ASTM A181 forgings API standard 650 aboveground welded storage tanks

When roof plates, knuckle plates, compression rings, and manways and nozzles including reinforcement are primarily subjected to atmospheric temperature, the rules in API 620 oil tank standard Q.2.3 shall govern.
Large Welded storage tanks Secondary Components
In general, secondary components include those components that will not be stressed to a significant level by the refrigerated liquid, those whose failure will not result in leakage of the liquid being stored, those exposed to product vapors, and those that have a design metal temperature of –60°F or higher.

API 650 stipulates that an open tank should be provided with a wind-resistant ring to ensure that the API standard 650 aboveground welded storage tanks tank body maintains its roundness when subjected to wind. There are no hard and fast rules for vault API 650 storage tanks. It can be determined by comparing the equivalent wall height with the maximum height of the unreinforced tank wall.

Tank cracks are common API standard 650 aboveground welded storage tanks defects, mainly including tank wall cracks, internal cracks, weld zone cracks. The reason for these defects may be that the defects not exceeding the standard existed in the early stage of API standard 650 aboveground welded storage tanks construction, which become obvious after the later use. Or in the process of using the API standard 650 aboveground welded storage tanks, the tank body material generated new defects due to corrosion, pressure, wear and other reasons, and tank cracks.