Cartridge filtration units generally operate most effectively and economically on applications having contamination levels of less than 50 to 80 ppm. For heavier contamination applications, cartridges are normally used as final polishing filters. In the following the basic systems of cartridge filters are listed Micron cartridge filters are used to remove micronic (measure equal to 0.000039 inches) dust particles, colloids and other physical contaminants from the water. Micron cartridge filters come with a housing and filter elements. Micron filters are available in various micron ratings like 0.1 / 1 /2 / 5/10 up to 40 microns. Polypropylene filter yarn is carefully wound onto the core in a specific pattern and density to meet the micron particle size requirements. Micron cartridges consist of extremely fine micro fibres spun into a multi-layer inert filter medium with optimized pores and graded density media enabling excellent particle retention and high dirt-holding capacity. Suitable material of construction ensures wide chemical compatibility and very low media migration. Micron filter cartridges are cylindrical filters consisting of a filter media arranged in multiple-layers supported by a perforated polypropylene core and an outer protective sleeve. The packs are sealed in to the required end cap. The cartridges are manufactured to provide a large surface area in a small volume resulting in high throughputs coupled with lower pressure drops and longer life. String wound filter cartridges are referred to as depth filters since particulates are trapped within the full volume of depth of the cartridge. The size of the particles filtered by micron filters depend on the rating of the cartridge. Safe operating temperatures for polypropylene filter cartridges are up to 80 degree F. MF operates at ultra-low pressure conditions.