If you have a water sprinkler system protecting your facility, the larger concerns you have about your system probably revolve around corrosion and leaks. Corrosion, often found in steel pipes, can lead to pinhole leaks, gunk build-up, and slow water movement. Leaks, usually a result of freezing temperatures, corrosion, or sprinkler damage, can quickly destroy the property that a system is designed to protect. In the video below, watch as fire protection expert Lee Kaiser shares insight on why corrosion and leaks occur, and what you can do to prevent them from happening with your system.
Lee: "A growing problem: FM Global gives us some data. The fifth leading cause of leakage failures in systems, 40 percent of those corrosion cases involve the presence of microbial influenced corrosion. Basically, there's little bio-bugs in the pipe. If they're present then they make the corrosion worse and decrease the time it takes for a system to fail. A failing system can cause pinhole leaks, which can cause property and equipment damage. That picture with the leak streaming down, that recently happened at a site that we service. It was a telecom site, had a pinhole leak, sprayed on the switch, the switch was shut down and communications, 911, the whole works for about 18 hours.
It wasn't a huge building. It didn't serve a big chunk of the population, but it happened because of a sprinkler leak. The repairs to chase all these leaks are very costly, including cleaning the pipes which can lead to possible system replacement.
The nursing home example is exactly that. They had to replace the system because it was so full of corrosion and it would no longer flow water. This can render the system inoperable and increase the gunk and corrosion inside the pipe, which leads to increased friction loss so that water is delivered slower to the sprinklers. It can also dislodge that stuff and block sprinkler heads, and then certain gaskets and systems can deteriorate because of corrosion and cause leaks.
Unintentional Introducing Oxygen Into Your System
Audience: "What is the deal with opening up your pipe and flushing out your sprinkler lines? Sometimes you're introducing more oxygen, which accelerates the corrosion issue. What's your theory? Any thoughts on that?"
Lee: "Okay, here's what's required. Let's pick a dry pipe system. We have to do an internal inspection of the valve and then every five years we have to do a trip test. Go to a pre-action system and we have to do a partial flow trip test every year, which introduces some water and some fresh oxygen into the system. But, we don't have to take water all the way from the valve to the inspector's test station.
Every three years we have to do that full flow trip test for pre-action systems and that definitely puts new water and new oxygen into the system. The intent is that we pitch our pipes, we have low point drains, and we do our best to dry it out.
Except that doesn't necessarily happen, which brings us to another solution as far as replacing the air in the pipes with compressed nitrogen. We're gonna talk about that in just a couple slides for nitrogen generators. We will also talk about replacing the compressed air with compressed nitrogen, which does not support corrosion.
Why Does Corrosion Happen?
The reason we have corrosion is we have this corrosion triangle that exists inside of steel pipes. We have metal, water, and oxygen. When those three things are present, things are going to corrode, but just like the fire triangle, remove any one and then it can't exist, so let's step through those.
Can we remove the metal out of the pipes? Well, there's CPVC pipe out there but they're only good to a certain size. I think we only use them to around an inch and a half in diameter at maximum. Beyond that, we hop over to steel pipe. So we're not really gonna get rid of that pipe size in our system so we're always going to have a steel pipe.
We could remove all the water. Low point drains, pitch the pipes, but we still don't always get all the water out. It's just typically impossible to do that. Our systems are based on water so we can't really get rid of that.
The final option would be to remove the oxygen. That oxygen is in the compressed air and that's where the industry has chosen to focus."
Thank you for watching this educational video on corrosion and leaks within a fire sprinkler system. To learn more about other topics in fire protection, subscribe to our blog, attend one of our seminars or webinars, or watch other videos in this series using the index below.
Problem 1: How to Operate Your Fire Panel
- How to Operate Your Fire Panel: Alarm Signals
- How to Operate Your Fire Panel: Trouble and Supervisory Signals
- How to Operate Your Fire Panel: Conventional and Addressable Panels
Problem 2: Causes and Cures for Trouble Signals
Problem 3: Failure to Detect a Fire
- Failure to Detect a Fire: Common Causes
- Failure to Detect a Fire: Minimum Requirements and Performance Design
Problem 4: Causes and Cures for False Fire Alarms
Problem 5: Accidental System Discharges
- Accidental System Discharges: Dirty Environments and Human Error
- Accidental System Discharges: Training, Malfunctions, and Non-Discharge
Problem 6: Fire Sprinkler Leaks and Corrosion