Iron & Steel Reservoirs, Tanks & Vats Over 300 Liters

The applicable standard depends on service conditions. Atmospheric storage tanks for petroleum products are typically built to API 650; pressure vessels must comply with ASME Section VIII; tanks for potable water may require NSF/ANSI 61 certification for coatings and materials. Foreign fabricators must demonstrate compliance with the relevant standard through documentation such as a manufacturer's data report (ASME Form U-1) or a third-party inspection certificate, which is reviewed by the facility's insurer and the authority having jurisdiction.

A tank imported fully assembled is classified as a complete article. Sections imported separately for field assembly may be classified as parts of tanks or as structural steel components depending on their form and the degree of fabrication. Presenting all sections as a single shipment with documentation identifying them as components of a specific tank assembly supports classification as an incomplete or unassembled article of the complete tank heading, which is generally preferable for duty and record-keeping purposes.