Abstract: A multiple cartridge filter housing assembly for the high purity filtration of etching liquids, deionized water, slurries and other liquids used in the semiconductor, pharmaceutical and chemical industries. It comprises at least one upper and one lower cartridge within a bottom housing, a top housing and at least one extension housing. A vent tube in the top housing extending to the upper spacer ring in the extension housing generates a first air pocket between its lower end and the top of the housing assembly. The upper end of each cartridge is centered by a flow-through spacer ring. The lower end of each cartridge is sealed, against the pressure drop across the cartridge, and centered by an adapter ring. The adapter rings, except for the bottom one, have a downwardly extending tube with flow-through holes at its lower end such that secondary air pockets are generated above the holes and below the bottom surface of the adapter ring.