Abstract: A compressor system arrangement of the type arranged to compress a liquid gas/mixture and discharge same into a separator vessel where the compressed gas is separated from the liquid and passed to a clean compressed gas outlet. To make such compressor systems competitive with other gas compressors it is necessary to make the overall system package smaller and to achieve this in accordance with the present invention, the compressor (7) is housed substantially within the separator vessel (2) and the filter element (4) is annularly disposed adjacent to a circumferential wall (22) of the separator vessel (2) with the filter element 4 being preferably housed within a dry sump compartment defined by a partition wall (40) with one or more access openings (42,63,3) located in an upper region of the separator vessel (2) in a position of use of the compressor system.