This study explores the sloshing phenomena that occur when transporting Liquefied Natural Gas (LNG) in membrane tank LNG carriers. The sloshing phenomenon becomes more important as the volume of the tank increases. The study presents an evaluation of a membrane-type LNG containment system with a capacity of 19,000 cubic meters, using the program ANSYS Fluent to construct the mesh and simulate the LNG sloshing motion. The impact pressure, which affects the tank wall strength and the vessel's stability, is investigated, and the study finds that liquid depth affects the higher impact pressure for circular motion in contrast to horizontal motion. The study also reveals that using a blanket over the liquid's surface can significantly reduce the higher impact pressure. These findings provide insights into how to successfully lower the impact pressure to ensure the structural integrity of the bulkheads in real-world scenarios.