A flow sensor sub-assembly for sensing flow of a fluidic medicament comprising: a flow tube assembly through which said medicament flows having: a flow tube having a lumen, an outside diameter, a first end, and a second end; an inlet fitting having a conical, distal orifice with an abutting shoulder, wherein said conical orifice is sized for insertion of either end of said flow tube; and an outlet fitting having a conical, proximal orifice with an abutting shoulder, wherein said conical orifice is sized for insertion of either end of said flow tube; a first transducer arranged at the inlet fitting; and, a second transducer arranged at the outlet fitting, wherein said conical orifices (172, 197) of said inlet fitting and said outlet fitting are two-part tapers having an intermediate shoulder (173, 193) approximately half-way along the length of said taper, wherein the conical orifice of said inlet fitting has a distal taper section designed to allow capillary action to draw fitting adhesive into the void between the exterior of the flow tube and the interior surface of the conical orifice during assembly and the conical orifice includes a proximal taper section which creates a gap between the exterior surface of the flow tube proximal to the distal end which does not fill with a fitting adhesive during assembly and provides an air gap, and wherein the conical orifice of said outlet fitting has a proximal taper section designed to allow capillary action to draw fitting adhesive into the void between the exterior of the flow tube and the interior surface of the conical orifice during assembly and the conical orifice includes a distal taper section which creates a gap between the exterior surface of the flow tube distal to the proximal end which does not fill with a fitting adhesive during assembly and provides an air gap. a flow tube assembly through which said medicament flows having: a flow tube having a lumen, an outside diameter, a first end, and a second end; an inlet fitting having a conical, distal orifice with an abutting shoulder, wherein said conical orifice is sized for insertion of either end of said flow tube; and an outlet fitting having a conical, proximal orifice with an abutting shoulder, wherein said conical orifice is sized for insertion of either end of said flow tube; a flow tube having a lumen, an outside diameter, a first end, and a second end; an inlet fitting having a conical, distal orifice with an abutting shoulder, wherein said conical orifice is sized for insertion of either end of said flow tube; and an outlet fitting having a conical, proximal orifice with an abutting shoulder, wherein said conical orifice is sized for insertion of either end of said flow tube; a first transducer arranged at the inlet fitting; and, a second transducer arranged at the outlet fitting, wherein said conical orifices (172, 197) of said inlet fitting and said outlet fitting are two-part tapers having an intermediate shoulder (173, 193) approximately half-way along the length of said taper, wherein the conical orifice of said inlet fitting has a distal taper section designed to allow capillary action to draw fitting adhesive into the void between the exterior of the flow tube and the interior surface of the conical orifice during assembly and the conical orifice includes a proximal taper section which creates a gap between the exterior surface of the flow tube proximal to the distal end which does not fill with a fitting adhesive during assembly and provides an air gap, and wherein the conical orifice of said outlet fitting has a proximal taper section designed to allow capillary action to draw fitting adhesive into the void between the exterior of the flow tube and the interior surface of the conical orifice during assembly and the conical orifice includes a distal taper section which creates a gap between the exterior surface of the flow tube distal to the proximal end which does not fill with a fitting adhesive during assembly and provides an air gap.