OIL-WELL SUCKER-ROD PUMP Russian patent published in 2001 - IPC

FIELD: oil industry. SUBSTANCE: proposed oil-well sucker-rod pump has intake valve and drain device. Intake valve is made in form of spool pair whose cylinder is furnished with seal made up of set of sealing rings lapped to each other at end faces and pressed to sealed surfaces by flexible holder. Spool is made in form of cup with through ports on cylindrical generatrix. End face of cup is flexibly closed on housing. Threaded drain hole is made in bottom. Drain device is made in form of threaded plug installed in hole of cup from side of its space and furnished with faceted extension passed through hole for wrench to turn out the plug. Cup is locked from turning. EFFECT: improved reliability of oil-well sucker-rod pump. 4 dwg