How do I connect TDC/Ductmate duct sections?

TDC/Ductmate joints are a fit-up sequence: support both sections, put the gasket on one flange face only, bring the joining duct in level and aligned, seat the corners, then hold/lock the long flange spans with the approved cleats or fasteners. Drift pins can help line up corner holes after the duct is already close; C-clamps or locking clamps can hold the flange faces while you start hardware. The corners do not have to look picture-perfect by themselves - the duct faces need to match level, square, and alignment before you tighten anything.

Rectangular Duct & Fittings 3rd Year BLUE

Watch out

Do not use a drift pin, bolt, C-clamp, corner, cleat, or screw to force a badly misaligned TDC joint into place. Do not double-gasket the joint. Do not crush the flange/gasket with a clamp. Do not skip corners, cleats, or approved flange fasteners because the duct is already in the air.

Check

Support both pieces before pulling the joint together.
Put gasket on one duct/flange face only
do not double-gasket both sides.
Bring the joining duct in level and aligned before hardware starts.
Use drift pins lightly to line up corner holes only after the joint is close - not to drag a twisted run together.
Use C-clamps/locking clamps where needed to hold the flange faces while corners, cleats, or fallback screws get started
protect the flange face from crushing.
Seat the four corners and make sure the gasket did not roll, stretch, or gap at the corners.
Install required flange cleats/clips along the long spans
if none are available, ask before using 5/16 self-tappers through the flange as the fallback.
Tighten evenly
do not let bolts, pins, clamps, or screws drag the joint crooked.

Steps

Support both duct sections so the joint is not carrying weight.
Clean flange faces and verify the gasket path, corners, clips, bolts, cleats, drift pins, and clamps are staged.
Bring the flanges together level and aligned before using a pin or clamp.
Use drift pins only to line up close corner holes
use C-clamps/locking clamps only as controlled holding pressure on the flange.
Seat corners, install cleats/fasteners, tighten evenly, and re-check gasket before sealing or insulating.

Say this to your foreman

I'm connecting TDC/Ductmate at [location]. The gasket is on one flange face, the joint is close, and I may need drift pins/C-clamps to hold alignment. Do you want me to pin/clamp it, use standard cleats, or use 5/16 self-tappers in the flange if cleats are not available?