Patent ID: 7638045

Claim:
A liquid filtration system comprising a liquid filter and a filter head, the liquid filter comprising a pressure vessel and a filter cartridge removably received inside said pressure vessel, wherein: the filter cartridge comprises an elongated cartridge body having an longitudinal axis and a cartridge body diameter and a cartridge cap connected to the cartridge body at a top end of the cartridge body, the cartridge body defining a cartridge interior space receiving filter media, and the cartridge cap having a neck upending centrally from said cartridge cap and defining both a fluid inlet and fluid outlet, into and out of the cartridge interior space respectively, wherein the neck has a neck outer diameter smaller than said cartridge body diameter; the pressure vessel having a pressure vessel interior space receiving said filter cartridge except for said neck, the pressure vessel comprising an elongated pressure body having a longitudinal axis and a pressure cap connected to the pressure body at a top end of the pressure body, the pressure cap having a cap wall transverse to the longitudinal axis of the pressure body and an aperture extending through, and centrally located in, said cap wall through which aperture extends said neck of the filter cartridge to fluidly seal both said fluid inlet and said fluid outlet to said filter head; wherein said pressure vessel mechanically connects to said filter head and the pressure vessel does not fluidly seal to said filter head; and wherein said pressure cap is disconnectable from the pressure vessel for removal of the filter cartridge from the pressure vessel, including removal of said neck from the aperture, so that another of said filter cartridges is insertable into the pressure vessel and the pressure vessel is reusable in said filter head.