| 1 | Electric Quarter-Turn Actuator | Electric motor with gear reduction | Ball, butterfly, plug and small rotary-control valves | Typically 50–4,000 N·m; confirm the valve breakaway and running torque | On/off or modulating service; commonly paired with limit switches, position feedback and digital controls | Usually not inherent; requires a spring-return module, battery backup or a separate emergency system | Water treatment, HVAC, compressed air, utility piping and general process isolation | Best for clean, accessible power
Check torque margin, duty cycle, supply voltage, ambient temperature and control signal | Align the actuator and valve stem, use the correct mounting interface, set travel limits and verify rotation direction before coupling | Inspect electrical terminals, seals and limit settings; check gearbox lubrication and perform functional cycling according to the duty cycle |
| 2 | Double-Acting Pneumatic Quarter-Turn Actuator | Compressed air applied alternately to both sides of a piston or vane | Ball, butterfly and plug valves | Approximately 10–100,000 N·m, depending on air pressure and actuator size | Excellent for fast on/off operation; modulating control requires a positioner and suitable control accessories | Requires an external spring-return or air-reservoir arrangement for fail action | Oil and gas, chemical processing, water treatment, bulk handling and hazardous-area installations | Best for fast, repetitive cycling
Verify air pressure, air quality, required speed, torque at end positions and area classification | Install a correctly sized air set, filter-regulator, solenoid valve and tubing; ensure clean, dry instrument air and proper valve alignment | Check air leaks, tubing, fittings, solenoid operation, mounting bolts and cycle time; inspect the drive mechanism at scheduled intervals |
| 3 | Spring-Return Pneumatic Actuator | Compressed air in one direction with mechanical springs for the return stroke | Ball, butterfly, plug and emergency-shutdown valves | Approximately 10–50,000 N·m; spring torque varies during the stroke | Primarily on/off; modulating operation is possible with an appropriate positioner and control package | Built-in fail-open or fail-closed action | Fuel gas isolation, burner management, chemical safety systems, process shutdown and fire-protection services | Best when a defined safe position is essential
Match spring torque to valve torque throughout the full stroke and account for supply-pressure loss | Confirm the required fail direction, install the solenoid and exhaust components correctly, and test the fail stroke after commissioning | Test emergency closure or opening regularly; inspect springs, seals, air leaks, position feedback and corrosion around the actuator housing |
| 4 | Electric Linear Actuator | Electric motor driving a screw, lead screw or ball screw | Globe, diaphragm, pinch and linear control valves | Typically 1–100 kN thrust with strokes commonly from 25–300 mm | Well suited to precise modulating control using analog, fieldbus or digital command signals | May use a brake, mechanical spring, battery backup or a separate fail-safe assembly | Steam control, water regulation, district energy, heating systems and process-flow control | Best for accurate linear positioning
Check thrust, stroke, seating force, control resolution, duty cycle and valve differential pressure | Keep the actuator and valve stem coaxial, prevent side loading, set the stroke limits and verify the seating force without over-compressing the valve | Inspect stem alignment, screw or gear lubrication, backlash, limit switches and position calibration; keep the enclosure sealed |
| 5 | Electro-Hydraulic Actuator | Electric motor-driven hydraulic pump and cylinder or rotary hydraulic motor | Large ball, butterfly, plug and high-force linear valves | Rotary output commonly 5,000–1,000,000 N·m; linear force may exceed 100 kN | On/off or high-accuracy modulating control; suitable for slow, controlled movement under heavy loads | Can incorporate accumulators, spring mechanisms or hydraulic fail-safe circuits | Pipeline transmission, hydroelectric facilities, heavy process equipment and remote valve stations | Best for high force with limited utility infrastructure
Evaluate hydraulic response time, reservoir capacity, ambient temperature and emergency operating requirements | Use clean hydraulic fluid, correctly rated hoses and fittings, adequate structural supports and carefully vented hydraulic circuits | Check fluid level and contamination, inspect hoses and seals, test accumulator pressure, monitor leakage and verify emergency operation |
| 6 | Hydraulic Quarter-Turn Actuator | Pressurized hydraulic fluid driving a rotary vane or piston mechanism | Large ball, butterfly and plug valves | Approximately 5,000–1,000,000 N·m, depending on hydraulic pressure and actuator size | High torque and controlled speed; modulation requires proportional hydraulic control and position feedback | Possible through spring-return designs, hydraulic accumulators or independent shutdown circuits | Offshore platforms, pipeline systems, power generation, marine systems and large water infrastructure | Best for very high torque in compact equipment
Confirm hydraulic pressure, torque at the full stroke, fluid compatibility and environmental protection | Flush hydraulic lines before connection, prevent contamination, support heavy components and verify the valve’s mechanical stops | Inspect for leaks, hose degradation, corrosion and contamination; check pressure, seals, mounting hardware and full-stroke operation |
| 7 | Direct-Drive Electric Actuator | Low-speed high-torque electric motor with minimal or no external gearbox | Quarter-turn and selected multi-turn valves requiring low-speed positioning | Typically 100–10,000 N·m, subject to motor design and duty rating | Precise positioning with reduced mechanical backlash; supports on/off and modulating control | Usually requires a separate battery, spring or mechanical emergency arrangement | Precision water control, process skids, laboratory utilities and applications where low backlash is important | Best for positioning accuracy and low backlash
Assess starting torque, thermal limits, holding torque, speed, power quality and manual override needs | Mount without shaft stress, establish accurate end positions and provide adequate electrical protection and heat dissipation | Check position accuracy, motor temperature, cable glands, bearings and end stops; inspect for moisture ingress and abnormal noise |
| 8 | Multi-Turn Electric Actuator | Electric motor and gearbox producing several shaft rotations | Gate, globe, sluice and rising-stem valves | Typically 50–4,000 N·m at the output, with thrust capability determined by the attached thrust unit | On/off or modulating control; suitable for valves requiring multiple turns and position feedback | May require a battery, spring mechanism or external shutdown system | Power plants, water distribution, wastewater treatment and large utility networks | Best for rising-stem and multi-turn valves
Separate and verify torque and thrust requirements; check stem travel, seating load and valve operating time | Use the correct thrust base, keep the stem clean and aligned, set open and closed limits, and prevent excessive seating torque | Inspect thrust bearings, stem lubrication, limit switches, torque switches and gearbox oil; test local and remote controls |
| 9 | Solenoid-Operated Valve Actuator | Electromagnetic coil moving a plunger or pilot spool | Small process valves, pilot valves and compact on/off valves | Typically handles small valve sizes; output is generally suitable for low-flow isolation or pilot control | Very fast on/off operation; not normally intended for continuous throttling | Normally closed or normally open configurations provide a defined position when de-energized | Instrument air, water dosing, fuel trains, pneumatic pilots and compact automation panels | Best for fast compact switching
Check coil voltage, pressure differential, flow direction, response time, seal material and electrical classification | Install a clean upstream filter when required, observe flow direction, protect wiring from heat and confirm correct coil voltage | Check coil heating, electrical connections, plunger movement, filter cleanliness, leakage and response time |
| 10 | Manual Gear-Assisted Actuator | Handwheel, chainwheel or gearbox multiplying human input | Large gate, globe, butterfly, ball and plug valves where powered actuation is unnecessary | Commonly suitable for manual operating torques from approximately 100–10,000 N·m | Manual on/off positioning; limited throttling unless the valve is specifically designed for it | Safe position depends on the operator; no automatic fail-safe action | Remote water lines, low-cycle utility isolation, maintenance bypasses and locations without reliable power | Best for simple, low-cycle isolation
Evaluate operator access, required handwheel effort, valve cycle frequency, space and lockout requirements | Mount securely, maintain correct stem engagement, provide safe access and install position indicators and locking devices where needed | Lubricate gears and valve stems, inspect handwheels and guards, check fasteners and verify that the valve can complete a full stroke |
