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

• A. Underground storage tank
• B. High-pressure horizontal tank
• C. Cryogenic liquid tank
• D. High-pressure spherical tank

Answer: (A)

Pressure facility tanks are built to hold substances under pressure or at very low temperatures, with designs that manage internal pressure and venting. Among the options, an underground storage tank is not a pressure facility tank because it is intended for storing liquids at near atmospheric pressure, usually for long-term bulk storage, and it’s not designed to withstand or regulate internal pressure like the other vessels.

The other types fit the idea of pressure vessels: a high-pressure horizontal tank is designed to store gases or liquids under significant pressure; a high-pressure spherical tank is shaped for strong, even stress distribution to handle high internal pressure; a cryogenic liquid tank stores extremely cold liquids and is engineered to maintain low temperatures and manage vapor pressure, which still requires a pressure-rated vessel design.

So the underground storage tank stands out as the non-pressurized storage option.