Abstract: A filter assembly comprises a filter (10) defining path for fluid passing to or from the filter (10). An adaptor (11) is connected to the filter (10) and provides a continuation of the path. The adaptor (11) is for mounting the filter (10) on a mounting plate (12) and carries one or more sealing rings (30, 37) that are engageable with the mounting plate (12). The adaptor (11) is made from a plastics material and one surface of the adaptor (11) is reinforced by contact with an annular reinforcing member (31) which may be of metal, particularly steel. This allows the flow path provided by the adaptor (11) to be maximized.

Abstract: A filter assembly comprises a housing (44) with an inlet (45) and an outlet (43). A filter module (10) is within the housing (44) and communicates with the inlet (45) and the outlet (43) such that fluid passing to the inlet (45) is filtered by the filter module (10) before passing to the outlet (43). The filter module (10) includes a filter membrane (11) of hollow cylindrical shape having an air throughput of at least 1300 normal cum/hr per 250 mm of the axial length of the membrane at an inlet pressure of 2 barg. Such a filter module (10) can be used in a process system (40) in which the module (10) supplies sterile air and is testable in situ.