A cylindrical filter element having a central longitudinal axis and filter media including a plurality of radially extending pleats arranged in a pattern that repeats around the central longitudinal axis. Each of the pleats comprises an inner pleat tip, wherein the inner pleat tips of each pattern define an open area that extends along a height of the filter element, and wherein each pattern of pleats comprises a first series of intermediate pleats that descends in length from a major pleat to a minor pleat and a second series of intermediate pleats that ascends in length from the minor pleat to a major pleat of an adjacent pattern of pleats.

A cylindrical filter element having a central longitudinal axis and filter media including a plurality of radially extending pleats arranged in a pattern that repeats around the central longitudinal axis. Each of the pleats comprises an inner pleat tip, wherein the inner pleat tips of each pattern define an open area that extends along a height of the filter element, and wherein each pattern of pleats comprises a first series of intermediate pleats that descends in length from a major pleat to a minor pleat and a second series of intermediate pleats that ascends in length from the minor pleat to a major pleat of an adjacent pattern of pleats.

A cylindrical filter element including a central longitudinal axis extending along a height of the filter element, a core element extending along at least a portion of the height of the filter element and having a convex curved central portion extending from a first end to a second end to define a width of the core element, wherein the convex curved central portion has a maximum height through the central longitudinal axis that is larger than a height of at least one of the first and second ends, and filter material including a plurality of pleats extending radially from an outer periphery of the core element, wherein an outer cylindrical periphery of the filter material is defined by an outer pleat tip of each of the plurality of radially extending pleats, and wherein an inner pleat tip of each radially extending pleat is adjacent to the core element.

A filter element (1) has an inner body (12) and an outer body (11). One casing body (12) has a cross section deviating from circularity. Body contact surfaces (20, 21) face one another for the contact of essentially all filter folds (18a-18f, 18.sub.I-18.sub.III) of a pleated filter web (10). The filter folds (18a-18f, 18.sub.I-18.sub.III), in terms of fold height (h), are divided into individual groups (I, II) each having several filter folds (18.sub.I-18.sub.II) of a common fold height (h.sub.max, h.sub.min) alongside one another in sections. Between two adjacent filter folds (18a-18f, 18.sub.I-18.sub.III) of different groups (I, II) filter folds are arranged (18b-18e; 18m) of at least one third group (III). The filter folds (18b-18e, 18m) of the third group (III), in the manner of step formation, have a common fold height (h.sub.D) different from the respective fold height (h.sub.max, h.sub.min) of the filter folds (18.sub.I-18.sub.II) of the two adjacent neighboring groups (I, II), and/or, in the manner of curve formation, have different fold heights, establishing a transition between the fold heights (h.sub.max, h.sub.min) of the two adjacent groups (I, II).

A filter element (1) has an inner body (12) and an outer body (11). One casing body (12) has a cross section deviating from circularity. Body contact surfaces (20, 21) face one another for the contact of essentially all filter folds (18a-18f, 18.sub.I-18.sub.III) of a pleated filter web (10). The filter folds (18a-18f, 18.sub.I-18.sub.III), in terms of fold height (h), are divided into individual groups (I, II) each having several filter folds (18.sub.I-18.sub.II) of a common fold height (h.sub.max, h.sub.min) alongside one another in sections. Between two adjacent filter folds (18a-18f, 18.sub.I-18.sub.III) of different groups (I, II) filter folds are arranged (18b-18e; 18m) of at least one third group (III). The filter folds (18b-18e, 18m) of the third group (III), in the manner of step formation, have a common fold height (h.sub.D) different from the respective fold height (h.sub.max, h.sub.min) of the filter folds (18.sub.I-18.sub.II) of the two adjacent neighboring groups (I, II), and/or, in the manner of curve formation, have different fold heights, establishing a transition between the fold heights (h.sub.max, h.sub.min) of the two adjacent groups (I, II).

A filter cartridge includes an open-ended housing and filter element supported in the housing and defining an annular region between a periphery of the filter element and a side housing wall. A water collection region is between an end of the filter element and a lower-housing wall. The filter element includes pleated media surrounding an axially-extending central area, and pleats of different heights round the central area. An end plate is bonded to the filter element to prevent fluid flow through the pleats' upper ends. One passage is through a plate opening into the central area. Another passage is between the end plate and peripheral region. The filter element has freely-supported lower ends. A seal between the lower periphery of the filter element and the housing prevents fluid bypass of the filter element. Fluid passes through the pleats, and water coalesces on the media and drains into the collection region.

A device for treating fluid, in particular a filter device, has first and second tubular elements (12), (14) forming an element assembly (10). One element (14) is accommodated in the other element (12) forming a flow chamber (33) between the two elements (12, 14), with a first element (12) arranged in the direction of the inflow side (29) of a fluid to be treated and a second element (14) arranged in the direction of the outflow side (31) of the treated fluid in the element assembly (10). During the fluid treatment, the flow is routed through both elements (12, 14) in succession from the direction of the inflow side (29) towards the outflow side (31). In a joint viewing direction (P), the first element (12) facing the inflow side (29) at least partially has a uniform or non-uniform contour and the second element (14) facing the outflow side (31) at least partially has a non-uniform or uniform contour.

A scaling tool for replicating filtration characteristics of a large-scale filtration device, the scaling tool comprising a housing having a fluid inlet and a fluid outlet, and a filter receiving region in fluid communication with the fluid inlet and the fluid outlet and configured to contain a membrane comprising one or more pleats, the filter receiving region being defined by a rigid wall framework configured to hold the one or more pleats of the membrane and compress the pleats in an amount effective to replicate the filtration performance of the large-scale filtration device. Also disclosed is a methodology for configuring a filter receiving region in a scaling tool.

A liquid filter has inflow and outflow faces connected by a throughflow path. A one-piece filter body of a folded filter medium bellows is provided. Each fold has first and second fold sheets joined at a fold edge and two fold end faces. The filter body is installed into a pre-defined installation space of a vehicle, the installation space defined and delimited by a base free-form surface, a cover free-form surface, and a side free-form surface. The fold edge heights of the folds are adapted to a contour of cover free-form surface; base free-form surface; or cover and base free-form surfaces. First folds with first fold edge height and second folds with second fold edge height that differ from each other are provided. Third folds have fold end faces adapted to a contour of the side free-form surface facing these fold end faces. An envelope around all fold end faces and rim folds deviates from a rectangle.

A filter element (1), with a preferably multilayer structure of a filter medium (3), in pleated form has filter pleats (5, 7) of different pleat heights (h1, h2). The filter pleats (7) with a first pleat height (h1) oppose the filter pleats (5) lower second pleat height (h2). The filter element has a throughflow direction for fluid to be cleaned away from a dirty side to a clean side (R). The transitions arranged adjacent to the inner side all conclude along a fictitious circular cylinder (9), which penetrates the filter medium (3) coaxially to its longitudinal axis (LA).