ISO 4126-4:2013规定了先导式安全阀的一般要求，无论其设计用于何种流体。在所有情况下，操作都是由待保护系统中的流体执行的。 它适用于阀门流量直径为4mm及以上的先导式安全阀，用于0.1bar及以上的设定压力。温度没有限制。 ISO 4126-4:2013是一项产品标准，不适用于先导式安全阀的应用。

ISO 4126-4:2013 specifies general requirements for pilot operated safety valves, irrespective of the fluid for which they are designed. In all cases, the operation is carried out by the fluid in the system to be protected. It is applicable to pilot operated safety valves having a valve flow diameter of 4 mm and above which are for use at set pressures of 0,1 bar gauge and above. No limitation is placed on temperature. ISO 4126-4:2013 is a product standard and it is not applicable to applications of pilot operated safety valves.