Patent ID: 7311208

Claim:
An environmentally friendly filter cartridge constructed to fit in a filter housing, the filter cartridge comprising: a cylindrical filter element having an internal bore of a size capable of sliding over a centertube in a corresponding housing; a first endcap coupled to a first end of the filter element, the first endcap having an open center sized to permit the centertube to pass therethrough, a first gasket being coupled to the first endcap; a second endcap coupled to a second end of the filter element, the second endcap having a closed center, a second gasket being coupled to the second endcap; and a pressure equalizing aperture at a circumferential portion in the second endcap for equalizing the pressure differential across the second endcap during filter operation, and a plurality of support shoulders formed on the circumferential portion of the second endcap for assisting in centering the cartridge and resisting crushing forces applied to the second endcap during filtration operation of the filter cartridge.