| 摘要 |
<p>A ball valve structure (10) having a valve seat assembly (46) positioned in annular seat pockets located in a flow passage (14) on opposed sides of a ball valve member (18). Each valve seat assembly is mounted for limited longitudinal movement toward and away from the adjacent ball valve member (18) and spring means (54) are placed within the seat pockets behind the valve seat assemblies to urge the assemblies toward and into intimate contact with the ball valve member. The valve seat assembly includes inner and outer annular concentric seat rings (48, 50) with a resilient sealing ring (52) secured therebetween. The inner annular seat ring has a flared end (64) which fits inside the outer seat ring and energizes or deforms the sealing ring (52) held therebetween, thereby, securely retaining the sealing ring between the seat rings and preventing the introduction of line pressure behind the sealing ring to possibly extrude the sealing ring from its position within the seat rings. The co-acting seat rings deform the sealing ring such as to provide a protruded annular sealing portion (96) which extends beyond the end boundaries of the sealing ring facing the ball valve member so that upon intimate contact with the ball valve member the protruded sealing portion (96) provides a high pressure sealing element to prevent pressurized fluid from escaping from the flow passage of the ball valve structure.</p> |
