Air conditioning system tube with thermoplastics walls includes a corrugated pipe sandwiched between two smooth pipes to enhance heat insulation

摘要

The air conditioning system tube with thermoplastics walls has a smooth pipe (2) bonded to an outer corrugated pipe (4) in turn bonded to an external smooth pipe (3). Also claimed is a process utilizing the tube. CLAIMED PROCESS - The process permits selective use of e.g. polyethylene and polypropylene pipes (2,3,4), to produce a heat-insulating cavity (5) round pipe (4).