Direct buried transformer tanks are commonly constructed of which materials?

The choice of materials for direct buried transformer tanks is crucial for ensuring durability, safety, and functionality. Metal or polyester with a metallic liner is the correct answer because these materials offer strong resistance to corrosion and environmental challenges when buried underground. Metal containers, often made of steel or aluminum, provide both structural integrity and protection against external pressures, while the polyester lining can offer additional resistance to moisture and chemical exposure.

Using metal ensures that the tank can withstand the mechanical stresses of being buried. Additionally, the metallic liner helps in maintaining insulation and preventing electrical faults, which is particularly important in transformer applications. This combination of materials also aligns with industry standards for safety and reliability in electrical installations.

Other materials like wood, fiberglass, copper, aluminum, brick, or concrete do not provide the same level of durability or protective qualities necessary for long-term underground applications, which is why they are not the preferred choices for constructing direct buried transformer tanks.