What distinguishes a double-bottom tank as defined in API 650?

• A. A single layer of protection against leaks
• B. Two bottoms for enhanced leak protection
• C. A tank shape that minimizes structural stress
• D. A design focused on aesthetic appeal

Answer: (B)

A double-bottom tank, as defined in API 650, is specifically designed with two layers of bottom construction, which serves a critical purpose of enhanced leak protection. This design feature allows for the detection of potential leaks between the two bottoms, providing an additional layer of security against environmental contamination and loss of product.

This configuration is particularly beneficial for the storage of hazardous liquids, as it minimizes the risk of leaks that can lead to spills, environmental damage, and safety hazards. The presence of an interstitial space between the two bottoms can also facilitate monitoring and maintenance practices, further increasing operational safety and regulatory compliance.

Other options, while potentially relevant in various contexts, do not accurately define the primary distinguishing feature of a double-bottom tank as specified by API 650. The emphasis is solely on the protective aspect, ensuring that the tank can withstand potential leaks more effectively than single-bottom tanks.