SPS 382.40(4)(c)2.2. Control valves shall be installed in water distribution systems serving one- and 2-family dwellings as specified in this subdivision. SPS 382.40(4)(c)2.a.a. If a water meter is provided, a control valve shall be installed within 3 feet of developed length downstream from the outlet of the water meter. If bypass piping is provided around a water meter, a control valve shall be installed in the bypass piping. SPS 382.40 NoteNote: See sub. (8) (d) 3. for the requirements relating to the bypassing of water meters.
SPS 382.40(4)(c)2.b.b. A control valve shall be installed in the supply piping to each water heater and water treatment device and in the fixture supply to each water closet, exterior hose bibb, plumbing appliance and piece of equipment. When the valve is an internal part of the water treatment device, the device shall be removable for service. SPS 382.40(4)(c)2.c.c. If a hot water circulation system is provided, a control valve shall be installed on both the inlet and outlet piping to the circulation pump. If a hot water circulation system has 2 or more return pipe lines, a balancing control valve shall be installed in each return piping line. SPS 382.40(5)(a)(a) General. Water heating systems shall be sized to provide sufficient hot water to supply peak demand, except for a tankless type water heater that meets the requirements of par. (am). SPS 382.40(5)(am)(am) Tankless type water heaters. All tankless type water heaters shall have minimum flow rate as specified in this paragraph. SPS 382.40(5)(am)1.1. The minimum flow rate of a tankless type water heater may be obtained by multiplying 0.65 by the calculated hot water gallons per minute demand, as determined by Tables 382.40–1t and 382.40–3, provided the heater will achieve a water temperature of 110°F at the terminal fitting or faucet. SPS 382.40(5)(am)2.2. The sizing method in subd. 1. may not be used for sizing a water heater serving a high-flow fixture, a hose bibb, a hydrant, or a fixture that is required to have a supply line with a diameter larger than 1/2 inch. SPS 382.40(5)(am)3.3. For the purposes of subd. 2, “high-flow fixture” means a fixture with a flow rate of more than 4 gallons per minute, at 80 pounds per square inch, and a water velocity not exceeding 8 feet per second. SPS 382.40(5)(b)(b) Temperature maintenance. Except as provided in par. (bm), the developed length of hot water distribution piping from the source of the hot water supply to a plumbing fixture or appliance exceeds 100 feet, a circulation system or self-regulating electric heating cable shall be provided to maintain the temperature of the hot water within the distribution piping. SPS 382.40(5)(b)1.1. If a circulation system is used to maintain the temperature, no uncirculated hot water distribution piping may exceed 25 feet in developed length. SPS 382.40(5)(b)2.2. If a self-regulating electric heating cable is used to maintain the temperature, the cable shall extend to within 25 feet of each fixture or the appliance. SPS 382.40(5)(b)3.3. Water distribution piping conveying circulated water or served by a self-regulating electric heating cable shall be insulated to limit the heat loss at the external surface of the pipe insulation to a maximum of 25 BTUs per hour per square foot for aboveground piping and 35 BTUs per hour per square foot for underground piping. The maximum heat loss shall be determined at a temperature differential, T, equal to the maximum water temperature minus a design ambient temperature no higher than 65°F. SPS 382.40(5)(b)4.4. Water distribution piping served by self-regulating electric heating cable shall be identified as being electrically traced in accordance with ch. SPS 316. SPS 382.40(5)(b)5.5. The installation of self-regulating electric heating cable may be subcontracted by a plumber to another trade. SPS 382.40(5)(b)6.6. All hot water circulation system connections shall be made downstream of the control valve serving the water heating device. SPS 382.40(5)(b)7.7. Hot water circulation piping and tubing may not exceed the maximum velocity requirements specified per the manufacturer. SPS 382.40 NoteNote: See A-382.40 (5) for pipe insulation requirements.
SPS 382.40(5)(bm)(bm) Temperature maintenance; public buildings. Except as required in par. (b) all public lavatories in public buildings shall comply with the provisions of sub. (5) (b), except that allowable hot water supply distances for any fixture shall be calculated from the nearest source of hot water using the method in subd. 1. For public lavatories the allowable supply distance shall comply with the method in either subd. 1 or 2. of this section. In this section hot water sources shall include water heaters, circulating water systems, and self-regulating heat trace temperature maintenance systems. SPS 382.40(5)(bm)1.1. Maximum allowable pipe length method: Under this method the distance from a hot water supply to a fixture, public lavatory, or appliance may not exceed the distances in Table 382.40-1d. Fixture fittings, fixture supply connectors, and faucets may not be part of this calculation. SPS 382.40(5)(bm)2.2. Maximum allowable volume method: Under this method the maximum allowable volume of water between a hot water source and a public lavatory may not exceed 8 ounces. The allowable volume shall be the sum of the internal volume of all pipe, but may not include volume contained within fixture shutoff valves, within flexible water supply connectors to a fixture fitting, or within a fixture fitting. Pipe volume shall be calculated using the values in Table 382.40-1h. SPS 382.40 NoteNote: Water heaters are to be installed in accordance with the requirements specified in chs. SPS 361 to 366 and chs. SPS 320 to 325 with respect to energy efficiency, enclosures and venting. SPS 382.40(5)(d)(d) Safety devices. Water heaters shall be equipped with safety devices as specified in this paragraph. SPS 382.40(5)(d)1.1. All pressurized storage-type water heaters and unfired hot water storage tanks shall be equipped with one or more combination temperature and pressure relief valves. The temperature steam rating of a combination temperature and pressure relief valve or valves shall equal or exceed the energy input rating in BTU per hour of the water heater. No shut off valve or other restricting device may be installed between the water heater or storage tank and the combination temperature and pressure relief valve. SPS 382.40 NoteNote: The temperature steam rating of a combination temperature and pressure relief valve is commonly referred to as the AGA temperature steam rating.
SPS 382.40(5)(d)2.2. All pressurized non-storage type water heaters shall be provided with a pressure relief valve installed at the hot water outlet with no shut off valve between the heater and the relief valve. SPS 382.40(5)(d)3.3. Temperature and pressure relief valves shall be installed so that the sensing element of the valve extends into the heater or tank and monitors the temperature in the top 6” of the heater or tank. SPS 382.40(5)(d)4.4. A vacuum relief valve shall be installed in each water heater and hot water storage tank which, when measured from the bottom of the heater or tank, is located more than 20 feet above any faucet or outlet served by the heater or tank. SPS 382.40(5)(d)5.5. Every relief valve which is designed to discharge water or steam shall be connected to a discharge pipe. SPS 382.40(5)(d)5.b.b. The discharge pipe and fittings shall have a diameter not less than the diameter of the relief valve outlet. SPS 382.40(5)(d)5.e.e. The discharge pipe shall be installed to drain by gravity flow to a floor served by a floor drain or to a receptor in accordance with s. SPS 382.33 (8). The outlet of the discharge pipe shall terminate within 6” over the floor or receptor, but not less than a distance equal to twice the diameter of the outlet pipe. The outlet of the discharge pipe may not be threaded. SPS 382.40(5)(d)5.f.f. The discharge pipe for a water heater shall terminate within the same room or enclosure within which the water heater or hot water storage tank is located. SPS 382.40(5)(e)1.1. All hot water supply systems shall be equipped with automatic temperature controls capable of adjustments from the lowest to the highest acceptable temperature settings for the intended use. SPS 382.40(5)(e)2.2. A separate means shall be provided to terminate the energy supplied to each water heater and each hot water circulation system. SPS 382.40(6)(a)(a) Intermittent flow fixtures. The load factor for intermittent flow fixtures on water supply piping shall be computed in terms of water supply fixture units as specified in Tables 382.40-1t and 382.40-2 for the corresponding fixture and use. Water supply fixture units may be converted to gallons per minute in accordance with Table 382.40-3 or 382.40-3e. SPS 382.40(6)(b)(b) Continuous flow devices. The load factor for equipment which demands a continuous flow of water shall be computed on the basis of anticipated flow rate in terms of gallons per minute. a All nonpotable water outlets shall be identified at the point of use for each outlet with the following legends or as otherwise approved by the department.
b Tag should reflect the intended use.
c Serving an individual or similar plumbing fixtures or appliances.
SPS 382.40(6)(c)(c) Water heating sizing alternate approval. The load factor for an individual water heater serving an individual residence, apartment, living unit of a hotel or motel, and similar places where plumbing fixtures are intended for use by an individual or family, to the exclusion of all others, may be calculated as follows: SPS 382.40(6)(c)1.1. The minimum flow rate of a water heater may be obtained by multiplying the hot water demand calculated in accordance with Table 382.40-1b by a factor of 0.65. SPS 382.40(6)(c)2.2. The flow rate for a storage tank type water heater may be calculated based on a 70% usable storage plus the recovery rate and a 10 minimum draw time. SPS 382.40(6)(c)3.3. The flow rate for tankless type water heaters shall be based on a temperature increase that will provide 110°F at the most remote terminus. SPS 382.40(6)(c)4.4. This alternate sizing method may not be applied to any of the following: SPS 382.40(6)(c)4.a.a. Water heaters serving high flow fixtures, hose bibs, hydrants or fixtures requiring 1/2 inch supply piping. High flow fixtures are fixtures with flow rates greater than 4 gpm at 80 psig and a water velocity less than or equal to 8 feet per second. SPS 382.40 NoteNote: See appendix for further explanatory information and examples.
SPS 382.40 NoteNote: Values not specified in the table may be calculated by interpolation.
SPS 382.40(7)(7) Sizing of water supply piping. The sizing of the water supply system shall be based on the empirical method and limitations outlined in this subsection, an approved alternate standard per s. SPS 381.20 (2), or an analysis provided by a Wisconsin registered architect, registered professional engineer or permitted designer of engineering systems – plumbing. SPS 382.40 NoteNote: See appendix for details for alternative methods for sizing of the water supply piping of one- and 2-family and apartment buildings.
SPS 382.40(7)(a)(a) Methodology. The determination of minimum pipe sizes shall take into account the pressure losses which occur throughout the entire water supply system and the flow velocities within the water distribution system. Calculations for sizing a water distribution system shall include: SPS 382.40(7)(a)1.1. The load factor in water supply fixture units or gallons per minute on the piping; SPS 382.40(7)(a)4.4. The pressure losses due to flow through water heaters, water treatment devices, water meters and backflow preventers; SPS 382.40(7)(a)5.5. The minimum flow pressure needed at the controlling plumbing fixture; and SPS 382.40(7)(a)6.6. The pressure losses due to flow friction through piping, fittings, valves and other plumbing appurtenances. This pressure loss may be calculated in terms of equivalent lengths of piping. The equivalent length of piping to a controlling plumbing fixture, including fittings, valves and other appurtenances, may be obtained by multiplying the developed length by 1.5. SPS 382.40(7)(b)(b) Private water mains and water services. Private water mains and water services shall be designed to supply water to the water distribution systems to maintain the minimum flow pressures specified in par. (d), but shall not be less than 3/4” in diameter. SPS 382.40(7)(c)(c) Maximum loading. The calculated load on any portion of the water distribution system may not exceed the limits specified in Tables 382.40-4 to 382.40-9. SPS 382.40(7)(d)1.1. Except as provided in subd. 1. a. to c., water supply systems shall be designed to provide at least 8 psig of flow pressure at the outlets of all fixture supplies. SPS 382.40(7)(d)1.a.a. The flow pressure at the outlets of the fixture supplies serving siphonic type urinals, washdown type urinals and washdown type water closets, siphonic type flushometer water closets and campsite water supply hose connections shall be at least 15 psig. SPS 382.40(7)(d)1.b.b. The flow pressure at the outlets of the fixture supplies serving one piece tank type water closets, pressure balance mixing valves, manufactured homes, and thermostatic mixing valves shall be at least 20 psig. SPS 382.40(7)(d)1.c.c. The flow pressure at the outlets of the fixture supplies serving blowout type urinals and blowout type water closets shall be at least 25 psig. SPS 382.40(7)(d)1.d.d. The flow pressure at the outlets of the fixture supplies serving any other fixture shall be the minimum pressure required by the manufacturer for the fixture, appliance, or equipment to operate. SPS 382.40(7)(d)2.a.a. Except as provided in subd. 3., if the water pressure available from a water main or private water supply exceeds 80 psig, a pressure reducing valve and strainer, if a strainer is not a component of the valve, shall be installed in the water distribution system. SPS 382.40(7)(d)2.b.b. A pressure reducing valve required under subd. 2. a. shall be installed upstream from all plumbing fixtures and plumbing appliances and downstream from the water meter of an utility, if a meter is provided. SPS 382.40(7)(d)3.3. A pressure reducing valve shall not be required to be installed in a water distribution system which supplies water directly to a water pressure booster pump.
