US Patent 6846412 Combination filter assembly

A combination filter assembly having a plurality of filter sieves positioned in parallel one after the other in the direction of flow. The filter sieves are stretched and mounted in housing elements to form filter elements. The housing elements are in contact with each other by means of top and bottom bearing faces, and are maintained in a stack. The filter elements have a cylindrical shape with annular bearing faces, wherein one bearing face includes a centering male coupling and sealing formation, and the other bearing face includes a corresponding centering female coupling and sealing formation.