5454 aluminum plate API Std 650 cylindrical liquid-storage tank

Natural ventilation loss: the main cause of natural ventilation loss is that the API Std 650 cylindrical liquid-storage tank 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 Std 650 cylindrical liquid-storage tank 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.

The inner and outer tanks may be decoupled for seismic design of the tank and anchorage and assumed to act independently. However, if the inner and outer tanks API Std 650 cylindrical liquid-storage tank are supported by a common foundation, the seismic foundation loading shall be calculated using the lesser response modification values for either the inner tank or outer tank for both tanks and a dynamic analysis shall be performed to determine the combined effect.
Allowable Stresses: For Appendix R tanks, design allowable stresses shall be per API 620 large low pressure storage tank, Section R.3.3.

Before pressure test, the main drain hose system of API 650 petroleum storage tank floating roof should be thoroughly flushed. Provide blind flanges, gaskets and bolts required for the API Std 650 cylindrical liquid-storage tank test (other types of covers are also required if necessary). Covers for maintenance shall be provided in accordance with the interfaces specified by API 650 petroleum storage tanks, and these seals shall remain in place after the test; and for those interfaces that are not provided for maintenance covers, the covers can be removed after the API Std 650 cylindrical liquid-storage tank test.