What is the purpose of dimensional tolerances in tank construction according to API 650?

• A. To allow flexibility in design
• B. To ensure proper fit and effective performance
• C. To reduce material usage
• D. To comply with environmental regulations

Answer: (B)

The purpose of dimensional tolerances in tank construction according to API 650 is primarily to ensure proper fit and effective performance. Dimensional tolerances define the allowable variations in the dimensions of tank components, which is crucial in maintaining the structural integrity and functionality of the tank. Proper tolerances ensure that all parts fit together correctly, preventing issues such as leaks or structural failures that could arise from misalignments or improper fits. This allows for the safe storage of oil and other materials while supporting the overall performance objectives set by the design specifications and operational requirements. It's essential for tanks to meet these tolerances not only for safety reasons but also for efficient operation and compliance with industry standards.