Each LP-Gas system uses approved regulators, containers, connectors, valves and manifold valve assemblies; cylinders meet DOT specification marking under 49 CFR Part 178; welding on containers is prohibited. Valves and fittings connected directly to containers are rated for at least 250 psig and suitable for LP-Gas, and connections other than relief, gauging and plugged openings have shutoff valves close to the container. Every container and vaporizer has approved safety relief devices venting freely to the open air at least 5 feet horizontally from any building opening below the discharge, with no shutoff valve between the relief device and the container unless full relief capacity is always preserved, and relief devices and regulator vents at least 5 feet from sealed-combustion air openings and mechanical ventilation intakes. Vehicle fuel containers are filled from bulk storage at least 10 feet from masonry-walled buildings or 25 feet from other buildings and in any case 25 feet from building openings; portable or skid containers are filled at least 50 feet from the nearest building. Appliances are approved, and appliances built for another gas are used only after proper conversion and testing. Outside, containers stand upright on firm foundations or are firmly secured, with flexible connections against settling. Inside buildings, containers may be used only when portable use is operationally necessary and outside location impracticable, subject to: excess flow valves for containers over 2 1/2 pounds water capacity; regulators connected to container valves or manifolds rated for 250 psig; valve protection on containers over 50 pounds water capacity; no aluminum piping; listed hose rated for 250 psig and kept short; portable heaters with automatic flame-failure shutoff (and, above 50,000 BTU per hour, a proved pilot or electric ignition; heaters under 7,500 BTU per hour on containers of 2 1/2 pounds or less are exempt); no use of valves or piping as heater supports; protection from heat and damage; containers on firm, substantially level ground and secured upright where necessary; a maximum individual container of 245 pounds water capacity; heaters at least 6 feet from containers and blower or radiant heaters not aimed at a container within 20 feet; heater-container units on the same unpartitioned floor 20 feet apart; and manifolded containers no more than 735 pounds water capacity with manifolds 20 feet apart. Multiple-container systems allow changeover without stopping gas flow, heaters have approved regulators and cylinder connectors have excess flow valves, and regulators are rigidly secured and protected. LP-Gas may not be stored in buildings; outside storage is kept at the Table F-3 distances from buildings by quantity (none for 500 pounds or less up to 25 feet above 10,000 pounds), ventilated and protected against tampering, with at least one 20-B:C extinguisher. Non-DOT storage containers meet the Table F-31 design pressures, skid tanks meet the placement and support conditions, field welding is only on manufacturer-applied saddle plates or brackets, containers are marked to ANSI Z48.1-1954 where other gases share the area, and systems are protected where vehicle damage is possible.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.