REGULATING VALVE Russian patent published in 2002 - IPC

FIELD: power mechanical engineering; control of pressure at turbine outlet. SUBSTANCE: regulating valve includes shut- off member made in form of piston with profiled end bowl, contraction- diffuser seat with cylindrical section, sealing rings, rod and external cylindrical sleeve. Profiled end section of piston forms axisymmetric valve passage together with inlet section of seat; it contains perforated belt whose holes are found on diameter equal to (0,7÷0,8)D_m, where D_m is mounting diameter of valve. Diameter of holes is equal to 0,04÷(0,02+0,05)D_m at circular pitch of (0,02÷0,06)D_m. Transversal grooves, 1 to 1.5 mm in width and 4 to 5 mm in depth are bored on diameter (0.2-0.5) of mounting diameter of valve normally to surface. EFFECT: reduction of pressure fluctuations in flow of steam arising in forming of jet flow which reduces restoration of pressure in diffuser of seat impairing reliability of valve and operation of first stage of turbine. 3 cl, 2 dwg