1. (a) Fuel supply cylinders 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 compartment, provided all connections to the cylinders are external to, or sealed and vented from those compartments.
2. (b) Fuel supply cylinders on school buses, mass transit, and other public transportation vehicles shall not be located above or within the driver or passenger compartment. The motor fuel containers installed on a special transit vehicle may be installed in the passenger compartment, provided it complies with subsection (a) of this section.
3. (c) Each fuel supply cylinder shall be mounted in a location to minimize damage from collision. No part of a cylinder or its appurtenances shall protrude beyond the sides or top of the vehicle at the point where it is installed.
4. (d) The fuel system shall be installed with as much road clearance as practical, but not less than the minimum road clearance of the vehicle when loaded to its gross vehicle weight rating. This minimum clearance shall be measured from the lowest part of the fuel system.
5. (e) No portion of a fuel supply cylinder or cylinder appurtenance shall be located ahead of the front axle or behind the rear bumper mounting face of a vehicle. Cylinder valves shall be protected from physical damage using the vehicle structure, valve protectors, or a suitable metal shield.
6. (f) Each cylinder bracket 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 fully pressurized cylinder. The cylinder bracket shall be designed and manufactured by a cylinder manufacturer. Each specific mounting bracket manufactured on or after January 1, 1994, must have the manufacturer's name or logo on it in order to properly identify the bracket manufacturer. If self-locking nuts are installed, such nuts shall not be reused once they are removed. The container mounting brackets shall prevent the container from jarring loose, slipping, or rotating.
7. (g) Each fuel supply cylinder 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 fully pressurized cylinder. If self-locking nuts are installed, such nuts shall not be reused once they are removed.
8. (h) The cylinder weight shall not be supported by the outlet, service valves, manifolds, or other fuel connections.
9. (i) Fuel supply cylinders located less than eight inches from the exhaust system shall be shielded against direct heat.
10. (j) The mounting system shall minimize fretting corrosion between the cylinder and the mounting system by means of rubber insulators or other suitable means.
11. (k) Fuel supply cylinders shall not be installed so as to adversely affect the driving characteristics of the vehicle.
12. (l) Containers shall be secured to a school bus, mass transit, or special transit vehicle frame (not the floor) by container fastenings or mounting brackets described in subsection (f) of this section. The fastenings or brackets must be secured to the frame or securely mounted to a supporting structure so as not to compromise the strength of that structure (i.e., backing plates or other acceptable means may be used to accomplish this purpose). Container(s) which are currently installed on school buses or mass transit vehicles by means of strap mounting brackets may continue to be used.
13. (m) The motor fuel container(s) installed on a school bus or mass transit vehicle shall be installed on the underside of the vehicle.
14. (n) If necessary, a plumbing chamber door shall be provided in the sidewall of the school bus, mass transit, or special transit vehicle to allow 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.

Source Note:The provisions of this §13.133 adopted to be effective November 15, 1990, 15 TexReg 5945; amended to be effective October 15, 1993, 18 TexReg 6459.