The following is an excerpt from the NAIMA's Fibrous Glass Duct Construction Standards, Fourth Edition, 2001.
(Editor’s note: The following is an excerpt from the North American Insulation Manufacturers Association’s Fibrous Glass Duct Construction Standards, Fourth Edition, 2001.)
Machine fabrication is fast, accurate, repeatable, and usually more productive than hand fabrication. _ Grooving machines can cut all of the corner fold cuts for a one-piece straight module of fibrous glass duct board, plus cutting to correct stretch-out dimensions and finishing the longitudinal seam edges with staple flap, all in one pass. Two-piece “L”, two-piece “U”, and four-piece duct components can also be cut on grooving machines.