Abstract: A filter unit includes a housing, a first filter and a second filter disposed in the housing, and a liquid flow path that extends through the first and second filters in series. The first filter includes a first axial end affixed to the housing and a first filter media. The second filter includes a first axial end affixed to the housing at the outlet and a second filter media. The liquid directed radially outward through the first filter media and radially inward through the second filter media. A method of filtering a liquid within a filter unit includes passing the liquid radially outward through a first filter media of a first filter, directing the liquid from the first filter to a second filter, and passing the liquid radially inward through a second filter element of the second filter.

Abstract: A filter unit for filtering liquid includes a housing with an inlet and an outlet, a first filter and a second filter disposed in the housing, and a liquid flow path extending from the inlet to the outlet. The liquid flow path directs the liquid one of radially inward and radially outward through a first filter media of the first filter and the other one of radially and directs the liquid the other one of radially inward and radially outward through a second filter media of the second filter. A method of filtering a liquid within a filter unit includes passing the liquid one of radially inward and radially outward through a first filter media of a first filter and passing the liquid the other one of radially inward and radially outward through a second filter media of a second filter.

Abstract: A removable filter cartridge includes a filter housing containing a filter for filtering liquid and a sealing valve assembly coupled to the filter housing and for removably coupling the filter cartridge to a filter head. The sealing valve assembly include an inlet passageway and an outlet passageway. The sealing valve also including an inlet sealing valve that blocks the inlet passageway and an outlet sealing valve that blocks the outlet passageway while the filter cartridge is uncoupled from the filter head. A method of retrofitting a filter housing includes removing the filter housing from a filter head, coupling a sealing valve assembly to the removable filter to form a removable filter cartridge, and coupling the removable filter cartridge to the filter head.

Abstract: A removable filter cartridge includes a filter housing containing a filter, a sealing valve coupled to an open end of the filter housing and configured to removably couple the removable filter cartridge to a filter head. The sealing valve has an open position and a closed position that seals the filter housing, and is configured to maintain a seal of the filter housing while uncoupled from the filter head. A sealing valve includes a first end to be removably coupled to a filter head and a second end to be coupled to a filter housing to form a removable filter cartridge. A method of retrofitting a filter housing includes removing the filter housing from a filter head, coupling a sealing valve to the filter housing to form a removable filter cartridge, and removably coupling the removable filter cartridge to the filter head.

Abstract: A removable filter cartridge includes a filter housing containing a filter and a sealing valve coupled to an open end of the filter housing. The sealing valve configured to removably couple the removable filter cartridge to a filter head. An open position allows fluid to flow into and out of the internal volume of the filter housing. A closed position seals the filter housing. A method for retrofitting a filter housing includes removing the filter housing from a filter head, coupling a sealing valve to the removable filter to form a removable filter cartridge, and coupling the removable filter cartridge to the filter head.