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Full text of "Minnesota Plumbing Code"

CHAPTER 4715 

DEPARTMENT OF HEALTH 

PLUMBING CODE 

4715.0100 DEFINITIONS. 

4715.0200 BASIC PLUMBING PRINCIPLES. 

471 5.0300 GENERAL REGULATIONS OF PLUMBING CONSTRUCTION. 

4715.0310 USE OF PUBLIC SEWER AND WATER SYSTEMS REQUIRED. 

4715.0320 CONFORMANCE WITH CODE. 

471 5.0330 ALTERNATE FIXTURES, APPURTENANCES, MATERIALS, AND METHODS. 

471 5.0340 HEALTH AND SAFETY. 

MATERIALS 

4715.0400 QUALITY OF MATERIALS. 

4715.0410 IDENTIFICATION OF MATERIALS. 

471 5.0420 STANDARDS FOR PLUMBING MATERIALS. 

PIPING SYSTEM MATERIALS 

4715.0500 WATER SUPPLY SYSTEMS. 

4715.0510 WATER SERVICE PIPE . 

4715.0520 WATER DISTRIBUTION PIPE. 

4715.0530 BUILDING SEWERS. 

471 5.0540 STORM WATER AND YARD DRAINAGE (OUTSIDE FOUNDATION WALLS). 

471 5.0550 STORM WATER OR CLEAR WATER DRAINAGE (WITHIN BUILDINGS UNDERGROUND). 

471 5.0560 STORM WATER OR CLEAR WATER DRAINAGE (WITHIN BUILDINGS ABOVE GROUND). 

471 5.0570 SOIL AND WASTE PIPING UNDERGROUND OR EMBEDDED. 

4715.0580 SOIL AND WASTE PIPING ABOVE GROUND. 

471 5.0590 VENT PIPING BELOW GROUND. 

471 5.0600 VENT PIPING ABOVE GROUND. 

4715.0610 SPECIAL WASTES. 

4715.0620 SUBSOIL DRAINS. 

4715. 0630 SPECIAL MATERIAL S . 

4715.0640 FIXTURE MATERIALS. 



JOINTS AND CONNECTIONS 



4715.0700 TIGHTNESS. 



TYPES OF JOINTS FOR PIPING MATERIAL 

4715.0710 ASBESTOS CEMENT SEWER PIPE JOINTS. 

4715.0720 BITUMINIZED FIBER DRAIN PIPE JOINT. 

4715.0730 BURNED LEAD JOINTS. 

4715.0740 CAULKED JOINTS. 

4715.0750 CEMENT MORTAR JOINTS. 

4715.0760 COLD JOINT COMPOUND, TAR BASE. 

4715.0770 FLARED JOINTS. 

4715.0780 GASKET TYPE JOINTS. 

4715.0790 HOT-POURED JOINTS. 

4715.0800 MECHANICAL JOINTS. 

4715.0805 PUSH-ON JOINTS. 

4715.0810 PLASTIC JOINT S . 

4715.0815 JOINTS IN CHEMICAL WASTE PIPE. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



PLUMBING CODE 



4715. 0820 SOLDERED OR BRAZED JOINT S . 

4715.0830 THREADED JOINTS - SCREWED JOINTS. 

4715.0840 WIPED JOINTS. 

4715.0850 USE OF JOINTS. 

4715. 0860 SPECIAL JOINT S . 

471 5.0870 FLANGED FIXTURE CONNECTIONS. 

4715.0880 PROHIBITED JOINTS AND CONNECTIONS. 

4715.0890 INCREASERS AND REDUCERS. 



TRAPS AND CLEANOUTS 

471 5.0900 FIXTURE TRAP REQUIREMENTS. 

4715.0910 TRAPS DESCRIBED. 

471 5.0920 TRAP PROTECTION. 

4715.0930 SIZES OF TRAPS. 

4715.0940 SLIP JOINTS AND UNIONS. 

4715.0950 TRAP SEALS. 

4715. 0960 TRAP S PROHIBITED . 

4715.0970 TRAP CLEANOUTS. 

DRAINAGE PIPE CLEANOUTS 

4715.1000 LOCATION. 

4715.1010 SIZE OF CLEANOUTS. 

4715.1020 CLEANOUT MATERIALS. 

4715.1030 CLEANOUTS TO BE ACCESSIBLE. 

INTERCEPTORS, SEPARATORS, AND BACKWATER VALVES 

4715.1100 INTERCEPTORS AND SEPARATORS REQUIRED. 

4715.1110 GREASE INTERCEPTORS FOR COMMERCIAL BUILDINGS. 

4715.1115 EXTERIOR GREASE INTERCEPTORS. 

4715.1120 OIL AND FLAMMABLE LIQUIDS SEPARATOR. 

4715.1130 INTERCEPTORS AND SEPARATORS FOR SPECIFIC INSTALLATIONS. 

4715.1140 VENTING OF INTERCEPTORS AND SEPARATORS. 

4715.1150 MAINTENANCE OF INTERCEPTORS AND SEPARATORS. 

4715.1160 BACKWATER VALVES. 

PLUMBING FIXTURES 

4715.1200 CONNECTIONS TO PLUMBING SYSTEM REQUIRED. 

4715.1210 REQUIRED MINIMUM NUMBER OF FIXTURES. 

4715.1220 INSTALLATION OF FIXTURES. 

4715.1230 AUTOMATIC CLOTHES WASHERS. 

4715.1240 BATHTUBS. 

4715.1250 DISHWASHING EQUIPMENT. 

4715.1260 DRINKING FOUNTAINS. 

4715.1300 FLOOR DRAINS. 

4715.1305 ELEVATOR PIT DRAIN. 

4715.1310 FOOD-WASTE GRINDER UNITS. 

4715.1320 FLUSHING DEVICES FOR WATER CLOSETS AND URINALS. 

4715.1330 FLUSH TANKS. 

4715.1340 FLUSHOMETER VALVES. 

4715.1350 GARBAGE CAN WASHERS. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



PLUMBING CODE 



4715.1360 LAUNDRY TRAYS. 

4715.1370 LAVATORIES. 

4715.1380 SHOWERS. 

4715.1390 SINKS. 

4715.1400 SPECIAL PLUMBING FIXTURES. 

4715.1410 URINALS. 

4715.1420 WATER CLOSETS. 

HANGERS AND SUPPORTS AND PROTECTION 

4715.1430 HANGERS AND SUPPORTS. 

4715.1440 PROTECTION OF PLASTIC PIPE. 

INDIRECT WASTE PIPING 

4715.1500 INDIRECT WASTE CONNECTIONS. 

4715.1510 INDIRECT WASTE PIPING. 

4715.1520 CONNECTIONS FROM WATER DISTRIBUTION SYSTEM. 

4715.1530 STERILIZERS. 

4715.1540 POTABLE CLEAR WATER WASTES. 

4715.1550 DRINKING FOUNTAINS. 

4715.1560 SWIMMING POOLS. 

4715.1570 METHOD OF PROVIDING AN AIR GAP. 

4715.1580 METHOD OF PROVIDING AN AIR BREAK. 

4715.1590 RECEPTORS OR SUMPS. 

SPECIAL WASTES 

4715.1600 CHEMICAL WASTES. 

4715.1610 STEAM AND HOT WATER WASTES. 

WATER SUPPLY AND DISTRIBUTION 

4715.1700 WATER REQUIRED. 

4715.1710 WATER SERVICE . 

4715.1720 DESIGN OF BUILDING WATER DISTRIBUTION SYSTEM. 

4715.1730 SIZE OF FIXTURE BRANCH. 

4715.1740 WATER PRESSURE. 

4715.1750 WATER HAMMER. 

4715.1760 SUPPLY DEMAND. 

4715.1770 MINIMUM PRESSURES REQUIRED IN WATER DISTRIBUTION SYSTEM. 

INSTALLING THE BUILDING WATER DISTRIBUTION SYSTEM 

4715.1800 WATER SUPPLY CONTROL VALVES. 

4715.1810 WATER PRESSURE BOOSTER SYSTEMS. 

PROTECTION OF POTABLE WATER SUPPLY 

4715.1900 DESIGN, MAINTENANCE, AND INSTALLATION. 

4715.1910 IDENTIFICATION OF POTABLE AND NONPOTABLE WATER. 

4715.1911 TOXIC MATERIALS AND USED PIPE. 

4715.1912 USED WATER RETURN PROHIBITED . 
4715.1920 CROSS-CONNECTION CONTROL. 

4715.1940 POTABLE WATER CONNECTIONS TO HEATING OR COOLING SYSTEMS. 

4715.1941 HEAT EXCHANGERS. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



PLUMBING CODE 



4715.1950 PROHIBITED CONNECTIONS TO FIXTURES AND EQUIPMENT. 

4715.1960 REFRIGERATING UNIT CONDENSERS AND COOLING JACKETS. 

PROTECTION OF POTABLE WATER AGAINST 

BACKFLOW AND BACK-SIPHONAGE 

4715.2000 WATER OUTLETS. 

4715.2010 MINIMUM REQUIRED AIR GAP. 

471 5.2020 DEVICES OR ASSEMBLIES FOR THE PROTECTION OF THE POTABLE WATER SUPPLY. 

4715.2030 APPROVAL OF DEVICES OR ASSEMBLIES. 

INSTALLATION OF DEVICES 

4715.2100 BACKFLOW PREVENTERS. 

4715.2110 TYPES OF DEVICES REQUIRED WHERE AN AIR GAP CANNOT BE PROVIDED. 1 

4715.2120 LOCATION OF BACKFLOW PREVENTERS. 

4715.2150 CONNECTIONS NOT SUBJECT TO BACK PRESSURE. 

4715.2160 CONNECTIONS SUBJECT TO BACK PRESSURE. 

4715.2161 INSTALLATION OF REDUCED PRESSURE BACKFLOW PREVENTERS. 

4715.2162 DOUBLE CHECK - DOUBLE GATE VALVE ASSEMBLIES. 

4715.2163 CARBONATED BEVERAGE MACHINES. 
4715.2165 CHEMICAL/SOAP DISPENSING SYSTEMS. 
471 5.21 70 BAROMETRIC LOOR 

4715.2180 HOT WATER SUPPLY SYSTEM. 

4715.2190 COMBINATION WATER AND SPACE HEATING EQUIPMENT. 

471 5.2200 PRESSURE RELIEF VALVES AND TEMPERATURE RELIEF VALVES DEVICES REQUIRED. 

4715.2210 PRESSURE RELIEF VALVES. 

4715.2215 THERMAL EXPANSION CONTROL. 

4715.2220 HOT WATER STORAGE TANKS. 

4715.2230 TANKLESS AND INSTANTANEOUS TYPE HEATERS. 

4715.2240 ACCESS TO WATER HEATERS. 

4715.2250 DISINFECTION OF POTABLE WATER SYSTEM. 

4715.2280 WATER METER INSTALLATION. 

DETERMINING SIZE OF DRAINAGE SYSTEM 

4715.2300 LOAD ON DRAINAGE PIPING. 

4715.2310 SELECTING SIZE OF DRAINAGE PIPING. 

4715.2320 MINIMUM SIZE OF SOIL AND WASTE STACKS. 

4715.2330 MINIMUM SIZE OF STACK VENT OR VENT STACK. 

4715.2340 PROVISION FOR FUTURE FIXTURES. 

471 5.2350 MINIMUM SIZE OF UNDERGROUND DRAINAGE PIPING. 

4715.2360 SIZING OF OFFSETS ON DRAINAGE PIPING. 

4715.2370 FIXTURE CONNECTIONS TO AN OFFSET OF MORE THAN 45 DEGREES OR AT BASE OF 

STACK. 

DRAINAGE PIPING INSTALLATION 

471 5.2400 PITCH ON HORIZONTAL DRAINAGE PIPING. 

4715.2410 CHANGE IN DIRECTION. 

4715.2420 PROHIBITED FITTINGS AND CONNECTIONS. 

471 5.2430 BUILDING DRAINS BELOW BUILDING SEWER. 

4715.2440 DESIGN OF SUMPS. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



PLUMBING CODE 



VENTS AND VENTING 

471 5.2500 SELECTING SIZE OF VENT PIPING. 

4715.2510 PROTECTION OF TRAP SEALS. 

4715.2520 VENT STACKS AND STACK VENTS. 

4715.2530 VENT TERMINALS. 

471 5.2540 VENT GRADES AND CONNECTIONS. 

4715.2550 WET VENTING. 

4715.2560 STACK VENTING. 

471 5.2570 INDIVIDUAL FIXTURE REVENTING REQUIRED. 

4715.2580 COMMON VENTS. 

4715.2600 CIRCUIT AND LOOP VENTING. 

4715.2610 FIXTURES BACK-TO-BACK. 

4715.2620 FIXTURE VENTS. 

4715.2630 VENTS FOR FIXTURE TRAP BELOW TRAP DIP 

471 5.2640 YOKE VENTS FOR STACKS OF MORE THAN FIVE BRANCH INTERVALS. 

471 5.2650 COMBINATION WASTE AND VENT SYSTEM. 

4715.2655 ISLAND FIXTURE VENTING. 

4715.2660 VENTING OF SUMPS AND SEWERS. 

STORM DRAINS 

4715.2700 STORM SEWER SYSTEMS. 

4715.2710 SIZE OF BUILDING STORMDRAINS AND LEADERS. 

4715.2720 SUBSOIL DRAINS. 

4715.2730 BUILDING SUBDRAINS. 

4715.2740 TRAPS ON STORM DRAINS AND LEADERS. 

4715.2750 CONDUCTORS AND CONNECTIONS. 

4715.2760 ROOF AND DECK DRAINS. 

4715.2770 PROVISIONS FOR EXPANSION. 

4715.2780 CONTROL FLOW STORM WATER DRAINAGE FOR DEAD LEVEL ROOFS. 

INSPECTION, TESTS, AND MAINTENANCE 

4715.2800 INSPECTIONS. 

4715.2810 NOTIFICATIONS. 

4715.2820 METHOD OF TESTING. 

4715.2830 COVERING OF WORK. 

4715.2840 DEFECTIVE WORK. 

4715.2850 AIR TEST OF DEFECTIVE PLUMBING. 

4715. 2860 MAINTENANCE. 

4715.2870 DISINFECTION OF WATER PIPING. 

4715.2880 BUILDING SEWER. 

4715. 2890 CERTIFICATE OF APPROVAL . 

PLUMBERS AND PLUMBING; REQUIREMENTS 

4715.3130 PLANS AND SPECIFICATIONS. 

4715.3140 EXAMINATION AND LICENSING OF PLUMBERS. 

4715.3150 FEES. 

4715.3160 EXPIRATION OF LICENSES. 

4715.3170 REGISTRATION OF PLUMBER'S APPRENTICE. 

EXPLANATORY MATERIALS 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0100 PLUMBING CODE 



4715.3500 GENERAL. 

471 5.3600 TOTAL DAILY WATER REQUIREMENTS. 

4715.3700 DETERMINATION OF PEAK DEMAND. 

471 5.3800 RECOMMENDED GUIDE FOR SIZING WATER SUPPLY SYSTEM. 

4715.4100 USEFUL INFORMATION. 

WATER CONDITIONING CONTRACTORS AND INSTALLERS 

471 5.5000 SCOPE AND APPLICABILITY. 

4715.5100 DEFINITIONS. 

4715.5200 CONNECTION WITH WATER DISTRIBUTION SYSTEM. 

4715.5300 EQUIPMENT DRAIN. 

4715.5400 LOCATION. 

471 5.5500 REGENERATION SANITATION PROCEDURES. 

4715.5700 EQUIPMENT AND MATERIALS USED IN INSTALLATIONS. 

4715.5800 LICENSING. 

4715.6000 RENEWAL. 

4715.0100 DEFINITIONS. 

Subpart 1. Scope. For the purpose of this code, the following terms shall have the meaning 
indicated in this part. No attempt is made to define ordinary words which 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. 

Subp. 2. Administrative authority. "Administrative authority" means the commissioner of health. 
(When a governmental subdivision adopts and maintains a comprehensive plumbing enforcement program 
that is conducted by personnel who are Imowledgeable about plumbing installation requirements, and 
includes enforcement of all code provisions including materials, methods, inspection, and testing, the 
administrative authority shall be the governing body of the adopting unit of govermnent, its agents, and 
employees; however, the commissioner of health retains the ultimate authority to enforce Minnesota 
Statutes, sections 326.37 to 326.45, and provisions of this chapter that are necessary to ensure compliance.) 

Subp. 3. Air break (drainage system). "Air break (drainage system)" means a piping arrangement 
in which a fixture, appliance, or device is protected from backflow by discharging at or below the flood level 
rim of another fixture or receptacle whose flood level rim is lower than the bottom of the protected fixture, 
appliance, or device. 

Subp. 4. Air gap (drainage system). "Air gap (drainage system)" means the unobstructed vertical 
distance through the free atmosphere between the outlet of a waste pipe and the flood level rim of the fixture 
or receptacle into which it is discharging. 

Subp. 5. Air gap (water distribution system). "Air gap (water distribution system)" means 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 receptacle. 

Subp. 6. Anchors. See "supports." 

Subp. 7. Approved. "Approved," as applied to a material, device, or mode of construction, means 
approved by the administrative authority in accordance with the provisions of this code, or by other authority 
designated by law to give approval in the matter in question. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



PLUMBING CODE 4715.0100 



Subp. 8. Area drain. "Area drain" means a receptacle designed to collect surface or storm water 
from an open area. 

Subp. 9. Backflow. "Backflow" means the flow of water or other liquids, mixtures, or substances 
into the distributing pipes of the potable supply of water, from any source or sources other than its intended 
source. Back-siphonage is one type of backflow. 

Subp. 10. Backflow connection. "Backflow connection" means any condition whereby backflow 
can occur 

Subp. 11. Backflow preventer. "Backflow preventer" means a device or means to prevent backflow 
into the potable water system. 

Subp. 12. Backflow preventer (reduced pressure zone type). "Backflow preventer (reduced 
pressure zone type)" means an assembly of differential valves and check valves including an automatically 
opened spillage port to the atmosphere. 

Subp. 13. Back-siphonage. "Back-siphonage" means the flowing back of used, contaminated, or 
polluted water from a plumbing fixture or vessel or other sources, into a potable water supply pipe due to 
negative pressure in such pipe. 

Subp. 14. Barometric loop. "Barometric loop" means a loop of water piping rising approximately 
35 feet at its topmost point above the highest fixture it supplies. 

Subp. 15. Battery of fixtures. "Battery of fixtures" means any group of two or more similar adjacent 
fixtures which discharge into a common horizontal waste or soil branch. 

Subp. 16. Boiler blowoff. "Boiler blowofP' means an outlet on a boiler to permit emptying or 
discharge of sediment. 

Subp. 17. Boiler blowoff tank. "Boiler blowoff tank" means a vessel designed to receive the 
discharge from a boiler blowoff outlet and to cool the discharge to a temperature which permits its safe 
discharge to the drainage system. 

Subp. 18. Branch. "Branch" means any part of the piping system other than a riser, main, or stack. 

Subp. 19. Branch, fixture. See "fixture branch." 

Subp. 20. Branch, horizontal. See "horizontal branch." 

Subp. 21. Branch interval. "Branch interval" means a vertical length of stack corresponding in 
general to a story height, but in no case less than eight feet, within which the horizontal branches from one 
story or floor of the building are connected to the stack. 

Subp. 22. Branch vent. "Branch vent" means a vent connecting one or more individual vents with 
a vent stack or a stack vent. 

Subp. 23. Building classification. "Building classification" means the arrangement adopted by the 
administrative authority for the designation of buildings in classes according to occupancy. 

Subp. 24. Building drain. "Building drain" means that part of the lowest piping of the drainage 
system which receives the discharge from soil, waste, and other drainage pipes inside the walls of the 
building and conveys it to the building sewer beginning at least one foot outside the building footings. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0100 PLUMBING CODE 



Subp. 25. Building drain, sanitary. "Building drain, sanitary" means a building drain which 
conveys sewage only. 

Subp. 26. Building drain, storm. "Building drain, storm" means a building drain which conveys 
storm water but no sewage. 

Subp. 27. Building sewer. "Building sewer" means that part of the drainage system which extends 
from the end of the building drain and conveys its discharge to the public sewer, private sewer, individual 
sewage-disposal system, or other point of disposal. 

Subp. 28. Building sewer, sanitary. "Building sewer, sanitary" means a building sewer which 
conveys sewage only. 

Subp. 29. Building sewer, storm. "Building sewer, storm" means a building sewer which conveys 
storm water but no sewage. 

Subp. 30. Building subdrain. "Building subdrain" means that portion of a drainage system which 
cannot drain by gravity into the building sewer. 

Subp. 31. Circuitvent. "Circuitvenf'meansabranchventthatservestwoormoretrapsandextends 
from the downstream side of the highest fixture connection of a horizontal branch to the vent stack. 

Subp. 32. Combination fixture. "Combination fixture" means a fixture combining one sink and 
laundry tray or a two or three compartment sink and laundry tray in one unit. 

Subp. 33. Common vent. "Common vent" means a vent connecting at the junction of two fixture 
drains and serving as a vent for both fixture drains. 

Subp. 34. Conductor. "Conductor" means a pipe inside the building which conveys storm water 
from the roof to a storm drain. 

Subp. 35. Continuous vent. A "continuous vent" is a vertical vent that is a continuation of the drain 
to which it connects. 

Subp. 36. Continuous waste. "Continuous waste" means a drain from two or three compartments 
of a fixture connected to a single trap. 

Subp. 37. Cross connection. "Cross connection" means any connection or arrangement, physical or 
otherwise, between a potable water supply system and any plumbing fixture, or tank, receptacle, equipment, 
or device through which it may be possible for nonpotable, used, unclean, polluted, or contaminated water 
or other substance to enter any part of such potable water system under any condition. 

Subp. 38. Dead end. "Dead end" means a branch leading from a soil, waste, or vent pipe, building 
drain, or building sewer and terminating at a developed length of two feet or more by means of a plug, cap, 
or other fitting. 

Subp. 39. Developed length. "Developed length" means the length of pipe measured along the 
center line of the pipe and fittings. 

Subp. 40. Downspout. See "leader." 

Subp. 41. Drain. "Drain" means any pipe which carries waste water or waterbome wastes in a 
building drainage system. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



PLUMBING CODE 4715.0100 



Subp. 42. Drainage system. "Drainage system" includes all the piping which conveys sewage, rain 
water, or other liquid wastes to a legal point of disposal. It does not include the mains of a public sewer 
system, or a public sewage treatment or disposal plant. 

Subp. 43. Dwelling unit. "Dwelling unit" means one or more rooms with provision for living, 
sanitary, and sleeping facilities arranged for the use of one family or individual. 

Subp. 44. Effective opening. "Effective opening" means the minimum cross -sectional area at the 
point of water supply discharge measured or expressed in terms of diameter of a circle, or if the opening is 
not circular, the diameter of a circle of the equivalent cross sectional area. 

Subp. 45. Existing work. "Existing work" is a plumbing system or any part thereof which has been 
installed prior to the effective date of this code. 

Subp. 46. Fixture. See "plumbing fixture." 

Subp. 47. Fixture branch. A "fixture branch" is a water supply pipe between the fixture supply pipe 
and a water distributing pipe. 

Subp. 48. Fixture drain. "Fixture drain" means the drain from the trap of a fixture to the junction 
of that drain with any other drain pipe. 

Subp. 49. Fixture supply. A "fixture supply" is a water supply pipe connecting the fixture with the 
fixture branch. 

Subp. 50. Fixture unit (drainage - d.f.u.). A "drainage fixture unit" is a common measure of the 
probable discharge into the drainage system by various types of plumbing fixtures on the basis of one d.f.u. 
being equal to 7.5 gallons per minute discharge. The drainage fixture unit value for a particular fixture 
depends on its volume rate of drainage discharge, on the time duration of a single drainage operation, and 
on the average time between successive operations. 

Subp. 51. Fixture unit (supply -s.f.u.). A "supply fixture unit" is a common measure of the probable 
hydraulic demand on the water supply by various types of plumbing fixtures. The supply fixture unit value 
for a particular fixture depends on its volume rate of supply operation, and on the average time between 
successive operations. 

Subp. 52. Flood level rim. "Flood level rim" means the top edge of the receptacle from which water 
overflows. 

Subp. 53. Flow pressure. "Flow pressure" the pressure in the water supply pipe near the faucet or 
water outlet while the faucet or water outlet is wide open and flowing. 

Subp. 54. Flushometer valve. "Flushometer valve" means a device which discharges a 
predetermined quantity of water to fixtures for flushing purposes and is actuated by direct water pressure. 

Subp. 55. Flushvalve. "Flush valve" means a device located at the bottom ofa flush tank for flushing 
water closets and similar fixtures. 

Subp. 56. Grade. "Grade" means the fall (slope) of a line of pipe in reference to a horizontal plane. 
In drainage it is usually expressed as the fall in a fraction of an inch per foot length of pipe. 

Subp. 57. Grease interceptor. See "interceptor." 

Subp. 58. Hangers. See "supports." 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0100 PLUMBING CODE 10 



Subp. 59. Horizontal branch drain. "Horizontal branch drain" means a drain pipe extending 
horizontally from a soil or waste stack or building drain with or without vertical sections or branches, 
which receives the discharge from one or more fixture drains on the same floor as the horizontal branch and 
conducts it to the soil or waste stacli or to the building drain. 

Subp. 60. Horizontal pipe. "Horizontal pipe" means any pipe or fitting which makes an angle of 
less than 45 degrees with the horizontal. 

Subp. 61. Individual sewage disposal system. "Individual sewage disposal system" means a system 
for disposal of domestic sewage by means of a septic tank, cesspool, or mechanical treatment, designed for 
use apart from a public sewer to serve a single establishment or building. 

Subp. 62. Indirect waste pipe. "Indirect waste pipe" means a waste pipe that does not connect 
directly with the drainage system but conveys liquid wastes by discharging into a plumbing fixture, 
interceptor, or receptacle which is directly connected to the drainage system. 

Subp. 63. Individual vent. "Individual vent" means a pipe installed to vent a fixture trap and which 
connects with the vent system above the fixture served or terminates in the open air 

Subp. 64. Industrial wastes. "Industrial wastes" means liquid or waterbome waste from industrial 
or commercial processes except domestic sewage. 

Subp. 65. Insanitary. "Insanitary" means a condition which is contrary to sanitary principles or 
injurious to health. 

Subp. 66. Interceptor. "Interceptor" means 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. 

Subp. 67. Leader. "Leader" means the water conductor from the roof to the building storm drain or 
other means of disposal. 

Subp. 68. Liquid waste. "Liquid waste" means the discharge from any fixture, appliance, or 
appurtenance which does not receive fecal matter. 

Subp. 69. Load factor. "Load factor" means the percentage of the total connected fixture unit flow 
which is likely to occur at any point in the plumbing system. 

Subp. 70. Loop vent. "Loop vent" means a circuit vent which loops back to connect with a stack 
vent instead of a vent stack. 

Subp. 71. Main. "Main" means the principle pipe artery to which branches may be connected. 

Subp. 72. Main vent. "Main vent" means the principle artery of the venting system to which vent 
branches may be connected. 

Subp. 73. May. The word "may" is a permissive or allowable term for alternative procedures. 

Subp. 73a. Must. The word "must" is a mandatory term. 

Subp. 74. Nonpotable water. Water not safe for drinking because it may contain impurities in 
amounts sufficient to cause disease or harmful physiological effects, or water that does not conform to the 
public water supply quality requirements of parts 4720.0100 to 4720.2500 or the regulations of the local 
public health authority having jurisdiction. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



11 PLUMBING CODE 4715.0100 



Subp. 75. Offset. "Offset" means a combination of elbows or bends which brings one section of the 
pipe out of line but into a line parallel with the other section. 

Subp. 76. Plumbing. "Plumbing" means the business, trade, or work having to do with the 
installation, removal, alteration, or repair of plumbing and drainage systems or parts thereof. 

Subp. 77. Plumbing appliance. "Plumbing appliance" means any one of a special class of 
plumbing fixture which is intended to perform a special 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. 

Subp. 78. Plumbing appurtenance. "Plumbing appurtenance" means a manufactured device, or a 
prefabricated assembly, or an on-the-job assembly of component parts, and which 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 the drainage system. It is presumed that it performs some useful function 
in the operation, maintenance, servicing, economy, or safety of the plumbing system. 

Subp. 79. Plumbing inspector official. See "administrative authority." 

Subp. 80. Plumbing fixture. "Plumbing fixture" means a receptacle or device which is either 
permanently or temporarily connected to the water distribution system, and demands a supply of water 
therefrom, or it discharges used water, liquid-borne waste materials, or sewage either directly or indirectly 
to the drainage system, or which requires both a water supply connection and a discharge to the drainage 
system. Plumbing appliances as a special class of fixture are further defined. 

Subp. 81. Plumbing system. The "plumbing system" means and includes all potable water supplies 
and distribution pipes, all plumbing fixtures and traps, all drainage and vent pipes and all building drains, 
including their respective joints and connections, devices and appurtenances within the property lines of the 
premises and shall include potable water treatment or using equipment. 

Subp. 82. Potable water. Water free from impurities present in amounts sufficient to cause disease or 
harmful physiological effects and conforming in its bacteriological and chemical quality to parts 4720.0100 
to 4720.2500 or the regulations of the local public health authority having jurisdiction. 

Subp. 83. Private or private use. In the classification of plumbing fixtures, "private" applies to 
fixtures in residences and apartments, and to fixtures in private bathrooms of hotels, as well as similar 
installations in other buildings where fixtures are intended for use of one family or an individual. 

Subp. 84. Public or public use. In the classification of plumbing fixtures, "public" applies to fixtures 
in general toilet rooms of schools, gymnasiums, hotels, railroad stations, bars, public comfort stations, and 
other installations (whether pay or free) where fixtures are installed so that their use is similarly unrestricted. 

Subp. 84a. Readily accessible. "Readily accessible" means capable of being reached safely and 
quickly for operation, repair, or inspection without requiring those to whom ready access is requisite to 
remove obstacles, panels, or similar obstructions. 

Subp. 85. Receptor. "Receptor" means an approved plumbing fixture or device of such material, 
shape, and capacity as to adequately receive the discharge from indirect waste pipes, so constructed and 
located as to be readily cleaned. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0100 PLUMBING CODE 12 



Subp. 86. Relief vent. "Relief vent" means a vent, the primary function of which is to provide 
additional circulation of air between drainage and vent systems or to act as an auxiliary vent on a specially 
designed system. 

Subp. 87. Return offset. "Return offset" means a double offset installed so as to return the pipe to 
its original alignment. 

Subp. 88. Re vent pipe. See "individual vent." 

Subp. 89. Rim. "Rim" means an unobstructed open edge of a fixture. 

Subp. 90. Riser. "Riser" means a water supply pipe which extends vertically one full story or more 
to convey water to branches or to a group of fixtures. 

Subp. 91. Roof drain. "Roof drain" meansadraininstalledtoreceivewatercoUectingonthesurface 
of a roof and to discharge it into a leader or conductor. 

Subp. 92. Roughing in. "Roughing in" means the installation of all parts of the plumbing system 
which can be completed prior to the installation of fixtures. This includes drainage, water supply, and vent 
piping, and necessary fixture supports. 

Subp. 93. Sand interceptor or trap. See "interceptor." 

Subp. 94. Sanitary sewer. "Sanitary sewer" means a sewer which carries sewage and excludes 
storm, surface, and ground water. 

Subp. 95. Sewage. "Sewage" means any liquid waste containing animal or vegetable matter in 
suspension or solution and may include liquids containing chemicals in solution. 

Subp. 96. Sewage ejector. "Sewage ejector" means a device for moving sewage by entraining it in 
a high velocity jet of steam, air, or water. 

Subp. 97. Sewer. "Sewer" means an artificial conduit, usually underground, for carrying off waste 
water and refuse. 

Subp. 98. Slope. See "grade." 

Subp. 99. Shall. The word "shall" is a mandatory term. 

Subp. 100. Should. The word "should" is a nonmandatory term, but describes recommended 
procedures. 

Subp. 101. Soil pipe. "Soil pipe" means a pipe which conveys the discharge of water closets or 
similar fixtures containing fecal matter with or without the discharge of other fixtures to the building drain 
or building sewer. 

Subp. 102. Special wastes. "Special wastes" means wastes which require special treatment before 
entry into the normal plumbing system. 

Subp. 103. Special waste pipe. "Special waste pipe" means pipe which conveys special wastes. 

Subp. 104. Stack. "Stack" is a general term for any vertical line of soil, waste, or vent piping 
extending through one or more stories. Excepting vertical vent branches which do not extend through the 
roof and which pass through less than two stories, before being reconnected to a vent stack or stack vent. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



13 PLUMBING CODE 4715.0100 



Subp. 105. Stack group. "Stack group" means a group of fixtures located adjacent to the stack so 
that by means of proper fittings, vents may be reduced to a minimum. 

Subp. 106. Stack vent. "Stack vent" means the extension of a soil or waste stack above the highest 
horizontal drain connected to the stack. 

Subp. 107. Storm drain. See "building drain, storm." 

Subp. 108. Storm sewer. "Stormsewer"meansasewerusedforconveyinggroundwater, rainwater, 
surface water, or similar nonpoUutional wastes. 

Subp. 109. Sump. "Sump"meansawatertighttankwhichreceivessewageorliquidwasteandwhich 
is located below the normal grade of the gravity system and must be emptied by mechanical means. 

Subp. 110. Sump pump. "Sump pump" means a mechanical device other than an ejector for 
removing sewage or liquid waste from a sump. 

Subp. 111. Supports. "Supports" means devices for supporting and securing pipe, fixtures, and 
equipment. 

Subp. 112. Trap. "Trap" means a fitting or device which provides, when properly vented, a liquid 
seal to prevent the emission of sewer gases without materially affecting the flow of sewage or waste water 
through it. 

Subp. 113. Trap seal. "Trap seal" means the vertical distance between the crown wire and the top 
dip of the trap. 

Subp. 114. Vacuum. "Vacuum" means any pressure less than that exerted by the atmosphere. 

Subp. 115. Vacuum breaker, nonpressure type (atmospheric). "Nonpressure type vacuum 
breaker" means a vacuum breaker which is not designed to be subjected to static line pressure. 

Subp. 116. Vacuum breaker, pressure type. "Vacuum breaker pressure type" means a vacuum 
breaker designed to operate under conditions of static line pressure. 

Subp. 117. Vent pipe. "Vent pipe" means any pipe provided to ventilate a building drainage system 
and to prevent trap siphonage and back pressure. 

Subp. 118. Ventstack. "Vent stack" means a vertical vent pipe installed to provide circulation of air 
to and from the drainage system. 

Subp. 119. Vent system. "Vent system" means 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. 

Subp. 120. Vertical pipe. "Vertical pipe" means any pipe or fitting which makes an angle of 45 
degrees or less with the vertical. 

Subp. 121. Waste. See "liquid waste" and "industrial waste." 

Subp. 122. Waste pipe. "Waste pipe" means a pipe which conveys only liquid waste free from fecal 
material. 

Subp. 123. Water distributing pipe. "Water distributing pipe" means a pipe conveys water from 
the water service pipe to the point of usage. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0200 PLUMBING CODE 14 



Subp. 124. Water outlet. "Water outlet" means a discharge opening through which water is supplied 
to a fixture, into the atmosphere {except into an open tank which is part of the water supply system), to a 
boiler or heating system, or to any devices or equipment requiring water to operate. 

Subp. 125. Water service pipe. "Water service pipe" means the pipe from the water main or other 
source of water supply to the water distributing system of the building served. 

Subp. 126. Water supply system. "Water supply system" means the water service pipe, the water 
distributing pipes, and the necessary connecting pipes, fittings, control valves, and all appurtenances within 
the building or outside the building within the property lines. 

Subp. 127. Wet vent. "Wet vent" means a vent which also serves as a drain. 

Subp. 128. Yoke vent. A "yoke vent" is a pipe connecting upward from a soil or waste stack to a 
vent stack for the purpose of preventing pressure changes in the stacks. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 9 SR 1557; L 1977 c 305 s 39; 11 SR 1405; 15 SR 76; 23 SR 686 

Posted: June 11, 2008 

4715.0200 BASIC PLUMBING PRINCIPLES. 

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

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

back-siphonage. 

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

C. 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 habitation shall be equipped with sufficient sanitary facilities. 

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

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



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



15 PLUMBING CODE 4715.0200 



F. The drainage system shall be designed, constructed, and maintained to conduct the waste 
water with velocities which will prevent fouling, deposition of solids, and clogging. 

G. The drainage system shall be provided with an adequate number of cleanouts so arranged 
that in case of stoppage the pipes may be readily cleaned. 

H. Where a building drainage system may be subjected to back flow of sewage, suitable 
provision shall be made to prevent its overflow in the building. 

I. 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. 

J. 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 drainage system. 

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

L. The plumbing system shall be subjected to adequate tests and to inspections in a manner 
that will disclose all leaks and defects in the work or the material. 

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

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

O. Plumbing fixtures shall be made of durable, smooth, nonabsorbent, and corrosion-resistant 
material and shall be free from concealed fouling surfaces. 

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

Q. Plumbing fixtures shall be designed and adjusted to use the minimum quantity of water 
consistent with proper performance and cleaning. Hot water shall be supplied to all plumbing fixtures which 
normally need or require hot water for their proper use and function. 

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

S. Each fixture shall be provided with a separate, accessible, self-scouring, reliable water-seal 
trap placed as near to the fixture as possible. 

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

U. If water closets or other plumbing fixtures are installed in a building where there is no 
sewer within a reasonable distance, suitable provision must be made for treatment of the building sewage by 
methods which meet the design criteria of the Minnesota Pollution Control Agency as prescribed in chapter 
7080. One-family and two-family dwellings must comply with applicable local ordinances. 

V. Devices for heating water and storing it shall be designed and installed to prevent all dangers 
from explosion and overheating. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0300 PLUMBING CODE 16 

W. Sewage or other waste shall not be discharged into surface or subsurface water unless it 
first has been subjected to an acceptable form of treatment. 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 9 SR 1557; 15 SR 76; 17 SR 1279 

Posted: July 31, 2007 

4715.0210 [Renumbered 4715.0200] 
Posted: July 31, 2007 

4715.0220 [Renumbered 4715.0200] 

Posted: July 31, 2007 

4715.0230 [Renumbered 4715.0200] 

Posted: July 31, 2007 

4715.0240 [Renumbered 4715.0200] 
Posted: July 31, 2007 

4715.0250 [Renumbered 4715.0200] 
Posted: July 31, 2007 

4715.0260 [Renumbered 4715.0200] 

Posted: July 31, 2007 

4715.0270 [Renumbered 4715.0200] 
Posted: July 31, 2007 

4715.0300 GENERAL REGULATIONS OF PLUMBING CONSTRUCTION. 

Subpart 1. Grades of horizontal piping. See parts 4715.2400 and 4715.2310, subpart 2. 

Subp. 2. Changes of direction. See part 4715.2410. 

Subp. 3. Prohibited fittings. See part 4715.2420. 

Subp. 4. Protection of material. All pipes passing under or through walls shall be protected from 
breakage. All pipes passing through or in contact with cinder, concrete, or other corrosive material shall 
be protected against external corrosion by protective coating, wrapping, or other means that will resist such 
corrosion. 

Subp. 5. Construction. Construction shall be of such character as to secure fully the results sought 
to be obtained in all sections of the code. 

Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



17 PLUMBING CODE 4715.0320 



Subp. 6. Exclusion of materials detrimental to drainage system. See parts 4715.1600 and 
4715.1610. 

Statutory Authority: MS s 326.37 to 326.45 

History: 17 SR 1279 

Posted: July 31, 2007 

4715.0310 USE OF PUBLIC SEWER AND WATER SYSTEMS REQUIRED. 

If a public sewer is accessible in a street or alley to a building or premises and the connection is feasible, 
liquid wastes from any plumbing system in that building must be discharged into the public sewer unless 
otherwise prohibited by this code or a local ordinance. 

If a public water supply system is accessible, the water distribution system must be connected to 
it unless otherwise permitted by the administrative authority. A water well taken out of service because 
a person is connecting to a public water supply must either be maintained for a use such as irrigation, or 
sealed and abandoned in accordance with the Minnesota Water Well Construction Code. (Minnesota Rules, 
chapter 4725) 

If either a public sewer or water supply system or both are not available, an individual water supply 
or sewage disposal system, or both, conforming to the published standards of the administrative authority 
must be provided. 

Every building must have its own independent connection with a public or private sewer, except that 
a group of buildings may be connected to one or more manholes which are constructed on the premises, 
and connected to a public or private sewer. These manholes must conform to the standards set by the local 
sewer authority. 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 9 SR 1557; 15 SR 76 

Posted: July 31, 2007 

4715.0320 CONFORMANCE WITH CODE. 

Subpart 1. Scope. As provided in Minnesota Statutes, section 326.37, the Minnesota Plumbing Code 
applies to all new plumbing installations, including additions, extensions, alterations, and replacements 
connected to a water or sewage disposal system owned or operated by or for a municipality, institution, 
factory, office building, hotel, apartment building, or other place of business regardless of location or the 
population of the city or town in which it is located. 

Subp. 2. New buildings. All plumbing materials and plumbing systems or parts thereof must be 
installed to meet the minimum provisions of this code. 

Subp. 3. Existing buildings. In existing buildings or premises in which plumbing installations are 
to be altered, renovated, or replaced, the new materials and work must meet the provisions of this code. If 
the administrative authority finds that the full performance of bringing the work into compliance with all 
requirements of this code would result in exceptional or undue hardship by reason of excessive structural or 
mechanical difficulty, or impracticability, a deviation may be granted by the administrative authority only 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0340 PLUMBING CODE 18 

to the extent the deviation can be granted without endangering the health and safety of the occupants and 
the pubhc. 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 15 SR 76 

Posted: July 31, 2007 

4715.0330 ALTERNATE FIXTURES, APPURTENANCES, MATERIALS, AND METHODS. 

Subpart 1. Approval of alternate fixtures. The administrative authority may approve the use of 
fixtures, appurtenances, materials, and methods of a type not expressly approved, nor expressly prohibited 
by, this code after determination that such fixtures, appurtenances, material, or method is of such design or 
quality, or both, as to appear to be suitable, safe, and sanitary for the use for which it is intended. 

Subp. 2. Proofof suitability of fixture. Any person desiring to install or use a fixture, appurtenance, 
material, or method of a type not expressly authorized nor expressly prohibited by this code shall, prior to 
such installation or use, submit to the administrative authority such proof as may be required to determine 
whether such fixture, appurtenance, material, or method is of such design or quality, or both, as to appear to 
be suitable, safe, and sanitary for the use for which it is intended. If the administrative authority determines 
that it does appear to be suitable, safe, and sanitary for the use which it is intended, it may permit such use. 

Subp. 3. Tests. When there is insufficient evidence to verify claims for alternate materials, the 
administrative authority may require as proof of suitability a test by a testing laboratory approved by the 
administrative authority, at the expense of the applicant, demonstrating that the performance characteristics 
of the alternate materials are substantially equal to or exceed those of authorized materials. 

Tests shall be made in accordance with generally recognized standards; but in the absence of such 
standards, the administrative authority shall specify tiie test procedure. 

The administrative authority 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. 

Subp. 4. Advisory council. The administrative authority may appoint an advisory council to study 
and make recommendations concerning the uses of new fixtures, appurtenances, materials, and methods. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0340 HEALTH AND SAFETY. 

Subpart 1. Installation of additional plumbing. Where a health or safety hazard exists by reason 
of an existing plumbing installation or lack thereof, the owner or the owner's agent shall be responsible for 
installing additional plumbing or making such corrections as may be necessary to abate such nuisance and 
bring the plumbing installation within the provisions of this code. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



19 PLUMBING CODE 4715.0420 



Subp. 2. Condemned equipment. Any plumbing equipment condemned by the administrative 
authority because of wear, damage, defects, or sanitary hazards shall not be reused for plumbing purposes. 

Subp. 3. Used material or equipment. It shall be unlawful to install any used plumbing material or 
equipment unless it conforms to the standards and rules set forth in this code. 

Subp. 4. Freezing. Water service piping shall be installed below normal frost penetration for 
below-grade piping unless special provisions are made to prevent freezing. Plumbing piping in exterior 
building walls shall be adequately protected against freezing by insulation or heat or both. 

Statutory Authority: MS s 326.37 to 326.45 

History: 17 SR 1279 

Posted: July 31, 2007 

MATERIALS 

4715.0400 QUALITY OF MATERIALS. 

All materials used in any drainage or plumbing system or part thereof shall be free from defects, and 
no materials which are damaged or defective shall knowingly be installed. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0410 IDENTIFICATION OF MATERIALS. 

All materials must be marked, unless otherwise easily identifiable, so as to provide a visual means of 
identification as to types, grades, weights, and strengths. The installer shall, as far as possible, position the 
identification marks so as to provide ease of inspection by the administrative authority. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0420 STANDARDS FOR PLUMBING MATERIALS. 

Subpart 1. Approved materials. A material shall be considered approved if it meets one or more of 
the standards cited in subpart 3. Materials not listed in subpart 3 shall be used only as provided for in part 
4715.0330, or as permitted elsewhere in this code. 

Subp. 2. Abbreviations. Abbreviations in subpart 3 refer to the following: 

A. ANSI, American National Standards Institute, 10 East 40th Street, New York, New York 
10016; 

B. ASTM, American Society for Testing and Materials, 100 Barr Harbor Drive, West 
Conshohocken, PA 19428-2959; 

C. AWWA, American Water Works Association, 2 Park Avenue, New York City, New York 
10016; 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0420 PLUMBING CODE 



20 



D. CSA, Canadian Standards Association, 178 Rexdale Boulevard, Rexdale (Toronto), 
Ontario, Canada M9W 1R3; 

E. CS, Commercial Standards available from: Commodity Standards Division, Office of 
Industry and Commerce, U. S. Department of Commerce, Washington, D. C. 20234; 

F. FS, Federal Specifications available from: Federal Supply Service, Standards Division, 
General Services Administration, Washington, D. C. 20406; 

G. NSF, NSF International, Ann Arbor, Michigan 48106; 

H. FHA, Federal Housing Authority, Architectural Standards Division, Washington, D. C; 

I. AASHTO, American Association of State and Highway Transportation Officials, 444 North 
Capital Street Northwest, Suite 249, Washington, D. C. 20001. 

Subp. 3. Standards for plumbing materials. 



DESCRIPTION 



ANSI 



ASTM 



FS 



OTHER 



I. 



CAST IRON PIPE AND FITTINGS 

A21.2 
A21.6 A-74 



WW-P-401C 



CS188 



lA 



IB 



IC 



Cast Iron Pipe and 




Fittings Extra Heavy 


A21.8 


Cast Iron Pipe 




Centrifugally Cast 




Only and Fittings 


A21.6 


Service Weight 


A21.8 


Cast Iron Mechanical 


A21.il 


(Gland Type) Pipe 


A21.2 




A21.6 



A-74 



WW-P-401C 



CS188 



WW-P-421a 



ID 



Cast Iron Mechanical A21.8 



(Gland Type) Pipe 


A21.4 


Cement Lined 


A21.2 




A21.6 




A21.8 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



21 



PLUMBING CODE 4715.0420 



IE Cast Iron Short Body A21.10 

Water Service Fittings 

(2"-12") 



AWWA ClOO 



IF 



Cast Iron Threaded Pipe A40.5 



IG High Silicon Pipe, 

Fittings Cast Iron 



IH Cast Iron Threaded 

Fittings Black and 
Galvanized 125# B16.4 



WW-P-501 



IJ Cast Iron Drainage 

Fittings Black and 
Galvanized 



B16.12 



WW-P-491 



IK Hubless Cast Iron Pipe 

and Fittings 



CISPI Standard 
301-69T 
CS A/CAN 
3-B70 



IL Ductile Iron Pipe 

Flanged 



A21.15 



AWWAC115 



IM Ductile Iron Pipe 

Rubber Gasket Joints 



A21.51 



AWWAC151 



n. 



STEEL AND WROUGHT IRON PIPE FITTINGS 



2A Steel Pipe, Welded and 

Seamless Galvanized, 
Schedule 40 and Above B36. 1 

B36.20 



A53 



WW-P-406 
6(1) 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0420 PLUMBING CODE 



22 



2B Wrought Iron Pipe, 

Galvanized Schedule 
40 and Above B36.2 

2C(a) Stainless Steel Pipe B36.19 

2C(b) Stainless Steel Pipe A112.3.1 



2D Galvanized Malleable 

Fittings 150 psi and 
Above B16.3 



A197 



2E 



Steel Unions, 
Galvanized 



WW-V-531 C 



2F Corrugated Steel Pipe, 

Aluminized and fittings 

(18- to 120-inch) 
(Storm only) 



A760 
A796 



AASHTO M36 



ni. 



COPPER AND COPPER BASE PIPE AND FITTINGS 



3 A Red Brass Pipe, Regular 

and Heavier H27.1 



B42B 



3B 



Seamless Brass Tube H36.1 



3C Brass or Bronze 

Threaded Fittings 125 

lbs. and Over B16.15 



B62 



WW-P-460 



3D Brass or Bronze Flare 

Fittings 125 lbs. and 
Over, Heavy Duty Long 
Collar Type 



B62 



3E Seamless Copper Tube 

Type K, Soft Temper H23.1 



B88 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



23 



PLUMBING CODE 4715.0420 



3F Seamless Copper Tube 

Type K, Hard Temper H23.1 B88 

3G Seamless Copper Tube 

Type L, Soft Temper H23.1 B88 

3H Seamless Copper Tube 

Type L, Hard Temper H23.1 B88 



3H(a) Welded Copper Alloy 

194 Water, Tube, Type 
"Heavy," Hard Temper 



B543-72 



OFT194-101A 

Navfac 
TS-15400 



3H(b) Stainless Steel Water 

Tubing, Type SL, 
Copper Plated Coating 
(HWT-T439) 



A-651 



3J Seamless Copper Tube, 

Type M, Hard and Soft 
Temper H23.1 



B88 



3J(a) Welded Copper Alloy 

194 Water 

Tube, Type "Standard," 
Hard Temper 



B543-72 



OFT194-101A 

Navfac 
TS-15400 



3J(b) Stainless Steel Water A-268 

Tubing, Type SM, 
Copper Plated Coating 
(HWT-T439) 



A-651 



3K Seamless Copper Tube 

Type DWV H23.3 



B306 



3L 



Copper Pipe LPS. 



H26.1 



B42 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0420 PLUMBING CODE 



24 



3M Copper Pipe, 

Threadless Type T 
P and Fittings 



H26.2 B302 



3N Cast Bronze and B16.22 

Wrought Solder Joint H23.1 
Pressure Fitting B16.18 



30 Cast Bronze and 

Wrought Solder Joint D 

WV Fittings B16.23 



3P 



3Q 



Copper Alloy Water 




Tube 1/2 Inch and 3/4 


B447 


Inch 


B75 


Welded Brass Water 


B587 


Tube 1/2 Inch and 3/4 




Inch 





IV. 



LEAD PIPE AND FITTINGS 



4A Lead Pipe AA 



WW-P-325-44 



4B Lead Pipe AAA 



WW-P-325-44 



4C Lead Bends and Traps 



WW-P-325-44 



4D 



Sheet Lead 



QQ-L201d 



V. 



SILICA AND EARTH PRODUCTS PIPE AND FITTINGS, NONMETALLIC 



5 A Asbestos-Cement 

Pressure Pipe and Fitting 



C500 
C296 



SS-P351 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



25 



PLUMBING CODE 4715.0420 



5B Asbestos-Cement Water Pipe and 

Fittings C500 



SS-P-351 



AWWA C400 



5C Asbestos-Cement Nonpressure Pipe 

and Fittings C428 



XX-P-331 



5D Asbestos-Cement Perforated 

Underdrain Pipe and Fittings 



C508 



5E Vitrified Clay Pipe, Standard C13 

Strength and Stronger Fittings C200 

5F Unglazed Clay Pipe, Extra Strengtli 

and Fittings C278 

5G Perforated Clay Pipe and Fittings C211 

5H Borosilicate Glass Pipe and Fittings 

60 psi 



5J 



Nonreinforced Concrete Drain Tile 



C412 



AASHTO 
M178 



5K Nonreinforced Concrete Pipe 



C14 



SS-P-371 



AASHTO 

M86 

CSA-A257.1 



5L Perforated Concrete Pipe, 

Underdrainage 



C444 



5M Reinforced Concrete Pipe 



C76 



SS-P-375 



CSA-A257.2 



5N Reinforced and Prestressed Concrete 

Pipe, Pressure Type and Fittings 



50 Bituminized Fiber Drain and Sewer 

Pipe D1860 



SS-P-1540A 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0420 PLUMBING CODE 



26 



5P Perforated Bituminized Fiber Pipe 

for General Drainage 



D2311 



SS-P-1540A 



VI. PLASTIC PIPE AND FITTINGS DRAIN, WASTE AND VENT 



6A Acrylonitrile -Butadiene- Styrene D2661 

(ABS) 

Type 1, Schedule 40 Cellular core F628 



L-P-322a 
FHA-MPS 



NSF14 

CSA-B181.1 

CS270 



6B (1) Polyvinyl Chloride (PVC) 

Schedule 40 Unthreaded 
Schedule 80 can be threaded 
Cellular core 



D2665 



F891 



L-P-320a 
FHA-MPS 



NSF14 
CS272 
CSA-B181.2 



Fabricated Fittings (8- to 24-inch) D33 1 1 

Fabricated Fittings (8-inch and larger F1866 
with mitered joints 4-inch and larger) 



6B (2) Polyvinyl Chloride (PVC) 

Schedule 30 (3-inch only) 



D2949 



L-P-001221 



6B (3) Polyvinyl Chloride (PVC) 

Schedule 40 (14- to 24-inch only) 
with ASTM D3311 fittings 



D1785 



Fabricated Fittings (8-inch and larger F1866 
with mitered joints 4-inch and larger) 

6B (4) Polyvinyl Chloride (PVC) 

Schedule 40 and 80 SDR 21 and 

SDR 26 (6-inch and larger) D2241 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



27 



PLUMBING CODE 4715.0420 



6B (5) Corrugated Poly-vinyl Chloride 

(PVC) Schedule 40 (4- to 36-inch) 
with ASTM D3212 fittings (Storm 
only) F949 

BUILDING SEWER 



6C 



(1) Styrene - Rubber 



D2852 



CS228 



6C (2) Polyvinyl Chloride (PVC) 

(18- to 27-inch only) 
(18-inch and larger) 



D3034 
F789 

F679 

F794 



WW-P-00380a 



CSA-B182.2 



6C (3) Acrylonitrile- 

Butadiene- Styrene (ABS) 



D2751 



CSA-B182.1 



6C (4) Corrugated High Density AASHTO M294 

Polyethylene (Corrugated HDPE) AASHTO MP7 

(12- to 60-inch) with ASTM D3212 
fittings (Storm only) 

WATER SERVICE - Minimum working pressure rating shall be at least 150 psi for municipal water 
service and 100 psi for other service. 



6D 



6E 



Polyethylene (PE) 



Acrylonitrile- 
Butadiene- Styrene 
(ABS) 



B72.1 



B72.3 



D2239 


LP-315a 


NSF14 


D2737 


FIIA-UM-31C 


CS255 
CSA-B137.1 


D2282 




NSF14 
CS254 



6F 



6G 



Polyvinyl Chloride 
(PVC) 



Polybutylene 



B72.2 



D2241 


L-P-1036 


NSF14 


D1785 


FHAUM-41 


CS256 
CSA-B137.3 


D2662 




NSF14 


D2666 




CSA-B137.7 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0420 PLUMBING CODE 



28 



WATER DISTRIBUTION - Polybutylene (PB) systems (PB tubing together with recommended 
fittings) and chlorinated polyvinyl chloride (CPVC) pipe together with fittings must be tested by the 
manufacturer at 150 psi and 210 degrees Fahrenheit for a period of not less than 48 hours by a qualified 
independent testing laboratory acceptable to the administrative authority. Cross-linked polyethylene (PEX) 
tubing systems together with approved fittings must be tested at 150 psi and 210 degrees Fahrenheit 
for a period of not less than 30 days by a qualified independent testing laboratory acceptable to the 
administrative authority. 



6K 



Polybutylene 



D3309 



CSA-B137.8 
(tubing) 



6L Chlorinated polyvinyl 119.1, 

chloride (CPVC) 119.2 



D2846 



NSF14 
FHA Bulletin 

#76 
CSA-B137.6 



6M Cross -linked 

Polyethylene (PEX) 
Systems 



F876 
F877 



NSF 14 
NSF61 



6N Metal Insert Fittings 

Utilizing a Copper 
Crimp Ring for PEX 
Tubing 



F1807 



NSF 14 
NSF 61 



60 Cold Expansion Fittings 

with PEX Reinforcing 
Rings for Use with PEX 
Tubing 



F1960 



NSF 14 

NSF 61 



6S 



SPECIAL WASTES 
Polyethylene 



D2239 



LP 315a 



PS 10-69 
PS 11 -69 
PS12-69 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



29 



PLUMBING CODE 4715.0500 



6T 



Polypropylene 



F1412 



6U Polyvinylidene 

Fluoride (PVDF) 



F1673 



GENERAL DRAINAGE 



6W 



Polyethylene 
(corrugated) 



F405 



Vn. FIBERGLASS PIPE AND FITTINGS 

7A Fiberglass pipe (reinforced D2996 NSF14 

thermosetting resin pipe) (one- NSF61 

to 16-inch) (18- to 48-inch must be AWWA C-950 

manufactured in accordance with 
ASTM D2996) 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 9 SR 1557; 11 SR 1405; 15 SR 76; 19 SR 590; 23 SR 686; 28 SR 146 

Posted: July 31, 2007 

PIPING SYSTEM MATERIALS 

4715.0500 WATER SUPPLY SYSTEMS. 

When selecting the material and size for water service pipe, tubing, 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. 

Pipe and fitting materials for water service and distribution must be of a type specifically permitted 
by parts 4715.0510 and 4715.0520, and must be verified to contain no more than eight percent lead. 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 15 SR 76 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0520 PLUMBING CODE 30 

4715.0510 WATER SERVICE PIPE. 

The following materials may be used for water service pipe: 

A. Cast iron pipe IC and ID both with IE fittings with the provisions that bends, tees, and plugs 
shall be anchored by rods. Poured in place concrete thrust blocks or anchor rods shall be used behind all 

changes of direction of 45 degrees or greater so as to maintain a water tight joint. 

B. Steel pipe 2A, wrought iron pipe 2B, both with 2D and 2E fittings, with the provision that 
all exposed threads must be coal tar enamel coated and wrapped. 

C. Red brass pipe 3A, and copper 3L, with 3C fittings, with the provision that every joint is 
supported by durable nonmetallic support and pipe to be laid on a continuous granular bed. 

D. Copper tube 3E or 3G and 3D or 3N fittings. 

E. Asbestos cement pipe 5A and fittings with the provision that this material be supported 
continuously and laid in granular soil and only in yard areas. Further that it not be used to convey extremely 
soft water, and shall pass through the floor within three feet of the outside wall. 

F. Concrete pipe 5N. 

G. Plastic pipe 6D, 6E, 6F, and 6G may be used for water service pipe only up to the water meter 
or pressure tank and provided there is no more than two feet of such piping exposed within the building. 
These materials shall be installed in accordance with ASTM D 2774-72. Particular care shall be taken to 
avoid sharp edges in contact with the pipe and to provide for expansion and contraction. 

H. Ductile iron pipe IL and IM. 

L Fiberglass pipe 7A. Installation must be in accordance with the manufacturer's requirements, 
recommendations, and guidelines. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 9 SR 1557; 11 SR 1405; 19 SR 590; 23 SR 686 

Posted: July 31, 2007 

4715.0520 WATER DISTRIBUTION PIPE. 

The following materials may be used for water distribution pipe: 

A. Cast iron with IC and ID fittings. 

B. Steel pipe 2A and wrought iron 2B with 2D and 2E fittings with the provision that this 
material may not be laid underground nor embedded in masonry construction unless all threads are coal tar 
enamel coated and wrapped. 

C. Steel pipe 2C(a), stainless. 

D. Brass 3A pipe or tube 3B with 3C fittings. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



31 PLUMBING CODE 4715.0530 



E. Copper tube 3E or 3G with 3N wrought fittings or 3D fittings with provisions that it be 
installed to allow for expansion or contraction and that all stubs through concrete floors must be sleeved or 
protected by resilient material. 

F. Copper tube 3H, 194 water tube 3H(a), or stainless water tubing 3H(b) with 3N fittings 
except that this material may not be buried under or embedded in a concrete slab. 

G. Copper 3J, 194 water tube 3J{a), stainless steel water tubing 3J(b), copper alloy 3P, or 
welded brass 3Q with 3N fittings may be installed exposed or in frame partitions, or in tunnels and shafts, 
except that this material may not be laid underground or embedded in masonry or concrete. 

H. Copper 3L and 3C fittings. 

I. Copper 3M with fittings. 

J. Plastic tubing 6K with fittings. Installation must be in accordance with International 
Association of Plumbing and Mechanical Officials (lAPMO) Installation Standard 22-84. 

K. Plastic pipe 6L and corresponding fittings. Installation must be in accordance with 
International Association of Plumbing and Mechanical Officials (lAPMO) Installation Standards 20-98; 
however, this material may be air tested. 

L. Cross-linked polyethylene (PEX) tubing 6M with fittings 6N or 60 shall be certified by 
an independent third-party certifier. The water distribution system shall be installed by a factory-trained 
installer in accordance with the manufacturer's installation instructions. Tubing and fittings must be marked 
with the appropriate ASTM designations by the manufacturer. 

M. Fiberglass pipe 7A. Installation must be in accordance with the manufacturer's 
requirements, recommendations, and guidelines. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 9 SR 1557; 11 SR 1405; 15 SR 76; 23 SR 686; 28 SR 146 

Posted: July 31, 2007 

4715.0530 BUILDING SEWERS. 

The following materials may be used for building sewers: 

A. Cast Iron lA and IB and fittings and Hubless Cast Iron IK. 

B. Cast Iron IC and ID with IE fittings. 

C. Asbestos cement 5A and 5C and fittings laid on a continuous granular bed. 

D. Clay pipe and fittings 5E laid on a continuous granular bed. 

E. Concrete pipe 5K in yard areas and not under permanent streets, laid on a continuous 
granular bed. 

F. Concrete 5M and 5N and fittings. 

G. Plastic 6A, 6B(1), 6B(3), 6C(1), 6C(2), and 6C(3) and corresponding fittings must be laid 
on a continuous granular bed. Installation must comply with ASTM D2321. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0560 PLUMBING CODE 32 



H. Bitumini zed-fiber drain and sewer pipe 50, laid on a continuous granular bed. 

I. Fiberglass pipe 7A for pressure sewers. Installation must be in accordance with the 
manufacturer's requirements, recommendations, and guidelines. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 9 SR 1557; 23 SR 686 

Posted: July 31, 2007 

4715.0540 STORM WATER AND YARD DRAINAGE (OUTSIDE FOUNDATION WALLS). 

For storm water and yard drainage outside foundation walls the following materials may be used: 

A. those materials specified in part 4715.0530; 

B. corrugated, aluminized steel 2F. This material may not be used in any area requiring testing 
in accordance with part 4715.2820. Installation must comply with ASTM A798; 

C. corrugated high density polyethylene 6C(4) and approved joints. Installation must comply 
with ASTM D2321; and 

D. corrugated plastic 6B(5). Installation must comply with ASTM D2321. 
Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686; 28 SR 146 
Posted: July 31, 2007 

4715.0550 STORM WATER OR CLEAR WATER DRAINAGE (WITHIN BUILDINGS 
UNDERGROUND). 

For storm water or clear water drainage within buildings underground: 

A. Approved materials shall be as specified in part 4715.0570 with the following addition. 
B. Concrete 5M and 5N and fittings. 
Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

4715.0560 STORM WATER OR CLEAR WATER DRAINAGE (WITHIN BUILDINGS ABOVE 
GROUND). 

For storm water or clear water drainage within buildings above ground, materials shall be as specified 
in part 4715.0580. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



33 PLUMBING CODE 4715.0590 

4715.0570 SOIL AND WASTE PIPING UNDERGROUND OR EMBEDDED. 

For soil and waste piping, except special wastes, underground or embedded in masonry construction 
the following materials may be used: 

A. Cast iron lA or IB and fittings, and hubless cast iron IK; 

B. Cast iron IC or ID with IE fittings; 

C. Steel pipe 2C(b), stainless; 

D. Lead 4A pipe with wiped joints, fittings 4C; and 

E. Plastic 6A, 6B(1), 6B(2), 6B(3), or 6B(4) and corresponding fittings must be laid on a 
continuous granular bed. Installation must comply with ASTM D2321. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 9 SR 1557; 23 SR 686 

Posted: July 31, 2007 

4715.0580 SOIL AND WASTE PIPING ABOVE GROUND. 

For soil and waste piping, except special wastes, above ground, the following materials may be used: 



ground. 



A. Cast iron 1 A and IB and fittings, and hubless cast iron IK. This pipe may be uncoated above 

B. Cast iron IF with IJ fittings. 

C. Steel pipe 2A, wrought iron 2B with IJ fittings, and stainless 2C(b). 

D. Copper 3F, 3H, 3J (hard temper only), and 3K with 30 fittings except these materials shall 
not be used to receive the wastes from urinals nor wastes from water closets in battery. These materials are 
not recommended for use in buildings served by septic tank sewage disposal systems. 

E. Lead 4A with wiped joints and fittings 4C. 

F Plastic 6A, 6B(1), 6B(2), 6B(3), or 6B{4) with corresponding fittings may be installed except 
that no horizontal drain may exceed 35 feet in total length. No stack may exceed 3 5 feet in total height unless 
an approved expansion and contraction joint is installed at intervals not to exceed 35 feet. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 9 SR 1557; 15 SR 76; 23 SR 686 

Posted: July 31, 2007 

4715.0590 VENT PIPING BELOW GROUND. 

For vent piping below ground, the following materials may be used: 

A. Cast iron lA and IB and fittings, and hubless cast iron IK; 

Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0600 PLUMBING CODE 34 

B. Cast iron IF with fittings and with IH fitting; 

C. Steel pipe 2C(b), stainless; 

D. Brass 3A or 3B with 3C fittings; 

E. Copper 3F or 3B with 3C fittings; 

F. Copper 3L with 3C fittings; 

G. Copper 3M with fittings; and 

H. Plastic 6A, 6B(1), 6B(2), 6B(3), or 6B(4) with corresponding fittings. 
Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 
History: 9 SR 1557; 23 SR 686 
Posted: July 31, 2007 

4715.0600 VENT PIPING ABOVE GROUND. 

For vent piping above ground, the following materials may be used: 

A. Cast iron lA and IB and fittings, and hubless cast iron IK (pipe may be uncoated); 

B. Cast iron IF with IH fitting; 

C. Steel 2A pipe, wrought iron 2B with IH fitting, and stainless 2C(b); 

D. Brass 3A or 3B with 3C fittings; 

E. Copper 3F, 3H, 3J, and 3K, with 3N or 30 fittings, except see part 4715.0580, item D; 
F Copper pipe 3L with 3C fittings; 

G. Copper pipe 3M with 3M fittings; and 

H. Plastic 6A, 6B(1), 6B(2), 6B(3), or 6B{4) with corresponding fittings may be installed 
except that no horizontal vent may exceed 35 feet in total length. 

No vent stack or stack vent may exceed 35 feet in total height unless an approved expansion and 

contraction joint is installed at intervals not to exceed 35 feet. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 
History: 9 SR 1557; 23 SR 686 
Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



35 PLUMBING CODE 4715.0630 

4715.0610 SPECIAL WASTES. 

For special wastes, the following materials may be used: 

A. The following corrosion resistant materials are acceptable for chemical waste and vent 
systems: stainless steel 2C(b), chemically resistant glass pipe 5H, high silicon content cast iron IG, 
and chemically resistant plastic pipe 6S, 6T, or 6U. Use of any other materials must be approved by 
the administrative authority, who shall grant approval if the applicant can show that the material in 
question is as resistant to corrosion as are those listed above. The installation shall be in accordance with 
manufacturer's installation recommendations. If 6S, 6T, or 6U is used, horizontal piping may not exceed 
35 feet in total length; and stacks may not exceed 35 feet in total height unless an approved expansion and 

contraction joint is installed at intervals not to exceed 35 feet. 

B. pressure wastes or nonpressure wastes which are completely exposed or accessible, and 
which discharge indirectly to the drainage system may be of any materials in part 4715.0420, subpart 3, 
with due regard to the type of liquid being wasted. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 9 SR 1557; 23 SR 686; 28 SR 146 

Posted: July 31, 2007 

4715.0620 SUBSOIL DRAINS. 

All materials listed in part 4715.0570 plus asbestos cement 5D, clay 5G, cement 5J, and cement 5L, 
perforated bituminized fiber pipe for general drainage 5P, and plastic 6A, 6B, 6C, and 6W, may be used for 
subsoil drains. 

Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326.37 to 326.45 

History: 15 SR 76; 28 SR 146 

Posted: July 31, 2007 

4715.0630 SPECIAL MATERIALS. 

Subpart 1. Sheet lead. Sheet lead for the following uses shall weigh not less than: 

A. general use, four pounds per square foot; 

B. safe pans, four pounds per square foot; and 

C. flashings for vent pipes, three pounds per square foot. 

Subp. 2. Lead bends and traps. The walls of lead bends and traps shall be at least one-eighth inch 
thick. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0700 PLUMBING CODE 36 

Subp. 3. Sheet copper. Sheet copper for the following uses shall weigh not less than: 

A. general use, 12 ounces per square foot; and 

B. flashing for vent pipes, eight ounces per square foot. 

Subp. 4. Floor flanges. Floor flanges for water closets or similar fixtures shall be not less than 
one-eighth inch thick for brass; one-fourth inch thick and not less than two inch caulking depth for cast iron 
or galvanized malleable iron. 

If of hard lead, they shall weigh not less than one pound nine ounces, and be composed of lead 
alloy with not less tiian 7.75 percent antimony by weight. Flanges shall be soldered or threaded into other 

metal. Closet screws and bolts shall be of noncorrodible material. 

Subp. 5. Flush pipes and fittings. Flush pipes and fittings shall be of nonferrous material. When of 
brass or copper tubing, the material shall be not less than No. 20 U.S. gauge. 

Subp. 6. Brass tubing traps and trap arms. All brass tubing used for traps and trap arms shall 
be not less than 17 gauge (.045 inches) in thickness. Nuts used with brass tubing shall be of brass or other 
noncorrodible material. 

Subp. 7. Plastic tubular traps, plastic (ABS and PVC) tube and tubular fittings for waste 
connections. All tubular fittings must comply with the requirements of ASTM Standard F 409. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0640 FIXTURE MATERIALS. 

Plumbing fixtures shall have smooth, impervious surfaces, be free from defects and concealed surfaces. 
All receptacles used as water closets, urinals, or otherwise, for the disposal of human excreta, shall be 
vitreous china, or other material acceptable to the administrative authority, except trough urinals may be cast 
iron, enameled on the inside. Drinking fountains shall be constructed of impervious nonoxidizing material 
and shall be so designed that they may be easily cleaned. Plumbing fixtures shall conform to the applicable 
commercial standards, where such standards exist. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

JOINTS AND CONNECTIONS 

4715.0700 TIGHTNESS. 

Joints and connections in the plumbing system shall be gastight and watertight for the pressure required 
by test, with the exception of those portions of perforated or open joint piping which are installed for the 
purpose of collecting and conveying ground or seepage water. Portions of storm sewers that do not require 
testing as provided in part 4715.2820 must be constructed with a code-approved type of pipe and joint that 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



37 PLUMBING CODE 4715.0740 

has been certified by the manufacturer to be able to pass the air test specified in part 4715.2820, or an internal 
hydrostatic pressure often pounds per square inch for ten minutes with no leakage. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686 

Posted: July 31, 2007 

TYPES OF JOINTS FOR PIPING MATERIAL 

4715.0710 ASBESTOS CEMENT SEWER PIPE JOINTS. 

Joints in asbestos cement pipe shall be made with sleeve couplings of the same composition as the 
pipe, sealed with rubber rings. Joints between asbestos cement pipe and metal pipe shall be made by means 
of an adapter coupling caulked as required in part 471 5.0740. No adapted coupling shall be used that does 
not have a center ridge. Pipe must not be able to pass through the coupling. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0720 BITUMINIZED FIBER DRAIN PIPE JOINT. 

Pipe and bends shall be provided with accurately machined or molded tapered joints, and a taper sleeve 
coupling shall be provided for each length of pipe and for each bend. The slope of the taper in both pipe and 
coupling shall be two degrees. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0730 BURNED LEAD JOINTS. 

Burned (welded) lead joints shall be fused together to form a uniform weld at least as thick as the lead 
being joined. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0740 CAULKED JOINTS. 

Caulked joints for cast-iron bell and spigot soil pipe shall be firmly packed with oakum or hemp and 
filled with molten lead not less than one inch deep and shall extend not more than one-eighth inch below 
rim of hub. No paint, varnish, or any other coatings shall be permitted on the jointing material until after 
the joint has been tested and approved. Lead shall be caulked tight. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0790 PLUMBING CODE 38 



4715.0750 CEMENT MORTAR JOINTS. 

Except for repairs and connections of existing lines constructed with such joints, cement mortar joints 
are prohibited. Where permitted, cement mortar joints shall be made in the following manner: A layer of 
jute or hemp shall be inserted into the base of the annular joint space and packed tightly to prevent mortar 
from entering the interior of the pipe or fitting. Not more than 25 percent of the annular space shall be used 
for jute or hemp. The remaining space shall be filled in one continuous operation with a thoroughly mixed 
mortar composed of one part cement and two parts sand, with only sufficient water to make the mixture 
workable by hand. Additional mortar of the same composition shall then be applied to form a one to one 
slope with the barrel of the pipe. The bell or hub of the pipe shall be left exposed and when necessary the 
interior of the pipe shall be swabbed to remove any mortar or other material which may have found its way 
into such pipe. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0760 COLD JOINT COMPOUND, TAR BASE. 

Cold joint compound (tar base) for clay and concrete pipe shall not be water absorbent, and shall bond 
itself to vitrified clay and concrete pipe. Half of the joint must be packed with oakum, and the remainder 
with cold tar compound. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0770 FLARED JOINTS. 

Flared joints for soft copper water tubing shall be made with fittings meeting approved standards. (See 
part 4715.0420, subpart 3.) The tubing shall be reamed and expanded with proper flaring tools. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0780 GASKET TYPE JOINTS. 

Resilient rubber joints for clay or concrete: Flexible joints between lengths of clay or concrete pipe 
may be made by using approved resilient or rubber materials, both on the spigot end and in the bell end of 
the pipe. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0790 HOT-POURED JOINTS. 

Hot-poured compound for clay or concrete sewer pipe, or other materials, shall not be water-absorbent, 
and when poured against a dry surface shall have a bond of not less than 100 pounds per square inch. All 
surfaces of the joint shall be clean and dried before pouring. If wet surfaces are unavoidable, a suitable 
primer shall be applied. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



39 PLUMBING CODE 4715.0800 

The compound shall not soften sufficiently to destroy the effectiveness of the joint when subjected 
to a temperature of 160 degrees Fahrenheit nor soluble in any of the waste carried by the drainage system. 
Approximately 25 percent of the joint space at the base of the socket shall be filled with jute or hemp. A 
pouring collar, rope, or other device shall be used to hold the hot compound when pouring. Each joint shall 
be poured in one operation until the joint is filled. Joints shall not be tested until one hour after pouring. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0800 MECHANICAL JOINTS. 

Subpart 1. Mechanical joints for cast iron and steel water pipe. Mechanical joints in cast iron and 
steel water pipe must be made by means of a flanged collar and rubber ring gasket, secured by the use of an 
adequate number of steel bolts. The rubber sealing ring must conform to ANSI-A21.il (AWWA-Cll). 

Subp. 2. Mechanical joints in cast iron soil pipe. Mechanical joints in cast iron soil pipe shall be 
made by means of a preformed molded rubber ring, secured by pulling the pipe and fittings together in such 
a way as to compress the molded rubber ring in a manner that will assure a gas and water tight joint. The 
rubber sealing ring shall conform to ASTM 564-65 requirements. 

Subp. 3. [Repealed by amendment, 9 SR 1557] 

Subp. 4. Mechanical joints in hubless cast iron soil pipe. Mechanical Joints for hubless cast iron 
soil pipe and fittings may be made by using a neoprene sleeve and stainless steel retaining band as specified 
in CISPI standard 301, by using a transition fitting made of elastomeric material (ASTM C 425 and ASTM 
C 564) and 300 series stainless steel bands and bolts, or by using a two-part coupling whose housing is 
fabricated of grey-cast iron (ASTM A 48), with a coupling gasket made of neoprene rubber (ASTM C 564 
or CSA/CAN 3-B70), and coupling bolts and nuts made of 18-8 stainless steel. 

Subp. 5. Mechanical pipe couplings and fittings. Couplings must be made with the housing 
fabricated in two or more parts of ductile or malleable iron castings in accordance with Federal Specification 
QQ-I-666C, Grand 11, or with ASTM A47 or ASTM A339. The coupling gasket must be molded synthetic 
rubber, per ASTM D-735-61, Grade No. R615BZ. Coupling bolts must be oval neck track head type with 
hexagonal heavy nuts, per ASTM-A-183-60, or ASTM A325. 

Pipe fittings used with these pipe couplings must be fabricated or malleable iron castings in 
accordance with Federal Specifications QQ-I-666c, Grade 11, or with ASTM A47; ductile iron ASTM 
A339; segweld steel ASTM53 or A106; or lAPMO-approved copper fittings with rolled grooves intended 
to be used together with copper tubing widi cold rolled grooved ends. 

These couplings and fittings may be used above ground, for storm drains and leaders, and for water 
distribution pipe provided exposed parts in contact with water are galvanized, and may be used below 
ground for water distribution if couplings and fittings are galvanized and the exposed grooves are coal tar 
enamel coated and wrapped. 

Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0810 PLUMBING CODE 40 

Saddle-type fittings secured by steel electroplated U-bolts may be used for aboveground water 
distribution, if the fittings are galvanized, include a collar fitting into the pipe opening with a gasket, 
and have lAPMO approval. 

All grooving of galvanized pipe must be by the cut groove method. 

Subp. 6. Extracted mechanical joint. An extracted mechanical joint in copper water distribution 
pipe must be made by drilling through copper pipe and on retraction must extract a cup shaped extruded 
collar. The height of the collar must be at least three times the thickness of the copper tube wall and the 
radius of the extruded collar must be the same thickness as the copper tube wall from which it is being 
extruded. The joining branch tube must be contour-notched and a retaining dimple must be made before 
insertion into the extracted collar or another acceptable method must be used to provide proper insertion 
depth. The joint must be brazed with a brazing material meeting the requirements of part 471 5.0820. The 
joint may be used above ground only. 

Subp. 6a. Field formed coupling for copper tubing. A field formed coupling in copper water 
distribution pipe must be made by first annealing the area of the tubing where expansion is desired, and 
then using a hand tube expander to expand the tube end to accept tubing of the same type and size. Joint 
clearances must be from .001 to .005 inches, and suitable for the brazing filler metal used. The depth of the 
expanded area must be as recommended by the tube expander manufacturer, but in all cases must be at least 
four times the wall thickness of the tubing. All joints must be brazed in accordance with the requirements 
of part 4715.0820. The couplings must be used above ground only. 

Subp. 7. Mechanical tee coupling for steel pipe. Couplings utilizing an explosive charge and an 
internal cutting mechanism may be used to join galvanized steel pipe only. All portions of the coupling 
exposed to water must be of galvanized steel construction acceptable for contact with potable water. The 
coupling must only be used above ground and only in areas that are accessible. The coupling must be 
attached to the steel pipe by use of four alien screws which must be torqued in accordance with the coupling 
manufacturer's recommendation. 

Statutory Authority: MS s 16B.61; 16B.62; 326.37 to 326.45 

History: 9 SR 1557; 15 SR 76; 19 SR 590 

Posted: July 31, 2007 

4715.0805 PUSH-ON JOINTS. 

Push-on joints may be used in cast iron and ductile iron water service pipe located underground outside 
the building, and must comply with ANSI-A21. 11-85. Lead-tipped gaskets are prohibited. 

Statutory Authority: MSs 16B.61; 16B.62; 326.37 

History: 15 SR 76; 19 SR 590 

Posted: July 31, 2007 

4715.0810 PLASTIC JOINTS. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



41 PLUMBING CODE 4715.0820 



Subpart 1 . Joint methods. Every joint in plastic piping must be made with approved fittings using 
solvent welded connections, fusion welded connections, insert fittings with metal clamps and screws of 
corrosion-resistant material or approved crimp rings, threaded joints according to accepted standards, 
or special lAPMO listed fittings of other types. Large diameter water service pipe may have approved 
elastomeric-gasketpush-ontype joints which comply with ASTMD 3139. All solvent materials must meet 
approved recognized standards. Expansion and contraction joint materials and dimensions must conform 
to ASTM D 2661 or ASTM D 2665 and shall be of an approved type. Gasketed sewer fittings must comply 
with ASTM F1336. 

Subp. 2. Primer. Solvent weld joints in PVC and CPVC pipe must include use of a primer of 
contrasting color to the pipe and cement. Primers must comply with the National Sanitation Foundation 
(NSF) Standard Number 14. A mechanical method of preparing PVC or CPVC pipe for solvent cement is 
not acceptable in lieu of using a primer. 

Exception: A one-step solvent cement complying with ASTM F493 and ASTM D2846 may be 

used for CPVC pipe. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 
History: 11 SR 1405; 15 SR 76; 19 SR 590; 23 SR 686 
Posted: July 31, 2007 

4715.0815 JOINTS IN CHEMICAL WASTE PIPE. 

Joints for chemical waste and vent piping must be of corrosion resistant material, or coated or wrapped 
with a corrosion resistant material, and designed for use with the type of piping material selected. All joint 
materials and methods must be as approved by the administrative authority. 

Statutory Authority: MS s 326.37 to 326.45 

History: 9 SR 1557 

Posted: July 31, 2007 

4715.0820 SOLDERED OR BRAZED JOINTS. 

Joints with copper tube with solder joint fittings must be soldered or brazed. Copper tubing must 
be reamed out to the fiill interior tubing dimension before soldered or brazed joints are made. Surfaces 
to be soldered or brazed must be thoroughly cleaned. Joints to be soldered must be properly fluxed with 
noncorrosive paste or liquid type flux complying with ASTM Standard B813-00. Solder and flux used in 
potable water systems must not contain more than 0.2 percent lead. Solder used for joints must have a 
nominal composition of 50 percent tin and 50 percent lead, 95 percent tin and five percent antimony, or 
96 percent tin and four percent silver, conforming to ASTM Standard Specification for soft solder metal 
B32-94, except that 50 percent tin and 50 percent lead solder must not be used in potable water systems. 
Alternative solders may be used if specifically approved by the administrative authority after review of 
testing laboratory or listing agency documentation. Brazing must be done using a brazing filler metal which 
is manufactured for the particular application, and using methods specified by the filler metal manufacturer. 

Statutory Authority: MS s 16B.59 to 16B. 73; 326.37 to 326.45 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0850 PLUMBING CODE 42 

History: 11 SR 1405; 15 SR 76; 28 SR 146 
Posted: July 31, 2007 

4715.0830 THREADED JOINTS - SCREWED JOINTS. 

Threaded joints shall conform to American National taper pipe thread, ASA B2. 1-1945 or FS 
GGG-P-351a. All burrs shall be removed. Pipe ends shall be reamed out to size of bore and chips removed. 
Pipe joint compound shall be used on male threads only. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0840 WIPED JOINTS. 

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 the 
joint not less than three-fourths inch, and a minimum thickness at the thickest part of the joint of not less than 
three-eighths inch. Joints between lead pipe and cast iron, steel, or wrought iron shall be made by means of 
a caulking ferrule, soldering nipple, or bushing. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0850 USE OF JOINTS. 

Subpartl. Bituminized fiber pipe joints. Joints in bituminized fiber pipe shall be made as provided 
for in part 4715.0720. 

Subp. 2. Cast-iron pipe. Joints in cast iron shall be either caulked or screwed, as provided in parts 
4715.0740, 4715.0830, and 4715.0840. 

Subp. 3. Cast-iron soil pipe. Joints in cast-iron soil pipe may be made by means as provided in part 
4715.0740 or 4715.0800, subpart 2. 

Subp. 4. Clay sewer pipe. Joints in clay sewer pipe, or between such pipe and metal pipe shall be 
made as provided in parts 4715.0750, 4715.0760, 4715.0780, and 4715.0790. 

Subp. 5. Concrete sewer pipe. Joints in concrete sewer pipe, or between pipe and metal pipe, shall 
be made by means as provided in parts 4715.0750, 4715.0760, 4715.0780, and 4715.0790. 

Subp. 6. Copper water tube. Joints in copper water tubing shall be made either by the appropriate 
use of approved brass or wrought copper water fittings properly soldered or brazed; by means of approved 
flared fittings as provided in part 4715.0770; or by means of press type copper and copper alloy fittings on 
aboveground water distribution copper tubing, sizes 1/2-inch to 4-inch, installed in accordance with lAPMO 
Standard PS 117-2002. 

Subp. 7. Lead to cast iron, wrought iron and steel. Joints between lead and cast iron, wrought 
iron, or steel shall be made by means of wiped joints to a caulking ferrule, soldering nipple, or bushing as 
provided in part 4715.0840. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



43 PLUMBING CODE 4715.0860 



Subp. 8. Plastic pipe joints. Joints in plastic pipe or between plastic and cast iron, steel, brass, or 
copper pipe shall be made as provided in part 4715.0810. 

Subp. 9. Threaded pipe to cast iron. Every joint between wrought iron, steel, brass, copper, and 
cast-iron pipe shall be either caulked or threaded joints as provided in parts 4715.0740, 4715.0830, and 
4715.0840 and shall be made with approved adapter fittings. 

Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326.37 to 326.45 

History: 28 SR 146 

Posted: July 31, 2007 

4715.0860 SPECIAL JOINTS. 

Subpart 1. Bituminized fiber to other types of pipe. When connecting bituminized fiber pipe to 
other types of materials, only approved types of fittings and adapters designed for the specific transition 
intended shall be used. 

Subp. 2. Cast-iron to copper tube. Caulked joints between copper tubing and cast-iron soil pipe 
shall be made by means of brass or copper ferrules or other approved adapter fittings. 

Subp. 3. Copper tubing to threaded pipe joints. Joints from copper tubing to threaded pipe shall 
be made by the use of brass or copper adapter fittings. The joint between the copper pipe and fitting shall 
be properly soldered, brazed, or flared. 

Subp. 4. Expansion joints. Every expansion joint shall be of an approved type and the material 
used in its manufacture shall be compatible with the type of piping in which it is installed. Every expansion 
joint, other than an expansion loop, shall be accessible. (Also see part 4715.2770) 

Subp. 5. Slipjoints. In drainage piping, slip joints shall be used only on the inlet side of the trap or in 
the trap seal. Every slip joint shall be made using approved packings of gasket material or approved ground 
joint brass compression rings. Ground faced connections which allow adjustments of tubing but provide a 
durable rigid joint when made up shall not be considered as a slip joint. 

Subp. 6. Transition couplings. A transition coupling is one which is to be used when pipes 
made of different materials are to be joined. A transition coupling may be made of elastomeric materials 
(ASTM C 425 and ASTM C 564) and 300 series stainless steel bands and bolts, except that an exterior 
corrosion-resistant shield to prevent outward expansion of the coupling must be included on above-ground 
installations. Any transition coupling joining plastic to plastic, copper to copper, or galvanized to 
galvanized, must be approved by the administrative authority. 

Subp. 7. Flexible joints for roof drain connections. A flexible bellows-type joint may be used to 
join roof drains to approved storm drain piping. The flexible joint must be made of a bellowed neoprene or 
thermoplastic rubber sleeve and secured by 300 series stainless steel band and bolts. The joint must not be 
concealed nor installed at an angle of more than 45 degrees from the vertical. 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 9 SR 1557; 15 SR 76 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.0900 PLUMBING CODE 44 



4715.0870 FLANGED FIXTURE CONNECTIONS. 

Fixture connections between drainage pipes and water closets, pedestal urinals, and earthenware trap 
standards shall be made by means of brass, plastic, or iron flanges, caulked, soldered, solvent welded, or 
screwed to the drainage pipe in accordance with the manufacturer's recommendations and approved by 
the administrative authority. The connection shall be bolted, with an approved gasket, washer, or setting 
compound between the earthenware and the connection. Floor flanges of other equivalent materials may be 
used when approved by the administrative authority. 

The bottom of the floor flange shall be set on the top of the finished floor or on a structurally firm 
base. Closet bends or stubs must be cut off so as to present a smooth surface, even with the top of the closet 
flange. Use of commercial putty or plastic as fixture setting compound is prohibited. 

Statutory Authority: MS s 16B.62; 326.37 to 326.45 

History: 19 SR 590 

Posted: July 31, 2007 

4715.0880 PROHIBITED JOINTS AND CONNECTIONS. 

See part 4715.2420. 
Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

4715.0890 INCREASERS AND REDUCERS. 

Brass or cast-iron body cleanouts shall not be used as a reducer or adapter from cast-iron soil pipe 
to steel or wrought iron pipe. Where different sizes of pipe or pipes and fittings are to be connected, the 
proper size increasers, reducers, or reducing fittings shall be used between the two sizes. Hexagon screwed 
bushings shall not be used in drainage piping. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

TRAPS AND CLEANOUTS 

4715.0900 FIXTURE TRAP REQUIREMENTS. 

Each plumbing fixture, except those having an integral trap, shall be separately trapped by a water seal 
trap, installed as close to the fixture as possible, and in such a manner as to be readily accessible for cleaning 
and repairing. 

A single trap may serve a two or three compartment sink or laundry tray. The trap shall be located 
not more than 30 inches from each compartment outlet. The vertical distance between the fixture outlet and 
the trap weir shall be as short as possible, but in no case more than 24 inches in length. 

No food waste disposal unit shall be installed in a set of restaurant, commercial, or industrial sinks, 
served by a single trap. Each such disposal unit shall be individually trapped and connected to a separate 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



45 PLUMBING CODE 4715.0940 



waste opening. Each trap shall have the manufacturer's name or identification stamped legibly thereon and 
each tubing trap shall show the gauge of the tubing used in its manufacture. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0910 TRAPS DESCRIBED. 

Every fixture trap shall be self-cleaning. Traps for bathtubs, lavatories, sinks, showers, laundry tubs, 
urinals, drinking fountains, and similar fixtures, shall be of standard design and weight and shall be of lead, 
brass, cast iron, or other approved materials, and have a smooth and uniform interior waterway. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0920 TRAP PROTECTION. 

All fixture traps, except as otherwise provided in this code, shall be protected against siphonage and 
back pressure by means of a properly installed vent pipe. The vent shall be so located that the developed 
length from the fixture trap to the vent shall not exceed the distance given in part 4715.2620, subpart 4. 

The vent pipe opening from a soil or waste pipe, except for water closets and similar fixtures, shall 
not be below the weir of the trap. The trap arm direction may be changed by the use of not more than two 
45 degrees or one 90 degrees long turn elbows. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0930 SIZES OF TRAPS. 

The minimum size (nominal interior diameter) of a trap for a given fixture shall be determined by part 
4715.2300, subpart 3. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0940 SLIP JOINTS AND UNIONS. 

Union joints on the sewer side of the trap shall be ground faced, shall be accessible, and shall provide 
a rigid connection when made up tight. Slip joints shall be used only on the inlet side of the trap or in the 
trap seal. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.1000 PLUMBING CODE 46 



4715.0950 TRAP SEALS. 

Fixture traps shall have a water seal depth of not less than two inches and not more dian four 
inches, except where, under special conditions, a trap with a deeper seal may be found necessary by the 
administrative authority. 

The horizontal length of the seal of any fixture trap shall not exceed six inches where the waste pipe 
required is two inches or less in diameter. 

Traps shall be set true and level with respect to their water seals and where necessary shall be protected 
from freezing. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0960 TRAPS PROHIBITED. 

No form of trap which depends for its seal upon the action of movable parts or concealed interior 
partitions shall be used. 

Full "S" traps, bell traps, and crown vented traps, are prohibited. 

Traps shall not be made up with fittings, unless authorized by the administrative authority. 

Water-cooled grease traps are prohibited. 

No fixture shall be double-trapped. 

Drum traps shall be installed only when permitted by the administrative authority for special 
conditions (laboratory tables, dental chairs, etc.). 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.0970 TRAP CLEANOUTS. 

An accessible trap is considered a cleanout for the fixture branch serving the individual fixture. 
Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

DRAINAGE PIPE CLEANOUTS 

4715.1000 LOCATION. 

There shall be at least two cleanouts in the building drain, one at or near the base of the stack and one 
near the connection between the building drain and the building sewer. The cleanout at the outside wall may 
be inside or outside the building, and shall be made with a full "Y" branch fitting and shall extend at least 
two inches above grade or finished floor, except that the administrative authority may grant permission to 
use a flush cover in trafl&c areas. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



47 PLUMBING CODE 4715.1030 



A cleanout which is easily accessible shall be provided at or near the foot of each vertical soil or 
waste stack and each vertical storm water leader. 

Each horizontal branch drain pipe shall be provided with a cleanout at its upper terminal, except that 
a fixture trap or a fixture with an integral trap, readily removable without disturbing concealed piping, may 
be accepted as a cleanout equivalent for this purpose. 

A trap opening from a lavatory, drinking fountain, luinal, sink, or similar fixture may serve as a 
cleanout for a horizontal branch drain up to two inches in size, if the drain opening is not more than one pipe 
size smaller than the horizontal branch drain. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686 

Posted: July 31, 2007 

4715.1010 SIZE OF CLEANOUTS. 

The cleanout shall be of the same nominal size as the pipes they serve up to four inches in diameter 
and not less than four inches for larger piping. 

The distance between cleanouts in horizontal piping shall not exceed 50 feet for three inch or less in 
size and not over 100 feet for four inch and over in size. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1020 CLEANOUT MATERIALS. 

The bodies of cleanout ferrules shall be made to standard pipe sizes, conform in thickness to that 
required for pipes and fittings of the same material and extend not less than one-fourth inch above the hub. 
The cleanout cover or plug shall be of brass, cast iron, or approved plastic and be provided with a raised nut 
or recessed socket for removal. 

Neoprene or nordel rubber with a plastic disc and a single stainless steel {300 series) band may be 
used for a cleanout cover provided that it is exposed and readily accessible. 

Statutory Authority: MS s 16B.62; 326.37 to 326.45 

History: 19 SR 590 

Posted: July 31, 2007 

4715.1030 CLEANOUTS TO BE ACCESSIBLE. 

Each cleanout, unless installed under an approved cover plate or left flush with the finished floor, shall 
be at least two inches above grade, readily accessible, and shall not be covered with cement, plaster, or other 
permanent finish material. Where a soil stack cleanout is located within ten feet of where the building drain 
leaves the building, the cleanout at the outside wall may be eliminated. 

Statutory Authority: MS s 326.37 to 326.45 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715. 1115 PLUMBING CODE 48 

Posted: July 31, 2007 

INTERCEPTORS, SEPARATORS, AND BACKWATER VALVES 

4715.1100 INTERCEPTORS AND SEPARATORS REQUIRED. 

Interceptors for oil, grease, sand, and other substances harmful or hazardous to the building drainage 
system shall be provided as stated elsewhere in these rules. 

The size, type, and location of each interceptor, and of each separator shall conform to the 
requirements of this chapter, except that units may be accepted which are engineered and manufactured 
specifically for the intended function and which are documented by the manufacturer and project design 
engineer to be properly designed and sized for the specific project, and no waste other than those requiring 
treatment or separation shall discharge into any interceptor. 

Statutory Authority: MS s 16B.62; 326.37 to 326.45 

History: 19 SR 590 

Posted: July 31, 2007 

4715.1110 GREASE INTERCEPTORS FOR COMMERCIAL BUILDINGS. 

A grease interceptor of sufficient size and efficiency shall be installed in the waste line leading from 
sinks, drains, or other fixtures when, in the opinion of the administrative authority, greasy wastes can be 
introduced into the drainage system in quantities that can cause line stoppage. Grease interceptors shall be 
placed as near as possible to the fixture and the grease interceptor shall be vented. No food waste disposer or 
dishwashing machine shall discharge into the building drainage system through a grease interceptor. Sinks 
or other fixtures served by grease interceptors shall be trapped and vented ahead of the grease interceptor. 

Grease interceptors, when used, shall have a grease retention capacity in pounds of grease, of at least 
twice the flow-through rate, in gallons per minute. 

Grease interceptors shall be equipped with devices to control the rate of water flow through the 
interceptors so that it does not exceed the rated flow of the interceptor. Air openings on flow control devices 
must connect to the plumbing vent system. 

Statutory Authority: MS s 16B.62; 326.37 to 326.45 

History: 19 SR 590 

Posted: July 31, 2007 

4715.1115 EXTERIOR GREASE INTERCEPTORS. 

Subpart 1. Authorized uses. An exterior grease interceptor may be installed if it is acceptable to 
the administrative authority. Only fixtures that discharge greasy waste may be piped to the interceptor. 
Dishwashing machines and food waste grinders may not be routed through the interceptor unless the routing 
is acceptable to the administrative authority. 

Subp. 2. Construction. The grease interceptor tank must be readily accessible for inspection and 
maintenance. The tank must comply with parts 5 and 6 of ASTM Standard C1227-98. The name of the tank 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



49 PLUMBING CODE 4715.1115 

manufacturer, the liquid holding capacity, and compliance with ASTM C1227-98 for the tank construction 
must be permanently affixed to the tank. 

The grease interceptor must allow a detention time of at least 30 minutes and must be protected 
from freezing. The landscape must be bermed to divert runoff. The tank must be protected to prevent 
loadings that may lead to structural collapse. 

The materials used in piping to the inlet of the tank must comply with building drain requirements. 
The tank outlet piping may comply with building sewer materials, unless the outlet piping reenters the 
building, in which case, the materials must be approved for building drain to point of connection to 
building sewer. 

Baffles or tees must be provided at the inlet and outlet of the tank. The invert of the inlet must be at 
least two inches above the invert of the outlet. The inlet baffle/tee must extend at least six inches below 
the liquid level, and the outlet baffle/tee must extend at least 12 inches below the liquid level of the tank. 
Both inlet and outlet baflfles/tees must extend at least six inches above the liquid level. Baffles, tees, and 
fasteners must be made of plastic or stainless steel. 

The tank and baffle design must allow for continuous circulation of air throughout the tank. Vents, 
if provided, must be at least two inches in diameter, located within the building within ten feet of the 
interceptor, and must be labeled as the exterior grease interceptor vent. The vent must rise within 45 
degrees of the vertical to a point at least six inches above the tank before offsetting horizontally. 

Inspection pipes, at least four inches in diameter, must be provided above the baffles/tees. A 
manhole, at least 24 inches in diameter, must also be provided. The manhole cover must be locked in 
place, marked with a warning to not enter without proper equipment, and be provided with a label 
identifying the vessel as the exterior grease interceptor. 

The inlet and outlet pipes must be connected to the tank with a sealed flexible joint to accommodate 
pipe movement. A cleanout, at least four inches in diameter, must be provided on the discharge line 
from the interceptor. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715. 1120 PLUMBING CODE 50 



Subp. 3. Inspection, testing, and records. After installation, the tank must pass a manometer test 
with one inch of water column for five minutes, or a vacuum test with two inches of mercury for 60 minutes. 
The grease interceptor must be inspected at least once every three months, and must be pumped and cleaned 
regularly. Records of inspection and maintenance must be kept. The administrative authority shall set the 
frequency, duration, and availability of the inspections, cleaning, and record-keeping information. 

Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326.37; 326.40 

History: 28 SR 146 

Posted: July 31, 2007 

4715.1120 OIL AND FLAMMABLE LIQUIDS SEPARATOR. 

Enclosed garages of over 1,000 square feet or housing more than four motor vehicles, repair garages, 
gasoline stations with grease racks, work or wash racks, auto washes, and all buildings where oily and/or 
flammable liquid wastes are produced shall have a separator installed into which all oil, grease, and sand 
bearing and/or flammable wastes shall be discharged before emptying into the building drainage system or 
other point of disposal, when floor drains or trench drains are provided. 

Exception: Private garages classified as Group U occupancies serving one- and two-family dwellings. 

Each separator shall be of watertight construction and of not less than 35 cubic feet holding capacity, 
be provided with a water seal of not less than three inches on the inlet and not less than 18 inches on the 
outlet. The minimum depth below the invert of the discharge drain shall be three feet. The minimum size of 
the discharge drain shall be four inches. The separator may be constructed of monolithic poured reinforced 
concrete with a minimum floor and wall thickness of six inches, or of iron or steel of a minimum thickness 
of 3/16 inch, protected with an approved corrosion resistant coating on both the inside and the outside. 

The separator must be provided with a nonperforated iron or steel cover and ring of not less than 24 
inches in diameter, and the air space in the top of the tank must have a three-inch vent pipe, constructed of 
approved metallic material, extending separately to a point at least 12 inches above the roof of the building. 
Drains and piping from motor vehicle areas must be a minimum of three inches in size. Drains discharging 
to an interceptor must not be trapped and must be constructed so as not to retain liquids. In motor vehicle 
wash facilities, a sand interceptor which meets the requirements of part 4715.1130, subpart 1, except that 
no water seal is permitted, may be installed to receive wastes before discharging into a flammable waste 
separator. 

No cleanout, mechanical joint, or backwater valve shall be installed inside the separator which could 
provide a bypass of the trap seal. Only wastes that require separation shall discharge into the separator, 
except that a water supplied and trapped sink may be connected to the vent of the separator. Whenever the 
outlet branch drain serving a separator is more than 25 feet from a vented drain, such branch drain shall be 
provided with a two inch vent pipe. A backwater valve shall be installed in the outlet branch drain whenever 
in the judgment of the administrative authority backflow from the building drain could occur. 

A separator must be installed to be readily accessible for service and maintenance, and must be 
maintained by periodic removal of accumulated liquids and solids from the separator. 

Statutory Authority: MS s 16B.59; 16B.61; 16B.62; 16B.64; 326.37 to 326.45 

History: 9 SR 1557; 19 SR 590; 28 SR 146 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



51 PLUMBING CODE 4715.1160 



Posted: July 31, 2007 

4715.1130 INTERCEPTORS AND SEPARATORS FOR SPECIFIC INSTALLATIONS. 

Subpart 1. Sand interceptors, commercial establishments. Sand and similar interceptors for heavy 
solids shall be so designed and located as to be readily accessible for cleaning, and shall have a water seal 
of not less than six inches. 

Subp. 2. Laundries. Commercial laundries shall be equipped with an interceptor having a wire 
basket or similar device, removable for cleaning, that will prevent passage into the drainage system of solids 
one-half inch or larger in size, string, rags, button, or other material detrimental to the public sewerage 
system. 

Subp. 3. Bottling establishments. Bottling plants shall discharge their process wastes into an 
interceptor which will provide for separation of broken glass or other solids before discharging liquid 
wastes into the drainage system. 

Subp. 4. Slaughterhouses. Slaughtering and dressing room drains shall be equipped with separators 
or interceptors approved by the administrative authority, which shall prevent the discharge into the drainage 
system of feathers, entrails, or other material likely to clog the drainage system. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1140 VENTING OF INTERCEPTORS AND SEPARATORS. 

Interceptors and separators shall be so designed that they will not become airbound if closed covers 
are used. Each interceptor or separator shall be properly vented. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1150 MAINTENANCE OF INTERCEPTORS AND SEPARATORS. 

Interceptors and separators shall be maintained in efficient operating condition by periodic removal 
of accumulated grease, scum, oil, or other floating substances, and solids, deposited in the interceptor or 
separator. 

Each interceptor and separator shall be so installed that it is readily accessible for removal of cover, 
servicing, and maintenance. If installed substantially below grade a manhole with flush manhole cover 
should be provided. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1160 BACKWATER VALVES. 

Subpart 1. Where used. Drainage piping serving fixtures that are located below the elevation of the 
curb or property line at the point where the building sewer crosses under the curb or property line, and above 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715. 1200 PLUMBING CODE 52 

the crown level of the main sewer, shall drain by gravity into the main sewer, and shall be protected from 
back flow of sewage by installing an approved backwater valve, and each such backwater valve shall be 
installed only in that branch or section of the drainage system which receives the discharge from fixtures 
located below the elevation of the curb or property line. 

Further, in every building hereafter erected or remodeled so that the erection or remodeling creates a 
new dwelling use which is located below the elevation of the point where the building sewer crosses under 
the curb or property line, all fixtures installed below such point shall be connected to a separate branch 
drain. Each such branch drain shall be protected by an approved backwater valve and a gate valve. The 
gate valve shall be located on the sewer connection side of the backwater valve. 

Further, the backwater valve and gate valve may be waived by the administrative authority 
whenever the sanitary sewer does not receive any storm water drainage and the building is located at a 
sufficient height above the public sanitary sewer so flooding by backflow will not occur, in the opinion of 

the administrative authority. 

Subp. 2. Construction of backwater valves. Backwater valves shall be constructed so that a 
mechanical seal against backflow will be provided. Backwater valves shall have all balls or bearing parts 
of noncorrodible material and shall have bolted covers and be readily accessible for cleaning. 

Subp. 3. Venting of backwater valves. Where the installation and operation of backwater valves 
interfere with the proper ventilation of the plumbing system, additional vents shall be provided so as to 
assure adequate ventilation of the plumbing system when the backwater valves are in a closed position. 

Subp. 4. Accessibility of backwater valves. Backwater valves shall be installed so their working 
parts will be readily accessible for service and repairs. If installed substantially below grade a manhole with 
flush manhole cover shall be provided. 

Statutory Authority: MS s 16B.62; 326.37 to 326.45 

History: 19 SR 590 

Posted: July 31, 2007 

PLUMBING FIXTURES 

4715.1200 CONNECTIONS TO PLUMBING SYSTEM REQUIRED. 

All plumbing fixtures and drains used to receive or discharge liquid wastes or sewage shall be connected 
to the drainage system of the building in accordance with the requirements of the code. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



53 PLUMBING CODE 4715.1220 

4715.1210 REQUIRED MINIMUM NUMBER OF FIXTURES. 

Plumbing fixtures shall be provided for the type of building occupancy and in the minimum number 
shown as required in chapter 1305, Minnesota Building Code. 

Statutory Authority: MS s 16B.59; 16B.61; 16B.62; 16B.64; 326.37 to 326.45 

History: 19 SR 590; 28 SR 146 

Posted: July 31, 2007 

4715.1215 [Repealed, 19 SR 590] 
Posted: July 31, 2007 

4715.1220 INSTALLATION OF FIXTURES. 

Subpart 1. Fixtures. Fixtures must be set level and in proper alignment with reference to adjacent 
walls. No water closet may be set closer than 15 inches from its center to any side wall or partition nor 
closer than 30 inches, center to center, between toilets. At least a 24-inch clearance must be provided in 
front of water closets. Note: The centerline of water closets used primarily by children 12 and younger 
must be a minimum of 12 inches to a maximum of 18 inches from the side wall or partition (see Minnesota 
Accessibility Code). 

No urinal may be set closer than 15 inches from the center to any side wall or partition, nor closer 
than 24 inches, center to center, between urinals. 

Wall-hung water closet bowls must be rigidly supported by a concealed metal hanger which is 
attached to the building structural members so that no strain is transmitted to the closet connector or 
any other part of the plumbing system. 

Plumbing fixtures must be so installed as to afford easy access for cleaning both the fixture and the 

area about it. Where practical, all pipes from fixtures must be run to the nearest wall. 

Subp. 2. Joints. Joints formed where fixtures come in contact with floors shall be sealed. 

Fixtures having concealed slip joint connections shall be provided with an access panel or utility 
space or other convenient access so arranged as to make the slip joint connections accessible for inspection 

and repair. 

Subp. 3. Overflows. In any fixture which is provided with an overflow, the waste shall be designed 
and installed so that the standing water in the fixture cannot rise in the overflow when the stopper is closed, 
nor shall any water remain in the overflow when the fixture is empty. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715. 1260 PLUMBING CODE 54 

The overflow from any fixture shall discharge into the drainage system on the inlet or fixture 

side of the trap. 

Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326.37 to 326.45 
History: 75 SR 76; 28 SR 146 
Posted: July 31, 2007 

4715.1230 AUTOMATIC CLOTHES WASHERS. 

A water supply line to an automatic clothes washer shall be protected against backflow by the use of 
an air gap or vacuum breaker. The discharge shall be through an air break. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1240 BATHTUBS. 

Subpart 1. Outlets. Bathtubs must have waste outlets and overflows at least one and one-half inches 
in diameter. The waste control device must be located at the tub outlet. 

Subp. 2. Whirlpool bathtubs. Whirlpool bathtubs and their installation must comply with ANSI 
112.19.7 and ANSI 112.19.8. 

Subp. 3. Drop-in bathtubs. Bathtubs which do not have a factory applied flange for installation 
against a wall are considered drop-in-type and must not be installed against a wall. 

Statutory Authority: MS s 16B.61; 16B.62; 326.37 to 326.45 

History: 75 SR 76; 19 SR 590 

Posted: July 31, 2007 

4715.1250 DISHWASHING EQUIPMENT. 

Every dishwasher in a building for public use shall discharge to the drainage system through an air 
break. If a floor drain constructed without a backwater valve is installed on the individual dishwasher branch, 
the dishwasher may be connected directly to the drainage system. The water supply to any dishwasher in 
which the supply opening is located below the spill line of the machine shall be protected with a vacuum 
breaker. 

Statutory Authority: MSs 16B.59; 16B.61; 16B.64; 326.37; 326.40 

History: 28 SR 146 

Posted: July 31, 2007 

4715.1260 DRINKING FOUNTAINS. 

Drinking fountains must be constructed of impervious nonoxidizing material and must be so designed 
that they may be easily cleaned. The water should be carried to the fixture in an independent pipe, and no 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



55 PLUMBING CODE 4715.1300 



part of the fixture must be used in conveying water to the jet. The design of the fixture must be such that no 
part of the supply pipe can be submerged in the fixture, or in the waste pipe from the fixture. The jet must 
be slanting and the orifice of the jet must be protected in such a manner that it cannot be contaminated by 
droppings from the mouth or by splashing from the basin. The orifice of the jet must be at least one inch 
above the rim of the basin. All fountains should be so designed that their proper use is self-evident. 

Installation of a combined cold water faucet and drinking fountain bubbler is prohibited for public 
use. If a drinking fountain bubbler is provided at a public use sink, it must have at least an 1 8-inch separation 
from any other faucet spout. 

Statutory Authority: MS s 163.61; 16B.62; 326.37 to 326.45 

History: 75 SR 76; 19 SR 590 

Posted: July 31, 2007 

4715.1300 FLOOR DRAINS. 

Subpart 1. Floor drain trap and strainer. A floor drain shall be considered a plumbing fixture and 
shall be provided with a trap seal and a removable strainer. The open area of the strainer shall be at least 
equal to the cross-section area of the drain line to which it connects. 

Subp. 2. Basement floor drains. Basement floor drains or floor drains installed in floors which are 
laid directly on the ground shall be provided with either an integral trap constructed with a spigot outlet or 
a "P" trap of cast iron or other approved materials compatible with the drainage pipe with a spigot outlet 
and provisions for a caulked connection to the drain body. A vacuum breaker shall be installed on the water 
supply to flush rim floor drains. 

Subp. 3. Provision for evaporation. Where floor drains are subject to evaporation, they shall be 
of the deep seal type, with a minimum water seal of three inches and may be provided with a water supply 
through an air gap, from a plumbing fixture, automatic priming device, or other approved means, to maintain 
the minimum water seal. 

Subp. 4. Venting of floor drains. Floor drain fixture branches which are less than 25 feet in length 
and connect to a vented main or branch do not require an individual vent. Floor drains not meeting these 
requirements and floor drains used for shower drains, recessed slop, or similar receptors shall be vented in 
accordance with parts 4715.2520, subparts 5 and 6, 4715.2550, subpart 3, and 4715.2620, subpart 4. 

Subp. 5. [Repealed, 19 SR 590] 

Subp. 6. Garage and parking area floor drains. Floor area drains in open parking areas, including 
open areas of parking ramps, must discharge to the storm sewer if available. Floor drains in parking areas 
which are enclosed, and floor drains in areas open or enclosed which are used for maintenance or as a vehicle 
wash bay, must discharge to the sanitary sewer if a municipal sewer is available. Oil and flammable liquid 
separators must be provided if required by part 4715.1120. 

Exception: Floor drains in private garages classified as Group U, Division 1 occupancies serving 

one- and two-family dwellings may discharge to daylight if approved by the administrative authority. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715. 1330 PLUMBING CODE 56 

History: 15 SR 76; 19 SR 590; 23 SR 686 
Posted: July 31, 2007 

4715.1305 ELEVATOR PIT DRAIN. 

An elevator pit drain must discharge to the sanitary sewer using an indirect connection that precludes 
the possibility of sewage backup into the pit. If a sump is used, it must be outside the pit with a dry pan 
drain flowing to it. 

Statutory Authority: MS s 16B.61 

History: 15 SR 76 

Posted: July 31, 2007 

4715.1310 FOOD-WASTE GRINDER UNITS. 

Domestic food-waste grinders shall be connected to a drain of not less than 1-1/2 inches in diameter. 

Commercial food-waste grinders shall be connected to a drain of sufficient size to serve the unit, but 
in no case connected to a drain of less than two inches in diameter, and shall be connected, trapped, and 
vented separately from any other fixtures or compartments. 

All food-waste grinders shall be provided with an adequate supply of water in sufficient flow rate 
to insure proper functioning of the unit. The water supply line to a commercial food waste grinder, which 
is equipped with a water rinsed funnel, shall be protected against back-siphonage by an air gap or vacuum 
breaker. 

No food-waste grinders shall be connected so as to discharge through a grease interceptor. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1320 FLUSHING DEVICES FOR WATER CLOSETS AND URINALS. 

Each water closet, urinal, clinical sink, or similar fixture shall be provided with a flushometer valve, 
flush tank, or similar device designed and installed so as to supply water in sufficient quantity and rate of 
flow to flush to the sewer the contents of the fixture to which it is connected to cleanse the fixture and refill 
the fixture trap. 

A flushing device shall serve only one fixture with the exception that a single flush tank may be used 
to flush more than one urinal provided that the flushing cycle is controlled automatically and that each urinal 
or section thereof is thoroughly flushed. Automatically controlled flushometer valves may be substituted 
for flush tanks. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1330 FLUSH TANKS. 



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57 PLUMBING CODE 4715.1360 



Subpart 1. Water supply for flush tanks. An adequate quantity of water shall be provided to flush 
and clean the fixture served. The fixture supply to a flush tank must have a shutoff valve. The water supply 
to flush tanks equipped for manual flushing shall be controlled by a float valve or other automatic device 
designed to refill the tank after each discharge and to completely shut off the water flow to the tank when the 
tank is filled to operational capacity. Provision shall be made to automatically supply water to the fixture so 
as to refill the trap seal after each flushing, the water supply to flush tanks equipped for automatic flushing 
shall be controlled by a suitable timing device. (See part 4715.1770, subpart 2.) 

Subp. 2. Overflows in flush tanks. Flush tanks shall be provided with overflows discharging to the 
water closet or urinal connected thereto and of sufficient size to prevent flooding of the tank at the maximum 
rate of water supply. Where the float valve is below the rim of the flush tank, it shall be elevated above the 
overflow and provided with a vacuum breaker or air gap. (See part 4715.2150, subpart 2, protective devices.) 

Statutory Authority: MS s 16B.62; 326.37 to 326.45 

History: 19 SR 590 

Posted: July 31, 2007 

4715.1340 FLUSHOMETER VALVES. 

Flushometers shall be installed so that they will be readily accessible for repair. Flushometer valves 
shall not be used where the water pressure is insufficient to properly operate them. (See part 4715.1770, 
subpart 2.) When the valve is operated, it shall complete the cycle of operation automatically, opening ftiUy 
and closing positively under the water line pressure. Each flushometer shall be provided with a means for 
regulating the flow through it. Flushometer valves installed on any plumbing fixture or equipment whose 
water supply inlet or portion thereof can be submerged shall be provided with a vacuum breaker. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1350 GARBAGE CAN WASHERS. 

Garbage can washers shall be separately trapped and vented. The receptacle receiving the wash from 
the garbage cans shall be provided with a removable basket or strainer to prevent discharge of large particles 
into the building drainage system. Any water supply connection shall be protected against backflow by an 
air gap or a vacuum breaker. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1360 LAUNDRY TRAYS. 

Each compartment of a laundry tray shall be provided with a waste outlet not less than 1-1/2 inches in 
diameter. A strainer or crossbar shall be provided to restrict the clear opening of the waste outlet. The water 
supply faucet shall have a plain end spout or, if threaded, shall be equipped with a vacuum breaker. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715. 1380 PLUMBING CODE 58 



4715.1370 LAVATORIES. 

Lavatories shall have waste outlets not less than 1-1/4 inches in diameter. A strainer, pop-up stopper, 
crossbars, or similar device shall be provided. 

Water supply to public lavatories shall not be spring closing unless they are of the delayed action type. 

Each 18-inch unit of usable length of a straight-line or circumference of a circular multiple use 
lavatory shall be considered equivalent to one lavatory as it affects the fixture usage requirements; provided 
hot and cold or tempered water suitable for hand washing is available for each 18-inch interval. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1380 SHOWERS. 

Subpart 1. Water supply riser. Every water supply riser from the shower valve to the shower head 
outlet, whether exposed or not, shall be securely attached to the structure. 

Subp. 2. Shower waste outlet. Waste outlets, other than those in bathtubs, serving a single shower 
shall be at least 1-1/2 inches in diameter and have removable strainers not less than three inches in diameter 
having strainer openings not less than one-fourth inch in minimum dimension. Waste outlets shall be 
securely fastened to the waste pipe making a watertight connection thereto. Waste outlets serving showers, 
except single-head showers, must be at least two inches in diameter and must have removable strainers 
not less than three inches in diameter. Where each shower space is not provided with an individual waste 
outlet, the waste outlet must be located and the floor pitched so that the water from one shower does not 
flow over the floor area serving another shower. 

Subp. 3. Shower floors or receptors. Floors or receptors under shower compartments shall be laid 
on or be supported by a smooth and structurally sound base. Floors under shower compartments, other than 
those laid directly on the ground surface or where prefabricated receptors have been provided, shall be lined 
and made watertight by the provision of suitable shower pans of durable material. Such pans shall turn up 
on all sides at least two inches above the finished threshold level. Pans shall be securely fastened to the 
waste outlet at the seepage entrance making a watertight joint between the pan and the outlet. Finished fioor 
surfaces shall be constructed of smooth, noncorrosive, nonabsorbent, and waterproofed materials. 

Subp. 4. Shower compartments. No shower stall or receptor shall have a finished interior dimension 
which is less than 30 inches, and each shower compartment shall be of a finished size capable of completely 
encompassing a 30-inch circle measured at the height of the shower control handles, when the door or curtain 
is closed, andof a horizontal cross sectional area ofnot less than 900 square inches. The 30-inch requirement 
shall not apply to a bathtub used as a shower or to showers installed in remodeling. 

Subp. 5. Anti-scald devices. A shower or combination shower-bath in a new or remodeled 
installation must be equipped with an anti-scald type shower control valve. The valve must be of the 
thermostatic or pressure -balancing type in accordance with ANSI/ASSE Standard 1016-96. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



59 PLUMBING CODE 4715.1420 

The temperature of mixed water to multiple showers must be controlled by a master anti-scald 

type thermostatic blender, or the showers must be individually equipped with approved anti-scald type 

shower control valves. 

Statutory Authority: MS s 16B.59; 16B.61; 16B.62; 16B.64; 326.37 to 326.45 
History: 15 SR 76; 19 SR 590; 28 SR 146 
Posted: July 31, 2007 

4715.1390 SINKS. 

Subpart 1. Drain sizing. Sinks shall be provided with waste outlets not less than 1-1/2 inches in 
diameter. A strainer, crossbar, or similar device shall be provided. Sinks on which a food grinder is installed 
shall have a waste opening of not less than 3-1/2 inches in diameter. Pot or scullery sinks must be provided 
with waste outlets not less than two inches in diameter. 

Subp. 2. Commercial kitchen sinks. All pot, scullery, food preparation, and bar sinks must be 
connected directly to the drainage system. A floor drain constructed without a backwater valve must be 
installed on the individual branch serving the fixture to be protected. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686; 28 SR 146 

Posted: July 31, 2007 

4715.1400 SPECIAL PLUMBING FIXTURES. 

Baptisteries, ornamental and lily pools, aquariums, ornamental fountain basins, swimming pools, and 
similar constructions when provided with water supplies shall be protected from back-siphonage as required 
in parts 4715.2000 to 4715.2170. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1410 URINALS. 

Floor-type trough urinals are prohibited. 
Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

4715.1420 WATER CLOSETS. 

Subpart 1 . Prohibited water closets. Pan, valve, plunger, offset, latrine, and frostproof water closets 
are prohibited. Water closets which have an invisible seal, an unventilated space, or walls that are not 
thoroughly washed at each discharge, are prohibited. Any water closet which might permit siphonage of the 
contents of the bowl back into the flush tank is prohibited. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715. 1430 PLUMBING CODE 60 



Subp. 2. Water closet bowls. All water closet bowls must be of the elongated type, except that 
regular type round bowls may be used in residential or dwelling type occupancy. 

Subp. 3. Water closet seats. Water closets must be equipped with seats of smooth nonabsorbent 
material. All seats of water closets of elongated type provided for public use must be of the open-front type. 
Integral water closet seats must be of the same material as the fixture. The top of the seat must not be over 
two inches above the rim of the fixture; seat lifts may not be used. 

Statutory Authority: MS s 16B.59 to 16B. 73; 326.37 to 326.45 

History: 11 SR 1405 

Posted: July 31, 2007 

HANGERS AND SUPPORTS AND PROTECTION 

4715.1430 HANGERS AND SUPPORTS. 

Subpart 1. Material. Hangers, anchors, and supports shall be made of metal or other material of 
sufficient strength to support the piping and its contents. Piers may be concrete, brick, or other approved 
material. 

Subp. 2. Attachment to building. Hangers and anchors shall be securely attached to the building 
construction at sufficiently close intervals to support the piping and its contents. 

Subp. 3. Vertical piping. Vertical piping shall be secured at sufficiently close intervals to keep the 
pipe in alignment. Vertical piping of the following materials shall be supported at not more than the distance 
intervals shown: 

A. Cast-iron soil pipe, at base and at each story height. Neoprene jointed pipe at five foot 
intervals, except where ten foot lengths are used. 

B. Threaded pipe (SPS), every other story height. 

C. Copper tubing, at each story. 

D. Lead pipe, four foot intervals. 

E. Plastic pipe, 1-1/4 inch and 1-1/2 inch sizes, exposed pipe at four foot intervals, concealed 
pipe same as item F (two inches and over). 

F. Plastic pipe, two inch and over, at each story. 

Subp. 4. Horizontal piping. Horizontal piping shall be supported at sufficiently close intervals to 
keep it in alignment and prevent sagging: 

A. Cast-iron soil pipe, five foot intervals except where ten foot lengths of cast-iron soil pipe 
are used, ten foot intervals between supports are acceptable. 

B. Threaded pipe, 12 foot intervals. 

C. Copper tubing (1-1/4 inch or less), six foot intervals. 

D. Copper tubing (1-1/2 inch or over), ten foot intervals. 

E. Lead pipe, on continuous metal or wood strips for its entire length. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



61 PLUMBING CODE 4715.1510 



F. Plastic pipe, 32-inch intervals except where conveying waste from dishwashers or similar 
hot water wastes it shall be supported on continuous metal or wood strips for its entire length. 

Subp. 5. Closet bends. Joined to a stack by means of neoprene gasketed or solvent welded joints 
shall be adequately supported both vertically and horizontally to prevent movement in any direction. 

Subp. 6. Base of stacks. Stacks shall be adequately supported at their bases. 

Subp. 7. Piping in the ground. Piping in the ground shall be laid on a firm bed for its entire length, 
except where support is otherwise provided which is adequate in the judgment of the administrative authority. 
Installation of plastic sewer pipe must comply with ASTM D2321. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686 

Posted: July 31, 2007 

4715.1440 PROTECTION OF PLASTIC PIPE. 

All plastic and copper pipe and tubing passing through studs or plates that are within one and one-fourth 
inches of the outside of the stud or plate must be protected by the provision of 1/16 inch or 0.060 mild steel 
plates attached to the outside of the stud or plate, or equivalent protection. 

Statutory Authority: MSs 16B.61; 16B.62; 326.37 

History: 75 SR 76; 19 SR 590 

Posted: July 31, 2007 

INDIRECT WASTE PIPING 

4715.1500 INDIRECT WASTE CONNECTIONS. 

No cold storage room, refrigerator, cooling counter, compartment, receptacle, appurtenance, or device, 
which is used, designed, or intended to be used for the storage or holding of food or drink, shall have any 
drain pipe in connection therewith directly connected to any soil, waste, or vent pipe. Such equipment shall 
be discharged to the drainage system through an airbreak as defined in part 4715.1580. 

The foregoing does not apply to a dishwashing or culinary sink in a food preparation room. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1510 INDIRECT WASTE PIPING. 

Indirect waste piping must be installed so as to permit ready access for flushing and cleaning, and must 
meet the material requirements of the code. Except as otherwise herein provided, the size and construction 
of indirect waste piping must be in accordance with parts 4715.2300 to 4715.2660, regulating the installation 
of waste and vent piping. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.1550 PLUMBING CODE 62 

Indirect waste pipes from appliances, devices, or other equipment not regularly classed as plumbing 
fixtures, but which are equipped with drainage outlets, must be trapped, but the traps need not be vented 
and the waste pipe must be a minimum of three-fourths inch size, but not less than the size of the outlet 
or tail piece of the fixture, appliance, or equipment served. However, overflow pans and drip outlets need 
not be trapped and may be the same size as the outlet. Alternate materials may be accepted for drains from 
overflow pans and drip outlets if proper pitch, alignment, and support are maintained. 

Statutory Authority: MS s 16B.59 to 16B. 73; 326.37 to 326.45 

History: 11 SR 1405; 19 SR 590 

Posted: July 31, 2007 

4715.1520 CONNECTIONS FROM WATER DISTRIBUTION SYSTEM. 

Indirect waste connections shall be provided for drains, overflows, or relief vents from the water 
distribution system by means of an air gap. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1530 STERILIZERS. 

Appliances, devices, equipment, or other apparatus such as stills, sterilizers, and similar equipment 
requiring water and waste shall be indirectly connected, or provided with an air gap between the trap and 
the appliance. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1540 POTABLE CLEAR WATER WASTES. 

Expansion tanks, cooling jackets, sprinkler systems, or any similar devices which are directly 
connected to the potable water system and which waste clear water only shall be discharged to the drainage 
system through an air gap. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1550 DRINKING FOUNTAINS. 

Drinking fountains may be installed with indirect wastes. 
Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



63 PLUMBING CODE 4715.1590 

4715.1560 SWIMMING POOLS. 

Piping carrying waste water from swimming pools or wading pools, including pool drainage, backwash 
from filters, water from scum gutter drains, or floor drains which serve walks around pools, shall be installed 
as an indirect waste. Pumps may be utilized to lift waste water when the indirect waste line is below the 
sewer grade. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1570 METHOD OF PROVIDING AN AIR GAP. 

The air gap between the indirect waste pipe and the building drainage system must be at least twice 
the effective diameter of the drain served and must be provided by one of the following methods: 

A. To a receptor. Extend an indirect waste pipe to an open, accessible, individual waste sink, 
floor drain, or other suitable fixture which is properly trapped and vented. 

The indirect waste pipe must terminate a sufficient distance above the flood level rim of the 

receiving fixture to provide the required air gap. 

B. To the inlet side of a trap. Provide an air gap in the drain ahead of the connection to the 
inlet side of the trap, which receives the waste from the indirect waste. 

Statutory Authority: MS s 16B.59 to 16B. 73; 326.37 to 326.45 

History: 11 SR 1405 

Posted: July 31, 2007 

4715.1580 METHOD OF PROVIDING AN AIR BREAK. 

The air break shall be so installed as to prevent back flow into the fixture, appliance, or device by one 
of the following methods : 

A. Discharging to the inlet side of the trap of a floor drain, sink, or receptor whose flood level 

rim is below the bottom of the fixture to be protected. 

B. Discharging at or below the spill rim of a floor drain, sink, or receptor whose flood level 
rim is below the bottom of the fixture to be protected. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1590 RECEPTORS OR SUMPS. 



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4715.1610 PLUMBING CODE 64 



Subpart 1. Installment. Waste receptors or sumps receiving the indirect waste shall not be installed 
in any toilet room, nor in inaccessible or unventilated space, such as a closet or storeroom. 

Subp. 2. Cleanout location. Ifthe indirect waste receptor is set below floor level, it shall be equipped 
with a running trap adjacent thereto, with the trap cleanout brought up to floor level. All plumbing receptors 
receiving the discharge of the indirect waste pipes, shall be of such shape and capacity as to prevent splashing 
or flooding. 

Subp. 3. Domestic or culinary fixtures prohibited as receptors. No plumbing fixture which is 
used for domestic or culinary purposes shall be used to receive the discharge of an indirect waste. Domestic 
dishwashers may discharge into a sink, sink tail-piece, or food-waste grinder. 

Subp. 4. Stand pipe receptors. The stand pipe receptor for an automatic clothes washer shall be 
trapped and vented, except that multiple clothes washers in the same room may be discharged to multiple 
standpipes that are manifolded together and use a single trap. The stand pipe shall extend not more than 30 
inches, nor less than 1 8 inches above its trap, and the trap shall be installed at least six inches above the floor. 

Subp. 5. [Repealed, 19 SR 590] 

Statutory Authority: MS s 16B.61; 16B.62; 326.37 to 326.45 

History: 75 SR 76; 19 SR 590 

Posted: July 31, 2007 

SPECIAL WASTES 

4715.1600 CHEMICAL WASTES. 

Chemical or industrial liquid wastes which are likely to damage or increase maintenance costs on the 
drainage system, shall be pretreated to render them innocuous prior to discharge into the drainage system, 
when required by the administrative authority. 

Piping conveying industrial, chemical, or process wastes from their point of origin to sewer connected 
pretreatment facilities shall be of such material and design as to adequately perform its intended function 
to the satisfaction of the administrative authority. Drainage discharge piping from pretreatment facilities or 
interceptors shall conform to standard drainage installation procedure. 

No chemical vent shall intersect or tie into any vent for other services, except where permitted by the 
administrative authority. 

The provision of this part relative to materials and construction for chemical piping need not apply 
to domestic photographic darkroom installations. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1610 STEAM AND HOT WATER WASTES. 

The end of the blowoff piping from any boiler or the vent pipe from any blowofiftank shall not terminate 
in any location where the discharge can endanger the safety of any person or property. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



65 PLUMBING CODE 4715.1710 



The exhaust, blowofif, or drain from a boiler or heat exchanger shall not connect directly with any 
part of the drainage system, but may connect indirectly. 

All such pipes from a high pressure steam source shall be indirectly connected by discharging into a 
blowoff tank or condenser as required by the state of Minnesota high pressure steam code. 

All such pipes from low-pressure steam boilers and hot water boilers rated at 150 horsepower or 
more shall discharge into a tank or condenser such that the discharge shall be effectively lowered below 180 
degrees Fahrenheit and the pressure reduced to atmospheric. 

In a similar manner, all other such pipes which would cause a discharge of steam or water to enter 
the sewer above 180 degrees Fahrenheit for a period of more than ten minutes shall be equipped with a 
means of lowering the entering temperature below 180 degrees Fahrenheit. This provision is not meant to 
be applied to boilers or heat exchangers which are drained on rare occasions. Drains from pressing machines 
and similar equipment may waste into an open floor drain. 

Any closed condenser or sump shall be provided with a relief vent not less than one pipe size larger 
than the largest inlet, which relief pipe or vent should be taken off the top, and extended separately full size 
through the roof. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

WATER SUPPLY AND DISTRIBUTION 

4715.1700 WATER REQUIRED. 

Every building equipped with plumbing fixtures and used for human occupancy or habitation shall 
be provided with a supply of potable water, which meets the standards of the Department of Health, in the 
amounts and at the pressures specified in this chapter. For permanent residences or buildings in which people 
are employed, hot water shall be provided to all plumbing fixtures requiring hot water for proper use. 

Only potable water shall be accessible to plumbing fixtures supplying water for drinking, bathing, 
culinary use, or the processing of food, medical, or pharmaceutical products. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1710 WATER SERVICE. 

Subpart 1. Size of water service. The water service pipe shall be of sufficient size to furnish water 
to the building in quantities and at the pressures required elsewhere in the code. It shall in no case be less 
than three-fourths inch nominal diameter. Methods for sizing the water service pipe are described in parts 
4715.3500 to 4715.3800. 

Subp. 2. Separation of water service and building sewer. Except as permitted in this subpart, the 
underground water service pipe and the building drain or building sewer shall not be less than ten feet apart 
horizontally and shall be separated by undisturbed or compacted earth. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715. 1730 PLUMBING CODE 66 

NOTE: See chapter 4725 relating to wells and borings regarding separation of buried sewers 
from wells. 

The water service pipe may be placed in the same trench with the building drain and the building 

sewer provided approval is given by the administrative authority and the following conditions are met: 

A. The bottom of the water service pipe, at all points, shall be at least 12 inches above the top 
of the sewer line at its highest point. 

B. The water service pipe shall be placed on a solid shelf excavated at one side of the common 
trench. The water service pipe shall preferably be of one piece. Where this is not feasible the number of 
joints in the service pipe shall be kept to a minimum. 

C. The sewer and water service pipes shall be tested prior to backfilling, as described in part 
4715.2820, or by methods acceptable to the administrative authority. 

D. Where the provisions of items A and B cannot be met, the sewer pipe shall be of cast iron 
or plastic 6A, 6B, 6C(2), or 6C(3) and the water pipe of copper, or cast iron, or plastic 6D, 6E, 6F, or 6G 
(part 4715.0420, subpart 3). 

E. Where the water service pipe must cross the building sewer, the bottom of the water service 
pipe located within ten feet of the point of crossing shall be at least 12 inches above the top of the sewer, 
except where this is not feasible, the sewer shall be of cast iron or plastic 6A, 6B, 6C(2), or 6C(3) {part 
4715.0420, subpart 3) for at least ten feet on either side of the crossing. 

Subp. 3. Water service near sources of pollution. Potable water service pipes must not be 
located in, under, or above cesspools, septic tanks, septic tank drainage fields, seepage pits, soil treatment 
systems, buried tanks containing chemicals or petroleum products, or any other source of pollution that 
in the judgment of the administrative authority might contaminate the potable water supply. A horizontal 
separation often feet must be maintained. 

Statutory Authority: MS s 16B.62; 326.37 to 326.45 

History: 9 SR 1557; 19 SR 590 

Posted: July 31, 2007 

4715.1720 DESIGN OF BUILDING WATER DISTRIBUTION SYSTEM. 

The design of the building hot and cold water distribution system shall conform to good engineering 
practice. Methods used to determine pipe sizes shall be acceptable to the administrative authority. (A guide 
to the design of building water supply systems is given in parts 4715.3500 to 4715.3800.) 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1730 SIZE OF FIXTURE BRANCH. 

Subpart 1. Requirement. The minimum size of the fixture branch pipe shall be as shown in subpart 
2. The branch pipe to any fixture shall terminate not more than 30 inches from the point of connection to 



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67 



PLUMBING CODE 4715.1740 



the fixture and in every instance shall be brought to the floor or wall adjacent to the fixture. No concealed 
water branch pipe shall be less than one-half inch in size. In single-family dwelling units, not more than 
three fixtures located in the same room may be supplied by a one-half inch size pipe. 

Subp. 2. Table of minimum sizes of fixture water branch lines. 



Type of fixture or device 



Nominal pipe 
size (inches) 



Bath tubs 

Combination sink and tray 

Cuspidor 

Drinking fountain 

Dishwasher (domestic) 

Kitchen sink (res.) 

Kitchen sink (com.) 

Lavatory 

Laundry tray 

Sinks (service, slop) 

Sinks flushing rim 

Urinal (flush tank) 

Urinal (direct flush valve) 

Water closet (tank type) 

Water closet (flush valve type) 

Hose bibs 

Wall hydrant 

Domestic clothes washer 

Shower (single head) 

Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 



1/2 

1/2 

1/2 

1/2 

1/2 

1/2 

3/4 

1/2 

1/2 

1/2 

3/4 

1/2 

3/4 

1/2 

1 

3/4 

3/4 

1/2 

1/2 



4715.1740 WATER PRESSURE. 

When street main pressure exceeds 80 psi, an approved pressure reducing valve shall be installed in the 
water service pipe near its entrance to the building to reduce water pressure to 80 psi or lower. Where street 
water main pressures fluctuate significantly, the building water distribution system shall be so designed for 
the minimum pressure available. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715. 1770 PLUMBING CODE 68 

Whenever water pressure from the street main or other source of supply is insufficient to provide 
flow pressure at fixture outlets as required under part 4715.1770, a booster pump and pressure tank or other 
approved means shall be installed on the building water supply system. See part 4715.1810, subpart 3 for 
installation. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1750 WATER HAMMER. 

In all building supply systems in which devices or appurtenances are installed which cause noises due 
to water hammer, protective devices or approved mechanical shock absorbers shall be installed as close 
as possible to the quick-acting valve causing the water hammer. Where mechanical devices are used the 
manufacturer's specifications shall be followed as to location and method of installation. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686 

Posted: July 31, 2007 

4715.1760 SUPPLY DEMAND. 

The supply demand in gallons per minute in the building water distribution system shall be determined 
on the basis of the load in terms of supply fixture units and of the relationship between load and supply 
demand. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1770 MINIMUM PRESSURES REQUIRED IN WATER DISTRIBUTION SYSTEM. 

Subpart 1. Requirement. Based on the minimum static water pressure available, pipe sizes shall be 
selected so that under conditions of peak demand a minimum flow pressure at the point of discharge shall 
not be less than shown in subpart 2. 

In determining minimum pressures at the outlets, allowance shall be made for the pressure drop 

due to friction loss. 

Subp. 2. Table of minimum flow pressure and flow rates. 



Flow Pressure Flow Rate 

Location psi gpm 

Ordinary basin faucet 8 2.0 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



69 PLUMBING CODE 4715.1800 

Self-closing basin faucet 8 2.0 

Sink faucet, 3/8 inch 8 2.0 

Sink faucet, 1/2 inch 8 2.0 

Bathtub faucet 8 6.0 

Laundry tub cock, 1/2 inch 8 5.0 

Shower 8 2.0 

Ball cock for closet 8 3.0 

Flush valve for closet 15 1 5-35 

Flushometer valve for urinal 15 1 5.0 

Drinking fountains 15 0.75 

Sill cock-wall hydrant 10 5.0 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 
History: 23 SR 686; 28 SR 146 
Posted: July 31, 2007 

INSTALLING THE BUILDING WATER DISTRIBUTION SYSTEM 

4715.1800 WATER SUPPLY CONTROL VALVES. 

Subpart 1. Stop and waste valves prohibited. Combination stop and waste valves or cocks should 
not be installed underground in water service piping. They may be installed only if approved by the 
administrative authority and when located at least two feet above the water table and at least ten feet from 
any sewer. 

Subp. 2. Underground stop valve. On each water service from a street main to a building an 
approved gate valve or ground key stopcock shall be installed. This valve or stopcock shall be provided 
with an approved valve box and shall not be under the driveway. However, if there is an accessible stop 
valve in the street, no other stop is necessary underground. 

Subp. 3. Building valve. Each building water service shall be provided with a gate valve or other 
full-way valve located inside the building near the point that the water service enters. 

Subp. 4. 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 supply. 

Subp. 5. Valves in dwelling units. In each single or multiple unit dwelling, each family unit shall 
be controlled by anarrangement of shutofif valves which will permit each group of fixtures or the individual 
fixtures to be shut off without interference with the water supply to any other family unit or portion of the 
building. 

Subp. 6. Valves in buildings other than dwellings. In all buildings other than dwellings, shutoff 
valves shall be installed, which permit the water supply to all equipment in each separate room or to each 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.1810 PLUMBING CODE 70 



individual fixture to be shut off without interference with the water supply to any other room or portion of 
the building. 

Subp. 7. Valves for sill cocks. All sill cocks and wall hydrants shall be separately controlled by a 
valve inside the building. 

Subp. 8. Tank controls. Supply lines to and from pressure or gravity tanks shall be valved at or near 
the tanks. 

Subp. 9. Water heating equipment valve. The cold water branch to each hot water storage tank or 
water heater shall be provided with a full way valve located near the equipment. Each tank or heater shall 
be equipped with an approved automatic relief valve as specified in parts 4715.2200 and 4715.2210. 

Subp. 10. Valves to be accessible. All water supply control valves shall be placed so as to be 
accessible. 

Subp. 11. Control valve design. Except to single fixtures, control valves on all water lines shall be 
full-way type and the same size as the line on which they are installed. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.1810 WATER PRESSURE BOOSTER SYSTEMS. 

Subpart 1. Water pressure booster systems required. When the water pressure in the public 
water main or individual water supply system is insufficient to supply the probable peak demand flow 
to all plumbing fixtures and other water needs freely and continuously with the minimum pressures and 
quantities specified in part 4715.1770, subpart 2 or elsewhere in this code and in accordance with good 
practice, the rate of supply shall be supplemented by an elevated water tank, a hydropneumatic pressure 
booster system, or a water pressure booster pump installed in accordance with subpart 5. 

Subp. 2. Support. All water supply tanks shall be adequately supported. 

Subp. 3. Covers. All water supply tanks shall be covered to keep out contaminants. 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 of not less than 16 mesh. 

Subp. 4. Overflows for water supply tanks. Each gravity or suction water supply tank shall be 
provided with an overflow having a diameter not less than shown in subpart 10. Sizes of overflow pipes 
for water supply tanks. The overflow outlet shall discharge above and within not less than six 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 16 mesh. 

Subp. 5. Water supply to booster pumps. When a booster pump is used on a water pressure booster 
system, it shall be supplied through a surge tank or if supplied through a direct connection, a low pressure 
cutoff switch (10 psi) and a vacuum relief valve or tank shall be installed on the suction side of the booster 
pump to prevent the creationof a vacuum or a negative pressure on the suction side of the pump. If installed 
below grade it shall be installed in a normally occupied area and on a pedestal at least 24 inches above the 
floor. 

Subp. 6. Potable water inlet to tanks. Potable water inlets to gravity, surge, or break tanks shall be 
controlled by a ball cock or other automatic supply valve so installed as to prevent the tank from overflowing. 



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71 



PLUMBING CODE 4715.1810 



The inlet shall be terminated so as to provide an accepted air gap but in no case less than four inches above 
the overflow. 

Subp. 7. Tank drain pipes. Each tank shall be provided at its lowest point with a valved pipe to 
permit emptying the tank, which shall discharge as required for overflow pipes, and not smaller in size than 
shown in subpart 1 1 . 

Subp. 8. Prohibited location of potable supply tanks. Potable water tanks shall not be located 
directly under any soil or waste piping. 

Subp. 9. Pumps and other appliances. Water pumps, filters, softeners, tanks, and all other devices 
and appliances used to handle or treat potable water shall be protected against contamination. 

Subp. 10. Sizes for overflow pipes for water supply tanks. 



Maximum Capacity of 
Water Supply Line to Tank 



Diameter of Overflow 
Pipe (Inches ID) 



- 50 gpm 
50-150 gpm 
100 - 200 gpm 
200 - 400 gpm 
400 - 700 gpm 
700 - 1000 gpm 
Over 1000 gpm 

Subp. 11. Size of drain pipes for water tanks. 



2 

2-1/2 

3 

4 

5 

6 

8 



Tank Capacity (gallons) 



Drain Pipe (inches) 



Up to 750 
751 to 1500 
1501 to 3000 
3001 to 5000 
5001 to 7500 
Over 7500 



1 

1-1/2 

2 

2-1/2 

3 

4 



Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.1911 PLUMBING CODE 72 



PROTECTION OF POTABLE WATER SUPPLY 

4715.1900 DESIGN, MAINTENANCE, AP^JD INSTALLATION. 

A potable water supply system shall be designed, installed, and maintained in such manner as to prevent 
contamination from nonpotable liquids, solids, or gases, from being introduced into the potable water supply 
through cross-connection or any other piping connections to the system. 

Statutory Authority: MS s 144.12; 326.37 to 326.45 

Posted: July 31, 2007 

4715.1910 IDENTIFICATION OF POTABLE AND NONPOTABLE WATER. 

Subpart 1. Identification methods. In all buildings where dual water distribution systems, one 
potable water and other nonpotable water, are installed, each system shall be identified, either by color 
marking or metal tags. 

Subp. 2. Color marlcing. When color marking is used, potable water lines should be painted 
green and nonpotable water lines should be painted yellow. This requirement may be met by painting 
three-inch- wide bands green or yellow at intervals of not more than 25 feet and at points where piping 
passes through walls, floors, or roofs in which case the bands shall be applied to the piping on both sides 
of the walls and both above and below the floor or roof. Points of outlets for nonpotable water shall be 
marked with a tag or color coded. 

Subp. 3. Metal tags. When tags are used, potable water lines shall be identified by 
three-inch-diameter metal tags bearing the legend "SAFE WATER" in letters not less than one-half inch 
in height. 

Nonpotable water lines shall be identified by firmly attached metal tags having the shape of a 
four-inch equilateral triangle bearing the legend "NONPOTABLE WATER" in letters not less than 7/16 
inch in height. 

As in the use of color bands, tags shall be attached to pipes at intervals of not more than 25 feet, 

and, at either side of points where pipes pass through walls and above and below points where pipes 

pass through floors or roofs. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 
History: 23 SR 686 
Posted: July 31, 2007 

4715.1911 TOXIC MATERMLS AND USED PIPE. 

Piping conveying potable water shall be constructed of nontoxic material. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



73 PLUMBING CODE 4715.1940 



No material or substances that could produce either toxic conditions, taste, odor, or discoloration in 
a potable water system shall be introduced into or used in such systems. 

The interior surface of a potable water tank shall not be lined, painted, or repaired with any material 
which will affect either the taste, odor, color, or potability of the water supply when the tank is placed in or 
returned to service. 

Piping which has been used for any other purpose then conveying potable water shall not be used for 
conveying potable water. 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 15 SR 76 

Posted: July 31, 2007 

4715.1912 USED WATER RETURN PROHIBITED. 

Water used for cooling of equipment or other processes shall not be returned to the potable water 
system. Such water shall be discharged into the drainage system through an air gapped indirect waste or 
other approved method of disposal. 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 15 SR 76 

Posted: July 31, 2007 

4715.1920 CROSS-CONNECTION CONTROL. 

Cross-connections between potable water systems and other systems or equipment containing water 
or other substances of unknown or questionable safety are prohibited, except when and where, as approved 
by the authority having jurisdiction, suitable protective devices such as break tanks, reduced pressure zone 
backflow preventer, or equal, are installed, tested, and maintained to ensure proper operation on a continuing 
basis. 

Cross-connections between an individual water supply and a potable public supply shall not be made 
unless specifically approved by the authority having jurisdiction. 

Statutory Authority: MS s 144.12; 326.37 to 326.45 

Posted: July 31, 2007 

4715.1930 [Renumbered 4715.1911] 
Posted: July 31, 2007 

4715.1940 POTABLE WATER CONNECTIONS TO HEATING OR COOLING SYSTEMS. 

Potable water connections to boiler feed water systems, cooling systems, or other liquid systems, in 
which water conditioning chemicals may be introduced shall be made through an air gap or provided with 
an approved backflow preventer located in the potable water line before the point where such chemicals may 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715. 1950 PLUMBING CODE 74 



be introduced. Where a system is filled with an antifreeze or toxic solution a permanent tag will be placed 
in plain view stating "Caution, this system contains antifreeze/toxic solution." 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 9 SR 1557; 15 SR 76 

Posted: July 31, 2007 

4715.1941 HEAT EXCHANGERS. 

Subpart 1. Construction requirement. Devices utilizing any heat transfer medium to exchange 
thermal energy with potable water must be constructed so that a single failure of any wall in the system will 
not cause a cross-connection with or permit back siphonage of heat transfer medium into the potable water 
system. 

Subp. 2. Double-wall heat exchanger. A double-wall heat exchanger must be designed in a way 
that any failure of a wall must allow the discharge to the atmosphere of the heat transfer medium or the 
potable water contained by the wall. The discharge location must be visible to the operator or owner of the 
system and be located so that no hazards are created by the discharge. 

Subp. 3. Single-wall heat exchanger. A single-wall heat exchanger may be used if it satisfies all of 
the following conditions: 

A. The heat transfer medium contains only substances which are recognized as safe or approved 
by the United States Food and Drug Administration for food contact as listed in Code of Federal Regulations, 
title 21, part 182 of the Food Additive Regulations. 

B. Except where steam is used as the heat transfer medium, the pressure of the heat transfer 
medium must be less than the normal minimum operating pressure of the potable water system, and the 
system must be fitted with devices arranged to function automatically to maintain the pressure of the heat 
transfer medium entering the exchanger at a level below that of the potable water leaving the exchanger. 

C. The equipment is permanently labeled to specify all constituents of the heat transfer medium, 
to indicate that only additives recognized as safe by the United States Food and Drug Administration may 
be used, and to show the hazards and reasons for not using another type of medium. 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 9 SR 1557; 15 SR 76 

Posted: July 31, 2007 

4715.1950 PROHIBITED CONNECTIONS TO FIXTURES AND EQUIPMENT. 

Connections to the potable water supply system for the following shall be protected against backflow: 

A. bidets; 

B. operating, dissection, embalming, and mortuary tables or similar equipment; in such 
installation the hose used for water supply shall be equipped with a vacuum breaker installed at least six 
feet, six inches above the floor; 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



75 PLUMBING CODE 4715.2000 

C. pumps for nonpotable water, chemicals, or other substances; priming connections may be 
made only through an air gap; 

D. building drainage, sewer, or vent systems; and 

E. any other fixture of similar hazard. 
Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

4715.1960 REFRIGERATING UNIT CONDENSERS AND COOLING JACKETS. 

Except where potable water provided for a refrigerator condenser or cooling jacket is entirely outside 
the piping or tank containing a toxic refrigerant, with two separate thicknesses of metal separating the 
refrigerant from the potable water supply, inlet connection shall be provided with an approved backflow 
preventer. Also, adjacent to and at the outlet side of the backflow preventer, an approved pressure relief 
valve set to relieve at 5 psi above the maximum water pressure at the point of installation shall be provided 
if the refrigeration units contain more than 20 pounds of refrigerants. 

Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326.37 to 326.45 

History: 28 SR 146 

Posted: July 31, 2007 

4715.1970 [Renumbered 4715.1912] 

Posted: July 31, 2007 

PROTECTION OF POTABLE WATER AGAINST 
BACKFLOW AND BACK-SIPHONAGE 

4715.2000 WATER OUTLETS. 

A potable water system shall be protected against backflow and back-siphonage by providing and 
maintaining at each outlet: 

A. an air gap as specified herein between tiie potable water outlet and the flood level rim of the 

fixture it supplies or between the outlet and any other source of contamination; or 

B. a backflow preventer device or assembly to prevent the drawing of contamination into the 
potable water system. 

Statutory Authority: MS s 16B.62; 326.37 to 326.45 

History: 19 SR 590 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2010 PLUMBING CODE 



76 



4715.2010 MINIMUM REQUIRED AIR GAP. 

Subpart 1. Measurement. The minimum required 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 receptacle into which it discharges. 

Subp. 2. Requirement. The minimum required air gap shall be twice the effective opening of a 
potable water outlet unless the outlet is a distance less than three times the effective opening away from a 
wall or similar vertical surface in which cases the minimum required air gap shall be three times the effective 
opening of the outlet. In no case shall the minimum required air gap be less than shown in subpart 4. 

Subp. 3. Effect of walls, ribs, and similar obstructions. Side walls, ribs, or similar obstructions 
do not affect air gaps when spaced from inside edge of 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 for two intersecting walls. 

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 spout opening than specified in this subpart. 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. 
Subp. 4. Minimum air gaps for plumbing fixtures. 



Fixture 



Minimum Air Gap 

When Not Affected By When Affected By 
Near Wall (1) (Inches) Near Wall (2) (Inches) 



Lavatories and other fixtures with effective opening 
not greater than 1/2 inch diameter 



1.0 



1.50 



Sink, Laundry trays, goosenecli bath faucets and 
other fixtures with effective openings not greater than 
3/4 inch diameter 1.5 



2.25 



Over rim bath fillers and other fixtures with effective 
openings not greater than 1 inch diameter 2.0 



3.0 



Drinking water fountains 



1.0 



1.50 



Effective openings greater than one inch 



2x diameter of 
effective opening 



3x diameter of 
effective opening 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



77 PLUMBING CODE 4715.2100 

Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

4715.2020 DEVICES OR ASSEMBLIES FOR THE PROTECTION OF THE POTABLE WATER 
SUPPLY. 

Approved devices or assemblies to protect against backflow and back-siphonage must be installed at 
any plumbing fixture or equipment where backflow or back-siphonage may occur and where a minimum air 
gap cannot be provided between the water outlet to the fixture or equipment and its flood level rim. 

Statutory Authority: MS s 16B.61; 16B.62; 326.37 to 326.45 

History: 75 SR 76; 19 SR 590 

Posted: July 31, 2007 

4715.2030 APPROVAL OF DEVICES OR ASSEMBLIES. 

Before any device or assembly for the prevention of backflow or back-siphonage is installed, it shall 
have first been certified by a recognized testing laboratory acceptable to the administrative authority. Devices 
or assemblies installed in a building potable water supply distribution system for protection against backflow 
shall be maintained in good working condition by the person or persons responsible for the maintenance of 
the system. 

Statutory Authority: MS s 16B.62; 326.37 to 326.45 

History: 19 SR 590 

Posted: July 31, 2007 

INSTALLATION OF DEVICES 
4715.2100 BACKFLOW PREVENTERS. 

A. Atmospheric vacuum breaker (AVE): 

(1) must be installed at least six inches above spill line (see special requirements in part 
4715.2150); 

(2) no possibility of back pressure permitted; 

(3) only permitted on discharge side of last control valve; and 

(4) no more than eight hours of continuous line pressure permitted. 
B. Pressure vacuum breaker assembly (PYB): 

(1) must be installed at least 12 inches above spill line; 

(2) no possibility of back pressure permitted; and 

(3) continuous line pressure permitted. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2110 PLUMBING CODE 78 

C. Spill-proof vacuum breaker (SVB): 

(1) must be installed at least six inches above spill line; 

(2) no possibility of back pressure permitted; 

(3) continuous line pressure permitted; and 

(4) field testable. 

D. Hose connection vacuum breaker (Hose VB): 

(1) required for threaded hose connections; 

(2) back pressure not permitted; 

(3) continuous line pressure not permitted; and 

(4) any new device must be field testable. Exception: a vacuum breaker installed as an 
integral part of a product, approved to a standard, and installed at the factory will not be required to be field 
testable. 

E. Double-check valve with intermediate atmospheric vent (DCVIAV): 

(1) permitted for low hazard with small pipe sizes; 

(2) back pressure permitted; and 

(3) continuous line pressure permitted. 

F. Reduced pressure zone backflow preventer assembly (RPZ): 

(1) any degree of hazard permitted; 

(2) back pressure permitted; and 

(3) continuous line pressure permitted. 

G. Double-check valve assembly (DCVA): 

(1) permitted only for nontoxic, low hazard installations with nuisance or aesthetic 
concern; 

(2) back pressure permitted; and 

(3) continuous line pressure permitted. 
Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 
History: 15 SR 76; 19 SR 590; 23 SR 686; 28 SR 146 
Posted: July 31, 2007 

4715.2110 TYPES OF DEVICES REQUIRED WHERE AN AIR GAP CANNOT BE PROVIDED.* 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



79 



PLUMBING CODE 4715.2110 



A. Boiler, other than one- or two-family residential 

B. Boiler, one- or two-family residential 

C. Car wash 

D. Carbonated beverage machine (postmix) (see part 
4715.2163) 

E. Chemical line 
E. Chemical tank 
G. Chiller 

H. Cooling tower 

I. Dental units (separate assembly required for each 

unit) 

J. Dishwasher, commercial 

K. Fire sprinkler system^ 

L. Flush tank (water closet, urinal, similar) (see part 

4715.2150) 

M. Flush valve (water closet, luinal, similar) (see part 
4715.2150) 

N. Food and beverage equipment or system 

O. Garbage can washer 

P. Glycol or other antifreeze system 

Q. Lab equipment 

R. Lab faucet 

S. Laundry machine, commercial 

T. Lawn, garden or greenhouse sprinkler system 

U. Operating, dissection, embalming or mortuary 

table (see part 4715.1950) 

V. Private potable water supply (where permitted by 

administrative authority) 

W. Private nonpotable water supply (where permitted 
by administrative authority) 







Only 


allowed 






where 


no back 






pressiffe is possible 






SVB 






DCV 


or 


Hose 


RPZ 


lAV 


DCVA PVB 


AVB VB 


X 








X 


X 






X 




X 


X 



X 
X 
X 
X 

X 

X 

X 

X 
X 
X 
X 
X 

X 

X 

X 
X 
X 



X 



X 



X 



X 



X 



X 



X 



X 



X 



X 



X 



X 



X 



X 



X X 



X 



X 



X 


X 


X 


X 


X 


X 


X 


X 




X 


X 


X 


X 


X 



X 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2120 PLUMBING CODE 80 

X. Process line X X 

Y. Process tank X XX 

Z. RV dump station XX XX 

AA. Sewage treatment X XX 

BB. Soap dispenser XX XX 

CC. Swimming pool, fountain, pond, baptistry, 

aquarium or similar XX XX 

DD. Threaded hose connections, including: hose bibbs, 

hydrants, service sinks, laundry trays X X 

EE. Truck fill X XX 

FF. Vacuum systems or aspirators X XX 

1. For installations not listed in this part, review with the Administrative Authority. 

2. Installations must comply with AWWA-M14, chapter 6 (1990) except that the following statement is 
deleted from section 6.3: At any time where the fire sprinkler piping is not an acceptable potable water 
system material, there shall be a backflow-prevention assembly isolating the fire sprinkler system from the 
potable water system. 

3. A vacuum breaker installed as an integral part of a product approved to a standard does not require 
additional backflow prevention on the hose threads; the product must be constructed so that if the integral 
backflow preventer is removed, the remaining threads will not be hose thread type. An unprotected threaded 
hose connection must be protected against backflow by addition of a backflow preventer complying with 
ASSE 1052. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 15 SR 76; 19 SR 590; 23 SR 686; 28 SR 146 

Posted: July 31, 2007 

4715.2120 LOCATION OF BACKFLOW PREVENTERS. 

Backflow and back-siphonage preventing devices or assemblies must be located so as to be readily 
accessible, preferably in the same room with the fixture they serve. Installation in utility or service spaces, 
provided they are readily accessible, is also permitted. 

The access area must provide enough space for testing and maintenance of the device. A backflow 
preventer must not be installed in a pit or other confined area subject to recurrent flooding. When a conductor 
pipe is provided from a backflow preventer drain, a visible air gap must be provided at the device. New 
installations of reduced pressure zone backflow preventers must be at least 12 inches, but not more than six 
feet, above the finished floor or ground level. 

Statutory Authority: MS s 16B.59; 16B.61; 16B.62; 16B.64; 326.37 to 326.45 

History: 15 SR 76; 19 SR 590; 28 SR 146 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



81 



PLUMBING CODE 4715.2150 



4715.2130 [Repealed, 15 SR 76] 
Posted: July 31, 2007 

4715.2140 [Repealed, 15 SR 76] 
Posted: July 31, 2007 

4715.2150 CONNECTIONS NOT SUBJECT TO BACK PRESSURE. 

Subpart 1. Requirements. Where a water connection is not subject to back pressure an atmospheric 
type vacuum breaker shall be installed on the discharge side of the last valve on the line serving the fixture 
or equipment. Where a valve is installed on the discharge side of a vacuum breaker, that vacuum breaker 
must be a pressure-type vacuum breaker assembly which complies with part 4715.2030. A list of some 
conditions requiring protective devices of this kind is given in subpart 2. 

Subp. 2. Cross-connections where protective devices are required and critical level (C-L) 
settings for backflow preventers. Critical level (C-L) is defined as the level to which the backflow 
preventer (vacuum breaker) may be submerged before backflow will occur. Where the C-L is not shown 
on the preventer, the bottom of the device shall be taken as the C-L. 



Fixture or Equipment 



Method of Installation 



Aspirators and Ejectors 
Dental units 

Dishwashing machines 

Flushometer (Closet & Urinal) 
Garbage can cleaning machine 

Hose outlets 
Laundry machines 

Lawn sprinklers 

Steam tables 
Tank and vats 
Trough urinals 



C-L at least 6 inches above flood level of receptacle. 

On models without built-in vacuum breakers C-L at least 6 
inches above flood level rim of bowl. 

C-L at least 6 inches above flood level of machine. Install 
on both hot and cold water supply lines. 

C-L at least 6 inches above top of fixture supplied. 

C-L at least 6 inches above flood level of machine. Install 
on both hot and cold water supply lines. 

C-L at least 6 inches above highest point on hose line. 

C-L at least 6 inches above flood level of machine. Install 
on both hot and cold water supply lines. 

C-L at least 12 inches above highest sprinkler or discharge 
outlet. 

C-L at least 6 inches above flood level. 

C-L at least 6 inches above flood level rim or line. 

C-L at least 30 inches above perforated flush pipe. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2161 PLUMBING CODE 82 



Flush tanks Equip with approved ball cock. Where ball cocks touch 

tank water equip with vacuum breaker with C-L at least 
1 inch above overflow outlets. Where ball cock does 
not touch tank water, install ball cock outlet at least 1 
inch above overflow outlet or provide vacuum breaker as 
specified above. 

Hose bibbs (Where aspirators or ejectors C-L at least 6 inches above flood level of receptacle served, 
could be connected) 

Statutory Authority: MS s 16B.62; 326.37 to 326.45 
History: 19 SR 590 
Posted: July 31, 2007 

4715.2160 CONNECTIONS SUBJECT TO BACKPRESSURE. 

Where a potable water connection is made to a line, fixture, tank, vat, pump, or other equipment with 
a hazard of backflow or back-siphonage, where the water connection is subject to back pressure, and an air 
gap cannot be installed, the administrative authority may require the use of break tank and booster pump 
or, where conditions permit, an approved reduced pressure zone backflow preventer. A partial list of such 
connections is as follows: chemical lines, dock water outlets, individual water supplies, industrial process 
water lines, pressure tanks, pumps, steam lines, and tanks and vats-bottom inlets. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2161 INSTALLATION OF REDUCED PRESSURE BACKFLOW PREVENTERS. 

Subpart 1. Notification of installation. The administrative authority must be notified before 
installation of a reduced pressure backflow preventer assembly. 

Subp. 2. Testing and maintenance. The installation of reduced pressure backflow preventers shall 
be permitted only when a periodic testing and inspection program conducted by qualified personnel will 
be provided by an agency acceptable to the administrative authority. Inspection intervals shall not exceed 
one year, and overhaul intervals shall not exceed five years. The administrative authority may require more 
frequent testing if deemed necessary to assure protection of the potable water. Backflow preventers shall be 
inspected frequently after initial installation to assure that they have been properly installed and that debris 
resulting from the piping installation has not interfered with the functioning of the assembly. 

Subp. 3. Inspection and records. A test and inspection tag must be affixed to the device. The tester 
shall date and sign the tag and include the tester's backflow preventer tester identification number. Written 
records of testing and maintenance must be maintained and submitted to the administrative authority. 

Statutory Authority: MS s 16B.61; 16B.62; 326.37 to 326.45 

History: 75 SR 76; 19 SR 590 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



83 PLUMBING CODE 4715.2170 



4715.2162 DOUBLE CHECK - DOUBLE GATE VALVE ASSEMBLIES. 

The administrative authority may authorize the installation of approved, double check - double gate 
valve assemblies with test cocks as protective devices against back flow in connections between a potable 
water system and other nontoxic fluid systems which present no significant health hazards. 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 15 SR 76 

Posted: July 31, 2007 

4715.2163 CARBONATED BEVERAGE MACHINES. 

Postmix type carbonated beverage machines must have an approved double-check valve with an 
intermediate atmospheric vent type backflow preventer in the water line preceding the carbonator. The 
backflow preventer must be installed in accordance with ASSE Standard 1022. There must be no copper 
tubing in the system down line of the backflow preventer. 

Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326.37 to 326.45 

History: 75 SR 76; 28 SR 146 

Posted: July 31, 2007 

4715.2165 CHEMICAL/SOAP DISPENSING SYSTEMS. 

The installation of backflow preventers for chemical/soap dispensing systems must comply with ASSE 
Standard 1055. 

Exception: An atmospheric vacuum breaker integrally mounted on a faucet that is connected to a 
chemical/soap dispenser must be protected against back pressure by the installation of a pressure 
bleeding device and a backflow preventer complying with ASSE Standard 1052. The backflow 
preventer must be installed on the side outlet of the pressure bleeding device. No wye connector that 
has an integral shutoff may be connected to a faucet that has an integral atmospheric vacuum breaker. 

Statutory Authority: MSs 16B.59; 16B.61; 16B.64; 326.37; 326.40 

History: 28 SR 146 

Posted: July 31, 2007 

4715.2170 BAROMETRIC LOOP. 

Water connections where an actual or potential backflow or back-siphonage hazard exists may in lieu 
of devices specified in parts 4715.2140 to 471 5.2160 be provided with a barometric loop. Barometric loops 
shall precede the point of connection. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2210 PLUMBING CODE 84 



4715.2180 HOT WATER SUPPLY SYSTEM. 

Hot water shall be supplied to all plumbing fixtures and equipment used for bathing, washing, culinary 
purpose, cleansing, laundry, or building maintenance, where necessary for proper functioning. Hot water 
supply systems in four-story buildings or buildings where the developed length of hot water piping from the 
source of hot water supply to the farthest fixture supplied exceeds 100 feet should be of the return circulation 
type, to conserve water. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2190 COMBINATION WATER AND SPACE HEATING EQUIPMENT. 

Equipment used for heating domestic or service hot water and for space heating must be installed with 
a mixing valve to permit the user to control the temperature of the domestic or service hot water regardless 
of the space heating demand. 

The installation must include a drainage port and isolation valve to permit the user to purge the 
heating coils to waste after the nonheating season, or the system must be designed to automatically prevent 
stagnation. 

The water heater must be specifically designated by the manufacturer for use as a combination hot 
water and space heater. 

All pipes, joints, and appurtenances in the system must be of a type approved for potable water 
distribution. This provision is not intended to address the wall thickness of heating coils, which must be the 
responsibility of the manufacturer. 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 75 SR 76 

Posted: July 31, 2007 

4715.2200 PRESSlTiE RELIEF VALVES AND TEMPERATURE RELIEF VALVES DEVICES 
REQUIRED. 

Equipment used for heating water or storing hot water shall be protected by approved safety devices in 
accordance with one of the following methods: a separate pressure relief valve and a separate temperature 
relief valve; or a combination pressure and temperature relief valve. All safety devices shall meet the 
current requirements of the A.N. 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 must have certification by an approved laboratory 
as having met these requirements. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2210 PRESSlTiE RELIEF VALVES. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



85 PLUMBING CODE 4715.2220 



Subpart 1. Installation. Pressure relief valves shall have arelief rating adequate to meet the pressure 
conditions in the equipment served. They shall be installed in the cold water supply line to the heating 
equipment served except where scale formation from hard water may be encountered in which case they 
may be installed in the hot water supply line from the heating equipment served. There shall be no shutoff 
valve between the pressure relief valve and the tank. The setting shall not exceed the tank working pressure. 

Subp. 2. Temperature relief valves. Temperature relief valves shall be of adequate relief rating, 
expressed in Btu/hr, for the equipment served. They shall be installed so that the temperature sensing element 
is immersed in the hottest water in the head or within the top six inches of the vertical portion of the tank. 
The valve shall be set to open when the stored water temperature is 210 degrees Fahrenheit (or less). 

Subp. 3. Combination pressure-temperature relief valves. Combination pressure temperature 
relief valves may be used for storage equipment provided the other applicable requirements for individual 
pressure and individual temperature relief valves are met. 

Subp. 4. Installation of relief valves. No check valve or shutoff valve shall be installed between 
any safety device and the hot water equipment used, nor shall there be any shutoff valve in the discharge 
pipe from the relief valve. The discharge pipe shall be full size and run to within 18 inches of the floor or a 
safe place of disposal. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686 

Posted: July 31, 2007 

4715.2215 THERMAL EXPANSION CONTROL. 

A device for controlling thermal expansion shall be installed on the water distribution system when 
thermal expansion within the system, in combination with a check valve or backflow preventer, causes the 
water pressure to exceed the pressure setting of the pressure relief valve on the water heater. 

Statutory Authority: MS s 16B.62; 326.37 

History: 19 SR 590 

Posted: July 31, 2007 

4715.2220 HOT WATER STORAGE TANKS. 

Subpart 1. Pressure marking of hot water storage tank. Hot water storage tanks shall be 
permanently marked in an accessible place with the maximum allowable working pressure. 

Subp. 2. Drain cocks or valves for hot water storage tanks. Drain cocks or valves for emptying 
shall be installed at the lowest point of each hot water storage tank. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2250 PLUMBING CODE 86 



4715.2230 TANKLESS AND INSTANTANEOUS TYPE HEATERS. 

Tankless and instantaneous type water heaters require pressure relief valves only. Instantaneous electric 
water heaters that have Undenvriters Laboratory approval for use without a relief valve, and that have space 
containing the heating element of less than three inches in diameter, may be installed without a pressure 
relief valve. 

Statutory Authority: MS s 16B.61; 326.37 to 326.45 

History: 15 SR 76 

Posted: July 31, 2007 

4715.2240 ACCESS TO WATER HEATERS. 

Every water heater installation shall be readily accessible for inspection, repair, or replacement. The 
appliance space shall be provided with an opening or doorway of sufficient size to provide such access. 

Exception: A water heater with a tank capacity not greater than six gallons may be concealed in 
a ceiling space provided the water heater has been set in an overflow pan that has been constructed of a 
corrosion-resistant material, has side walls extending at least four inches upward, and has an outlet that 
shall not be sized less than the supply line to the water heater. This outlet shall be piped undiminished in 
size to a point of safe disposal below the ceiling area. No tools shall be required to gain access to a water 
heater. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686 

Posted: July 31, 2007 

4715.2250 DISINFECTION OF POTABLE WATER SYSTEM. 

New or repaired potable water systems shall be disinfected prior to use whenever required by the 
authority having jurisdiction. The method to be followed shall be that prescribed by the health authority or, 
in case no method is prescribed, the following: 

A. the pipe system shall be flushed with clean, potable water until no dirty water appears at the 

points of outlet; 

B. the system or part thereof shall be filled with a water chlorine solution containing at least 
50 parts per million of chlorine and the system or part thereof shall be valved off and allowed to stand for 
24 hours; or 

C. the system or part thereof shall be filled with a water-chlorine solution containing at least 
200 parts per million of chlorine and allowed to stand for three hours; and 

D. following the allowed standing time the system shall be flushed with clean potable water 
until no chlorine remains in the water coming from the system. 

Statutory Authority: MS s 326.37 to 326.45 

History: 17 SR 1279 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



87 PLUMBING CODE 4715.2300 

Posted: July 31, 2007 

4715.2260 [Renumbered 4715.2161] 
Posted: July 31, 2007 

4715.2270 [Renumbered 4715.2162] 
Posted: July 31, 2007 

4715.2280 WATER METER INSTALLATION. 

Water meters shall be placed at least 12 inches above the finished floor and shall be rigidly supported 
with a permanent support in order to prevent the meter from vibrating when the water is passing through it. 

Statutory Authority: MS s 16B.62; 326.37 to 326.45 

History: 19 SR 590 

Posted: July 31, 2007 

DETERMINING SIZE OF DRAINAGE SYSTEM 

4715.2300 LOAD ON DRAINAGE PIPING. 

Subpart 1. Computation of drain load. The load on drainage system piping shall be computed in 
terms of drainage fixture units in accordance with subparts 2, 2a, and 3, except the administrative authority 
may allow variations where it is shown by a hydraulic analysis of the piping system, submitted to the 
administrative authority, that such variation would result in a more desirable flow rate in the piping system. 

Subp. 2. Values for continuous flow. Fixture unit values for continuous or semicontinuous flow 
into the drainage system, such as from a pump, sump ejector, air conditioning equipment, or similar device 
shall be computed on the basis of one fixture unit for each gallon per minute flow. 

Subp. 2a. Values for intermittent flows. Fixture unit values for intermittent flows from appliances 
and equipment which are specially designed for low water use, and used for retrofit in existing plumbing 
systems only, may be determined as follows: 



Discharge Capacity (in gallons 

per minute) Fixture Unit Value 

up to 7-1/2 1 unit 

8 to 15 2 units 

16 to 30 4 units 

31 to 50 6 units 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2300 PLUMBING CODE 



88 



A standpipe used for discharge from such appliances and equipment which is sized using these 

values must be labeled as intended for special low-water-use equipment only. Drainage piping in new 

construction must comply with subpart 3. 

Subp. 3. Table of fixture unit values for various plumbing fixtures. 



Type of Fixture 



Minimimi 
Fixture 
Fixture Unit and Trap 
Value Drain Size 



Clothes washer (domestic use) 

Clothes washer (single unit, discharge to standpipe) 

Clothes washer (public use in groups of 3 or more) 

Bath tub with or without shower 

Bidet 

Dental imit or cuspidor 

Drinking fountain 

Dishwasher, domestic (gravity drain) 

Dishwasher, commercial 

Floor drain with 2 inch waste 

Floor drain with 3 inch waste 

Floor drain with 4 inch waste 

Lavatory 

Laundry tray (1 or 2 compartment) 

Shower stall, domestic 

Shower (gang) per head 

SINKS: 

Classroom, with or without drinking fountain 

Combination, sink and tray (with disposal unit) 

Combination, sink and tray (with one trap) 

Domestic 

Domestic, with disposal unit 

Siffgeons 



2 


1-1/2 


2 


2 


6 each 




2 


1-1/2 


2 


1-1/2 


1 


1-1/4 


1 


1-1/4 


2 


1-1/2 


4 


2 


2 


2 


3 


3 


4 


4 


1 


1-1/4 


2 


1-1/2 


2 


1-1/2 


1 




2 


1-1/2 


3 


1-1/2 


2 


1-1/2 


2 


1-1/2 


2 


1-1/2 


3 


1-1/2 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



89 PLUMBING CODE 4715.2310 



Laboratory, cup sink 




1 


1-1/2 


Flushrim or bedpan washer 




6 


3 


Service 




3 


2 


Pot or scullery 




4 


2 


Soda fountain 




2 


1-1/2 


Commercial, flat rim, bar, or counter 




3 


1-1/2 


Wash, circular, or multiple (per set of faucets) 


2 


1-1/2 


URINAL pedestal, wall hung, with 3 inch 


trap (blowout and syphon jet) 


6 


3 


Wall hung with 2 inch trap 




3 


2 


Wall hung with 1-1/2 inch trap 




2 


1-1/2 


Trough (per 6 foot section) 




2 


1-1/2 


Stall 




3 


2 


WAIER CLOSET 




6 


3 


Unlisted Fixture or Trap Size 








1-1/4 inch 




1 




1-1/2 inch 




2 




2 inch 




3 




2-1/2 inch 




4 




3 inch 




5 




4 inch 




6 





Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 
History: 19 SR 590; 23 SR 686 
Posted: July 31, 2007 

4715.2310 SELECTING SIZE OF DRAINAGE PIPING. 

Subpart 1. Determination of size. Pipe sizes shall be determined from subparts 2 and 3 on the basis 
of drainage load computed from part 4715.2300, subparts 2 and 3. 

Subp. 2. Maximum loads for horizontal drains in fixture units. 



Building Sewer, Building Drain and 
Building Drain Branches - from Stacks**** 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2310 PLUMBING CODE 



90 



Diameter 

of Drain 



Horizontal Fixture 
Branch *- 



Slope 



(inches) 



(f.u.) 



1/16 


1/8 


1/4 


1/2 


in/ft. 


in/ft. 


in/ft. 


in/ft. 


(f.u.) 


(f.u.) 


(f.u.) 


(f.u.) 



1-1/4 

1-1/2 

2 

2-1/2 
3** 

4 

5 

6 

8 

10 

12 

15 

*Includes Horizontal Branches of the Building Drain. 

**No water closet shall discharge into a drain less than 3 inches. 

***Not over 2 Water Closets. 

****Eveiy building drain that receives the discharge of (3) or more water closets, shall not be 
less than 4 inches in diameter 

*****No building sewer shall be less than 4 inches in diameter. 
Subp. 3. Maximum loads for soil and waste stacks in fixture units. 



1 










3 










6 






21 


26 


12 






24 


31 


32*** 




36*** 


42*** 


50*** 


160 




180 


216 


250 


360 




390 


480 


575 


620 




700 


840 


1,000 


- 


1,400 


1,600 


1,920 


2,300 


- 


2,500 


2,900 


3,500 


4,200 


- 


3,900 


4,600 


5,600 


6,700 


- 


7,000 


8,300 


10,000 


12,000 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



91 



PLUMBING CODE 4715.2330 



Stacks of not more than 3 
stories or Branch Intervals 

2 
4 
9 

20 

36*** 

240 

540 

960 









Total at 








One Story 


Stacks of 


more 


than 3 


or Branch 


stories or 


Branch Intervals 


Interval 


2 






1 


4 






2 


18 






6 


42 






9 


72*** 






24** 


500 






90 


1,100 






200 


1,900 






350 


3,600 






600 


5,600 






1,000 


8,400 






1,500 



Diameter of Stack 

1-1/4* 

1-1/2* 

2* 

2-1/2* 

3 

4 

5 

6 

8 — 

10 — 

12 — 

*No water closets permitted. 

**Not over 2 water closets permitted. 

***Not over 6 water closets permitted, and not over 6 branch intervals on a 3 inch soil stack. 
Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326.37 to 326.45 
History: 28 SR 146 
Posted: July 31, 2007 

4715.2320 MINIMUM SIZE OF SOIL AND WASTE STACKS. 

No soil or waste stack shall be smaller than the largest horizontal branch connected thereto except that 
a four by three water closet connection shall not be considered as a reduction in pipe size. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2330 MINIMUM SIZE OF STACK VENT OR VENT STACK. 

Any structure in which a building drain is installed shall have at least one stack vent or vent stack 
carried full size through the roof not less than three inches in diameter. Where one or more soil stacks are 
required to extend through the roof undiminished in size they should be the stack or stacks most remote from 
the location where the building drain leaves the building. When a soil or waste stack receives the discharge 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2360 PLUMBING CODE 92 

of fixtures located on two or more floors, and the uppermost fixture is located three or more floors above the 
building drain, such stack and stack vent shall continue undiminished in size through the roof. For purposes 
of this part, "floor" means any building floor level which is above the floor level of the building drain. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686 

Posted: July 31, 2007 

4715.2340 PROVISION FOR FUTURE FIXTURES. 

When provision is made for future installation of fixtures, those provided for shall be considered in 
determining the required sizes of drain and vent pipes. Construction to provide for such future installations 
shall be terminated with a plugged fitting or fittings. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2350 MINIMUM SIZE OF UNDERGROUND DRAINAGE PIPING. 

No portion of the drainage system installed underground shall be less than two inches in diameter. 
Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

4715.2360 SIZING OF OFFSETS ON DRAINAGE PIPING. 

Subpart 1 . Offsets of 45 degrees or less. An offset in a vertical stack with a change of direction of 
45 degrees or less from the vertical may be sized as a straight vertical stack. 

Subp. 2. Offsets of more than 45 degrees. A stack with an offset of more than 45 degrees from the 
vertical shall be sized as follows: 

A. The portion of the stack above the offset shall be sized as for a regular stack based on the 
total number of fixture units above the offset. 

B. The offset shall be sized as for a building drain branch, part 471 5.23 10, subpart 2. 

C. The portion of the stack below the offset shall be sized at least as large as the offset. 

Subp. 3. Above highest branch. An offset above the highest branch connection is an offset in the 
stack vent and shall be considered only as it affects the developed length of the vent. 

Subp. 4. Below lowest branch. In the case of an offset in a soil or waste stack below the lowest 
branch connection, there shall be no change in diameter required if the offset is made at an angle of not 
greater than 45 degrees from the vertical. 

If such offset is made at an angle of greater than 45 degrees from the vertical, the required diameter 
of the offset and the stack below it shall be sized as for a building drain. (Part 4715.2310, subpart 2.) 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



93 PLUMBING CODE 4715.2410 

Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

4715.2370 FIXTURE CONNECTIONS TO AN OFFSET OF MORE THAN 45 DEGREES OR AT 
BASE OF STACK. 

When stacks in buildings of five or more stories in height receive the discharge of fixtures four or 
more stories above the offset, no fixtures on the floor at wliich the offset occurs shall be connected to the 
stack within eight feet of the base of the offset measured vertically or horizontally. Said fixtures may also 
be connected into vertical section of the stack more than two feet below the offset. Fixture connections to 
horizontal piping at the bases of such stacks shall be made in the same manner, or at a point acceptable to 
the administrative authority. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

DRAINAGE PIPING INSTALLATION 

4715.2400 PITCH ON HORIZONTAL DRAINAGE PIPING. 

Horizontal drainage piping shall be installed in uniform alignment at uniform slopes in accordance 
with the following requirements and in no case at a slope which will produce a computed velocity of less 
than two feet per second, unless otherwise permitted by the administrative authority, based on hydraulic 
analysis of the piping system. 



Size of Piping Minimum Slope 

Less than 3 inches 1/4 inch per foot 

3 inches to 6 inches 1/8 inch per foot 

8 inches and over 1/16 inch per foot 

Statutory Authority: MS s 168.59; 16B.61; 16B.64; 326.37; 326.40 
History: 28 SR 146 
Posted: July 31, 2007 

4715.2410 CHANGE IN DIRECTION. 

Changes in direction in drainage piping shall be made by the appropriate use of 45 degree wyes, long 
or short sweep quarter bends, sixth, eighth, or sixteenth bends, or by combination of these or equivalent 
fittings. Single and double sanitary tees, quarter bends, and long turn ells may be used in drainage lines only 
where the direction of the flow is from the horizontal to the vertical. Short sweep bends or long turn ells 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2430 PLUMBING CODE 94 



three inch or larger in diameter may be used in soil or waste lines where the change in direction of flow is 
from either the horizontal to the vertical or from the vertical to the horizontal. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2420 PROHIBITED FITTINGS AND CONNECTIONS. 

Subpart 1. General prohibitions. No fittings having a hub in the direction opposite to flow, or 
straight tee branch shall be used as a drainage fitting. No fitting or connection which has an enlargement 
chamber or recess with a ledge or shoulder, or reduction in pipe area shall be used. No drainage or vent piping 
shall be drilled, tapped, or welded unless othenvise permitted by the administrative authority. Fittings used 
for bacli-to-back, wall outlet, blowout type water closet bowls shall have a baffle plate or other device to 
prevent the waste water from one water closet from entering the opposite water closet. No fixture connection 
shall be made to a closet bend. No running threads, bands, or saddles shall be used. The short pattern fitting 
in a horizontal position is prohibited in underground work. 

Subp. 2. Heel or side-inlet bends. A heel or side-inlet quarter bend shall not be used as a vent when 
the inlet is placed in a horizontal position or any similar arrangement of pipe or fittings producing a similar 
effect. 

Subp. 3. Obstruction to flow. No fitting, connection, device, or method of installation which 
obstructs or retards the flow of water, wastes, sewage, or air in the drainage or venting system in an amount 
greater than the normal frictional resistance to flow shall be used unless it is indicated as acceptable to this 
code by having a desirable and acceptable function and as of ultimate benefit to the proper and continuing 
functioning of the plumbing system. The enlargement of a three-inch closet bend or stub to four inches 
shall not be considered an obstruction, provided the horizontal flow line or insert is continuous without 
forming a ledge. 

Subp. 4. Dead ends. In the installation of a drainage system, dead ends shall be avoided except 
where necessary to extend piping for a cleanout so as to be accessible. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2430 BUILDING DRAINS BELOW BUILDING SEWER. 

Building drains which cannot be discharged to the sewer by gravity flow shall discharge into an 
approved watertight, gas-tight vented sump or receiving tank, so located as to receive the sewage or 
wastes by gravity. From such sump or receiving tank the sewage or other liquid wastes shall be lifted 
and discharged into the building gravity drain by approved automatic pumping equipment. The system or 
drainage piping entering such sump shall be installed and vented as required in this section for a gravity 
system. 

Statutory Authority: MS s 326.37 to 326.45 

History: 9 SR 1557 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



95 PLUMBING CODE 4715.2500 



4715.2440 DESIGN OF SUMPS. 

Subpart 1 . Construction. Sumps and receiving tanks shall be constructed of poured concrete, metal, 
or other approved materials. If constructed of poured concrete, the walls and bottom shall be adequately 
reinforced and designed to acceptable standards. Metal sumps or tanks shall be of such thickness as to serve 
their intended purpose and shall be treated internally and externally to resist corrosion. 

Subp. 2. Discharge line. The discharge line from such pumping equipment shall be provided with 
an accessible backwater valve and gate valve, and if the gravity drainage line to which such discharge line 
connects is horizontal, the method of connection shall be from the top through a wye branch fitting. The 
minimum size of any pump or discharge pipe from a sump having a water closet connected thereto shall not 
be less than two inches. 

Subp. 3. Sumps for buildings. Building drains or building sewers receiving discharge from any 
pumping equipment shall be adequately sized to prevent overloading. In all buildings, other than single- 
and two-family dwellings, should three or more water closets discharge into the sump, duplicate pumping 
equipment shall be installed. 

Subp. 4. Covers. Sumps and receiving tanks must be provided with gastight covers, except that 
float control or switch rods must operate without binding. The cover must be of a bolt and gasket type or 
equivalent manhole opening to permit access for inspection, repairs, and cleaning. Covers must be metal or 
other structurally sound material that is water-resistant and impervious to moisture, and must be adequate 
to support anticipated loads in the area of use. 

Subp. 5. Single-family dwellings. In single-family dwellings the minimum capacity of a sump shall 
be 18 gallons. 

Subp. 6. Sump vent. The top of the sump tank shall be provided with a vent pipe which shall extend 
separately through the roof, or may be combined with other vent pipes. Such vent shall be large enough 
to maintain atmospheric pressure within the sump under all normal operating conditions and in no case 
less than in accordance with the number of fixture units discharging into the sump. When the foregoing 
requirements are met and the vent, after leaving the sump, is combined with vents from fixtures discharging 
into the sump, the size of the combined vent need not exceed that required for the total number of fixtures 
discharging into the sump. No vent from an air operated sewage ejector shall combine with other vents. 

Subp. 7. Clear water sumps. Sumps and receiving tanks which receive only clear water drainage, 
and from which sewage is excluded, need not be airtight or vented. Sumps and receiving tanks must be 
provided with covers fastened or secured so as to prevent entry by children. The covers must be adequate 
to support anticipated loads in area of use. In nonresidential buildings guard rails constructed in accordance 
with chapter 1305, Minnesota Building Code, may be used in lieu of covers. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 9 SR 1557; 15 SR 76; 19 SR 590; 23 SR 686; 28 SR 146 

Posted: July 31, 2007 

VENTS AND VENTING 
4715.2500 SELECTING SIZE OF VENT PIPING. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2520 PLUMBING CODE 96 



Subpart 1. Size determined. Vent pipe sizes shall be determined from part 4715.2520, subparts 5 
and 6, on the basis of length and drainage load computed from part 4715.2300, subparts 2 and 3. 

Subp. 2. Minimum diameter of vent piping. No vent pipe shall be less than 1-1/4 inches in 
diameter. 

Subp. 3. Individual vents. The diameter of the individual vents shall be determined from part 
4715.2520, subpart 6, but shall in no case be less than one-half the diameter of the fixture drain served. 

Subp. 4. Relief and yoke vents. The diameter of relief and yoke vents shall be at least one-half the 
diameter of the soil and waste branch or stack served, nor less than the size of the vent to which they are 
connected. 

Subp. 5. Circuit or loop vents. The diameter of circuit or loop vents shall be at least one-half the 
diameter of the horizontal soil or waste branch to which they connect. Maximum developed length as shown 
for fixture units in part 4715.2520, subpart 6. See part 4715.2600. 

Subp. 6. Branch vents. The diameter of branch vents connecting more than one individual vent to 
a vent stack or stack vent shall be in accordance with part 4715.2520, subpart 6. The branch vent size shall 
be based upon the number of fixture units connected thereto, and the developed length of the branch vent 
measured from its vent stack (or stack vent) connection to the farthest fixture drain connection served by 
the branch vent. 

Subp. 7. Vent headers. The diameter of vent headers shall be in accordance with part 4715.2520, 
subpart 6. The vent header size shall be based upon the sum of the fixture unit loads at the stacks vented 
through such section of the header, and the developed length shall be that of the vent stack having the longest 
developed length to the open air. 

Subp. 8. Vent stacks. The diameter of the vent stacks shall be determined from part 4715.2520, 
subpart 5, based upon the size of the soil or waste stacks served thereby, the number of fixture units connected 
to the soil or waste stack, and the developed length of the vent stack. Such developed length shall be 
measured from the lowest connection of the vent stack with the soil or waste stack to the open air. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2510 PROTECTION OF TRAP SEALS. 

The protection of trap seals from siphonage or back pressure shall be accomplished by the appropriate 
use of soil or waste stacks or vents, installed in accordance with requirements of this chapter, so that at no 
time the trap shall be subjected to a pressure differential of more than one inch of water. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2520 VENT STACKS AND STACK VENTS. 

Subpart 1 . Vent stack required.Every building in which plumbing is installed shall have at least one 
three-inch vent stack (or stack vent) carried full size throughtheroof as provided in part 4715.2330. A vent 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



97 



PLUMBING CODE 4715.2520 



stack or main vent shall be installed with a soil or waste stack whenever individual vents, relief vents, or 
branch vents are required for stacks of three or more branch intervals. 

Subp. 2. Connections at base and top.For stacks of three or four branch intervals in height, all main 
vents or vent stacks shall connect full size at their base to the main soil or waste stack below, through, or 
not more than 18 inches above the lowest fixture branch. 

For stacks of five or more branch intervals in height, a main vent or vent stack shall connect full size 
with the soil or waste stack it serves, with a wye and one-eighth bend below the lowest fixture branch 
connected to such soil or waste stack, or at a point approved by the administrative authority. 

Each such soil or waste stack, and vent stack shall be similarly cross-connected with a yoke vent at 

intervals of not more than five branch intervals as described in part 4715.2640. 

Subp. 3. Offsets for stacks of five or more branch intervals or stories.As provided in part 
4715.2360, soil and waste stacks offset at an angle of more than 45 degrees from the vertical, that receive 
the discharge of fixtures four or more branch intervals or stories above the offset, shall have a yoke vent 
installed (as per part 4715.2640) at the base of the upper stack section. 

Subp. 4. Vent headers. Where stack vents and vent stacks are connected into a vent header, such 
connections shall be made at the tops of the stacks. The vent header shall connect to a vent extension through 
the roof. 

Subp. 5. Size and lengths of vent stacks. 



DIAMETER OE VENT IN INCHES 



SIZE EIX- 
OF TURE 
SOIL UNITS 
OR CON- 
WASTE NECT- 
STACK EDind. 
IN f. u. 
INCH- 
ES 



1-1/4 1-1/2 



2 2-1/2 



10 



12 



MAXIMUM DEVELOPED LENGTH OF VENT. IN FEET 



1-1/4 
1-1/2 

2 
2 

2-1/2 



2 

4 

9 

18 

42 



50 
40 



200 

100 200 

50 150 

30 100 300 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2520 PLUMBING CODE 98 



3 


72 


4 


240 


4 


500 


5 


540 


5 


1100 


6 


1900 


8 


2200 


8 


3600 


10 


3800 


10 


5600 


12 


6000 


12 


8400 


15 


10500 


15 


50000 



50 


80 


400 














40 


70 
50 


250 

180 

150 

50 


700 

600 

200 

50 


700 

200 

150 

60 


700 
500 
250 
200 
60 


800 
600 
250 
200 
100 
50 


800 
600 
300 
200 

75 


900 
600 
180 



Subp. 6. Size and length of vents; individual, branch, circuit, and header. 



Diameter of Vent, in Inches 

1-1/4 1-1/2* 2 2-1/2 3 4 5 

Fixture Units 
connected in 

d.f.u. Maximum Developed Length of Vent, in Feet 



2 
4 
8 

10 
24 

42 

72 

240 

500 

1100 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



50 


ul 












40 


200 


ul 










np 


150 
100 


250 
200 


ul 










50 


150 


400 


ul 








30 


100 


300 


500 








np 


50 


80 


400 










np 


50 


200 


ul 










np 


180 
50 


700 
200 


ul 
700 



99 PLUMBING CODE 4715.2540 

*Except 6 fixture unit fixtures. 
ul - Unlimited length. 

np - Not permitted. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 
History: 23 SR 686; 28 SR 146 
Posted: July 31, 2007 

4715.2530 VENT TERMINALS. 

Subpart 1. Extension above roofs. Extension of vent pipes through a roof shall be terminated not 
less than 12 inches above it. Where a roof is to be used for any purpose other than weather protection, the 
vent extensions shall be run at least seven feet above the roof. 

Subp. 2. Waterproof flashings. Each vent terminal shall be made watertight with the roof by 
proper flashing of copper, lead, galvanized iron, or other approved flashings or flashing materials. Vent 
pipe terminals shall pass through the roof and shall be at least two inches in diameter. When approved by 
the administrative authority, other materials or methods may be used which provide adequate protection. 

Subp. 3. Location of vent terminal. No vent terminal shall be located directly beneath any door, 
window, or other ventilating opening of the building or of an adjacent building nor shall any such vent 
terminal be within ten feet horizontally of such an opening unless it is at least two feet above the top of such 
opening. 

Subp. 4. Terminals adjoining high buildings. In the event that a new building is built higher than 
an existing building, the owner of the new building shall not locate openable windows, doors, or other 
ventilating openings within ten feet of any existing vent stacli on the lower building unless the owner of 
such new building shall defray the expenses or shall make such alterations to conform to part 4715.2530, 
subpart 3. 

Statutory Authority: MS s 326.37 to 326.45 

History: 17 SR 1279 

Posted: July 31, 2007 

4715.2540 VENT GRADES AND CONNECTIONS. 

Subpart 1. Vent grade. All vent and branch vent pipes shall be so graded and connected as to drain 
back to a soil or waste pipe by gravity. 

Subp. 2. Vertical rise. Where vent pipes connect to a horizontal soil or waste pipe, the vent shall be 
taken off above the center line of the pipe. The vent pipe shall rise vertically, or at an angle not more than 
45 degrees from the vertical, to a point at least six inches above flood-level rim of the fixture it is venting, 
before offsetting horizontally or before connecting to the branch vent. 

Subp. 3. Height above fixtures. A connection between a vent pipe and a vent stack or stack-vent 
shall be made at least six inches above the flood-level rim of the highest fixture served by the vent. Horizontal 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2560 PLUMBING CODE 100 



vent pipes forming branch vents, relief vents, or loop vents shall be at least six inches above the flood-level 
rim of the highest fixture served. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2550 WET VENTING. 

Subpart 1. Single bathroom groups. A single bathroom group of fixtures may be installed with the 
drain from a backvented lavatory, kitchen sink, or combination fixture serving as a wet vent for a bathtub or 
shower stall provided that: 

A. not more than one fixture unit is drained into a 1-1/2 inch diameter wet vent or not more 
than four fixture units drain into a two inch diameter wet vent; and 

B. the horizontal branch drain connects to the stack at or below the same level as the water 
closet (kain when installed on the top floor. 

Subp. 2. Double bathroom groups back-to-back. Bathroom groups back-to-back consisting of two 
lavatories and two bathtubs or shower stalls 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 not 
less than two inches in diameter. 

Subp. 3. Basement shower. Abasementshowermay be wet vented through the waste from a laundry 
tub, lavatory, or sink, provided the wet vent is not less than two inches in diameter, and the drain conforms 
to part 4715.2620, subpart 4. 

Subp. 4. Basement and cellar closet. A basement or cellar lavatory may be connected to a properly 
installed vent from a floor set, basement or cellar, water closet, provided the vent is not less than two inches 
in diameter. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2560 STACK VENTING. 

A group of fixtures consisting of one bathroom group and a kitchen sink or combination fixture may 
be installed without individual fixture vents at the uppermost branch interval of a stack, if each fixture drain 
connects independently to a stack at least three inches in diameter extended full size through the roof, and 
bathtub or shower stall drain enters the stack at or above the same level as the water closet drain, and in 
accordance with requirements in part 4715.2620, subpart 4. Where the trap arm distances are exceeded the 
fixtures must be revented. When a water closet discharges to a sanitary tee in the vertical position, and a 
bathtub or shower on the same floor level also discharges to the sanitary tee through a side inlet, the water 
closet vent must be at least three inches in size unless the bathtub or shower is revented. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 11 SR 1405; 23 SR 686 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



101 PLUMBING CODE 4715.2600 



4715.2570 INDIVIDUAL FIXTURE REVENTING REQUIRED. 

When fixtures other than water closets discharge downstream from a water closet, each fixture 
connecting downstream shall be individually vented, imder provisions set down in this code. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2580 COMMON VENTS. 

Subpart 1. Individual vent as common vent. An individual vent, installed vertically, may be used 
as a common vent for similar fixtures when both fixture drains connect with a vertical drain at the same level. 

Subp. 2. Fixtures connected to vertical drain at different levels. Except for water closets or similar 
fixtures, a common vent may be used for two fixtures set on same floor level but connecting at different levels 
in the vertical drain, provided the vertical drain is one pipe diameter larger than the upper fixture drain but 
in no case smaller than the lower fixture drain, whichever is the larger and that both drains conform to part 
4715.2620, subpart 4. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686 

Posted: July 31, 2007 

4715.2600 CIRCUIT AND LOOP VENTING. 

Subpart 1. Battery venting. A branch or waste pipe to which two, but not more than eight water 
closets (except blowout type) are connected in battery, may be vented by circuit or loop vent which shall be 
taken off in front of the last fixture connection of the battery. When the battery consists of not more than four 
closets, the vent shall be two inches; when the battery consists of five or six closets, the vent shall be 2-1/2 
inches; and when the battery consists of seven or eight closets, the vent shall be three inches. In addition, 
lower floor branches shall be provided with a relief vent which shall be the same size as the branch vent, 
taken off in front of the first fixture connection of the battery. When lavatories, or similar fixtures discharge 
into such branches, each vertical branch from such fixtures shall be provided with a continuous vent. When 
closets are installed back to back, such installation shall be as per subpart 2 or 4. 

Subp. 2. Dual branches. When parallel horizontal branches serve a total of eight water closets (four 
on each branch), each branch shall be provided with a relief vent at a point between the two most distant 
water closets. When fixtures such as lavatories discharge into the horizontal branch drain, each such fixture 
shall be vented. 

Subp. 3. Vent connections. When the circuit, loop, or relief vent connections are taken off the 
horizontal branch, the vent branch connection shall be taken off at a vertical angle or from the top of the 
horizontal branch. 

Subp. 4. Fixtures back-to-back in battery. When fixtures are connected to one horizontal branch 
through a double wye or a sanitary cross 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. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2620 PLUMBING CODE 102 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 
History: 23 SR 686 
Posted: July 31, 2007 

4715.2610 FIXTURES BACK-TO-BACK. 

Two fixtures set back-to-back, within the distance allowed between a trap and its vent, may be served 
with one continuous soil or waste-vent pipe, provided that each fixture wastes separately into an approved 
double fitting, having inlet openings at the same level. {See part 4715.2580, subpart 2.) 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2620 FIXTURE VENTS. 

Subpart 1. Distance of trap from vent. Each fixture trap shall have a protecting vent so located that 
the slope and the developed length in the fixture drain from the trap weir to the vent fitting are within the 
requirements set forth in subpart 4. 

Subp. 2. Trap dip. The vent pipe opening from a soil or waste pipe, except for water closets and 
similar fixtures, shall not be below the weir of the trap. 

Subp. 3. Crown venting limitation. No vent shall be installed within two pipe diameters of the trap 
weir. 

Subp. 4. Distance of fixture trap from vent. 



Size of Fixture Drain, Inches Distance Trap to Vent 

1-1/4 2 ft 6 in 

1-1/2 3 ft 6 in 

2 5 feet 

3 6 feet 

4 10 feet 

Note: The developed length between the trap of the water closet or similar fixture and its vent shall 
not exceed four feet. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



103 PLUMBING CODE 4715.2655 



4715.2630 VENTS FOR FIXTURE TRAP BELOW TRAP DIP. 

Fixture drains shall be vented within the hydraulic gradient between tiie trap outlet and vent connection, 
but in no case shall the unvented drain exceed the distance provided for in part 471 5.2620, subpart 4. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2640 YOKE VENTS FOR STACKS OF MORE THAN FIVE BRANCH INTERVALS. 

Soil and waste stacks in buildings having more than five branch intervals shall be provided with a relief 
vent at each fifth interval installed, beginning with the top floor. The size of the relief vent shall be equal to 
the size of the vent stack to which it connects. The lower end of the yoke vent shall connect to the soil or 
waste stack through a wye and one-eighth bend located below the horizontal branch drain serving fixtures 
on that floor and the upper end shall connect to the vent stack through a tee or inverted wye not less than 
three feet above the floor level. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2650 COMBINATION WASTE AND VENT SYSTEM. 

Subpart 1. Where permitted. A combination waste-and-vent system shall be permitted only where 
structural conditions preclude the installation of a conventional system as otherwise provided in this code. 

Subp. 2. Limits of use. A combination waste-and-vent system is limited to floor drains and sinks 
which will not be used for greasy wastes. It consists of an installation of waste piping in which the trap of 
the fixture is not individually vented. Every drainage pipe and trap in the waste and vent system shall be at 
least two pipe sizes larger than the size required in part 4715.2310. Vents shall be provided at both ends of 
the system. 

Subp. 3. [Repealed, 28 SR 146] 

Statutory Authority: MSs 16B.59; 16B.61; 16B.64; 326.37; 326.40 

History: 28 SR 146 

Posted: July 31, 2007 

4715.2655 ISLAND FIXTURE VENTING. 

Traps for island sinks and similar equipment may be vented, when structural conditions preclude the use 
of conventional vents, by extending the vent as high as possible under the sink enclosure and then returning 
it downward and connecting it to the horizontal drain through a wye branch fitting downstream from the 
vertical fixture drain. In addition, a horizontal vent must be taken off the vertical section of the fixture vent 
by means of a wye branch fitting and extended to the partition where it can be extended vertically to the 
open air or connected to another vent at least six inches above the flood level of the fixture served. Drainage 
fittings must be used on all sections of the vent below floor level and a minimum slope of one-fourth inch 
per foot to the drainage point shall be provided. Cleanouts must be provided on the vent piping. 

Statutory Authority: MSs 16B.59; 16B.61; 16B.64; 326.37; 326.40 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2710 PLUMBING CODE 104 

History: 28 SR 146 
Posted: July 31, 2007 

4715.2660 VENTING OF SUMPS AND SEWERS. 

Drainage piping below sewer level shall be vented in similar manner to that for a gravity system. 
Building sump vents shall be sized in accordance with parts 4715.2520, subpart 6, and 4715.2440, subpart 
6, but in any case not less than 1-1/2 inches. Vents from pneumatic ejectors, flammable waste traps, or 
similar equipment shall be terminated separately at the open air. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

STORM DRAINS 

4715.2700 STORM SEWER SYSTEMS. 

All roofs shall be drained into a separate storm sewer system, or a combined sewer system where such 
systems are available, or to a place of disposal satisfactory to the administrative authority. In no case shall 
water from roofs be allowed to flow upon the public sidewalk. Storm water shall not be drained into sewers 
intended for sanitary sewage only. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2710 SIZE OF BUILDING STORM DRAINS AND LEADERS. 

Subpart 1 . Size of building storm drain. The size of the building storm drain or any of its horizontal 
branches having a slope of one-half inch or less per foot, shall be based upon the maximum projected roof 
or paved area to be handled according to subpart 4. 

Subp. 2. Size of vertical leaders. Vertical leaders shall be sized on the maximum projected roof 
area, according to subpart 5. 

Subp. 3. Reduction in size prohibited. Storm drain piping shall not reduce in size in the direction 
of flow, including changes in direction from horizontal to vertical. 

Subp. 4. Size of horizontal storm drains. 



Maximum projected Roof Area for Drains of 
Diameter of Drain Various Slopes 

Inches 1/8 in. Slope 1/4 in. Slope 1/2 in. Slope 

Square Feet Square Feet Square Feet 



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105 PLUMBING CODE 4715.2710 

3 822 1,160 1,644 

4 1,880 2,650 3,760 

5 3,340 4,720 6,680 

6 5,350 7,550 10,700 
8 11,500 16,300 23,000 
10 20,700 29,200 41,400 
12 33,300 47,000 66,600 
15 59,500 84,000 119,000 

Use a rate of rainfall of four inches per hour for sizes not listed in this table. 

Subp. 5. Size of vertical leaders. 



Size of Leader or Conductor Maximum Projected Roof Area 

Inches Square Feet 

2 720 
2-1/2 1,300 

3 2,200 

4 4,600 

5 8,650 

6 13,500 
8 29,000 

Use a rate of rainfall of four inches per hour for sizes not listed in this table. 

The equivalent diameter of square or rectangular leader may be taken as the diameter of that circle 

which may be inscribed within the cross-sectional area of the leader. 

Subp. 6. Values for continuous flow. If there is a continuous or semi continuous discharge into the 
building storm drain or building storm sewer, as from a pump, ejector, air-conditioning plant, or similar 
device, each gallon per minute of the discharge must be computed as being equivalent to 24 square feet of 
roof area, based upon a four-inch rainfall. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2750 PLUMBING CODE 106 



4715.2720 SUBSOIL DRAINS. 

When the subsoil drain for a building is subject to backwater, it shall be protected by an accessibly 
located backwater valve. Subsoil drains may discharge into a properly trapped area drain or sump. Such 
sumps do not require vents. (See parts 4715.2430 and 4715.2440.) 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2730 BUILDING SUBDRAINS. 

Building subdrains, receiving subsoil drainage, located below the public sewer level shall discharge 
into a sump or receiving tank the contents of which shall be automatically lifted and discharged into the 
drainage system as required for building sumps. (See parts 4715.2430 and 4715.2440.) 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2740 TRAPS ON STORM DRAINS AND LEADERS. 

No traps shall be required for stormwater drains which are connected to a sewer carrying storm water 
exclusively. 

Leaders and storm drains that are connected to a combined sewer shall be trapped if: 

A. the drain is located within ten feet of any door, window, or other opening into an occupied 

area; and 

B. an outside leader of sheet metal is connected to the storm drain and the joint of connection 
is witiiin ten feet of any door, window, or other opening into an occupied area. Such connection shall be at 
least six inches above grade. The trap shall be located inside the building and be provided with an accessible 
cleanout. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2750 CONDUCTORS AND CONNECTIONS. 

Subpart 1. Not to be used improperly. Conductor pipes shall not be used as soil, waste, or vent 
pipes nor shall drainage or vent pipes be used as conductors. 

Subp. 2. Separate storm and sanitary drainage. The sanitary and storm building drains shall 
be separate and shall be run to a point at least five feet outside the building. The sanitary and storm 
building sewers shall be separate except where a combined sewer is available and where permitted by local 
authorities they may be joined together preferably in a manhole prior to discharging to a combined sewer. 
The sizing of the combined building sewer shall conform to good engineering practices and be acceptable 
to the administrative authority. 

Statutory Authority: MS s 326.37 to 326.45 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



107 PLUMBING CODE 4715.2780 



Posted: July 31, 2007 

4715.2760 ROOF AND DECK DRAINS. 

Subpart 1. Roof drain strainers. All roof areas, except those draining to hanging gutters, shall be 
equipped with roof drains having strainers extending not less than four inches above the surface of the roof 
immediately adjacent to the roof drain. Strainers shall have an available inlet area, above roof level, equal 
to that of the conductor or leader to which the drain is connected. 

Subp. 2. Overflow drains. For overflow drains refer to chapter 1305, Minnesota Building Code. 

Subp. 3. Flat deck and area drains. Drain strainers for use on sun decks, and similar area, normally 
serviced and maintained, may be of the flat surface type, level with the deck and shall have an available inlet 
area of not less than two times the area of the conductor or leader to which the drain is connected. 

Subp. 4. Roof drain flashings required. The connection between roofs and roof drains which pass 
through the roof and into the interior of the building shall be made watertight by use of proper flashing 
material. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686; 28 SR 146 

Posted: July 31, 2007 

4715.2770 PROVISIONS FOR EXPANSION. 

Expansion joints, sleeves, or suitable offsets shall be provided where warranted by temperature 
variations or physical conditions. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2780 CONTROL FLOW STORM WATER DRAINAGE FOR DEAD LEVEL ROOFS. 

Subpart 1. General requirements. In lieu of sizing the storm drainage system from conventional 
methods as previously described in this chapter, the roof drainage may be sized on the controlled flow and 
storage of the storm water on the roof provided the following conditions are met: 

A. the roof drainage system shall be sized on the basis of a rate of rainfall of four inches per 
hour; 

B. die roof is dead level and 45 degree cants, properly flashed, are installed at any well or 
parapet; 

C. the roof design is based on a minimum of 40 pounds per square foot live load, with overflow 
line of roof edge, coping, or relieving scupper in parapet wall at least four inches in height above the roof 
and at no greater height than will provide a safety factor of two for the structural design live load; 

D. roof drainage pipe sizing may be designed on the basis of controlled flow sizing tables 
provided by manufacturers of roof drains approved by the administrative authority or by the tables in subparts 
2 and 3; 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2800 PLUMBING CODE 108 



E. the plans or specifications for the storm drainage system shall indicate the method used as 
the basis for the design. 



Subp. 2. Size of vertical leaders. 



Maximum Projected Roof Area 
Size of Leader Inches in Square Feet 

3 7,500 

4 15,000 

5 21,000 

Roof areas of more than 15,000 square feet shall contain two or more roof drains. 
Subp. 3. Size of horizontal storm drains. 



Diameter of Drain Maximum Projected Roof Area in Square Feet 

Inches 1/4 in. Slope 

3 3,500 

4 8,200 

5 11,750 

6 18,500 
8 40,000 
10 75,850 
12 118,000 
15 214,000 

Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

INSPECTION, TESTS, AND MAINTENANCE 

4715.2800 INSPECTIONS. 

New plumbing systems and parts of existing systems which have been altered, extended, or repaired 
shall be inspected and tested by the proper administrative authority to ensure compliance with all the 
requirements of this code and the installation and construction of the system in accordance with the 



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109 PLUMBING CODE 4715.2820 



approved plan and the permit, except that testing may be waived for work which does not include addition 
to, replacement, alteration, or relocation of any water supply, drainage, or vent piping. 

All the piping shall be tested and after the plumbing fixtures have been set, and before the system is 
put into use, the system shall be given a final inspection and test by the proper administrative authority. 

The equipment, material, power, and labor necessary for the inspection must be furnished by the 
plumbing contractor. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 23 SR 686 

Posted: July 31, 2007 

4715.2810 NOTIFICATIONS. 

It shall be the duty of the plumbing contractor to notify the proper administrative authority and the 
owner or the owner's authorized agent orally, by telephone, or in writing, not less than eight working hours 
between the hours of 8:00 a.m. and4:00p.m. before the work is to be inspected or tested. It shall be the duty 
of the plumbing contractor to make sure that the work will stand the test prescribed before giving the above 
notification. If the proper administrative authority finds that the work will not stand the test, the plumbing 
contractor shall be required to renotify as above. If the proper administrative authority does not appear for 
an inspection within 24 hours of the time set, excluding Saturdays, Sundays, and holidays, the inspection or 
test shall be deemed to have been made, and the plumbing contractor is required to file an affidavit with the 
proper administrative authority that the work was installed in accordance with the code, the approved plans 
and permit, and that it was free from defects and that the required tests had been made and the system found 
free from leaks; also whether the owner or the owner's authorized agent was present when such inspection 
or test was made. 

Statutory Authority: MS s 326.37 to 326.45 

History: 17 SR 1279 

Posted: July 31, 2007 

4715.2820 METHOD OF TESTING. 

Subpart 1. Testing, The air tests shall be applied to the plumbing drainage system in its entirety or 
in sections. Sections which are found satisfactory need not be retested after completion of the entire system 
unless considered necessary by the proper administrative authority. 

Subp. 2. Rough plumbing. The piping of plumbing drainage and venting systems shall be tested 
upon completion of the rough piping. The method of testing shall be specified by the designer and shall 
either be an air test or hydrostatic test as described in this subpart or an alternative test as approved by the 
administrative authority. The air test shall be made by attaching the air compressor or testing apparatus to 
any suitable opening and closing all other inlets and outlets to the system by means of proper testing plugs. 
Plaster of paris shall not be used in roof terminals. Air shall be forced into the system until there is a uniform 
pressure of five pounds per square inch on the portion of the system being tested. The pressure shall remain 
constant for 15 minutes without the addition of air. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.2820 PLUMBING CODE 110 

The hydrostatic test for thermoplastic piping materials shall be conducted by tightly closing all 
openings in the entire system to be tested except the highest opening. The system shall be filled with 
water to the point of overflow. If the system is tested in sections, each opening shall be tightly plugged 
except the highest opening of the section under test. Each section shall be filled with water, but a section 
shall not be tested with less than ten foot head of water. In testing successive sections, at least the upper 
ten feet of the next preceding section shall be tested, so that no joint or pipe in the building, except the 
uppermost ten feet of the system, is subjected to a test of less than ten 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 begins. 
The system shall be tight at all points. 

In lieu of five pound air test, concrete manholes and sewer lines may be tested by negative pressure 

in accordance with ASTM Standards C1214-92 and C1244-93. 
Subp. 2a. Exceptions. 

A. Testing is not required for: 

(1) outside leaders; 

(2) perforated or open drain tile; or 

(3) portions of storm sewers located more than ten feet from buildings, more than ten 
feet from buried water lines, and more than 50 feet from water wells, and not passing through soil or water 
identified as being contaminated. 

B. Building storm sewers may be tested in accordance with the Hydrostatic Test Method from 
the City Engineers Association of Minnesota, except that an air test may be required for any section of 
the building storm sewer that passes through contaminated soils or contaminated water. The Hydrostatic 
Test Method, provisions H2 and H3, as specified in Standard Utilities Specifications for Watermain and 
Service Line Installation and Sanitary Sewer and Storm Sewer Installation, written and published by the City 
Engineers Association of Minnesota, 1988 edition, is incorporated by reference, is not subject to frequent 
change, and is available in the office of the commissioner of administration. 

Subp. 3. Finished plumbing. After the plumbing fixtures have been set and their traps filled with 
water, their connections shall be tested and proven gas and water tight by plugging the stack openings on 
the roof and the building drain where it leaves the building, and air introduced into the system equal to 
the pressure of a one inch water column. Such pressure shall remain constant for the period of inspection 
without the introduction of additional air. 

Subp. 4. Conductor pipes. Conductor pipes and their roof connections inside the building shall be 
tested with air. (See subpart 2) 

Subp. 5. Test of water distribution system. Upon the completion of a section or of the entire water 
distribution system, it shall be tested and proved tight with the use of air or water not less than the maximum 

Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



Ill PLUMBING CODE 4715.2850 



working pressure under which it is to be used. If tested with water, the water used for the test shall be 
obtained from a potable source. 

Subp. 6. Material and labor for tests. The equipment, material, power, and labor necessary for the 
inspection and test shall be furnished by the plumbing contractor. 

Subp. 7. Test plugs or caps. Test plugs or caps for roof terminals must extend above or outside the 
end of the vent pipe to provide a visible indication for removal after the test has been completed. 

Statutory Authority: MS s 16B.59 to 16B. 75; 326.37 to 326.45 

History: 19 SR 590; 23 SR 686; 28 SR 146 

Posted: July 31, 2007 

4715.2830 COVERING OF WORK. 

No building drainage or plumbing system or part thereof shall be covered until it has been inspected, 
tested, and approved as herein prescribed. 

If any building drainage or plumbing system or part thereof is covered before being regularly 
inspected, tested, and approved, as herein prescribed, it shall be uncovered upon the direction of the proper 
administrative authority. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2840 DEFECTIVE WORK. 

If the inspection or test shows defects, such defective work or material shall be replaced and the 
inspection and test repeated. 

All installed fixtures found defective or in an insanitary condition shall be repaired, replaced, or 
removed upon written notice from the proper administrative authorities. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2850 AIR TEST OF DEFECTIVE PLUMBING. 

The air test shall be used in testing the sanitary condition of the drainage or plumbing system of all 
buildings where there is reason to believe that it has become defective. In buildings condemned by the 
proper administrative authority because of insanitary conditions of the plumbing system, the alterations in 
such system shall not be considered as repairs, but as new plumbing. 

Where buildings are moved from one location to another, or raised for foundations, or where part of 
the plumbing system has been damaged by fire, storm, or other means, a final air test shall be applied and 
shall hold tight, if in the opinion of the administrative authority it is warranted in order to assure a sanitary 
plumbing system. 

Statutory Authority: MS s 326.37 to 326.45 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3130 PLUMBING CODE 112 

Posted: July 31, 2007 

4715.2860 MAINTENANCE. 

The plumbing system of every building shall be maintained in a sanitary and safe operating condition. 
Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

4715.2870 DISINFECTION OF WATER PIPING. 

See part 4715.2250. 
Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

4715.2880 BUILDING SEWER. 

The building sewer shall be inspected by the proper administrative authority to ensure compliance with 
the provisions of the code. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.2890 CERTIFICATE OF APPROVAL. 

Upon the satisfactory completion and final inspection of the plumbing system, a certificate of approval 
shall be issued by the proper administrative authority. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

PLUMBERS AND PLUMBING; REQUIREMENTS 

4715.3130 PLANS AND SPECIFICATIONS. 

Prior to the installation by any person, corporation, or public agency, of a system of plumbing that 
serves the public or that serves any considerable number of persons, or any plumbing system that shall 
affect the public health in any manner, complete plans and specifications, together with any additional 
information that the commissioner of health may require, shall be submitted in duplicate and approved 
by the commissioner. The appraisal of the commissioner shall reflect the degree to which these plans and 
specifications affect the public health and conform to the provisions of the Minnesota Plumbing Code. No 
constructions shall proceed except in accordance with approved plans. Any material alteration or extension 
of the existing system shall be subject to these same requirements. This rule shall not apply to cities of 
the first class, except those plumbing installations in hospitals or in buildings in these cities owned by the 
federal or the state government. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



113 PLUMBING CODE 4715.3150 



There shall be no physical connection between water supply systems that are safe for domestic use 
and those that are unsafe for domestic use. There shall be no apparatus through which unsafe water may be 
discharged or drawn into a safe water supply system. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.3140 EXAMINATION AND LICENSING OF PLUMBERS. 

Subpart 1. Examinations. An applicant for a plumber's license must satisfactorily pass an 
examination given by the commissioner of health. Examinations for journeyman and master plumber 
licenses shall be held in March and September of each year Applications for the March examination must 
be filed not later than February 15 and for the September examination not later than August 15. 

A. An applicant for the master plumber examination must, in addition to the practical plumbing 
experience requirement for a master plumber specified in subpart 2, have at least one of the following: 

(1) a current Minnesota journeyman plumber license; 

(2) a master plumber license from another state where the requirements of the licensing 
jurisdiction are equivalent to those of Minnesota, as determined by the commissioner; or 

(3) five years of verifiable experience in business as a plumbing contractor in Minnesota. 

B. An applicant for the journeyman examination must be a registered apprentice in Minnesota 
and have satisfied the practical plumbing experience requirement specified in subpart 2 for a journeyman 
plumber or must hold a current state journeyman plumber's license from another state where the licensing 
jurisdiction requires at least four years of practical plumbing experience and an examination to qualify for 
licensure. 

Subp. 2. Experience. An applicant for the journeyman plumber's license examination must have 
not less than four years of practical plumbing experience and the applicant for a master plumber's license 
examination must have not less than five years of practical plumbing experience. 

A. One year of practical plumbing experience consists of at least 1,750 hours. 

B. Not more than two years of the practical plumbing experience from a state other than 
Minnesota shall be credited unless the applicant first obtains a plumber's license in the other state. 

C. The apprentice or applicant is responsible for verifying practical plumbing experience. The 
commissioner of health may require work records, time cards, pay records, or other documentation necessary 
to evaluate practical plumbing experience. The commissioner shall make the final determination about the 
adequacy and acceptability of an apprentice's or applicant's practical plumbing experience. 

Statutory Authority: MSs 16A.128; 16A.1285; 144.12; 326.37 to 326.45; 326.57 to 326.65 

History: 18 SR 1519 

Posted: July 31, 2007 

4715.3150 FEES. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3170 PLUMBING CODE 114 



Subpart 1. Examination application fee. Applications to take the journeyman or master plumber's 
examination must be submitted to the commissioner of health on forms prepared by the commissioner 
together with a fee of $50. The fee must be submitted with the application and is not refundable. 

Subp. 2. Fees for license. Any applicant who receives a passing grade on the examination may 
submit an application for license on forms prepared by the commissioner of health. The application must 
be accompanied by a fee of $55 for a journeyman plumber's license or $120 for a master plumber's license, 
except that an application for initial licensure that is submitted during the last three months of a licensing year 
must be accompanied by a fee of $27.50 for a journeyman plumber's license or $60 for a master plumber's 
license. 

Statutory Authority: MS s 16A.128; 16A.1285; 144.12; 326.37 to 326.45; 326.57 to 326.65 

History: 10 SR 1687; 12 SR 624; 18 SR 1519 

Posted: July 31, 2007 

4715.3160 EXPIRATION OF LICENSES. 

Subpart 1 . Issuance and expiration. Initial and renewal journeyman and master plumber's licenses 
shall be issued for the calendar year for which application is made and shall expire on December 3 1 of such 
year. Any journeyman or master plumber who submits a renewal application after December 31 shall not 
work as a journeyman or master plumber until the person has submitted an application, fee, and penalty fee. 
Any licensee who does not renew a license within two years is no longer eligible for renewal. Such person 
must retake and pass the examination before a new license will be issued. 

Subp. 2. License renewals. Applications for license renewal must be submitted to the commissioner 
of health on forms prepared by the commissioner no later than December 31 of the year preceding the year 
for which application is made. The application must be accompanied by a fee of $55 for a journeyman 
plumber and $120 for a master plumber. Journeyman and master plumbers who submit their license renewal 
applications after the time specified in subpart 1 but within two years after expiration of the previously issued 
license must pay all past due renewal fees plus an additional $25. 

Subp. 3. Fee for filing bond and insurance. Master plumbers who file a bond and evidence of 
liability insurance with the secretary of state, pursuant to Minnesota Statutes, section 326.40, shall pay an 
additional fee of $40. 

Statutory Authority: MS s 16A.128; 16A.1285; 144.12; 326.37 to 326.45; 326.57 to 326.65 

History: 10 SR 1687; 17 SR 1279; 18 SR 1519 

Posted: July 31, 2007 

4715.3170 REGISTRATION OF PLUMBER'S APPRENTICE. 

Efiective July 1, 1987, no person shall work as a plumber's apprentice until that person has submitted 
an application and fee for registration to the commissioner of health. Registration must be renewed annually 
and shall be for the period from July 1 of each year to June 30 of the following year. Applications for initial 
and renewal registration must be submitted to the commissioner of health before July 1 of each registration 
period on forms provided by the commissioner, and must be accompanied by a fee of $25. A plumber's 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



115 PLUMBING CODE 4715.3500 

apprentice who submits a registration application after July 1 in any year must pay the past due renewal fee 
plus an additional $25 late fee. 

A. A plumber's apprentice must be at least 18 years of age or be a high school graduate, except 

that an apprentice employed and supervised by the apprentice's parent must be at least 16 years of age. 

B. At the time of registration, an apprentice must provide a name, address, date of birth, social 
security number, and information about education and practical plumbing experience on forms prepared by 
the commissioner of health. 

C. The practical plumbing experience for an apprentice must include at least the following 
number of hours in the plumbing aspects specified in subitems (1) to (3). The remaining required hours of 
practical plumbing experience may be in any aspect of plumbing work included in the definition of plumbing 
in part 4715.0100, however, the type of work and corresponding number of hours must be specified: 

(1) water distribution system installation, 2,000 hours; 

(2) drain, waste, and vent system installation, 2,000 hours; and 

(3) fixture installation, 1,000 hours. 

D. All practical plumbing experience for an apprentice must be certified by the licensed 
plumber or plumbing contractor responsible for the work performed. A licensed plumber or plumbing 
contractor may only certify that part of the practical plumbing experience work done under the licensed 
plumber's or plumbing contractor's supervision. 

E. Only practical plumbing experience gained in the 12-month period immediately prior to 
registration or submission of the renewal application for registration shall be considered, except that late 
registration renewals may be accepted for a period not exceeding three months, with payment of a late fee. 

F. The 1,750 hours necessary to gain one year of practical plumbing experience may be worked 
in more than one 12-month registration period as a plumber's apprentice, however, not more than 1,750 hours 
shall be credited for one registration period. 

Statutory Authority: MS s 16A.128; 16A.1285; 144.12; 326.37 to 326.45; 326.57 to 326.65 

History: 12 SR 624; 18 SR 1519 

Posted: July 31, 2007 

EXPLANATORY MATERIALS 

4715.3500 GENERAL. 

Parts 4715.3500 to 4715.3700 outline a procedure for the sizing of the water supply piping. The design 
procedure is based on the minimum pressure available from the street main or individual source of supply, 
the head changes in the system due to friction and elevation, the volume rates of flow required for satisfactory 
operation of the fixtures, and the probability of simultaneous use. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3600 PLUMBING CODE 



116 



4715.3600 TOTAL DAILY WATER REQUIREMENTS. 

Subpart 1. Basic needs. The calculation of total daily requirements for water may be based on the 
unit quantities shown in subparts 2 and 3. The total daily water requirement does not constitute the peak or 
simultaneous water requirement of the supply and shall not be used in sizing water distribution systems. The 
total of the daily water requirement shall be used only to determine whether the source of the water supply 
is suf&cient to provide the water requirements of people, animals, irrigation, and other water using facilities 
served. The rate of flow and pressures at which the total daily water requirements shall be delivered shall 
be determined as prescribed hereinafter. 

Subp. 2. Design criteria for daily water requirements based on building occupancy. 



Type of occupancy 



Minimum quantity 
of water per person 
per day in gallons 
(or as indicated) 



Small dwellings and cottages with seasonal occupancy 

Single family dwellings 

Multiple family dwellings (apartments) 

Rooming houses 

Boarding houses 

Additional kitchen usage for nonresident boarders 

Hotels without private baths 

Hotels with private baths (2 persons per room) 

Restaurants (toilet and kitchen usage per patron) 

Restaurants (kitchen usage per meal served) 

Additional for bars and cocktail lounges 

Tourist camps or trailer parks with central bathhouse 

Tourist camps or mobile home parks with individual bath units 

Resort camps (night and day) with limited plumbing 

Luxury camps 

Work or construction camps (semipermanent) 

Camp (with complete plumbing) 

Camp (with flush toilets-no showers) 

Day camps (no meals served) 

Day schools, without cafeterias, gymnasiums, or showers 



50 

75 

60 

40 

50 

10 

50 

60 

7 to 10 

2-1/2 to 3 

2 

35 

50 

50 

100 to 150 

50 

45 (Ind.w.s.) 

25 (Ind.w.s.) 

15 

15 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



117 



PLUMBING CODE 4715.3600 



Day schools with cafeterias, but no gymnasiums or showers 

Day schools with cafeterias, gymnasiums and showers 

Boarding schools 

Day workers at schools and offices {per shift) 

Hospitals (per bed) 

Institutions other than hospitals (per bed) 

Factories (gallons per person per shift, exclusive of industrial wastes) 

Picnic parks (toilet usage only) (gallons per picnicker) 

Picnic parks with bathhouses, showers, and flush toilets 

Swimming pools and bathhouses 

Luxury residences and estates 

Country clubs (per resident member) 

Country clubs (per nonresident member) 

Motels (per bed space) 

Motels with bath, toilet, and kitchen range 

Drive-in theaters (per car space) 

Movie theaters (per auditorium seat) 

Airports (per passenger) 

Self-service laundries (gallons per wash, i.e., per customer) 

Stores (per toilet room) 

Service stations (per vehicle serviced) 

Subp. 3. Daily water requirements for common farm animals. 



20 

25 

75 to 100 

15 

150 to 250 

75 to 125 

15 to 35 

5 

10 

10 

100 to 150 

100 

25 

40 

50 

5 

5 

3 to 5 

50 

400 

10 



Animal 



Minimum daily water 
requirements in gallons 



Horse, mule, or steer 

Dairy cow (drinking only) 

Dairy cow (drinking and dairy servicing) 

Sheep 

Hog 

Chickens (100) 

Turkeys (100) 



12 
15 

35 

2 

4 

4 

7 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 118 



Subp. 4. Calculating total daily requirement. Total daily water requirements should be calculated 
by multiplying the unit daily requirement by the total number of persons in the occupancy involved. 
See subpart 6. To this figure must be added any special use quantity, such as lawn watering, industrial 
requirement, etc. 

Subp. 5. Special requirements. The total daily amount of any special requirement shall be added 
to the figure as obtained under subpart 4. Part 4715.1770, subpart 2 gives special use quantities for some 
conditions. While the quantity of special use water shall be computed on the rates given in part 4715.1770, 
subpart 2, the total amount shall be figured for appropriate periods and conditions of use. See subpart 7. 

Subp. 6. Example 1. Example: assume there is a hospital outside the limits of a community. The 
hospital has 300 beds. In addition, the hospital supplies its own dairy products and has a farm with 40 head 
of cattle. In subpart 2, the daily water requirement per hospital bed is taken as 250 gallons per bed. From 
subpart 3, the water requirement per head of cattle is taken as 35 gallons per animal. Therefore the total 
daily water requirement is 300 x 250 plus 40 x 35 or 76,400 gallons. 

Subp. 7. Example 2. Example: it is assumed that at the hospital cited in subpart 6 there is a lawn 
sprinkling system operating from 12 sill cocks three hours each day. From part 4715.1770, subpart 2 it is 
seen that each sill cock requires 300 gallons per hour. Therefore, the total special use water will equal 12 x 
300 X 3 or 10,800 gallons. This amount is added to that obtained in subpart 6. The total quantity required 
is, therefore, 76,400 plus 10,800 or 87,200 gallons per day. 

Statutory Authority: MS s 326.37 to 326.45 

Posted: July 31, 2007 

4715.3700 DETERMINATION OF PEAK DEMAND. 

Subpart 1. Estimating water supply demand. In determining the size of water supply distribution 
piping, the maximum momentary volume rate of flow of water shall first be determined. This is the supply 
demand which is based on the numbers and kinds of fixtures installed, on the rates of flow required by the 
different kinds of fixtures, and on the probable simultaneous operation of the various fixtures. The total 
daily requirements do not enter into this determination. In computing supply demand, use shall be made of 
subpart 2. 

Subp. 2. Supply fixture unit values for various plumbing fixtures. 



Fixture of group Type of supply control 



Bathroom group 


Flush valve 


Bathroom group 


Flush tank 


Bathtub 


Faucet 


Combination fixture 


Faucet 


Kitchen sink 


Faucet 



Supply 


fixture unit values 


Hot 


Cold 


TotaP 


3 


6 


8 


3 


4.5 


6 


1.5 


1.5 


2 


2 


2 


3 


1.5 


1.5 


2 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



119 



PLUMBING CODE 4715.3700 



Laundry tray 
Lavatory 
Pedestal urinal 
Restaurant sink 
Service sink 
Shower head 
Stall or wall urinal 
Stall or wall urinal 
Water closet 
Water closet 



Faucet 
Faucet 
Flush valve 
Faucet 
Faucet 
Mixing valve 
Flush valve 
Flush tank 
Flush valve 
Flush tank 



2 


2 


3 


1.5 


1.5 


2 




10 


10 


3 


3 


4 


1.5 


1.5 


2 


3 


3 


4 




5 


5 




3 


3 




10 


10 




5 


5 



^For fixtures not listed, factors may be assumed by comparing the fixture to a listed one using water in 
similar quantities and at similar rates. 

^For fixtures with both hot and cold water supplies, the weights for maximum separate demands 

may be taken as three-fourths of the total supply fixture unit value. 

Subp. 3. Calculation of demand. When the water supply fixture units are used to estimate the supply 
demand, the supply fixture unit values as given in subpart 2 shall be used in conjunction with subpart 4. 

Subp. 4. Supply demand for various loads in supply fixture units. 



Load 



Supply fixture 
units: 



Supply demand 



Flush valve water closets predominate 
(subpart 5, curve 1) 

gpm 



Tank water closets 

predominate 
(subpart 5, curve 2) 

gpm 



5 

10 

20 

30 

40 

50 

60 



22 
27 
35 
42 
46 
51 
54 
64 



4 
8 
14 

20 
24 
28 
32 
40 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 120 

124 74 48 

160 81 56 

226 98 72 

300 108 85 

400 127 106 

470 135 118 

500 143 124 

600 157 143 

660 162 152 

700 170 161 

800 183 178 

850 189 185 

900 197 195 

1,000 208 208 

1,060 216 216 

1,280 243 243 

1,510 270 270 

1,990 324 324 

2,480 378 378 

2,990 432 432 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



121 



PLUMBING CODE 4715.3700 



Subp. 5. Graph of supply demand for various loads in supply fixture units. 



SOD 




! t ■ ' 1 i ■ 






V • 1 ■ 




1 1 1 






\ ' ' 
















J_L...L 




I — \ |-i- .L-U 1-1 ' 1 1 i 1 1 i l-.U-iJ4-J-Lul44--l \- U 






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_:_:::::!_:..: :_:!._--. __ __ -j 



500 1000 1500 2000 

SUPPLY nXTURE UNITS 



2b00 



3000 





— ■ 


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~ 


~ 


'~ 


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SUPPLY nXTURE UNITS 

The estimated demand load in gallons per minute for fixtures used intermittently on any water supply 
pipe shall be obtained by multiplying the total number of each kind of fixture, supplied through that pipe 
by its supply fixture unit value from subpart 2, adding the products, and then, referring to the appropriate 
columns of subpart 4, or using subpart 5, select the demand in GPM. Examples are given below. The 
additional load of any continuously flowing outlets such as hose outlets shall be computed separately and 
added to the total demand of intermittently used fixtures. See subpart 6. 

Subp. 6. Example. Assume a water line serving a public washroom in which are three flushometer 
pedestal urinals, six flushometer closets and six lavatories with hot and cold water. First prepare a tabulation 
as shown. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 



122 



Name of Number on 

plumbing system (or 

fixture section) 



Supply fixture unit value per 
fixture (Subpart 2) 



Total supply fixture units 



Pedestal 
Urinal, Flush 
Valve 



Hot 



Cold 



10 



Total 



10 



Hot Cold Total 



30 



30 



Flushometer 
Closet 



10 



10 



60 



60 



Lavatory 6 

Total 

Supply demand in GPM 



1.5 



1.5 



9 


9 


12 


9 


99 


102 


7 


67 


68 



See subpart 8. 

Referring to subpart 2 for these fixtures, it is found that the total demand in supply fixture units 
for hot was 9 sT.u., for cold was 99 s.f.u., and for a total demand of 102 s.f.u. By using subpart 5 curve 
number 2 it is determined that the supply demand in GPM for hot water is 7 and by using the same 
figure but curve 1 it is determined that the demand for cold water in GPM is 67 and the total demand in 
GPM is 68. This breakdown is used in order to size the hot water supply branch, the cold water supply 

branch and the building service line. 

Subp. 7. Exam pie. Assume an apartment building (private type occupancy) having 200 bathroom 
groups with flushometer closets and 200 kitchen sinks. The apartment lawn has installed in it a sprinkler 
system operating from (7) sill cocks. What is the demand flow for which the water service to the apartment 
must be designed? The intermittent use fixtures are figured as in subpart 6 to have a demand of 326 GPM. 



Name of Number on Supply fixture unit value per 

fixture system fixture (Subpart 2) 



Total supply fixture imits 



Bathroom 
group 



300 



Hot 



Cold 



Total 



Hot 



600 



Cold 



1,200 



Total 



1,600 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



300 


300 


400 


900 


1,500 


2,000 


208 


270 


326 



123 PLUMBING CODE 4715.3700 



Kitchen sink 200 1.5 1.5 2 

Total 

Demand in GPM (Subpart 4) 

The lawn sprinkler system outlets have a demand of 5 GPM each, part 4715.1770. The total 
sprinkler system demand is, therefore, 35 GPM. This is added to the total demand (326) of the 
intermittently used fixtures making a total water demand of 361 GPM. This total figure would then be used 
to determine the size of the building service pipe. The 35 GPM demand figure would also be added to the 
cold water demand figure of 270 giving total cold water demand of 305 GPM and this figure would be 

used in sizing the cold water distribution piping. 

Subp. 8. Selection of pipe size.Pipe sizes may be selected according to the following water pipe 
sizing procedure except that in no case shall a pipe size be less than shownin part 4715.1730, subpart 2, nor 
in the case of water service lines, less than specified in part 4715.1710. 

The water pipe sizing procedure is based on a system of pressure requirements and losses, the sum 
of which must not exceed the minimum pressure available at the street main or other source of supply. 

These pressures are expressed as follows: 

A. Pressure required at fixture to produce adequate flow - See part 4715.1770. 

B. Static Pressure loss - This is computed at 0.43 psi per ft of pipe rise or drop and is added or 
subtracted respectively. 

C. Loss through water meter - Pressure or friction losses for various size meters are shown in 
subpart 9 or 10. 

D. Loss through taps in water main - Losses for various size taps are shown in subpart 12. 

E. Losses through special devices such as filters, water softeners, backflow preventers, etc. - 
These must be obtained from the manufacturer, or estimated and added to the total. 

F. Loss through fittings and valves - Losses for these devices are computed by converting the 
fittings or valves to equivalent straight sections of pipe and adding this length to the total for the pipe section 
being considered. Subpart 11 shows equivalent lengths of pipe for fittings and valves. 

G. Loss due to pipe friction - This loss may be readily computed when the pipe size, its length 
and the flow through the pipe are known. When these three factors are known the friction loss can be 
determined from either the tables in subparts 13 and 19 or the figures in subparts 14, 16, 18, and 20. The 
table and the figure used depends on the type of pipe used. An example of this sizing procedure is given in 
subpart 21. 

Subp. 9. Loss of pressure through disk-type meters in pounds per square inch. 

Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 124 



Size of meter 



Gallons 


















per 
minute 


5/8" 


3/4" 


1" 


1-1/2" 


2" 


3" 


4" 


6" 


4 


1.0 
















5 


1.6 
















6 


2.2 
















7 


3.0 


1.1 














8 


4.0 


1.4 














9 


5.0 


1.7 














10 


6.1 


2.1 














15 


14 


5.0 


2.0 












20 




8.8 


3.5 


1.0 










30 




19 


8.0 


2.3 










40 






14 


4.0 


1.6 








50 






22 


6.2 


2.4 








60 








9.0 


3.6 








70 








12 


4.9 


1.3 






80 








16 


6.2 


1.7 






90 








20 


8.0 


2.0 






100 










10 


2.5 


1.0 




120 










14 


3.7 


1.3 




140 










20 


5.1 


2.0 




160 












6.2 


2.4 




180 












8.1 


3.3 




200 












10 


4.0 


1.0 


250 












16 


6.1 


1.7 


300 












23 


9.0 


2.3 


350 














13.0 


3.0 


400 














16.0 


4.0 


500 














25.0 


6.1 


600 
















9.0 


700 
















13 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



125 PLUMBING CODE 4715.3700 

800 16 

900 20 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 



126 



Subp. 10. Graph of loss of pressure through disk-type meters in pounds per square inch. 




U) o m 



Pressure Loss — Lbs/in' 



Subp. 1 1 . Allowance in equivalent length of pipe for friction loss in valves and threaded fittings. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



127 



PLUMBING CODE 4715.3700 









90° 
















side 


Coupling or 




Globe 


Angle 


imeter of 


90° std. 


45° std. 


tee. 


straight run 


Gate valve, 


valve. 


valve. 


ig, inches 


ell, feet 


ell, feet 


feet 


of tee, feet 


feet 


feet 


feet 


3/8 


1 


0.6 


1.5 


0.3 


0.2 


8 


4 


1/2 


2 


1.2 


3 


0.6 


0.4 


15 


8 


3/4 


2.5 


1.5 


4 


0.8 


0.5 


20 


12 


1 


3 


1.8 


5 


0.9 


0.6 


25 


15 


1-1/4 


4 


2.4 


6 


1.2 


0.8 


35 


18 


1-1/2 


5 


3 


7 


1.5 


1.0 


45 


22 


2 


7 


4 


10 


2 


1.3 


55 


28 


2-1/2 


8 


5 


12 


2.5 


1.6 


65 


34 


3 


10 


6 


15 


3 


2 


80 


40 


3-1/2 


12 


7 


18 


3.6 


2.4 


100 


50 


4 


14 


8 


21 


4.0 


2.7 


125 


55 


5 


17 


10 


25 


5 


3.3 


140 


70 


6 


20 


12 


30 


6 


4 


165 


80 



Subp. 12. Loss of pressure through taps and tees in pounds per square inch. 



Gallons 
per minute 



5/8 in. 



3/4 in. 



1 in. 



Size of tap or tee 
1-1/4 in. 1 in. 



2 in. 



3 in. 



10 


1.35 


0.64 


0.18 


0.08 








20 


5.38 


2.54 


0.77 


0.31 


0.14 






30 


12.1 


5.72 


1.62 


0.69 


0.33 


0.10 




40 




10.2 


3.07 


1.23 


0.58 


0.18 




50 




15.9 


4.49 


1.92 


0.91 


0.28 




60 






6.46 


2.76 


1.31 


0.40 




70 






8.79 


3.76 


1.78 


0.55 


0.10 


80 






11.5 


4.90 


2.32 


0.72 


0.13 


90 






14.5 


6.21 


2.94 


0.91 


0.16 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 128 



100 
120 
140 
150 
160 
180 
200 
225 
250 
275 
300 



17.94 


7.67 


3.63 


1.12 


0.21 


25.8 


11.0 


5.23 


1.61 


0.30 


35.2 


15.0 


7.12 


2.20 


0.41 




17.2 


8.16 


2.52 


0.47 




19.6 


9.30 


2.92 


0.54 




24.8 


11.8 


3.62 


0.68 




30.7 


14.5 


4.48 


0.84 




38.8 


18.4 


5.67 


1.06 




47.9 


22.7 


7.00 


1.31 






27.4 


7.70 


1.59 






32.6 


10.1 


1.88 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



129 PLUMBING CODE 4715.3700 



Subp. 13. Pressure loss of water in pounds per square inch per 100 feet of fairly smooth pipe. 



Gallons 3/4" 1" 1-1/4" 1-1/2" 2" 2-1/2" 3" 4" 5" 6" 8" 10" 12" 

per 

minute 

3 1.2 0.37 0.1 

4 2.0 0.61 0.17 

5 3.0 0.95 0.25 0.12 

10 11 3.5 0.9 0.43 0.13 

15 22 7.1 1.8 0.9 0.26 0.11 

20 '39 13 3.0 1.5 0.45 0.18 



25 '58 18 4.7 2.3 0.68 0.28 0.10 

30 - — '25 6.6 3.2 0.93 0.4 0.13 

35 - — '35 8.5 4.3 1.2 0.53 0.18 

40 - — '43 11 5.5 1.6 0.63 0.22 

45 14 6.7 2.0 0.8 0.3 

50 '17 8.1 2.4 1.0 0.35 0.1 

60 '23 12 3.3 1.3 0.5 0.13 

70 '32 '15 4.4 1.8 0.63 0.17 

80 '19 5.7 2.3 0.83 0.23 

90 '24 7.0 2.9 1.1 0.27 

100 '30 8.5 3.7 1.3 0.35 0.12 

150 '17 7.8 2.6 0.7 0.23 

200 '30 '13 '4.5 1.2 0.4 0.16 

250 '18 6.3 1.8 0.59 0.23 

300 '9.0 2.4 0.8 0.34 

350 '13 3.3 1.1 0.45 0.12 - — 

400 '4.2 1.3 0.59 0.15 - — 

450 '5.1 1.7 0.7 0.19 - — 

500 '6.2 2.1 0.85 0.23 - — 

600 '9.0 2.9 1.2 0.32 0.11 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 



130 



700 

800 

900 

1,000 

1,500 

2,000 

2,500 

3,000 

Velocity at or exceeding 10 fps. 



'3.9 1.6 0.43 0.14 - — 

'4.9 2.0 0.56 0.18 - — 

- — '2.5 0.69 0.23 - — 

- — '3.0 0.81 0.28 0.12 

- — '6.5 '1.8 0.59 0.24 

'3.0 0.98 0.4 

'4.5 '1.5 0.61 

'3.0 0.89 



Velocity exceeds 15 fps. 

Subp. 14. Graph of pressure loss of water in pounds per square inch per 100 feet of fairly 
smooth pipe. 

Friction Loh in Head in Lbs. per Sq. In per 100 Ft. Length 
0.1 .2 .3 .4 .5 .6 .8 t 2 3 4 S 6 S 10 20 30 40S0 60 80iOO 




.2 .3 .4 .5 .6 .8 I ,2 3 4 5 (> 8 10 20 30 40 50 60 80100 

Friction Less in Head in Lbs. pet Sq. In per 100 Ft. Lensth 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



131 PLUMBING CODE 4715.3700 



Subp. 15. Pressure loss of water in pounds per square inch per 100 feet of fairly rough pipe. 



Gallons 3/4" 1" 1-1/4" 1-1/2" 2" 2-1/2" 3" 4" 5" 6" 8" 10" 12" 

per 

minute 

3 2.0 0.47 0.17 

4 3.3 0.82 0.30 0.12 

5 5.2 1.3 0.45 0.18 

10 20 4.9 1.7 0.67 0.17 

15 '43 12 3.7 1.4 0.36 0.12 



20 '80 18 6.2 2.5 0.62 0.20 

25 - — '29 9.9 3.9 0.97 0.31 0.13 

30 - — '42 14 5.6 1.3 0.45 0.18 

35 - — '55 18 7.3 1.8 0.60 0.25 

40 - — '70 '24 9.3 2.3 0.75 0.32 

45 '30 12 3.0 0.96 0.42 

50 '37 15 3.7 1.2 0.51 0.12 

60 '52 '21 5.2 1.7 0.70 0.17 

70 '28 7.0 2.2 0.92 0.22 

80 '37 9.0 2.9 1.3 0.29 0.10 

90 '45 12 3.7 1.5 0.36 0.12 

100 '14 4.6 1.8 0.44 0.16 

150 '30 10 4.2 1.0 0.34 0.13 

200 '17 7.0 1.7 0.59 0.23 

250 '26 'll 2.6 0.90 0.35 

300 '15 3.6 1.3 0.50 0.12 - — 

350 '21 4.9 1.7 0.69 0.17 - — 

400 '6.1 2.2 0.88 0.22 - — 

450 '7.6 2.7 1.1 0.27 - — 

500 '9.4 3.3 1.3 0.33 0.11 

600 '13 '4.9 1.8 0.46 0.15 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 



132 



700 

800 

900 

1,000 

1,500 

2,000 

2,500 

3,000 

Velocity at or exceeding 10 fps. 



'6.2 2.5 0.61 0.20 - — 

'8.1 3.3 0.80 0.26 0.11 

'11 '4.1 1.0 0.33 0.13 

M3 



'5.0 


1.25 


0.40 


0.17 


M2 


2.8 


0.90 


0.37 




'4.7 


1.6 


0.63 




'7.2 


'2.4 


1.0 






'3.4 


1.3 



"Velocity exceeds 15 fps. 



Subp. 16. Graph of pressure loss of water in pounds per square inch per 100 feet of fairly rough 



pipe. 



Friction Loii in Head In Lbi. per Sq. In per 100 Ft. Length 
4 K .A H I 2 3 4 5 6 8 10 30 30 40 50 60 SOIOO 




0.1 



.3 .4 .5 .6 .8 1 2 3 4 5 6 8 ID 20 30 40 SO 60 80 IOC 

Friction Losj in Head in Uat. pet Sq, In per 100 Ft. Length 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



133 PLUMBING CODE 4715.3700 



Subp. 17. Pressure loss of water in pounds per square inch per 100 feet of rough pipe. 



Gallons 3/4" 1" 1-1/4" 1-1/2" 2" 2-1/2" 3" 4" 5" 6" 8" 10" 12" 

per 

minute 

3 2.7 0.62 0.20 

4 4.7 1.2 0.36 0.15 

5 6.0 1.4 0.46 0.18 

10 30 7.0 2.3 0.94 0.22 

15 '67 16.0 6.2 2.1 0.49 0.17 

20 - — 27 9.1 3.7 0.89 0.29 0.12 

25 - — '43 14 5.8 1.3 0.45 0.18 

30 - — '62 21 8.5 2.0 0.63 0.27 

35 - — '85 28 12 2.7 0.90 0.36 

40 '37 14 3.5 1.20 0.47 0.12 

45 '47 19 4.5 1.45 0.60 0.14 

50 '58 23 5.5 1.8 0.74 0.18 

60 '83 '33 7.9 2.6 1.10 0.25 

70 '46 12 3.5 1.40 0.35 0.12 

80 '60 14 4.7 1.85 0.45 0.15 



90 '76 18 5.9 2.3 0.58 0.19 

100 '23 7.2 3.0 0.71 0.23 

150 '50 17 6.6 1.7 0.53 0.21 

200 '29 12 2.9 0.95 0.37 

250 '45 '18 4.5 1.49 0.58 0.13 

300 '26 6.4 2.20 0.80 0.19 

350 '36 8.9 2.9 1.20 0.27 

400 '12 3.8 1.45 0.35 0.12 - — 

450 '15 4.7 1.8 0.44 0.14 - — 

500 - '18 6.0 2.3 0.55 0.18 - — 

600 '25 8.3 3.2 0.78 0.26 0.11 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 



134 



700 

800 

900 

1,000 

1,500 

2,000 

2,500 

3,000 

Velocity at or exceeding 10 fps. 



'\2 


4.5 


1.20 


0.36 


0.14 


'\6 


6.0 


1.4 


0.47 


0.19 


'20 


'7.7 


1.8 


0.60 


0.24 




'9.4 


2.3 


0.75 


0.31 




'22 


5.1 


1.7 


0.70 






'9.0 


3.0 


1.25 






'14 


'4.7 


2.0 









'6.8 


2.7 



"Velocity exceeds 15 fps. 

Subp. 18. Pressure loss of water in pounds per square inch per 100 feet of rough pipe. 

Friction LoK in Head in Lb«. per Sq. In per 100 Ft, LcngtK 
.1 .2 .3 .4 .5 .6 .8 I 2 3 4 5 6 8 10 20 30 40 50 60 80100' 




.3 .4 .5 .6 .8 I 2 3 4 5 6 8 10 20 30 40501iO 80100 

Friction Lois in Head in Lbs. pet Sq, In per tOO Ft. LEngt*! 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



135 PLUMBING CODE 4715.3700 



Subp. 19. Pressure loss of water in pounds per square inch per 100 feet of copper pipe. 



Gallons 3/4"' 1"' 1-1/4" 1-1/2" 2" 2-1/2" 3" 4" 5" 6" 8" 10" 12" 

per 

minute 

2 0.84 0.21 

3 1.70 0.42 0.13 

4 2.8 0.69 0.22 0.10 

5 4.2 1.05 0.34 0.15 

6 5.7 1.4 0.47 0.21 

7 7.5 1.8 0.61 0.27 

8 9.6 2.4 0.68 0.33 

9 12 2.8 0.93 0.42 0.12 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 136 



11.5 3.0 

10 14.5 3.5 1.2 0.50 0.14 
18.5 5.2 



'23 6.1 

15 '28 7.1 2.4 1.10 0.27 - — 

'32 8.9 

'37 9.9 

20 '45 12 3.8 1.70 0.44 0.16 

'46 13 

'53 15 

25 '67 '17 5.8 2.5 0.68 0.23 
18 



'21 

30 - — '24 8.0 3.5 0.91 0.32 0.13 
'24 



'27 

35 - — '32 11 4.6 1.25 0.42 0.17 
'30 



'33 

40 - — '38 '13 5.8 1.50 0.52 0.22 
'37 



'43 

45 - — '48 '17 7.1 1.85 0.66 0.28 

50 '19 8.7 2.3 0.79 0.33 

60 '27 12 3.1 1.2 0.46 0.12 

70 '16 4.2 1.4 0.62 0.16 

80 '19 5.2 1.8 0.79 0.20 

90 '24 6.2 2.25 0.96 0.24 

100 '7.6 2.75 1.2 0.30 0.11 - — 

150 '17 '5.8 2.5 0.62 0.22 - — 

200 '9.3 4.1 1.10 0.36 0.15 

250 '14 '6.1 1.60 0.52 0.22 

300 '8.4 2.1 0.72 0.31 

350 '12 2.8 0.98 0.41 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



137 PLUMBING CODE 4715.3700 



400 3.5 



450 '4.3 

500 '5.2 

600 '7.2 



1.25 


0.52 


1.6 


0.63 


1.8 


0.76 


'2.7 


1.15 


'3.4 


1.4 


'4.4 


1.8 


'5.2 


'2.2 




'2.7 



700 

800 ■ 

900 ■ 

1,000 ■ 

For the 3/4" and 1" pipe sizes the three values shown opposite each flow figure are, reading from the top, 
for Types M, L and K copper tubing respectively. 

Velocity at or exceeding 10 fps. 

Velocity exceeds 15 fps. 

Subp. 20. Graph of pressure loss of water in pounds per square inch per 100 feet of copper 
pipe. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 



138 



Friction Lo» in Heod in Lbs. per Sq. In per 1 00 Ft. Length 
.3 .4 .5 .4 .6 I 2 3 4 5 6 8 ID 20 30 40 50 60 80100 




.1 .3 .o .0 I 2 3 4 5 6 8 10 20 30 40 50 60 80100 

Friction Lou in Head in Lbs. per Sq. In per 100 Ft. Length 



Subp. 21. Example. What size copper water pipe, service and distribution will be required to serve 
a two story factory building having on each floor, back-to-back, two toilet rooms each equipped with four 
flushometer closets, two flushometer pedestal urinals and four lavatories with hot and cold water? The 
highest fixture is 21 feet above the street main which is tapped with 2-1/2 inch corporation at which point 
the minimum pressure is 55 psi. In the building basement a two-inch meter and three-inch reduced pressure 
zone backflow preventer with a maximum pressure drop of 9 psi are to be installed. The system is shown by 
the following diagram. To be determined are the pipe sizes for the service main, and the cold and hot water 
distribution pipes. A tabular arrangement such as shown in subpart 10 should first be constructed. The steps 
to be followed in solving the problem are indicated by the table itself as they are in sequence, columns 1 
through 8 and lines a through 1 . 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



139 



PLUMBING CODE 4715.3700 



Subp. 22. Illustration. 
UJ/ 




Subp. 23. Recommended tabular arrangement for use in solving pipe sizing problems. 




Service and 
cold water 



Description 

Minimum pressure available at main 

Highest pressure required at a fixture (part 4715.1770, subpart 2) 

Meter loss 2" meter {subpart 9) 

Tap in main-loss 2-1/2" tap (subpart 12) 



55.00 

15.00 

11.00 

1.29 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3700 PLUMBING CODE 



140 



distribution 


e 


Static head loss 21 x 


143 psi 








9.03 


piping 


f 


Special fixture loss-backflow preventer 






9.00 




g 


Special fixture loss-filter 






0.00 




h 
i 


Special fixture loss-other 

Total overall losses and requirements, sum of lines b through h 


0.00 




45.32 




J 


Pressure available to overcome pipe friction, line a minus sum of 








lines b to 


1 






9.68 












1 


2 


3 


4 


5 


6 


7 


8 




Pipe section 


Gal. per 


Length 


Trial 


Equiva- 


Total 


Friction 


Friction 






min. 


of 


pipe size 


lent 


equiva- 


loss per 


loss in 






through 


section 


(in.) 


length of 


lent 


100' of 


equiva- 






section 


(ft.) 




fittings 


length 


trial size 


lent 






(deter- 






and 


col. 3 


pipe 


length 






mined 






valves 


and col. 


(subpart 


col. 6 






as in 






(subpart 


5 (100 


19) 


X col. 7 






subpart 






11) 


ft.) 




(psi) 






3) 
















AB 


107 


54 


2-1/2 


12.8 


0.67 


3.0 


2.00 




EC 


101 


8 


2-1/2 


8 


0.16 


2.8 


0.45 




CF 


76 


150 


2-1/2 


1.6 


1.52 


1.7 


2.58 




CD 


76 


13 


2-1/2 


8 


0.21 


1.7 


0.36 




DE 


76 


150 


2-1/2 


1.6 


1.52 


1.7 


2.58 






k 


Total pipe friction losses (cold) 7.97 psi 






7.97 




1 


Difference line i mini 


IS line k 






1.71 






■' 

















Hot Water Distribution Piping 








AB' 

B'C 


107 
37 
28 
28 
28 


54 

8 

150 

13 
150 


2-1/2 

2 

2 

1-1/2 

1-1/2 


12.8 
15.3 

1.3 
5 

1.0 


0.67 
0.23 
1.51 
0.18 
1.51 


3.0 
1.2 
0.8 

3.2 
3.2 


2.00 
0.22 
1.21 
0.58 
4.84 




CF' 




CD' 




D'E' 










k 
1 


Total pipe friction los 
Difference line i mini 


ses (hot) 8.85 psi 

IS line k 






8.85 
0.83 






■' 











Subp. 24. Directions for constructing tabular arrangement. Step 1, column 1: divide the system 
into sections breaking at major changes in elevation or where branches lead to fixture groups. After point 
(B) (see sketch in subpart 22) separate consideration will be given to the hot and cold water piping. Enter 
the sections to be considered in the service and cold water piping in column 1 of the tabular arrangement. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



141 PLUMBING CODE 4715.3700 

Column 3: According to the method given in subpart 3 determine the GPM of flow to be expected 
in each section of the system. These flows range from 28 to 107 GPM. 

Step 2, line a: enter the minimum pressure available at the main source of supply. This is 55 psi. 

Line b: determine from part 4715.1770, subpart 2 the highest pressure required for the fixtures on 
the system, which is 15 psi to operate a flushometer valve. 

Line c: select from subpart 9 the pressure loss for the meter size given or assumed. The total water 
flow from the main through the service as determined in step 1 will serve to aid in the meter selected. 

Line d: select from subpart 12 and enter the pressure loss for the tap size given or assumed. 

Line e - Determine the difference in elevation between the main or source of supply and the 
highest fixture on the system and multiply this figure, expressed in feet, by 0.43 psi. Enter the resulting 
psi product on line e. 

Line f, g, h: the pressure losses through filters, backflow preventers, or other special fixtures must 
be obtained from the manufacturer or estimated and entered on these lines. 

Step 4, line i: the sum of (lines b through h) the pressure requirements and losses which affect the 
overall system is entered on this line. 

Step 5, line j: subtract line i from line a. This gives the pressure which remains available for 
overcoming friction losses in the system. This figure is a guide to the pipe size which is chosen for each 
section as the total friction losses through all the sections should not exceed this value. 

Step 6, column 3: enter the length of each section. 

Step 7, column 4: select a trial pipe size. A rule of thumb is that size will become progressively 
smaller as the system extends farther from the main or source of supply. 

Step 8, column 5: select from subpart 11 the equivalent lengths for the trial pipe size of fittings 
and valves on the section. Enter the sum for each section in column 5. {The number of fittings to be used 
in the installation of this piping must be an engineering estimate.) 

Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3800 PLUMBING CODE 142 

Step 9, column 6: add the figures from column 3 and column 5, and enter in column 6. Express 
the sum in hundreds of feet. 

Step 10, column 7: select from subpart 19 the friction loss per 100 feet of pipe for the GPM flow in 
a section (column 2) and the trial pipe size (column 4). 

Step 11, column 8: multiply the figures in columns 6 and 7 for each section and enter in column 8. 

Step 12, line k: enter the sum of the values in column 8. 

Step 13, line 1: subtract line k from line j. The result should always be a positive or plus figure. If it 
is not, it is necessary to repeat the operation utilizing columns 4, 5, 7 and 8 until a balance or near balance 
is obtained. If the difference between lines j and k is positive and large, it is an indication that the pipe 
sizes are too large and may, therefore, be reduced thus saving materials. In such a case the operations 
utilizing columns 4, 5, 7, and 8 should again be repeated. 

Answer: the final figures entered in column 4 become the design pipe size for the respective 

sections. Repeating this operation a second time using the same sketch but considering the demand for 

hot water, it is possible to size the hot water distribution piping. This has been worked up as a part of the 

overall problem in the tabular arrangement used for sizing the service and cold water distribution piping. It 

should be noted that consideration must be given the pressure losses from the street main to the water 

heater (section AB) in determining the hot water pipe sizes. 
Statutory Authority: MS s 16B.62; 326.37 to 326.45 
History: 19 SR 590 
Posted: July 31, 2007 

4715.3800 RECOMMENDED GUIDE FOR SIZING WATER SUPPLY SYSTEM. 

Subpart 1 . Conditions to be determined. On any proposed water piping installation sized pursuant 
to subpart 9, the following conditions shall be determined: 

A. Total number of fixture units as determined from the table of equivalent fixture units (subpart 
8) for the fixtures to be installed. 

B. Developed length of supply pipe from meter to most remote outlet, or if the pressure at the 
meter is unknown, use the developed length from the street main to most remote outlet. 

Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



143 PLUMBING CODE 4715.3800 



C. Difference in elevation between the meter or other source of supply and the highest fixture 
or outlet. 

D. Pressure in the street main or other source of supply at the locality where the installation is 
to be made. Calcidations shall be based on not to exceed 100 psi pressure in the system. 

E. In localities where there is a wide fluctuation of pressure in the main throughout the day, the 
water piping systems shall be designed on the basis of the minimum pressure available. 

Subp. 2. Size of street service, meter and building supply pipe using subpart 9. Knowing the 
available pressure at the water meter, water main, or other source of supply, and after subtracting one-half 
pound per square inch pressure for each foot of difference in elevation between such source of supply and 
the highest water supply outlet in the building or on the premises, use the "pressure range" group within 
which this pressure will fall. Select the "length" column which is equal to or longer than the required length. 
Follow down the column to a fixture unit value equal to or greater than the total number of fixture units 
required by the installation. Having located the proper fixture unit value for the required length, sizes of 
meter and building supply pipe will be found in the two left-hand columns. 

Subp. 3. Size of branches. The size of each branch shall be determined by the number of fixture 
units to be served by that branch, following the methods in subpart 2. 

Subp. 4. Sizing for flushometer valves. Branches and mains serving water closet or similar 
flushometer valves may be sized from subpart 9 when the following values are assigned to each flushometer 
valve beginning with the most remote valve on each branch: 

A. for the first flushometer valve, 40 fixture units; 

B. for the second flushometer valve, 30 fixture units; 

C. for the third flushometer valve, 20 fixture units; 

D. for the fourth flushometer valve, 15 fixture units; and 

E. for the fifth flushometer valve, ten fixture units. 

After the fifth valve on any branch, subsequent loadings may be computed using the values given in 

subpart 8 of this chapter. Piping supplying a flushometer valve shall not be less in size than the valve inlet. 

Subp. 5. Hot water sizing. In sizing the hot water piping or water supply systems from subpart 9, 
the greatest developed length of the cold water supply piping may be used and the length of the hot water 
piping ignored when the hot water piping friction loss is compensated for by the following method: 

A. Compute the total hot water fixture unit demand, using those values given in subpart 8 for 
the combined hot and cold water use. 

B. Assign the total demand computed as required in item A, as the fixture unit demand at the 
hot water heater supply branch and inlet. 

Subp. 6. Cold water piping. Starting at the most remote outlet on the cold water piping and working 
back toward the water meter, compute the pipe sizing for the system from the column originally selected in 
subpart 9, using the fixture unit values given in subpart 8, and adding in the fixture unit demand of the hot 
water heater supply inlet as computed in subpart 5, at the point where it occurs. The final size of the cold 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3800 PLUMBING CODE 



144 



water main need not be larger than the originally established size required by subpart 9 for the total building 
supply. 

Subp. 7. Hot water piping. Starting at the most remote outlets on the hot water piping and working 
back toward the water heater, compute the pipe sizing for the system from the column originally selected in 
subpart 9, using the fixture unit values given in subpart 8. 

Subp. 8. Equivalent fixture units, including combined hot and cold water demand. 



Fixture 

Bar sink 

Bathtub {with or without shower over) 

Dental unit or cuspidor 

Drinking fountain (each head) 

Hose Bibb of sill cock (standard type) 

House trailer (each) 

Laundry tub or clothes washer (each pair of faucets) 

Service sink 

Lavatory 

Lavatory (dental) 

Lawn sprinklers (standard type, each head) 

Shower (each head) 

Sink (bar) 

Sink or dishwasher 

Sink (flushing rim, clinic) 

Sink (washup, each set of faucets) 

Sink (washup, circular spray) 

Urinal (pedestal or similar type) 

Urinal (stall) 

Urinal (wall) 

Urinal (flush tank) 

Water closet (flush tank) 

Water closet (flushometer valve) 



Number of 


Fixture Unit 


Private Use 


Public Use 


1 


2 


2 


4 


- 


1 


- 


1 


3 


5 


6 


6 


2 


4 


- 


4 


1 


2 


1 


1 


1 


1 


2 


4 


1 


2 


2 


4 


- 


10 


- 


2 


- 


4 


- 


10 


- 


5 


- 


5 


- 


3 


3 


5 


_ 


10 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



145 PLUMBING CODE 4715.3800 



Water supply outlets for items not listed above shall be computed at their maximum demand, but in no 
case less than: 



3/8 inch 1 2 

1/2 inch 2 4 

3/4 inch 3 6 

1 inch 6 10 

* See subpart 4 for method of sizing flushometer valve installations using this subpart. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.3800 PLUMBING CODE 



146 



Subp. 9. Fixture unit table for determining water pipe and meter sizes for water supply systems. 

PreSBure Range — 30 to 45 pel 



Meter & 


Building 






Maximum Allowable Length in Feet 






Street 


Supply & 
BraacheB 






















Service 


























40 


60 


80 


100 


150 


200 


250 


300 


400 


500 


H' 


3^' 


6 


6 


4 


4 


3 


2 














H' 


1^' 


IS 


16 


14 


12 


9 


6 


— 


— 


— 


— 


%' 


29 


26 


23 


21 


17 


15 


13 


12 


10 


9 


1* 


1' 


86 


31 


27 


25 


20 


17 


IB 


13 


12 


10 


1* 


IH' 


64 


47 


42 


88 


32 


28 


26 


23 


19 


17 


!«' 




90 


68 


67 


48 


38 


82 


28 


25 


21 


19 


IJ^' 


151 


124 


105 


91 


70 


57 


49 


46 


86 


81 


2* 


IH' 


210 


162 


132 


110 


80 


64 


63 


46 


88 


32 


W 


2' 


220 


205 


190 


176 


155 


138 


127 


120 


105 


96 


2* 


872 


329 


292 


265 


217 


185 


164 


147 


124 


107 


2' 


2K' 


445 


418 


390 


370 


330 


800 


280 


266 


240 


220 



PreHsure Range — 46 to 60 pei 



H' 


W 


9 


8 


7 


6 


5 


4 


3 


2 






:^- 


%' 


27 


23 


19 


17 


14 


11 


9 


8 


6 


S 


!'■ 


44 


40 


36 


33 


28 


23 


21 


19 


17 


14 


1' 


60 


47 


41 


86 


80 


25 


23 


20 


18 


16 


!• 


IH' 


102 


87 


76 


67 


52 


44 


39 


36 


SO 


27 


\H' 


IH' 


168 


130 


106 


89 


66 


52 


44 


39 


33 


29 


. IH* 


IH* 


270 


225 


193 


167 


128 


105 


90 


68 


62 


62 


2* 


^'A' 


860 


290 


242 


204 


150 


117 


98 


84 


67 


55 


IH' 


2' 


880 


860 


840 


318 


272 


240 


220 


198 


170 


146 


2* 


2' 


570 


6X0 


470 


430 


868 


318 


280 


250 


205 


173 


2- 


2H' 


680 


640 


610 


580 


535 


600 


470 


440 


400 


866 



PresBure Range — Otst 60 pd 



H' 


yi' 


11 


9 


8 


7 


6 


6 


4 


3 


2 




M* 


1^' 


84 


28 


24 


22 


17 


13 


11 


10 


8 


— 


r 


63 


53 


47 


42 


85 


SO 


27 


24 


21 


18 


1* 


87 


66 


65 


48 


88 


32 


29 


26 


22 


19 


1" 


1 ii' 


140 


126 


108 


96 


74 


62 


53 


47 


89 


84 


IH' 




237 


183 


150 


127 


93 


74 


62 


64 


43 


87 


W 


IJ^' 


366 


811 


273 


240 


186 


154 


130 


113 


88 


78 


li^- 


490 


395 


333 


275 


220 


170 


142 


122 


98 


82 


li"' 


•380 


•380 


•380 


•380 


870 


835 


305 


282 


244 


212 


2* 


•690 


670 


610 


660 


478 


420 


375 


340 


288 


245 


2' 


2>S' 


•690 


•690 


♦690 


•690 


•690 


650 


610 


670 


510 


460 



•Maximum Allowable Load on M«ter. 



Subp. 10. [Repealed, 28 SR 146] 

Subp. 10a. Example of cold water sizing using subpart 9. 



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147 



PLUMBING CODE 4715.3800 






S 




e 




ss 




■-3 




t«s 


41 


Ui 


=iaa 




3 ° 


»- rjCN 






r^^ 




£S S 














J « * '^ 
















= if ;- O 


"f nlPJ 


««oK 



Subp. 11. [Repealed, 28 SR 146] 

Subp. 11a. Example of hot water sizing using subpart 9. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.4100 PLUMBING CODE 



148 




Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326.37 to 326.45 
History: 28 SR 146 
Posted: July 31, 2007 

4715.3900 [Repealed, 15 SR 76] 
Posted: July 31, 2007 

4715.4000 [Repealed, 15 SR 76] 
Posted: July 31, 2007 

4715.4100 USEFUL INFORMATION. 
Subpart 1. Weights and measures. 

Commercial Weights 



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149 PLUMBING CODE 4715.4100 



16 drams or 437.5 grains = 1 ounce 

16 ounces or 7000 grains = 1 pound 

16 ounces = 1 pound 

2000 pounds = 1 ton 



Square Measure 



144 square inches = 1 sq. foot 

9 square feet = 1 sq. yard 

30 1/4 square yards = 1 sq. rod 

272 1/4 square feet = 1 sq. rod 

43,560 square feet = 1 acre 



Cubic Measure 



231 cubic inches = 1 gallon 
1728 cubic inches = 1 cu. ft. 
27 cubic feet = 1 cu. yd. 



Long Measure 



12 inches = 1 foot 

3 feet = 1 yard 

16 1/2 feet = 1 rod 

320 rods = 1 mile 

5280 feet = 1 mile 



Liquid Measure 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.4100 PLUMBING CODE 150 

4 gills = 1 pint 

2 pints = 1 quart 

4 quarts = 1 gallon 

31 1/2 gallons = 1 U.S. barrel 

Water Pressure 

To find the pressure in pounds per square inch corresponding to any head in feet, multiply the 
head by 0.434. 

To find the head in feet when the pressure in pounds per square inch is known, multiply the 
pressure by 2.3. 

One pound pressure per square inch is caused by 2.3 feet head of water. 

Subp. 2. Pressure and head equivalents. Table based on water at 62.5 pounds per cubic foot. 





Pressure 


(pounds per 




Pressure (pounds per 


Head (feet) 


square inch) 


Head (feet) 


square inch) 


2.304 




1 


1 


0.434 


4.608 




2 


2 


0.868 


6.912 




3 


3 


1.302 


9.216 




4 


4 


1.736 


11.520 




5 


5 


2.170 


13.824 




6 


6 


2.604 


16.128 




7 


7 


3.038 


18.432 




8 


8 


3.472 


20.736 




9 


9 


3.906 


23.040 




10 


10 


4.340 



Subp. 3. Water pressure. Example: What pressure in pounds per square inch corresponds to a head 
of 123'-6"? 



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151 PLUMBING CODE 4715.4100 

123'-6" = 123.5' (See table IE) 
From table I (right half) 



120' = 12x10 = 12x4.34 = 52.08 
3' = 1x3 = 1x1.302 = 1.302 

.5' = .5x1 = .5X.434 = .217 



53.599 Ibs/sq. in. (Ans.) 

Example: How many feet of head is equivalent to a pressure of 28 pounds per square inch? 
From table I (left half) 



20 = 10x2 = 10x4.608 = 46.08 

8 = 1x8 = 1x18.432 = 18.432 



64.512' or 64'-6" (Ans.) 



Subp. 4. Effect of variations of temperatures on water. Water freezes at 32 degrees Fahrenheit. 
Water boils at 212 degrees Fahrenheit. Water expands when freezing to about one and one-twelfth of its 
bulk. Fifteen hundred and ninety-five cubic inches of water will expand in freezing to one cubic foot of ice, 
which weighs approximately 57.5 pounds. 

Water freezing in a pipe or closed vessel exerts a pressure of approximately 2,000 pounds per square 

inch which is the force that causes pipes to burst. 

Subp. 5. Changing common fractions into decimals. In several computations used in plumbing 
work it is desirable to convert fractions into decimals and decimals into fractions in order to facilitate 
computations and measurements. 

A. Example: Change 1/8 to decimals of an inch. 



1/8 = 8)1.000 = .125 (Ans.) 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.4100 PLUMBING CODE 



152 



B. Example: Change .3125 to closest 1/16 of an inch. 



1/16 = .0625 
.0625).3125 = 



5 hence 5/16 (Ans.) 



C. Example: Change 2" into decimals of a foot. 



2" = 2/12 = 2x1/12 = 2X.08333 = .16667 (Ans.) 



Subp. 6. Decimal equivalents of common fractions in inches. 



Fraction Decimal 

1/32... 0.03125 

1/16 0625 

3/32... .09375 
1/8 125 

5/32... .15625 

3/16 1875 

7/32... .21875 
1/4 25 

9/32... .28125 

5/16 3125 

11/32... .34375 
3/8 375 

13/32... .40625 

7/16 4375 

15/32... .46875 
1/2 5 



Fraction Decimal 

17/32... 0.53125 

9/16 5625 

19/32... .59375 
5/8 625 

21/32... .65625 

11/16 6875 

23/32... .71875 
3/4 75 

25/32... .78125 
13/16 8125 

27/32... .84375 
7/8 875 

29/32... .90625 

15/16 9375 

31/32... .96875 
1 1.0 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



153 



PLUMBING CODE 4715.4100 



Subp. 7. Decimal equivalents of inches in feet. 



Inches Decimal 



1 


0.08333 


2 


0.16667 


3 


0.25000 


4 


0.33333 


5 


0.41667 


6 


0.5000 


7 


0.58331 


8 


0.66667 


9 


0.75 


10 


0.83333 


11 


0.91666 


12 


1.00 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.4100 PLUMBING CODE 



154 



Subp. 8. Geometric calculations. 
Fig. I3C 




CIRCLE 
D= Diometer r= Radius 
w~ CircuiTiisr6nCc 
Area= 3.l4l6x r' 
AreQ= 0.7854x0* 
C= 5.1416 X D 
D= 0.3I83IXC 



SPHERE 
Volume = 0.5236x0* 






I/. 



<^ 



T 

H 



auuMnc. un UDLUnia lANK 



Volume^ AxBxC 



rvi iNnpir.Ai TAWh- 



Volume^ 0.7854X iAh 



Subp. 9. Diameter, area, circumference, and volume. 



Diameter 




(inches) 


Area (sq. inch) 


1/2 


0.19635 


5/8 


0.30680 


3/4 


0.44179 


1 


0.7854 


1 1/4 


1.22719 


1 1/2 


1.76715 


2 


3.1416 


2 1/2 


4.90875 


3 


7.0686 


4 


12.5664 


5 


19.6350 


6 


28.2744 


8 


50.2656 



Circumference (inches) 

1.5708 
1.9635 
2.3562 
3.1416 
3.9270 
4.71240 
6.2832 
7.8540 
9.4248 
12.5664 
15.7080 
18.8496 
25.1328 



Volume (gal. per ft.) 

0.010 

.016 

.023 

.041 

.064 

.092 

.163 

.255 

.367 

.652 
1.020 
1.470 
2.610 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



155 



PLUMBING CODE 4715.4100 



10 
12 



78.5400 
113.0976 



31.4160 

37.6992 



4.080 
5.870 



A. Example: 



(A = Pi/4xD') 



What is the area of a pipe in square inches having a diameter of 
six inches? 



A = 0.7854xD' 
A = 0.7854x6x6 = 



28.27 sq. in. (Ans.) 



B. Example: 
(D = Cxl/Pi) 



What is the diameter in inches of a pipe having a circumference 
of approximately 15-3/4 inches? 

D = CxO. 31831 

D = 15.75x0.31831 = 5 inches (Ans.) 



C. Example: 



What is the volume of a tank in cubic feet and gallons having a 
length of eight feet, a width of four feet, and a depth of six feet? 



V = 8'x4'x6' = 192 cubic feet (Ans.) 



V = 



1 cu. ft. = 7 1/2 gallons 
192x7.5 = 1440 gallons (Ans.) 



D. Example: 



What is the volume of a tank in cubic feet and gallons having a 
diameter of 18 inches and a height of 4 feet? 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.4100 PLUMBING CODE 156 



V = 0.7854xD'xH 



= 0.7854x1. 5'xl.5'x4' = 7.0686 cubic feet (Ans.) 



V = 7.0686 = 53.01 gallons (Ans.) 



Doubling the diameter of a pipe increases its area four times. 
Doubling the diameter of a pipe increases its volume four times per unit of length. 
The side of a square equal in area to a given circle equals diameter x 0.8862. 
A gallon of water (U.S. standard) weighs 8-1/3 lbs. 
A cubic foot of water contains 7-1/2 gallons, 1728 cubic inches and weighs 62-1/2 pounds. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



157 



PLUMBING CODE 4715.4100 



Subp. 10. Illustration of measurements. 

Fig! Flg.n 






C<. /N/ 



/V)C J\ 



Jb / /N.V 
^•.N / / /- 
k'* / / / 

^" / . / _6.*' 

-f-- / / X X'i^N^ 

N* / / / .. V O 
A* / / / o"^<^ 
^'•' / ,' / J^o* 






/ / .' / -<y, 
- ./ / / / ^^^ 



>x , ' / *v " 



r ys, y cF>.<ir 
/ y \/ •-*^ 

~ :a*; \" 
l\ 
I 

1 

When pipes are offset, the length of the connecting pipe may 
be figured, when the anqie of the fittings is known and one of 
the the diniensrons A, B, or C is known. 



Fig.m 
FACTORS 

C- A w I yt I yx n 
- " A i.-r 1 -T t. 

a=Sx .41 



\ I 



/ 



/ 



/ 



/ 



/ 



/ 



\ 



/ 



T 

i— > 



-> t 



-A *• 



Subp. 11. Pipe fitting angle calculations. 



Fittings 



B 



1/64 bend 



5-5/8 degrees A = Cx.098 



B = Cx.9952 



C = Bxl.005 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.4100 PLUMBING CODE 158 

A = Bx.0985 B = Axl0.1532 C = AxlO.204 

1/32 bend 11-1/4 degrees A = Cx.l95 B = Cx.981 C = Bxl.019 

A = Bx.l989 B = Ax5.0273 C = Ax5.1258 

1/16 bend 22-1/2 degrees A = Cx.3827 B = Cx.9239 C = Bxl.0823 

A = Bx.4142 B = Ax2.4142 C = Ax2.6131 

1/12 bend 30 degrees A = Cx.5 B = Cx.866 C = Bxl.l547 

A = Bx.5774 B = Axl.7321 C = Ax2.00 

1/8 bend 45 degrees A = Cx.7071 B = Cx.7071 C = Bxl.4142 

A = B B = A C = Axl.4142 

1/6 bend 60 degrees A = Cx.866 B = Cx.5 C = Bx2.0 

A = Bxl.732 B = Ax.5774 C = Axl.l547 

3/16 bend 67-1/2 degrees A = Cx.9239 B = Cx.3827 C = Bx2.6131 

A = Bx2.4142 B = Ax.4142 C = Axl.0923 

1/5 bend 72 degrees A = Cx.951 B = Cx.309 C = Bx.324 

A = Bx3.0777 B = Ax.325 C = Axl.0514 

When the figures from this table are used, it will be necessary to allow for the distance taken up by the 
fittings. (See Fig. II, in subpart 10.) 

Examples; 



A. What is the length of pipe center to center of 45 degree elbows, with an offset 
of 22 inches? 



From table V under 45 degree fittings 



C = Axl.4142 

C = 22x1.4142 = 31.1124 inches 

31.1124' = 2' 7-1/8" (Ans.) 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



159 PLUMBING CODE 4715.5100 



B. What is the length of pipe center to center of 60 degree fittings, with an offset 
of 2' 8"? 



From table V under 60 degree fittings 



C = Axl.1547 

C = 32x1.1547 = 36.9504 inches 

36.9504" = 3' 15/16" (Ans.) 



Statutory Authority: MS s 326.37 to 326.45 
Posted: July 31, 2007 

WATER CONDITIONING CONTRACTORS AND INSTALLERS 

4715.5000 SCOPE AND APPLICABILITY. 

Parts 4715.5000 to 4715.6000 prescribe minimum standards and procedures for all water conditioning 
installations and servicing in single-family dwellings. Any person who installs or services water 
conditioning equipment, whether or not such person is licensed pursuant to Minnesota Statutes 1978, 
sections 328.57 to 328.66, must comply with the standards and procedures prescribed in parts 4715.5000 
to 4715.6000, and with the applicable provisions of the current version of the Minnesota Plumbing Code, 
parts 4715.0100 to 4715.2860. 

Statutory Authority: MS s 326.60 

Posted: July 31, 2007 

4715.5100 DEFINITIONS. 

Subpart 1. Commissioner. "Commissioner" means the commissioner of health. 

Subp. 2. Disinfect. "Disinfect" means to destroy pathogenic bacteria and other harmful organisms. 

Subp. 3. Installation. "Installation" as defined in Minnesota Statutes 1978, section 326.61, 
subdivision 1 includes: 

A. the connection of any water conditioning equipment to an existing water distribution system; 

B. the connection of the line carrying conditioned water to a water distribution system, or raw 
water to points not needing conditioned water; 

C. the connecting of drain and overflow lines which drain the equipment; and 

D. the providing of an air gap between the drain and overflow lines and the receiving building 
receptor. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.5300 PLUMBING CODE 160 



Subp. 4. Raw water. "Rawwater"means water which has not passed through any water conditioning 
equipment. 

Subp. 5. Receptor. "Receptor" means an open, accessible, indi\ddual waste sink, floor drain, or other 
fixture which is trapped and vented in accordance with the Minnesota Plumbing Code (parts 4715.0100 to 
4715.2860). 

Subp. 6. Servicing. "Servicing" means repairs or adjustments to any water conditioning 
installations. 

Subp. 7. Water conditioning contractor. "Water conditioning contractor" means the person in a 
firm or corporation who has demonstrated skill in planning, superintending, installing, and servicing water 
conditioning installations. 

Subp. 8. Water conditioning equipment. "Water conditioning equipment" (equipment) means 
any appliance, appurtenance, or fixture designed to treat water, so as to alter, modify, add, or remove any 
minerals, chemicals, or bacteria contained in water 

Subp. 9. Water conditioning installer. "Water conditioning installer" means a person, other than a 
water conditioning contractor, who has demonstrated practical knowledge of water conditioning installation 
and servicing. 

Subp. 10. Water distribution system. "Water distribution system" means a water supply system as 
defined in the Minnesota Plumbing Code (part 4715.0100). 

Statutory Authority: MS s 326.60 

Posted: July 31, 2007 

4715.5200 CONNECTION WITH WATER DISTRIBUTION SYSTEM. 

Any water conditioning equipment may be installed only in connection with a water distribution system 
which has already been constructed. Such connection may be made either by cutting into a cold water line 
or by connecting to a joint specifically installed for the purpose. In connecting the equipment the contractor 
or installer may use only the type of pipe material which is permitted in the Minnesota Plumbing Code (parts 
4715.0100 to 4715.2860). 

Every installation shall include the installation of a bypass valve which would allow the equipment 
to be ser\dced or removed without the need for shutting off the water service completely. 

If the homeowner so requests, the installer or contractor is permitted to install a line which bypasses 
the water conditioning equipment and to connect this raw water line to any existing service outlet. 

Statutory Authority: MS s 326.60 

Posted: July 31, 2007 

4715.5300 EQUIPMENT DRAIN. 

The equipment drain line shall drain into the existing receptor such as a floor drain or laundry tub. No 
drain or overflow line leading from the equipment shall be directly connected to any receptor. Between the 
delivery end of the drain or overflow line and the receptor, there must be an air gap which is at least two 
times the diameter of the drain or overflow line, but in no case shall the air gap be less than 1.5 inches. This 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



161 PLUMBING CODE 



air gap distance shall apply above the flood level rim of the receiving fixture to pro\dde the required air gap. 
If flexible drain line is used, it must be secured in some manner to prevent its being accidentally moved. 

Statutory Authority: MS s 326.60 

Posted: July 31, 2007 

4715.5400 LOCATION. 

Any water conditioning equipment and the piping necessary to install such equipment shall not be 
placed in such a location or manner so as to interfere with the normal operation of existing windows, doors, 
or other exits or openings, nor shall it be located in such a place so as to make other existing equipment 
inaccessible. 

Statutory Authority: MS s 326.60 

Posted: July 31, 2007 

4715.5500 REGENERATION SANITATION PROCEDURES. 

All new or used water conditioning equipment shall be disinfected before being installed. All portable 
exchange water conditioning equipment shall be disinfected during every regeneration. Disinfection shall 
be achieved by the application of chlorine or a chlorine compound such as sodium or calcium hypochlorite, 
during the fresh water rinse, to provide an effluent minimum chlorine residual and time combination as given 
in the following table: 



Minimum Time 

Minutes Minimum Chlorine Residual - parts per million 

4 20 

5 15 
10 7.5 
15 5.0 
20 4.0 

Statutory Authority: MS s 326.60 
Posted: July 31, 2007 

4715.5600 [Repealed, L 2007 c 140 art 13 s 3] 
Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



4715.5800 PLUMBING CODE 162 



4715.5700 EQUIPMENT AND MATERIALS USED IN INSTALLATIONS. 

Where applicable, the following shall conform to the Minnesota Plumbing Code (parts 4715.0100 
to 4715.2860): all materials and connections used in the installation of water conditioning and treatment 
equipment; all attachments to the building. 

In accordance with the Minnesota Plumbing Code (parts 4715.0100 to 4715.2860): 

A. the bypass valve assembly shall be the same size as the line in which it is installed and shall 
be a full-way valve unless abypass valve which complies with part 4715.5200 is supplied as an integral part 

of the water conditioning equipment; 

B. joints and connections which are made in the course of installing water conditioning and 
treatment equipment shall be tested for water tightness; 

C. copper tube joints shall be soldered or brazed; 

D. soft copper tubing joints may be flared or soldered; 

E. vertical piping shall be secured at sufficiently close intervals to keep the pipe in alignment 
and carry the weight of the pipe; and 

F. horizontal piping shall be supported at sufficiently close intervals to keep it in alignment and 
prevent sagging. 

Statutory Authority: MS s 326.60 

Posted: July 31, 2007 

4715.5800 LICENSING. 

Subpart 1. Examination. A written examination for the licensing of water conditioning equipment 
contractors and installers shall be given at least once per year. The licensing examination for contractors and 
installers shall include questions covering one or more of the following subject areas: relevant plumbing 
and installation provisions, materials and tools of the trade, general principles of water conditioning 
processes, and operation of water conditioning equipment. In addition to the above, the contractor's 
licensing examination shall include questions covering one or more of the following subjects: calculations 
to determine appropriate equipment size, and specific functions and processes involved in different types 
of water conditioning. 

Subp. 2. Examination requirements for installers. The examination for the installer's license shall 
be given only to persons who have had at least six months' experience in the field of water conditioning 
installation and servicing. 

Subp. 3. Contractor's license requirement. The examination for the contractor's license shall 
be given only to persons who have had at least 12 months' experience in planning and supervising the 
installation and servicing of water conditioning equipment. 

Subp. 4. Application. A person applying to take an examination shall complete an application 
supplied by the Minnesota Department of Health and return the completed application along with the 
appropriate examination fee. 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved. 



163 PLUMBING CODE 4715.6000 

Subp. 5. Results of the examination and license. A grade of 70 percent shall be considered a 
passing grade. The applicant shall be notified of the results of the examination. A license shall be issued to 
an applicant who has passed the examination upon receipt of the appropriate license fee. 

Statutory Authority: MS s 326.60 

Posted: July 31, 2007 

4715.5900 [Repealed, L 2007 c 140 art 13 s 3] 

Posted: July 31, 2007 

4715.6000 RENEWAL. 

A license expires on December 31 of the year for wliich it was issued. An application for renewal of 
a license must be received by the Minnesota Department of Health no later than December 31. Any person 
who submits an application for license renewal after December 31 must pay a penalty of $25 in addition 
to the annual license fee. A person who does not renew a license issued pursuant to parts 4715.5000 to 
4715.6000, within two years of the date on which the former license expired, is no longer entitled to a 
renewal license. The person must apply for reexamination and a new license. 

Statutory Authority: MS s 16A.128; 16AJ285; 144.12; 326.37 to 326.45; 326.57 to 326.65 

History: 18 SR 1519 

Posted: July 31, 2007 



Copyright ©2007-2008 by tlie Revisor of Statutes, State of Minnesota. All Rights Reserved.