Influence of normal force in metallic sealing

Abstract

Abstract Metallic ball seat valves are an essential component in almost every hydraulic system in the form of check valves. Despite their wide usage in real‐life applications, the physical sealing mechanism is not yet fully understood and still debated. One promising method is the contact mechanics theory which has been developed by Persson et al. for rubber seals. It can predict the leakage of rubber seals successfully, but its application for metallic seals, where plastic deformation plays an import role, has only been developed recently and is not yet fully validated. This theory is combined with surface scans of investigated seats and simulations that are performed using the finite element method (FEM) for different geometric configurations. This combination allows an efficient calculation of the leakage of ball seat valves depending on their specific design and applied forces and pressures. In this work, the predictions by simulations according to Persson's theory are compared with experimental results. This comparison is done by analyzing the dependency of the leakage of ball seat valves in relation to applied normal forces and for different surfaces in contact. This validates the applicability of Persson's method in this field. The presented experimental method allows the measurement of the leakage of ball seat valves under realistic conditions.

Keywords

• asperities
• ball seat valve
• leakage
• sealing
• surface