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  • new2cafs

    i finally decided to register and here is my first question. i realize cafs has foam solution and compressed air. what is the total amount of solution/air you can put through a hose at once, 1.75 hose for instance. is this dependant on different systems? different pressures? am i even asking a legit question ? any help would be appreciated

  • #2
    I am familiar with the Darley CAFS system.
    CAFS Systems are usually proportioned by some type of automatic proportioner such as FOAM PRO. The amount of air added to the line is done by valves on the pump panel. CAFS systems generally use Class A foam at a .1 to .3% mixture. Adding more or less air/foam will allow you to create a thicker or thinner foam blanket. Thought CAFS systems are great for wildland firefighter, in the world of structural firefighing, CAFS systems are not all that they are cracked up to be.

    1. CAFS is better because it is less damaging.
    --You are taught in basic fire school to bleed off the air before entering the structure. Anytime that you close a CAFS line, the air is forced to the bail in the nozzle. With CAFS lines, you must leave the nozzle cracked to avoid this situation. This causes you to advance through the house or building with a line flowing water/foam as you go.

    2. CAFS lines use less water.
    -- Many of us have been through flashover training of some sort. In that class we are taught to cool the atmosphere, inhibit pyrolsis, and avoid flashover. Water cools. Water will assist in preventing flashover. Do you want to "pencil" the ceiling with 1/2 the water that you could potentially have? Not to mention introduce compressed air to the situation.

    3. CAFS lines are lighter
    --CAFS lines also kink more easily than conventional lines.

    4. CAFS systems require more maintenance and training than conventional systems
    -- In today's world of less runs, less working fires, less manpower, and less money, does your department have the time to mess with CAFS?

    Comment


    • #3
      Hi CANfireems,

      The answer to your flow question is GPM is GPM. If you can flow 140 GPM of water through an 1 3/4 line, you will flow 140 GPM of CAFS through the same line. The volume of the hose is what it is.

      My department is using a Pneumax PTO system since 1998, with much success. Different manufacturers make CAFS in their own way. Some batch mix, some mix as it leaves the truck, in the fire hose itself. CAFS works and works very well in both the wildland and structural firefighter applications.

      To PHarper. I think you should learn and/or get more experience with CAFS. You stated: "in the world of structural firefighting, CAFS systems are not all that they are cracked up to be." I have been on the nozzle many times fighting an interior fire, with water only prior to 1998 and with CAFS since then and I can say with confidence based on my training, education, and hands-on experience with CAFS that it makes the job of firefighting much safer and more effective compare to just water.

      You say that air is problem if the nozzle is shut down. I can only assume that this is a Darley issue/problem. Our SOG's are to flow the line prior to making entry to get the CAFS to the nozzle. It has been my experience that the opposite occurs when we shut down the line. Some of the bubbles "POP" and we get a "wetter" stream. The air problem you describe has never happened with our Pneumax system.

      You stated: "CAFS line use less water". WRONG!!!! CAFS attack lines must flow the required/same GPMs to extinguish the fire as you would if you were attacking the with just water. You can use whatever formula you want to calculate the GPM flow. Whatever that GPM is, that’s the minimum flow you need. CAFS doesn’t flow less water, but less water is used to extinguish the fire because you don't have to flow the CAFS line as long (in time) compared to water. For example; if a room was on fire and you calculated that a 100 GPM flow was required, you might flow water for 3:00 minutes to knockdown the fire. With CAFS you would still have to flow 100 GPM however, you may only have to flow CAFS for 1:00 minute to achieve knockdown. Hence you used 300 gallons of water verses 100 gallons of CAFS to accomplish the same objective. CAFS makes water more efficient!

      You stated: "CAFS lines also kink more easily than conventional lines." We have not had any kinking problems. We are using double jacketed cloth fire hose and pump our handlines between 80 and 100 psi. No kinks.

      Finally you stated: "CAFS systems require more maintenance and training than conventional systems
      -- In today's world of less runs, less working fires, less manpower, and less money, does your department have the time to mess with CAFS?"

      Yes there is maintenance on a CAFS system, but it is minimal at least on the Pneumax system. A couple more filters and oil, and run the system.

      With your philosophy on training we should do away with portable radios, turnout gear, SCBAs, gas meters, thermal imaging cameras and anything else that requires "maintenance" or “training”,

      Bottom line is that CAFS works and works very well. Education and training is the key. You must do both or somebody will get hurt. The cost is worth the benefits.

      Hope this helps CANfireems.

      Be Safe,

      Capt. Lou
      "Got Foam?"
      Last edited by CaptLou; 07-03-2003, 12:55 AM.

      Comment


      • #4
        We have had our CAFS for over a year on a Pierce with Foam Pro system and am very glad we decide to go with CAFS.
        Just about everyone who has seen it work was very impressed with the very small amount of water we use to extinguish the fire.

        To answer your question yes it is for thicker or thiner foam.

        as for above statement would like to correct a few things

        #1 Foam Pro only uses .01% to 1%. We start of with .03% go to .01% for overhaul. Thats only 3 gal of foam for every 1000 gal of water.

        #2 CAFS will cool with much less water so less likely for flash over. You do not have to leave the nozzle on you just turn it off.

        #3 Statement is correct you will have to watch for that one.

        #4 Have not had any maintenance problems so far. Training was no big deal it is very simple to operate.

        We are very happy with ours and it was worth having. Would not buy another engine without it.

        If you can find departments with CAFS go talk to them. and I think your next engine will have CAFS

        Comment


        • #5
          CAFS can

          Have you considered a CAFS fire extinguisher. I own one produced by Hawk international and have used it in live fire training. I was able to extinguish six pallets and three bails of straw that were fully engulfed in flames in a bedroom. I used only half of the extinguisher's contents. In addition there was little or no rekindle because of the penetration of water due to the foam. The can is a typical looking water can.( 2 gallons.) This fire would have been considered a good room and contents woking fire by most standards.

          Jim.

          Comment


          • #6
            foam cafs

            You should check out part of the fourm that mentions how to make home made cafs systems

            Comment


            • #7
              Originally posted by PHarper
              I am familiar with the Darley CAFS system.
              CAFS Systems are usually proportioned by some type of automatic proportioner such as FOAM PRO. The amount of air added to the line is done by valves on the pump panel. CAFS systems generally use Class A foam at a .1 to .3% mixture. Adding more or less air/foam will allow you to create a thicker or thinner foam blanket. Thought CAFS systems are great for wildland firefighter, in the world of structural firefighing, CAFS systems are not all that they are cracked up to be.

              1. CAFS is better because it is less damaging.
              --You are taught in basic fire school to bleed off the air before entering the structure. Anytime that you close a CAFS line, the air is forced to the bail in the nozzle. With CAFS lines, you must leave the nozzle cracked to avoid this situation. This causes you to advance through the house or building with a line flowing water/foam as you go.

              2. CAFS lines use less water.
              -- Many of us have been through flashover training of some sort. In that class we are taught to cool the atmosphere, inhibit pyrolsis, and avoid flashover. Water cools. Water will assist in preventing flashover. Do you want to "pencil" the ceiling with 1/2 the water that you could potentially have? Not to mention introduce compressed air to the situation.

              3. CAFS lines are lighter
              --CAFS lines also kink more easily than conventional lines.

              4. CAFS systems require more maintenance and training than conventional systems
              -- In today's world of less runs, less working fires, less manpower, and less money, does your department have the time to mess with CAFS?

              I realize that this thread is quite old, but I figured I'd throw in my $0.02
              First of all, don't listen to PHarper, he obviously has absolutely no idea what he is talking about. I'm a firefighter and instructor on a large municipal fire department, and we have a number of CAFS engines. They run great, and they are absoluetly well suited to urban and structural firefighting.

              To correct some of his statements...
              1.) The air is not forced up to the end of the nozzle. You can safely shut the nozzle off and move through the structure without leaving this "trail of water and foam". I've never heard that one before. When you initially open the nozzle there may be a very limited amount of "slug flow" from the air, but this will disappear almost the second that you open the line. You most certainly don't have to leave the line cracked open.

              2.) I don't even know where to begin correcting this statement. First of all, you do not have half the amount of water as with a standard line. While water amounts are reduced, they are most certainly not at half of what you would have on a Class A line or a straight water stream.

              Secondly, the water that you do have is a more effective fire stream than either of these previous two would be. CAFS introduces the foam (which is referred to as a surfactant, and lowers the surface tension of the water, therefore allowing it to better coat and penetrate materials that are burning) as well as compressed air in a very precise measured amount to delived a uniform fire stream. The bubbles that are created are a uniform size and shape, and the stream actually is able to be delivered more efficiently and effectively to the fire.

              Third, the statement "Not to mention introduce compressed air to the situation" makes it sound like you're blowing air around out of the end of the line. This is incorrect. The air is injected into the hose line and assists with the aspiration of the fire stream. What comes out the end of the nozzle is a very effective fire stream, not a bunch of compressed air. PHarper...what do you think is mixed with the water that is coming out of your fog nozzle?

              Fourth, who taught you to pencil with a CAFS line in a flashover environment? That is fundamentally incorrect. A CAFS line should never be penciled, the proper way to apply CAFS in such a situation (as a matter of fact in all situations) is to use the painting technique. The bail on your nozzle (which MUST be a smooth bore nozzle, not a fog nozzle BTW, as a fog nozzle will strip the uniformity of the CAFS bubbles and deliver a less effective stream) should be FULLY open, and you will make a fluid application of the CAFS stream from one end of the ceiling to the other, then back to where you started, and then shut the nozzle down. This is how a CAFS stream is correctly delivered. When done this way there will actually be LESS disruption to the thermal layering in the super heated environment, less steam pushed down on the firefighters, and a quicker knock down, along with better visibility.

              3.) The lines are lighter, and they do kink easier. So I guess it's a matter of paying attention to what you're doing. If a kinked hose line is going to totally screw up your fire attack I think you have more serious issues to address than worrying about the possibility of your line getting kinked. If it does, go and un-kink it. Problem solved.

              4.) Our CAFS systems have proven to be very reliable, and with many usages on a daily baisis have never let us down.

              "In today's world of less runs, less working fires, less manpower, and less money, does your department have the time to mess with CAFS?"

              YES! WE DO! In today's world of firefighting as engineers do we not want to aspire to have some sort of pride and some sort of abilities to run our apparatus? Maybe you should go back to a bucket brigade, because in today's world of less fires and manpower we don't have the time to learn new things? You've lost me on that one. As engineers we should be motivated to stay up to date on the latest inovations, and to keep on top of our profession. CAFS is a great system, and many departments are using it with great success worldwide. I will concede that you probably haven't had very good experiences with it based on your post. But based on your post you have no idea how to operate the system, or how to run the nozzle when you're working with it. I would suggest that before you criticize a system that you clearly know nothing about, you do some research!

              -FF21

              Comment

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