[Title 24 CFR 3280.704]
[Code of Federal Regulations (annual edition) - May 1, 2001 Edition]
[Subtitle B - Regulations Relating to Housing and Urban Development]
[Subpart H - Heating, Cooling and Fuel Burning Systems]
[Sec. 3280.704 - Fuel supply systems.]
[From the U.S. Government Printing Office]

24HOUSING AND URBAN DEVELOPMENT52001-05-012001-05-01falseFuel supply systems.3280.704Sec. 3280.704HOUSING AND URBAN DEVELOPMENTRegulations Relating to Housing and Urban DevelopmentOFFICE OF ASSISTANT SECRETARY FOR HOUSING--FEDERAL HOUSINGMANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDSHeating, Cooling and Fuel Burning Systems
Sec. 3280.704  Fuel supply systems.

    (a) LP--Gas system design and service line pressure. (1) Systems 
shall be of the vapor-withdrawal type.
    (2) Gas, at a pressure not over 14 inches water column (\1/2\ psi), 
shall be delivered from the system into the gas supply connection.
    (b) LP-gas containers--(1) Maximum capacity. No more than two 
containers having an individual water capacity of not more than 105 
pounds (approximately 45 pounds LP-gas capacity), shall be installed on 
or in a compartment of any manufactured home.
    (2) Construction of containers. Containers shall be constructed and 
marked in accordance with the specifications for LP-Gas Containers of 
the U.S. Department of Transportation (DOT) or the Rules for 
Construction of Pressure Vessels 1986, ASME Boiler and Pressure Vessel 
Code section VIII, Division 1 ASME Containers shall have a design 
pressure of at least 312.5 psig.
    (i) Container supply systems shall be arranged for vapor withdrawal 
    (ii) Container openings for vapor withdrawal shall be located in the 
vapor space when the container is in service or shall be provided with a 
suitable internal withdrawal tube which communicates with the vapor 
space on or near the highest point in the container when it is mounted 
in service position, with the vehicle on a level surface. Containers 
shall be permanently and legibly marked in a conspicuous manner on the 
outside to show the correct mounting position and the position of the 
service outlet connection. The method of mounting in place shall be such 
as to minimize the possibility of an incorrect positioning of the 
    (3) Location of LP-gas containers and systems. (i) LP-gas containers 
shall not be installed, nor shall provisions be made for installing or 
storing any LP-gas container, even temporarily, inside any manufactured 
home except for listed, completely self-contained hand torches, 
lanterns, or similar equipment with containers having a maximum water 
capacity of not more than 2\1/2\ pounds (approximately one pound LP-gas 
    (ii) Containers, control valves, and regulating equipment, when 
installed, shall be mounted on the ``A'' frame of the manufactured home, 
or installed in a compartment that is vaportight to the inside of the 
manufactured home and accessible only from the outside. The compartment 
shall be ventilated at top and bottom to facilitate diffusion of vapors. 
The compartment shall be ventilated with two vents having an aggregate 
area of not less than two percent of the floor area of the compartment 
and shall open unrestricted to the outside atmosphere. The required 
vents shall be equally distributed between the floor and ceiling of the 
compartment. If the lower vent is located in the access door or wall, 
the bottom edge of the vent shall be flush with the floor level of the 
compartment. The top vent shall be located in the access door or wall 
with the bottom of the vent not more than 12 inches below the ceiling 
level of the compartment. All vents shall have an unrestricted discharge 
to the outside atmosphere. Access doors or panels of compartments shall 
not be equipped with locks or require special tools or knowledge to 
    (iii) Permanent and removable fuel containers shall be securely 
mounted to prevent jarring loose, slipping or rotating and the 
fastenings shall be designed and constructed to withstand static loading 
in any direction equal to

[[Page 168]]

twice the weight of the tank and attachments when filled with fuel, 
using a safety factor of not less than four based on the ultimate 
strength of the material to be used.
    (4) LP-gas container valves and accessories. (i) Valves in the 
assembly of a two-cylinder system shall be arranged so that replacement 
of containers can be made without shutting off the flow of gas to the 
appliance(s). This provision is not to be construed as requiring an 
automatic change-over device.
    (ii) Shutoff valves on the containers shall be protected as follows, 
in transit, in storage, and while being moved into final utilization by 
setting into a recess of the container to prevent possibility of their 
being struck if container is dropped upon a flat surface, or by 
ventilated cap or collar, fastened to the container, capable of 
withstanding a blow from any direction equivalent to that of a 30-pound 
weight dropped 4 feet. Construction shall be such that the blow will not 
be transmitted to the valve.
    (iii) [Reserved]
    (iv) Regulators shall be connected directly to the container shutoff 
valve outlets or mounted securely by means of a support bracket and 
connected to the container shutoff valve or valves with listed high 
pressure connections. If the container is permanently mounted the 
connector shall be as required above or with a listed semi-rigid tubing 
    (5) LP-gas safety devices. (i) DOT containers shall be provided with 
safety relief devices as required by the regulations of the U.S. 
Department of Transportation. ASME containers shall be provided with 
relief valves in accordance with subsection 221 of the Standard for the 
Storage and Handling Liquefied Petroleum Gases, NFPA No. 58-1992. Safety 
relief valves shall have direct communication with the vapor space of 
the vessel.
    (ii) The delivery side of the gas pressure regulator shall be 
equipped with a safety relief device set to discharge at a pressure not 
less than two times and not more than three times the delivery pressure 
of the regulator.
    (iii) Systems mounted on the ``A'' frame assembly shall be so 
located that the discharge from the safety relief devices shall be into 
the open air and not less than three feet horizontally from any opening 
into the manufactured home below the level of such discharge.
    (iv) Safety relief valves located within liquefied petroleum gas 
container compartments may be less than three feet from openings 
provided the bottom vent of the compartment is at the same level or 
lower than the bottom of any opening into the vehicle, or the 
compartment is not located on the same wall plane as the opening(s) and 
is at least two feet horizontally from such openings.
    (6) LP-gas system enclosure and mounting. (i) Housings and 
enclosures shall be designed to provide proper ventilation at least 
equivalent to that specified in Sec. 3280.704(b)(3)(ii).
    (ii) Doors, hoods, domes, or portions of housings and enclosures 
required to be removed or opened for replacement of containers shall 
incorporate means for clamping them firmly in place and preventing them 
from working loose during transit.
    (iii) Provisions shall be incorporated in the assembly to hold the 
containers firmly in position and prevent their movement during transit.
    (iv) Containers shall be mounted on a substantial support or a base 
secured firmly to the vehicle chassis. Neither the container nor its 
support shall extend below the manufactured home frame.
    (c) Oil tanks--(1) Installation. Oil tanks and listed automatic 
pumps (oil lifters) installed for gravity flow of oil to heating 
equipment shall be installed so that the top of the tank is no higher 
than 8 feet above the appliance oil control and the bottom of the tank 
is not less than 18 inches above the appliance oil control.
    (2) Auxiliary oil storage tank. Oil supply tanks affixed to a 
manufactured home shall be so located as to require filling and draining 
from the outside and shall be in a place readily available for 
inspection. If the fuel supply tank is located in a compartment of a 
manufactured home, the compartment shall be ventilated at the bottom to 
permit diffusion of vapors and shall be insulated from the structural 
members of the body. Tanks so installed shall be

[[Page 169]]

provided with an outside fill and vent pipe and an approved liquid level 
    (3) Shutoff valve. A readily accessible, approved manual shutoff 
valve shall be installed at the outlet of an oil supply tank. The valve 
shall be installed to close against the supply.
    (4) Fuel oil filters. All oil tanks shall be equipped with an 
approved oil filter or strainer located downstream from the tank shutoff 
valve. The fuel oil filter or strainer shall contain a sump with a drain 
for the entrapment of water.

[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, 
as amended at 47 FR 49390, Nov. 1, 1982; 52 FR 4587, Feb. 12, 1987; 58 
FR 55016, Oct. 25, 1993]