FLUSH VALVE Russian patent published in 2009 - IPC E21B34/06 E21B37/00 

FIELD: mining.

SUBSTANCE: valve consists of connected with flow string (FS) cylinder body with radial openings, and of movable spring loaded pressure tight bushing placed in body and forming plunger pair. When a well is operated with a not-immersed sucker rod pump, the valve is equipped with a rod with a coupling intended to free movement in the internal part of the valve and connecting the plunger of the not-immersed sucker rod pump with bars tied with a cable suspender of a pumping unit. Also the valve is equipped with the second mandrel sub connecting its body with a lifting branch of the not-immersed sucker rod pump. Internal surface of the pressure tight bushing has a section of a conic shape. The coupling is located on a rod with consideration of depth of the suspender of the not-immersed sucker rod pump and stretching, caused by weight of bars, at a distance from the said section of the conic shape chosen so, that at operation of the pump the said coupling will not reach the said section and facilitating support of the coupling on this section at release of the rod connected to bars, from the cable suspender of the pumping unit to displace pressure tight bushing of the valve till coinciding with radial openings in the body of the valve and opening communication of the FS cavity with annular space.

EFFECT: reduced consumption of hot oil used for flushing, improved conditions of oil lifting from pump to well head, and increased operation life of immersed equipment between flushings.

2 cl, 1 dwg