What is the function of the pressure gauge on a fire extinguisher?

The pressure gauge on a fire extinguisher is a crucial safety indicator used to display the gas pressure within the extinguisher. Its function is to help users determine if the fire extinguisher is in normal working order and to ensure its effective use when needed.

1. Functions of the Pressure Gauge on a Fire Extinguisher

(1) Indicating Exhaust Pressure

The pressure gauge displays the gas pressure inside the fire extinguisher, ensuring it is in the correct working condition. If the pressure is too low, it means there is insufficient compressed gas, which may prevent effective extinguishing and thus affect the fire extinguishing effect. By observing the pressure gauge, users can quickly confirm whether the fire extinguisher is adequately pressurized, preventing failure in emergencies.

(2) Facilitating Regular Inspections

The pressure gauge provides a simple and intuitive basis for regular fire extinguisher inspections. Regularly checking the fire extinguisher's pressure helps determine if it needs refilling or maintenance. Generally, fire extinguishers should be inspected annually, and the pressure gauge helps inspectors quickly determine if the pressure is within the normal range.

(3) Indicating Expiration Date of Fire Extinguisher

During long-term storage, fire extinguishers may be affected by factors such as temperature changes and frequency of use, leading to changes in internal gas pressure. Checking the pressure gauge to ensure it is within the normal range helps users determine if the fire extinguisher is ineffective or expired, allowing for timely replacement or refilling.

(4) Risks of Low or High Pressure

Low Pressure: If the pressure gauge indicates a pressure below the normal range, it may signal internal gas leakage or damage to the fire extinguisher, potentially causing it to malfunction. It should be checked or refilled promptly.
High Pressure: If the pressure gauge indicates a pressure that is too high, it may cause the fire extinguisher's pressure to exceed the safe range, posing an explosion risk. This may be due to prolonged exposure to high temperatures or other abnormal conditions, requiring prompt professional inspection and handling.

(5) Normal Pressure Range Indication

Generally, the pressure gauge on a fire extinguisher usually has an indication area, including:
Green Area: Indicates the fire extinguisher's pressure is within the normal range, allowing for safe and effective use.
Red Area: Indicates either low or high pressure, requiring inspection or maintenance. Low pressure: Indicates insufficient gas inside the fire extinguisher, which may prevent it from functioning properly.
High pressure: Indicates excessively high internal pressure in the fire extinguisher, which may pose a safety hazard.

2. How to check fire extinguisher pressure gauge?

(1) Check the pressure gauge pointer position

Normal range: Check if the pressure gauge pointer is in the green zone. If the pointer is in the green zone, the fire extinguisher pressure is normal and it can continue to be used.
Low pressure: If the pointer is in the low-pressure section of the red zone (usually marked "LOW" or similar), it indicates insufficient gas inside the fire extinguisher, which may require refilling or repair.

High pressure: If the pointer is in the high-pressure section of the red zone (usually marked "HIGH" or similar), it indicates excessive pressure inside the fire extinguisher. This may be due to a high-temperature environment or equipment malfunction, and should be checked and addressed promptly.

(2) Check for external damage to the fire extinguisher

In addition to checking the pressure gauge, pay attention to whether the fire extinguisher itself has obvious external damage, dents, or leaks. Visual inspection helps to identify potential damage or gas leaks. During inspection, check the fire extinguisher's casing, valves, nozzles, etc., to ensure there is no corrosion or other damage that may affect its use.

(3) Confirm that the pressure gauge is working properly

Sometimes, the pressure gauge itself may not display the pressure accurately due to aging or damage. If you suspect the pressure gauge is inaccurate, contact a professional for calibration or replacement. Ensure the pressure gauge accurately reflects the gas pressure inside the fire extinguisher.

(4) Regular Inspection and Maintenance

Fire extinguishers require regular inspection to ensure they are in good working order. It is recommended to check the pressure gauge monthly, especially during hot summers or cold winters, as temperature changes can affect the pressure of the gas inside the extinguisher.

Regularly checking the fire extinguisher pressure gauge ensures it functions properly when needed, preventing it from becoming unusable in emergencies due to abnormal pressure. By checking if the pressure gauge pointer is within the normal range, inspecting the extinguisher's appearance and refill date, and promptly addressing any abnormalities, you can effectively extend the extinguisher's lifespan and maintain its reliability.