Do not expect loose loop hangers to control side-to-side drift by themselves.
Check
Watch movement during startup if safe.
Check rod plumb and pipe centerline drift.
Look for vibration source or equipment pull.
Identify which hangers need lateral control.
Do not over-restrain where expansion/movement is required.
Steps
Watch movement during startup if safe.
Check rod plumb and pipe centerline drift.
Look for vibration source or equipment pull.
Identify which hangers need lateral control.
Do not over-restrain where expansion/movement is required.
Say this to your foreman
The round duct at [location] is snaking sideways in loop hangers. I checked rod plumb and movement. Do you want rigid saddles/trapeze supports added at intervals?