Patent ID: 8211518
Filing Date: 2012-07-03
Classification: F16L,Y10T

Abstract:
1. A duct section, for conducting gaseous fluid from a first location to a second location, the duct section comprising: a primary duct member, having a first end and a second end; a multilayer shroud, having a first end and a second end, the multilayer shroud being positioned radially outwardly from and circumferentially surrounding at least a portion of the primary duct member, the primary duct member and the multilayer shroud defining an axially extending annular space therebetween; a first closeout collar, permanently and sealingly affixed to the first end of the multilayer shroud and further permanently and sealingly affixed, at least indirectly, to the first end of the primary duct member, at a position proximate the first end of the primary duct member; a second closeout collar, permanently and sealingly affixed to the second end of the multilayer shroud and further permanently and sealingly affixed, at least indirectly, to the second end of the primary duct member, at a position proximate the second end of the primary duct member; the first and second closeout collars closing off opposite ends of the axially extending annular space defined by the primary duct member and the multilayer shroud, to preclude the flow of gases therefrom said space, and to prevent rotation of the multilayer shroud relative to the primary duct member; the shroud having an inner surface and an outer surface, with a metallic inner layer positioned at the inner surface; and a polymeric outer layer, bonded to the outer surface of the metallic inner layer.