Fuel supply systems.

[Title 24 CFR 3280.704]
[Code of Federal Regulations (annual edition) - May 1, 2001 Edition]
[Title 24 - HOUSING AND URBAN DEVELOPMENT]
[Chapter Xx - OFFICE OF ASSISTANT SECRETARY FOR HOUSING--FEDERAL HOUSING]
[Part 3280 - MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS]
[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 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
only.
(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
container.
(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
capacity).
(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
open.
(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
connector.
(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
gage.
(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]