API standard 650 mechanically-anchored flat-bottom tanks in SUG III

The impact tests for API 620 welded storage tanks used pipe (including structural members made of pipe), bolting, and forgings, shall be in accordance with ASTM specifications ASTM A333 (seamless only) pipe, ASTM A36 Mod 1 plate, ASTM A131 Grades CS, D, and E steel plate, ASTM A633 Grade A CSA G40.21 Grades 38WT, 44WT and 50WT high-strength low-alloy structural steel plate, ASTM A350 carbon and low alloy steel forgings, and ASTM A320 Grade L7 bolts.

If additional requirements are met, higher internal pressures are allowed. API 650 only covers tanks that support the whole bottom evenly and API standard 650 mechanically-anchored flat-bottom tanks tanks in non-refrigerated service that have a maximum design temperature of 200 degrees F. It requires that you have a minimum material thickness of 3/16 inch.

Weld inspection of API standard 650 mechanically-anchored flat-bottom tanks, vertical oil tank wall plate: In the welding inspection process of oil tank wall plate, attention should be paid to the defects of thick wall plate, such as incomplete penetration, incomplete root fusion and cracks. If there is a root incomplete penetration defect, it is necessary to open the weld joint with carbon arc air gouging and grinding machine grinding, or even weld through, and then weld again after the defect is removed.