New Technical Resource Bulletin (TRB)

From the Technical Resources Department. Update to the SMACNA HVAC Duct Construction Standards, Metal and Flexible, Fourth Edition, Figure 2-18 Corner Closures - Flanges.

This technical resources bulletin updates the language for corner fastening requirements used in conjunction with the T-25a and T-25b flanged transverse joint assembly.

TRB #01-25 Figure 2-18 Corner Closures - Flanges

Nov 24, 2025 — Member Update

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