The Oil Water Coalescer Filter Cartridge has multiple layers of filter media, the pore size of which increases gradually. Due to the difference in surface tension, the oil quickly passes through the filter layer, while the water is much slower; and because the coalescing filter element uses hydrophilic materials, tiny water droplets are adsorbed on the surface of the filter layer and cause water droplets to coalesce. Affected by kinetic energy, small droplets race through the openings, gradually converge into large droplets, and settle under the action of gravity to separate from the oil.