Abstract: An integrity testing method for a porous medium in a housing having an interior separated by the medium into upstream and downstream portions, an inlet and an outlet communicating, respectively, with the upstream and downstream portions, the outlet connected to a closeable conduit, comprises filling the downstream portion and conduit with liquid, draining the upstream portion and filling it with gas while retaining liquid in the downstream portion, connecting a gas-filled testing volume to the downstream portion, maintaining gas pressure of a predetermined testing differential pressure in the upstream portion, the differential pressure being lower than a predefined bubble point of the medium, determining the pressure in the testing volume, the testing volume selected such that, when a medium is tested having a bubble point corresponding to the predefined bubble point, a pressure increase within the testing volume of about 100 mbar or more is obtained within 10 minutes.

Abstract: The invention relates to a filter element comprising one or more fluid-pervious layers of a fluid-pervious sheet material having first and second surfaces in a substantially parallel arrangement, a fluid-impervious layer arranged in fluid tight contact with at least one of said first and second surfaces of said layer(s) of fluid-pervious sheet material to substantially fully cover the first and/or second surfaces thereof, one or more first and second edge portions, said first and second edge portions being arranged at a predefined distance and separated from one another by a predefined area of the fluid-pervious sheet material, a fluid flow path limited to and extending essentially parallel to the first and second surfaces from the first edge portion(s) to the second edge portion(s) within each of said layers of fluid-pervious sheet material, said first and second edge portions providing a fluid intake and a fluid drainage at the upstream and downstream ends of said fluid flow path, respectively.

Abstract: An integrity testing method for a porous medium in a housing having an interior separated by the medium into upstream and downstream portions, an inlet and an outlet communicating, respectively, with the upstream and downstream portions, the outlet connected to a closeable conduit, comprises filling the downstream portion and conduit with liquid, draining the upstream portion and filling it with gas while retaining liquid in the downstream portion, connecting a gas-filled testing volume to the downstream portion, maintaining gas pressure of a predetermined testing differential pressure in the upstream portion, the differential pressure being lower than a predefined bubble point of the medium, determining the pressure in the testing volume, the testing volume selected such that, when a medium is tested having a bubble point corresponding to the predefined bubble point, a pressure increase within the testing volume of about 100 mbar or more is obtained within 10 minutes.

Abstract: The invention relates to a filter element comprising one or more fluid-pervious layers of a fluid-pervious sheet material having first and second surfaces in a substantially parallel arrangement, a fluid-impervious layer arranged in fluid tight contact with at least one of said first and second surfaces of said layer(s) of fluid-pervious sheet material to substantially fully cover the first and/or second surfaces thereof, one or more first and second edge portions, said first and second edge portions being arranged at a predefined distance and separated from one another by a predefined area of the fluid-pervious sheet material, a fluid flow path limited to and extending essentially parallel to the first and second surfaces from the first edge portion(s) to the second edge portion(s) within each of said layers of fluid-pervious sheet material, said first and second edge portions providing a fluid intake and a fluid drainage at the upstream and downstream ends of said fluid flow path, respectively.