API standard 650 flat-bottom steel tanks designed to operate under external pressure conditions

Deformation of the welding seam of the API standard 650 flat-bottom steel tanks is a common quality problem during the actual use of the API standard 650 flat-bottom steel tanks, which easily causes the tank body to leak and affects the safety of the oil storage tank. The welding seam deformation of the API standard 650 flat-bottom steel tanks is mainly caused by the lack of reserved welding seam gap and irregular operation. The oil storage tank has not reserved the corresponding weld gap, resulting in deeper root removal during the front welding activity. The heat output of the weld will increase under the influence of a long time, and the deformation of the weld will gradually become serious.

The Charpy V-notch test shall be used, and the minimum impact value at the design metal temperature shall be as given in Table R-2. For subsize specimen acceptance criteria, see ASTM A20. An impact test temperature lower than the design metal temperature may be used by the API 620 welded storage tanks Manufacturer, but in such a case the impact values at the test temperature must comply with Table R-2.

The welded API 650 tank in various sizes and capacities for internal pressures approximating atmospheric pressure (internal pressures not exceeding the weight of the roof plates), but a higher internal pressure API standard 650 flat-bottom steel tanks is permitted when additional requirements are met.