Poppet valve performance under cavitating conditions

Abstract

In fluid power applications, poppet valves are used to regulate flow rate or pressure by determining the flow areas for the hydraulic fluid, according to the proper control logics. The operating conditions may cause the onset of cavitation, with the possible alteration of the valve performance. This work aims at experimentally characterizing the behavior of a research-oriented conical poppet valve, exploring the effect of the feeding conditions on the flow characteristics of the valve. As a preliminary step, the research-oriented poppet valve has been designed according to the layouts found in the literature. Since the main interest is here focused on the small hydraulic power-packs, the valve size has been scaled down to meet their typical flow-rate range. Beside the research-valve design phase, a complete hydraulic test bed has been set up. Once the whole experimental facility has been completed, the assessment of the system has been made under stationary conditions. In this way, the pressure-flow characteristic curves of the valve were obtained for two configurations of poppet lifts. Subsequently, further tests were carried out in order to evaluate the test-bed capability to investigate the behavior of poppet valve under fluctuating pressure condition. This inlet condition is typical of small power-packs, where delivery volumes are small and the pump-induced pressure fluctuations are not negligible. Materials and adopted methods are described and discussed; discharge coefficients, cavitation inception and flow-rate-pressure characteristics are reported, highlighting the capability of the proposed approach.In fluid power applications, poppet valves are used to regulate flow rate or pressure by determining the flow areas for the hydraulic fluid, according to the proper control logics. The operating conditions may cause the onset of cavitation, with the possible alteration of the valve performance. This work aims at experimentally characterizing the behavior of a research-oriented conical poppet valve, exploring the effect of the feeding conditions on the flow characteristics of the valve. As a preliminary step, the research-oriented poppet valve has been designed according to the layouts found in the literature. Since the main interest is here focused on the small hydraulic power-packs, the valve size has been scaled down to meet their typical flow-rate range. Beside the research-valve design phase, a complete hydraulic test bed has been set up. Once the whole experimental facility has been completed, the assessment of the system has been made under stationary conditions. In this way, the pressure-flow chara...