UL 569-2013 pdf download – Pigtails and Flexible Hose Connectors for LP-Gas.
7 Materials for Flexible Hose Connectors 7.1 The hose used in the construction of a flexible hose connector shall be provided with a reinforced synthetic-rubber inner tube or liner of the oil-resistant type. A rubber cover is not required if the outer braid is impregnated with a rubber cement or compound. A tube or a cover shall be smooth, of uniform thickness, free from pitting, blisters, or other imperfections. Intentional pricking of a cover shall not be considered an imperfection. This requirement does not exclude the use of a corrugated cover. 7.2 Aluminum shall not be used in combination with copper or a copper alloy. 7.3 A part made of drawn-brass or machined from brass rod, containing more than 1 5 percent zinc shall withstand, without cracking, the Moist Ammonia-Air Stress Cracking Test, Section 23. 7.4 End-connecting fittings shall be of corrosion resistant metal or of steel provided with a protective coating having corrosion-resistant qualities at least equivalent to those of the coatings specified in 7.5. 7.5 Cadmium plating shall be not less than 0.0003 inch (0.008 mm) thick, and zinc plating shall be not less than 0.0005 inch (0.01 3 mm) thick. However, on parts where threads constitute the major portion of the area, the cadmium or zinc plating shall be not less than 0.0001 5 inch (0.0038 mm) thick.
8 End Connecting Fittings 8.1 Each end of a connector shall be provided with a connecting fitting consistent with the service for which the connector is designed. 8.2 A standard LP-Gas cylinder valve connecting fitting shall comply with the Standard for Compressed-Gas Cylinder Valve Outlet and Inlet Connections, ANSI/CGA V-1 -1 987. 8.3 A compression-type tubing fitting shall not be used when it utilizes a slip-on ring or sleeve or a fitting requiring the use of a gasket to obtain a gas-tight joint. Exception: This requirement is not applicable when a gas-tight joint can be obtained without the use of seal material, as in the case of a gasket or an O-ring used as a secondary seal. 8.4 Pipe threads shall be in accordance with the Standard for Pipe Threads, General Purpose (Inch), ANSI/ASME B1 .20.1 -1 983(R92). 8.5 A hose connector or pigtail shall not be constructed with end fittings that would permit the connection of an appliance with a female CGA 600 connection to a LP-Gas cylinder larger than 2 1 /2 lb. (1 kg) water capacity.