Thanks for response, actually it is pressurise tank that is why I post here, however I have checked that based on allowable it is giving the range of 115 c with same allowable stresses, so can consider 100c as safe. But there is a limitation of pressure as at atmospheric pressure shell plates...
This is in regards with the design temperature and pressure of API 620 tank which are mentioned Design 80C and 0.5 bar(g)
what maximum temperature which can be operated at atmospheric pressure. please advice
material of construction is A240 316L