Plumbing Amendments

Department of Administration Adopted Permanent Rules Relating to Plumbing Code 4715.0100 DEFINITIONS.

For text of subpart 1, see M.R.

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 knowledgeable 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 government, 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.)

For text of subps 3 to 128, see M.R.

4715.0420 STANDARDS FOR PLUMBING MATERIALS.

For text of subpart 1, see M.R.

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

For text of items A to F, see M.R.

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 FITTINGSA21.2A21.6 A74 WWP401C CS188

1A Cast Iron Pipeand Fittings A21.8Extra Heavy

1B Cast Iron PipeCentrifugallyCast Only andFittings A21.6 A74 WWP401C CS188Service Weight A21.8

1C Cast IronMechanical A21.11(Gland Type)Pipe A21.2 WWP421aA21.6

1D Cast IronMechanical A21.8(Gland Type)PipeCement Lined A21.4A21.2A21.6A21.8

1E Cast IronShort BodyWater ServiceFittings(2"12") A21.10 AWWA C100

1F Cast IronThreaded Pipe A40.5

1G High SiliconPipe, FittingsCast Iron

1H Cast IronThreadedFittings B16.4 WWP501Black andGalvanized125#

1J Cast IronDrainageFittings B16.12 WWP491Black andGalvanized

1K Hubless CastIron Pipe and CISPIFittings Standard30169TCSA/CAN 3B70

1L Ductile IronPipe Flanged A21.15 AWWA C115

1M Ductile IronPipe RubberGasket Joints A21.51 AWWA C151

II. STEEL AND WROUGHT IRON PIPE FITTINGS

2A Steel Pipe,Welded andSeamlessGalvanized,Schedule 40and Above B36.1 A53B36.20 WWP4066(1)

2B Wrought IronPipe,Galvanized B36.2Schedule 40and Above

2C(a) StainlessSteel Pipe B36.19

2C(b) StainlessSteel Pipe A112.3.1

2D GalvanizedMalleableFittings B16.3 A197150 psi andAbove

2E Steel Unions,Galvanized WWV531 C

III. COPPER AND COPPER BASE PIPE AND FITTINGS

3A Red Brass Pipe,Regular andHeavier H27.1 B42B

3B Seamless BrassTube H36.1

3C Brass or BronzeThreadedFittings 125lbs. and Over B16.15 B62 WWP460

3D Brass or BronzeFlare Fittings125 lbs. andOver, HeavyDuty LongCollar Type B62

3E Seamless CopperTube Type K,Soft Temper H23.1 B88

3F Seamless CopperTube Type K,Hard Temper H23.1 B88

3G Seamless CopperTube Type L,Soft Temper H23.1 B88

3H Seamless CopperTube Type L,Hard Temper H23.1 B88

3H(a) Welded CopperAlloy OFT194101A194 Water,Tube, Type B54372 Navfac"Heavy," TS15400Hard Temper

3H(b) StainlessSteel WaterTubing, TypeSL, CopperPlated Coating(HWTT439) A651

3J Seamless CopperTube, Type M,Hard and SoftTemper H23.1 B88

3J(a) Welded CopperAlloy 194 Water OFT194101ATube, Type"Standard,"Hard Temper B54372 NavfacTS154003J(b) StainlessSteel Water A268Tubing, TypeSM, CopperPlated Coating(HWTT439) A651

3K Seamless CopperTube Type DWV H23.3 B306

3L Copper PipeI.P.S. H26.1 B42

3M Copper Pipe,ThreadlessType T P andFittings H26.2 B302

3N Cast Bronzeand Wrought B16.22Solder JointPressureFitting H23.1B16.18

3O Cast Bronzeand WroughtSolder JointD W V Fittings B16.23

3P Copper AlloyWater Tube1/2 Inch and B4473/4 Inch B75

3Q Welded Brass B587Water Tube1/2 Inch and3/4 Inch

IV. LEAD PIPE AND FITTINGS

4A Lead Pipe AA WWP32544

4B Lead Pipe AAA WWP32544

4C Lead Bendsand Traps WWP32544

4D Sheet Lead QQL201d

V. SILICA AND EARTH PRODUCTS PIPE AND FITTINGS,NONMETALLIC

5A AsbestosCement C500 SSP351Pressure Pipeand Fitting C296

5B AsbestosCementWater Pipe andFittings C500 SSP351 AWWA C400

5C AsbestosCementNonpressurePipe and Fittings C428 XXP331

5D AsbestosCementPerforated UnderdrainPipe and Fittings C508

5E Vitrified Clay Pipe,Standard Strength C13and Stronger Fittings C200

5F Unglazed Clay Pipe,Extra Strength andFittings C278

5G Perforated Clay Pipeand Fittings C211

5H Borosilicate GlassPipe and Fittings60 psi

5J NonreinforcedConcreteDrain Tile C412 AASHTOM178

5K Nonreinforced AASHTOM86Concrete Pipe C14 SSP371 CSAA257.1

5L Perforated ConcretePipe, Underdrainage C444

5M Reinforced ConcretePipe C76 SSP375 CSAA257.2

5N Reinforced andPrestressed ConcretePipe, Pressure Typeand Fittings

5O Bituminized FiberDrain and Sewer Pipe D1860 SSP1540A

5P Perforated BituminizedFiber Pipe for GeneralDrainage D2311 SSP1540A

VI. PLASTIC PIPE AND FITTINGSDRAIN, WASTE AND VENT

6A AcrylonitrileButadieneStyrene(ABS) D2661 LP322a NSF14CSAB181.1FHAMPS CS270Type 1, Schedule 40Cellular core F628

6B (1) Polyvinyl Chloride(PVC) D2665 LP320a NSF14Schedule 40 Unthreaded FHAMPS CS272Schedule 80 can be CSAB181.2threadedCellular core F891

Fabricated Fittings D3311(8 to 24inch)

6B (2) Polyvinyl Chloride(PVC)Schedule 30 (3inchonly) D2949 LP001221

6B (3) Polyvinyl Chloride(PVC)Schedule 40 (14 to 24inch only) withASTM D3311 fittings D1785

6B (4) Polyvinyl Chloride(PVC)Schedule 40 and 80SDR 21 and SDR 26(6inch and larger) D2241

BUILDING SEWER

6C (1) Styrene Rubber D2852 CS228

6C (2) Polyvinyl Chloride(PVC) D3034 WWP00380a CSAB182.2F789(18 to 27inch only) F679(18inch and larger) F794

6C (3) AcrylonitrileButadieneStyrene(ABS) D2751 CSAB182.1

6C (4) Corrugated High AASHTO M294Density Polyethylene(Corrugated HDPE)(12 to 24inch)(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 Polyethylene(PE) B72.1 D2239 LP315a NSF14D2737 FHAUM31C CS255CSAB137.1

6E AcrylonitrileButadieneStyrene (ABS) B72.3 D2282 NSF14CS254

6F PolyvinylChloride (PVC) B72.2 D2241 LP1036 NSF14D1785 FHA UM41 CS256CSAB137.3

6G Polybutylene D2662 NSF14D2666 CSAB137.7

SPECIAL WASTES

6H Polyethylene D2239 LP 315a PS1069PS1169PS1269

6J Polypropylene D2146(Type II 24308)

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 an independent testing laboratory acceptable to the administrative authority. 6K Polybutylene D3309 CSAB137.8(tubing)

6L Chlorinated 119.1, D2846 NSF14polyvinyl 119.2 FHAchloride (CPVC) Bulletin#76CSAB137.6

GENERAL DRAINAGE ASTM

6M Polyethylene F405(corrugated)

VII. FIBERGLASS PIPE AND FITTINGS

7A Fiberglass pipe D2996 NSF14(reinforced NSF61thermosetting AWWA C950resin pipe)(one to 16inch)(18 to 48inch must bemanufactured inaccordance with ASTM D2996)4715.0510 WATER SERVICE PIPE. The following materials may be used for water service pipe:

For text of items A to H, see M.R.

I. Fiberglass pipe 7A. Installation must be in accordance with the manufacturer's requirements, recommendations, and guidelines. 4715.0520 WATER DISTRIBUTION PIPE. The following materials may be used for water distribution pipe:

For text of items A and B, see M.R.

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

For text of items D to J, see M.R.

K. Plastic pipe 6L and corresponding fittings. Installation must be in accordance with International Association of Plumbing and Mechanical Officials (IAPMO) Installation Standards 2093. L. Fiberglass pipe 7A. Installation must be in accordance with the manufacturer's requirements, recommendations, and guidelines. 4715.0530 BUILDING SEWERS. The following materials may be used for building sewers:

For text of items A to F, see M.R.

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. H. Bituminizedfiber drain and sewer pipe 5O, 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. 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; and B. corrugated high density polyethylene 6C(4) and approved joints. Installation must comply with ASTM D2321. 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 1A or 1B and fittings, and hubless cast iron 1K; B. Cast iron 1C or 1D with 1E 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. 4715.0580 SOIL AND WASTE PIPING ABOVE GROUND. For soil and waste piping, except special wastes, above ground, the following materials may be used:

For text of items A and B, see M.R.

C. Steel pipe 2A, wrought iron 2B with 1J fittings, and stainless 2C(b).

For text of items D and E, see M.R.

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 35 feet in total height unless an approved expansion and contraction joint is installed at intervals not to exceed 35 feet. 4715.0590 VENT PIPING BELOW GROUND. For vent piping below ground, the following materials may be used:

For text of items A and B, see M.R.

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. 4715.0600 VENT PIPING ABOVE GROUND. For vent piping above ground, the following materials may be used:

For text of items A and B, see M.R.

C. Steel 2A pipe, wrought iron 2B with 1H fitting, and stainless 2C(b);

For text of items D to G, see M.R.

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. 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 1G, and chemically resistant plastic pipe 6H or 6J. 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.

For text of item B, see M.R.

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 codeapproved type of pipe and joint that has been certified by the manufacturer to be able to pass the air test specified in part 4715.2820, or an internal hydrostatic pressure of ten pounds per square inch for ten minutes with no leakage. 4715.0810 PLASTIC JOINTS. 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 corrosionresistant material or approved crimp rings, threaded joints according to accepted standards, or special IAPMO listed fittings of other types. Large diameter water service pipe may have approved elastomericgasket pushon type joints which comply with ASTM D 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 onestep solvent cement complying with ASTM F493 and ASTM D2846 may be used for CPVC pipe. 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 traffic areas. 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, urinal, 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. 4715.1300 FLOOR DRAINS.

For text of subps 1 to 3, see M.R.

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.

For text of subp 6, see M.R.

4715.1390 SINKS. Subpart 1. Drain sizing. Sinks shall be provided with waste outlets not less than 11/2 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 31/2 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 horizontal branch serving the fixture. 4715.1430 HANGERS AND SUPPORTS.

For text of subps 1 to 6, see M.R.

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. 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 quickacting valve causing the water hammer. Where mechanical devices are used the manufacturer's specifications shall be followed as to location and method of installation. 4715.1770 MINIMUM PRESSURES REQUIRED IN WATER DISTRIBUTION SYSTEM.

For text of subpart 1, see M.R.

Subp. 2. Table of minimum flow pressure and flow rates. Flow Pressure Flow RateLocation psi gpm

Ordinary basin faucet 8 2.0Selfclosing basin faucet 8 2.0Sink faucet, 3/8 inch 8 2.0Sink faucet, 1/2 inch 8 2.0Bathtub faucet 8 6.0Laundry tub cock, 1/2 inch 8 5.0Shower 8 2.0Ball cock for closet 8 3.0Flush valve for closet 15 1535Flushometer valve for urinal 15 15.0Drinking fountains 15 0.75Still cockwall hydrant 10 5.04715.1910 IDENTIFICATION OF POTABLE AND NONPOTABLE WATER.

For text of subps 1 and 2, see M.R.

Subp. 3. Metal tags. When tags are used, potable water lines shall be identified by threeinchdiameter metal tags bearing the legend "SAFE WATER" in letters not less than onehalf inch in height. Nonpotable water lines shall be identified by firmly attached metal tags having the shape of a fourinch 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. 4715.2100 BACKFLOW PREVENTERS.

For text of items A and B, see M.R.

C. Spillproof 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. E. Doublecheck valve with intermediate atmospheric vent (DCVIAV): (1) permitted for low or moderate 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. Doublecheck 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. 4715.2110 TYPES OF DEVICES REQUIRED WHERE AN AIR GAP CANNOT BE PROVIDED. 1. Only allowedwhere noback pressureis possibleSVBDCV or HoseRPZ IAV DCVA PVB AVB VBA. Boiler, other than Xone or twofamilyresidentialB. Boiler, one ortwofamily residential X X

For text of items C to FF, see M.R.

4715.2210 PRESSURE RELIEF VALVES.

For text of subpart 1, see M.R.

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).

For text of subps 3 and 4, see M.R.

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 corrosionresistant 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. 4715.2300 LOAD ON DRAINAGE PIPING.

For text of subps 1 to 2a, see M.R.

Subp. 3. Table of fixture unit values for various plumbing

fixtures.

MinimumFixture FixtureUnit Trap andType of Fixture Value Drain Size

Clothes washer (domestic use) 2 11/2Clothes washer (single unit,discharge to standpipe) 2 2Clothes washer (public use in groups of3 or more) 6 eachBath tub with or without shower 2 11/2Bidet 2 11/2Dental unit or cuspidor 1 11/4Drinking fountain 1 11/4Dishwasher, domestic (gravity drain) 2 11/2Dishwasher, commercial 4 2Floor drain with 2 inch waste 2 2Floor drain with 3 inch waste 3 3Floor drain with 4 inch waste 4 4Lavatory 1 11/4Laundry tray (1 or 2 compartment) 2 11/2Shower stall, domestic 2 11/2Shower (gang) per head 1SINKS:Classroom, with or without 2 11/2drinking fountainCombination, sink and tray (withdisposal unit) 3 11/2Combination, sink and tray (withone trap) 2 11/2Domestic 2 11/2Domestic, with disposal unit 2 11/2Surgeons 3 11/2Laboratory, cup sink 1 11/2Flushrim or bedpan washer 6 3Service 3 2Pot or scullery 4 2Soda fountain 2 11/2Commercial, flat rim, bar,or counter 3 11/2Wash, circular, or multiple (perset of faucets) 2 11/2URINAL pedestal, wall hung, with 3 inchtrap (blowout and syphon jet) 6 3Wall hung with 2 inch trap 3 2Wall hung with 11/2 inch trap 2 11/2Trough (per 6 foot section) 2 11/2Stall 3 2WATER CLOSET 6 3Unlisted Fixture or Trap Size11/4 inch 111/2 inch 22 inch 321/2 inch 43 inch 54 inch 64715.2330 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 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. 4715.2440 DESIGN OF SUMPS.

For text of subps 1 to 6, see M.R.

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 UBC Section

1711 509 may be used in lieu of covers. 4715.2520 VENT STACKS AND STACK VENTS. Subpart 1. Vent stack required. Every building in which plumbing is installed shall have at least one threeinch vent stack (or stack vent) carried full size through the roof as provided in part 4715.2330. A vent 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 oneeighth 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 crossconnected 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. 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.

For text of subps 4 to 6, see M.R.

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. 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.

For text of subp 2, see M.R.

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 21/2 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.

For text of subps 2 to 4, see M.R.

4715.2710 SIZE OF BUILDING STORM DRAINS AND LEADERS.

For text of subps 1 and 2, see M.R.

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 forDiameter of Drain Drains of Various SlopesInches 1/8 in. Slope 1/4 in. Slope 1/2 in. Slope

Square Feet Square Feet Square Feet3 822 1,160 1,6444 1,880 2,650 3,7605 3,340 4,720 6,6806 5,350 7,550 10,7008 11,500 16,300 23,00010 20,700 29,200 41,40012 33,300 47,000 66,60015 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 AreaInches Square Feet

2 72021/2 1,3003 2,2004 4,6005 8,6506 13,5008 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 crosssectional area of the leader. Subp. 6. Values for continuous flow. If there is a continuous or semicontinuous discharge into the building storm drain or building storm sewer, as from a pump, ejector, airconditioning 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 fourinch rainfall. 4715.2760 ROOF AND DECK DRAINS.

For text of subpart 1, see M.R.

Subp. 2. Overflow drains. For overflow drains refer to Section 3207(c) 1506 of the Uniform Building Code.

For text of subps 3 and 4, see M.R.

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 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. 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 air tested upon completion of the rough piping. 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. 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

the Standard Utility 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, except that an air test

may be required for any section of the building storm sewer that

passes through contaminated soils or contaminated water is incorporated by reference, is not subject to frequent change, and is available in the office of the commissioner of administration.

For text of subps 3 to 7, see M.R.