These requirements cover hose and hose assemblies in sizes up to and including a nominal internal diameter of 4 in (102 mm) for conveying liquefied petroleum gas (LP-Gas) intended to be installed in closed systems in compliance with the Standard of the National Fire Protection Association Liquefied Petroleum Gas Code@ NFPA 58. The hose or hose assembly is intended for a maximum working pressure of 350 pounds per square inch gauge (psig) (2400 kPa) for use at temperatures within the range of minus 40??(minus 40?? to plus 60??(140??@ or minus 54??(minus 65?? to plus 60?? Hose and hose assemblies in sizes larger than 2 in (50.8 mm) are not intended for use on reels. This standard does not apply to: a) Flexible hose connectors for LP-Gas that are investigated under the Standard for Pigtails and Flexible Hose Connectors for LP-Gas@ UL 569; b) Gas appliance connectors for handling fuel gases at 5 psig (34.5 kPa) or less@ which are investigated under Connectors for Gas Appliances@ ANSI Z21.24@ nor to metallic hose intended for use in oil transportation piping@ in petroleum refinery piping@ or in gas transmission and distribution piping systems; or c) Hose intended for use in automotive applications or hose intended for use in confined areas. d) Hose assemblies that are investigated under Gas Hose Connectors for Portable Outdoor Gas-Fired Appliances@ ANSI Z21.54.
UL 21-2014 history
2017UL 21 BULLETIN-2017 UL Standard for Safety LP-Gas Hose (COMMENTS DUE: June 19@ 2017)