A filter that includes: a filter part having a plurality of through-holes; a frame portion on an outer periphery of the filter part; and a tab that protrudes from an outer periphery of the frame portion, the tab having a plurality of protrusions.

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 system may include a housing, a filter element, and a separate positioning mechanism. The housing may include an opening, a function carrier, a drain opening, and a radially protruding contour. The filter element may include a first end disc, a second end disk, and a filter material disposed between the first end disk and the second end disk. The first end disk may include at least one of a radially projecting contour and an inwardly projecting recess. The second end disk may include a central opening and an eccentrically projecting locking pin. The central opening may be adapted to interact with the function carrier. The positioning mechanism may have a body with a first recess and at least one second recess, which may be configured to facilitate positioning and aligning the filter element in the housing such that the locking pin engages in the drain opening.

Provided is a filtration device that can increase a filtration treatment amount by suppressing clogging of a filtration filter. A filtration device according to the present invention includes: a filtration filter that includes a filter that filters a filtration target contained in a fluid, and a frame that holds the filter; a support structure that holds the frame such that the filter is bent; and a fluid supplying unit that supplies the fluid with the filter being in a bent state.