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Air Conditioner Manufacturer .................................
Air Conditioner Model ........................................
Certified Capacity-B.T.U./Hr. in accordance with the appropriate Air Conditioning and Refrigeration Institution Standards.
The central air conditioning system provided with this home has been sized assuming an orientation of the front (hitch end) of the home facing ____. On this basis the system is designed to maintain an indoor temperature of 75° F when outdoor temperatures are ____ F dry bulb and ____ f wet bulb.
The temperature to which this home can be cooled will change depending upon the amount of exposure of the windows of this home to the sun's radiant heat. Therefore, the home's heat gains will vary dependent upon its orientation to the sun and any permanent shading provided. Information concerning the calculation of cooling loads at various locations, window exposures and shadings are provided in Chapter 22 of the 1972 edition of the ASHRAE Handbook of Fundamentals.
Information necessary to calculate cooling loads at various locations and orientations is provided in the special comfort cooling information provided with this mobile home.
(2) Alternative 2. For each home suitable for a central air cooling system, the manufacturer shall provide the following statement: 'This air distribution system of this home is suitable for the installation of a central air conditioning system.'
EXAMPLE ALTERNATE 2

COMFORT COOLING CERTIFICATE

Mobile Home Manufacturer......................................
Plant Location ...............................................
Mobile Home Model ............................................

This air distribution system of this home is suitable for the installation of central air conditioning.
The supply air distribution system installed in this home is sized for Mobile Home Central Air Conditioning System of up to ____ B.T.U./Hr. rated capacity which are certified in accordance with the appropriate Air Conditioning and Refrigeration Institute Standards. When the air circulators of such air conditioners are rated at 0.3 inch water column static pressure or greater for the cooling air delivered to the mobile home supply air duct system.
Information necessary to calculate cooling loads at various locations and orientations is provided in the special comfort cooling information provided with this mobile home.
(3) Alternative 3. If the mobile home is not equipped with an air supply duct system, or if the manufacturer elects not to designate the home as being suitable for the installation of a central air conditioning system, the manufacturer shall provide the following statement: 'This air distribution system of this home has not been designed in anticipation of its use with a central air conditioning system.'
EXAMPLE ALTERNATVE 3

COMFORT COOLING CERTIFICATE

Mobile Home Mfg...............................................
Plant Location ...............................................
Mobile Home Model ............................................
The air distribution system of this home has not been designed in anticipation of its use with a central air conditioning system.
(b) For each home designated as suitable for central air conditioning the manufacturer shall provide the maximum central mobile home air conditioning capacity certified in accordance with the appropriate A.R.I. standards and in accordance with 280.715(a)(3). If the capacity information provided its based on entrances to the air supply duct at other than the furnace plenum, the manufacturer shall indicate the correct supply air entrance and return air exit locations.

(c) Confort cooling information. For each mobile home designated either 'suitable for' or 'provided with' a central air conditioning system the manufacturer shall provide comfort cooling information specific to the mobile home necessary to complete the cooling load calculations. The comfort cooling information shall include a statement to read as follows:
To determine the required capacity of equipment to cool a home efficiently and economically, a cooling load (heat gain) calculation is required. The cooling load is dependent on the orientation, location and the structure of the home. Central air conditioners operate closely approximates the calculated cooling load. Each homes air conditioner should be sized in accordance with Chapter 22 of the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Handbooks of Fundamentals, once the location and orientation are known.
INFORMATION PROVIDED BY THE MANUFACTURER

NECESSARY TO CALCULATE SENSIBLE HEAT GAIN

Walls (without windows and doors)......'U'...................

Ceilings and roofs of light color .....'U'...................
Ceilings and roofs of dark color ......'U'...................
Floors ................................'U'...................
Air ducts in floor ....................'U'...................
Air ducts in ceiling ..................'U'...................
Air ducts installed outside the home...'U'...................
Information necessary to calculate duct area.
Subpart G--Plumbing Systems

280.601. Scope.
Subpart G of this Standard covers the plumbing materials, fixtures, and equipment installed within or on mobile homes. It is the intent of this subpart to assure water supply, drain, waste and vent systems which permit satisfactory functioning and provide for health and safety under all conditions of normal use.
280.602. Definitions.
(a) The following definitions are applicable to Subpart G only only:
(1) 'Accessible,' when applied to a fixture, connection, appliance or equipment, means having access hereto, but which may require removal of an access panel or opening of a door.
(2) '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, water supplied appliances, or other device and the flood level rim of the receptacle.
(3) 'Anti-Siphon Trap Vent Device' means a device which automatically opens to admit air to a fixture drain above the connection of the trap arm so as to prevent siphonage, and closes tightly when the pressure within the drainage system is equal to or greater than atmospheric pressure so as to prevent the escape of gases from the drainage system into the mobile home.

(4) 'Backflow' means the flow of water or other liquids, mixtures, or substances into the distributing pipes of a potable supply of water from any source or sources other than its intended sources.
(5) 'Backflow Connection' means any arrangement whereby backflow can occur.
(6) 'Backflow Preventer' means a device or means to prevent backflow.
(7) 'Branch' means any part of the piping system other than a riser, main or stack.
(8) 'Common Vent' means a vent connecting at the junction of fixture drains and serving as a vent for more than one fixture.
(9) 'Continuous Vent' means a vertical vent that is a continuation of the drain to which it connects.
(10) 'Continuous Waste' means a drain from two or more fixtures connected to a single trap.

(11) 'Critical Level' means a point established by the testing laboratory (usually stamped on the device by the manufacturer) which determines the minimum elevation above the flood level rim of the fixture or receptacle served on which the device may be installed. When a backflow prevention device does not bear a critical level marking, the bottom of the vacuum breaker, combination valve, or of any such approved or listed device shall constitute the critical level.
(12) 'Cross Connection' means any physical connection or arrangement between two otherwise separate systems or sources, one of which contains potable water and the other either water, steam, gas or chemical of unknown or questionable safety whereby there may be a flow from one system or source to the other, the direction of flow depending on the pressure differential between the two systems.
(13) 'Developed Length' means that length of pipe measured along the center line of the pipe and fittings.
(14) 'Diameter,' unless otherwise specifically stated, means the nominal (inside) diameter designated commercially.

(15) 'Drain' means a pipe that carries waste, water, or water-borne waste in a drainage system.
(16) 'Drain Connector' means the removable extension, consisting of all pipes, fittings and appurtenances, from the drain outlet to the drain inlet serving the mobile home.
(17) 'Drain Outlet' means the lowest end of the main or secondary drain to which a sewer connection is made.
(18) 'Drainage System' means all piping within or attached to the structure that conveys sewage or other liquid waste to the drain outlet, not including the drain connector.
(19) 'Fixture Drain' means the drain from the trap of a fixture to the junction of that drain with any other drain pipe.
(20) 'Fixture Supply' means the water supply pipe connecting a fixture to a branch water supply pipe or directly to a main water supply pipe.
(21) 'Flood-Level' means the level in the receptacle over which water would overflow to the outside of the receptacle.
(22) 'Flooded' means the condition which results when the liquid in a container or receptable rises to the flood-level.
(23) 'Flush Tank' means that portion of a toilet that is designed to contain sufficient water to adequately flush the fixture.
'Flush Valve' means a device located at the bottom of a flush tank for flushing a toilet.
'Flushometer Valve' means a device which discharges a predetermined quantity of water to a fixture for flushing purposes and is closed by direct water pressure.
(26) 'Grade' means the fall (slope' of a pipe in reference to a horizontal plane expressed in inches per foot length.
(27) 'Horizontal Branch' means any pipe extending laterally, which receives the discharge from one or more fixture drains and connects to the main drain.
(28) 'Horizontal Pipe' means any pipe or fitting which makes an angle of not more than 45 degrees with the horizontal.
(29) 'Individual Vent' means a pipe installed to vent a fixture drain.
(30) 'Inlet Coupling' means the terminal end of the water system to which the water service connection is attached. It may be a swivel-fitting or threaded pipe end.
(31) 'Main' means the principal artery of the system to which branches may be connected.
(32) 'Main Drain' means the lowest pipe of a drainage system which receives sewage from all the fixtures within a mobile home and conducts these wastes to the drain outlet.
(33) 'Main Vent' means the principal artery of the venting system to which vent branches may be connected.
(34) 'Offset' means a combination of a pipe and/or fittings that brings one section of the pipe out of line but into a line parallel with the other section.
(35) 'Pitch.' See grade.
(36) 'Plumbing Fixtures' means receptacles, devices, or appliances which are supplied with water or which receive liquid borne wastes for discharge into the drainage system.
(37) 'Plumbing System' means the water supply and distribution pipes; plumbing fixtures, faucets and traps; soil, waste and vent pipes; and water-treating or water-using equipment.
(38) 'Primary Vent.' See Main Vent.
(39) 'Relief Vent' means an auxiliary vent which permits additional circulation of air in or between drainage and vent systems.
(40) 'Secondary Vent' means any vent other than the main vent or those serving each toilet.
(41) 'Sewage' means any liquid waste containing animal or vegetable matter in suspension or solution, and may include liquids containing chemicals in solution.
(42) 'Siphonage' means the loss of water seal from fixture traps resulting from partial vacuum in the drainage system which may be of either of the following two types, or a combination of the two:
(a) Self-siphonage resulting from vacuum in a fixture drain generated solely by the discharge of the fixture served by the drain, or,
(b) Induced siphonage resulting from vacuum in the drainage system generated by the discharge of one ormore fixtures other than the one under observation.
(43) 'Toilet Drain' means that part of the drainage piping which receives the discharge from each individual toilet.
(44) 'Trap' means a fitting or device designed and constructed to provide a liquid seal that will prevent the back passage of air without materially affecting the flow of liquid waste through it.
(45) 'Trap Arm' means the portion of a fixture drain between a trap and its vent.
(46) 'Trap Seal' means the vertical depth of liquid that a trap will retain.
(47) 'Vacuum Breaker.' See Backflow Preventer.
(48) 'Vent Cap' means the device or fitting which protects the vent pipe from foreign substance with an opening to the atmosphere equal to the area of the vent it serves.
(49) 'Vent System' means that part of a piping installation which provides circulation of air within a drainage system.
'Vertical Pipe' means any pipe or fitting which makes an angle of not more than 45 degrees with the vertical.
(51) 'Water Connection' means the fitting or point of connection for the mobile home water distribution system designed for connection to a water supply.
(52) 'Water Connector' means the removable extension connecting the mobile home water distribution system to the watter supply.
(53) 'Water Distribution System' means potable water piping within or permanently attached to the mobile home.
(54) 'Wet Vent' means a vent which also serves as a drain for one or more fixtures.
(55) 'Wet Vented Drainage System' means the specially designed system of drain piping that also vents one or more plubming fixtures by means of a common waste and vent pipe.
280.603. General Requirements.
(a) Minimum requirements. Any plumbing system installed in a mobile home shall conform, at least, with the provisions of this subpart.
(1) General. The plumbing system shall be of durable material, free from defective workmanship, and so designed and constructed as to give satisfactory service for a reasonable life expectancy.
(2) Conservation. Water closets shall be selected and adjusted to use the minimum quantity of water consistent with proper performance and cleaning.
(3) Connection to drainage system. All plumbing, fixtures, drains, appurtenances, and appliances designed or used to receive or discharge liquid waste or sewage shall be connected to the mobile home drainage system in a manner provided by this standard.
(4) Workmanship. All design, construction, and workmanship shall be in conformance with accepted engineering practices and shall be of such character as to secure the results sought to be obtained by this standard.
(5) Components. Plumbing materials, devices, fixtures, fittings, equipment, appliances, and accessories intended for use in or attached to a mobile home, and not shown in the Table in 280.604, shall be listed or certified by an approved listing agency, or be specifically approved by the Department when Listing by an approval listing agency is not available.
Prohibited fittings and practices. (i) Drainage or vent piping shall not be drilled and tapped for the purpose of making connections. (ii) Except as specifically provided elsewhere in this standard, vent pipes shall not be used as waste or drain pipes. (iii) Fittings, connections, devices, or methods of installatoin that obstruct or retard the flow of sewage, or air in the drainage or venting systems in an amount greater than the normal frictional resistance to flow shall not be used unless their use acceptable in this standard or their use is accepted as having a desirable and acceptable function of ultimate benefit to the proper and continued functioning of the plumbing system. (iv) Cracks, holes, or other imperfections in materials shall not be concealed by welding, brazing, or soldering or by paint, wax, tar, or other leak-sealing or repairing agents. (v) Piping, fixtures or equipment shall be located so as not to interfere with the normal use or with the normal operation and use of windows, doors or other required facilities. (vi) Galvanized pipe shall not be bent or welded.
(7) Alignment of fittings. All valves, pipes, and fittings shall be installed in correct relationship to the direction of flow.
(b) Protective requirements.
(1) Cutting structural members. Structural members shall not be unnecessarily or carelessly weakened by cutting or notching.
(2) Exposed piping. All piping, pipe threads, hangers, and support exposed to the weather, water, mud, and road hazard, and subject to damage therefrom, shall be painted, coated, wrapped, or otherwise protected from deterioration.
(3) Road damage. Pipes, supports, drains, outlets, or drain hoses shall not extend or protrude in a manner where they could be unduly subjected to damage during transit.
(4) Freezing. All piping and fixtures subject to freezing temperatures shall be insulated or protected to prevent freezing, under normal occupancy. The manufacturer shall provide: (i) Written installation instructions for the method(s) required for compliance to this section; (ii) a statement inhis installation instrauctions that if heat tape is used it shall be listed for use with mobile homes; (iii) a receptacle outlet conveniently located for use of a heat tape and in compliance with 280.806(b).
(5) All piping, except the fixture trap, shall be designed to allow drainage.
(6) Rodent resistance. All exterior opernings around piping and equipment shall be sealed to resist the entrance of rodents.
(7) Piping and electrical wiring shall not pass through the same holes in walls, floors or roofs. Plastic piping shall not be exposed to heat in excess of manufacturers recommendation or radiation from heat producing appliances.
280.604. Materials.
(a) Minimum standards. Materials, fixtures, or devices used or entering into the construction of plumbing systems in any mobile home shall be free from defects and shall conform to approved standards or to applicable standards in the following Table.
(b) Specific usage. Each of the sections following the Table indicates specifically the type of material presently permitted for use in the various parts of the plumbing system.
280.605. Joints and Connections.
(a) Tightness. Joints and connections in the plumbing system shall be gastight and watertight for the pressures required under testing procedures.
(1) Assembling of pipe. All joints and connections shall be correctly assembled for tightness. Pipe threads shall be fully engaged with the threads of the fitting. Plastic pipe and copper tubing shall be inserted to the full depth of the solder cup or welding sockets for each fitting. Pipe threads and slip joints shall not be wrapped with string, paper, putty, or similar fillers.






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Materials ANSI ASTM FS Other
Standard
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Ferrous pipe and
fittings
Cast iron screwed B16.4-1971
fittings
Malleable iron screwed B16.3-1971
fittings
Special cast iron IAPMO
fittings PS 5-1966
Welded wrought iron B36.2-1969 A72-1968
pipe
Wrought steel and B36.10-1970
wrought iron pipe
Black and hot dipped
zinc-coated
(galvanized) welded

and seamless
steel pipe A-120-1972a
Welded and seamless B125.1-1972 A53-1972a
steel pipe
Pipe threads (except B2.1-1968
dry-seal)
Cast iron soil piping A112.5.1- A74-1974 WW-P-
and fittings 1971 401D-1969
Nonferrous pipe and
fittings
Seamless copper, pipe, H26.1-1973 B42-1972
standard sizes
Wrought seamless
copper and copper H23.4-1973 B231-1971
alloy tube
Seamless copper water H23.1-1973 B88-1972
tube
Copper drainage tube H23.6-1973 B306-1973
(DWV)
Wrought copper and
bronze solder joint B16.22-1973

pressure fittings
Wrought copper and
wrought copper
alloy solder-joint
drainage fittings B16.29-1966
Cast brass
solder-joint
pressure fittings B16.18-1972
Cast bronze
solder-joint drainage
fittings-DWV B16.23-1969
Cast bronze fittings
for flared
copper tubes B16.26-1967
Seamless red brass
pipe, standard sizes H27.1-1973 B43-1972
Cast bronze threaded
fittings, 150 and
300 pound B16.15-1971
Plastic Pipe and
Fittings

ABS plastic drain,
waste, and vent
pipe and fittings D2251-1973 L-P322B-1973 IAPMO
PS17-71
NSF 14-1970
PVC plastic drain,
waste, and vent
pipe and fittings D2665-1973 L-P-320B-1973 LAPMO
PS27-69 1973
NSF-14-1970
chlorinated poly
(vinyl/chloride)
(CPVC) plastic hot
water distribution
systems D2846-1973 NSF-14-1970
Polybutylene (PB)
plastic pipe (SDR-PR) D2662-1973
Polybutylene (PB)
plastic hot water
distribution systems D3309-1974
miscellaneous

Pipe nipples, threaded WW-N
351B(1)-1970
Rubber gaskets for
cast iron soil pipe
fittings C364-1970
Backflow prevention A112.14.1- IAPMO PS
devices 1975 31-1971
Valve, bronze, gate
23-150 and
200 pound WW-V-
34D-1973
Valve, cast-iron gate,
threaded and flanges WW-V-
56B-1971
Plumbing-fixture- HH-C-
setting compound 536A-1954
Cast brass and tubing IAPMO
P-traps PS 2-1966
Relief valves and
automatic gas
shutoff devices for Z21.22

hot water supply [FN1]-1971
systems
Solvent cement for ABS
plastic pipe and
fittings D2238-1973 NSF-14-1970
Solvent cement for PVC
plastic pipe
and fittings D2564-1973 NSF-14-1970
Anti-siphon strap vent NSF-24
device
Diversion tees and IAPMO PS 9-66
twin waste elbow
Flexible copper water IAPMO PS 14-
connectors 1971
Dishwater drain IAPMO PS
airgaps 23-1968
Coated flexible metal
gas connectors
for exterior use IAPMO TSC 9-
1972
Plumbing fixtures

Plumbing fixtures for WW-P-541D-
land use 1971
Vitreous china A112.19.2--
plumbing fixtures 1973
Enameled cast iron A112.19.1--
plumbing 1973
Porcelain enameled
formed steel
plumbing fixtures IAPMO TSC-22
1972
Formed metal
porcelain-enameled
sanitaryware IAPMO PS3-
1967
Plastic bathtub units Z124.1-1974
Gel-coated glass-fiber
reinforced polyester
resin shower receptor
and shower stall Z124.2-1967
units
Stainless steel

plumbing fixtures--
residential use CS-243-1962
NSF-24-1972
Drains for
prefabricated and
precast showers IAPMO PS 4-
1966
NSF-24-1972
Cultured marble IAPMO PS 1H-
lavatory 1973:
CMI-LS 1-73
Performance
specifications and
methods of test for
safety glazing
material used in Z97.1-1972 NSF-24-72
buildings

[FN1] With Addends.

(2) Threaded joints. Threads for screw pipe and fittings shall conform to the approved or listed standard. Pipe ends shall be reamed out to size of bore. All burrs, chips, cutting oil and foreign matter shall be removed. Pipe joint cement or thread lubricant shall be of approved type and applied to male threads only.
(3) Solder joints. Solder joints for tubing shall be made with approved or listed solder type fittings. Surfaces to be soldered shall be cleaned bright. The joints shall be properly fluxed with noncorrosive paste type flux and made with approved or listed 50-50 solder or an approved solder having a higher melting temperature.
(4) Plastic pipe, fittings and joints. Plastic pipe and fittings shall be joined by installation methods recommended by the manufacturer or in accordance with the provisions of a recognized, approved, or listed standard.
(5) Union joints. Metal unions in water piping shall have metal-to-metal ground seats.
(6) Flared joints. Flared joints for soft-copper water tubing shall be made with approved or listed fittings. The tubing shall be expanded with a proper flaring tool.
(7) Cast iron soil pipe joints. Approved or listed cast iron pipe may be joined as follows: (i) Approved or listed hubless pipe as per the manufacturer's recommendation. (ii) Hub and plain-end soil pipe may be joined by compression fittings per the manufacturer's recommendation.
280.606. Traps and Cleanouts.
(a) Traps.
(1) Traps required. Each plumbing fixture, except listed toilets, shall be separately trapped by approved water seal 'P' traps. All traps shall be effectively vented.
(2) Dual fixtures. A two-compartment sink, two single sinks, two lavatories, or a single sink and a single lavatory with waste outlets not more than 30 inches apart and in the same room and flood level rims at the same level may be connected to one 'P' trap and may be considered as a single fixture for the purpose of drainage and vent requirements.

(3) Prohibited traps. A trap which depends for its seal upon concealed interior partitions shall not be used. Full 'S' traps, bell traps, drum traps, crown-vented traps, and running traps are prohibited. Fixtures shall not be double-trapped.
(4) Material and design. Each trap shall be self-cleaning with a smooth and uniform interior waterway. Traps shall be manufactured of cast iron, cast brass, or drawn brass tubing of not less than No. 20 Brown and Sharpe gage, or approved or listed plastic, or other approved or listed material. Union joints for a trap shall be beaded to provide a shoulder for the union nut. Each trap shall have the manufacturer's name stamped or cast in the body of the trap, and each tubing shall show the gage of the tubing.
(5) Trap seal. Each 'P' trap shall have a water seal of not less than 2 inches and not more than 4 inches and shall be set true to its seal.
(6) Size. Traps shall be not less than 1-1/4 inches in diameter. A trap shall not be larger than the waste pipe to which it is connected.
(7) Location. Each trap shall be located as close to its vent and to its fixture outlet as structural conditions will permit.

(8) Length of tailpiece. The vertical distance from a trap to the fixture outlet shall not exceed 24 inches.
(9) Installation.
(i) Grade of trap arm. The piping between a 'P' trap and the fixture tee or the vented waste line shall be graded 1/4 inch per foot towards the vent and in no event shall have a slope greater than its diameter. The vent opening at fixture tees shall not be below the weir of the 'P' trap outlet.
(ii) Trap arm offset. The piping between the 'P' trap and vent may change direction or be offset horizontally with the equivalent of no more than 180 degrees total change in direction with a maximum of 90 degrees by any one fitting.
(iii) Concealed traps. Traps with mechanical joints shall be accessible for repair and inspection.
(iv) Removability of Traps, Etc. Traps shall be designed and installed so the 'U' bend is removable without removing the strainers from the fixture. Continuous waste and tail pieces which are permanently attached to the 'U' bend shall also be removable without removing the strainer from the fixture.
(b) Cleanout openings.
(1) Location of cleanout fittings.
(i) Cleanouts shall be installed if the drainage system cannot be cleaned through fixtures, drains, or vents. Cleanouts shall also be provided when fittings of more than 45 degrees are used to affect an offset except where long turn ells are used which provide sufficient 'sweep' for cleaning.
(ii) A full size cleanout shall be installed at the upper end of any section of drain piping which does not have the required minimum slope of 1/4 inch per foot grade.
(iii) A cleaning tool shall not be required to pass through more than 360 degrees of fittings, excluding removable 'P' traps, to reach any part of the drainage system.
(2) Access to cleanouts. Cleanouts shall be accessible through an unobstructed minimum clearance of 12 inches directly in front of the opening. Each cleanout fitting shall open in a direction opposite to the flow or at right angles to the pipe. Concealed cleanouts that are not provided with access covers shall be extended to a point above the floor or outside of the mobile home, with pipe and fittings installed, as required, for drainage piping without sags and pockets.
(3) Material. Plugs and caps shall be brass or approved or listed plastic, with screw pipe threads.
(4) Design. Cleanout plugs shall have raised heads except that plugs at floor level shall have counter-sunk slots.
280.607. Plumbing Fixtures.
(a) General Requirements.
(1) Quality of fixtures. Plumbing fixtures shall have smooth impervious surfaces, be free from defects and concealed fouling surfaces, be capable of resisting road shock and vibration, and shall conform in quality and design to listed standards. Fixtures shall be permanently marked with the manufacturer's name.
(2) Strainers. The waste outlet of all plumbing fixtures, other than toilets, shall be equipped with a drain fitting that will provide an adequate unobstructed waterway.
(3) Fixture connections. Fixture tailpieces and continuous wastes in exposed or accessible locations shall be not less than No. 20 Brown and Sharpe gage seamless drawn-brass tubing or other approved pipe or tubing materials. Inaccessible fixture connections shall be constructed according to the requirements for drainage piping. Each fixture tailpiece, continuous waste, or waste and overflow shall be not less than 1-1/2 inchees for sinks of two or more compartments, dishwashers, clothes washing machines, laundry tubs, bath tubs, and not less than 1-1/4 inches for lavoratories and single compartment sinks having a 2 inch maximum drain opening.
(4) Concealed connections. Concealed slip joint connections shall be provided with adequately sized unobstructed access panels and shal be accessible for inspection and repair.
(5) Directional fitting. An approved or listed 'Y' or other directional-type branch fitting shall be installed in every tailpiece or continuous waste that receives the discharge from food waste disposal units, dishwashing, or other force-discharge fixture or appliance. (See also 280.607(b)(4)(ii).)
(b) Fixtures.
(1) Spacing. All plumbing fixtures shall be so installed with regard to spacing as to be reasonably accessible for their intended use.
(2) Toilets. (i) Toilets shall be designed and manufactured according to approved or listed standards and shall be equipped with a water fluxhing device capable of adequately flushing and cleaning the bowl at each operation of the flushing mechanism. (ii) Toilet flushing devices shall be designed to replace the water seal in the bowl after each operation. Flush valves, flushometer valves, and ball cocks shall operate automatically to shut off at the end of each flush or when the tank is filled to operating capacity. (iii) Flush tanks shall be fitted with an overflow pipe large enough to prevent flooding at the maximum flow rate of the ball cock. Overflow pipes shall discharge into the toilet, through the tank. (iv) Toilets that have fouling surfaces that are not thoroughly washed at each discharge shall be prohibited. Any toilet that might permit the contents of the bowl to be siphoned back into the water system shall be prohibited. (v) Floor connection. Toilets shall be securely bolted to an approved flange or other approved fitting which is secured to the floor by means of corrosion-resistant screws. The bolts shall be of solid brass or other corrosion-resistant material and shall not be less than 1/4 inch in diameter. A watertight seal shall be made between the toilet and flange or other approved fitting by use of a gasket or sealing compound.
(3) Show compartment. (i) Each compartment stall shall be provided with an improved watertight receptor with sides and back extending at least 1 inch above the finished dam or threshold. In no case shall the depth of a shower receptor be less than 2 inches or more than 9 inches measured from the top of the finished dam or threshold to the top of the drain. The wall area shall be constructed of smooth, noncorrosive, and nonabsorbent waterproof materials to a height not less than 6 feet above the bathroom floor level. Such walls shall form a watertight joint with each other and with the bathtub, receptor or shower floor. The floor of the compartment shall slope uniformly to the drain at not less than one-fourth nor more than one-half inch per foot. (ii) The joint around the drain connection shall be made watertight by a flange, clamping ring, or other approved listed means. (iii) Shower doors and tub and shower enclosures shall be constructed so as to be waterprof and, if glazed, glazing shall comply with the Standard for Transparent Safety Glazing Material used in Buildings (ANSI Z97.1-1972). (iv) Prefabricated plumbing fixtures shall be approved or listed.
(4)Dishwashing machines. (i) Dishwashing machine shall not be directly connected to any waste piping, but shall discharge its waste through a fixed air gap installed above the machine. The drain connection from the air gap may connect to an individual trap, to a directional fitting installed in the sink tailpiece, or to the opening provided on the inlet side of a food waste disposal unit. (ii) Drain from a dishwashing machine shall not be connected to a sink tailpiece, continuous waste line, or trap on the discharge side of a food waste disposal unit.
(5) Clothes washing machines. (i) Clothes washing machines shall drain either into a properly vented trap, into a laundry tub tailpiece with watertight connections, into an open standpipe receptor, or over the rim of a laundry tub. (ii) Standpipes shall be 1-1/2 inches minimum nominal iron pipe size, 1- 1/2 inches diameter nominal brass tubing not less than No. 20 Brown and Sharpe gage, or 1-1/2 inches approved plastic materials. Receptors shall discharge into a vented trap or shall be connected to a laundry tub tailpiece by means of an approved or listed directional fitting. Each standpipe shall extend not less than 18 inches or more than 30 inches above its trap and shall terminate in an accessible location no lower than the top of clothes washing machine. A removable tightfitting cap or plug shall be installed on the standpipe when clothes washer is not provided. (iii) Clothes washing machine drain shall not be connected to the tailpiece, continuous waste, or trap of any sink or dishwashing machine.
(c) Installation.
(1) Access. Each plumbing fixture and standpipe receptor shall be located and installed in a manner to be accessible for usage, cleaning, repair and replacement.
(2) Alignment. Fixtures shall be set level and in true alighment with adjacent walls. Where practical, piping from fixtures shall extend to nearest wall.
(3) Brackets. Wall-hung fixtures shall be rigidly attached to walls by metal brackets or supports without any strain being transmitted to the piping connections. Flush tanks shall be securely fastened to toilets or to the wall with corrosive-resistant materials.
(4) Tub supports. Bathtub rims at wall shall be supported on metal hangers or on end-grain wood blocking attached to the wall unless otherwise recommended by the manufacturer of the tub.
280.608. Hangers and Supports.
(a) Stains and stresses. Piping in a plumbing system shall be installed without undue strains and stresses, and provision shall be made for expansion, contraction, and structural settlement.
(b) Piping supports. Piping shall be secured at sufficiently close intervals to keep the pipe in alignment and carry the weight of the pipe and contents. Unless otherwise stated in the standards for specific materials shown in the Table in 280.604(a), or unless specified by the pipe manufacturer, plastic drainage piping shall be supported at intervals not to exceed 4 feet and plastic water piping shall be supported at intervals not to exceed feet.
(c) Hangers and anchors.
(1) Hangers and anchors shall be of sufficient strength to support their proportional share of the pipe alignments and prevent rattling.

(2) Piping shall be securely attached to the structure by hangers, clamps, or brackets which provide protection against motion, vibration, road shock, or torque in the chassis.
(3) Hangers and straps supporting plastic pipe shall not compress, distort, cut or abrade the piping and shall allow free movement of the pipe.
280.609. Water Distribution System.
(a) Water supply.
(1) Supply piping. Piping systems shall be sized to provide an adequate quantity of water to each plumbing fixture at a flow rate sufficient to keep the fixture in a clean and sanitary condition without any danger of backflow or siphonage (See Table in 280.609(f)(1)). The manufacturer shall include in his written installation instructions that the mobile home has been designed for an inlet water pressure of 80 psi, and a statement that when the mobile home is to be installed in areas where the water pressure exceeds 80 psi, a pressure reducing valve should be installed.
(2) Hot water supply. Each mobile home equipped with a kitchen sink, and bathtub and/or shower shall be provided with a hot water supply system including a listed water heater.
(b) Water outlets and supply connections.
(1) Water connection. Each mobile home with a water distribution system shall be equipped with a 3/4-inch threaded inlet connection located within the rear half of the length of the mobile home. This connection shall be tagged or market 'Fresh Water Connection' (or 'Fresh Water Fill'). A matching cap or plug shall be provided to seal the water inlet when it is not in use, and shall be permanently attached to the mobile home or water supply piping. When a master cold water shutoff full flow valve is not installed on the main feeder line in an accessible location, the manufacturerer's installation instructions shall indicate that such a valve is to be installed in the water supply line adjacent to the home. When a mobile home includes expandable rooms or is composed of two or more units, fittings or connectors designed for such purpose shall be provided to connect any water piping. When not connected, the water piping shall be protected by means of matching threaded caps or plugs.
(2) Prohibited connections. (i) The installation of potable water supply piping or fixture or appliance connections shall be made in a manner to preclude the possibility of backflow. (ii) No part of any water system shall be connected to any drainage or vent piping.
(3) Rim outlets. The outlets of faucets, spouts, and similar devices shall be spaced at least 1 inch above the flood level of the fixture.
(4) Appliance connections. Water supplies connected to clothes washing or dishwashing machines shall be protected by an approved or listed fixed air gap provided within the appliance by the manufacturer.
(5) Flushometer valves or manually operated flush valves. An approved or listed vacuum breaker shall be installed and maintained in the water supply line on the discharge side of a toilet flushometer valve or manually operated flush valve. Vacuum breakers shall have a minimum clearance of 6 inches above the flood level of the fixture to the critical level mark unless otherwise permitted in their approval.
(6) Flush tanks. Toilet flush tanks shall be equipped with an approved or listed anti-siphon ball cock which shall be installed and maintained with its outlet or critical level mark not less than 1 inch above the full opening of the overflow pipe.

(c) Water heater safety devices.
(1) Relief valves. (i) all water heaters shall be installed with approved and listed fully automatic valve or valves designed to provide temperature and pressure relief. (ii) Any temperature relief valve or combined pressure and temperature relief valve installed for this purpose shall have the temperature sensing element immersed in the hottest water within the upper 6 inches of the tank. It shall be set to start relieving at a pressure of 150 psi or the rated working pressure to the tank whichever is lower and at or below a water temperature of 210° F. (iii) Relief valves shall be provided with full-sized drains, with cross sectional areas equivalent to that of the relief valve outlet, which shall be directed downward and discharge beneath the mobile home. Drain lines shall be of a material listed for hot water distribution and shall drain fully by gravity, shall not be trapped, and shall not have their outlets threaded, and the end of the drain shall be visible for inspection.
(d) Materials.
(1) Piping material. Water pipe shall be of standard weight brass, galvanized wrought iron, galvanized steel, Type K, L or M copper tubing, approved or listed plastic or other approved or listed material.
(i) Plastic Piping. All plastic water piping and fittings in mobile homes must be approved or listed for use with hot water.
(2) Fittngs. Appropriate fittings shall be used for all changes in size and where pipes are joined. The material and design of fittings shall conform to the type of piping used. Special consideration shall be given to prevent corrosion when dissimilar metals are joined. (i) Fittings for screw piping shall be standard weight galvanized iron for galvanized iron and steel pipe, and of brass for brass piping. They shall be installed where required for change in direction, reduction of size, or where pipes are joined together. (ii) Fittings for cooper tubing shall be cast brass or drawn copper (sweat-soldered) or shall be approved or listed fittings for the purpose intended.
(3) Prohibited material. Used piping materials shall not be permitted. Those pipe does, solder fluxes, oils, solvents, chemicals, or other substances that are toxic, corrosive, or otherwise detrimental to the water system shall not be used.
(e) Installation of piping.

(1) Minimum requirement. All piping equipment, appurtances, and devices shall be installed in workmanlike manner and shall conform with the provisions and intent of this standard.
(2) Screw pipe. Iron pipe-size brass or galavanized iron or steel pipe fittings shall be joined with approved or listed standard pipe threads fully engaged in the fittings. Pipe ends shall be reamed to the full bore of the pipe. Pipe-joint compound shall be insoluble in water, shall be nontoxic and shall be applied to male threads only.
(3) Solder fittings. Joints in copper water tube shall be made by the appropriate use of approved cast brass or wrought copper fittings, properly soldered together. The surface to be soldered shall be thoroughly cleaned bright mechanically. The joints shall be properly fluxed and made with approved solder.
(4) Flared fittings. A flaring tool shall be used to shape the ends of flared tubing to match the flare of fittings.
(5) Plastic pipe and fittings. Plastic pipe and and fittings shall be joined by installation methods recommended by the manufacturer or in accordance with provisions of a listed standard.
(f) Size of water supply piping.
(1) Minimum size. The size of water supply piping and branch lines shall not be less than sizes shown in the following table:

MINIMUM SIZE TUBING AND PIPE FOR WATER
DISTRIBUTION SYSTEMS
Tubing (Nominal)
Number of pipe iron
fixtures Diameter Outer diameter pipe size
(inches) (inches) (inches)
1 1/4 [FNa1] 3/8 1/2
2 3/8 1/2 1/2
3 1/2 5/8 1/2
4 1/2 5/8 1/2
5 or more 3/4 7/8 3/4



[FNa1] 6 ft. maximum length.
Exceptions to table: 3/8 inch nominal diameter or 1/2 inch OD minimum size for clothes washing or dishwashing machines, unless larger size is recommended by the fixture manufacturer. 1/2 inch nominal diameter or 5/8 inch OD minimum size for flushometer or metering type valves unless otherwise specified in their listing. No galvanized screw piping shall be less than 1/2 inch iron pipe size.
(2) Sizing procedures. Both hot and cold water piping systems shall be computed by the following method: (i) Size of branch. Start at the most remote outlet on any branch of the hot or cold water piping and progressively count towards the water service connection, computing the total number of fixtures supplied along each section of piping. Where branches are joined together, the number of fixtures on each branch shall be totalled so that no fixture is counted twice. Following down the lefthand column of the preceding Table a corresponding number of fixtures will be found. The required pipe or tubing size is indicated in the other columns on the same line. (ii) A water heater, food waste disposal unit, evaporative cooler or ice maker shall not be counted as a water-using fixture when computing pipe sizes.

(g) line valves. Valves, when installed in the water supply distribution system (except those immediately controlling one fixture supply) and when fully opened, shall have a cross-sectional area of the smallest orifice or opening, through which the water flows, at least equal to the cross-sectional area of the nominal size of the pipe in which the valve is installed.
280.610. Drainage Systems.
(a) General.
(1) Each fixture directly connected to the drainage system shall be installed with a water seal trap (280.606(a)).
(2) The drainage system shall be designed to provide an adequate circulation of air in all piping with no danger of siphonage, aspiration, or forcing of trap seals under conditions of ordinary use.
(b) Materials.
(1) Pipe. Drainage piping shall be standard weight steel, wrought iron, brass, copper tube DWV, listed plastic, cast iron, or other listed or approved materials.
(2) Fittings. Drainage fittings shall be recessed drainage pattern and smooth interior waterways of the same diameter as the piping and shall be of a material conforming to the type of piping used. Drainage fittings shall be designed to provide for a 1/4 inch per foot grade in horizontal piping. (i) Fittings for screw pipe shall be cast iron, malleable iron, brass, or listed plastic with standard pipe threads. (ii) Fittings for copper tubing shall be cast brass or wrought copper. (iii) Socket-type fittings for plastic piping shall comply with listed standards. (iv) Brass or bronze adaptor or wrought copper fittings shall be used to join copper tubing to threaded pipe.
(c) Drain outlets.
(1) Location of drain. Each mobile home shall have only one drain outlet which shall terminate in the rear half section.
(2) Clearance from drain outlet. The drain outlet shall be provided with a minimum clearance of 3 inches in any direction from all parts of the structure or appurtenances and with not less than 18 inches unrestricted clearance directly in front of the drain outlet.
(3) Drain connector. The drain connector shall not be smaller than the piping to which it is connected and shall be equipped with a water-tight cap or plug matching the drain outlet. The cap or plug shall be permanently attached to the mobile home or drain outlet.
(4) The drain outlet and drain connector shall not be less than 3 inches inside diameter.
(5) Preassembly of drain lines. Drain lines, provided by the manufacturer, located under the mobile home, designed to bring the drain system to one distribution point and which may be damaged in transit, must be designed for proper site assembly.
(d) Fixture connections. Drainage piping shall be provided with approved or listed inlet fittings for fixture connections, correctly located according to the size and type of fixture to be connected.
(1) Toilet connection. The drain connection for each toilet shall be 3 inches minimum inside diameter and shall be fitted with an iron, brass, or listed plastic floor flange adaptor ring securely screwed, soldered or otherwise permanently attached to the drain piping, in an approved manner and securely fastened to the floor.
(e) Size of drainage piping.
(1) Fixture load. Except as provided by 280.611(d)(2), drain pipe sizes shall be determined by the type of fixture and the total number connected to each drain. (i) A 1-1/2 inch minimum diameter piping shall be required for one and not more than three individually vented fixtures. (ii) A 2-inch minimum diameter piping shall be required for four or more fixtures individually vented. (iii) A 3-inch minimum diameter piping shall be required for toilets.
(f) Wet-vented drainage system. Plumbing fixture traps may connect into a wet-vented drainage system which shall be designed and installed to accommodate the passage of air and waste in the same pipe.
(1) Horizontal piping. All parts of a wet-vented drainage system, including the connected fixture drains, shall be horizontal except for wet-vented vertical risers which shall terminate with a 1-1/2 inch minimum diameter continuous vent. Where required by structural design, wet-vented drain piping may be offset vertically when other vented fixture drains or relief vents are connected to the drain piping at or below the vertical offsets.
(2) Size. A wet-vented drain shall be 2 inches minimum diameter and at least one pipe size larger than the largest connected trap or fixture drain. Not more than three fixtures may connect to a 2-inch diameter wet-vented drain system. (continued)