Branching Off A Main...
Branching Off A Main...
(OP)
I forget...what is the rec'd minimum tolerance to leave when cutting a branch duct into a main? Assume cutting a rectangular duct into a rectangular duct. Hmm, what about a small circular duct cut into a duct of larger diameter?
I believe you must maintain a 2" minimum tolerance correct? If a 4x6 branch is being cut into the side of a main, the main must be at least 10 inches deep, correct? This accounts for 2" above and below the branch, right?
C.George
I believe you must maintain a 2" minimum tolerance correct? If a 4x6 branch is being cut into the side of a main, the main must be at least 10 inches deep, correct? This accounts for 2" above and below the branch, right?
C.George





RE: Branching Off A Main...
Thanks,
CuriouslyGeorge
RE: Branching Off A Main...
Bellmouth for taps to vav and cv boxes
They make rectangular heel taps and oval taps too
They come with an adhesive gasket and holes for sheetmetal screws to secure to the main duct
For taps to diffusers I spec Buckley AMTD, same gasket, etc
united mcgill also makes conical taps
it all depends upon the product
RE: Branching Off A Main...
Yes, the second thing you said. 2" total.
You might have to have a smaller branch if you use something like a conical fitting because it tapers down to the branch size. For instance, an 8" branch off of a 10" main is acceptable, but the conical fitting OD might be close to 10" so it might not work.
RE: Branching Off A Main...
Regards,