Abstract: A filter element is formed by spirally winding at least two layers of filter material about a central, perforate supporting core. The layers include a relatively fine porous filter material and a relatively coarse porous filter material. The layers may be formed from blankets of material, or one or both layers may be pleated. The fine filter material extends beyond the edge of the coarse filter material to overlie and close the longitudinal ends of the layers of the coarse material. Fluid to be filtered passes radially through the element until it encounters a clogged or plugged area. The fluid will then take a circumferential spiral route until it again finds an open area of the filter and can pass radially toward the core.