Ball valve

Claim 1

A ball valve for controlling liquid flow, comprising a tubular valve body, a ball rotatably mounted inside of said valve body and provided with a central through channel, a union positioned in each end of said valve body so as to be in slidable contact with said ball via a seat, and a body cap connected to each outer end of said union with a packing ring intervening therebetween for providing a water-tight seal, said union and said body cap having opposed end surfaces, said packing ring being accommodated in an annular groove recessed on at least one of said opposed end surface, said body cap being secured to said union by a cap nut engaged with a circumference of said valve body, whereby liquid flow passing through the valve is controlled by rotating said ball so that the direction of the channel of said ball is varied from a direction aligned with a longitudinal axis of said valve body to a direction perpendicular to said axis of said valve body, said union having, at the inner end thereof, an annular projection substantially filling an annular cavity between an inner wall of said valve body and an outer surface of said ball, said packing ring having the same inner diameter as that of said union and is provided with an annular rib to be accommodated into the entire length of said annular groove, said ball valve including a valve stem connected to said ball, said valve stem extending outwardly through said valve body, a portion of each annular projection located adjacent said stem when said channel is aligned with said axis.