Connect a transition with S-and-drive

Before you start

• Confirm the duct size, end construction, pressure class, seal class, and joint shown on the approved shop drawing.
• Inspect both duct ends for crushed corners, torn locks, bowed panels, loose reinforcement, or shop damage before lifting them into place.
• Make sure the supports are already installed or the sections are otherwise held so the joint is not carrying the weight of the run.
• Stage the correct S-cleats, drive cleats, sealant, hand tools, clamps, and access equipment before starting the joint.

Lay it out

1. Mark the top, bottom, flat side, and airflow direction before lifting the transition.
2. Verify the large and small dimensions and the fabricated length against the field opening.
3. Check that the taper will clear structure, insulation, access doors, and adjacent trades.

Set and support it

1. Support the transition body so neither tapered panel is used as a lifting point.
2. Set the large end at the correct elevation and rotation.
3. Provide support near the small end so the fitting does not act like a lever on the first joint.

Make the connection

1. 1

   Fit the S-cleats and connect the large end while the transition is stable.

2. 2

   Confirm the flat side and centerline remain in the approved orientation.

3. 3

   Align the small end with the next duct section without twisting the transition.

4. 4

   Start both side drives and seat them evenly.

5. 5

   Finish the drive ends, seal the joints, and verify the transition support.

6. 6

   Inspect the internal path for a lip, twist, or abrupt field deformation.