Abstract: A filter unit for filtering pressurized liquid carrying solid contaminants, comprising a housing having a cavity, an unfiltered liquid inlet port, and a filtered liquid outlet port. The filter unit also has a filter element having a generally cylindrical shape positioned within the housing, an interior, and a porous filter sleeve having an exterior face, the interior of said filter element in fluid communication with the filtered liquid outlet port and the exterior face of the sleeve of said filter element in fluid communication with the unfiltered liquid, so that, in operation, unfiltered liquid carrying solid contaminants flows into the cavity of the housing through the unfiltered liquid inlet port, the filter element filters the solid contaminants from the liquid, and the filtered liquid passes through the sleeve of the filter element to the interior thereof before exiting the filter unit via the filtered liquid outlet port.