PUB - Leakage of Metallic Ball Seat Valves with Anisotropic Surfaces

Correct valve selection creates safety. Due to different areas of application, specific requirements are placed on valves and their sealing effect. In a poppet valve, the connections are joined by placing or lifting off a sealing element. Valves are divided into two designs and are classified as spool valves and classic poppet valves. In spool valves, the flow is controlled by the spool, which can be longitudinal or rotary. The differentiation of poppet valves lies mainly in the shape of the sealing seat and the sealing element. A significant advantage of poppet
valves is that these valves achieve a hermetic seal.

Content

Authors: Fischer, Felix Justin; Bady, Dariush; Schmitz, Katharina

Metallic ball seat valves are an essential component of many hydraulic systems. They are used for many different purposes such as pressure relief valves or check valves. Despite their universal usage, their sealing mechanism is not yet fully understood. In previous works, a successful method for the simulation of the fluid leakage of metallic ball seat valves has been developed and confirmed experimentally. The method is based on Persson’s contact mechanics theory, which is based on surface roughness power spectrum C(q). This theory takes a wide range of
roughness values at different length scales into account. The previous method has been restricted to isotropic surfaces, but most surfaces of practical interest are highly anisotropic. A method for the calculation of pressure flow factors using Persson’s method is presented. Based on these, a model for the leakage calculation can be developed. The simulation results are validated using an experiment.