The filtration process is carried out at low pressures, off-line, cartridge pressures and is controlled between 1 and 4 bar with a 6 bar maximum. The long cellulose fibers attract the water like a sponge formed either through the combustion process or by condensation, whilst at the same time rejecting the larger oil molecules. As the oil passes through the cartridge, minute particles of wear metals, carbon and silicon are extracted from the oil by adhering to the many surfaces of the filter.