Patent ID: 9421489
Filing Date: 2016-08-23
CPC Classification: B01D,F01M

Claim Text:
1. A filter including: a housing circumscribing a central axis, the housing having an inlet at a lower end and an outlet at an upper end; a filter element disposed within an upper portion of the housing, the filter element having an interior surface defining an inner upper chamber and an exterior surface defining with an interior surface of the housing an outer upper chamber; a standpipe forming a passageway communicating at an upper end to the outlet and at a lower end to a lower chamber in the housing below the inner upper chamber, the lower end of the standpipe extending through the inner upper chamber to a point no higher than a lower exposed surface of the filter element; and a check valve that permits flow from the lower chamber to the inlet and blocks flow from the inlet to the lower chamber.