Filter with over-laid pleats in intimate contact

A filter for separating one or more substances from a fluid flowing therethrough, the filter comprising:

• a pleated filter element including an outer diameter (D), an inner diameter (d), a longitudinal axis, first and second end surfaces, and a plurality of longitudinal pleats, wherein the pleated filter element comprises a pleated composite having a thickness (t) and including an upstream drainage layer, a downstream drainage layer, and a filter medium disposed between the upstream and downstream drainage layers, the upstream drainage layer having an edgewise flow resistance which provides a lower pressure drop in the upstream drainage layer than the pressure drop across the filter medium, thereby providing an even distribution of fluid along an upstream surface of the filter medium, wherein each of the pleats has a curved configuration and includes a crown, a root, and a pair of legs and each of the legs has a first surface and a second surface, the legs of each pleat being joined to one another at the crown and joined to a leg of an adjacent pleat at the root and the pleats being in a laid-over state in which the first surface of one leg of one pleat is in intimate contact with the first surface of an adjoining leg of said one pleat and the second surface of said one leg is in intimate contact with the second surface of an adjoining leg of an adjacent pleat over substantially the entire height of each leg and over a continuous region extending for at least approximately 95% of the longitudinal length of the pleated filter element, and wherein the height of each pleat is greater than (D-D)/2 and is no greater than (D.sup.2 -d.sup.2)/4(d+2 t), and
• first and second end elements sealingly arranged with the first and second ends, respectively, of the pleated filter element, at least one of the end elements comprising an open end element.