The invention relates to a large-
caliber ultrahigh-pressure differential steam emptying valve. The large-
caliber ultrahigh-pressure differential steam emptying valve comprises a valve body, wherein aself-sealing
valve seat is arranged in the valve body, a maze sleeve and a pressing ring are sequentially connected to the self-sealing
valve seat, and the pressing ring, the maze sleeve and the self-sealing
valve seat are pressed in the valve body through a pressing four-
split ring; the upper end of the valve body is connected to a valve cover pressing plate, a self-sealing valve cover is arranged in the valve cover pressing plate in a penetrating mode, the sealing end of the self-sealing valve cover is connected to the valve cover pressing plate through a valve cover adjusting bolt and a valve cover nut, and a valve cover self-sealing ring is arranged between the sealing end and the valve body; and a valve cover four-
split ring which is located on the upper side of the sealing end of theself-sealing valve cover is arranged in the valve body, a stepped valve element is arranged in the pressing ring, the maze sleeve and the self-sealing valve seat, a valve element sealing mechanism isarranged on the outer side of the stepped valve element, the upper end of the stepped valve element is connected to a valve rod, the valve rod penetrates through the self-sealing valve cover to extend to the outside, and the valve rod and the self-sealing valve cover are sealed through a valve rod sealing mechanism. According to the large-
caliber ultrahigh-pressure differential steam emptying valve, the valve seat is detachable, mounting and maintaining are convenient, operation is stable, and sealing is firm.