Fisher 685 actuators are large, double-acting piston actuators that provide accurate, high-thrust output for short- to long-travel applications, and are designed for use with a variety of medium to large Fisher sliding-stem control valves.
They are available for use with the FIELDVUE DVC6200 digital valve controller for throttling applications, or with switching valves for on-off control. These actuators can even be fitted with volume boosters for fast stroking requirements or a side-mounted handwheel.
Spring-return constructions have been added to the existing 685 family as the 685SE and 685SR. These constructions feature internal bias springs that force the actuator piston rod to retract (685SR) or extend (685SE) upon a loss of supply pressure, ensuring a fail open or closed mode of operation respectively.
The 685 family is available in several configurations to cover a wide range of applications. Typical travels range from 25mm to 610mm and cylinder diameters range from 305mm to 660mm. Special constructions are also available for thrusts up to 1,015kN (228,000lbf) and travels up to 1,270mm.
The 685 family effectively replaces the Fisher 585CLS actuators and buyout actuators from Automation Technology Inc. (ATI).