Abstract:Under the harsh working conditions such as ultrahigh pressure and large size,the conventional seals are prone to occur serious deformation,insufficient strength and leakage,which are difficult to meet the performance requirements.Therefor,Cring was selected as the object of study,and its adaptability under the background of ultrahigh pressure and large diameter seal was studied.A twodimensional axisymmetric model of metal C ring was established,and the compressionresilience of C rings with and without silver coating was analyzed by using the finite element method.The laws of Mises stress and contact stress under constant and variable conditions were analyzed,and the influence of different compression and external pressure on the seal characteristics was discussed.The simulation results are close to the experimental data,verifying the correctness of the theoretical model.The simulation results show that silver coating has little influence on the compression characteristics of C ring.The rebound ability of the cover ring is obviously worse than that of the spring,and the ultimate strength of the cover ring is more easily reached in the ultrahigh pressure environment,which makes it more likely to be damaged compared with the spring.The sealing ring has good safety and sealing performance when the compression amount is in the range between 065 mm and 085 mm.Therefore,C ring seal has good adaptability in large diameter vessels under ultrahigh pressure and meets the requirements of ultrahigh pressure seal.