| 摘要 |
A multiposition choke valve assembly comprises: (a) a valve body defining an interior chamber and inlet and outlet flow ports communicable with that chamber, (b) a valve stopper sub-assembly movable axially longitudinally in the chamber, the sub-assembly including an axially extending stem, an axially extending sleeve, an annular section located between the stem and sleeve, and an annular seal on the annular section and exposed at the section periphery, (c) the sleeve forming multiple through openings and having a retracted position in which the flow passes with relatively lesser velocity past the seal and then forwardly to pass via such openings with relatively increased velocity into the sleeve, followed by generally axially forward flow toward the outlet flow port, (d) the sleeve having an advanced position in which the seal is radially compressed to engage a body bore, and the flow through the sleeve openings is blocked.
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