The stainless steel flange leaks due to improper connection or long service life of the stainless steel flange, so users don't have to panic. Look at the leak first. Because the gap between stainless steel flanges is very small, it is usually impossible to eliminate leakage by injecting sealant into the gap. The sealing construction method is based on the field investigation of the leakage site. In order to achieve limited plugging, the method of fixing fixture is used to contain the leakage point, forming a sealed cavity, and sealant is injected to eliminate the leakage. The fixtures on one side are all customized. The fixtures must first contain leakage points. The first point is to establish a sealed cavity between the valve body flange and the pipe flange connection nipple flange. In order to prevent the potential gap between the valve body and the flange from leaking again due to pressure suppression, an annular cavity is set at the joint between the fixture and the outer edge of the valve body flange for glue injection. Because the fixture of variable diameter flange is easy to move to the side of small diameter flange during injection, the limit measure of tooth contact clamping is adopted. During operation, after the sealant is cured and the effect is observed, local injection compaction is carried out to prevent stress relaxation, and then the injection hole is closed.