Ultralow-temperature ultrahigh-pressure self-tightening type three-sealing-structure check valve

The utility model relates to an ultralow-temperature ultrahigh-pressure self-tightening three-sealing structure check valve, which comprises a valve body (1), a valve seat (2), a valve clack (3), a valve core (8) and a valve cover (14), and a novel energy storage lip-shaped sealing ring (9) is additionally arranged between the valve core (8) and a sealing ring (10) to realize the first sealing of the valve; the contact sealing surface of the sealing ring (10) and the valve core (8) generates hardness difference through surfacing hard alloy to realize secondary sealing of the valve; and the valve cover (14) compresses the combined filler (13) when being fastened by a full-thread bolt I (16), so that the third sealing of the valve is realized. The check valve adopts a self-tightening three-sealing structure, the problem that a middle channel of the check valve with the ultralow-temperature and ultrahigh-pressure self-tightening three-sealing structure is difficult to seal is effectively solved, the sealing forc