Abstract: A filter housing of synthetic material having a housing head (1) with an inside of synthetic material having an inlet part (3), an outlet part (2) and a cylindrical connector part (b 4) having an outwardly threaded neck (9) and a sealing surface (12), the housing portion (5) having an inside of synthetic material and an open end including a ring-shaped projection (13) and a sealing element (14), the filter housing further having a removable union nut (6) removably engaging the threaded neck (9) of the cylindrical connector part (4) and the ring-shaped projection (13) of the housing portion (5), wherein the inlet part (3) and the outlet part (2) are each cylindrical in form and each have an outwardly threaded neck (7, 8) and a ring-shaped groove (10, 11) in the edge for receiving an elastic sealing element.