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