A ball valve is a valve driven by a stem and rotated around the axis of the ball valve. It can also be used for fluid regulation and control. Hard-sealed V-type ball valve has strong shear force between V-type ball core and metal seat of hardfacing carbide, especially for medium containing fibers and micro-solid particles. In the pipeline, the multi-pass ball valve can not only flexibly control the confluence, diversion and flow switching of the medium, but also close any channel and connect the other two channels. Valves of this type shall generally be installed horizontally in pipes. Ball valves are divided into pneumatic ball valves, electric ball valves and manual ball valves according to the driving mode.