Ball valve and gate valve are the same type of valve, the difference is that its closing part is a ball, the ball is rotated around the body core line to achieve the opening and closing of a valve. Ball valves are mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. Flange ball valve standard GB/T21465-2008 "Valve terminology" is defined as: the opening and closing parts (spheres) are driven by the valve stem and rotate around the axis of the valve stem.