TDC/TDF Flanged Connections
Apprentice sees flanged duct and is unsure whether the joint is TDC/TDF/Ductmate, how the gasket should sit, and how to pull the duct faces into alignment without forcing the run crooked.
What This Helps With
Apprentice sees flanged duct and is unsure whether the joint is TDC/TDF/Ductmate, how the gasket should sit, and how to pull the duct faces into alignment without forcing the run crooked.
Apprentice words: flange duct
Trade terms: transverse duct connection, rolled flange, TDC/TDF, cleats and corners
Check First
What Not To Do
Do not call for rivets as the normal TDC/Ductmate connection. Do not use corners, bolts, drift pins, clamps, or screws to drag a crooked duct run into place. Do not crush the gasket or flange.
What can go wrong: Leaving gaps at corners or skipping gasket
Better Foreman Question
This flanged joint is close but not pretty at the corners. Duct is level/aligned. Do you want cleats, or if cleats are unavailable, 5/16 self-tappers in the flange as the fallback?
Verify With
Reference type: manufacturer install instructions
Source to verify: Duct connection system maker (e.g., Ductmate/Nexus) install data; SMACNA
Safe wording: TDC/Ductmate details vary by system and spec. Gasket on one end, corners on the joining duct, alignment/level matters more than pretty corners. Verify cleat/screw fallback with foreman/spec.