| 摘要 |
<p>A tapered plug valve comprises a casing having a passageway therethrough for the flow of fluid and a tapered bore intersecting the passageway. A tapered plug is rotatably mounted in the tapered bore and is adapted to block the passageway when the valve is in a closed position. The plug has a bore which is adapted to connect and be in communication with the passageway when the valve is in an open position. The plug and the casing define an apex chamber at the small end of the tapered plug and a base chamber at the large end of the plug. A seal is provided at the large end of the tapered plug to sealingly divide the base chamber into a first and second cavity. A pressurized medium is ported into the apex chamber and the second cavity and the first cavity is vented to atmosphere. The radially extending area of the end of the small end of the tapered plug against which the pressurized medium acts is greater than the radially extending area of the end of the tapered plug in the second cavity against which the pressurized medium acts whereby the resulting force along the longitudinal axis of the plug is in the direction toward the large end of the tapered plug.</p> |
