I am sorry for attracting such harse comments on an innocuous post!

"Do you mean your system is qualified by B31.3 with SE< =SA and still has troubles due to thermal strain?"

Theremal cycles undergone are too small in number, at temperature much below creep temperature! So, doubting the expansion load to be primary - like considered for pipe support design.

Had both piping and support structural details considered in same input, this load could have been considered as secondary, too; isn't it right!

"Provide two subsequent anchors on the same straight run pipe" - one does not provide in normal situation.

In abnormal situation of high frequency multiphase flow, the requirement of raising natural frequency above 16 Hz is a requirement which can be attained by putting rigid strut. This give rise to a situation of restricting thermal expansion significantly. In size reduction - reducer small diameter end - weld leakage is appearing regularly.

It is a highly constrained and axially stiff piping with many SIFs located very near to each other - a special case I referred to.

reg,
sam

PS; We never doubt in code!