Pneumatic actuators: single acting vs double acting

DIFFERENCES BETWEEN SINGLE AND DOUBLE ACTING

A pneumatic actuator is a device that transforms the energy of compressed air into mechanical energy, this characteristic allows it to open or close valves control in piping systems.

In industrial applications of isolation or throttling valves, there are two different designs of actuator, if we understand the nature of its operation we will be able to determine which will be the best option for our installation:

In the case of the single acting actuator, it is characterized by being actuated by air on one side while on the other side it moves with help of a spring or membrane. Therefore, only one side of the actuator needs to be pressurized.

The double-acting actuator only uses one piston as an element to operate the valve, therefore, the actuator must be pressurized alternately from both sides.

Next, you can see the differences between both actuators in the following drawing:

WHICH IS THE BEST OPTION?

Depending on its design, a single or double acting actuator may be more optimal with respect to the requirements of the application, let’s see several cases: