WELL EXCAVATOR PLUNGER Russian patent published in 2000 - IPC

FIELD: devices used in production of oil and gas, particularly, in plants of plunger elevator. SUBSTANCE: plunger has stem with guides on its ends. Set of movable rings is located on stem middle part. Installed between ring set and guides are bushings with slide bearings on its ends. Outer surface of bushings has protrusions formed by three surfaces. One of them is spiral which converts axial motion into rotation of bushing. The second surface is designed for destruction by cutting of wax accumulations on tubing walls. The third surface closes the first and second surfaces over circumferences. EFFECT: increased efficiency of device operation due to improved cleaning of passage channel in tubing from high-melting waxes and hydrates. 3 cl, 2 dwg