The CVS Series 1051/1052 Diaphragm Rotary Actuator is a pneumatic spring-return actuator designed for use with rotary-shaft control valves. This is a direct-acting actuator, and an increase in the loading pressure extends the diaphragm rod out of the spring barrel. The CVS Type 1051/1052 Actuator is suitable for on-off service, or for throttling service when used with a valve positioner. The Series 1052 Actuator includes a spring adjuster, which is suitable for use with or without a positioner.