Actuator Description

The RPS actuator features a pneumatic low pressure spring return and is suitable for any angular stroke rotary application such as shutting off and regulating ball, plug, butterfly or vibration dampened valves in heavy duty service. 

The actuator consists of a rack and pinion mechanism that drives the linear motion of the pneumatic cylinder in one direction and converts the linear motion of the spring into rotary motion for valve operation in the opposite direction. An adjustable bronze slide supports the lateral force applied to the rack by engaging with the pinion gear. The rack is nitrided to ensure minimum friction. 

The spring module contains one spring or www.cniacs.com two springs in series depending on the model and is fully encapsulated, which ensures personnel safety and easy assembly. External travel limit bolts allow precise angular travel adjustment between 80° and 100°.

The fully enclosed protective housing is made of ductile iron for maximum strength and is suitable for use in harsh environments.

The mounting flanges are identical on both (top and bottom) sides of the housing; the shaft output actuators have the same dimensions but are positioned at 90°. This allows the actuator to be used as a closing or opening spring without modification.

The actuator is assembled to the valve by connecting the actuator housing flange to the valve flange with a sleeve and, using the stem extension shaft, connecting the actuator shaft bore to the stem.

Rotate the jacking bolt with a hand lever or handwheel (available on request) to perform a manual emergency operation of the actuator in opposition to the spring action. 

The mounting flange on the top of the housing can be used to assemble limit switches, position sensors, positioners, etc. driven by the actuator output shaft.