SHUT-OFF THROTTLING VALVE AND ITS BODY Russian patent published in 2003 - IPC

FIELD: manufacture of fittings for thermal power plants, steam central power plants and heat power plants for control of water flow in starting and transient modes. SUBSTANCE: proposed shut-off valve has body with cover and inlet and outlet branch pipes; body is provided with two-stage spool valve. End face of spool valve seat is provided with sealing surface of first shut-off stage of spool valve. Hole of seat has cylindrical sealing surface of second throttling stage of spool valve. Shut-off stage of spool valve is connected with drive rod. Free end of said stage is provided with cylindrical tail-piece. Bypass slots are made over generatrix of tail-piece. Diameter of tail-piece is equal to diameter of straightway hole of seat. Outlet branch pipe is provided with throttling unit. Sealing surface of shut-off stage of spool valve is taper in shape. Other stage is made in form of sleeve whose open end is directed towards outlet branch pipe. Seat is provided with ports opposite outlet branch pipe. Wall of sleeve is provided with several bypass holes. Seat is made in form of hollow cylindrical part mounted in body for pressing it by cover. Body of shut- off throttling valve is provided with inlet and outlet branch pipes, end surface for mounting the cover and central passage for receiving the seat and drive rod of spool valve. Said passage is stepped in shape for resting of seat against one of stages and resting of cover against other stage. Circular groove is made in passage opposite outlet branch pipe. Proposed valve ensures three-stage killing of energy of working medium kept at high pressure of 9.8 Mpa and temperature of about 150 C and smoothing of flow at outlet of shut-off throttling valve. EFFECT: enhanced efficiency. 7 cl, 1 dwg