Unbraced length for circular steel pipe

[rowe]

Is there a limiting unbraced length for circular steel pipe in pure bending? (if not, then is the allowable tension and allowable compression the same?)

 

[WillisV]

1. No - it is impossible to fail a circular pipe in a lateral torsional buckling mode.

2. The shape develops the full plastic moment, so yes, it can develop yield stress at compression and tension faces.

Only thing you might need to worry about is local buckling. All this is covered in AISC 2005 Spec - Section F8.