Between flange ball valves with fixed-unstressed seals

Claim 1

A ball valve comprising: a valve body having an upstream end face, a downstream end face, and a bore extending therethrough intersecting said end faces; a valve ball disposed in said bore, said ball having a port extending therethrough and rotatable between an open position wherein said port and bore are aligned to a closed position wherein said port and bore are disaligned, the diameter of said ball measured along said port, being greater than the length of said body; operating means in said valve operably connected with said ball for rotating said ball between said open and closed positions; a pair of flanged connecting members, each having an end face thereon and an opening extending therethrough intersecting said end face, the end faces being disposed relatively adjacent the end faces on said valve body with said openings aligned with said bore; an annular seat-seal member at each end of the valve body, each having an axial flange portion extending into said bore and carrying a first seal on one side thereof extending partially in and partially out of the respective end of the valve body and arranged to sealingly engage said valve ball, a second seal on the opposite side thereof sealingly engaging a respective end face on one of said connecting members and having an outer diameter substantially equal to the diameter of said bore, said annular seat seal member having an annular portion extending outwardly and disposed between and in engagement with one of the end faces on said valve body and the end face on one of said connecting members; and, connecting means extending between the flanges on said connecting members for assembling said valve, said connecting means exerting a force on said connecting members that is carried as a compressive load by said valve body through the annular portion of said seat-seal members, thereby avoiding distortion of said seat-seal members.