This SAE Recommended Practice defines minimum functional requirements for quick connectors used in supply and return, liquid lines, for flexible tubing fuel systems. The document applies to automotive and light truck gasoline and diesel fuel systems, with operating pressures up to 500 kPa, 5 Bar, (72.5 psig), and the fuel lines and connectors routed such that continuous operating temperature exposure is less than 115 °C (239 °F). These tests apply to new fittings in assembly operations: for service operations, the male tube should be lubricated with engine oil before coupling. Vehicle O.E.M. fuel system specifications may impose additional requirements beyond the scope of this general SAE document. In those cases, the O.E.M. specification takes precedence over this document.