Tetrafluorin butterfly valve line is in order to adapt to some have strong acid, strong alkali corrosive environment, petroleum, chemical, food and other special field needs, in the conventional butterfly valve valve and the valve plate lined with ptfe, so that the medium and body isolation, to achieve the anti-corrosion effect. It can replace the stainless steel valve body under normal conditions and has higher cost performance. Butterfly valve disc installed in the pipe diameter direction. In the butterfly valve body cylindrical channel, disc shaped disc around the axis of rotation, rotation Angle between 0°~90°, rotation to 90°, the valve is fully open.