Big-caliber detachable flange seal structure applied under low-temperature vacuum pressure environment

The utility model discloses a big-caliber detachable flange seal structure applied under a low-temperature vacuum pressure environment. The big-caliber detachable flange seal structure comprises an upper flange and a lower flange which are fixedly connected with each other. An annular boss and an annular upper carrier-free (CF) cutting edge are respectively arranged at the bottom of the upper flange, and an annular groove and an annular lower CF cutting edge are respectively arranged at the bottom of the lower flange. The annular boss is matched with the annular groove, and indium wires are arranged in the annular groove. The upper annular CF cutting edge is matched with the lower CF cutting edge, and a red copper sealing gasket is arranged in the annular lower CF cutting edge. Through utilization of double sealing of the red copper sealing gasket and the indium wires, the problems that a conventional seal structure only is suitable for a small-caliber detachable flange, and pressure of low-temperature liquid can not be higher than 0.5 million pascal (M Pa) or the low-temperature liquid is not permitted to have pressure. Meanwhile, the tedious process that the detachable flanges are frozen firstly and then bolts are fastened again can be avoided through the big-caliber detachable flange seal structure.