06/03/2026
Why CO₂ Fire Extinguisher Does Not Have Pressure Gauge?
✅ Definition
A CO₂ fire extinguisher is a type of extinguisher that uses carbon dioxide gas to put out fire, especially electrical and flammable liquid fires.
📘 Details
Unlike water or dry powder extinguishers, CO₂ is stored as liquid under very high pressure inside the cylinder.
The pressure inside remains almost constant until the CO₂ is nearly empty.
Because pressure does not change gradually, a gauge cannot show accurate remaining quantity.
That is why CO₂ extinguishers do not have pressure gauges.
Instead, we check them by weight during inspection.
This is explained in fire safety standards like Occupational Safety and Health Administration (OSHA) fire protection requirements.
🏗 Example
In an electrical room, if a CO₂ extinguisher looks full from outside, you cannot check pressure by gauge.
You must weigh it to confirm it is full.
