Which of the following is not considered a part of the tank?

The correct choice indicates that a structural beam is not considered a part of the tank itself. In the context of tank construction, the tank typically consists of components that are critical for holding and containing the fluid, which would include the tank shell, the tank lid, and the tank bolts.

The tank shell forms the main body that holds the liquid, while the tank lid provides a secure closure at the top, preventing contamination and loss of the substance inside. Tank bolts are essential for securing various components of the tank together, ensuring structural integrity and preventing leaks.

In contrast, a structural beam is generally viewed as part of the surrounding support infrastructure rather than a component of the tank. Its role is to support the tank rather than hold or contain materials, which is why it is not classified as part of the tank assembly. This distinction helps clarify the tank's primary components that directly interact with the contents it stores or contains.