VALVING DEVICE FOR FLOW REGULATION Russian patent published in 1997 - IPC

FIELD: oil production industry. SUBSTANCE: valving device has hollow body with through-passages, sealing collars on body, main and auxiliary isolating members rigidly connected by their upper ends with body, and by their lower ends they are connected with rod. Isolated chamber is formed between them. Also provided are lock, stem, and chamber above main isolating chamber which is filled with compressible working medium. Installed in body is additional isolating member which together with additional isolating member creates chamber which is filled with liquid. Stem can be made hollow and have radial passage under auxiliary isolating member. Isolated chamber between main and auxiliary isolating members can be filled with liquid. Additional lock can be installed in body rigidly connected with upper lock through additional stem. Both locks when found in extreme lower position can isolate space between locks and body from space which is created above and below locks. Diameters of locks are equal. With locks in extreme upper position, cross-sectional area of passages in body above lower lock is larger than axial cross-sectional bore area in body between locks and this bore area is larger than cross-sectional area of passages in body below upper lock. Cross-sectional area of passages in body under lower lock is less than minimal cross-sectional area of axial through-passage in body. EFFECT: higher efficiency and reliability in operation. 4 cl, 3 dwg