Abstract: A filter appliance may include a ring filter element arranged upright in a filter having an upper end disc and a lower end disc. A component may be arranged on the lower end disc and may include at least one of a water collection pot, a projecting nipple-shaped pin and at least one key profile. A function element may be configured to be inserted in a filter housing pot of the filter appliance, the function element including a channel configured to receive the component. A lock profile may be provided on the function element, wherein the lock profile corresponds to the at least one key profile of the lower disk. The filter appliance is may be operational provided the pin engages the channel and the key profile engages in the lock profile.

Abstract: A filter device may include a ring filter element arranged in a filter housing in an upright manner. The ring filter element may have an upper end disc and a lower end disc. A dirt pot may have a water separator arranged therein and be provided on the lower end disc. The dirt pot may also have a protruding pin. A channel may be configured to receive the pin and be provided on at least one of a filter housing pot and a functional element. The filter device may be operational when the pin engages into the channel.

Abstract: A module insert includes at least one water level sensor, at least one valve, at least one flow channel for water, and at least one reservoir with a sorbent mechanism. The sorbent mechanism is configured to absorb impurities from the separated water and is disposed in the reservoir. The sorbent mechanism is further configured to extend a dwell time of the separated water in the module insert.

Abstract: A filter device includes a filter housing and a filter element disposed in the filter housing. The filter element is configured to be penetrated by a fuel flow in a radial direction from a raw end to a pure end of the filter element. A water separator is disposed at the pure end of the filter element and extends in an axial direction of the filter element. The water separator has a hydrophobic and annular diaphragm through which fuel can flow from a radially outward to a radially inward direction.

Abstract: A module insert includes at least one water level sensor, at least one valve and at least one flow channel for the water. The module insert has at least one container having sorbent mechanism for collecting contaminants from the separated water. A pressure-resistant housing is configured to protect an interior of the module insert from the pressure of the fuel.

Abstract: A filter device having a liquid inlet, a liquid outlet, a filter housing, and at least one filter element. At least one water collection chamber is configured to collect water separated out of the fuel. A mechanism for suppressing biological activity is disposed in at least the water collection chamber.

Abstract: A fuel filter having a filter housing including at least one filter element. A water collection chamber configured to collect water separated out of the fuel. An active carbon filter is disposed downstream of the water collection chamber and a water-soluble dividing device is disposed between the water collection chamber and the active carbon filter and is impermeable or insoluble to fuel.

Abstract: A fuel filter includes a filter element disposed in a filter housing. The filter element is penetrated by fuel flowing in a radial direction from a raw end to a pure end. The fuel filter has a first water separator and a smooth-flow second water separator disposed in series with and connected to the first water separator. Fuel is discharged from the second water separator by a pressure difference generated in the fuel filter.

Abstract: A liquid-conducting hollow cross-section liquid discharge line, including a liquid having temperature-dependent volume changes, wherein the liquid solidifies under certain temperature conditions, and wherein the hollow cross-section includes at least one displacement element, the displacement element reduces the free cross-section available for a liquid; and wherein the discharge line is in a fuel filter system.

Abstract: The present invention relates to a fuel filter (1) for a fuel supply system of an internal combustion engine, in particular in a motor vehicle, comprising a filter housing (2) and a filter element (3). The filter housing (2) has an untreated-side inlet (4), a treated-side outlet (5) and an untreated-side return line (6). The filter element (3) is arranged in the filter housing (2) and, therein, separates an untreated space (13), which communicates with the inlet (4) and with the return line (6), from a treated space which communicates with the outlet (5). Additionally provided is a closure element (20) which, in the operationally ready state of the fuel filter (1), closes off the return line (6).