The API Standard 653 - Tank Inspection, Repair, Alteration, and Reconstruction provides guidance in the inspection, repair, alteration, and reconstruction of steel storage tanks used in the petroleum and chemical industries. The information contained in this Standard is based on the accumulated knowledge and experience of owners, operators, manufacturers, and repairers of steel storage tanks.

The rules given in this standard are minimum requirements. This standard is not to be interpreted as approving, recommending, or endorsing any specific design nor limiting the methods of inspection, repair, alteration or reconstruction. If tanks are inspected, repaired altered or reconstructed in accordance with this standard, the owner/operator may elect to modify, delete, or amplify sections of this standard. It is strongly recommended that such modifications, deletions, or amplifications be made by supplementing this standard rather than rewriting or incorporating sections into another complete standard. 254pp.