SUBSURFACE ISOLATING VALVE Russian patent published in 1998 - IPC

FIELD: oil production industry. SUBSTANCE: this relates to devices used for closing well bore before carrying out repair operations. Valve has body which accommodates spool with central passage which is open at top, and radial passages. Body is made with stop. Spool is provided with thrust shoulder in its lower part. Spool and body form together circular space which accommodates sealing member being of toroidal configuration and which can displace without sliding relative to body and spool. Non-return valve is seated in central passage of spool and is connected with fixing unit through quick-release joint. This unit is rigidly secured in body and can be fixed in position "Open" or "Closed" at various operating modes of creating control pressure. EFFECT: higher efficiency. 4 cl, 2 dwg