What is the minimum thickness of the bottom plate projection beyond the shell at the toe of the weld according to API 653?

What is the minimum thickness of the bottom plate projection beyond the shell at the toe of the weld according to API 653?

• A. 0.250"
• B. 0.100"
• C. 0.500"
• D. 0.010"

Answer: (B)

The standard outlined by API 653 specifies that the minimum thickness of the bottom plate projection beyond the shell at the toe of the weld should be 0.100 inches. This minimum thickness is essential to ensure the integrity of the weld and the connection between the bottom plate and the shell. Adequate thickness is critical in providing sufficient support and reducing the risk of corrosion and stress concentrations at the weld joint, which can lead to failure over time. This requirement ensures that there is enough material to withstand the stresses from the contents of the tank and helps in maintaining the overall structural integrity and safety of the tank system. In contrast, thicker projections, such as 0.250 inches or 0.500 inches, are not prescribed as the minimum because they could represent unnecessary excess that does not align with the specifications of API 653. A projection of 0.010 inches would be inadequate and would not provide sufficient material for a reliable weld connection, potentially leading to issues during the tank's operating life. The delineation of these standards relies on balancing structural integrity with efficient design requirements, making the 0.100-inch thickness the appropriate benchmark.

The standard outlined by API 653 specifies that the minimum thickness of the bottom plate projection beyond the shell at the toe of the weld should be 0.100 inches. This minimum thickness is essential to ensure the integrity of the weld and the connection between the bottom plate and the shell. Adequate thickness is critical in providing sufficient support and reducing the risk of corrosion and stress concentrations at the weld joint, which can lead to failure over time. This requirement ensures that there is enough material to withstand the stresses from the contents of the tank and helps in maintaining the overall structural integrity and safety of the tank system.

In contrast, thicker projections, such as 0.250 inches or 0.500 inches, are not prescribed as the minimum because they could represent unnecessary excess that does not align with the specifications of API 653. A projection of 0.010 inches would be inadequate and would not provide sufficient material for a reliable weld connection, potentially leading to issues during the tank's operating life. The delineation of these standards relies on balancing structural integrity with efficient design requirements, making the 0.100-inch thickness the appropriate benchmark.