Continuous multilayered co-extrusion is a relatively mature technique that goes back to the 1970s, when it was first developed. Historically, two of the main limitations of the technology have been its limitation to sheet or film extrusion of materials of matched viscosities. Our group has recently overcome the Relating rheology and simulations to latter via the introduction of novel, non-square layering dies, which allowed systems with viscosity ratios up to 10 and elasticity ratios up to 100 to be micro-layered. In this work, we strive to overcome the former, by designing, manufacturing and validating a new system designed to multilayer tubes and pipes. Rheology and simulations are utilized to design and validate the multiplication system at research scale and to provide suggestions for upscale to industry. In particular, ANSYS® POLYFLOW® is utilized to evaluate shear, pressure, velocity profiles, and residence times through the designed flow path using commercially available commodity and engineering thermoplastics. Viscosity matched or mismatched layer systems are then evaluated using moving interface simulations to gain insight on layer structure during extrusion. Finally, the layer structure tracked using simulations was then compared with experimental results produced from a manufactured die. The presence of a weld line in this flow path required the outer mandrel to be rotated thereby superimposing a rotational deformation to the extrudate. The effect of shear rate and shear orientation on the elimination of the weld line and on the mechanical strength of the extrudate is also demonstrated and suggestions are made to produce viable multilayer tubing systems with high layer numbers and thin layer structures.