
Metric Conversion:

Tables, Appendix C
Mixed Water Temperature Control:

Requirements for, 1 0. 1 5.6
Mobile Home Parks:

Requirements for, Chapter 1 8
Multiple Dwelling:

Definition, 1 .2
Neutralizing Tanks:

Requirements for, 6.6
Non-potable Water:

Definition, 1 .2
Nuisance:

Definition, 1 .2
Obstruction to Flow:

Drainage, 2.4.3
Offset:

Definition, 1 .2
Offsets (drainage piping)

Sizing, 1 1 .6
Oil/Water Separators:

Requirements for, 6.3

458

2006 National Standard Plmnbins Code-Illustrated

Overflows:

Lavatories, 7.6.4

Flush tanks, 7.1 9.3. d

Water supply tanks, 10.8.3
Ornamental Fountains

Backflow protection, 7. 1 8
Percolation Test:

Individual sewage disposal systems, 1 6.5
Pipe Joints:

Bending,4.2.19

Brazed, 4.2.8

Burned lead, 4.2.10

Butt fusion, 4.2. 18

Caulked, 4.2. 12

Cement mortar, 4.2.9

Different materials, 4.3

Expansion, 4.2. 16

Flared, 4.2.5

Mechanical, 4.2.1 1

Mechanically formed tee, 4.2.8.3

Mechanically crimped, 4.2.6

In plastic pipe, 4.2. 14

Push on, 4.2.7

Slip,4.2.15

Soldered, 4.2.4

Splitcouplings,4.2.17

Threaded, 4.2.2

Wiped,4.2.3
Piping Materials:

Air conditioning condensate, 3.9

Chemical wastes, 3.1 1

Combustion equipment drains, 3. 1

Foundation drains, 3.8

Potable water, 3.4

Sanitary drainage, 3.5

Special waste, 3.1 1

Storm water, 3.7

Subsoil drains, 3.8

Vents, 3.6
Plumbing:

Definition, 1 .2
Plumbing Appliance:

Definition, 1 .2
Plumbing Appurtenance:

Definition, 1.2
Plumbing Fixture:

Definition, 1.2
Plumbing Inspector:

Definition, 1 .2

Plumbing System:

Definition, 1 .2
Pollution:

Definition, 1 .2

Water service near sources of, 10.6.2
Potable Water:

Definition, 1 .2
Pressure Balancing Valve:

Definition, 1.2
Prevent Contamination:

From sewage, BP No. 1 5
Private Sewage Disposal System:

Definition, 1 .2

Requirements for, Chapter 1 6
Private Sewer:

Definition of, 1 .2
Private Water Supply:

Definition of, 1.2
Prohibited Valves:

Underground stop & waste, 10.6.3
Public Sewer:

Definition of, 1 .2
Public Toilet Room:

Definition of, 1.2
Public Water Main:

Definition of, 1 .2
Public Sewer

Definition of, 1.2

Availability, 2. 19.1

Basic principle, BP No. 6
Public Water Main:

Definition of, 1.2

Availability, 2. 19.1

Interconnections, 10.4.2
Rainfall Rates:

Appendix A
Readily Accessible:

Definition, 1 .2
Reduced Pressure Backflow Preventer:

Definition, 1.2

Installation of, 10.5. 5.d

Maintenance of, 10.5.6

Testing of, 10.5.6

Where required, 10.5.3
Rim:

Definition, 1 .2
Riser:

Definition, 1.2

2006 National Standard Plumbing Code-lllasiraied

459

Roof Drains:

Definition, 1 .2

Requirements for, 13.5
Roof Gutters:

Sizing, 13.6.3
Roughing-in:

Definition of, 1.2
Safety Devices:

Combination P&T relief valves, 10.16.4

Pressure relief valves, 10.16.2

Relief valve discharge piping, 1 0. 1 6.6

Replacement of relief valves, 10.16.8

Temperature relief valves, 10.16.3

Thermal expansion control, 10.15.7

Vacuum relief valves, 10.16.7
Sand Interceptors:

Requirements for, 6.4
Sanitary Sewer:

Definition of, 1 .2
Seepage Pits:

Absorption area for, 16.5.6

Where contemplated, 16.5.5
Septic Tanks:

Definition of, 1.2

Capacity of, 16.6

Location of, 16.4.4
Sewage:

Definition of, 1.2
Sewage Disposal Systems:

Private, Chapter 1 6
Sewage Ejectors, Pneumatic:

Definition of, 1 .2

Vents, 11.7.7
Sewage Pumps:

Definition of, 1.2

Requirements for, 1 1 .7
Sewage Systems:

Private, 2.19.2
Shall:

Definition of, 1.2
Shock Arrestor:

Definition of, 1 .2

Water hammer, 10.14.7
Showers:

Floors or receptors, 7.10.6

Minimum number required, Table 7.21.1

Mixed temperature control, 7. 1 0.3

Shower compartments, 7.10.5

Supply riser support, 7. 1 0.7

Waste outlet size, 7.10.4

Water conservation, 7.10.2
Sinks:

Bar sinks, 7.11.2

Bedpan washers, 14.8.1

Clinical sinks, 14.8.1

Compliance, 7.1 1.1

Faucets, 7.1 1.5

Kitchen sinks, 7.11.2

Laundry sinks, 7.11.3

Mop receptors, 7.1 1 .4

Service sinks, 7.1 1 .4
Sizing the Building Water Supply System:

Appendix B
Slaughterhouses:

Drainage in, 6.7.3
Sleeves:

Pipe, 2. 12
Slope:

See Grade
Soil Pipe:

Definition, 1 .2
Soil Stack:

Definition, 1 .2
Solids Interceptors:

Requirements for, 6.5
Special Design Plumbing Systems:

Appendix E
Special Wastes:

Definition, 1 .2

Drain piping, 3.1 1.1

Treatment of, 9.4.1

Ventpiping, 3.1 1 .2
Stack (drainage):

Definition, 1 .2

Size reduction, 1 1.5.7
Stack Vent:

Definition, 1 .2

Where required, 1 2.3. 1 .a
Standard Dimensional Ratio (SDR):

Definition of 1.2

In plastic drainage piping, 3.5.4
Sterilizers:

Drainage of, 14.10

Vapor vents and stacks, 14.1 1
Storm Sewer:

Definition, 1.2
Storm Water Drainage:

Paved areas, 13.1.1

460

.006 National Standard Plumbing Code- Illustrated

Strainers (for indirect waste):

Where required, 9.3.2
Subsoil Drain:

Definition, 1 .2
Suds Pressure Zones:

Branch connections within, 11.11.1

Exceptions to, 1 1.1 1.4

Location of zones, 1 1 . 1 1 .2

Relief vents for, 12.15

Separate stacks, 11.11.3
Sump Pump:

Definition, 1 .2

Air conditioning condensate flow, 13.8

For foundation drains, 1 3. 1 .5.d
Sumps, Drainage (sewage):

Definition, 1 .2

Venting, 12.14.2
Supports:

Definition, 1 .2

Hangers and Supports, Chapter 8
Swimming Pools:

Definition of, 1.2

Backflow prevention, 7. 1 4
Tanks:

Dilution, 6.6

Flush tanks,

Flushometer tanks,

Hot water, 3.3.8

Neutralizing, 6.6

Septic, 3.3.1 1,16.6

Waste oil, 6.3
Tempered Water:

Definition, 1 .2
Thermal Expansion Control:

For domestic hot water, 10.15.7
Toilet Facilities:

Definition, 1 .2

For construction workers, 2.24

Minimum number required, Table 7.2 1 .
Toilet Rooms:

Requirements for, 2.20
Trap Arms:

Definition, 1.2

Maximum length of, 12.8.1
Trap Seal:

Definition, 1.2

Required depth, 5.3.2
Traps:

Definitions, 1.2

Design, 5.3.1

Level setting, 5.3.3

Protection from freezing, 5.3.3

Required size, 5.2
Travel trailer Parks:

Requirements for, Chapter 1 8
Trenching:

Bedding, 2.6.1

Copperpiping, 2.6.7

Final backfill, 2.6.4

Initial backfill, 2.6.3

Plasticpipe,2.6.6

Requirements for, 2.6. 1

Safety, 2.6.8

Side fill, 2.6.2

Supervision, 2.6.9
Trenchless Pipe Replacement

Requirements for, 2.6.10
Tunneling:

Pipe installation, 2.6.5
Urinals:

Compliance, 7.5.1

Prohibited types, 7.5.4

Surrounding surfaces, 7.5.3

Water conservation, 7.5.2
Vacuum Breakers:

For backflow prevention, 10.5.3

For lawn sprinkler systems, 1 0.5. 1

For hose connections, 10.5.12

For irrigation systems, 10.5.10

For special equipment, 10.5.13

Installation of, 10.5.5

Maintenance of, 10.5.6

Testing, 10.5.6
Vacuum Systems:

Draining, 14.12
Valves:

Access to, 10.12.9

Anti-scald, 10.15.6

Backwater, 5.5

Building, 10. 12.2

Curb, 10.12.1

Double check, 10.5.3

Flushometer, 7. 19.5

Forindividual fixtures, 1 0. 1 2.6

In dwelling units, 1 0. 1 2.4

Mixed water temperature, 10.15.6

P&T relief, 10.16.4

Pressure reducing. 10.14.6

2006 National Standard Plumbing Code- Illustrated

461

Pressure relief, 10.16

Riser shutoff, 10.12.5

Temperature relief, 10.16

Water heater shutoff, 1 0. 1 2.7
Velocity Limitations:

In copper tubing, B.6.3

In water piping, 10.14.1
Vent Piping Systems:

Aggregate size of terminals, 12.16.6

Circuit venting, 12.13

Combination waste & vent, 12.17

Common vents, 12.9

Extension above roofs, 12.4.1

Extensions outside ofbuildings, 12.4.6

Fixture reventing, 12.12

Fixtures connected at different levels, 12.9.2

For building subdrain systems, 12.14

For horizontal stack offsets, 12.3.3

For pneumatic sewage ejectors, 12.14.3

For sump pits, 12.14.2

Frost closure, 12.5

Height of connections, 12.6.3

Island sink venting, 12.18

Individual vents, 1 2.9. 1

Length of vents, 12.16

Location of vent terminals, 12.4.4

Loop venting, 12.13

Materials, 3.6

Other designs, 12.19

Pipe size, 12.16

Pipe slope, 12.6.1

Prohibited use, 12.3.6, 12.4.3

Protection of trap seals, 12.2

Relief vents for stacks, 12.3.2

Sidewall venting, 1 2.4.5

Stack vent size, 12.16.4

Suds pressure venting, 12.15

Test methods, 15.4

Underground piping, 12.16.7

Vent headers, 12.16.5

Vent stack size, 12.16.4

Vent washdown, 12.12.4

Waterproof roof flashings, 12.4.2

Wet venting, 12.10
Wading Pools:

Backflow prevention, 7.14
Washrooms:

Requirements for, 2.20

Waste:

Definition, 1.2

Industrial, 2. 10.2

Potable clear water, 9.1.8

Special, 9.4
Waste Pipe:

Definition, 1 .2

Sizes, 1 1.5
Water Distribution Piping:

Definition, 1 .2

Backflow prevention, 10.5

Basic design circuit (BDC), B.9.3

Control valves, 1 0. 1 2

Disinfecting, 10.9.2

Excessive pressure, 10.14.6

Flushing, 10.9.1

Identify non-potable & potable, 10.2

Inadequate water pressure, 10.14.4

Materials, 3.4

Maximum velocity, 10. 14.1 , B6

Minimum requirements for, 10.14

Pressure booster systems, 10.8

Protection of, 10.4

Sizing, 10.14.3

Variable street pressures, 10.14.5

Water hammer, 10.14.7

Water quality, 10.1

Water service, 10.6
Water Hammer:

Arrestors, 10.14.7
Water Heaters:

Drainage from, 10.15.4

Minimum requirements for, 10.15.3

Pressure marking of, 10.1 5.5

Safety devices for, 10.16

Used for space heating, 1 0. 1 5. 1
Water Pipe Friction:

Limitations, B.9
Water Pressure:

Excessive, 10.14.6

Inadequate, 10.14.4

Minimum required, 10.14.2

Minimum street, 1 0. 1 4.5
Water Pressure Booster Systems:

Requirements for, 10.8

Where required, 10.8. 1
Water Pressure Tanks:

Construction, 3.3.8

462

2006 National Standard Plmnbin" Code-Illustrated

Drains for, 10.8.6
Pressure relief, 10.8.9
Safety devices for, 3.3.10
Waterfalls:

Backflow prevention, 7.14

•

1006 National Standard Plumbing Code-f/litstmrec/ 463

NOTES

464 2006 National Standard Plumbing Code-lllusiroted

•

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