CUT-OFF VALVE Russian patent published in 1998 - IPC

FIELD: gas and oil producing industry. SUBSTANCE: arranged in body is cylindrical sealing insert whose through holes coincide with straightway passages of body. Insert is provided with cylindrical movable shut-off member mounted inside it; shut-off member have bypass passages for communication of inter-tube space with lower cavity of hydraulic cylinder which is mounted perpendicularly relative to horizontal axis of body and is divided into two cavities; it is rigidly connected with shut-off member by means of piston. Shut-off member and piston are pressed by spring to position at which holes of insert are closed. Hydraulic cylinder is made from nonmagnetic material and is provided with sensitive element, for example, hermetically-sealed reed relay mounted on its outer surface for check of position of shut-off member. Cover of cylinder is provided with discharge hole. EFFECT: enhanced reliability. 5 dwg