| 摘要 |
<p>PLUG VALVE A tapered plug valve comprising a casing having a passageway therethrough for flow of fluid and a tapered bore intersecting the passageway, a taper plug rotatably mounted in the tapered bore adapted to block the passageway in valve closed position of the plug and the plug having a port adapted to connect and be in communication with the passageway in valve open position, the plug and casing defining a chamber at one end of the plug, a stem rotatably mounted within the casing and mechanically coupled to the plug to rotatably drive the plug, the casing having an annular rib surrounding the stem at one end of the chamber, the stem having an annular rim thereon and located on the portion of the stem which is in the chamber, an annular thrust bearing and seal surrounding the stem and abutting the opposed lateral faces of the annular rib and the annular rim to provide a seal therebetween.</p> |
