Is it Mandatory to do PWHT if the vessel is in Cyclic Service?

Could you please provide the reference which can justify this requirement.

PWHT might be required for cyclic service, when demanded in Project specifications issued by Project Consultant (EPC) or from the Process Licensor.
As far as ASME CODE, i have not seen any mandatory requirement of PWHT in case of Cyclic service. Somebody correct me if i am wrong.

Hello mihir11

You might possibly be thinking of shakedown, which does tend to stress relieve. However, ASME VIII, Division 1 and Division 2 do not consider this. The codes generally consider cyclic loading with fatigue (crack growth) only.