I am currently working on a piping system which is subject to cyclic operating conditions; I wonder if someone could confirm this for me:
assuming that the only cyclic condition occurring on this system is the fluctuation of temperature, is it still necessary that on top of the relevant (EXP) stress case with the proper "f" (stress reduction factor), a (FAT) stress case would have to be made? I have checked this in various calculations and the (EXP) case has been always the decisive case.
please advise.

thanks in advance