Controlled closing of the valve, opens the mainline check valve, gradually increasing line pressure.
Controlled closing of the valve, opens the mainline check valve, gradually increasing line pressure.
阀门受到控制的关闭操作，开启主管线止回阀，逐渐增加管线压力。
Controlled closing of the valve, opens the mainline check valve, gradually increasing line pressure.
阀门受到控制的关闭操作，开启主管线止回阀，逐渐增加管线压力。