This study investigates the effects of gas-liquid phase transition on sloshing-induced impact pressures. We solved the governing equations for the conservation of mass, momentum, and energy, coupled with a transport equation for the volume fraction. The numerical model accounts for flow compressibility, surface tension, and phase change, with the latter implemented via a mass transfer model based on the Hertz-Knudsen-Schrage relation. Following validation against experimental data, the model was used to analyse the influence of flow compressibility and gas-to-liquid density ratios - representative of natural gas and hydrogen systems - on impact pressures. Our results demonstrate that compressibility, gas density, and phase transition significantly alter the gas-liquid interface and, consequently, the resulting impact pressures. Specifically, gas compressibility was found to substantially reduce peak impact pressures. As gas density increases, the deformation of the liquid-gas interface changes, further reducing pressure peaks. Moreover, condensation during the impact phase leads to a considerable reduction in maximum pressure, while subsequent pressure fluctuations are strongly damped by the vaporization process. For a comprehensive discussion of these phenomena, the reader is referred to [1] and [2]. REFERENCES [1] A. Peters, A., O. el Moctar. Effects of phase transition and fluid properties on sloshing- induced impact pressures. Journal of Fluid Mechanics, Volume 1020, A27 (2025). https://doi.org/10.1017/jfm.2025.10643 [2] S. Rezaee, E. Kadivar, O. el Moctar. Molecular Dynamics-Based Approach for Laser-Induced Cavitation Bubbles: Bridging Experimental and Hybrid Analytical Computational Approaches. Langmuir 2025, ACS, American Chemical Society. https://doi.org/10.1021/acs.langmuir.5c00857