Page 320 - CITS - Electronic Mechanic - TT - 2024

ELECTRONICS MECHANIC - CITS

Pneumatic piston actuator
A pneumatic actuator is a device that converts the energy of compressed air into motion according to an applied
control signal. When using a diaphragm actuator, there is a shorter stroke length and smaller thrust range due to
the diaphragm. To achieve a larger stroke length and higher thrust, we use a sealed

piston enclosed in a metal cylinder. Here the desired stroke length can be obtained by changing the length of
the cylinder and the desired thrust can be obtained by changing the internal diameter of the cylinder. The piston
actuator can be either signal acting type with one signal port with a spring return mechanism or double acting type
with two air ports available. Piston cylinders are used for large stroke applications (such as damper actuator). The
diagram of 2 different configurations of piston actuator is shown below-
Piston Actuator
A diagram showing various parts and components is shown below-

Parts of a piston actuator

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CITS : E & H - Electronics Mechanic - Lesson 188 - 198