API Std 650 anchored tanks leg sleeves

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 Std 650 anchored tanks 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.

The API Std 650 anchored tanks most widely used and most commonly used standard for global storage tank construction and procurement is API 650. The Chinese translation name is "AP1650 Steel Welded Petroleum Storage Tank". API 650 storage tank is for commonly used oil, gasoline, diesel, chemical and production water storage, etc.

Inspection of API Std 650 anchored tanks bottom: magnetic flux leakage scanning technology is used to detect the corrosion condition of API Std 650 anchored tanks bottom plate (such as corrosion depth and area, crack length, etc.). When there is a defect in the bottom plate of the API Std 650 anchored tanks, the magnetic field distribution will change and the sensor can detect it. The bottom of the oil tank should be free of foreign matters and dry during testing. Weld inspection of API Std 650 anchored tanks bottom plate: when vacuum leak test method is used to detect the tightness of oil tank bottom plate, soap water shall be applied to the weld and vacuum box shall be covered for observation.