Dear All,

In ASME B 31.3 2010 code for sustained, sl=sqrt((sa+sb)2+4st2)

Where Sa= Fa/Am

Fa= (due to pressure (p*Ai) + due to axial force)

But in ASME B31.3 code states that The sustained longitudinal force, Fa, includes the sustained force due to pressure, which is P*A.

In that statement, no where axial force term not used, whether it is taking or not. Or I missed any para.

Where as in expansion eq in 2012 code clearly mentioned about Fa= range of axial forces due to displacements

Please correct me if I am wrong

Any Comments on it.

B31.3 2010 and B31.3 2012 state the same in paragraph 320.2 and use the same equation (23d) here:
Sa=IaFa/Ap
where Fa equals longitudinal force due to sustained loads, e.g., pressure and weight.

yes i missed that .. now it is clear

Thank you