Hi all,

Why the ASME B31.3 Code doesn´t use the "Sy" factor (Specified Minimun Yield Strenght) for compare with the allowables stress for a A106 B Material? How can i do to compare the allowables strees when i use this material and code of reference?

How can i do to compare the allowables stress when the piping system have two type of materials?

Many thanks and regards!

B31.3 dies not use Sy for allowable stress because it is a fatigue based Code. See paragraph 302.3.2 for a discussion of how the allowable stresses are calculated.

You simply change the material input to each element when your material changes. You could build a CAESAR II model where each element was made of a different material and the software would not have a problem with this issue.

It appears that you have a lot of catching up to do. I recommend you read the B31.3 Code thoroughly and work through several of the sample problems included with your copy of CAESAR II before doing anything of consequence.