VALVE UNIT FOR FLUID MEDIUM, POSITIONING MECHANISM OF STRAIGHT-FLOW VALVE AND USE OF VALVE ASSEMBLY FOR FLUID MEDIUM FOR CONTROL OF STRAIGHT-FLOW VALVE

摘要

FIELD: valves.;SUBSTANCE: group of inventions relates to a fluid valve assembly, as well as to a straight-flow valve positioning mechanism and to application of a fluid valve assembly for controlling a straight-flow valve. Valve assembly for fluid comprises valve body with central bore, having inner chamber of inlet pressure, external chamber of inlet pressure connected with input inlet pressure line, drive chamber and outlet chamber. Assembly comprises a rod configured to axially move in the central bore and driven by axial control force and axial counterforce acting on the rod. Assembly comprises a metering edge and a counter metering edge located coaxially with the rod and controlled by a rod and configured to control the fluid flow from the external chamber of input pressure into the drive chamber and from the drive chamber to the outlet chamber, respectively. Assembly comprises sealing element located coaxially with rod between external chamber of inlet pressure and internal chamber of inlet pressure. At that, internal chamber of inlet pressure is made with possibility to retain input pressure creating axial counterforce acting on rod in internal chamber of inlet pressure; and means for limiting fast changes of inlet pressure in inner chamber to prevent uncontrolled movement of rod.;EFFECT: creation of valve assembly for fluid medium of new design.;18 cl, 22 dwg