Abstract: An invertable filter centrifuge having a housing defining a centrifuge chamber with a perforated drum mounted in said chamber on the front end of a hollow shaft which is rotatably mounted at the front end by a front bearing assembly and slideably mounted on a central shaft having a base plate mounted on a front end thereof with a filter cloth which is disposed with one end attached to the drum and the other end attrached to said base plate and normally disposed within said drum with double acting piston means for displacing the drum axially for inverting the filter cloth, a quantity of lubricating fluid for contacting bearings in the bearing assembly with, and a nitrogen gas pressurized seal disposed between the bearing assembly and the centrifuge chamber for inhibiting the passage of contaminants therebetween.