Pneumatic butterfly valve, Double Flange Butterfly Valve is type of resilient seated butterfly valves,with integral flanges cast on both ends.

same as all the other butterfly valves,it's a quarter-turn valve that rotates 90 degrees to open or close the media flow. It has a circular disc, also known as the butterfly, found at the center of the body that functions as the closing mechanism of the valve. The disc is connected to an actuator or handle through the shaft, which goes through from the disc to the top of the valve body.

Butterfly valve is also used as flow regulalting valve,if the disc does not rotate to a full quarter-turn, it means the valve is partially open

NORTECH Pneumatic butterfly valve, Double Flange Butterfly Valve is designed with long face to face,according to EN558-1 series 13. it can be used in many general applications such as in water distribution, water treatment, dams, power plants and in many other. The valve can be used as a stopper, a tap for discharging at the end of the pipeline, open/close and flow control. 

for large size pipeline,double flange butterfly valves are wided used.