Looking for

I am looking for an extrusion process to extrude an 18" to 24" diameter, 0.030" to 0.060" thick walled tube in TPU.  Also, to add to the complexity this is to be a coextrusion where we will have a thin layer of adhesive grade tpu on the outside.
We currently make this type of product for diameters up to 12" but the bigger we go the harder it is to cool down and control.  We extrude downward and we think that with our current process, the weight of the material coming out of the die would draw down to fast and cause problems.
Has anybody ever seen the extrusion of such tubes.
 
Thanks