Pneumatic soft-seal wafer butterfly valve pneumatic head-Shanghai Yuwang's butterfly plate is installed in the diameter direction of the pipeline. In the cylindrical passage of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis. The initial position of the valve is determined according to actual requirements. When the valve is rotated from the initial position by 90°, an action ends (from open to closed, Or from off to on), and vice versa, another action (from off to on, or from on to off) ends. 1. The pneumatic wafer butterfly valve is simple in structure, small in size and light in weight. It consists of only a few parts and is easy to install.