Dispelling common myths about nitrogen generators

There is a growing emphasis on the construction of new data centers and cold storage warehouses across the Middle East, and corrosion has long been the enemy of the dry and preaction sprinkler systems that protect these spaces. Nitrogen as a supervisory gas was once considered an innovative way to reduce corrosion but has now become commonplace across the US and Europe. However, some in the region still have questions. Clearing up some common myths surrounding the use of nitrogen generators to combat corrosion will help further diminish the threat that corrosion presents in fire sprinkler systems everywhere.

The use of Nitrogen in fire sprinkler systems has risen dramatically over the past decade with positive results. However, the process and products used to generate and deliver nitrogen can sometimes be cause for some apprehension. Having concerns is certainly not unusual when a new technology disrupts a long-standing traditional method. But whether you regard it as due diligence, or genuine skepticism, the myths that exist need to be addressed. These conversations are all part of the process and help to produce a better end-result.

The science behind nitrogen and its benefits in fire protection systems is simple. Nitrogen is a very stable inert gas when used in sprinkler systems. The term “inert” refers to its resistance or inability to react to what it encounters. Conditions are perfect for corrosion to occur inside the piping of a typical dry or reaction sprinkler system. Just like the fire triangle which requires heat, fuel and oxygen to support combustion, corrosion needs three things as well: iron, oxygen, and water. Simply put, oxygen present inside the system reacts readily with the iron in the pipe, while the water helps the process occur. Once that process begins, corrosion thrives. But when the oxygen present in the air inside the piping is replaced with an inert gas like nitrogen, the corrosion process can’t be supported any longer.

The concept may be simple, but the process of producing nitrogen and getting it into a sprinkler system could seem intimidating to some. The application of the technology is what often raises questions. However, time, research, and real-world experience have provided answers to many of these questions. Below are five of the most common myths and misunderstandings that occur, along with information to help put these fears to rest.

Myth – Nitrogen use is hazardous.

Response – Concerns about safety are always taken seriously. But in this case, there’s nothing to worry about. There are usually two aspects regarding safety and nitrogen use, and both deserve attention.

The first involves the safety of those working on or around the nitrogen generator and/or the sprinkler system using nitrogen. From a pure toxicity perspective, the answer is easy – nitrogen gas is non-toxic. And that’s a good thing since the air we breathe on Earth is made up of about 78% nitrogen. Like other inert, but non-toxic gasses, the risk lies in the potential for oxygen depletion if nitrogen is released in large enough quantities in a confined space. This is highly unlikely with the low volumes and pressures that nitrogen generators produce. Basic precautions such as ensuring adequate ventilation are typically recommended by manufacturers.

Often the hazards considered to be associated with nitrogen are a result of past experiences with compressed nitrogen in bottles or from liquid nitrogen. Compressed nitrogen comes with the same risk as any high pressure cylinder. They must be secured against tipping and other physical damage to prevent a catastrophic “launching” of the cylinder itself. Liquid nitrogen is extremely cold, with a boiling point of-196°C (-320°F). Because of that low temperature, nitrogen from a liquid source tends to settle into low areas, potentially increasing the asphyxiation risk. Neither of these hazards are present with the use of nitrogen generators.

The second piece of this myth involves the flammability of nitrogen. Obviously, any material used in conjunction with a fire protection system must not worsen the fire it was designed to control. And that is certainly the case with nitrogen. In fact, nitrogen is used in many systems, including aircraft fuel systems, to reduce the risk of fire. The same characteristics that make it valuable for the prevention of corrosion – its ability to displace oxygen – also make is useful in preventing fires.

Myth – Nitrogen generators are expensive, especially compared to traditional air compressors.

Response – Cost is always a concern, but when the benefits of nitrogen generators are weighed, their overwhelming value becomes apparent.

There’s no doubt that the up-front cost of a nitrogen generator as compared to an off the shelf air compressor is higher. But that’s not an even comparison. Now that nitrogen generator technology has existed for an extended period, and we have been able to witness first-hand the value of replacing the corrosive oxygen with an inert gas in sprinkler systems, we are able to quantify these money savings to address this myth.

Value means something different to everyone. If you ask a facility manager what brings them value in terms of their fire protection systems, they will likely respond with increased reliability and decreased maintenance issues. Both areas are where nitrogen generators are an asset. Water delivery time is an important factor in the success of a dry or preaction sprinkler system in terms of suppressing a fire, and corrosion inside the pipe slows that water delivery, and in some instances, can completely block it. A study by NFPA in 2014 revealed that, although sprinkler systems are very reliable overall (about 96% of the time), when they activate but fail to control the fire, 18% of those cases are due to not enough water being released. Corrosion inside the pipe is certainly a factor in many of these instances.

Sprinkler system maintenance another big concern that facility managers have. Of all building systems, maintenance issues with sprinkler systems, especially

by Jason Webb