How are fire extinguishers winterized?

How are fire extinguishers winterized?

• A. Replacing with foam
• B. Heating to high temperature
• C. Adding 15 percent nitrogen to CO2
• D. Replacing with water-based extinguishers

Answer: (C)

When extinguishers are used in cold weather, the behavior of the stored CO2 can change, making discharge less reliable and increasing the chance of icing or flow issues. The best way to keep performance consistent in winter is to modify the gas mixture so the discharge remains stable as temperatures drop. Adding a small amount of nitrogen to the CO2 creates an inert diluent that smooths the expansion and helps maintain the right flow and pressure when it’s cold. About 15% nitrogen is used because it provides enough diluent to improve discharge characteristics without significantly reducing the extinguishing power of the CO2. This approach keeps the extinguisher effective in winter, whereas replacing the agent with foam or water, or heating the cylinder, would alter safety and operation in inappropriate ways.

When extinguishers are used in cold weather, the behavior of the stored CO2 can change, making discharge less reliable and increasing the chance of icing or flow issues. The best way to keep performance consistent in winter is to modify the gas mixture so the discharge remains stable as temperatures drop. Adding a small amount of nitrogen to the CO2 creates an inert diluent that smooths the expansion and helps maintain the right flow and pressure when it’s cold. About 15% nitrogen is used because it provides enough diluent to improve discharge characteristics without significantly reducing the extinguishing power of the CO2. This approach keeps the extinguisher effective in winter, whereas replacing the agent with foam or water, or heating the cylinder, would alter safety and operation in inappropriate ways.