Fail-Safe Operation
For applications, where fail-safe operation is a requirement, PowerRac
Rack & Pinion Design
® ® The PowerRac actuator features a rugged
rack and pinion design with hardened steel gears. Nominal play in the gears combined with a
rigid coupling between the valve shaft and positioner drive allows thrust from the cylinder to precisely position the valve on modulating service.
3 actuators are available with a spring return option. The spring is caged at the factory for increased safety. Double acting actuators can be converted to spring return action by adding a spring cartridge. Unlike other actuators, adding a spring cartridge to a PowerRac
® does not reduce the operating torque. For added versatility, action can be changed from fail open to fail closed.
Piped accessories come standard with rubber
industrial hoses and
brass fittings. They are also available with 316 stainless steel fittings and tubing.
Valve Coupling
A unique internal square collet* clamps the drive pinion to the valve shaft with a single external screw, totally eliminating all backlash in the drive connection. Direct actuator to valve mounting makes the valve/actuator package as compact as physically possible.
Direct Mounted Positioner
Positioners are solidly mounted on the actuator housing with a rigid coupler, feeding exact valve position directly to the positioner. No lost motion assures accurate valve positioning.
Positioner options include both pneumatic and electronic signal range, as well as U.L., C.S.A. and European electrical approval ratings. Span and zero adjustments can quickly be made, simplifying calibration and maintenance.
*Patent number 5,176,464 3