ZSQ light pneumatic piston cut-off valve is the execution unit in the pneumatic unit combination instrument. It receives signals from the regulator and controls the cut-off and switching-on or switching-off of the flow channel in the process pipeline.

Principle of action

  When the signal pressure is zero, the valve core is in the initial state (usually open or closed) because of the pre-tightening force of the spring (single action only). When the actuator receives the signal pressure (0.4-0.6 MPa), the compression spring drives the push rod, the valve body and the valve core to move to the limit position to make the valve fully open or closed. To achieve the medium in the pipeline to connect, cut off or switch between pipelines control. The use of two-position three-way electric sample valve makes the control of piston cut-off valve more convenient and simple.

Structural Principle

  Pneumatic piston cut-off valve is composed of two parts: pneumatic piston actuator and straight stroke regulating mechanism. The middle part is formed by the side of bracket. According to the form of regulating mechanism, pneumatic piston cut-off valve can be divided into three types: through single-seat cut-off valve (ZSQP type), through sleeve cut-off valve (ZSQM type) and two-position three-way cut-off valve (ZSQN type). Pneumatic piston actuator has two kinds: single action (spring reset) and double action (double intake). Using single-acting actuator, the whole machine can be divided into air-closed (horizontal pipeline connected) and air-opened (horizontal pipeline disconnected). Pneumatic piston cut-off valve has two sealing forms: hard seal and soft seal, which are suitable for different temperature and pressure. ZSQM pneumatic piston sleeve cut-off valve adopts balanced spool, which can increase the cut-off pressure difference. Two-position three-way cut-off valve adopts four-way valve body with three channel ports, which is especially suitable for switching between two flow paths. 
Major Parts Materials