Investigation of Contact Characteristics and Sealing Performance of Metal Seals in All-Metal Angle Valves

The sealing performance of metal seals in all-metal angle valves significantly affects their reliability and the safety of the entire fluid system. This study investigates a DN40 all-metal angle valve, analyzing the contact characteristics between the sealing ring and valve head cone surface, focusing on microscopic surface morphology. Finite element analysis and laboratory experiments were conducted on sealing rings with surface roughness values of 1.6 μm, 0.4 μm, and 0.2 μm. Additionally, leakage rates were measured experimentally to verify the model’s accuracy. The results show that reducing surface roughness to 0.2 μm lowers the valve’s leakage rate to 1.28 × 10−11 Pa·m3/s, meeting ultra-high vacuum requirements. Compared to 0.4 μm, the leakage rate of 0.2 μm was reduced by 45.9%. The sealing performance of the 1.6 μm metal sealing ring was relatively poor and failed to meet ultra-high vacuum requirements. These findings align well with theoretical predictions. Further analysis revealed that lower surface roughness increases the effective contact area between the sealing ring and valve head cone, reducing leakage and improving overall sealing efficiency. These results suggest that optimizing surface roughness in sealing ring design can enhance valve performance, improving reliability and efficiency in industrial applications, particularly in vacuum systems and high-performance fluid control.