DOUBLE-ACTING BALL COCK FOR OPERATION AT HIGH PRESSURES Russian patent published in 2001 - IPC

FIELD: shut- off devices for pipe lines transporting corrosive media or high-pressure natural gas. SUBSTANCE: ball cock has body with inlet and outlet sections for passage of medium; the4se sections are brought into communication through cavity separating them. Ball shut-off member with through longitudinal hole is turnable in vertical plane at angle of 90 deg. by means of drive shaft provided with handle between OPEN and CLOSED positions of cock. At OPEN position, hole of shut-off member is coaxial relative to inlet and outlet sections and at CLOSED position, axle of hole of shut-off member is perpendicular to axis of body. Two movable seats-seals flexibly loaded by movable units are located on both sides of shut-off member and their central concave sections are in full contact with surface of shut-off member. One seat is mounted in cylindrical bore of body and other seat is mounted in cylindrical bore of movable threaded plug with sealing ring on outer cylindrical surface. Hold-down unit of seat-seal is made in form of flat gasket made from rigid flexible elastomer material Gasket is laid on side of bearing end of seat and is made rectangular in radial section with outer diameter equal to outer diameter of seat- seal and inner diameter in accordance with relationship out/in = 1,3..., where out is outer diameter of gasket and in is its inner diameter. Seat-seal is provided with cylindrical projection located concentrically on side of flat gasket; its outer surface forms guaranteed circular clearance with inner surface of gasket for its motion. EFFECT: enhanced reliability and simplified construction of ball cock. 3 dwg