🔍 Key Concepts

• Behavior of CO2 in low-pressure storage tanks as temperature rises when refrigeration is lost • Purpose of the relief valve on a low-pressure CO2 storage tank • Relationship between temperature, pressure, and CO2 phase (liquid/gas) in fire extinguishing systems

💭 Think About

• If the refrigeration fails and the tank warms, what happens to the pressure inside a tank of liquefied CO2? • Why would a relief valve need to open on a CO2 tank, and what would it discharge when it opens? • Which options describe something that would realistically continue over time as the tank stays warm, and which sound less physically likely?

✅ Before You Answer

• Check which option involves the relief valve and think about its role in protecting the tank from overpressure. • Verify which choices are consistent with CO2 changing from liquid to gas as temperature increases. • Eliminate any options that describe behavior that would violate basic fluid behavior (e.g., liquid flowing out a drain that is not designed as an overflow).