| 摘要 |
<p>A balanced sleeve control choke includes a choke with inlet and outlet flow passages intersecting in a cylindrical flow chamber. A balanced external sleeve and cage trim configuration which vents downstream pressure to a balance chamber within the choke body includes an external sleeve with a wear sleeve of tungsten carbide shrink fitted therein is reciprocable within the flow chamber to control flow between the inlet and outlet flow passages. The external sleeve is closed at one end with a stem extending therefrom which is reciprocated by a handwheel operated travelling nut assembly. The external sleeve telescopes over a flow cage of composite construction secured within the flow chamber with a portion of the flow cage constructed of tungsten carbide with pressure balancing ports therethrough. The external sleeve has parts disposed within its wall which communicate downstream pressure to a balance chamber disposed thereabout. The flow cage has a seal neck extending from a closed upper end with a seal assembly disposed thereon which seals within the external sleeve and acts in conjunction with the balance chamber to eliminate any pressure forces on the travelling nut assembly.</p> |
