ASME Section VIII Division 1 applies to pressure vessels operating above which threshold?

• A. Below 15 psig
• B. Above 15 psig
• C. Above 100 psig
• D. All pressures

Answer: (B)

The key idea is that ASME Section VIII Division 1 governs vessels designed to operate at higher pressures, using the fuller set of requirements for design, materials, fabrication, testing, and inspection. The threshold used is 15 psig (gauge). Vessels operating above 15 psig fall under Division 1 because the higher pressures require the more robust design rules, calculations, and quality controls encapsulated in this division. If a vessel operates at or below 15 psig, the code treatment is typically much less stringent, reflecting the lower risk, so Division 1 is not applied for those cases. Therefore, Division 1 applies to pressure vessels operating above 15 psig.