Clean Agent System Code Requirements

Posted by Lee Kaiser on Mar 7, 2018 10:05:00 AM

This video covers some recent code changes for clean agent systems. Some new requirements for systems protecting Class C hazards began  in 2016. Other requirements for monitoring control heads in order to address the practice many people have of disabling their systems began at the same time - supervisory control head monitor switches. Finally we offer an opinion on regulatory changes that may be coming in the future with regard to clean agents. In this video, fire protection expert Lee Kaiser explains the new requirements and why you should implement them in your clean agent system.


Video Transcript

Lee: "For Class C fires, those electrical fires, a number of years ago, well the 2012 edition of NFPA 2001, The Standard on Clean Agent Firing Extinguishing Systems, the technical committee for gaseous fire suppression systems expected that there are going to be more Class C fires, because there's a trend in that the heavy users of these IT spaces to tend to not want to shut off the power to their equipment. They want to just ride through the fire, so they expect more sustained Class C ignition sources. In response to that, they increased the safety factor required in the code for Class C fires from 20% to 35% so the net result is that systems are going to be a little more expensive as you saw them today because we have to put in a little bit more gas. 

Requirements are Not Retroactive

Now, the question that always comes up is if I have an existing system, is that a retroactive code requirement?  Do we have to go back and add gas to my cylinders? The answer is no. In fact, you should expect this.  There is no loss history in the industry that shows that we needed that extra percentage of gas.  We know we're having Class C fires - users are not shutting down the power and they're having fires a couple a month is what we kind of understand is happening in the United States - and we're not losing any of those buildings.  Those systems are still extinguishing fires and they're not under this new code, those systems aren't, but yet, you know, if you're putting in a new system, this is what you're going to have to do with your new system. 

Position Monitoring Switches

Another requirement that we feel that you should go back and do, even though it's not retroactive, is the requirement to add position monitoring switches, or to electrically supervise the position of the actuation device, okay, so threw a lot of terms in there, but one thing we use is a control head to actuate the bottle or open the valve for a system, so this picture here in the bottom right shows a red clean agent cylinder with this brass right angle valve that's closed normally, until we actually fire a little pin down using a solenoid device.  We call this a control head and when we attach the control head to that cylinder and it's tied into a releasing fire alarm panel, then it can activate that bottle to open it up and send gas into the enclosure. 

Now, this control head has a little nut that threads onto the top of that valve and usually that control head is connected by flexible conduit meaning that it's meant to be removed from time to time, usually to service the system on an annual basis, but users of this type of equipment have figured out that they can disable the system by removing that control head, so they can do something that might cause an accidental discharge without actually causing that discharge, so from time to time our service technicians will go into a space protected by clean agents and find the control head hanging by the side of the tank, and so when that's in that position, you have a very expensive paperweight because the system's not going to activate, so that's a huge deal because we get no warning that the control head is not attached.  Otherwise, the panel's green, dumb, fat and happy and everything's good.  Well, now with the use of a position monitoring switch, which is a device that sits between the control head and the valve, it knows if that device is there or not and when it's engaged everything's fine and normal at the panel, but when we remove that control head then we get a supervisory signal at the panel knowing that we have an off normal condition meaning we have to go back and restore it to its normal condition at some point or another. 

New Systems, New Requirements

This is a good reminder for you, if you're in that practice of removing a control head to disarm the system.  We'd rather not have anybody do that.  We'd rather have a keyed disconnect switch or other type of switch to disable the system, when you need to do maintenance on that, so those two things in combination, adding position monitoring switches for supervisory warnings of the control head being removed and agent disconnects, which those are two good safety upgrades that you should put in your system, even thought that code requirement's not retroactive and that became required as of January 1, 2016."

Topics: Fire Protection Services, Suppression, Fire Protection Systems, Video Blogs, Nationwide

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