(a)
Reference publications.
Regulatory, statutory and informational publications may be obtained at the
addresses indicated.
(1)
ASME
Code. The American Society of Mechanical Engineers codes for boilers
and pressure vessels may be obtained from:
United Engineering Center
345 East 47th Street
New York, New York 10017.
(2)
ASTM Standards. The American
Society for Testing and Materials Standards may be purchased from:
American Society for Testing and Materials
1916 Race Street
Philadelphia, Pennsylvania 19103.
(3)
Bureau of Explosives.
Information on approval of safety devices by the Bureau of Explosives may be
obtained from:
Bureau of Explosives
Association of American Railroads
1920 L Street N..
Washington, D. C. 20036.
(4)
CGA Pamphlet. The
Compressed Gas Association pamphlet may be obtained from:
Compressed Gas Association, Inc.
500 Fifth Avenue
New York, New York 10036.
(5)
Code of Federal
Regulations. The
Code of Federal Regulations Title
49, "Transportation," Parts 100 to 199, may be purchased from:
Superintendent of Documents
United States Government Printing Office
Washington, D. C. 20402.
(6)
National Fire Protection
Association Pamphlet-
58. This pamphlet may be
obtained from:
NFPA
470 Atlantic Avenue
Boston, Massachusetts 02210.
(b)
Liquefied petroleum
gas. A fuel system using liquefied petroleum gas (LPG) shall meet the
following requirements in addition to those in subsection (e).
(1)
Fuel supply container.
An LPG fuel supply container shall be constructed, inspected and permanently
marked in accordance with the appropriate DOT regulation or ASMF
Code. A container constructed to the DOT regulations shall have a
minimum service pressure of 240 psi. A container constructed to the
ASME Code shall have a minimum working pressure of 250 psi.
That containers installed in enclosed space, including automobile trunks or
cabinets on vehicles and all engine fuel containers shall be constructed for at
least a 312.5 psig design pressure. A container shall be equipped with a fixed
liquid level gauge to indicate when the container is 79.8% full. A float gauge
does not meet the requirements for an outage valve or a fixed liquid level
gauge.
(2)
Two or more
containers. When two or more containers are used, a backflow check
valve shall be installed in each fuel line to prevent passing of fuel between
tanks during filling operations. A hydrostatic relief valve with a pressure
setting not lower than 350 psi nor higher than 500 psi shall be installed
between the backflow check valves and the fuel cutoff valve to the carburetor
and between two positive liquid shut-off points in the liquid piping and
hose.
(3)
Identification
markings. An LPG fuel supply container shall be permanently marked as
follows:
(i) Markings on the containers
constructed to the
ASTM Code shall include all the following:
(A) An official ASME Code U
symbol.
(B) The manufacturer's
name, initials or trademark.
(C)
The maximum allowable working pressure (psi at F).
(D) The serial number.
(E) The year built.
(F) The words "FOR LP GAS ONLY" in letters
not less than 1/4 inch high and visible after installation. Decals are
acceptable.
(ii)
Permanent markings on containers constructed to DOT regulations shall include:
(A) The letters "DOT" or "ICC" with the
appropriate specification and service pressure.
(B) The serial number.
(C) The year tested.
(D) The manufacturer's name, initials or
trademark, as registered with DOT.
(E) The words "FOR LP GAS ONLY" or "FOR LPG
ONLY" in letters not less than 1/4 inch high and visible after installation.
Decals and stencils are acceptable.
(iii) A container inlet and outlet except
those for relief valves and gauging devices shall be marked to designate
whether they communicate with vapor or liquid space.
(4)
Valves. A valve shall be
of a type that has been tested and listed by UL or by other nationally
recognized testing laboratories as meeting the UL requirements for LPG. All
valves shall be securely mounted and shielded or installed in a protected
location to prevent damage from vibration and unsecured objects.
(i)
Safety relief valves.
One or more spring-loaded internal safety valves shall be installed directly in
each fuel container in communication with the vapor space. The markings showing
"set to discharge pressure" shall be visible after the valves are installed in
the container. Safety relief valves for DOT fuel supply containers shall be
approved by the Bureau of Explosives, and the valve setting shall be as
required by the Bureau. The safety relief valve setting shall be as required by
the Bureau. The safety relief valve setting for ASME containers may not be less
than 100% nor more than 110% of the maximum allowable service pressure of the
container.
(A) Safety relief valves for ASME
fuel containers shall be constructed so as to discharge at not less than the
following rates before the pressure is in excess of 120% of the maximum
allowable working pressure of the container:
Tank surfacearea (sq.
ft.) |
Air flowrate (cfm) |
20 or less |
626 |
25 |
751 |
30 |
872 |
35 |
990 |
40 |
1,100 |
45 |
1,220 |
50 |
1,330 |
55 |
1,430 |
60 |
1,540 |
65 |
1,640 |
70 |
1,750 |
75 |
1,850 |
80 |
1,950 |
85 |
2,050 |
90 |
2,150 |
95 |
2,240 |
100 |
2,340 |
105 |
2,440 |
110 |
2,530 |
115 |
2,630 |
120 |
2,720 |
125 |
2,810 |
130 |
2,900 |
135 |
2,990 |
140 |
3,080 |
145 |
3,170 |
150 |
3,260 |
155 |
3,350 |
160 |
3,440 |
165 |
3,530 |
170 |
3,620 |
175 |
3,700 |
180 |
3,790 |
185 |
3,880 |
190 |
3,960 |
195 |
4,050 |
200 |
4,130 |
(B) Permanent markings on safety relief
valves in ASME containers shall include all of the following:
(I) The manufacturer's name, initials or
trademark.
(II) The manufacturer's
design or type numbers.
(III) The
discharge pressure (psi).
(IV) The
discharge capacity (cfm air at 60°F and 14.7 psia).
(V) The ASME or UL symbol.
(C) Permanent markings on safety
relief valves in DOT containers shall include all of the following:
(I) The manufacturer's name, initials, or
trademark.
(II) The catalog
number.
(III) The discharge
pressure (psi).
(IV) The discharge
capacity (cfm air at 60°F and 14.7 psia).
(ii)
Excess flow valve. An
internal excess flow valve, designed to close when maximum volume escapes
through the smallest connection in the supply line system, shall be installed
in every fuel supply container outlet except the relief valve or gauging device
outlets. The excess flow valve shall have a bypass not to exceed a Number 60
drill size opening to allow equalization of pressure.
(iii)
Check valve. Inlet
connections in the fuel supply container shall be fitted with an internal and
external check valve or an internal check valve with an adjacent or remote
manual shut-off valve. The inlet of the filling system shall be capped, except
when filling, to withstand the maximum service pressure of the container. A
container installed after January 1, 1973 shall be equipped for remote filling
exterior to the vehicle compartment with an internal and external check valve
installed in the container.
(iv)
Shut-off valve. A manually operated shut-off valve shall be
installed directly into the fuel supply container outlet connection serving the
supply line and shall be marked with the words, "SHUT-OFF VALVE." Decals or
stencils are acceptable.
(5)
Gauge. An LPG container
shall be equipped with a liquid volume gauge, which shall be designed and
installed as follows:
(i) The gauging device
shall be of a type that has been listed by UL or by other nationally recognized
testing laboratories as meeting the UL requirements for LPG.
(ii) The gauge shall be securely mounted and
shielded or installed in a protected location to prevent damage from excessive
vibration and unsecure objects.
(iii) A gauge that requires bleeding of the
product shall be bled to outside of the vehicle compartment and shall be
equipped with a bleeder valve. A restricting orifice not larger than Number 54
drill size shall be inside the fuel supply container.
(6)
Vaporizer and pressure-reducing
regulator. Devices which supply heat directly to the fuel container
shall be equipped with an automatic device to cut off the supply of heat before
the pressure in the container reaches 200 psig. A vaporizer shall be fabricated
of materials suitable for LPG service and resistant to any action of the LPG
under service conditions. Such vaporizers shall be designed for engine fuel
service and shall comply with the following:
(i) The vaporizer, any part of it, or any
devices used with it which may be subjected to container pressure shall have a
design pressure of at least 250 psig and shall be plainly and permanently
marked at a readily visible point:
(A) With
the design pressure of the fuel containing portion in psig.
(B) With the water capacity of the
fuel-containing portion in pounds.
(ii) A vaporizer shall not be equipped with
fusible plugs.
(iii) A vaporizer
shall have a valve or suitable plug located at or near the lowest portion of
the section occupied by the water or other heating liquid to permit
substantially complete drainage. The engine cooling system drain or water hoses
may serve this purpose, if effective.
(iv) Vaporizers and regulators shall be
securely fastened in position.
(v)
Engine exhaust gases may be used as a direct source of heat to vaporize the
fuel if the materials of construction of those parts of the vaporizer in
contact with the exhaust gases are resistant to corrosion from these gases and
if vaporizer system is designed to prevent excessive pressures.
(vi) Approved automatic pressure-reducing
equipment, properly secured, shall be installed between the fuel supply
container and the gas air mixer to regulate the pressure of the fuel delivered
to the gas-air mixture.
(vii) An
approved automatic shut-off valve shall be installed in the fuel system at some
point ahead of the inlet of the gas regulator, designed to prevent the flow of
fuel to the gas-air mixer when the engine is not running. Atmospheric type
regulators-zero governors-shall not be considered as automatic shut-off
valves.
(7)
Vents. A compartment in which an LPG container is installed
shall be vented to the atmosphere unless all piping and connectors are exterior
to the compartment. The vent or vents shall be installed at the lowest
practicable point of the compartment and shall have an open area totaling not
less than 3 square inches.
(8)
LPG hose for high pressure liquid or vapor use. The hose and
hose assemblies shall have a working pressure of not less than 350 psi and a
burst pressure of not less than 1750 psi. The hose shall be reinforced with
corrosion-resistant wire braid and shall be of a type that has been tested and
listed by UL or by other nationally recognized testing laboratories as meeting
the UL requirements for LPG. Hose shall have the following permanent
identification markings in letters and numerals at least 1/5 inch in height at
intervals of 24 inches or less:
(i) The
manufacturer's name, initials or trademark.
(ii) LPG or LP GAS.
(iii) The working pressure.
(iv) The burst pressure.
(9)
Hydrostatic relief
valve. Hydrostatic relief valves designed to relieve the hydrostatic
pressure that might develop shall be installed in sections of piping or hose
between closed shut-off valves and have a pressure setting of not less than 350
psig, or more than 500 psig.
(c)
Compressed natural gas.
A fuel system using compressed natural gas (CNG) shall meet the following
requirements in addition to those in subsection (e):
(1)
Fuel supply container. A
CNG fuel supply container shall be constructed and inspected in accordance with
DOT regulations and shall have a rated service pressure of not less than 2250
psi at 70°F. It shall not be filled beyond the working pressure stamped on
the tank and marked near the filler connection, corrected for the ambient
temperature at time of filling as prescribed by DOT.
(2)
Identification markings.
Each CNG fuel supply container shall have the following identification
markings:
(i) The letters "DOT" with the
appropriate specification and working pressure.
(ii) The serial number.
(iii) The year tested.
(iv) The manufacturer's name, initials, or
trademark.
(v) The words "FOR CNG
ONLY" in letters at least 1/4 inch high and visible after installation. Decals
or stencils are acceptable.
(3)
Shut-off valve. A
manually operated shut-off valve shall be in direct communication with the
container and shall be marked with the words, "SHUT-OFF VALVE." Decals or
stencils are acceptable. A normally closed automatic shut-off valve that is
held open by electrical current may be used in addition to a manual shut-off
valve and shall be marked with the words, "AUTOMATIC SHUT-OFF VALVE." The
automatic shut-off valve shall be wired so that it shuts off when the ignition
switch is in the off or accessory positions or when engine vacuum or oil
pressure is not present. A valve may not be used for CNG unless it has been
certified for that purpose by the manufacturer. The shut-off valve shall be
securely mounted and shielded or installed in a protected location to prevent
damage from vibration and unsecured objects.
(4)
Safety relief valve. One
or more safety relief devices shall be installed in the fuel supply container
in communication with the fuel and vented to the outside of the vehicle
compartment. A relief device shall be approved as to type, size, quantity and
location by the Bureau of Explosives and shall have the following permanent
identification markings:
(i) The
manufacturer's name, initials or trademark.
(ii) The flow capacity (cf).
(iii) The yield temperature rating
(F).
(5)
Gauges. Gauges used in CNG systems shall be designed and
installed as follows:
(i) A gauging device
shall be designed for the most severe pressure and temperature conditions to
which the devices may be subjected with a pressure safety factor of not less
than four.
(ii) Gauges shall be
securely mounted and shielded or installed in a protected location to prevent
damage from vibration and unsecured objects.
(6)
Pressure-reducing
regulators. An automatic pressure-reducing regulator shall be
installed in CNG systems to reduce container pressure to a valve consistent
with the working pressure required by the carburetor. Means shall be provided
to prevent malfunction due to refrigeration effects. Regulators shall be
installed so that their weight is not placed on or supported alone by the
attaching lines. Regulators shall be designed to a container's maximum working
pressure and temperature with a pressure safety factor of not less than
four.
(7)
Vents.
Every compartment in which a CNG container is installed shall be vented to the
atmosphere unless all piping and connections are exterior to the compartment or
vapor sealed and vented to the atmosphere. The vents shall be installed at the
highest practicable point of the compartment and shall have an open area
totalling not less than 3 square inches.
(d)
Liquefied natural gas. A
fuel system using liquefied gas (LNG) shall meet the following requirements in
addition to those in subsection (e).
(1)
Fuel supply container. An LNG fuel supply container shall be
constructed and inspected in accordance with
49 CFR
178.57 (relating to specification 4L; welded
cylinders insulated), specification 4L for welded insulated cylinders, with the
exception of 49 CFR
178.57-
13 and
178.57-
20 (relating to
pressure relief devices pressure control valves; and marking) and the report to
the Bureau of Explosives in 178.57-4(d) (relating to duties of inspector). Each
LNG container shall meet the following additional requirements:
(i) The unrelieved fuel pressure inside the
container shall not exceed 100 psi within a total 72-hour period consisting of
48 hours at 60°F and 12 hours at 90°F ambient temperatures when the
container has been filled with LNG conditioned at one atmosphere.
(ii) The container shall be equipped with a
liquid level gauging device and a dip tube to prevent filling beyond 90% by
volume at atmospheric pressure.
(iii) Each completed container, including its
supporting structure and valves, enclosures, and lines normally attached
thereto, shall have structural integrity to withstand damage from deceleration
and acceleration forces resulting from a 30 miles per hour front-end and
rear-end collision of the type of vehicle in which the container is installed.
A test or other means shall demonstrate that the container and its openings do
not rupture in such collisions.
(iv) Each LNG fuel supply container shall
have the following permanent identification markings:
(A) The numbers indicating the service
pressure.
(B) The serial
number.
(C) The manufacturer's
name, initials or trademark.
(D)
The inspector's mark.
(E) The date
tested.
(F) The words, "FOR LNG
ONLY" in letters not less than 1/4 inch high and visible after installation.
Decals or stencils are acceptable.
(v) An inlet and outlet except relief valves
and gauging devices shall be marked to designate whether they communicate with
vapor or liquid space.
(2)
Valves. A valve shall be
certified for LNG use by the manufacturer or certified for cryogenic service at
temperatures down to and including 320°F. A valve shall be securely mounted
and shall be shielded or installed in a protected location to prevent damage
from vibration and unsecured objects.
(i)
Safety relief valves. A container shall be equipped with one
or more safety relief valves. The safety relief valves shall be installed in a
line that communicates with the vapor space of the container. A safety relief
valve shall be installed between two shut-off valves in a supply line to
prevent a buildup of pressure between the valves in the off position. The
discharge pressure of safety relief valves shall not exceed 125% of the service
pressure of the container. A relief valve shall have sufficient capacity to
meet the requirement of either the Bureau of Explosives for approval of safety
relief valves or
NFPA 59(A) Appendix A and be capable of
preventing explosion of the normally charged cylinder when it is placed in a
fire. A relief valve shall have the following permanent identification
markings:
(A) The manufacturer's name,
initials, or trademark.
(B) The
catalog number.
(C) The discharge
pressure (psi).
(D) The discharge
capacity (cfm air at 60°F and 14.7 psia).
(ii)
Shut-off valves. One
manually operated shut-off valve shall be secured directly to the tank vapor
outlet with no intervening fitting other than the relief valve and shall be
marked with the words, "VAPOR SHUT-OFF VALVE." Another manually operated
shut-off valve shall be secured directly to the tank liquid outlet and shall be
marked with the words "LIQUID SHUT-OFF VALVE." Decals or stencils are
acceptable. Normally closed automatic shut-off valves that are held open by
electrical current may be used in lieu of manual shut-off valves at either the
tank vapor port or tank liquid port, or both. An automatic shut-off valve shall
be wired so it shuts off when the ignition switch is in the off and accessory
positions and when engine vacuum is not present.
(iii)
Control valve. A
positive shut-off control valve shall be installed in the fuel supply lines as
close to the containers as possible, automatically closing off and preventing
the flow of fuel to the carburetor when the ignition switch is off or in the
accessory position.
(3)
Gauges. Gauges used in LNG systems shall be designed and
installed as follows:
(i) A gauging device
shall be designed for the most severe pressure and temperature conditions to
which the devices may be subjected with a pressure safety factor of not less
than four.
(ii) The gauges shall be
securely mounted and shall be shielded or installed in a protected location to
prevent damage from vibration and unsecured objects.
(iii) A gauging device that requires bleeding
of the product shall be bled to the outside of the vehicle
compartment.
(4)
Pressure-reducing regulators. An LNG system shall be equipped
with one- or two-stage pressure-reducing regulators. The regulators shall be
installed so that their weight is not placed on or supported alone by the
attaching tubing or flexible lines.
(5)
Vents. A compartment in
which an LNG container is installed shall be vented to the atmosphere unless
all piping and connectors are exterior to the compartment. The vents shall be
installed at the highest practicable point of the compartment and shall have an
open area totalling not less than 3 square inches.
(e)
Installation. The
installation of liquefied petroleum gas, compressed natural gas or liquefied
natural gas fuel systems on motor vehicles shall be in accordance with the
following requirements:
(1)
Driver,
passenger and luggage compartments. A fuel supply container on a bus
may not be located in or above the passenger compartment, except that a fuel
supply container for compressed natural gas may be located above the driver and
passenger compartment. A fuel supply container on a vehicle shall be installed
and fitted so that no gas from fueling and gauging operations or from relief
valves can be released inside the driver, passenger or luggage
compartments.
(2)
Fuel
supply containers. A fuel supply container shall meet appropriate
requirements of the
ASME Code, the DOT regulations and this
chapter and shall be marked in accordance with subsections (b)-(d). A fuel
supply container shall comply with the following requirements:
(i) Each container and container cradle shall
be mounted in protected locations to minimize damage from collision.
(ii) To prevent damage from road hazards,
slippage, loosening or rotation, each container or cradle shall be secured to
the vehicle body, bed or frame by:
(A)
Attaching the bolts not less than 7/16 inch in diameter to at least four
securement points and, where the bolts pierce body metal but not the frame, by
reinforcing both sides of each securement point with metal plates at least 1/5
inch thick and 7 square inches in area.
(B) Using other means capable of withstanding
in any direction a static force of eight times the weight of the fully loaded
container.
(iii) Each
container in a cradle shall be secured to its cradle by means capable of
withstanding in any direction a static force of eight times the weight of the
fully loaded container.
(iv) No
portion of the container or container valves in communication with the liquid
or vapor shall be located behind the rear frame crossmember of the
vehicle.
(v) The weight of the
container shall not in any way be supported by outlets, valves, manifold or
other fuel connections.
(vi) No
part of the container shall be field welded. Only saddle plates, brackets or
other nonpressure parts that were provided and installed by the manufacturer of
the container may be field welded.
(vii) No container shall be repaired until
the contemplated repair has been authorized by a certified inspector. A DOT
container shall be repaired under DOT regulations and control. The replacement
of valves, fittings and accessories intended for the same purpose is not
considered a repair.
(viii) A
container located less than 8 inches from the engine or exhaust system shall be
shielded against direct heat.
(ix)
Where a container is installed above the driver or passenger compartment of a
vehicle, the container, its piping, fittings and valves shall be protected from
damage by:
(A) A guardrail or similar device
which is designated to absorb the impact of a collision with a stationary
object when the vehicle is moving either forward or backward at 8 kilometers
per hour (5 miles per hour). The guardrail, or similar device, shall be free of
projections that could damage the container, its valves and fittings.
(B) A shield designed to absorb impacts that
may occur during loading, unloading or use of the vehicle. The shield shall be
free of projections that could damage the container, its valves and
fittings.
(x) A part of a
fuel container or its appurtenances may not project beyond the sides and ends
or above the highest structural point of a vehicle.
(xi) The devices, bolts and nuts attaching a
fuel container to the outside of a vehicle shall have a corrosion resistant
coating.
(3)
Visibility of required markings. Markings of set-to-discharge
pressure for safety relief devices and working pressure of fuel supply
containers required by subsections (b), (c) and (d) shall be visible either
directly or by use of a mirror after installation. Remote filling inlets shall
be visibly marked with the lowest working pressure of any fuel supply container
in the system.
(4)
Discharge lines and outlets. All safety devices that may
discharge to the atmosphere shall be vented to the outside of the vehicle, and
all discharge lines and outlets shall be installed as follows:
(i) Lines shall be constructed of metal other
than aluminum and shall be of a size and so located and maintained as not to
restrict the maximum gas flow of the safety device. Flexible metallic lines
shall be used when necessary.
(ii)
The discharge line of a container installed inside a compartment shall extend
to the outside of the compartment.
(iii) Lines shall be located as far from the
exhaust outlet as is practicable and shall direct escaping gas upward within 45
degrees of the vertical. Escaping gas shall not impinge upon fuel supply
containers and shall not be directed into wheel wells, at other vehicles in
traffic, or at engine air intake inlets.
(iv) The discharge line from the safety
relief valve on all buses shall be directed upward and extended to the top of
the roof.
(v) Outlets shall be
protected by caps, covers or other means to keep water or dirt from collecting
in the lines. Protective devices shall not restrict the flow of gas.
(vi) Each line and its connectors shall
withstand the pressure caused by the discharge of vapor or liquid from a safety
device in fully open position.
(vii) A CNG container may be vented to the
outside of the vehicle with a flexible bag. The bag shall be constructed of
material that is nonflammable or self-extinguishing. The bag and attachments
shall be capable of withstanding an internal pressure producted by a flow rate
of 300 cfm with a safety factor of not less than four. The bag shall be
shielded or installed in a protected location to prevent damage from unsecured
objects and abrasion.
(5)
Manifolds. Manifolds connected to fuel containers shall be
supported to minimize vibration and shall be installed in a protected location
or shielded to prevent damage from unsecured objects.
(i) A manual shut-off valve shall be
installed in the outlet of the manifold and marked with the words "MANUAL
SHUT-OFF VALVE." Decals or stencils are acceptable.
(ii) A normally closed automatic shut-off
valve that is held open by electrical current may be used in lieu of a manual
shut-off valve and shall be marked with the words, "AUTOMATIC SHUT-OFF VALVE."
The automatic shut-off valve shall be wired so it shuts off when the ignition
switch is in the off or accessory positions and when engine vacuum is not
present.
(6)
Pipes, tubing, hose and fittings. Pipes, tubing, hose and
fittings shall meet the following requirements:
(i) Materials and assemblies shall be
designed for the widest pressure and temperature ranges to which they may be
subjected with a pressure safety factor of at least four.
(ii) Materials, including gasket and packing
material, shall be compatible with the fuel used in the system and its service
conditions. Aluminum pipe, tubing or fittings shall not be used between the
container and first-stage regulator. Copper tubing, when used, shall be
seamless and conform to ASTM B88 types K or L.
(iii) A pipe thread sealant impervious to the
action of the fuel used in the system shall be applied to all male pipe threads
prior to assembly. Only tin-silver (95% tin, 5% silver) or silver braze alloy
is permitted on sweat type joints of fittings.
(7)
Supply lines. Supply
lines passing through a panel shall be protected by grommets or similar
devices, which shall snugly fit both the supply lines and the holes in the
panel. Supply lines shall have a minimum clearance of 8 inches from the engine
exhaust system unless they are shielded from exhaust heat. Supply lines shall
be supported at least every 24 inches and shall be prevented from sagging.
Damaged lines shall be replaced, not repaired.
(8)
Automatic fuel supply
shut-off. An automatic fuel supply shut-off valve shall be installed
in a protected location adjacent to the manual shut-off valve on all buses and
shall be activated by engine vacuum or oil pressure.
(9)
Gaseous fuel cutoff.
Means shall be provided in the system to prevent the flow of gaseous fuel to
the carburetor when the ignition is in the off or accessory position or from
the carburetor when engine vacuum is not present.
(10)
Liquid fuel cutoff. A
dual fuel system using liquid and gaseous fuel shall have an approved automatic
shut-off valve installed in the liquid fuel line to the carburetor.
(11)
Bypass relief valve. A
bypass relief device shall be installed in the fuel pump or between the fuel
pump and the automatic shut-off valve in the liquid fuel line to the carburetor
on vehicles equipped with dual fuel systems for the use of gasoline and gaseous
fuel. The relief device need not be installed on fuel pumps containing a bypass
relief device as original equipment.
(12)
Engine exhaust outlet.
The engine exhaust system shall extend to the outer edge of the vehicle body or
bed on passenger cars, station wagons, house cars, pickup trucks with campers,
buses and delivery vans.
(13)
Electrical equipment. Radio transmitters, radio receivers,
electric motors or other electrical equipment except vehicle lamps and wiring
shall not be mounted in a compartment with fuel supply containers unless one of
the following conditions is met:
(i) All
piping and all connectors and valves on the fuel supply containers are exterior
to and sealed from the compartment containing electrical equipment.
(ii) All piping, connectors and valves within
the compartment are contained in a vapor-tight enclosure and vented to the
atmosphere exterior of the vehicle.
(iii) The electrical equipment is contained
in a vapor-tight enclosure that is vented to the atmosphere exterior of the
vehicle.
(14)
Road clearance. The fuel system including the fuel supply
container shall be installed with as much road clearance as practicable but not
less than the minimum road clearance of vehicle under maximum spring
deflection. The clearance shall be measured to the bottom of the container or
to the lowest fitting, support or attachment on the container or container
housing, whichever is lower.
(15)
Vehicle weight distribution. The total weight of the vehicle
with the fuel containers filled to capacity may not do one or more of the
following:
(i) Exceed the manufacturer's load
rating for an axle, wheel or tire, or gross weight limitations.
(ii) Create another unsafe load distribution
that would increase the risk of a hazardous operating condition, such as
vehicle rollover.
(iii) Adversely
effect the driving characteristics of the vehicle.