Abstract: A round filter element of a filter for a urea-water solution has a filter bellows with a filter medium that continuously extends circumferentially, relative to a filter element axis, around an element interior. An end body is fastened to an end face of the filter bellows and provided with a connecting section for fastening the round filter element to a housing cover of a filter housing of the filter. The end body has a central opening communicating with the element interior. The central opening has a central insertion section for receiving a flexible separation section of a volume compensation device of the filter and has an outer flow-through section enabling flow of the urea-water solution out of the filtration volume or into the filtration volume. The filter has a volume compensation device with a flexible separation section that separates a compensation volume from the filtration volume of the filter.

Abstract: A round filter element of a filter for a urea-water solution has a filter bellows with a filter medium that continuously extends circumferentially, relative to a filter element axis, around an element interior. An end body is fastened to an end face of the filter bellows and provided with a connecting section for fastening the round filter element to a housing cover of a filter housing of the filter. The end body has a central opening communicating with the element interior. The central opening has a central insertion section for receiving a flexible separation section of a volume compensation device of the filter and has an outer flow-through section enabling flow of the urea-water solution out of the filtration volume or into the filtration volume. The filter has a volume compensation device with a flexible separation section that separates a compensation volume from the filtration volume of the filter.

Abstract: A round filter element of a filter for a urea-water solution has a filter bellows with a filter medium that continuously extends circumferentially, relative to a filter element axis, around an element interior. An end body is fastened to an end face of the filter bellows and provided with a connecting section for fastening the round filter element to a housing cover of a filter housing of the filter. The end body has a central opening communicating with the element interior. The central opening has a central insertion section for receiving a flexible separation section of a volume compensation device of the filter and has an outer flow-through section enabling flow of the urea-water solution out of the filtration volume or into the filtration volume. The filter has a volume compensation device with a flexible separation section that separates a compensation volume from the filtration volume of the filter.

Abstract: A round filter element of a filter for a urea-water solution has a filter bellows with a filter medium that continuously extends circumferentially, relative to a filter element axis, around an element interior. An end body is fastened to an end face of the filter bellows and provided with a connecting section for fastening the round filter element to a housing cover of a filter housing of the filter. The end body has a central opening communicating with the element interior. The central opening has a central insertion section for receiving a flexible separation section of a volume compensation device of the filter and has an outer flow-through section enabling flow of the urea-water solution out of the filtration volume or into the filtration volume. The filter has a volume compensation device with a flexible separation section that separates a compensation volume from the filtration volume of the filter.

Abstract: A filter element has a filter material defining a raw side and a clean side of the filter element and to be flowed through by a medium to be filtered from the raw side to the clean side. A non-return element is disposed on the filter material. The non-return element allows a return flow of the filtered medium from the clean side back to the raw side and prevents a flow of the unfiltered medium from the raw side to the clean side. A filter and a filter system with such a filter element are disclosed. The filter system has a pump to supply medium to be filtered to the filter.

Abstract: A filter system for filtering fluids has a housing, an inlet, and an outlet. A filter element is arranged inside the housing. A cover closes the housing and provides access to the filter element inside the housing. A securing device prevents the housing from being closed by the cover when the filter element is missing. The filter element has at least one filter element guide path section. The housing or the cover has a rim area with at least one rim guide path section. The filter element guide path section and the rim guide path section supplement one another to a guide path. The securing device comprises at least one securing element arranged on the cover or the housing. The securing element is guided on the guide path when a closing movement is carried out for closing the housing by the cover.

Abstract: A filter element for filtering a fluid has a first filter medium arranged in annular shape and surrounding an interior. A second filter medium is provided, wherein the first filter medium and the second filter medium separate a clean side of the filter element from a raw side of the filter element. The first filter medium and the second filter medium are arranged such that a fluid to be filtered flows from the raw side of the filter element to the clean side of the filter element in parallel through the first filter medium and the second filter medium. The first filter medium is liquid-permeable and gas-impermeable and the second filter medium is liquid-impermeable and gas-permeable.

Abstract: A filter element has a filter material defining a raw side and a clean side of the filter element and to be flowed through by a medium to be filtered from the raw side to the clean side. A non-return element is disposed on the filter material. The non-return element allows a return flow of the filtered medium from the clean side back to the raw side and prevents a flow of the unfiltered medium from the raw side to the clean side. A filter and a filter system with such a filter element are disclosed. The filter system has a pump to supply medium to be filtered to the filter.

Abstract: A filter element for a motor vehicle for filtering a fluid has engaging and/or receiving elements that are designed to be connected to an adapter ring. The engaging and/or receiving elements have several hooks for engaging recesses of the adapter ring. and are arranged uniformly spaced in a circumferential direction about an central axis of the filter element. A filter set includes the filter element and the adapter ring, wherein the adapter ring deactivates a locking device of a first housing part that receives the filter element.

Abstract: A filter element for filtering a fluid has a first filter medium arranged in annular shape and surrounding an interior. A second filter medium is provided, wherein the first filter medium and the second filter medium separate a clean side of the filter element from a raw side of the filter element. The first filter medium and the second filter medium are arranged such that a fluid to be filtered flows from the raw side of the filter element to the clean side of the filter element in parallel through the first filter medium and the second filter medium. The first filter medium is liquid-permeable and gas-impermeable and the second filter medium is liquid-impermeable and gas-permeable.

Abstract: A filter system for filtering fluids has a housing, an inlet, and an outlet. A filter element is arranged inside the housing. A cover closes the housing and provides access to the filter element inside the housing. A securing device prevents the housing from being closed by the cover when the filter element is missing. The filter element has at least one filter element guide path section. The housing or the cover has a rim area with at least one rim guide path section. The filter element guide path section and the rim guide path section supplement one another to a guide path. The securing device comprises at least one securing element arranged on the cover or the housing. The securing element is guided on the guide path when a closing movement is carried out for closing the housing by the cover.

Abstract: A filter head for a pre-filtration filter for fuel has an electric pump received in a pump channel. A connecting channel connects the pump at a suction side with a clean side of the filter. An outlet channel connects the pump at a pressure side with a main filter for the pre-filtered fuel. The pump is alternatingly operated in at least two of the following operating modes: a feed or follow-up operation in which, before switching on or after switching off an ignition of the internal combustion engine, the pump supplies fuel to the outlet channel; a venting operation in which the pump pumps air out of the filter and/or a fuel line of the filter head; and a support operation in which, with switched-on ignition, the pump supplies fuel at a pressure suitable as input pressure for a high-pressure pump arranged downstream of the main filter.

Abstract: A filter element for filtering a fluid, in particular a urea solution, has an end disk provided with an opening. A filter medium is provided that closes off the opening and enables flow of the fluid between a clean side and a raw side of the filter element.

Abstract: A filter element for filtering a urea-water solution has a filter medium having an internal space. A supporting body is disposed in the internal space and has a hollow space which protrudes into the internal space. The hollow space is closed relative to a filtered side of the filter element and is open relative to an unfiltered side of the filter element. A compensation element is arranged in the hollow space.

Abstract: A filter system for filtering fluids has a housing, an inlet, and an outlet. A filter element is arranged inside the housing. A cover closes the housing and provides access to the filter element inside the housing. A securing device prevents the housing from being closed by the cover when the filter element is missing. The filter element has at least one filter element guide path section. The housing or the cover has a rim area with at least one rim guide path section. The filter element guide path section and the rim guide path section supplement one another to a guide path. The securing device comprises at least one securing element arranged on the cover or the housing. The securing element is guided on the guide path when a closing movement is carried out for closing the housing by the cover.

Abstract: A filter head for a screw-on filter element has a filter head body and a coupling section that is supported on the filter head body so as to be rotatable about a longitudinal axis of the filter head body. The coupling section has at least one first receptacle that receives a blocking element of a mounting device connected to a filter element. The blocking element is inserted in a direction of the longitudinal axis of the filter head into the first receptacle. The blocking element, when inserted in the first receptacle, blocks a rotation of the coupling section relative to the filter head body so that the filter element can be screw-connected to the filter head.

Abstract: A filter element for a motor vehicle for filtering a fluid has engaging and/or receiving elements that are designed to be connected to an adapter ring. The engaging and/or receiving elements have several hooks for engaging recesses of the adapter ring, and are arranged uniformly spaced in a circumferential direction about an central axis of the filter element. A filter set includes the filter element and the adapter ring, wherein the adapter ring deactivates a locking device of a first housing part that receives the filter element.

Abstract: A filter system for filtering fluids has a filter head and a filter cup with a rim area, wherein the filter cup is connected detachably by the rim area by a rotational and/or plug-in movement to the filter head. A filter element is exchangeably arranged in the filter cup. A sealing device with several sealing areas is provided that seals the filter head relative to the filter cup. The filter element has a connecting end disk arranged at an end face that is facing the rim area of the filter cup. On the connecting end disk at least two of the sealing areas of the sealing device are arranged so as to extend circumferentially in such a way that a first sealing area seals the connecting end disk relative to the filter head and a second sealing area seals the connecting end disk relative to the filter cup.

Abstract: A filter system for filtering fluids has a housing, an inlet, and an outlet. A filter element is arranged inside the housing. A cover closes the housing and provides access to the filter element inside the housing. A securing device prevents the housing from being closed by the cover when the filter element is missing. The filter element has at least one filter element guide path section. The housing or the cover has a rim area with at least one rim guide path section. The filter element guide path section and the rim guide path section supplement one another to a guide path. The securing device comprises at least one securing element arranged on the cover or the housing. The securing element is guided on the guide path when a closing movement is carried out for closing the housing by the cover.

Abstract: A filter system for filtering fluids has a filter head and a filter cup with a rim area, wherein the filter cup is connected detachably by the rim area by a rotational and/or plug-in movement to the filter head. A filter element is exchangeably arranged in the filter cup. A sealing device with several sealing areas is provided that seals the filter head relative to the filter cup. The filter element has a connecting end disk arranged at an end face that is facing the rim area of the filter cup. On the connecting end disk at least two of the sealing areas of the sealing device are arranged so as to extend circumferentially in such a way that a first sealing area seals the connecting end disk relative to the filter head and a second sealing area seals the connecting end disk relative to the filter cup.