What is the minimum projection required from the toe of the shell-to-bottom fillet weld to the edge of bottom plates?

• A. 2 inches
• B. 3 inches
• C. ½ inch
• D. 1 inch

Answer: (C)

The minimum projection required from the toe of the shell-to-bottom fillet weld to the edge of bottom plates is established to ensure structural integrity and prevent potential failure or overstress in critical areas of a tank. According to API 650 standards, the correct projection minimizes the risk of weld-related defects and ensures an adequate bond between the shell and the bottom plates.

In this case, a projection of ½ inch is appropriate because it strikes a balance between providing sufficient overlap for structural strength and maintaining the required distance to minimize issues like corrosion or wear at the edges of the bottom plates. This projection is also closely aligned with industry practices, which recognize that excessive projections can lead to additional stresses or complications in the fabrication and maintenance of the tank.

Other options suggest larger projections, which, while they may offer more overlap, do not conform to the specific requirements set forth in API 650. Such excess could lead to unnecessary complications in the welding process and might not provide any additional benefit in structural performance, thus reflecting the importance of adherence to standardized measurements in engineering practices.