Working principle of pneumatic butterfly valve Pneumatic butterfly valve is a kind of valve whose valve plate rotates around a fixed axis perpendicular to the channel. It is composed of a piston type double action or single action (spring return type) pneumatic actuator and butterfly valve. It is a rotary high-performance regulating or shut-off valve. Its principle is as follows:

The electro pneumatic valve positioner, powered by electric signal and compressed air, receives 0-10mA? Input from the control system? DC or 4-20mA? The DC current signal is converted from compressed air to air source pressure signal input and output by the regulator to change the rotation angle of the valve plate (0-90o any angle), which has better parameters such as flow regulation and control.