This Practice supplements API 650, Welded Steel Tanks for Oil Storage. Together, this Practice and API 650 provide requirements for the construction of atmospheric storage tanks.

This Practice and API 650 describe minimum construction requirements for the materials, design, fabrication, erection, examination, and testing of aboveground, non-refrigerated storage tanks. This Practice describes additions and modifications made to API 650. In addition, this Practice describes decisions made regarding options offered by API 650. This Practice supplements, but does not supersede, API 650 and any applicable jurisdictional requirements.

This Practice covers storage tanks that have design internal pressures of 17.2 kPa (2.5 psig) or less (see API 650, Annex F) and design temperatures less than 260°C (500°F) (see API 650, Annex M).

This Practice presumes the use of the API 650 Data Sheet to cover the requirements in API 650, and the Data Sheet, as a supplement, to define the additional requirements of this Practice.