OPENED CHECK VALVE Russian patent published in 2009 - IPC F16K15/18 

FIELD: mechanics.

SUBSTANCE: invention is designed for controlling and protecting hydraulically the powered support in underground working. Communication between load cavity (34) and connection cavity (34) in opened checked valve is closed by check valve piston (35) and opened by displacing piston (26). The piston (35) of check valve, relief piston (19) and piston (26) with control stem are arranged concentrically to each other with regard to valve axis, which is common for them. The control stem (32) passes through the piston (35) of check valve so that it can slide inside the said piston ensuring sealing with it. To open check valve, control stem takes up the piston bottom by means of circular ledge. The piston (35) of check valve is loaded in the closing direction by the effort of own connecting spring. The relief piston (19) is installed on the valve axis so that it can performed directed motions independently from the check valve relative to the free end of control stem (32).

EFFECT: improved reliability and extended service life of valve operation due to practical separation of check valve from relief valve.

12 cl, 4 dwg