The 'U' stamp signifies construction under which ASME division?

• A. Section VIII Div.1
• B. Section VIII Div.2
• C. Section IX
• D. B31.3

Answer: (A)

The U mark is the ASME Certification for unfired pressure vessels, showing the vessel was built to the rules in Section VIII, Division 1. This division covers the general design, materials, fabrication, examination, and testing requirements for unfired pressure vessels, so a U stamp confirms compliance with those specific standards. Division 2 uses a different stamp (U2) for vessels built to its alternate rules, while Section IX deals with welding qualifications and is not the stamping used to certify vessel construction, and B31.3 is a piping code, not the vessel stamping. So the U stamp indicating construction under Section VIII, Division 1 is the correct association.