Accepted Industry Practice for Industrial Duct Construction
This guide is a compilation of accepted industry practices and construction techniques having received wide acceptance for the fabrication and installation of industrial duct systems. Covers round (long-seam and spiral) duct from 4 in. to 60 in. in diameter, reinforced or unreinforced, for operation from 4 in. to 20 in. wg positive or negative pressure, and from ambient to 650ºF for carbon or stainless steel, 400ºF for galvanized steel, and 120ºF for aluminum. Also rectangular duct fabricated from panels from a few inches up to 5 ft wide, all welded, Pittsburgh, grooved seam pipe lock or standing seam joined duct, for operation from 4 to 20 in. wg positive or negative pressure, and for the same materials and temperature limits as round duct. Also includes chapters on industrial applications, material properties, hangers and supports, fittings, vents, doors, discharge ducts (small stacks) and surface preparation of metals.
Technical Manual - 210 pages
2nd edition, 2008
The Sheet Metal and Air Conditioning Contractors' National Association, recognizing the popularity of this guide since it was first published in 1975, has sought to update the information it contains on the basis of the more recent editions of the Round and the Rectangular Industrial Duct Construction Standards of 1999 and 2004, but maintaining the narrower scope, table presentation and graphics of the original Accepted Industry Practice for Industrial Duct Construction.
This guide is a compilation of standards and construction techniques which have received wide acceptance for the fabrication and installation of ducts designed to convey air and gases, usually contaminated with particulates, fumes, vapors or corrosive aerosols.
Industrial duct is a broad classification of ductwork used in industry for many diverse applications, from air distribution and ventilation exhaust in Class 1 systems, to pneumatic conveying in Classes 2, 3 and 4, to conveying of industrial exhausts containing corrosive aerosols. These contaminated flows are usually conveyed at velocities in excess of 2,000 feet per minute and frequently at static pressures in excess of positive or negative 10 inch water gage. While there may sometimes appear to exist an overlap between industrial ventilation (Class 1) and HVAC applications in the under 10 in. wg category, closer inspection reveals marked differences in performance, maintenance and structural requirements between the two. Unfortunately, industrial ventilation duct is sometimes specified per SMACNA's HVAC Duct Construction Standards, when perhaps specifying a industrial Class 1 system would result in a more satisfactory installation.
MAJOR CHANGES FROM THE PREVIOUS EDITION
Created a new chapter structure somewhat similar to that in the Round and Rectangular Duct Construction Standards. Combined and reorganized sections of the 1st edition into the new chapter structure. For consistency, the material in chapters two and three was taken directly from the Round and Rectangular manuals. Created a new chapter four with all new duct selection tables, maintaining the format and style of the first edition, but consistent with the information in the Round and Rectangular manuals. Added many figures for seams and joints to complete the duct construction features of the manual. Added new chapters for Hangers and Supports, Fittings, Vents, Doors, and basic information on Stacks and Discharge Ducts. Updated the surface preparation guidance with the latest information from the Society for Protective Coatings (SSPC). Created a separate chapter of updated references and placed useful welding symbols into an Appendix.