Effect of Swelling Behavior of Rubber Rings on the Sealing Performance for 70MPA Hydrogen Pressure Reducing Valves

Abstract The sealing structures of 70MPa hydrogen pressure reducing valves (HPRV) are important for avoiding leakage. A novel constitutive model considering rubber hyperelasticity and hydrogen-induced strain was built. The model describes the mechanisms of how hydrogen swelling influences sealing performance. Utilizing the finite element software (ABAQUS), in tandem with the user material subroutine (UMAT), a numerical model of the rubber O-ring sealing apparatus under high-pressure hydrogen is developed. The model emphasizes the swelling behavior. Contact stress and Von Mises stress of rubber rings are analyzed to characterize the sealing performance. The influence of various parameters on the sealing performance are discussed respectively, including the hydrogen pressure and the seal gap. The results show that the optimal pre-compression ratio for the structure analyzed is approximated at 5%. Compared to traditional design, this design not only enhances the seal length, but also attenuates the Von Mises stress at the stress concentration point.