The working principle of hydraulic pneumatic emergency cut-off valve

overview of hydraulic pneumatic emergency cut-off valve:
hydraulic pneumatic emergency cut-off valve pneumatic valve is a kind of security protection, installed in the liquid phase and gas phase of liquefied petroleum gas storage tank station on the pipeline, and hand over a long distance oil pump, hydraulic pneumatic control valve opening and closing, so that happens a lot on a pipe or tank leaking even fire, fast manual hand pump discharge pressure, or high temperature melt fusible alloy, pneumatic valve cylinder pressure relief automatically, the pneumatic valve is closed and stop leakage quickly, the safety protection.

the working principle of hydraulic pneumatic emergency cut-off valve:
more than urgent to cut off the pneumatic control valve using two hand pump, one of the oil pump work, open cut by pressurized pneumatic valve. Another pump standby, prevent damage of the first pump the pneumatic valve can not work normally, each emergency cut-off pneumatic valve before installing a needle type pneumatic valve, respectively by the needle type pneumatic valve switch to control.