Combined type filters offer the most recent technology in multi-filtering for natural gas, by combining in a single housing the clone type pre-filtration system with the cartridge type final filtration system. During prefiltration, a large part of pollutants is removed and drained, while in final filtration the filtering cartridges, built of cellulose membrane or synthetic micro-fibers, assure excellent results with solids, or liquids’ coalescence. This filter model is versatile, requires little installation space and provides large savings in relation to traditional double filtration system.