Fuel filters detain pollution contained in gasoline or diesel fuel, and even are used in LPG systems, effectively protecting high-precision elements of the fuel system of internal combustion engines from rapid deterioration. Dust, rust from the inner walls of tanks, water, as well as microorganisms living in it, can cause rapid wear of injectors, pumps or valves of pressure regulators available in modern engines. Therefore, in each fuel system there are filters that are optimally adapted to the requirements of the engine, the quality of the fuel, as well as the envisaged operating conditions. The requirements for filters are very high. Modern engines require the capture of impurities of the order of 3-5 microns with an efficiency of over 90%. In order to meet these requirements, in many cases, several filters are installed in the fuel system. At the same time, unlike oil filtration, when filtering fuel, there are no by-pass valves that let the fuel flow when the filters are already clogged, since it is mandatory that only clean fuel enters the combustion chamber. So it’s better if the engine stops due to lack of fuel (clogged filters) than if it should work, fueled by unrefined fuel.