Which of the following is NOT a primary type of fixed facility storage tank?

• A. Atmospheric
• B. Non-pressure
• C. Cryogenic
• D. Pressure

Answer: (C)

The main concept is how fixed facility storage tanks are categorized by the conditions under which they operate. Atmospheric storage tanks are unpressurized and vent to the atmosphere, handling liquids at or near ambient conditions. Non‑pressure tanks are designed to hold liquids without internal pressure above ambient, though they may have some vapor pressure and typical safety features for general service. Pressure tanks are built to contain liquids or vapors at pressures above atmospheric, requiring robust design and relief devices. Cryogenic tanks, while used to store extremely cold liquids, are a specialized class with insulation and very different design requirements, so they’re treated separately from the standard fixed facility storage tank types. Because of that specialized nature, cryogenic tanks are not considered a primary fixed facility storage tank type in this classification.