Static field route #1009

A rectangular-to-round transition collar does not match the spiral size

Spiral, Round Duct & Couplingsyellow

Do not force the spiral or crush the collar. Verify nominal size, actual OD/ID, connection type, shop tag, and whether a reducer/coupling or remake is required.

Open in Field Rescue Open category

Field checklist

Measure the collar outside diameter and the spiral/coupling size.
Check the shop tag and drawing callout.
Confirm if the connection needs a sleeve, reducer, coupling, or different fitting.
Support the pieces so alignment is not creating the mismatch.
Ask before crimping, cutting, or forcing.

Ask foreman

The transition collar at [location] measures [dimension] and the spiral/coupling is [dimension]. The drawing calls for [size]. Do you want a reducer/coupling, shop remake, or field adjustment?

Do not

Do not oval the spiral, beat the collar smaller, or seal over a connection that is not mechanically seated.

Why it matters

Round duct sizes can be nominal, but the job still needs the correct connection method approved before you force a bad fit.

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