The D-3240 Series pneumatic piston actuators are multipurpose positioning devices designed for operating inlet vanes on centrifugal fans and compressors in direct response to the output signal of a pneumatic controller. These actuators can also be used on other applications that require a large amount of positioning power from a single actuator, such as large damper applications, provided that the damper is designed to withstand the high torque capabilities of the actuator.