A Positioner is a device used to increase or decrease the air load pressure driving the actuator to place the controlled equipment to a specific position. This is performed by means of a input and output signal, that can be either pneumatic or electrical,
The operation of a control valve involves positioning its movable part (the plug, ball or vane) relative to the stationary seat of the valve. The purpose of the valve actuator is to accurately locate the valve plug in a position dictated by the control signal.
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