Pneumatic emergency shut-off valve

, QDQ421F-40 pneumatic emergency shut-off valve in the absence of pressure, the valve is normally closed state, when the pressure of the gas input of the pump cylinder valve, the valve is turned on, or when you need to close the valve in case of emergency, the pressure vent shut off automatically. Second, the valve is fixed to the seat by the plunger, ie when the cylinder valve, when the pressure of gas injected into the cylinder through the valve seat, the valve that is away from the seat when the pressure vent out, the spring force of the valve due, quickly closed. Third, the flow direction of the working medium valve seat for the outlet end, no seat side is the importer and gas pressure in the opposite direction.