减压阀是基于压力开关的控制元件。根据 EN 50156-1 标准，一旦达到定义的极限值，它就会中断过程，直到手动复位为止。该标准强制要求高压釜、冷却器和某些化学反应器等应用必须使用泄压阀。

　　原文：

　　A pressure relief valve is a control component based on a pressure switch. According to the EN 50156-1 standard, it interrupts the process as soon as a defined limit value is reached until it is manually reset. This standard makes pressure relief valves mandatory for autoclaves, chillers, and certain chemical reactors, among other applications.