Verifying Tank Integrity

An API 653 tank inspection is a critical step in repurposing a tank.  An API 653 inspection incorporates various non-destructive tests to evaluate the integrity of the tank’s floor, shell, and roof for fitness of service.  Depending on the age and condition of the tank, repairs may be necessary to bring the tank up to API 653 specifications.  Repairs may range from repairing weld and plate corrosion to jacking and leveling the tank to replacing the tank roof or floor.  In extreme cases, a tank may be so deteriorated that it would be more economical to dismantle the tank and build a new tank instead of performing repairs.  What is necessary to make the tank safe for operation depends on the condition of the tank discovered during the inspection.

The maximum fill height is another important piece of information from an API 653 inspection.  The maximum height calculation determines the amount of product that can be safely stored in the tank.  This calculation is based on the specific gravity of the product that will be stored in the tank [See Tank Calculator Page for examples of specific gravity for various products]. If the new product to be stored in the tank is heavier (having a higher specific gravity) than the product for which the tank was built, the maximum fill height will likely be lowered.

Internal Coating

Liquid products stored in a steel storage tank can have various degrees of corrosiveness.  An internal coating can prevent a steel tank from having a shorter lifespan due to storing a more corrosive product.  To determine whether an internal tank coating would be beneficial in your tank repurposing project, consult with a storage tank or coatings specialist.

Secondary Containment

Storing a different product can mean new regulations will apply to the use of the above ground storage tank. Depending on the product stored, federal and/or state regulatory rules may have secondary containment requirements.  These methods of preventing environmental contamination can be in several forms, such as a dike, double wall tank, or internal tank liner.  What satisfies secondary containment varies in every state, so it is important to know the exact containment requirements that would apply to the location of your above ground storage tank.


Still have questions on aspects of your tank repurposing project?  Call us at Heartland Tank Services, Inc., and we would be happy to guide you through the considerations necessary to successfully repurpose an above ground storage tank.  Contact us at 800-774-3230 or click here.