Flat-oval tee

Before you start

• Confirm the flat-oval size, major and minor axis orientation, material, pressure class, joint type, and support detail against the approved drawing.
• Inspect the duct for sidewall dents, flattened ends, twisted axes, damaged beads, split seams, and shipping damage before lifting it.
• Check that the mating pieces use the same oval profile. A round-looking end and a truly matched flat-oval end are not the same thing.
• Stage the correct fittings, joint hardware, approved fasteners, sealant or gasket system, supports, lifting equipment, and hand tools before starting.

Lay it out

1. Confirm the tee orientation, main-flow direction, branch angle, branch size, and major-axis alignment.
2. Field-check the main and branch centerlines before lifting.
3. Verify that branch access and damper locations will remain usable.

Set and support it

1. Support the tee body independently before connecting the branch.
2. Support the main on both sides where the fitting weight requires it.
3. Install or mark the first branch hanger so the branch cannot rotate the tee.

Make the connection

1. 1

   Set the supported tee on the main centerline.

2. 2

   Align and connect the upstream main end.

3. 3

   Recheck the tee rotation and connect the downstream main.

4. 4

   Bring the branch section to the outlet without pulling the tee sideways.

5. 5

   Complete the branch connection.

6. 6

   Fasten and seal all three joints.

7. 7

   Load all supports and verify the tee remains aligned.