API 650 cylindrical liquid-storage tank fittings and attachments

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 650 cylindrical liquid-storage tank 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.

This standard applies only to API 650 tank API 650 cylindrical liquid-storage tank whose entire bottom is uniformly supported and to API 650 tank in non-refrigerated service that have a maximum design temperature of 93°C (200 °F) or less.

Due to the volatility of oil products, the volatile consumption of oil products is inevitable in the storage process of large oil storage tanks such as API 650 cylindrical liquid-storage tank. The volatilization of oil causes economic losses and pollution to the environment. Especially in the open air environment, large-scale oil storage tanks in the petrochemical industry will continue to accumulate energy when exposed to the sun, causing their surface and interior to heat up rapidly, causing sun overheating, and accelerating the volatilization of oil. How to effectively reduce the volatile consumption of large oil storage tanks?