9/7/2010
7,790,256
Composite tube
Yamasaki et al of Furukawa Electric, Japan developed  a composite tube formed by covering an outer surface of a tube with a foam for use in cold heat medium piping of a heat exchanger, and water-supply/hot-water-supply piping.  The tube is formed by coextruding the solid tube surrounded by fan shaped bars of foaming layers around the tube.  (RDC 11/30/2010)