nitrogen technician inspecting a pipe for a nitrogen fire suppression system

We ran into a case where a company had a leaky dry fire suppression system. For months and months, they were continually repairing the leaks. However, when is the right time for a total system replacement? And what should the replacement be?

Today, we’ll look at a real-life project of someone who had a struggling dry fire suppression system, who after careful thought and analysis, was given the suggestion to convert to a nitrogen fire suppression system.

Let’s dive in:

Where the dry fire suppression system went wrong…

Back in 2002, dry fire systems were the norm. However, results indicating a flawed system are now coming afloat. The key reason? Dry fire systems simply rust from the inside out.

While the system is meant to be “dry”, they are filled with pressurized air, which will condensate when the temperature drops below the dew point. The result?

Condensation results in water leftovers, which, when reacted with oxygen and the steel pipe, results in rust. As more of the pipe begins to rust, tiny pinholes develop which leads to false fire alarms and repairs.

So, what are the possible solutions?

1) Continually repair the rust sections
2) Install a brand new dry fire suppression system
3) Convert the system to a nitrogen fire suppression system

After going through projected finances, installing a nitrogen fire suppression system was the preferred choice.

What’s so good about a nitrogen fire suppression system?

There is ONE main advantage a nitrogen system provides: Life expectancy.

The life expectancy of a dry fire suppression system is 12-15 years. Nitrogen fire suppression systems project a 60-75 year life expectancy. That’s a 5x increase in life expectancy!

Nitrogen does not cause rusting in the presence of steel. Also, the water will not condense in normal temperate conditions.

Potter Electric Signal Company did a study on corrosion over a 12 month period using 98% nitrogen vs compressed air:

metal loss of corrosion of 98% nitrogen vs compressed air

We can see very clearly that the 98% Nitrogen gas corrodes metal considerably less than compressed air.

How can I get started converting to a Nitrogen system?

Most won’t consider converting until it’s the appropriate time. If a dry fire suppression system (that uses compressed air) lasts 12-15 years, then any system installed from 2004-2007 should be at the end of its life cycle.

The first step any institution should take is to call your fire protection company who installed your initial system. They will inspect your current system, tell you have much life is left, and then provide you options to maintain your system for the future.

Sometimes repairs in a fire suppression system are worth it, sometimes they’re not. In the case above, when testing the system, there were five different leaks…some very extreme. Also, there were several false alarms triggered due to air leakage.

The decision to replace your fire system should be influenced by careful insight and testing done by a professional fire protection company.