| 摘要 |
<p>A pressure actuated seat ring for a disc valve has a tubular, relatively flexible portion extending axially from a radially thicker, relatively inflexible portion. The flexible portion of the seat ring extends circumferentially about the disc of the valve when the valve is closed and a cavity is formed about the flexible portion such that fluid pressure in the cavity tends to force the flexible portion of the seat ring against the disc. The ends of the cavity are vented to the flow passage of the valve at opposite sides of the disc and an elastomeric sealing ring mounted on the tubular portion of the seat ring is movable within the cavity in response to a pressure differential at the vents to seal the vent exposed to the lower pressure so that the larger pressure is transmitted to the cavity.</p> |
