Tag Archives: positioner

how electro pneumatic positioner works ?

  The electro -pneumatic positioner is used in Control Valves with pneumatically operated actuators. The valve is operated by means of electrical controller or Control Systems With an control signal of 4 to 20 mA or split ranges of 4~12/ 12~20 mA. Electro-Pneumatic Positioner converts this control signal into a pneumatic output in proportion to the lift of… Read More »

Working Principle of Electronic positioners

Recall that the purpose of a valve positioner is to ensure the mechanical valve’s position matches the command signal at all times. Thus, a valve positioner is actually a closed-loop control system in its own right: applying as much or as little pressure to the actuator in order to achieve the commanded valve stem position at all times.… Read More »

Working Principle of Motion-balance pneumatic positioners

Motion-balance pneumatic valve positioner designs also exist, whereby the motion of the valve stem counteracts motion (not force) from another element. The following illustration shows how a simple motion-balance positioner would work: In this mechanism, an increasing signal pressure causes the beam to advance toward the nozzle, generating increased nozzle backpressure which then causes the pneumatic amplifying relay… Read More »