Tuesday, September 3, 2013

Defining a "Quick Acting" Pneumatic Actuator

ROTEX Fast acting actuator
The desired speed of the pneumatic actuator opening or closing is a consideration of the application itself. For applications where an open valve may feed a fire, or overfill a tank, quick closing is required. Conversely, there are times when lines or tanks need to vented very quickly, or processes must be diverted quickly, and a fast opening actuator is applied.

Pneumatic Actuators can vary in opening and closing speed, depending on air supply, venting orifice, and/or size spring involved. A very general statement of valve actuator opening/closing times is normally in the "tens of seconds" whereas fast acting actuators open or close typically in less than 5 seconds.

The engineering of quick acting actuators must be done by seasoned professionals who fully understand the process. Other considerations when applying fast acting actuators are redundancy, failure mode (loss of energy supply), media, criticality and size.

Picture courtesy of Rencor Controls.