Not all fire suppression systems have mandatory NFPA 12 requirements that have to be applied retroactively. Carbon dioxide (CO2) systems are one of the few, and they cannot be grandfathered in. Since 2008, NFPA 12 has added requirements like discharge delays, odorizers, lock-out valves and other equipment and signage. In this video, fire protection expert Lee Kaiser explains some of these mandatory features and upgrades that will make your fire suppression system safer.
CO2 Systems: Safety Upgrades, Designs, and Applications
Lee: "So the safety upgrades that I mentioned, in the 2008 edition of NFPA 12, the code-making committee for gaseous suppression systems realized that we're still killing too many people with CO2 discharges, and so they added a number of things to the code and made them now mandatory. So this is only one of the few mandatory requirements that I know about that's done in fire codes. Most of the time it's an improvement of the code and any new system has to follow it, but this is actually retroactive. So if you have an existing CO2 system, you have to go back and upgrade your system to meet these safety requirements, including adding lock-out valves. So on the discharge piping from the cylinders, you need to have a valve in the line that you can close and then lock out and tag out when you go into that occupied space, or normally unoccupied space if it's total flood and work in that environment.
NFPA 12 Mandatory Requirements
Discharge delays. These are mechanical delays that will give you some time to exit the space so that you can hear this other device, a mechanical pneumatic siren, so a siren that's run by the gas pressure that warns people inside that space that they need to exit and that that discharge delay will be done soon, and the gas will be coming into there.
Odorizers. Now, this is important. There's a good way to teach this for CO2. CO2 is odorless and colorless, so you can't see it necessarily coming into the space or know that it's there, so we add odorizers to a system to make them safer, and that's a mechanical device that injects a little bit of oil of wintergreen, so a mint smell, to the CO2 so you can smell it. You should be trained, if you work in that space, when you smell a mint smell, which is probably not common in the space that you're working, when you smell that mint smell you know to get out. If you don't get out, you're going to die a very minty death. So we don't want that to happen to anybody.
And then other equipment and signage. Those are some of the things.
Compliance is Important
Now, how do you think the industry has done with going back and retrofitting systems? Good? No, not very good. So this is old information, but it's frankly good to bring up again to keep the awareness high that when you encounter a CO2 system or you're a user of CO2 and you don't see some of these things on your system, you need to go back and do that just to keep your system safe, or make it as safe as possible, because we still lose a couple people every year due to CO2 discharges.
Some of the available designs, total flooding. CO2 systems are one of the only systems that we can use for deep-seated fires, so when bulk material where the fire can be buried down in or burn long enough to get buried down in, we can use a CO2 system to attack that type of fire. A good example of that would be coal bins at a power plant. If I've got a coal silo full of coal. It's just moving into the power plant. If it sits long enough it can self-heat and combust inside of there, and so once the coal catches on fire, one of the only ways to put it out is with a CO2 system, so we'll inject CO2 low in the silo and high, and it will fill that volume and soak into the coal, and it can extinguish that type of fire. So that's what a deep-seated fire example for that. It deals well with uncloseable openings and even forced ventilation. If you can't shut off the HVAC or a fan or something like that, we can deal with that in the CO2 system.
Used for local application, for leaky spaces, we can do extended discharge systems. Some applications, flammable storage rooms. We use them a lot in power generation for turbines and generators, machinery rooms, steel production, printing presses, just a number of different applications for CO2 systems."