Fatigue Calculation for Pressure Vessels

Hi, I want to perform fatigue calculations on a pressure vessel (cylinder+ heads+ nozzles) according to ASME Sec Viii. I have pressure fluctuations and number of cycles expected per hour and all other relevant design data. i have done this for nozzles only in PV Elite and Compress but now i am clusless about cylinder and heads. Since this is first time that our client has demanded this. Kindly guide me in this respect. Even manual equations and calculations will work. Plz reply. Regards