54m diameter API Std 650 welded tanks for oil storage

The API 620 large storage tank nozzle neck is fabricated by welding from 1/2-in. plate. The materials in the tank wall, the nozzle neck, and the reinforcing pad conform to ASTM A442 Grade 55. The main joints in the tank wall are fully radiographed, double-welded butt joints. The longitudinal joint in the nozzle neck is of the same type API Std 650 welded tanks for oil storage but is not radiographed; however, the longitudinal joint and all other parts of the nozzle-and-wall-plate assembly have been shop stress relieved after fabrication, as required by 5.25. The adequacy of the reinforcement and attachment welds shown in Figure F-6 shall be determined.

Under the same sealing effect, the internal API Std 650 welded tanks for oil storage floating roof API 650 tank can further reduce the evaporation loss compared with the external floating roof API 650 tank. This is due to the shielding of the fixed roof and the gas phase layer between the fixed roof and the inner floating plate, which has more significant heat insulation effect than the double disc floating roof of the API Std 650 welded tanks for oil storage external floating roof tank.

The foundation design of the API Std 650 welded tanks for oil storage should meet the requirements of foundation stability and deformation, that is, the API Std 650 welded tanks for oil storage foundation should not be crushed and the uneven settlement value of the foundation should be within the allowable range. The uneven settlement of the storage tank foundation should be specified in the design process of the safe allowable range, because excessive uneven settlement will reduce the safety of the API Std 650 welded tanks for oil storage and cause distortion and deformation of the tank wall and bottom plate.