Initial movement of the valve stem in the opening direction unseats the pilot valve.

当阀杆向开启方向移动，首先使先导阀脱离阀座。

The flushing action is achieved as the compressed purge media is released to become the flush media when the plug unseats .

当阀塞离开阀座位置时，被压缩的清洗流体介质变成冲刷流体介质，实现冲刷作用。