A device (1) is provided for ventilation and integrity testing of a filter unit (2) that can be supplied with pressure. The filter unit (2) has a filter element (9) arranged in a housing (6) between an inlet (7) and an outlet (8). The housing (6) can be ventilated by an air filter (3) connected to the housing interior (12). A filter valve (4) is arranged upstream of the air filter (3) facing the housing interior (12) and connects the air filter (3) to the housing interior (12). The air filter (3) can be connected on its side facing away from the housing interior (12) to a test line (14) for supplying pressure. An inlet valve (5) is arranged upstream of the inlet (7) and connects an inlet line (10) to the housing interior (12).

A water separator for water contained in fuel has a water separator housing with a separator element. A water collecting chamber is arranged in operation of the water separator below the separator element. A water collecting chamber through opening fluidically connects the water collecting chamber with the separator element. A drainage through opening has a first end which leads, for draining water from the water separator, out of the water separator. A second end is connected fluidically by an overflow valve to the water collecting chamber. The overflow valve has a float closing off a connection between drainage through opening and water collecting chamber when a water filling level has not reached the overflow valve. The float has an average density of 700 kg/m.sup.3 to 1,000 kg/m.sup.3 so that the float, when the water filling level is reached, opens the connection between water collecting chamber and drainage through opening.

Disclosed is a fuel filter (10) for fuel, in particular diesel fuel, of an internal combustion engine, in particular of a motor vehicle, and to a filter element of such a fuel filter. A housing (12) has at least one fuel inlet (26) for the fuel to be cleaned, at least one fuel outlet (18) for cleaned fuel, and at least one water outlet (30) for water which has been separated from the fuel. The filter element (36) is arranged in the housing (12), said filter element sealingly separating the fuel inlet (26) from the fuel outlet (18). The filter element (36) has a filter medium (38) which is designed as a hollow body and which can be permeated from the inside to the outside or from the outside to the inside in order to filter the fuel. The filter element (36) has a coalescing medium (58) designed as a hollow body for separating water contained in the fuel. The coalescing medium (58) is arranged downstream of the filter medium (38) in the flow path (78) of the fuel, around said filter medium, or in the interior (45) delimited by the filter medium. The coalescing medium (58) includes at least one regenerated-fiber coalescing system consisting of a coalescing material (60) which is suitable for coalescing water and which has at least 20 wt. % of regenerated fibers, preferably at least 50 wt. %.

A coalescing filter element provides an integrated filter element with a three stage design with a hydrophobic or hydrophilic coalescing layer. A coalescing filter element comprises: a) At least one particulate filtration layer; b) A coalescing layer promoting coalescing of water particles, wherein the coalescing layer is downstream of the at least one particulate filtration layer relative to the flow of fluid through the element; c) An annular coalescing space downstream of the coalescing layer; d) A sump in a lower portion of the filter element in fluid communication with the annular coalescing space; and e) A hydrophobic layer downstream of the annular coalescing space, wherein fluid being cleaned by the element flows through the hydrophobic layer. The coalescing layer may be a hydrophobic or a hydrophilic coalescing layer. A filter assembly will include the coalescing filter element of the present invention.

A filter device may include a filter housing and a filter element defining a longitudinal axis disposed in the filter housing. The filter element may be configured to be penetrated by a fluid flow in a radial direction from a raw end to a pure end of the filter element. A water separator may be disposed at the pure end of the filter element and arranged axially spaced from the same. The water separator may have a hydrophobic and annular diaphragm extending in an axial direction of the filter element configured to be penetrated by the fluid flow from a raw end of the water separator in a radially outward to a radially inward direction with respect to the longitudinal axis to separate water from the fluid flow.

A filter assembly comprises a filter housing defining an internal volume, a filter element positioned within the internal volume, and a gasket retainer. An outer edge of the gasket retainer is coupled to a top end of the filter housing, and an inner rim thereof forms a gasket retainer ledge. The filter assembly further comprises a retainer loop comprising a retainer loop main body. A plurality of retainer arms extend axially from the retainer loop main body towards the gasket retainer. Each of the plurality of retainer arms comprise a retainer arm ledge extending radially towards the retainer loop main body and snap-fit to the gasket retainer ledge. A retainer loop sidewall extends from the main body away from the gasket retainer. An outer surface of the retainer loop sidewall defines a curvature. A sealing member is removably positioned around the outer surface of the retainer loop sidewall.

A fuel supply device includes a filter device, a pump, a suction pipe, and a bubble removing device. The filter device includes a first filter that filters a fuel, a filter chamber surrounded by the first filter, and a filter opening that is in fluid communication with the filter chamber. The pump has a pump suction port for drawing the fuel from the filter chamber. The suction pipe fluidly connects the filter opening to the pump suction port. The bubble removing device is disposed in at least one of the filter device and the suction pipe. The bubble removing device includes a valve device that is configured to discharge a bubble contained in the fuel to the internal space of the fuel tank, and a foreign matter regulator that is disposed between the valve device and the internal space and that regulates or prevents a foreign matter contained in the fuel from flowing into the fuel supply device.

The liquid recovery filter includes several embodiments, each of which provides for the recovery of liquid otherwise trapped within the filter housing and element. Each embodiment includes a series of vents, purge ports, and passages that communicate fluidly with the filter housing and filter core. Certain vents and purge ports are initially opened following filtration operations to allow pressurized gas to flow into the housing, thereby forcing residual unfiltered liquid through the filter. When this has been accomplished, another vent is opened to the filter core to allow filtered liquid to flow from the downstream or outlet passage from the filter core. Some embodiments have the filter outlet located above the filter, and include a downstream drain port extending from the filter core. The downstream drain port provides for the recovery of filtered liquid when the vent or purge port is opened in these embodiments.

Various example embodiments relate to an automatic drain system for use with a fluid water separator. The automatic drain system includes a liquid-in-fuel sensor configured to detect a liquid level in a water sump. A pump includes an inlet in fluid communication with the water sump and an outlet in fluid communication with the inlet. The pump has an active state and an inactive state. The active state causes the pump to draw liquid in from the inlet and direct liquid toward the outlet. A battery is configured to power the pump. A circuit board is operably connected to the pump and battery. The circuit board includes at least one circuit having a first state and a second state. The first state prevents power flow from the battery to the pump. The second state facilitates power flow from the battery to the pump, transitioning the pump from inactive to active.

A filter element for a fuel filter has first and second end plates and a particle filter medium arranged between the first and second end plates. A bayonet protrusion on the first end plate is designed to engage a bayonet receptacle of the filter housing by rotation of the filter element about a filter element longitudinal axis. An internal sealing element on the second end plate is designed to separate a raw side from a water collecting chamber of the fuel filter. The filter housing has a filter housing body and a cover screwed onto the filter housing body. The filter housing has a bayonet receptacle arranged on its inner side. By rotating the filter element about a filter element longitudinal axis of the filter element, the bayonet protrusion engages the bayonet receptacle of the filter housing when the cover is unscrewed from the filter housing body.