Principle of material selection for CO2 fire extinguisher valves

The pressure of liquid CO2 stored inside a CO2 fire extinguisher is usually between 55 and 70 bar at room temperature. Operation under high pressure places high demands on the strength and structural stability of the valve. Therefore, the valve material must have high strength to withstand the high pressure inside the fire extinguisher and is not prone to deformation or fatigue during long-term storage.
Brass is one of the most commonly used materials in CO2 fire extinguisher valves. Due to its high strength, wear resistance and good processing performance, it can effectively resist loss under high pressure. Brass performs well when subjected to high pressure, and its chemical properties are stable and not easy to oxidize.
Stainless steel is a higher strength material commonly used in industrial-grade CO2 fire extinguishers. Stainless steel can not only withstand higher working pressures, but also has excellent corrosion resistance, making it suitable for high-pressure and frequently used occasions.
When a CO2 fire extinguisher is used, liquid CO? quickly vaporizes and absorbs a lot of heat, and the temperature of the released gas can drop to -78.5°C. At such low temperatures, many materials will become cold and brittle, causing the materials to become fragile, brittle or fail. Valve materials must not only have good pressure resistance, but also be able to maintain toughness and structural stability at low temperatures.
Brass still maintains high toughness at low temperatures and will not brittle fracture due to drastic temperature changes, so it is an ideal material widely used in carbon dioxide fire extinguisher valves.
Stainless steel has better low-temperature toughness than brass, especially at extremely low temperatures. Its mechanical properties are stable and suitable for use in industrial or cold environments that require higher temperature adaptability.