An infusion part comprising a cannula part (7) and a fluid path, whereby a sealing (18) is positioned between the cannula part and the inlet/outlet opening (12) of the fluid path when the cannula part is in position for use in order to keep the fluid path to the cannula tight. The sealing is surrounding the inlet/outlet opening and/or the distance d1 between a centre line c of the cannula part and a point on the outer surface of the cannula part positioned at or above the upper edge of the sealing is larger than the distance d2 between the centre line c of the cannula part and a point on the outer surface of the cannula part positioned at or below the lower edge of the sealing.
