CHANTILLY, Va. -The second edition of SMACNA's Round Industrial Duct Construction Standards has been approved by the ANSI.

Recognition by the American National Standards Institute increases the potential that SMACNA's standards will be internationally adopted for industry and regulatory use. The approval will also encourage wider domestic use of SMACNA's standard by state- and local-code governing bodies as well as the design and engineering community, according to officials from the Sheet Metal and Air Conditioning Contractors' National Association.

The 642-page Round Industrial Duct Construction Standards deals with the design and construction of ducts in classes 1 to 5. It includes a spiral-duct chapter for classes 1 and 2 and covers design pressures ranging from 30-inch water-gauge negative to 50-inch water-gauge positive, plus carbon and galvanized-steel tables.

As alternatives to using tables, the publication has a manual calculation procedure using equations and examples, and offers optional calculation software.

The publication is available for sale at SMACNA's online bookstore at