Dear T.J.N,

Thanks for your reply. But, the problem with us,engineers is that we swear by ASME B 31.3 code, not by our own opinions.

While talking about sign of horizontal loads, I have not talked about treating of the two sides of an anchor in piperack in separate analyses; there, if these thermal expansion forces from two separated analyses balance, let them be.

But, I have concern about self-springing or shake down. If you read clauses 319.5, 319.2.3 & Eqn 23 of clause 319.5.1 of ASME B 31.3, you can notice that the design of anchors & restraints in piping systems can't ignore effect of self-springing. As a conservative approach, instead of C1 in Eqn 23 of clause 319.5.1 of ASME B 31.3:2002, I have considered C1=1, considering racks can be safely designed for reversible axial loads, without much problem.

regards,
sam