The high capacity I.C engines often have oil systems with two types of filters. One full-flow filter - all the oil pumped flows through, while the second is built into the system in parallel and about 10% of oil flows through it. This oil after being purified goes back into the oil sump. The full-flow filter functions as a coarse filter while the by-pass filter is the fine filter in this system. In the oil system, centrifugal filters are often applied as by-pass filters, where contaminants are separated from the oil in the centrifugal field of force. Filters are also used, made with a medium of special fabrics or filtering papers. The characteristic feature of by-pass filters with the medium is the amount of oil reduction during exploitation, which results from flow resistance increasing during the filter medium blocking. In some engines with full-flow/by-pass oil system, the can filters with two filtering cartridges (full-flow and by-pass) are applied. Such integrated filter systems take less space and its replacement is much quicker. The oil flow is divided in such filters into the main flow directed into the engine and by-pass flow, which after proper purifications flows back into the oil sump.