Class K fire extinguishers

[Hotelsecurity]

The NFPA regulations on Class K fire extinguishers drive me crazy. The over the hood central system is to be discharged BEFORE the class K extinguisher is used. To me it sounds like the sprinklers are to be turned on before the pressurized water extingusiher is used. Is the purpose of hand held extinguishers not to fight a small fire before it gets large enough to set off the hood & sprinkler systems? And once the central hood system has gone off, what's the use of the extinguisher?

[CKL958]

Originally Posted by Hotelsecurity

The NFPA regulations on Class K fire extinguishers drive me crazy. The over the hood central system is to be discharged BEFORE the class K extinguisher is used. To me it sounds like the sprinklers are to be turned on before the pressurized water extingusiher is used. Is the purpose of hand held extinguishers not to fight a small fire before it gets large enough to set off the hood & sprinkler systems? And once the central hood system has gone off, what's the use of the extinguisher?

Give me a day or two with this. I do have some literature and such on it stashed somewhere (I'm in the process of ripping everything apart doing some cleaning and I'm not sure where that end of things has ended up).

[Michael13]

Originally Posted by Hotelsecurity

The NFPA regulations on Class K fire extinguishers drive me crazy. The over the hood central system is to be discharged BEFORE the class K extinguisher is used. To me it sounds like the sprinklers are to be turned on before the pressurized water extingusiher is used. Is the purpose of hand held extinguishers not to fight a small fire before it gets large enough to set off the hood & sprinkler systems? And once the central hood system has gone off, what's the use of the extinguisher?

I've heard a Hood tech say this, that because of the new K extinguishers, staff are grabbing them and getting the fire out before the system discharges, nor are they using the manual discharge pull lever. They aren't seeing as many service calls for the systems, because they don't get discharged. Good for the overall situation, the less fire damage and cleanup from a whole system discharge but bad for service companies. Thats the way it goes.

What NFPA most likely says, is that the system is to discharge first because it's designed to extinguish the fire and has larger extinguishing capabilities. This keeps the people out of harms way, rather than them attacking with a portable.

If someone can get a fire out using a portable rather the system dumping, as well resulting in the fire alarm system activating therefore having FD respond (hood systems are usually tired in), it's a better situation. FD still should be called, but they can now respond less urgent and the building doesn't get evacuated.

We'll see what CKL958 finds.

[itsnotahobby]

Remember as well that there is a device to shut off the power and or gas to the appliance once the manual pull is activated or the system activates automatically. If you just use an extinguisher you would have to manually shut off the fuel supply which may not easily be done. Another thing to consider is that workers are not firefighters. Most get no training at all except for "theres the extinguisher over there", which is usually behind some boxes or something. I for one would never want to see an employee attempt to put out a fire with an extinguisher. I'd rather them pull the manual activation and then evacuate and wait for us.

Also remember that clean up from a wet chem system is a hell of a lot less than that of the old dry chem systems.

[CKL958]

Couldn't find what I was looking for. I totally agree with Michael13 and itsnotahobby though.

[CKL958]

I know what I was thinking of now. It wasn't literature. It was a promotional video (I believe Amerex...) that showed the effectiveness of the K-Class against a BC powder. I can't find it online anywhere, but I'm running dial-up, and can't reasonably view videos. Both the K-Class and the BC produce a fairly violent initial reaction, that I would want to be wearing long sleeves, gloves, and a face shield to use.

That said, what itsnotahobby mentions about shutting the heat source down is quite important. The idea behind the K is that being a liquid, it acts as a cooling agent as well as smothering. The video showed repeated use of the BC on the same fire, and it kept restarting itself. The K was more effective as it cools (Eliminating one of the elements of the Fire Triangle/tetrahedron [dependant on which model you feel like talking in])

Additionally, I don't see that there would likely be that much of a cost savings to use one piece of equipment or the other, and in the case of pulling the manual activation handle for the suppression system, you have alerted the fire department (if you are monitored) as well as the occupants of the building that there is a problem. Additionally, how do you answer your insurance company if they ask why the fixed suppression system was not used (in the case of large damages).

On top of all that, if you let the system do it's job, and it does re-kindle itself, you have left an extinguisher that will be an effective tool for the fire dept, should they need it.

I wish I could find that video.

[Nagrom]

Originally Posted by CKL958

On top of all that, if you let the system do it's job, and it does re-kindle itself, you have left an extinguisher that will be an effective tool for the fire dept, should they need it.

I haven't been around any kitchen fires, so I have a question. How well does dry chem work on a K class fire?

I ask this, because I've always been taught not to use extinguishers found in buildings, and that we should use the ones on our trucks. If a class K is going to work way better, which I suspect it would, I wouldn't mind using one as much, but, which road to choose?

[CKL958]

Originally Posted by Nagrom

I haven't been around any kitchen fires, so I have a question. How well does dry chem work on a K class fire?

I ask this, because I've always been taught not to use extinguishers found in buildings, and that we should use the ones on our trucks. If a class K is going to work way better, which I suspect it would, I wouldn't mind using one as much, but, which road to choose?

It will work, but you'll have a difficult time extinguishing. It will keep flaring back up. You'll dump many an extinguisher on it as the heat is so great that it basically ignites itself. That's why (among other reasons) the hood systems have all gone wet.

It should be noted, that ABC drychem extinguisher is not compatible with the Wetchem agent in the fixed suppression systems. The wetchem works on the principle of soapification, and creates a "bubblebath" on top of the cooking media. The ABC will deflate the "bubblebath", however, a BC will not. (They are different chemicals. The BC is a sodium bi-carb - baking soda, can't recall the ABC chemical name - it's long).

I would agree generally about not using the extinguishers in buildings. Riding on the truck, you have no clue about the maintenance (or lack thereof) performed on them. In reality, how many of us carry a BC on our truck that will be compatible with the wetchem coming out of a suppression system.

I hope this helps... If you have any questions or anything... giv'er....

[Hotelsecurity]

Originally Posted by Nagrom

I haven't been around any kitchen fires, so I have a question. How well does dry chem work on a K class fire?

I ask this, because I've always been taught not to use extinguishers found in buildings, and that we should use the ones on our trucks. If a class K is going to work way better, which I suspect it would, I wouldn't mind using one as much, but, which road to choose?

Yhe Class K extinguisher turns the burning grease into soap. Clean up is way easier than with powder & it doesn't spread all over the kitchen.

[Hotelsecurity]

Originally Posted by CKL958

I know what I was thinking of now. It wasn't literature. It was a promotional video (I believe Amerex...) that showed the effectiveness of the K-Class against a BC powder. I can't find it online anywhere, but I'm running dial-up, and can't reasonably view videos. Both the K-Class and the BC produce a fairly violent initial reaction, that I would want to be wearing long sleeves, gloves, and a face shield to use.

I think that this is why these extingusihers have a long wand at the end of the hose.