SMACNA ROUND DUCT CONST 2nd Edition, September 1, 1999
Round Industrial Duct Construction Standards
Includes all amendments and changes through Reprint , 2004
The scope of this manual includes the determination of the necessary construction details for the fabrication and installation of round metallic industrial duct work within the following general categories, and as further detailed in the scope of individual chapters, through a variety of both analytical and empirical methods:
• Fabricated using the longitudinal welded seam, grooved lock seam, and spirally generated lock seam techniques.
• From commercial grades of carbon, galvanized, or stainless steels, or aluminum of the various grades and types as described in Chapter 3.
• For a design pressure within the range from negative 30 in. wg (7500 Pa) to positive 50 in. wg (12,500 Pa).
• To be supported at intervals not exceeding 30 ft (9150 mm) for longitudinal welded seam pipe, and 20 ft (6100 mm) for spiral pipe.
• For a design temperature not exceeding the specific operating limits listed for each type and grade of metal included in Chapter 3.
• With a nominal diameter within the range of 4 to 96 in. (100 to 2440 mm)
• With a diameter-to-thickness ratio of less than 800 for all longitudinal seam ducts and 1800 for spiral pipe
• Listing of rated stiffeners, flanges, fasteners, hanger and support elements, and the methods for selecting them for specific structural loads.
• Catalogue of accepted industry practices for the fabricating and installation of round metallic industrial duct, with its fittings, appurtenances, accessories, insulation, cladding, hangers and supports.
There were three primary purposes behind the development of this manual:
• To develop minimum standards for the fabrication and installation of metallic round industrial duct systems.
• To develop new, and collect existing, duct construction practices and data to serve as an authoritative source of accepted industrial practices for contractors, design engineers, facility managers, and pollution control authorities.
• To provide an authoritative sources of documentation and terminology for operations involved in the construction and installation of round metallic industrial duct.