VALVE Russian patent published in 2002 - IPC

FIELD: bypass of liquid from high-pressure cavity to low-pressure cavity. SUBSTANCE: valve has body 1 with inlet and outlet passages 2 and 3, respectively. Body 1 is provided with main shut-off adjusting member 4 made in form of stepped body of revolution which forms control cavity 5 together with body 1. Valve includes also control valve 6 whose inlet cavity 7 is connected with inlet passage 2 together with control cavity 5 of main shut-off adjusting member 4 by means of throttle passage 8 and outlet cavity 9 is connected with outlet drain passage 3. Control cavity 5 may be communicated with inlet passage 2 through inlet cavity 7 of control valve 6. Line 10 connecting outlet cavity 9 of control valve 6 with outlet drain passage 3 is provided with pressure valve 11 with normally open section; it is provided with control cavities 12 and 13 which are located oppositely relative to its spool valve. First cavity 12 is connected with outlet drain passage 12. EFFECT: enhanced reliability of hydraulic system. 6 cl, 3 dwg