scope:

This part of ISO 23551 specifies safety, constructional and performance requirements and testing of automatic valves (hereafter referred to as valves) for gas burners, gas appliances and similar use. This part of ISO 23551 covers type testing only. This part of ISO 23551 applies to valves with declared maximum working pressures up to and including 500 kPa, for use on burners or in appliances using fuel gases as natural gas, manufactured gas or liquefied petroleum gas (LPG). This part of ISO 23551 applies to valves directly or indirectly operated electrically or by mechanical means. This part of ISO 23551 applies to valves actuated by fluids e.g. pneumatic, hydraulic. This part of ISO 23551 applies to valves where the flow rate is controlled by external electrical signals, either in discrete steps or proportional to the applied signal. This part of ISO 23551 applies to valves fitted with closed position indicator switches.