Element with bypass sealing element

Abstract

A filter element includes in an end cap assembly an internal bypass valve such that the bypass valve can be replaced along with the filter element. Additionally or alternatively, the filter element end cap assembly has a reverse flow valve for enabling reverse flow across the filter element without passage through filter element.

1 . A filter element comprising a filter media, and an end cap assembly at one end of the filter media; the end cap assembly including an end cap that includes an annular peripheral flange portion for engaging an end face of the filter media, and a central tubular portion forming with the filter media an interior fluid flow passage, the central tubular portion having an opening at an axial end thereof and an annular wall including at least one radial bypass flow passage for allowing fluid supplied to one side of the central tubular portion to bypass the filter element and flow to an opposite side of the central tubular portion; and a bypass flow valve axially movable within the central tubular portion between a closed position blocking flow from the radial bypass flow passage to the opening at the axial end of the central tubular portion and an open position permitting flow of fluid from the radial bypass flow passage to the opening at the axial end of the central tubular portion, and wherein the bypass flow valve is responsive to a prescribed pressure differential across the central tubular portion for moving the bypass flow valve from the closed position to the open position to permit flow through the bypass flow passage. 
     
     
         2 . A filter element as set forth in  claim 1 , wherein the end cap has an annular bypass valve seat surrounding the interior flow passage, and the bypass flow valve has an annular valve sealing surface for seating against the bypass valve seat to block flow from the radial bypass flow passage to the opening at the axial end of the central tubular portion. 
     
     
         3 . A filter element as set forth in  claim 2 , wherein the annular valve sealing surface is formed by an axially protruding peripheral lip on the bypass flow valve. 
     
     
         4 . A filter element as set forth in  claim 3 , wherein the bypass flow valve has a tubular portion telescopically movable within the central tubular portion, and the peripheral lip protrudes from an axial end face of the tubular portion of the bypass flow valve. 
     
     
         5 . A filter element as set forth in  claim 4 , wherein the tubular portion has a radially outwardly protruding annular sealing portion for sealing against an interior surface of the central tubular portion at a location remote from the peripheral lip, which sealing portion is exposed to pressure of fluid in the bypass flow passage. 
     
     
         6 . A filter element as set forth in  claim 5 , wherein the bypass flow valve is resiliently biased toward its closed position, such that the bypass flow valve will be held in its closed position until the pressure differential across the annular sealing portion exceeds a prescribed amount causing the bypass flow valve to move to its open position. 
     
     
         7 . A filter element as set forth in  claim 6 , wherein the annular sealing portion is formed by a wiper seal oriented such that fluid pressure at its side in fluid communication with the bypass flow passage will cause the wiper seal to be pressed tightly against the interior surface of the central tubular portion. 
     
     
         8 . A filter element as set forth in  claim 1 , wherein the bypass flow valve has an opening bounded by an annular reverse flow valve seat, and wherein a reverse flow valve is carried by the end cap and movable between a closed position seated against the reverse flow valve seat for blocking the opening and an open position spaced from the reverse flow valve seat for permitting flow of fluid through the opening. 
     
     
         9 . A filter element as set forth in  claim 8 , wherein the reverse flow valve is resiliently biased toward its closed position, and the bypass flow valve is resiliently biased toward its closed position, such that the reverse flow valve and bypass flow valve will move in tandem when the pressure differential across the reverse flow valve exceeds the biasing force acting on the bypass flow valve. 
     
     
         10 . A filter element as set forth in  claim 9 , wherein the end cap has a central axially extending guide member, and the reverse flow valve is a poppet valve guided for axial telescoping movement on the guide member. 
     
     
         11 . A filter element as set forth in  claim 10 , wherein the guide member is located at the center of a spider support, and the spider support has circumferentially offset legs connecting the center of the spider support to the central tubular portion. 
     
     
         12 . A filter element as set forth in  claim 11 , wherein the spider support and central tubular portion are formed as separate parts that are joined together. 
     
     
         13 . A filter element as set forth in  claim 1 , in combination with a filter head and a housing removably attachable to the filter head, the filter head and housing surrounding the filter element when the housing is attached to the filter head. 
     
     
         14 . A combination as set forth in  claim 13 , wherein the filter element is removable from the housing, whereby the filter element can be replaced independently of the housing. 
     
     
         15 . A combination as set forth in  claim 13 , wherein the filter head includes an inlet passage and an outlet passage, and one of the inlet and outlet passages is in fluid communication with the bypass flow passage and the other is in fluid communication with the opening at the axial end of the central tubular portion. 
     
     
         16 . A combination as set forth in  claim 1 , wherein the central tubular portion has an annular groove retaining an annular seal for sealing to a wall of a socket in the filter head. 
     
     
         17 . A filter element comprising a filter media and an end cap assembly; the end cap assembly including an end cap at one end of the filter media, the end cap including a central portion forming with the filter media an interior passage and a bypass passage through the central portion for allowing fluid supplied to one side of the central portion to flow to an opposite side of the central portion without passing through the filter media; a bypass flow valve movable between a closed position and an open position respectively blocking and permitting fluid to flow through the bypass passage, the bypass flow valve including an outlet opening communicating the interior passage to outside the central portion; and a reverse flow valve carried by the end cap for closing and opening the outlet opening. 
     
     
         18 . A filter element as set forth in  claim 17 , wherein the end cap has an annular bypass valve seat surrounding the interior flow passage, and the bypass flow valve has an annular valve sealing surface for seating against the bypass valve seat to block flow from the radial bypass flow passage to the opening at the axial end of the central portion. 
     
     
         19 . A filter element as set forth in  claim 18 , wherein the annular valve sealing surface is formed by an axially protruding peripheral lip on the bypass flow valve. 
     
     
         20 . A filter element as set forth in  claim 17 , wherein the bypass flow valve has a radially outwardly protruding annular sealing portion for sealing against an interior surface of the central portion, which surface is exposed to pressure of fluid in the bypass flow passage. 
     
     
         21 . A filter element as set forth in  claim 17 , wherein the bypass flow valve is resiliently biased toward its closed position. 
     
     
         22 . A filter element as set forth in  claim 17 , wherein the reverse flow valve is resiliently biased toward its closed position, and the bypass flow valve is resiliently biased toward its closed position, such that the reverse flow valve and bypass flow valve will move in tandem when the pressure differential across the reverse flow valve exceeds the biasing force acting on the bypass flow valve. 
     
     
         23 . A filter element as set forth in  claim 17 , wherein the end cap has a central axially extending guide member, and the reverse flow valve is a poppet valve guided for axial telescoping movement on the guide member. 
     
     
         24 . A filter element as set forth in  claim 23 , wherein the guide member is located at the center of a spider support, and the spider support has circumferentially offset legs connecting the center of the spider support to the central tubular portion. 
     
     
         25 . A filter element as set forth in  claim 24 , wherein the spider support and central tubular portion are formed as separate parts that are joined together. 
     
     
         26 . A filter element as set forth in  claim 1 , in combination with a filter head and a housing removably attachable to the filter head, the filter head and housing surrounding the filter element when the housing is attached to the filter head. 
     
     
         27 . A combination as set forth in  claim 26 , wherein the filter element is removable from the housing, whereby the filter element can be replaced independently of the housing. 
     
     
         28 . A combination as set forth in  claim 26 , wherein the filter head includes an inlet passage and an outlet passage, and one of the inlet and outlet passages is in fluid communication with the bypass flow passage and the other is in fluid communication with the opening at the axial end of the central portion. 
     
     
         29 . A combination as set forth in  claim 1 , wherein the central portion has an annular groove retaining an annular seal for sealing to a wall in the filter head. 
     
     
         30 . A filter element comprising a filter media and an end cap assembly; the end cap assembly comprising: an end cap at one end of the filter media, the end cap including an annular peripheral flange portion for engaging an end face of the filter media, a central portion forming with the filter media an interior fluid flow passage, an outlet opening in the central portion; and a reverse flow valve carried by the end cap and movable from a closed position blocking the reverse flow passage and to an open position permitting flow of fluid through the reverse flow passage when fluid pressure at the outlet opening exceeds the pressure in the interior passage by a prescribed amount. 
     
     
         31 . A filter element as set forth in  claim 1 , wherein the end cap is bonded to the end of the filter media. 
     
     
         32 . A filter element as set forth in  claim 1 , wherein the filter media is tubular, and a second end cap is bonded to an end of the filter media opposite the first end cap. 
     
     
         33 . A filter element as set forth in  claim 1 , wherein the end cap has at least one radially deflectable tang for engaging a catch on a housing to hold the end cap to the housing. 
     
     
         34 . A filter element as set forth  claim 1 , wherein the tubular portion has an annular sealing portion for sealing against an interior surface of the central tubular portion that is exposed to pressure of fluid in the bypass flow passage.