Patent ID: 7699078

Claim:
A method for manufacturing an insulated duct comprising the steps of: forming a first insulated duct segment, wherein the first duct segment has a first outer duct, a first inner duct placed inside the first outer duct, and a first annular space between the first inner duct and the first outer duct, and wherein the first annular space has been injected with an insulating material; forming a second insulated duct segment, wherein the second duct segment has a second outer duct, a second inner duct placed inside the second outer duct, and a second annular space between the second inner duct and the second outer duct, and wherein the second annular space has been injected with an insulating material; connecting the first inner duct to the second inner duct; connecting a fill joint between the first outer duct and the second outer duct to create a fill joint annular space; and injecting fluidized insulating material into the fill joint annular space.