One more question...
I have take a corrosion allowance of 3 mm for shell / heads and 1.5 mm for the nozzles (as is said in the Heat Exchange Institute Standard for Deaerators).
In the calculation of the values of UG-16(b), UG-45(b)(1) and UG-45(b)(2), which value of CA shall be use, 3 or 1.5...