This part of ISO 10692 specifies a test sequence and acceptability criteria for connections between gas cylinders and valves for gases and gas mixtures used under special conditions of service where the highest levels of cleanliness and/or freedom from particles are demanded for e.g. the manufacturing of microelectronic components. It specifies a mandatory type test programme to ensure the safety of the valve to cylinder connection. Additional tests recommended for assessment of durability and other operational features of the connection are given in annex A.