🔍 Key Concepts

• Requirements for fixed CO2 fire extinguishing systems on U.S. vessels in 46 CFR Subchapter J – Electrical Engineering and Subchapter I – Cargo and Miscellaneous Vessels (look especially at CO2 system design and cylinder room requirements) • How ambient temperature affects the pressure inside CO2 cylinders and the safety devices (relief valves, bursting discs) • Why regulations limit the maximum expected temperature in gas cylinder storage spaces for fire protection systems

💭 Think About

• Compare each temperature choice with what would be considered a typical warm machinery-space or tropical ambient temperature onboard a steel vessel • Think about which temperature would be high enough to significantly raise cylinder pressure and risk venting through safety devices, but still be a realistic design limit for an enclosed cylinder room • Ask yourself: does the regulation pick a very conservative number slightly above normal room temperature, or a much higher number closer to what you’d find near hot machinery?

✅ Before You Answer

• Verify in 46 CFR the exact wording for CO2 cylinder storage spaces and the phrase "anticipated ambient temperature in excess of" • Check which of the listed temperatures is commonly used in other marine regulations as a maximum design ambient temperature for equipment and stored pressure vessels • Confirm that the temperature you choose makes sense for a space that should be protected from direct machinery heat and sun, not a hot engine casing or weather deck