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.
