BOREHOLE PLUNGER PUMP AND PROTECTION METHOD OF UPPER PART OF PLUNGER AGAINST IMPACT OF PUMPED LIQUID Russian patent published in 2011 - IPC F04B47/00 

FIELD: engines and pumps.

SUBSTANCE: borehole plunger pump includes housing, pump chamber with suction valve and control chamber with drive liquid, which is interconnected by means of discharge valve to tubing string and separated from pump chamber by means of a partition. The cavity filled with buffer liquid is formed between pump chamber and control chamber so that hydraulic lock is formed. Lower part of plunger connected to rod string is located in control chamber. Upper part of plunger is arranged in separating chamber formed above control chamber and separated from the latter with a cylinder with at least one annular seal enveloping the plunger. Separating chamber is filled with buffer liquid with specific weight exceeding specific weight of pumped liquid.

EFFECT: higher operating reliability of borehole plunger pump and longer overhaul period of its operation.

13 cl, 2 dwg