SHUT-OFF ADJUSTING SINGLE-SEAT VALVE Russian patent published in 1998 - IPC

FIELD: shut-off and adjusting fittings for smooth control of liquid or steam flow rate. SUBSTANCE: valve has body with seat, inlet and outlet branch pipes, cover with gland unit, drive, stem connected with shut-off member which is provided with circular groove with seal in peripheral portion of shut-off member. Shut-off member has projection in form of convex body of revolution, for example, truncated elliptic paraboloid. Groove for seal is shaped in form; seal is made from high-temperature rubber or fluoroplastic. Seat has form of circular projection with profile of rounded-off "tooth" in radial section; seat is made from stainless steel. Ratio of rounding-off radius of "tooth" R_t to diameter of passage area of seat D_s is within . Besides that, gland unit is provided with set of shaped sealing rings and spring-loaded bellows. EFFECT: high tightness for an extended period of time. 2 cl, 1 dwg