Cylindrical valve body structure manufacturing process is relatively simple, easy to assemble and locate, billet manufacturing required mold is simple, and easy to use the support plate on the ball for fixing. The structure of the process is better, easy to install the stem part of the valve, for large diameter fully welded ball valve is particularly suitable. (Two-body for small-diameter fully welded ball valves, three-body for large-diameter fully welded ball valves)