How are Freon bottles protected from excessively high temperatures and how can you tell that this has occurred?

• A. A thermal fuse triggers an audible alarm
• B. A pressure relief valve vents to atmosphere
• C. A fusible link prevents discharge until manual reset
• D. A thermal fuse (or blowout disk) will release the agent if the bottle temperature exceeds a certain limit, causing a red indicator disk to blow out

Answer: (D)

When Freon bottles get too hot, a temperature-activated device—often a fusible link or blowout disk—opens to vent the contents and prevent the cylinder from rupturing. This protection is tied to a specific temperature threshold, so the bottle safely releases gas before damage occurs. The red indicator disk is blown out as a visible sign that this protective release has happened, telling you that the bottle must be replaced or serviced.

Other options don’t fit because a simple audible alarm or a manual-reset device isn’t the standard protective action for high temperatures, and a pressure relief valve by itself isn’t the temperature-activated vent used to prevent overheat scenarios.