Abstract: A filter arrangement includes a filter cartridge having a first filter element and a second filter element. The first filter element includes a first tubular section of filter media extending between first and second end caps and defining a first open filter interior. The second filter element includes a second tubular section of filter media operably oriented in the first open filter interior. The second tubular section of filter media extends between third and fourth end caps and defines a second open filter interior. The first end cap defines an inner container and an outer container circumscribing the inner container. The outer container is secured to the first tubular section of filter media. The inner container has an end wall axially spaced from the outer container. The third end cap has a media end secured to the second tubular section of filter media and a tubular wall axially extending from the media end. The tubular wall is circumscribed by the inner container of the first end cap.

Abstract: A filter cartridge 38 includes a first endcap 41 defining a first open aperture and having at least first and second protrusions extending from a wall along the aperture and into the first open aperture. The first protrusion is spaced from the second protrusion in both a vertical direction and a circumferential direction. The filter cartridge also includes filter media 44 and a second endcap 42. The filter cartridge is mountable in a filter bowl 36 having an inner liner assembly, and the bowl and the inner liner assembly is connectable to a filter head to form a filter system.

Abstract: A composite membrane including an ion exchange polymer and a support of expanded polytetrafluoroethylene polymer having a porous microstructure of polymeric fibrils, said expanded polytetrafluoroethylene polymer being at least about 85% crystalline.