Filter cartridge with series elements for chemical and mechanical filtration

A filter cartridge for cleaning oil contained in an oil sealed vacuum pump comprising:

• a cartridge housing, said cartridge housing being releasably mountable to the vacuum pump;
• a fluid path defined in said cartridge housing;
• and
• at least two types of filtering means having respectively different characteristics disposed in series in said cartridge housing along and forming a part of said fluid path,
• said filtering means including a mechanically acting filter stage and a chemically acting filter stage, said mechanically acting filter stage being disposed upstream of said chemically acting filter stage with respect to said fluid path, said chemically acting filter stage being composed of at least one of a chemical absorbent and adsorbent from the class consisting of fuller's earth and activated aluminum oxide in the form of a granulate having a grain size from 1 to 3 mm.