The air operated plunger-type trip valve (i.e. plunger type trip valve), is in the air operated unit combination measuring appliance's execution unit. It receives from regulation meter's signal, in the control process tube the fluid cut-off and the connection or cuts the flow channel. This product has the operation strength to be big, the valve chest modern design, the resistance to flow small, the rated flow coefficient big, permits with the differential pressure is big, sealing property fine and so on merits. Therefore widely applies in Industry sector's and so on petroleum, chemical industry, metallurgy, electric power, light industry production process automatic control and in the remote control system.

The air operated plunger-type trip valve is composed of the air operated plunger type implementing agency and the straight traveling schedule control element two parts, middle becomes by the support connection. According to control element's pattern, the air operated plunger-type trip valve may divide into goes nonstop to the single-seat trip valve (ZSQP), the nonstop sleeve trip valve (ZSQM), two Three Contacts trip valves (ZSQN) three patterns. The air operated plunger type implementing agency has the list to affect (spring replacement) and the double-acting (double air admission) two kinds. Uses the list function implementing agency, the complete machine function way may divide into the gas valve type (horizontal pipeline connection) to open the type friendly (horizontal pipeline separation). The air operated plunger-type trip valve has the hard seal and seals two kind of seal forms softly, is suitable separately for the different temperature and the pressure.
    When the signal pressure is zero, because the spring (list function only has) the pretightening up force, causes the valve core to be at the original state (Chang Kaihuo often to shut). When the implementing agency receives the signal pressure (0.4~0.6MPa), on the piston has the thrust force, the compression spring, drives the throwout lever, the valve chest, the valve core to move to the limiting position, causes the valve to open or the entire pass. Achieves to the pipeline between the medium connection, the cut-off or the pipeline the hand-off control. Uses for parts two Three Contacts solenoid valves, causes the plunger-type trip valve control to be more convenient simple and direct.