Which of the following is NOT an example of a pressure facility tank?

The correct answer identifies an underground storage tank as not being a type of pressure facility tank. Pressure facility tanks are specifically designed to handle and store fluids at certain pressure levels.

Above ground storage tanks, low-pressure tanks, and high-pressure tanks are all examples of tanks that operate at varying pressure levels—whether they are atmospheric, low, or high pressure. These tanks are constructed with materials and structural designs that can withstand the stresses caused by the internal pressure of the substances they carry.

In contrast, an underground storage tank is typically used for the storage of liquids like petroleum or hazardous substances without the requirement to manage internal pressure beyond atmospheric levels. Their primary function is to store products securely underground, minimizing the risk of exposure and environmental contamination. Therefore, while they are critical in the scope of hazardous materials, they do not belong to the category of pressure facility tanks.