The valve positioner consists of a control unit, an actuator, and a feedback sensor. The control unit processes signals from the control system and adjusts the actuator's output based on deviations between the setting signal and the feedback sensor's signal. The actuator, driven by compressed air or electric power, moves to achieve precise valve positioning. The feedback sensor monitors the valve's position and provides real-time feedback to the control unit for closed-loop control.
1.Control unit: The control unit is the core component of the valve positioner, responsible for receiving signals, processing instructions and controlling the action of the actuator. It receives the setting signal from the control system and compares it with the stem displacement signal provided by the feedback sensor, and adjusts the output signal to the actuator according to the deviation.
2.Actuator: The actuator moves according to the instruction of the control unit, and is driven by compressed air or electric power to make the valve realize precise positioning. Common actuators are pneumatic actuators and electric actuators.
3.Feedback Sensor: The feedback sensor is installed on the valve to monitor the valve position and feedback the information to the control unit. It provides a feedback signal of the actual position of the valve and realizes closed-loop control.
