API Std 650 aboveground oil storage tanks overturning stability

When as-rolled plate material complies with impact test requirements as specified here, the material need not be normalized. If, as with ASTM A516, the specification prohibits impact test without normalizing but otherwise permits as-rolled plates, the API 620 welded storage tanks material may be ordered in accordance with the above provision and identified as “MOD” for this API modification.

API 650 internal floating roof oil tank executive standard: domestic design standard: GB50341-2003 "Vertical cylindrical steel welded oil tank design code"; domestic construction standard: GB50128-2005 "vertical cylindrical steel welded oil tank" Construction and Acceptance Specification; API Std 650 aboveground oil storage tanks Foreign design standard: API650-2007 "Standard for Welded Steel Petroleum Storage Tanks."

Static storage loss is also known as "small breathing" consumption. The rise and fall of the temperature in the API Std 650 aboveground oil storage tanks leads to the increase and decrease of the pressure in the tank, which makes the mixed oil gas discharged from the tank, and the external air is sucked into the tank, resulting in the oil consumption. Fluid level loss is also called "big breathing" loss. It is the oil consumption caused by the change of gas space volume in the API Std 650 aboveground oil storage tanks during the oil receiving and sending operation, which causes the mixed oil gas to be discharged out of the tank, and the external air is sucked into the tank, resulting in the oil consumption due to the change of liquid level height.