CO2 fire extinguishers are widely used to tackle electrical and flammable liquid fires. One common question is how to determine the amount of CO2 left in the extinguisher since they do not have a pressure gauge. This post will detail the methods for checking the remaining CO2 in a fire extinguisher and explain why there is no gauge on CO2 extinguishers.
Why CO2 Fire
Extinguishers Don't Have a Gauge
Methods to Check How Much CO2 is Remaining
Since CO2 extinguishers do not have a pressure gauge,
alternative methods must be used to determine how much CO2 is left. The
following are the primary methods to check the remaining CO2:
1. Weighing the Extinguisher
Weighing is the most reliable and accurate method for checking the amount of CO2 remaining in a fire extinguisher. Here’s how to do it:
Step 1: Find the Full Weight of the Extinguisher
Each CO2 extinguisher has a label indicating its full weight when it is fully charged. This weight includes the cylinder, valve, and the full amount of CO2 gas. For example, the label might indicate that a fully charged 5 kg CO2 extinguisher weighs 10 kg (5 kg of CO2 and 5 kg for the cylinder and other components).
Step 2: Weigh the Extinguisher Using a Scale
Use a calibrated weighing scale to determine the current weight of the extinguisher. Place the extinguisher carefully on the scale to get an accurate reading.
Step 3: Calculate the Remaining CO2
Subtract the current weight of the
extinguisher from the full weight. The difference represents the amount of CO2
that has been discharged. For example, if the full weight is 10 kg and the
current weight is 8 kg, then 2 kg of CO2 has been used, leaving 3 kg remaining.
This method is straightforward and does not require specialized equipment, making it accessible for most users. It is also a requirement during regular servicing and maintenance checks by fire safety professionals.
2. Checking for Physical Signs of CO2 Usage
While less precise, certain physical indicators can suggest the amount of CO2 remaining in an extinguisher:
Feeling the Temperature of the Cylinder:
When a CO2 extinguisher is discharged, the cylinder becomes extremely cold due to the rapid release of compressed gas. If the extinguisher has been partially used, the cylinder may feel colder in certain areas. This method, however, is not very accurate and should not be solely relied upon for determining the extinguisher's status.
3. Using a Digital Weight Indicator (Advanced Method)
Some modern fire safety management practices employ digital scales or sensors integrated into extinguisher mounts to monitor their weight in real time. This technology provides immediate alerts if there is any reduction in the extinguisher’s weight, indicating CO2 usage or leakage. However, this method requires initial investment in equipment and is typically used in high-security or industrial environments.
4. Professional Servicing for Accurate Measurement
While weighing is a reliable method, it is also crucial to have CO2 extinguishers inspected regularly by certified fire safety professionals. During these inspections, professionals may perform a hydro static test, a safety measure that checks the cylinder's integrity and ensures no CO2 is leaking. Although this does not measure the exact amount of CO2 remaining, it ensures that the extinguisher is safe and reliable.
Conclusion
Determining how much CO2 is left in a fire extinguisher may seem challenging at first, but with the correct method such as weighing the extinguisher you can easily keep track of its status. Understanding these methods ensures that you are always prepared and that your fire safety equipment remains effective in emergencies.
By following these straightforward steps, you can easily understand how much CO2 is remaining in fire extinguisher.
