Pneumatic Diaphragm Actuator Control Valve

The compressed air is applied to a solid piston contained within a solid cylinder.

Pneumatic diaphragm actuator control valve.

A area of the diaphragm p air pressure k spring. 1 5 1 basics of actuator sizing in a spring diaphragm actuator any valve position is achieved by making the total force on the stem equal to zero. A pneumatic actuator mainly consists of a piston or a diaphragm which develops the motive power. Find out about the differences between electric and pneumatic actuators the relationship between direct acting and reverse acting terminology and how this affects a valve s controlling influence.

This actuator is a linear motion device ideal for valve sizes ranging from the micro flow valves to large 20 globe control valves. Valve housing and diaphragm available in various materials and designs surfaces in contact with the product from ra 0 38 µm 1 6 µm optionally electropolished available in all common connection sizes and variants. Piston actuators are generally used where the stroke of a diaphragm actuator would be too short or the thrust is too small. The importance of positioners is discussed with regard to what they do and why they are required for many applications.

Piston actuators can be single acting or double acting can withstand higher input pressures and can offer smaller cylinder volumes which can act at high speed. It keeps the air in the upper portion of the cylinder allowing air pressure to force the diaphragm or piston to move the valve stem or rotate the valve control element. Swapan basu ajay kumar debnath in power plant instrumentation and control handbook 2015.