A valve actuator is the mechanism responsible for opening and closing a valve. Manually operated valves require a person to adjust them using a direct or geared mechanism attached to the valve stem. In contrast, power-operated systems use gas pressure, hydraulic pressure, or electricity, allowing for remote adjustment and rapid operation of larger valves. These devices can serve as the final elements in an automatic control loop, regulating flow, level, or other processes within a system.

Some actuators are designed solely to open and close the valve, while others allow for intermediate positioning for more precise flow control. Many incorporate switches or mechanisms to indicate the valve’s position remotely, enhancing operational efficiency. The choice between manual and power-operated actuators depends on the specific needs of the application and the complexity of the control systems involved. Overall, advancements in actuator technology are crucial for optimizing valve operations across various industries.