ZDLW high-temperature butt welded butterfly valve has a simple structure, small volume, and light weight, consisting of only a few parts. And it can be quickly opened and closed by simply rotating 90 °, with simple operation, and the valve has good fluid control characteristics. When the butterfly valve is in the fully open position, the thickness of the butterfly plate is the resistance of the medium flowing through the valve body, so the pressure drop generated by this valve is very small, which has good flow control characteristics. Butterfly valves have two sealing types: elastic sealing and metal sealing. Elastic sealing valve, the sealing ring can be embedded on the valve body or attached around the butterfly plate.