Fluid filter with pressure relief valve
View Patent ↗A fluid filter assembly having a relief valve for visually indicating when a filter element may be replaced. The fluid filter assembly of the present invention provides a vertical, transparent housing having a fluid inlet for communicating a fluid into the housing and a fluid outlet for communicating fluid downstream of the housing. A filter element is disposed within the housing between the fluid inlet and the fluid outlet for filtering the fluid.
1. A fluid filter assembly for filtering fluid, comprising:
a vertical housing having a fluid inlet for communicating said fluid into said housing and a fluid outlet for communicating said fluid downstream of said housing wherein said housing has a transparent outer cover for viewing the level of fluid in said housing;
a filter element disposed within said housing and in fluid communication between said fluid inlet and said fluid outlet for filtering said fluid, and said filter element having a top and a bottom wherein said fluid flows from said bottom to said top of said filter element and wherein both said top and said bottom are positioned above both said fluid inlet and said fluid outlet;
a divider connected to said top of said filter element and extending downward between an outer wall of said housing and an unfiltered side of said filter element toward a bottom of said housing to adjacent said filter element bottom to divide said housing into an outer region and an inner region, wherein said outer and inner regions are in communication at a lower portion of said housing;
a relief valve in communication with said outer portion of said housing such that captured air in said outer portion of said housing forces said fluid in said inner portion to maintain a higher level than said fluid in said outer portion until said predetermined pressure level across said filter element is reached thereby forcing said relief valve to open and allow air/vapor to pass through said relief valve thereby allowing the level of said fluid in said outer portion to rise and provide a visual indicator as to the needed replacement of said filter element;
said top of said filter element having a recessed cup portion, wherein said recessed cup portion has at least one aperture extending therethrough to said filtered side of said filter element;
a sheet of filter paper disposed within said cup portion and covering said aperture to prevent unfiltered fluid from passing through to said filtered side of said filter element;
said cup portion having a raised portion extending above said aperture, and said raised portion having a pair of apertures extending therethrough; and
said relief valve having a flexible rubber member captured within one of said apertures in said raised portion, and said flexible rubber member having an extended portion covering the other of said pair of apertures wherein said extended portion of said flexible rubber member flexes away from said other aperture in response to a predetermined level of pressure across said filter element thereby releasing unfiltered fluid through said other aperture wherein said fluid passes through said sheet of said filter paper and said aperture in said cup portion to said filtered side of said filter element.