Damage Analysis of Thread Connection Sealing Ring

Mechanical damage failure occurred to a thread connection seal ring of an aircraft. Through appearance inspection, fracture analysis, hardness testing and clearance measurement, combined with the structural characteristics and working force characteristics, the failure mode, cause and process of the sealing ring were studied in depth, and improvement measures to prevent re-failure were put forward. The results show that the failure mode of the rubber ring is gap bite damage, which was mainly related to its low hardness and large clearance. The design dimension of the chamfered edge of the top cover is smaller than the standard requirements, promoting the bite damage of the rubber ring. Controlling the clearance within 0.06 mm and moderately increasing the hardness under the condition that the other properties of the rubber ring meet the requirements can effectively prevent the occurrence of similar faults.