As per ASME code, it is not mandatory to PWHT the PTC along with the equipment, code permits to simulate the pwht prior to PWHT of equipment. and it need not be the same cycle as PTC provided within the prescribed limitations given for heating rate, holding temp, holding time and cooling rate...
I fully agree with Priyasachin, besides even we do the same think. UT is not mandatory unless and until specifically asked by your client, for which u may charge.