Flat-oval elbow

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 elbow angle, throat and heel direction, major-axis orientation, and outgoing centerline.
2. Check whether the elbow is intended for horizontal or vertical orientation.
3. Verify clearance around the full heel and throat before lifting.

Set and support it

1. Support the elbow body near its center of gravity instead of hanging it from one straight connection.
2. Use padded handling so the narrow sides and throat are not flattened.
3. Hold the elbow against rolling while the first joint is made.

Make the connection

1. 1

   Mark the inlet, outlet, top, and major-axis orientation on the floor.

2. 2

   Set the elbow on its fitting support and align the inlet tangent with the incoming run.

3. 3

   Connect the inlet using the approved oval joint system.

4. 4

   Recheck the elbow rotation and outgoing centerline.

5. 5

   Bring the outgoing straight section into alignment without twisting the elbow.

6. 6

   Complete and seal the second joint.

7. 7

   Load the supports and verify the elbow does not roll.