VALVE FOR WELL OPERATION Russian patent published in 1995 - IPC

FIELD: oil producing industry. SUBSTANCE: valve for well operation has hollow body with passing channels and seals. Installed in body is rod with locking member rigidly connected with flexible member and charging unit. Valve is provided with, at least, two locking members arranged successively along body longitudinal axis and interconnected by rods. There are tight partitions installed between additional second and subsequent locking members. Made in body between each additional locking member and partition are additional passing channels. Besides, valve has rod retainer. When pressure rises, axial force reaches definite level and locks move upward. Rod is fixed. Valve is in open position until pressure drops to preset value determined by the difference between force of flexible member directed downward and retainer resistance. EFFECT: higher efficiency of oil well operation due to increased flow area of valve with its limited diameter. 1 dwg