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Apprentice answer

Why do parallel 45-degree offsets need different travel lengths

3rd YearMeasuring, Layout & Field MathCheck first

Parallel offsets do not always use identical travel pieces. The outside run travels a longer centerline path, so spacing has to be laid out from pipe centerlines, not copied by eye.

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Plain-English answer

When two parallel round runs offset around the same obstruction, the outside run has to take a wider path. If both travel pieces are cut the same, the runs can pinch together or collide at the turn.

Lay out both pipe centerlines, preserve the required spacing through the offset, and adjust the outside travel length to match the larger path. Check hanger positions before fastening so the two runs stay parallel.

Ask Foreman

The two parallel spiral runs are colliding at the 45 offset because the travel pieces were cut the same. I laid out the centerline spacing and outside travel correction. Do you want me to recut the outside spool?

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Use this as training guidance. Foreman direction, approved drawings, project specs, manufacturer instructions, employer safety policy, and AHJ/code requirements always control the final answer.

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