Valve Actuators & Automation

Actuator Types

Electric Actuators

Electric actuators use an electric motor to operate the valve. They are the most versatile type — suitable for modulating control, on/off operation, and monitoring with full feedback and diagnostics.

• Multi-turn electric actuators: For gate valves, globe valves, and multi-turn valves. Torque range from 30 Nm to 3000+ Nm. Key brands: Rotork IQ3, AUMA SA/SAR, Limitorque MX/L120.
• Quarter-turn electric actuators: For ball valves, butterfly valves, and plug valves. Torque range 40–4000 Nm. Key brands: Rotork IQT, AUMA SQ, Limitorque QX, EIM TEC2000.
• Linear electric actuators: For control valve positioners and linear-motion valves.

Pneumatic Actuators

Pneumatic actuators use compressed air to operate the valve. They are fast, simple, and intrinsically safe for hazardous areas (no electrical components in the actuator). Common in oil & gas, petrochemical, and ATEX environments.

• Scotch-yoke actuators: High torque output at end positions. Used for quarter-turn valves in oil & gas. Key brands: Bettis (Emerson), Rotork Skilmatic.
• Rack-and-pinion actuators: Compact, moderate torque. Used for small to medium quarter-turn valves. Key brands: OMAL, Valbia, Rotork CP range.
• Spring-return actuators: Fail-safe operation — valve returns to safe position (open or closed) on air/power failure.
• Double-acting actuators: Air used for both open and close strokes — requires reliable air supply for fail-safe operation.

Hydraulic Actuators

Hydraulic actuators use hydraulic fluid (oil) for very high torque output. Used for large-diameter pipeline valves, subsea valves, and applications requiring high force in compact sizes. Key brands: Rotork Hydraulic, Cameron HC.

Electro-Hydraulic Actuators (EHA)

Self-contained electric-motor-driven hydraulic units — no external hydraulic power unit required. Rotork Skilmatic and Tri-Torq are common EHA brands.

Accessories & Controls

• Solenoid valve assemblies: For pneumatic actuator control.
• Limit switches and position sensors: For open/close feedback and modulating position indication.
• Smart positioners: For modulating control of pneumatic actuators (Rotork Fairchild, YTC, Fisher DVC6200).
• Partial stroke testing (PST) devices: For safety valve testing without full closure (Topworx, Rotork).
• Handwheels and manual overrides: For manual operation during power failure.
• Gearboxes: Reduce actuator torque requirements for large valves (Rotork Gears, Limitorque gearboxes).