Parameter Specification / Description Model Series Fisher 655 Actuator Type Scotch-Yoke / Rack and Pinion Pneumatic Piston Actuator Configurations Double-Acting (Air-to-Air): Requires air to open and close. No fail-safe spring. Spring-Return: Provides fail-safe action (fail-open or fail-closed) upon air supply loss. Actuator Sizes 30, 40, 50, 60, 70, 80 (The number indicates the piston diameter in millimeters) Standard Supply Pressure 40 to 120 psi (2.8 to 8.3 bar) Temperature Range Standard: -4° to 180°F (-20° to 82°C) Low Temp.: -40°F (-40°C) with optional seals & lubrication Mounting Directly to ISO 5211 mounting pads and NAMUR (VDI/VDE 3845) compliant valves. Accessory Mounting NAMUR standard for easy attachment of solenoid valves, limit switches, and positioners. Body Material Standard: Aluminum with corrosion-resistant epoxy coating. Optional: Stainless Steel (e.g., for corrosive environments). Spring Material Carbon Steel Piston Seals Standard: Buna-N Optional: Ethylene Propylene (EPDM), Fluorocarbon (Viton)
