The Belgian railway company NMBS NV uses in one of its central workshops an Ultra Violet (UV) disinfection unit also called UV sterilizer. The sanitary water is thereby disinfected and safe for consumption. To prevent fauling of the installation and UV lamps a CleanFlow self-cleaning filter is installed in front of the UV system. As an additional advantage the efficiency of the UV radiation is increased because of this filter. Less UV light will be captured or reflected by dirt particles in the water since the particles are removed by the CleanFlow filter. The filter does not require opening for cleaning due to its self cleaning mechanisme and as such no maintenance.