Two-phase filtration kits designed for the fuel (diesel, petrol, kerosene and oil) filtering of buried or aerial tanks, getting the microfiltered fluid free of impurities. First filtration phase of 50 µm (micron) Second filtration phase for water absorption and impurity filtration of 15 µm (micron) Special superficial interior and external finish against corrosion. The kits are composed of: 1 fixed platform 2 manual drain valves to eliminate the residual air 2 differential manometers which show when the filter has to be replaced or cleaned 2 outlets for the filtered liquid sampling 2 inlets for the connection of compressed air to clean the filters without being disassembled 1 Ø150x458 mm impact filtering element of 50 µm (micron) 1 final element of absorbent paper of 15 µm (micron)