1.1 These requirements cover shut-off valves, with or without relief valve, that are for use on cylinders that comply with the specifications and charging and maintenance regulations of the U.S. Department of Transportation (DOT) or the corresponding specifications and regulations of Transport Canada (TC).

1.2 Valves covered by these requirements are for use on DOT or TC cylinders used for flow of gas into and out of the cylinder, in applications such as, but not limited to, automotive, medical, or industrial systems, vehicles, facilities, or providing fuel to buildings or appliances, and as covered in the following standards:

1. a) Liquefied Petroleum Gas Code, NFPA 58;

2. b) Design and Installation of Oxygen-Fuel Gas Systems for Welding, Cutting, and Allied Processes, NFPA 51;

3. c) Safety Requirements for the Storage and Handling of Anhydrous Ammonia – See CGA G-2.1, CGA K61.1;

4. d) Safety in Welding, Cutting, and Allied Processes, AWS Z49.1; and

5. e) Health Care Facilities, NFPA 99.

1.3 Gas-line shut-off valves, other shutoff valves used on ASME containers, filler valves, excess flow check valves, for use with liquefied petroleum gases or anhydrous ammonia are covered by the requirements in the Standard for Flow Control Valves for Anhydrous Ammonia and LP-Gas, UL 125.

1.4 Gas-line shut-off valves for use with flammable gases are covered by the requirements in the Standard for Valves for Flammable Fluids, UL 842.

1.5 Gas-line shutoff valves for compressed gases, other than those described in 3 and 4, are covered by the requirements in Outline of Investigation for Compressed Gas Shutoff Valves, UL 1477.

1.6 The type of refrigerant used in the system shall comply with the Standard for Refrigerants, UL 2182.