180ft diameter API standard 650 petroleum storage tanks

Ultrasonic Examination of Butt-welds in Plates
Butt-welds in all tank wall courses subjected to a maximum actual operating membrane tensile stress, perpendicular to the welded joint, greater than 0.1 times the specified minimum tensile strength of the API standard 650 petroleum storage tanks plate material shall be completely examined.
Butt-welds in API 620 oil tank wall courses subjected to maximum actual operating membrane tensile stress, perpendicular to the welded joint, less than or equal to 0.1 times the specified minimum tensile strength of plate material shall be spot examined in accordance with Figure Q-2.

API 650 Tanks in which liquid fluids are stored and designed to withstand atmospheric pressure operation, less than 18 kPa, or internal pressures not exceeding the weight of the API standard 650 petroleum storage tanks roof, with temperatures no higher than 93, 3 C are included in the scope of this design code.

In order to ensure the safety of the vertical storage tank, API standard 650 petroleum storage tanks, the supplier should inspect the tank carefully before delivery. The failure of the tank body is mainly due to the weld and crack of the product. The inspection of API standard 650 petroleum storage tanks, vertical storage tank weld and microcrack is mainly to inspect the appearance forming quality of weld. The inspection contents include weld leg height, undercut, welding deformation, weld bead, arc pit, weld straightness, etc., as well as the internal quality of weld, such as slag inclusion, porosity, incomplete penetration, crack, incomplete fusion, etc.