This Standard specifies outlet connection dimensions for a system of diameter-indexed valve connections for a limited range of nominated gases.NOTE: Requirements for other aspects of the valves are specified by reference to AS 2473. Requirements for valves employing the pin-indexed outlet connections (for medical application) are specified in AS 2472.This Standard does not apply to valves for portable gas cylinders of less than 11 kg water capacity for self-contained breathing apparatus, or to valves for fire extinguishers.