Patent ID: 7296689

Claim:
A filter cartridge for aqueous liquid media at risk for freezing employed in fuel cell operated vehicles or in connection with internal combustion engines, the filter cartridge comprising: a housing; a filter lid connected to the housing for closing the housing; a filter insert inserted into the housing and comprising at least one filter element and terminal parts wherein the at least one filter element is positioned between and secured by the terminal parts; at least one reinforcement part that is a filler member inserted into and penetrating an interior of the at least one filter element and connected to the terminal parts, wherein between an exterior surface of the at least one reinforcement part and an inner circumference of the at least one filter element an annular chamber is formed, wherein a liquid medium passing radially inward through the at least one filter element flows axially through the annular chamber out of the filter cartridge; wherein a volume of the annular chamber of the at least one filter element is so small that aqueous liquid medium contained in the annular chamber causes no impairment of filter properties when freezing; wherein the reinforcement part comprises a profiled section configured to receive torque and axial forces; wherein the profiled section is a narrow end of the reinforcement part; wherein the reinforcement part has an end section adjoining the narrow end; wherein the the end section and the narrow end have approximately axially extending depressions or flattened portions providing a flow cross-section for the liquid.