Question: Is it required to postweld heat treat a fabricated pressure vessel in clad steel, base metal of ASTM A285 Grade C (21 mm thick) and cladding of ASTM A240 Grade TP405 (2.78 mm thick) under the rules of UCL-34, Section VIII, Division 1?
Reply: It is preferred that material be ordered, produced, and documented to an ASME material specification under Section II of the Code. No postweld heat treatment need be performed due to the fact that the material is below the minimum size limitation for P-No. 1 material as listed in Table UCS-56 of Section VIII, Division 1, provided the electrode used is either austenitic or nonair hardening nickel-chromium-iron electrode. [See UCL-34(b)].