Manual ball valves rely on rotating the valve core to make the valve unblocked or blocked. The ball valve switch is light, small in size, can be made into a large diameter, reliable in sealing, simple in structure, easy to maintain, the sealing surface and the spherical surface are often in a closed state, and it is not easy to be eroded by the medium. It is widely used in various industries. The ball valve is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline.