Abstract: A filter cartridge assembly includes a filter cartridge having a generally cylindrical filter medium which defines a cylindrically shaped core space, and a pair of end caps fixed to opposite ends of the filter medium. Most preferably, the filter cartridge is "coreless" in that it is not provided with an integral support core structure. At least one of the end caps (e.g., the proximal end cap) is annular and has an interior cylindrical surface defining an interior space in alignment with the core space. A truncated generally conically shaped seal skirt is operatively associated with the annular end caps. The filter cartridge is sleeved over reusable support core structure which includes a base having a truncated conically shaped seal skirt, and a tubular perforated rigid core element fixed at one end to the base. The annular end-cap and the base of the support core structure are removably mechanically coupled to one another, most preferably by being threadably interconnected.