Sealing assemblies for rotary ball valves

Claim 1

A rotary ball valve comprising a continuous tubular body which has a constant inner and outer diameter, an apertured ball in said body, and sealing assemblies for said ball, which assemblies include a seat ring to seal against the surface of the ball, a seat-retaining ring supporting said seat ring and having both a conical outer surface sloping outwards toward said ball and a cylindrical extension to the rear thereof, a wedge ring having a conical inner surface contacting said outer surface of said seat-retaining ring and a substantially radial rear face, a backing ring of such radial dimension that it abuts only said rear face of said wedge ring, said backing ring lying around said cylindrical extension, spring means for exerting pressure on said backing ring to press it against said wedge ring, and internal circlips within said body against which the spring means react to hold said assemblies against said ball.