In order to prevent paraffin separation and clogging of the filter at low ambient temperatures, pre-warming with electric heating elements or recirculation of fuel that has been warmed by the engine is used in our fuel filters.
For newer generations with even higher requirements, MAHLE has opted for two separate filter stages during water separation.
The first filter phase consists of a cellulose filter medium with an untreated melt-blown contact surface for increasing the contaminant absorption capacity. This melt-blown contact surface optimally causes the many small droplets to coalesce into larger ones. The particulate filter in the shape of a pleated star even agglomerates the finest water droplets.
The second filter phase consists of a water separator, whose hydrophobic fabric with a mesh width of 25 µm divides the barely stable emulsion, thus separating the water. As this occurs on the clean side of the filter, it is referred to as clean-side water separation.
