Stainless round exhaust duct

Before you start

• Confirm the stainless alloy, surface finish, service temperature, chemical exposure, pressure class, joint type, gasket or sealant chemistry, and approved welding procedure.
• Keep stainless separate from carbon-steel grinding dust, wire brushes, dirty carts, and contaminated work surfaces.
• Inspect every section for scratches, dents, embedded iron, damaged flanges, warped ends, and mismatched alloy markings.
• Stage dedicated stainless tools, compatible hardware, isolation materials, clean lifting equipment, and the approved joint components.

Lay it out

1. Confirm the round centerline, airflow direction, joint access, support locations, drainage or low-point concerns, and any exterior exposure.
2. Mark alloy or service-sensitive sections so they are not mixed with ordinary galvanized or a different stainless grade.
3. Plan seam and joint orientation so the full perimeter can be inspected and cleaned.

Set and support it

1. Use compatible broad bands, saddles, or trapezes that preserve the round shape.
2. Isolate stainless from carbon steel or other dissimilar support materials where the approved detail requires it.
3. Support both sections before closing the joint so the connection is not carrying dead load.

Make the connection

1. 1

   Clean the mating ends with dedicated stainless-compatible tools.

2. 2

   Align the sections and verify they remain round and on center.

3. 3

   Install the specified welded, flanged, or gasketed stainless connection for the service.

4. 4

   For a bolted or gasketed joint, seat the gasket evenly and tighten hardware in a balanced pattern.

5. 5

   For a welded joint, follow the qualified procedure, control distortion, and clean the completed weld as specified.

6. 6

   Install any required isolation, weather seal, or external protection.

7. 7

   Load the supports and inspect the full connection perimeter.