Fabricated ball valve

Claim 1

In a valve of the rotary ball type, a valve body having flow passages adapted to be connected to associated piping, a rotatable ball valve member within the body having a port adapted to register with the flow passages for open position of the valve, the body including a main part in the form of a cylindrical pressure resisting shell surrounding the ball and generally annular in transverse section, the shell being formed of a plurality of segments Secured together by spaced longitudinal parallel weld connections, one segment being a flat mounting plate of uniform thickness disposed between the longitudinal edges of two adjacent segments, said two adjacent segments having a uniform wall thickness and being segments of a cylinder; said plate extending the length of the shell and having its longitudinal parallel edges welded to the edges of the adjacent segments, aligned trunnion means on the ends of the ball, bearing means carried by the mounting plate and serving to journal one of said trunnion means within the shell, additional bearing means for journalling the other trunnion means, the body also including end portions secured to the ends of the segments of the main body part for making connection with associated piping, one of said end portions comprising an annulus secured to the corresponding end of the shell, said annulus serving to mount sealing means forming a fluid-tight valve seal between the ball and the body for closed position of the valve, a conical shaped section having its large end secured to the outer margin of said annulus by welding, and a cylindrical pipe section disposed within the conical section and having its one end secured to the small end of the conical section by welding and having its other end secured to the annulus by welding, said annulus having a pressure equalizing duct extending through the same to establish communication between the space surrounding the sealing means and the space between the conical and cylindrical sections.