Abstract: A filter support sleeve for use with a filter element to provide structural support for the filter element. The support sleeve encompasses the filter element and includes a metal strip wound in helical turns joined by a continuous spiral weld to form a hollow cylinder. The metal strip has substantially square perforation for passage of fluid flow through the support sleeve oriented such that when the metal strip is helically wound, a line parallel to each side of the square-shaped perforation is skew with the axial axis of the support sleeve. The support sleeve present an open structure while protecting the filter element from forces generated by the fluid flow during normal use or back flow during cleaning. When used with a pleated filter element, the support sleeve will not obstruct the entire length of the pleats.

Abstract: An improved leaf disc filter segment having a central drainage plate and a hub defining a central cavity. The drainage plate has radial beams and diametrical rings. The diametrical rings extend generally one-half of the height of the radial beams and are configured to alternately extend from either an upper surface or a lower surface of the radial beams such that the diametrical rings are alternately positioned in either an upper portion or lower portion of the drainage plate. The radial beams and diametrical rings define radial flow paths through the drainage plate to the central cavity through openings in the hub. The radial beams and diametrical rings are configured to provide trapezoidal openings of generally constant area to the flow channels of the drainage plate.