Patent ID: 7662284

Claim:
A filter assembly including: (a) a filter head arrangement comprising: (i) a cover member; and, (ii) a plate arrangement secured in the cover member and defining: an unfiltered liquid flow channel; and, a central filtered liquid flow channel; (A) the central, filtered liquid flow channel including a flow exit aperture; (iii) an anti-drain back valve arrangement including a valve assembly having: a valve member; a biasing member; and, having a first, closed, orientation and a second, open, orientation; (A) the first closed orientation being an orientation in which the valve member is biased to close the exit aperture of the filtered liquid flow channel by the biasing member; and, (B) the second, open, orientation being an orientation which results from filtered liquid flow passage, in use, biasing the valve member away from the exit aperture of the filtered liquid flow channel; (b) a filter bowl releasably mounted on the filter head; and (c) a filter cartridge positioned within a filter bowl; the filter cartridge comprising: (i) a region of filter media defining a central, open, volume, (A) the region of filter media having first and second ends; (ii) a first end cap secured to the first end of the region of filter media; (iii) the filter cartridge including an axial stem thereon defining a central liquid flow conduit therethrough, in liquid flow communication with the central, open, volume defined by the filter media; (A) the axial stem including a portion projecting away from the filter media; (B) the axial stem including an outer, annular, seal arrangement thereon; and (C) an end of the axial stem remote from the filter media comprising an anti-drain back valve arrangement opening tip allowing the anti-drain back valve arrangement to be in the second, open, orientation; and, (iv) a second end cap secured to the second end of the region of filter media; and (d) the anti-drain back valve arrangement being configured to bias to the first, closed, orientation when the bowl is removed from the valve head and the filter cartridge axial stem is separated from the anti-drain back valve arrangement.