Depending on the type of substance stored in the tank, ASTs may be regulated by the federal or state government. Even if an above ground storage tank is not regulated by law, the American Petroleum Institute (API) provides standards that provide guidance as to sound engineering for the manufacturing, use, maintenance, and inspection of these tanks. The main API specifications that are the recognized standard for large field-welded steel ASTs are API 650 for construction and API 653 for tank inspection.

API 650 is the internally recognized standard for the construction and maintenance of AST units. The API Specifications address the required thickness of each piece of steel based on the size of the tank being built as well as the welding requirements. API 650 also addresses how best a tank can be constructed to withstand natural conditions such as earthquakes and high winds.

API 653 is the standard for the inspection and repair of ASTs as built to the API 650 standard. Most states require regular inspections of ASTs to ensure their integrity to safely hold the contents. Various industries also have their recommendations for periodic inspections based on the fluid being stored. The Fertilizer Institute recommends that all liquid fertilizer tanks be inspected at least every 5 years.

For more information about above ground storage tanks such as liquid fertilizer tanks and others, feel free to leave a comment or question at the bottom.