What is the required projection when ordering bottom plates or annular plates?

• A. At least 2 inches past the shell
• B. 1 inch from the weld
• C. 1.5 inches past the shell
• D. At least flush with the shell

Answer: (A)

When ordering bottom plates or annular plates for tanks according to API 650 standards, the requirement is for the plates to project at least 2 inches past the shell. This projection is essential to ensure proper welding and structural integrity at the connection points between the bottom plates and the shell of the tank. This excess material allows for adequate overlap during the welding process, which contributes to the overall strength of the tank structure and helps prevent potential leaks or failures at the joint.

The requirement for a minimum projection also takes into account the need for proper fitting during assembly, ensuring that any variations or tolerances in fabrication do not compromise the quality of the welded joint. In essence, this projection is a safety and performance consideration that is crucial for the long-term functionality of welded storage tanks as outlined in API 650 guidelines.