Pneumatic butterfly valve D671X 1. Pneumatic butterfly valve operating torque is the torque rotating the valve operating torque one of the smallest of all valves open and close rapidly, compressed air-powered piston rack gear mechanical transmission stem to the rotary output board 0 ~ 90 º, will be able to quickly complete the opening and closing movement, simple structure, small size, light weight, small flow resistance, flow coefficient, good sealing performance. The adjustment range. Execution units of the instrument in the automated control system; 2. By electro - pneumatic valve positioner, signal and compressed air as the driving force, to accept the control system input 0-10mA DC or 4-20mA DC current signal, the compressed air regulator to convert the pressure signal of the gas source input and output, change the angle of rotation of the valve plate (0-90 º at any angle), to better adjust the flow control parameters. 3. Solenoid valve, the valve position back to the hearing, AC220V or DC24V power supply voltage and compressed air power, to achieve a quick two off the control of the fluid medium.