Bending of pipe to ASME B31.3 : dimensions

[Esp1holm]

Does ASME B31.3 Module 6. "Bending and Forming" specify which should be used as bending radius for 3D bends; Nominal or outer diameter of pipe?

Thanks, Espen

 

[hokie96]

In my experience, nominal diameter is used for determining bend radius.

 

[beyee]

Nominal diameter is used not only for determining bend radius. But, also for determine hot or cold process follow its and determine heat treatment after bent process.
We may use bend radius with R/D = 1.5, following with squezee and sizing after bend.

For your reference :
1. For material Carbon Steel (P-1), post cold heat treatment is never required
2. For material P-4 and P-5A, post cold heat treatment is required if R/D < 2
3. For material P-5B, post cold heat treatment is required if :
A. R/D < 2.5 shall normalizing and tempering
B. R/D >= 2.5 shall stress relieving

Regards