Tying New Duct To Existing
Mismatch in size or class; leaks or restriction at the joint
Yellow / Check First3rdBatch 4
What This Helps With
Mismatch in size or class; leaks or restriction at the joint
Apprentice words: tie into existing duct
Trade terms: tie-in, mating existing, transition to existing
Check First
Existing size, condition, pressure class, and connection type
What Not To Do
Cut into existing before confirming it's isolated
What can go wrong: Assuming existing is the same class as new
Better Foreman Question
What's the existing size/class and how does the spec want the tie-in?
Verify With
Reference type: project drawings
Source to verify: Field survey; drawings; foreman direction
Safe wording: Emphasize verifying existing conditions; don't assume.