(a) The following subsections, (b) and (c) of this section, inclusive, apply to the design, construction, and assembly of motor fuel containers and vaporizers mounted on motor vehicles such as:

1. (1) Automobiles;
2. (2) Trucks;
3. (3) Buses;
4. (4) Pickups;
5. (5) Forklifts; and
6. (6) Other type vehicles or mobile equipment.

(b) Fuel tanks.

1. (1)

   1. (A) Fuel containers mounted on trucks, tractors, and all other mobile or portable equipment (except automobiles, buses, industrial and forklift trucks) shall be constructed:

(i) In compliance with 15 CAR § 270-111(a); and

1. (ii) For a safe working pressure of not less than two hundred fifty pounds per square inch gauge (250 psig).

   1. (B) Motor fuel containers mounted or installed on automobiles, industrial and forklift trucks, and all buses having a seating or carrying capacity of six (6) or more passengers, shall be designed for a safe working pressure of not less than three hundred twelve pounds per square inch gauge (312 psig).

   2. (C)

      1. (i) The use of liquefied petroleum gas for the direct heating or air conditioning of any automobile, truck cab, bus, etc., is strictly prohibited.
      2. (ii) It is not the intent of this section to prevent the use of liquefied petroleum gas for the purpose of heating or cooling the cargo portion of a:

(b) (b) Transport; or

1. (c) (c) Trailer.

   1. (D)

      1. (i) All motor fuel containers mounted on motor homes, campers, or similar type vehicles shall be used exclusively for the supply of liquefied petroleum gas to the engine of the vehicle upon which it is mounted or installed.
      2. (ii) There shall be no other attachments or lines extending from the container, nor shall said container be used for the supply of fuel to any appliance within the vehicle.
      3. (iii) All gas-consuming appliances installed for use by the vehicle shall be supplied fuel from a separate container designed and constructed for vapor service only.

   2. (E)

      1. (i) Each container for installation or mounting on motor vehicles shall be:

(b) (b) Installed or mounted in accordance with the manufacturer’s specifications or requirements.

1. (ii) Each set of mounting brackets not permanently attached to the container shall bear the manufacturer's name, initials, mark, or other identifying device, permanently and legibly stamped upon each bracket indicating the brackets are intended for use with said container.

2. (2)

   1. (A) Motor fuel containers shall be equipped with safety relief valve, filler valve, shutoff valve, fixed outage gauge, and a liquid level gauge of one (1) of the following types:

      1. (i) Slip tube;
      2. (ii) Rotary; or
      3. (iii) Visible float.
   2. (B) If the container is to be equipped with both vapor and liquid outlets, the liquid outlet shall be marked as outlined in 15 CAR § 270-111(g).
   3. (C) All openings exceeding number 54 drill size, except safety relief valves, shall be equipped with an excess flow check valve.
   4. (D) All motor fuel containers for installation on buses shall have an automatic device incorporated into the fill connection to prevent overfilling of the container.
3. (3) No single fuel container used exclusively for supplying fuel to the motor of a delivery truck, transport, or bus shall exceed one hundred (100) water gallon capacity.
4. (4) No single fuel container used exclusively for supplying fuel to the motor of a passenger automobile shall exceed thirty-five (35) water gallon capacity.
5. (5) The use of a DOT cylinder or container for a fuel tank on mobile equipment operating over public thoroughfare is prohibited.

6. (6)

   1. (A) Fuel may be used from the cargo containers of a delivery truck, but not from the cargo containers on trailers or semitrailers.
   2. (B) Where fuel tanks, commonly referred to as saddle tanks, are used to supply fuel to the engine, there shall be no piping, hose, or other connection between the cargo container and the saddle tanks while the unit is in operation.

7. (7)

   1. (A) Fuel container shall be located in a place and in a manner such as to minimize the possibility of mechanical injury.
   2. (B) Containers located in the rear of trucks, cars, and buses, when protected by substantial bumpers, will be considered in conformance with this requirement.

8. (8)

   1. (A) Fuel containers shall be installed with as much clearance as practicable but never less than the minimum normal road clearance of the vehicle under maximum load conditions.
   2. (B) This minimum clearance shall be to the bottom of the container or to the lowest fitting on the container or housing, whichever is lower.
9. (9) Fuel containers may be permanently installed or may be removable, provided proper anchorage is assured.

10. (10)

    1. (A) Fuel containers shall be adequately secured to the vehicle to prevent jarring-loose, slipping, or rotating, and the mounting attachments shall be designed and constructed to withstand without deformation static loading in any direction equal to four (4) times the weight of the container filled with fuel.
    2. (B) Field welding where necessary shall be made only on saddle plates, lugs, or brackets originally attached to the container by the manufacturer.
11. (11) Fuel containers from which gas is to be withdrawn only in gaseous phase shall be installed and equipped with suitable valves and connections to prevent the accidental withdrawal of liquid.

12. (12) Valves and connections shall:

    1. (A) Have a rated working pressure of at least two hundred fifty pounds per square inch gauge (250 psig); and
    2. (B) Be of a suitable type for liquefied petroleum gas service.

13. (13)

    1. (A) The filling connection shall be fitted with an approved:

       1. (i) Combination back-pressure check valve and excess flow valve;
       2. (ii) One (1) double or two (2) single back-pressure check valves; or
       3. (iii) A positive shutoff valve, in conjunction with either an internal back-pressure check valve or an internal excess flow valve.
    2. (B) Main shutoff valve adjacent to the tank on liquid and vapor lines shall be accessible at all times.
14. (14) All connections to fuel containers, having openings for the flow of gas in excess of a number 54 drill size, except safety relief device connections, shall be equipped with approved automatic excess flow valve or their equivalent, except in the case of filling connections, which may be equipped with an approved automatic back-pressure check valve, to prevent discharge of contents in case connections are broken.

15. (15)

    1. (A) All piping from the fuel container to first stage regulator shall be:

       1. (i) Type K or L seamless copper tubing, its equivalent, or stainless steel wire braid hose with a minimum bursting pressure of one thousand seven hundred fifty pounds per square inch gauge (1,750 psig) (thirty-five pounds per square inch gauge (35 psig) working pressure); and
       2. (ii) Properly marked at not more than five-foot intervals.

    2. (B) Fuel lines shall be adequately supported and protected:

       1. (i) Against mechanical injury, vibration, strain, or wear; and
       2. (ii) To eliminate any working loose while in transit.
    3. (C) Where fuel line passes through the bed, truck, floor, or other metallic or structural portion of a motor vehicle, a bulkhead, rubber grommet, or other type fitting shall be used to prevent the possibility of chafing or other wear to the line.

16. (16)

    1. (A) Fuel lines shall not be installed in close proximity to sources of extreme heat unless adequately insulated.
    2. (B) Fuel lines installed on automobiles and buses shall be of stainless steel wire braid hose, meeting the requirements of subdivision (b)(15) of this section.
    3. (C) Hydrostatic relief valve designed to relieve the hydrostatic pressure should be installed in the fuel line where liquid fuel may be isolated or trapped between closed shutoff valves.

    4. (D) The start-to-discharge pressure shall not be:

       1. (i) Less than four hundred pounds per square inch gauge (400 psig); or
       2. (ii) More than five hundred pounds per square inch gauge (500 psig).

17. (17)

    1. (A) Motor fuel containers installed on passenger-carrying vehicles (except buses) shall be installed and fitted so that no gas from fueling and gauging operations, or from relief valves, can be released inside the passenger or luggage compartment, or within any space containing radio equipment.
    2. (B) The discharge from relief valve shall be piped to the outside and directed upwards in such a manner as to minimize the possibility of gas impingement on other vehicles or objects.

    3. (C)

       1. (i) Relief valve discharge on containers installed on buses and other type vehicles having skirting, panels, or similar design, shall be located in such manner as to minimize the possibility of impingement of escaping gas upon:

(b) (b) Vehicle parts; or

1. (c) (c) Other vehicles or objects.

   1. (ii) The relief valve discharge shall terminate outside the skirting or paneling of the unit in an upward direction.

   2. (D)

      1. (i) Safety relief valve discharge lines shall be metallic (other than aluminum tubing) and shall be sized, located, and secured in such manner as to not obstruct or restrict discharge capacity.
      2. (ii) Flexible metal hose or tubing, when used, shall be able to withstand the pressure from the relief valve discharge when the valve is in the full open position.
      3. (iii) The end of the discharge piping shall be equipped with a loose-fitting rain cap or other suitable type device to eliminate the entrance of water, dirt, or other foreign matter into the piping or valve.
      4. (iv) The cap or device shall remain in place except when the relief valve is in operation and shall not interfere or restrict full flow or function of the valve.

2. (18)

   1. (A) Containers that are to be used for mobile fuel purposes, regardless of size, shall be equipped with individual fittings.

   2. (B) The use of domestic compact head is prohibited.

      1. (c) Vaporizers — Motor fuel.

3. (1) All vaporizers used in connection with liquefied petroleum gas as a fuel shall have their correctness as to design, construction, and performance certified as follows:

   1. (A) Tested and listed as approved by Underwriters Laboratories, Inc.; or
   2. (B) Approved by test by any other competent laboratory recognized by the Liquefied Petroleum Gas Board.
4. (2) Vaporizers and any part thereof, and other carbureting devices, which may be subjected to full container pressure shall have a designated working pressure of at least two hundred fifty pounds per square inch gauge (250 psig).
5. (3) Each vaporizer shall have a valve or suitable drain plug located at or near the lowest portion of the section occupied by the water or other heating medium, which will substantially complete draining of the vaporizer.
6. (4) Vaporizers shall be securely fastened to the vehicle body or to the engine in such manner as to minimize the possibility of their becoming loosened by vibration or impact.

7. (5) Each vaporizer shall be permanently marked at a visible point as follows:

   1. (A) With the designed working pressure in pounds per square inch; and
   2. (B) With the water capacity of the gas-containing portion of the vaporizer in pounds.
8. (6) Approved automatic pressure reducing equipment shall be installed between the fuel supply container and gas air mixer for the purpose of reducing the pressure of the liquefied gas coming to the gas air mixer.

9. (7)

   1. (A) An approved automatic shutoff 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.
   2. (B) Automatic type regulators (zero governors) shall not be considered as automatic shutoff valves except for portable engines of twelve (12) horsepower or less with magneto ignition and used exclusively outdoors.