hi , everyone.

I have a pipe system with a high temperature over 400 degree .

is it neccessary to take a fatigue analysis to it?

can anyone tell me the details of the steps ？

what is the difference between the Fac Coefficient which use to reduce the allowable stess in caesar and the fatigue Curve？

You may have a creep problem, but fatigue is caused by cyclic action, which may or may not be temperature related. Judging by your questions, you probably need expert help to avoid a potential diaster.