Actuators & Accessories
Actuators and accessories are the core of valve automation and remote control. An actuator converts air, electric or hydraulic power into torque or thrust to drive ball, butterfly, gate and other valves for on/off or modulating duty; accessories (valve positioner, limit switch, solenoid valve, filter regulator) add precise control, position feedback and safety interlock functions. By power source there are pneumatic (rack-and-pinion, diaphragm, piston), electric (multi-turn or quarter-turn, IP66–IP68, optional Exd IIB/IIC T4 explosion protection) and hydraulic types. Pneumatic actuators are double-acting or single-acting with spring return (fail-closed / fail-open); emergency shutdown valves for safety instrumented systems (SIS) must meet SIL (IEC 61508/61511). Mounting interfaces conform to ISO 5211/5210. A valve positioner takes a 4–20 mA signal and closes the position loop, improving control accuracy. Solenoid emergency shutdown valves can be interlocked with combustible gas alarms, fire alarms and DCS/ESD systems for rapid isolation in an emergency. For hazardous areas, actuators and accessories can be supplied in ATEX-certified versions.
Solenoid Emergency Shut-Off Valve
The Solenoid Emergency Shut-Off Valve consists of a valve body and a solenoid drive mechanism. Energizing or de-energizing the solenoid drives the valve to close quickly, providing emergency shutdown (ESD) protection for gas lines, oil and gas pipelines and industrial plants. It features fast closing and automatic or manual reset, and can be interlocked with combustible gas detectors, fire alarms or DCS/ESD systems to shut off automatically under leakage or accident conditions. A manual reset mechanism is available to meet the reliability requirements of safety instrumented systems.
Valve Positioner
The Valve Positioner receives a signal from the control system and performs closed-loop correction based on valve position feedback, outputting a pneumatic signal to drive the actuator so that the valve position follows the setpoint precisely and quickly. It is a key accessory for control valve accuracy. The electro-pneumatic positioner accepts a 4–20 mA signal and uses a cam or feedback lever for precise stroke control, with zero and span adjustment, split-range control and characteristic correction. The smart version supports HART communication and self-diagnostics.
Electric Actuator
The Electric Actuator uses a motor-driven gear reduction to deliver output torque or thrust, operating multi-turn or quarter-turn valves on/off or modulating. It requires no air supply, is simple to wire and supports remote control. An integrated control unit supports on-off, modulating and bus types (Modbus/Profibus/HART). Enclosure protection can reach IP67/IP68, with optional explosion-proof Exd IIB/IIC T4. It suits applications without an air supply or requiring precise modulation.
Pneumatic Rack-and-Pinion Actuator
The Pneumatic Rack-and-Pinion Actuator converts the linear motion of the piston into rotary motion through a rack on the piston meshing with a pinion on the output shaft, delivering output torque to drive 90° rotary valves such as ball valves and butterfly valves. Two versions are available: double acting and single acting spring return. Double acting is switched by supplying air in either direction; single acting returns to the safe position (FC or FO) by spring on loss of air supply. The cylinder is anodized or painted for corrosion protection, and the top mounting platform conforms to ISO 5211, allowing solenoid valves, positioners and limit switches to be fitted.