EMERSON Fisher 657 and 667 Diaphragm Actuators
Rp123000.00
The Emerson Fisher 657 and 667 Diaphragm Actuators are spring-opposed pneumatic diaphragm actuators engineered for precise throttling and dependable on/off control valve operation in demanding industrial applications. These actuators are widely used in oil & gas, petrochemical, power generation, chemical processing, and general industrial process control systems.
The Fisher 657 actuator is a direct-acting design, while the Fisher 667 actuator is reverse-acting, providing flexible configuration options for various fail-safe control requirements. Designed with rugged cast iron and steel construction, both actuator series offer excellent dynamic stability, high thrust capability, and long service life under severe operating conditions.
Technical Specifications
Description | Specification |
|---|---|
Product Name | Fisher 657 and 667 Diaphragm Actuators |
Manufacturer | Emerson / Fisher™ |
Actuator Type | Pneumatic Spring-Opposed Diaphragm Actuator |
Operation | Linear Motion |
Control Function | On/Off and Modulating Control |
657 Actuator Type | Direct-Acting |
667 Actuator Type | Reverse-Acting |
Power Source | Pneumatic |
Available Sizes | 30, 40, 45, 46, 50, 60, 70, 76, 80, 87, 100 |
Signal Pressure Range | 3–15 psi, 6–30 psi (depending on configuration) |
Maximum Travel | Up to 76 mm (3 inch) |
Operating Temperature | Cryogenic to High Temperature Service |
Low Temperature Capability | Up to -50°C (-58°F) |
Construction Material | Cast Iron and Steel |
Diaphragm Material | Molded Elastomer Diaphragm |
Valve Compatibility | Globe Valves, Angle Valves |
Mounting | Yoke Mounted |
Certifications | SIL Capable, ATEX, PED, CUTR |
Accessories Available | Handwheel, Positioner, Travel Stops, Limit Switches |
Instrument Compatibility | Fisher FIELDVUE™ Digital Valve Controllers |
Application | Process Control and Shutdown Systems |
Key Features
High thrust output for precise valve positioning
Excellent linearity between loading pressure and actuator travel
Fast response and superior dynamic stability
Rugged heavy-duty construction for severe service applications
Integral mounting pad reduces external tubing requirements
Compatible with digital valve controllers and smart positioners
Optional manual handwheel and adjustable travel stop configurations
Suitable for cryogenic, low-temperature, and high-temperature applications
Easy maintenance and field-proven reliability
Typical Applications
Oil & Gas Processing
Petrochemical Plants
LNG Facilities
Refineries
Power Plants
Chemical Industries
Steam and Process Fluid Control
Emergency Shutdown Systems (ESD)
