Inspection and evaluation requirements for portable containers, shop-fabricated tanks, and field-erected tanks with a maximum capacity of 75,000 gallons are provided by the Steel Tank Institute (STI STD SP001). Aboveground storage tanks must undergo STI-SP001 examinations to assess their suitability for continuing service (ASTs). Inspections are carried out to determine the state of the ASTs and any changes. Tank inspections described by this standard are used to detect degradation of tanks and appurtenances, ensure compliance with 40 CFR 112, and ensure proper installation of systems according to manufacturer's recommendations and industry norms.