Infusion system configurations and assemblies facilitate routing of infusion circuit tubing lines. Tubing lines are routed into and out from compartments of a shielding assembly for the infusion system, at locations which prevent kinking and/or crushing of the lines, and/or provide for ease in assembling the circuit. A plurality of the lines may be held together by a support frame to form a disposable infusion circuit subassembly, that can further facilitate routing of the lines.