Patent ID: 6960245

Claim:
A filter arrangement comprising: (a) a first filter element having opposite first and second ends; an axial length between said first and second ends; and a plurality of flutes; (i) each of said flutes having a first end portion adjacent to said first filter element first end, and a second end portion adjacent to said first filter element second end; (A) selected ones of said flutes being open at said first end portion and closed at said second end portion; and selected ones of said flutes being closed at said first end portion and open at said second end portion; (b) a sleeve member circumscribing said first filter element; (i) said sleeve member having a cross-section that matches a cross-section of the first filter element; (ii) said sleeve member having a wall with a length that extends at least 30% of an axial length of the first filter element; (c) a seal member pressure flange extending radially from said sleeve member and fully circumscribing said sleeve member; (i) said seal member pressure flange having a perimeter in a shape that matches the sleeve member cross-section and the first filter element cross-section; (ii) said seal member pressure flange including first and second opposite axial surfaces; (iii) said seal member pressure flange extending radially from said wall of said sleeve member by a distance of at least 0.1 inch; and (d) a seal member secured to said first axial surface of said seal member pressure flange and circumscribing said sleeve member.