Patent ID: 8733555

Claim:
A filter cartridge comprising: a housing including first and second housing sections generally symmetrically disposed about a longitudinal axis and joined at a circumferential shoulder to define an interior volume extending between first and second ends of said housing, said first housing section including a grommet support clip projecting into said interior volume, said grommet support clip defining a fluid flow opening coaxial with said longitudinal axis, said first housing section including a generally cylindrical first side wall with a first side wall first end adjacent said circumferential shoulder, said first side wall having a first diameter and said first housing section including a first transition portion extending radially inwardly from a first side wall second end to said grommet support clip, said first transition portion defined by a radius rotated about a point within said interior volume, rotation of said radius subtending an obtuse angle; said second housing section including a generally cylindrical second side wall having a second diameter larger than said first diameter, said second side wall extending between said circumferential shoulder and a second transition portion at said housing second end, said second transition portion extending radially inwardly from said second side wall to a drain opening defined at said housing second end; a grommet radially surrounded by said grommet support clip, said grommet extending from an upper shoulder outside said interior space to a lower shoulder projecting into said interior space; a drain valve situated in said drain opening and moveable between a first position where said drain valve closes said drain opening and a second position in which said drain valve permits fluid communication with said interior space through said drain opening; and filter media supported within said interior space for filtering fluid passing through said filter cartridge, wherein said housing is imperforate other than said fluid flow opening and said drain opening and configured to contain a fluid to be filtered.