Pneumatic actuators use air power to produce rotary and linear motion. In the broadest sense, an air cylinder is a pneumatic actuator. For the purpose of this article, pneumatic actuators that are intended to produce rotary motion for operating valves, for automating manufacturing, for clamping work, etc. There are many types of pneumatic actuators available but two of the functionality actuators are most common that are Single Acting and Double Acting. The single acting actuator is also known as the spring return actuator because there is a spring and it needs only one sided compressed air supply. The compressed air pushes the actuator to either open or close.