Control Valves

Control valves are usually automatically operated by electric, hydraulic or pneumatic actuators. To control the opening of the valve position sensors are used, and closing of the actuator is based on pneumatic or electrical signals
Control valves are valves used to control conditions such as flow, pressure, temperature and liquid level by fully or partially opening or closing in response to signals received from controllers that compare the "nominal" to a "process variable" whose value is given by sensors that monitor changes in such conditions.