A pneumatic actuator control is a system in which air pressure is transferred into linear or rotary motion. These actuator controls work automatically in many cases and are often designed to maintain a certain pressure within a system. Several applications for these controls are generally related to storage or low-power tooling. Advantages to these types of actuators stem from the relatively low cost and ease of use. Disadvantages typically arise from the physical limitations of a pneumatic actuator system.
Compressed air pressure is converted into motion within a pneumatic actuator control. As pressure is released into the actuator cylinder, a piston is typically forced into a certain position. This motion typically closes off a valve, sealing it while the pressure remains at a certain threshold. If that air pressure changes, the pneumatic actuator control also changes position and may release air or close even tighter. In cases in which the actuator is controlling an intake valve, for instance, lower air pressure would relax the valve, allowing more air to flow past the seal and build up new pressure to close it.
Applications for a pneumatic actuator control system are often related to air systems. Storage facilities might use these types of actuators to control the flow of air between storage facilities and distribution points. Compressed air tanks might use a pneumatic actuator control to detect when more air must be pumped in to achieve a certain pressure. Tasks that have a constant output and variable input also can benefit from the use of a pneumatic actuator control to maintain constant pressure.
Advantages to these types of actuators make them useful in many of these applications. A pneumatic actuator control is generally cheaper to install and maintain than some other methods. Despite this low cost, they also are considered reliable even over a long life and can maintain constant pressures better than many other controls. A pneumatic actuator control also can increase the input force substantially, sometimes even increasing the given force by two or three times.
Disadvantages to these systems can include performance variations when constant shifting of air pressure is required. In these cases, incorrect pressures activating an actuator can lead to leaking and general inefficiency. A pneumatic actuator control also is fairly limited in the forces it can handle. There is often an upper threshold of pressure that can be maintained and transferred into motion before the stress becomes too much or too little.
