The invention discloses a
leak rate testing device and a
leak rate testing method for a
composite material flange in a
liquid oxygen temperature environment. The
leak rate testing device comprises a
helium tank group decompression device, a low-temperature
flange testing device, a
liquid nitrogen storage device, a
helium leak rate testing device and a low-temperature container, the low-temperature
flange test device comprises a
composite material flange, an inner cylinder, an inner cylinder bottom cover and an outer cylinder, the inner cylinder bottom cover is positioned on one side of the opening end of the inner cylinder and is connected with the
composite material flange; the inner cylinder is arranged in the outer cylinder and is connected with the outer cylinder; a gap is reserved between the inner cylinder and the outer cylinder;
helium is injected into the inner cylinder by the
helium cylinder group pressure reducing device; the low-temperature flange test device is arranged in the low-temperature container, and the
liquid nitrogen storage device injects
liquid nitrogen into the low-temperature container; and the helium
leakage rate testing device is connected with the low-temperature flange testing device. The invention plays an important role in developing the use of the composite material flange on the
rocket liquid oxygen storage tank, and has the advantages of strong
operability, high safety and reliable test result.