Patent ID: 7166215

Claim:
A liquid filter assembly for connection to a filter head, the filter assembly comprising a pressure vessel and a filter cartridge removably received in the pressure vessel, the filter cartridge comprising: a generally cylindrical housing surrounding an interior volume receiving filter media and having a central longitudinal axis and a radial dimension transverse to the central longitudinal axis, the housing having a housing wall comprising an axial outer sidewall with an outer diameter, a generally radial outer bottom wall forming a cartridge bottom end, a generally radial outer top wall forming a cartridge top end, and the housing further having a neck upending axially from the top wall at or near said central longitudinal axis, wherein the neck has a neck outer diameter that is smaller than the outer diameter of said outer sidewall; wherein the neck comprises a neck wall with an outer surface, an inner surface, a neck lower end attached to the top wall, and a tube member generally coaxial with the neck wall and having a central axial passage, the tube member being spaced from the neck wall inner surface to create a neck annular passage between the tube member and the neck wall, wherein said central axial passage and said neck annular passage are liquid inlet and outlet passages for the filter cartridge; wherein the neck wall has a thickness adapted to withstand pressure in the neck annular passage at least 200 psi greater than pressure outside the neck wall; wherein said pressure vessel surrounds and reinforces the entire housing except for the neck, the pressure vessel having a generally radial upper wall with an aperture through which the neck protrudes and wherein said upper wall extends from near the outer sidewall of the housing across the top wall of the housing generally radially to the lower end of the neck wall to cover and reinforce the entire cartridge top end except for the neck; and wherein said pressure vessel comprises a first portion and a second portion adapted to be detached from each other so that the pressure vessel is openable for removing of said filter cartridge from the pressure vessel.