API 650 storage tank cut-off valves

Large Low-Pressure Tanks Corrosion Allowance
In cases in which the rate of corrosion is closely predictable, additional metal thickness over and above that required for the initial operating conditions shall be provided and shall be at least equal to the expected corrosion loss during the desired life of the tank.
When corrosion effects are indeterminate before the tank is designed (although they are known to be inherent to some degree in the service for which the tank is to be used), and when corrosion is incidental, localized, or variable in rate and extent, the best judgement of the API 650 storage tank designer must be exercised in establishing reasonable maximum excess tank wall thicknesses. For all tanks that come under this classification, a minimum corrosion allowance of 1/16 in. shall be provided.

API 650 stipulates that an open tank should be provided with a wind-resistant ring to ensure that the API 650 storage tank 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.

The API 650 storage tank must go through strict inspection before putting into use. Inspection of plate groove of API 650 storage tank, vertical oil tank: After finishing the groove processing of oil tank plate, it is necessary to conduct dye penetrant inspection on the groove. This process is mainly aimed at the hard damage of groove in the machining process and the defects of the plate itself. If any defect is found, it shall be processed again until the defect disappears.