This document specifies the procedures to be followed when connecting cylinder valves to gas cylinders. It specifically applies to all valve and cylinder combinations connected with ISO screw threads as specified in ISO 11363-1 and ISO 15245-1. It defines procedures and practices for inspection and preparation prior to valving for both taper and parallel screw threads. Torque values are given in Annex A for steel and aluminium alloy gas cylinders including composite cylinders with steel or aluminium alloy boss. NOTE The procedures and practices specified in this document can be beneficially applied to other valve to cylinder screw thread connection systems. ISO/TR 11364 lists the valve to gas cylinder threads in use worldwide. It gives details of the thread identification codes, whether the threads are interchangeable with ISO threads and if the taping procedure and torque values specified in this document can be used. ISO/TR 11364 gives clear guidance for the method and torque for all listed inlet threads, which are not interchangeable.