double-deck roof API standard 650 aboveground steel oil storage tanks

Natural ventilation loss: the main cause of natural ventilation loss is that the API standard 650 aboveground steel oil storage tanks is not tightly sealed. This is usually due to corrosion perforation on the top of the oil tank, or there is a height difference between the two orifices. The air tightness of the mixture in the API standard 650 aboveground steel oil storage tanks is higher than that of the air, which causes the mixture gas in the tank to be discharged into the atmosphere from the lower hole, and the external air flows into the tank from the high hole, resulting in natural ventilation loss.

API 620 crude oil tank piping materials made according to ASTM A333 and A350 may be used at API standard 650 aboveground steel oil storage tanks design metal temperatures no lower than the impact test temperature required by the ASTM specification for the applicable material grade without additional impact tests. For temperatures below those allowed by the ASTM specification, the following paragraph shall apply.

API 650 "welded storage tanks" API standard 650 aboveground steel oil storage tanks is a standard developed and issued by the American Petroleum Institute (API), which specifies the minimum requirements for the design, manufacture, installation and inspection of welded storage tanks.