Dart Valves for Bypass Plungers

摘要

A bypass plunger combines a unitary or one-piece hollow body-and-valve cage, retains a dart valve within the valve cage portion of the hollow body using a threaded retaining nut secured by crimple detents. A series of helical grooves surround the central portion of the outer surface of the hollow body of the plunger to control spin during descent. A canted-coil-spring disposed within the retaining nut functions as a clutch. The valve cage includes ports that may be configured to control flow through the plunger during ascent. Other embodiments include clutch assemblies using canted-coil springs with split bobbins, and valve stems surfaced to achieve specific functions. Combinations of these features provide enhanced performance, durability and reliability at reduced manufacturing cost, due primarily to the simplicity of its design.

主权项

1. A dart valve for a bypass plunger, the dart valve disposed to move reciprocatingly within a valve cage of the bypass plunger between seated and unseated positions and constrained by a clutch mechanism within the valve cage or its retaining nut, comprising:
a poppet valve comprising a valve stem and a valve head; a valve head connected to one end of the valve stem, the valve head including a sealing face to make sealing contact with a valve seat within the bypass plunger; and the valve stem includes a predetermined surface profile for moderating tension produced by the clutch mechanism during the reciprocating motion of the poppet valve.