What role does design stress play in tank construction according to API 650?

• A. It is not considered in the design process.
• B. It helps determine wall thickness for safety.
• C. It mainly addresses aesthetic factors.
• D. It applies solely to non-welding materials.

Answer: (B)

Design stress is crucial in tank construction according to API 650, as it helps determine the appropriate wall thickness for safety. This concept is fundamentally tied to the structural integrity of the tank, ensuring that it can withstand various loads, including internal pressures, external forces, and environmental conditions. By calculating design stress, engineers establish a threshold that the materials used must meet or exceed, thus preventing failures that could lead to catastrophic events such as leaks or collapses.

This process involves various safety factors and material properties to ensure that tanks are designed to operate reliably over their intended lifespan. In summary, design stress serves as a guiding principle for engineers to create a robust and safe storage environment for liquids, aligning with the standards outlined in API 650.