An infusion device (100) comprising an infuser base (105), a cannula (115) and a ferrule (120). The infuser base (105) having a bore (104) extending therethrough, the bore (104) having a distal and proximal ends the proximal end having an inside first diameter. A flange (135) extends radially outward from the cannula proximal end. The cannula (115) is positioned in the bore (104) such that the flange (135) is positioned adjacent the shoulder (109). The ferrule (120) has an insertion portion (122), having an outside second diameter which is substantially equal to the first diameter, and a tapered portion (125) extending from the insertion portion (122). The ferrule (120) is positioned in the bore (104) such that the insertion portion (122) and a portion of the tapered portion (125) are received in the cannula proximal end and the flange (135) is compressed between the shoulder (109) and the tapered portion (125) to define a seal (160) between the cannula (115) and the ferrule (120).
