A filter element for fluids, in particular for hydraulic fluid, has a foldable filter casing (10) with at least one filter layer (18, 20, 22, 24) extending between two end caps (26, 32). To vary in regions the thickness of the filter casing (10), the height (h.sub.1) of each filter fold (12, 44) increases from one end cap (26) to the other end cap (32). Alternatively, with the filter fold height (h.sub.1) being maintained, the outer diameter (40) of the filter casing (10) varies in the direction of one of the end caps (26, 32).

An end cap for a fuel filter includes a metal body with a first surface opposite a second surface. A hole extends through the first surface and the second surface of the body. A metal spring is connected to the first surface of the metal body and extends at least partially over the hole.

A co-precipitation reactor with a continuous filtering system mounted, wherein the co-precipitation reactor includes a main body accommodating a reactant for reaction therein, an input unit inputting the reactant into the main body, and a filter unit installed in the main body to filter a precursor of the precursor generated by reacting with the reactant in the main body and a reaction solution.

A method for manufacturing a filter includes providing a computer-readable three-dimensional model of the filter, the three-dimensional model being configured to be converted into a plurality of slices that each define a cross-sectional layer of the filter, and successively forming each layer of the filter by additive manufacturing.

A device for treating fluid, in particular a filter device, having at least one first (12) and one second tubular element (14) forming an element assembly (10) with each other, wherein the one element (14) is accommodated in the other element (12) forming a flow chamber (33) between the two elements (12, 14) such that a first element (12) is arranged in the direction of the inflow side (29) of a fluid to be treated and a second element (14) is arranged in the direction of the outflow side (31) of the treated fluid in the element assembly (10), and wherein 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), is characterized in that, in relation to a joint viewing direction (P), the first element (12) facing the inflow side (29) at least partially has a uniform or non-uniform con tour and the second element (14) facing the outflow side (31) at least partially has a non-uniform or uniform contour.

A filter cartridge has media construction, a housing, and a first end construction. The first end constructions includes an outer radial wall with circumferentially spaced connecting sections; each connecting section having a plurality of helical profiles extending at a helix angle. The filter cartridge is removably attached to a filter head, which has mating connecting segments. A bowl cartridge assembly is also provided including connecting sections with a plurality of helical profiles.

An adaptor device for retrofitting in a filter housing is disclosed. The adaptor device allows the filter to be retrofitted with a plurality of filter elements, thereby improving its filtering efficiency.

A filter element has a preferably multilayer structure of a pleated filter medium (3) with a plurality of individual filter pleats (5, 7). Due to an alternating sequence of filter pleats (5) with a first pleat height (h1) and filter pleats (7) with a second pleat height (h2), more effective filter surfaces are available than with filter pleats with a uniform pleat height. Upon throughflow by a fluid to be filtered, a lower surface load for the filter medium (30 and lower passage speed of the fluid are present during filtration. A static loading of the filter medium (3) during operation of the filter is then reduced. A hydraulic circuit has such a filter element (1).

A method for manufacturing a filter includes providing a computer-readable three-dimensional model of the filter, the three-dimensional model being configured to be converted into a plurality of slices that each define a cross-sectional layer of the filter, and successively forming each layer of the filter by additive manufacturing.

A filter system (200) includes a housing (210) in which a replaceable filter element (100) is arranged between a pre-filtration side (202) and a post-filtration side (204). The filter element (100) has an element-fixed central tube (150), wherein a closure element (10) is provided on a housing side, the closure element (10) opening a post-filtration-side fluid outlet (250) when the filter element (100) has been inserted, and blocking the post-filtration-side fluid outlet (250) when the filter element (100) has been removed. The filter element (100) has an actuating element (160) for the closure element (10).