Which materials can be placed under the tank shell?

• A. Steel directly on concrete and ½ inch asphalt fiber board
• B. Wood blocks and crushed gravel
• C. Concrete and fiberglass
• D. Asphalt sheets and wooden pallets

Answer: (A)

The correct choice is that steel should be placed directly on concrete and ½ inch asphalt fiber board. This option is appropriate because using concrete provides a solid and durable substrate that can adequately support the weight of the tank and its contents. The inclusion of ½ inch asphalt fiber board serves as a compressible cushion that helps spread the load and minimizes localized stress on the tank shell. Additionally, this combination helps protect the steel from moisture that could cause corrosion, effectively extending the life of the tank.

Other materials mentioned in the other choices are either less stable or inappropriate for supporting the tank shell in the same effective manner. For example, wood blocks and crushed gravel may not provide a consistent support level, which is crucial for maintaining the integrity of the tank. Concrete and fiberglass could lead to compatibility issues, as fiberglass is not typically used in direct contact for structural support. Asphalt sheets and wooden pallets might not provide the necessary stability and durability required for the foundational support of a welded tank, particularly under heavy loads.