|(a) Vehicle fuel containers shall comply with the following specifications: (1) Fuel containers on vehicles other than school buses, mass transit, or other vehicles used in public transportation may be located within, below, or above the driver or passenger compartments, provided all connections to the containers are external to or sealed and vented from those compartments. The motor fuel containers installed on a special transit vehicle may be installed in the passenger compartment, provided all connections to the containers are external to or sealed and vented from those compartments. (2) Fuel supply components and containers shall be mounted in a location to minimize damage from collision. No part of a container or its appurtenances shall protrude beyond any part of the vehicle at the point of installation. (3) Fuel systems shall be installed with as much road or ground clearance as practicable, but not less than the minimum road or ground clearance of the vehicle when loaded to its gross vehicle weight rating. The minimum distance shall be measured from the lowest part of the fuel system. (4) No portion of a fuel supply container or container appurtenance shall be located ahead of the front axle or behind the rear bumper mounting face of a vehicle. Fuel container valves shall be protected from physical damage using the vehicle structure, valve protectors, or a suitable metal shield. (5) Fuel supply containers located less than eight inches from the exhaust system shall be shielded from direct heat. (6) Mountings shall minimize fretting corrosion between the fuel container and the mounting system by means of rubber insulators or other suitable means. (7) Fuel containers shall not be installed where they would adversely affect the driving characteristics of the vehicle. (8) Fuel containers on school buses or mass transit vehicles shall be installed on the underside of the vehicle, except as specified in subsection (c) of this section. Fuel containers on special transit vehicles shall be installed in a location which will not interfere with vehicle operation. (9) Fuel containers, appurtenances, and connections may be enclosed in a shroud-type structure, provided it is securely attached to the container and liquid-tight. The shroud access doors shall be secured in place by fasteners such as wing nuts or spring-loaded latches and shall not require the use of tools for removal. The use of locks on shroud access doors is prohibited. (b) Fuel supply containers shall be connected or mounted to comply with the following specifications: (1) Fuel supply container connections shall be external to or sealed and vented from the driver and passenger compartments or any space containing radio transmitters or other spark-producing equipment. (2) Container brackets shall be secured to the vehicle body, bed, or frame with bolts, lock washers and nuts, or self-locking nuts of a size and strength capable of withstanding a static force in any direction of eight times the weight of a full container for vehicles with gross vehicle weights of 19,500 pounds or less, and four times the weight of a full container for vehicles with gross vehicle weights of 19,501 pounds or more. Mounting brackets shall be marked with the manufacturer's name or logo. If self-locking nuts are installed, they shall not be reused once they are removed. Container mounting brackets shall prevent the container from jarring loose, slipping or rotating. (3) Fuel supply containers shall be secured in the mounting brackets by bolts, lock washers, and nuts, or self-locking nuts of a size and strength capable of withstanding a static force applied in any direction eight times the weight of the full container for vehicles with gross vehicle weights of 19,500 pounds or less, and four times the weight of a full container for vehicles with gross vehicle weights of 19,501 pounds or more. If self-locking nuts are installed, the nuts shall not be reused once they are removed. (4) The weight of the fuel container shall not be supported by the outlet, service valves, manifolds, or other fuel connections. (5) Containers shall be secured to a school bus, mass transit, or special transit vehicle frame excluding the floor by container fastenings or mounting brackets described in subsection (b) of this section. The fastenings or brackets shall be secured to the frame, backing plates, or other supporting structure without compromising the strength of that structure. (c) Roof-mounted containers are allowed if the vehicle was originally designed and manufactured to have roof-mounted containers or if the original manufacturer approves the design of the structure mounting. Vehicles shall not be modified to have roof-mounted containers. (d) Container markings shall be readable after a container is permanently installed on a vehicle. A portable lamp or mirror may be used to read markings. (e) Where an LNG container is substituted for the fuel container installed by the original manufacturer of the vehicle, whether or not that fuel container was for LNG, the LNG container shall either fit within the space in which the original fuel container was installed or comply with subsection (a) of this section. (f) If necessary, a plumbing chamber door shall be provided in the sidewall of the school bus, mass transit, or special transit vehicle to allow for easy access for filling or securing the service valve in the event of an emergency. The plumbing chamber door shall be hinged and latched, but not locked.