Pipe Unions for Flammable and Combustible Fluids and Fire-Protection Service
UL 860
1 Scope
1.1 These requirements cover pipe unions to be employed in piping carrying designated flammable or combustible fluids or in piping connections to equipment supplying water for fire-protection service.
1.2 “Flammable and Combustible Fluids,” as used herein, means gases and liquids that are investigated and found to be flammable or combustible, such as acetylene, fuel oil, gasoline, kerosene, liquefied petroleum gas, and manufactured and natural fuel gases.