» Fisher™ · Actuators
Pneumatic Actuators
Genuine Fisher™ spring-and-diaphragm and piston actuators — 657/667, 656, 3025, 655/655R, 1052, 2052, the 585C and 685 pistons, the GX system and 644/645 pump governors — with application-engineering support and genuine OEM parts.
- Spring fail-safe action
- Sliding-stem & rotary
- Piston for high thrust
- Genuine OEM parts
What it is
The muscle behind the valve
A pneumatic actuator turns an air signal into the force and motion that strokes the valve. Spring-and-diaphragm designs are the most common in process control: air pressure works against a spring, so on loss of air the spring drives the valve to a known fail-safe position — open or closed — which is exactly why they dominate throttling service.
Piston actuators use air on both sides of a piston to deliver higher thrust and stiffness for larger valves or high-pressure-drop duties. Across both, the right actuator is the one matched to the valve, the thrust or torque required, and the fail action your process needs — and kept in service with genuine OEM parts.
The line
Fisher™ pneumatic actuators we supply
Genuine Fisher™ actuators — spring-and-diaphragm, piston, rotary and the GX system. Open each bulletin, or tell us the valve and duty and we'll confirm the right one.
Fisher™ 657 / 667
The workhorse diaphragm actuators for sliding-stem control valves — the 657 direct-acting, the 667 reverse-acting (spring fail-safe). Integral mounting pad and air passage.
Fisher™ 656
Long-stroke, direct-acting diaphragm actuator for bracket-mounted service — Vee-Ball and butterfly valves, louvers and dampers.
Fisher™ 3025
Long-stroke spring-opposed diaphragm actuator delivering small-to-medium thrust for sliding-stem valves, with strokes up to 200 mm.
Fisher™ 655 / 655R
Diaphragm actuators for self-operated control: the 655 for pressure reduction (push-down-to-close), the 655R for pressure relief (push-down-to-open).
Fisher™ 585C
Double-acting piston actuator delivering low-to-medium thrust for small-to-medium sliding-stem valves where higher thrust or stiffness is needed.
Fisher™ 685
Double-acting piston actuators for medium-to-high thrust on medium-to-very-large sliding-stem valves (easy-e™, HP, EH, FB, 461) — thrust up to 354 kN.
Fisher™ 1052
Spring-return diaphragm rotary actuator for splined-shaft rotary valves — on/off or throttling service.
Fisher™ 2052
Compact spring-and-diaphragm rotary actuator for throttling or on/off control in space-constrained installations.
Fisher™ GX
An integrated control-valve and actuator system with automatic actuator selection and replaceable trim — compact, across a wide range of flow and line sizes.
Fisher™ 644 / 645
Direct-operated pump-governor actuators that automatically control steam-driven boiler feedwater pumps when paired with sliding-stem valves.
Spring-and-diaphragm
Fail-safe by design
Air works against a spring, so loss of air drives the valve to its safe position — open or closed. The most common choice for throttling control: simple, reliable, and the natural pairing for sliding-stem and rotary valves (657/667, 656, 3025, 655, 1052, 2052).
Piston
High thrust & stiffness
Air on both sides of a piston delivers higher thrust and stiffness for larger valves and high-pressure-drop service (585C, 685). Fail-safe is added with accessories where the process requires it.
Genuine OEM
Genuine Fisher™ actuator spare parts
Most actuator problems are solved with the right genuine part, not a whole new actuator. We supply OEM diaphragms, springs, seals, O-rings, stem connectors and repair kits to keep 657/667, 656, 3025, 655, 585C, 685, 1052, 2052 and GX assemblies stroking accurately and failing safe.
Tell us the valve, the thrust or torque and the fail action — our team will confirm the right Fisher™ actuator or genuine parts.
Resources & tools
Spec it, look it up
Each model above links to its Fisher™ bulletin. Here's the rest of what you need to select and support an actuator.
Technical library
Handbooks & application guides
The Fisher™ reference material behind every actuator selection.
Browse the library →Free tool
Fisher™ Obsolete & Inactive Lookup
Running a discontinued Fisher™ actuator? Find its recommended replacement.
Look it up →Electric option
easy-Drive™ electric actuators
No instrument air on site? See the 200L and 200R electric actuators.
View electric →Downloads
Datasheets & brochures
Bulletins and brochures across Fisher™ and the full line.
Browse downloads →Need a Fisher™ actuator or parts?
Tell us the valve and the duty — genuine OEM, shipped from our Orlando, FL warehouse.