Patent ID: 8979068
Filing Date: 2015-03-17
Classification: F16K

Abstract:
1. A differential pressure sealing device for use with ball valves having a moving ball with at least one seating surface, the sealing device comprising: a seating mechanism including a movable sealing ring positioned between a stationary inner ring and a stationary outer ring, the movable sealing ring having a moveable sealing surface that interacts with the at least one seating surface of the ball; a pressurizing system having an outlet port that communicates a supply of pressurized fluid through the stationary outer ring to an open cavity between the movable sealing ring and the stationary inner ring to exert a sealing force on the movable sealing ring to urge the sealing surface of the sealing ring against the at least one seating surface of the moving ball; and a bias member positioned between the stationary inner ring and the movable sealing ring to exert a bias force on a rear surface of the sealing ring opposite the sealing surface, wherein the bias member is a spring compressed between the rear surface and a stationary shoulder formed on the stationary inner ring, wherein the bias force is combined with the sealing force created by the pressurized fluid.