Process of making a fluid flow tube with varying cross section

摘要

A process for making a fluid tube (10) with a varying cross section comprising extruding a tube with a constant cross section, positioning the extruded tube in a die having substantially the cross section of the outer wall of the end tube and increasing the pressure inside the extruded tube, thereby deforming the tube, so that its outer wall confirms to the die form. The tube is a multiport extruded tube, in which the partition walls (16,17) are provided with at least one portion (19) with reduced thickness, the partition walls being broken during expansion.