Study on Sealing Performance of Spring Energy Storage Seal used for Ultra High Pressure Throttle Nozzle

Through the combination of experiment, simulation and verification, this study successfully developed a spring energy storage seal ring, which can withstand the pressure of 175 MPa and the working temperature of -46 ° C to 180 ° C, showing significant application potential. Firstly, the constitutive model of the sealing material (PTFE and its modification) at -46 ° C, 20 ° C and 180 ° C was determined by compression experiment; The finite element analysis was carried out, and the effects of the angle of the support ring, the interference of the inner and outer lips and the angle behind the lip on the sealing performance were analyzed. The results show that the design angle of PEEK gasket suitable for the seal ring is 40 °, and the seal ring material is 10C-PTFE; In order to ensure that the contact stress is greater than 175MPa and the equivalent force is less than the yield strength, the margin of the inner and outer lip of the seal ring is 0.25mm and 0.2mm respectively, and the rear angle of the inner and outer lip is 9 ° and 11 ° respectively. Based on these findings, a spring energy storage seal ring for throttle valve was manufactured. In the 175MPa hydraulic tooling test, the maximum pressure drop is 1.75MPa. In the gas seal test of natural gas wellhead throttling nozzle, the pressure change is 0.4MPa at 20 ℃, 0.7MPa at 180 ℃, and 1.1MPa at -46 ℃.