What is Hydrostatic Testing of Fire Extinguishers?

Hydrostatic testing is an essential component of your facility’s fire safety maintenance program, but with a testing requirement of just once every 12 years, it can be difficult to stay on track. If it’s been some time since you’ve looked at your fire extinguisher’s service label, now might be a good time to check.

Before a fire extinguisher can undergo hydrostatic testing, it should first be inspected. We start with an inspection of the extinguisher’s exterior. Anything that could compromise the integrity of the cylinder, from corrosion to deep dents, means that the extinguisher cannot be safely tested, and should be removed from service.

What is Hydrostatic Testing of Fire Extinguishers?

Hydrostatic testing is completed on rechargeable fire extinguisher tanks to evaluate the cylinder’s ability to hold pressure. Hydrostatic testing checks for leaks and overall strength, and is completed to ensure the safety and effectiveness of a pressurized fire extinguisher.

How Often Do My Fire Extinguishers Need Hydrostatic Testing?

Hydrostatic testing is required for nearly any kind of rechargeable fire extinguisher, but the type of extinguisher you have will dictate how often hydrostatic testing is required.

In general, hydrostatic testing is required:

Every 5 years for pressurized water, carbon dioxide, and wet chemical fire extinguishers.

Every 12 years for dry chemical fire extinguishers.

The function of a hydrostatic test is to ensure that your fire extinguisher can still withstand its pressure rating. When a fire extinguisher undergoes hydrostatic testing, it is filled above its pressure rating with water.

At that point, the technician monitors the cylinder, looking for any drop in pressure. A drop in pressure during the hydrostatic test indicates that the fire extinguisher has a leak, and should be permanently removed from service. If a fire extinguisher fails the hydrostatic test, it cannot be put back into use.