Abstract: A is adapted to form a flanged ring including an elongated curved extension from an elongated straight flange with an elongated base and an elongated protrusion extending from the elongated base. The device comprises a first pair of opposed surfaces adapted to compress an elongated protrusion of a flange to increase a length of the elongated protrusion. The device further includes a second pair of opposed surfaces adapted to compress an elongated base of a flange to increase the length of one portion of the elongated base relative to another portion of the elongated base. A flanged ring is also provided that is formed by process comprising the steps of providing a device including a first pair of opposed surfaces and a second pair of opposed surfaces.

Abstract: An insulated duct. The duct includes a concentric arrangement of a flowpath-defining inner wall and an outer wall, with insulation disposed in the annular region between the walls. A portion of the axial length of the annular region away from the end of the duct is filled with lower-density insulation, while another portion adjacent the duct end is filled with higher-density insulation than that of the portion away from the duct end. The higher-density insulation helps keep the concentric walls in their as-manufactured relative spacing and shape. Flanges may be attached to one or both of the walls at the ends of the duct to facilitate joining of adjacent duct segments.