An oil-water separator is a fuel filter primarily designed to remove water from fuel, thereby reducing nozzle malfunctions and extending the engine's lifespan. It separates water from the fuel, allowing it to burn more completely in the engine cylinders, resulting in improved engine performance.

Oil-water separators are used in conjunction with dust collectors. Their primary function is to separate water and oil from gases, utilizing the density difference between water and fuel to remove impurities and moisture through gravity settling. This ensures that the gas entering the electromagnetic pulse valve is cleaner. The oil-water separator also serves other purposes, such as preheating fuel to prevent wax precipitation and filtering out impurities. It can only separate engine oil from the water in the engine oil, which has a certain effect on improving engine oil combustion.