A tank that is 20 years old and has a bottom thickness of 0.170" with an original thickness of 0.250". What is the interval for the next internal inspection?

A tank that is 20 years old and has a bottom thickness of 0.170" with an original thickness of 0.250". What is the interval for the next internal inspection?

• A. 10 years
• B. 15 years
• C. 17.5 years
• D. 20 years

Answer: (C)

The next internal inspection interval for an aboveground storage tank is determined by several factors, including the age of the tank, the original metal thickness, and the current thickness as the tank ages due to corrosion and other factors. In this scenario, the tank is 20 years old with an original bottom thickness of 0.250 inches and a current bottom thickness of 0.170 inches. According to API 653 guidelines, one way to calculate the next inspection interval is to consider the service life and the degree of wall thickness loss. The remaining thickness can be compared to a minimal required thickness to ascertain how much life is left in the tank before it requires thorough internal inspection. The inspection interval is often based on a calculation associated with the rate of corrosion. For a tank that has lost a certain percentage of its original thickness, the intervals can be adjusted accordingly. This is typically done using techniques and formulas that analyze how much wall thickness has been lost and consider factors like the risk of leakage, safety and environmental impact, and operational factors associated with the tank's usage. In this specific case, the calculations likely point towards the recommended interval of 17.5 years, as it takes into account both the age of the tank and the percentage of thickness loss

The next internal inspection interval for an aboveground storage tank is determined by several factors, including the age of the tank, the original metal thickness, and the current thickness as the tank ages due to corrosion and other factors. In this scenario, the tank is 20 years old with an original bottom thickness of 0.250 inches and a current bottom thickness of 0.170 inches.

According to API 653 guidelines, one way to calculate the next inspection interval is to consider the service life and the degree of wall thickness loss. The remaining thickness can be compared to a minimal required thickness to ascertain how much life is left in the tank before it requires thorough internal inspection. The inspection interval is often based on a calculation associated with the rate of corrosion.

For a tank that has lost a certain percentage of its original thickness, the intervals can be adjusted accordingly. This is typically done using techniques and formulas that analyze how much wall thickness has been lost and consider factors like the risk of leakage, safety and environmental impact, and operational factors associated with the tank's usage.

In this specific case, the calculations likely point towards the recommended interval of 17.5 years, as it takes into account both the age of the tank and the percentage of thickness loss