摘要 |
A tubular jacket of flexible plastic film is telescoped over one of two spaced coaxial mandrels extending toward each other, duct end collars are secured respectively on the mandrels, opposite ends of a flexible helically reinforced core are strapped respectively to the collars, a flexible insulation blanket is wrapped around the core and taped adjacent opposite ends, the jacket is pulled over the blanket, the collars are released, and the collared duct is removed from the mandrels.
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