DOUBLE ACTING BALL COCK FOR OPERATION AT HIGH PRESSURES Russian patent published in 2004 - IPC

FIELD: mechanical engineering; valves and fittings. SUBSTANCE: invention is designed for use as shutoff device in pipe lines transporting corrosive media or natural gas at high pressure. Proposed ball cock contains housing with inlet and outlet sections for medium. These sections communicate through dividing space. Ball-type shutoff member with through longitudinal hole is installed for turning in vertical plane through 90^o by means of drive shaft with handle. Two movable seats - seats flexibly loaded by pressing devices are located at both sides of shutoff member. One of seats-seals is arranged in cylindrical bore of housing, and the other is placed in inner cylindrical bore of movable connecting bushing with sealing ring on outer cylindrical surface. Support nut is conjugated with housing over threaded surface and it thrusts against ring step of connecting bushing. Diameters of inner cylindrical bores for seats-seals in housing and connecting bushing, diameters of hollow bowls in seats-seals and diameter of ball-type shutoff member are made to comply with the following relationships: D_b/D_ball = 0,95-1,1, D_b/D_bowl = 1,12-1,17, where D_b - are diameters of inner cylindrical bores for seats-seals in housing and connecting bushing, D_bowl - are diameters of hollow bowls in seats-seals, D_ball - is diameter of ball-type shutoff member. Depth of bore for seatseal is H = (0,3-0,34)D_b, mm. Width of seat-seal is B=H+(0-0.5)mm . Guaranteed ring clearance is made on section from end face of connecting bushing from side of mounting of seat-seal to beginning of radial ring groove for seal on outer cylindrical surface between corresponding surfaces of through channel of housing and connecting bushing. Said clearance is 2-2.2 times greater than ring clearance between corresponding sealing surfaces of through channel of housing and connecting on section located at other side of radial ring groove. EFFECT: increased reliability and sealing of ball cock, prevention of contact jamming of stainless steel parts to provide repairability of cock. 3 dwg