GAS CUTOFF VALVE Russian patent published in 2002 - IPC

FIELD: mining industry, particularly, gas production. SUBSTANCE: gas cutoff valve includes gate and closed chamber located above gate. Movable bushing with circular piston is connected with gate with possible its switching over to closed position with piston movement in direction of chamber volume increase. Chamber has throttling holes communicating chamber space with cavity of string located above gate. Cutoff valve has float and the second gate connected with float. The second gate is installed for shutoff of fluid passage to closed chamber with float moving upward. EFFECT: autonomy of device and possibility of its installation in the immediate vicinity of bringing inflow zone; higher efficiency and operating reliability. 2 cl, 3 dwg