Abstract: A fluid filtration apparatus is disclosed particularly usable with a perforate tubular fluid conduit as normally used for filtration of cleaning fluids and the like wherein the filtration apparatus includes a plurality of filter elements being generally cylindrical and defining a central channel therethrough to be adapted to receive the fluid conduit extending therebetween. Also included are a plurality of gasket assemblies positionable between adjacent filter elements to minimize passage of cleaning fluid therethrough to facilitate cleansing of the fluid. An outer retainer is utilized for compressing the individual filter element against the filter gaskets in such a manner as to provide a continuous filtration media along the entire length of the tubular fluid conduit and to prevent outlets for fluid emanating therefrom without passage through filtration media.

Abstract: A filter cartridge of the type made from a sheet of filter paper pleated as an accordion on a cylindrical surface. It is produced by pinching pairs of contiguous pleats at various levels in order to make on the outer surface of the cartridge a plurality of honeycombs. The invention results in substantially prolonged life of the filter cartridges, which have applications in a variety of uses, including regeneration of solvents of washing baths for dry cleaning machines, filtration of air for internal combustion engines and water filtration.