Patent ID: 8157989

Claim:
A filter comprising: a housing providing a cavity; a filter cartridge assembly including a media pack arranged within the cavity and having a central opening extending between opposing ends of the media pack; and a relief valve supported on the filter cartridge assembly and in sealing engagement with the housing, wherein a center tube is arranged in the central opening of the media pack, the center tube extending out of the central opening beyond one of the opposing ends to provide a first end, the relief valve supported on the first end, and wherein the center tube is a unitary structure, wherein said center tube supports said media pack and has a plurality of openings on a longitudinal axis for connecting said media pack and said central opening, wherein the center tube includes first end openings in a portion of the center tube extending beyond the one of the opposing ends of the media pack, and the first end openings are blocked by a leg of the relief valve when the leg is in a closed position and unblocked by the leg when the leg is in an open position, and wherein the relief valve includes a plurality of protrusions disposed on an inner surface of the leg, the protrusions projecting radially inward from the inner surface toward the longitudinal axis.