California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 1 - Unfired Pressure Vessel Safety Orders › Article 7 - Compressed and Liquefied Natural Gas System › Section 544 - Installation of Fuel Tanks or Cylinders for Motor Vehicles and Industrial Trucks

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
NOTE: This Section does not apply to those vehicles under
						the control of the Department of Highway Patrol, except subsections (p), (q),
						and (r).
(a) Motor fuel tanks or
					 cylinders shall be located in a place and in a manner to minimize the
					 possibility of physical damage.
(b)
					 Motor fuel tanks or cylinders for passenger type vehicles may be located in the
					 trunk compartment provided the trunk compartment is properly ventilated and the
					 safety relief valve discharge is piped outside. When a motor fuel tank or
					 cylinder is installed inside a trunk or other compartment, positive means shall
					 be provided to prevent leakage of natural gas into the passenger or driver's
					 compartment. Vehicle tanks or cylinders that have their connections or
					 appurtenances in the end shall have as much space as possible for connecting
					 the required flexible metal hose or tubing and for operating the manually
					 operated shutoff valve.
(c) If
					 radio transmitting or receiving equipment is located in the same compartment as
					 the fuel tank or cylinder such transmitting or receiving equipment shall be
					 enclosed in a vapor-tight compartment or otherwise protected from escaping
					 fuel, unless the radio equipment is approved for use in a Class 1, Division 1,
					 Group D location.
(d) For
					 passenger-carrying or other commercial vehicles, motor fuel tanks or cylinders
					 and their valves and appurtenances may be installed in a recess which is
					 vapor-tight to the inside of the vehicle and accessible from and vented to the
					 outside.
(e) Valves, fittings and
					 appurtenances containing natural gas shall not be located in the passenger or
					 driver compartment unless all such valves fittings and appurtenances are
					 positively sealed off from and vented to a point outside the passenger or
					 driver compartment.
(f) Each motor
					 fuel tank shall be provided with a manually operated shutoff valve screwed
					 directly into the tank connection. The manual shutoff valve shall be readily
					 accessible or an electrically operated valve shall be installed in the line
					 next to the manual valve. The manual shutoff valve shall be legibly labeled
					 "Shutoff Valve." In installations of multiple cylinder manifolding, there shall
					 also be a master shut-off valve either electrically or manually operated and
					 located downstream from but as close as possible to the last cylinder in the
					 series. In these cases there shall be a label indicating "Shut-off Valve" at
					 the master valve and the individual tank valves need not be labeled.
(g) Motor fuel tanks or cylinders shall be
					 installed in such a manner that the bottom of the vessel and/or any connection
					 thereto shall not be lower than the lowest horizontal axle when the vehicle is
					 fully loaded.
(h) Vents from
					 control devices shall discharge outside the trunk compartment or other confined
					 space.
(i) Motor fuel tanks or
					 cylinders shall be secured in a manner to prevent jarring loose, slipping or
					 rotating of the tanks. Such fastening shall be designed to withstand loadings
					 in any direction equal to the filled weight of the tank with a factor of safety
					 of at least 8. Motor fuel tanks or cylinders shall not be fastened directly to
					 the gasoline fuel tank. Compensation shall be made for the added weight by
					 proper design or redesign of the vehicle suspension system when the loaded
					 weight of the vehicle exceeds the manufacturer's maximum
					 specifications.
(j) Manifolded
					 motor fuel tanks or cylinders shall be supported and held together as a unit by
					 structurally adequate means. Manifolded branch lines shall be sufficiently
					 flexible to prevent damage to the lines, valves and tanks due to vibration,
					 expansion or contraction. Valves and appurtenances shall be protected from
					 mechanical damage either by being located in recessed wells or by adequate
					 guarding.
(k) All connecting parts
					 of the fuel system shall be installed in such a manner as to prevent abrasion,
					 vibration or fatigue and physical damage.
(l) Field welding, where necessary, shall be
					 made only on saddle plates, brackets or other non-pressure parts that were
					 provided and installed by the manufacturer of the tank or cylinder. There shall
					 be no welding on the vessel shell or heads other than that by the manufacturer
					 unless the welding is acceptable to the authorized inspector.
(m) The connection between the motor fuel
					 tanks or cylinders and the reducing valves, vaporizer or other devices used to
					 reduce the pressure to that needed for carburetion shall be of flexible
					 metallic tubing, wire-braided hose or equivalent with a factor of safety of not
					 less than 5 for the most severe pressure and temperature design conditions.
					 There shall be as few connections and fittings as practicable.
(n) Automatic pressure reducing equipment
					 shall be used for the purpose of reducing the pressure of natural gas to the
					 carburetor, which shall not exceed 5 psi. Positive means shall be provided to
					 prevent malfunction due to refrigeration effects. There shall be a device in
					 the fuel supply system which will automatically stop the flow of fuel when the
					 engine is not running.
(o) Each
					 driver shall be trained in the safe use of this fuel system and be provided
					 with a set of operating instructions. The driver's employer shall be
					 responsible to see that this is done.
(p) While the natural gas motor fuel tank or
					 cylinder is being filled, the vehicle parking or emergency brakes shall be set
					 and the motor shut off. All transfer operations shall be supervised by an
					 attendant familiar with the transfer operation. The attendant may be considered
					 familiar with the transfer operation after he has been provided with a set of
					 instructions and has performed the transfer operation at least through 3 full
					 cycles under supervision. Where LNG motor fuel tanks or cylinders are being
					 filled, the attendant shall remain at the controls necessary to stop the
					 transfer operation.
(q) Fill
					 connections for motor fuel tanks or cylinders shall have at least one back-flow
					 check valve or device. Quick disconnect couplings may be used provided they are
					 designed for the most severe pressure and temperature conditions with a factor
					 of safety of at least 5 and provided they are leak-tight in the connected and
					 disconnected shutoff conditions. These couplings shall not be used in lieu of
					 any required manually operated shutoff valves.
(r)
When motor vehicles are to be
					 parked within buildings, adequate provisions shall be made such as roof
					 ventilation to prevent gases lighter than air from being trapped at ceiling
					 level. No source of ignition, electrical or otherwise, shall be permitted at
					 those levels. (Title 24, T8-544(r))
1.
						Amendment filed 4-1-77; effective thirtieth day thereafter (Register 77, No.
						14).