Basic actuators are used to drive valves to the fully open or fully closed position. Actuators used for valve control can precisely move valves to any position. Although most actuators are used for opening and closing valves, modern actuator designs go far beyond simple on/off functions. They incorporate position sensors, torque sensors, electrode protection devices, logic control devices, digital communication modules, and PID control modules, all housed in a compact housing.
As more and more factories adopt automated control, replacing manual operation with mechanical or automated equipment, there is a growing demand for actuators to act as the interface between the control system and the mechanical movement of the valve. Furthermore, actuators must enhance operational safety and environmental protection performance. In hazardous situations, automated actuators can reduce personnel injury.
Some special valves require emergency opening or closing under special circumstances. Valve actuators can prevent further spread of danger while minimizing plant damage. For some high-pressure, large-diameter valves, the required actuator output torque is very large. In such cases, the actuator must have improved mechanical efficiency and use a high-output motor to ensure smooth operation of large-diameter valves. For valves with low torque, miniature electric valves have also been developed, which have advantages such as light weight, compact structure and full functionality compared to ordinary types.
