Why is proper drainage significant in tank design according to API 650?

• A. To allow for easier cleaning
• B. To prevent water accumulation that could lead to corrosion
• C. To manage excess fuel
• D. To enhance the tank's appearance

Answer: (B)

Proper drainage is significant in tank design according to API 650 primarily because it helps in preventing water accumulation that could lead to corrosion. Tanks used for storing oil and other hydrocarbons are susceptible to the ingress of water, which can occur due to rain, condensation, or other factors. If water accumulates in the tank, especially at the bottom, it can create a favorable environment for corrosion.

Corrosion can not only deteriorate the integrity of the tank structure but also compromise the safety of the stored products. Water can create galvanic cells that accelerate corrosion processes, leading to pitting and other forms of structural damage. By ensuring proper drainage, design engineers can facilitate the removal of water, maintaining the tank's operational integrity and extending its service life.

While proper drainage may also assist in easier cleaning of the tank and contribute to the overall management of stored products, its primary role in preventing corrosion highlights its critical importance in the context of API 650 standards.