An infusion device comprising an infuser base, a cannula and a ferrule. The infuser base having a bore extending therethrough, the bore having distal and proximal ends and defining a shoulder therebetween. The cannula having distal and proximal ends, the proximal end having an inside first diameter. A flange extends radially outward from the cannula proximal end. The cannula is positioned in the bore such that the flange is positioned adjacent the shoulder. The ferrule has an insertion portion, having an outside second diameter which is substantially equal to the first diameter, and a tapered portion extending from the insertion portion. The ferrule is positioned in the bore such that the insertion portion and a portion of the tapered portion are received in the cannula proximal end and the flange is compressed between the shoulder and the tapered portion to define a seal between the cannula and ferrule.
