A membrane medical filter for e.g. dialysis has a housing with an end-cap (30). The cap has a passage (12) linked to the inlet/outlet (20) and an inlet/outlet chamber (10). Incoming fluid emerges from the passage (12) radially past and are redirected by cambered guide vanes into the inlet/outlet passage (10). - The passage (12) discharges to the inlet/outlet chamber (10) to a bundle of hollow fibers. The passage diameter is les than that of the fiber bundle. The passage (12) is circular and located at the centre of the fiber bundle. The passage has a converging cross-sectional profile in the direction of fluid flow.
