LPG storage vessels are typically designed according to which code?

• A. API 620
• B. ISO 9001
• C. ASME Section VIII Division 1
• D. ANSI B31.5

Answer: (C)

LPG storage vessels are pressure vessels, so they are designed under a formal containment code that governs how pressure, thickness, materials, fabrication, testing, and safety margins are handled. ASME B&PV Code, Section VIII Division 1 provides the specific rules for designing and constructing vessels that contain internal pressure, including how to calculate allowable stresses, determine wall thickness, apply corrosion allowances, reinforce nozzles, and specify welding, inspection, and hydrostatic testing requirements. It also covers the necessary fabrication controls and stamping so the vessel is recognized as meeting the standard for safe operation.

The other options don’t fit as the primary design standard for these vessels. API 620 and API 650 are focused on storage tanks, particularly bulk storage tanks, not the pressure-contained design typical of LPG vessels. ISO 9001 is a quality-management system standard, not a design code. ANSI B31.5 is a piping code, not a vessel design code. So the code that directly addresses the integrity and safety of pressure-containing LPG vessels is ASME Section VIII Division 1.