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  • CAFS question

    speaking from a department that has eductors in the compartments....

    does a foam proportioner inject concentrate into the individual discharges or into the pump discharge manifold?

    does a CAFS system inject air into the individual discharges or into the pump manifold?

  • #2
    SBrooks,

    Among the most popular systems on the market today, an additional foam manifold is added to the discharge side of the pump, and all foam-capable discharges are plumbed through this manifold. The foam manifold is separated from the main discharge manifold by a check valve, to prevent contamination of the pump with foam concentrate.

    The foam concentrate is injected into the foam manifold, and conseqently all foam-capable discharges that are flowing will be flowing foam solution.

    Air for the CAFSystem, however, is injected into each individual discharge. Each individual foam-capable discharge that you want to be CAFS-capable is equipped with an air valve (downstream of the discharge valve). Therefore, when you want CAFS, all you need to do is open the air valve to a discharge that flows foam solution, make the necessary adjustments to the discharge valve flow, and you have CAFS.

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    • #3
      Is there a check valve for each individual CAFS discharge?
      How is the air flow matched to the water flow? Manually?

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      • #4
        Yes there are check valves for each discharge - one on the air side and one on the water side. There is also a check in the foam manifold between the pump and the foam inject point, as well as one in the foam concentrate line between the manifold and the foam pump.

        Air flow and water flow are balanced by pressure - then depending on how your system is set up (manual or electric air valves) you can regulate the air flow by increasing or decreasing your water (electric or manual air valves) or by gating your air valves (manual air valves only)

        As a note my history is with the Waterous Pneumax systems but I think the others all have the same basic principles –I believe some of the others have a larger mixing system and no individual air valves for each discharge.

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        • #5
          Basically the air flow remains steady with the CAFS systems I am aware of. To adjust your foam (wet or dry) you adjust your water discharge valves. All the way open= more water = wetter foam, etc.

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          • #6
            On our engine when running CAFS, if you open the discharge valve all the way you will get only water, no air. With the valve shut, you will receive only air coming through the line. You balance your CAFS stream in between.

            We have made templates for our discharges using plastic pipe, the engineer opens the water valve and clips the template on the valve rod, then he pushes the valve back in until the plastic pipe is wedged. Run the throttle up to pressure and you have a CAFS attack stream without the guesswork. We have not had any problems using this method.

            Chris, very nice Crimson you have up there in Wisconsin, hats off to the many innovations once again!!

            Comment


            • #7
              Cafs

              Check out this website. It should answer your questions.


              http://cafsinfo.com/
              I have only 2 allegiances, to my country and to my God. The rest of you are fair game.

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              • #8
                PrestoC1 - Thanks! We tried a few new things - are very pleased with it so far - it was nice to have the opperunity to build a second unit based on the first with the ability to improve on the things we did not like. Both the Saulsbury and the Crimson have been very good units.

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                • #9
                  Hey, is it possible to get 100 gpm & 50 CFM through a 1 1/2" line? If not, what size hose do you need?

                  Is it possible to get 120/60 through 2"

                  What size hose is required for 65/65 flow?

                  Comment


                  • #10
                    SBLGFD

                    We run cafs and have excellent success,anyway a little off subject one of my guys told me about your website, and your hydrant/fill truck. We're pretty big in moving water until we purchased our foam truck,but I am very impressed with your truck and the set up of it.Can you put more LDH on it or not? What you have is great,I'm just being curious.BE SAFE

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                    • #11
                      dday05- Thanks for the positives on the hose truck - it carries 4000' of 5" each length is 200' long - special ordered to keep the number of couplings down. We could get a little more on if we had to but the issues comes in that if we don’t roll it up tight it egg shapes after a while and the drags on the floor for the first couple of rounds. This is our issue as we had then build it as low as possible it should have had an additional 3-4 inches of height between the reel and the deck. All in all it works well - hope that answers your question.

                      SBrooks - yes you should be able to do both - I was pumping Elk Grove township's new unit today - 150 1 3/4 - 130-140 GPM with a 1 1/8 tip 100-110 with a 15/16 - they don’t have a air flow meter so I cant give you the air flows on this unit. If you specifically need to know about 1 1/2 when I get home I can run some out and give it a try.

                      Comment


                      • #12
                        SBLGFD - this is all curiousity on my part so I don't *NEED* anything, but I'd certainly like it, I hope you understand.

                        My department uses 1 1/2" lines almost exclusively. We tried 1 3/4", didn't like it. I think the difference would be less with both lines 1/3d full of air.

                        For a given hose / nozzle combination is there a wide breadth of flows that 'work'? From what I've read, it seems that all lines use a fairly narrow range of pump pressures, and the flow is determined by your hose / nozzle combination. Is this true?

                        Has anyone used the TFT Cafs Nozzle?

                        Comment


                        • #13
                          SBLGFD

                          What pump pressures were you using to obtain those flows? We have had our system over 2 years now, and even though we have a set procedure, I still like to experiment with it and see if I can tweak it just that little bit more. We are running 1.5" lines with solid bores (7/8" tip or none at all, 1 3/8" orifice in the valve) and a 2.5 " line with a blitzfire/1.5" solid bore tip.

                          Also, anyone having problems with the lining inside the hose when using CAFS? We have had a couple sections self destruct on the inside.

                          Comment


                          • #14
                            Has anyone used the TFT Cafs Nozzle?
                            I haven't used it personally, but it seems rather stupid: if the ideal nozzle for CAF production is a solid bore, why should we take a fog nozzle and try to make the waterway smoother? It is still never going to as good as a smooth bore. Bring a screw on fog tip if you want, but don't try to make a "CAFS fog nozzle". (nothing against TFT - I am a big fan of a lot of their products)

                            Also, anyone having problems with the lining inside the hose when using CAFS? We have had a couple sections self destruct on the inside.
                            Probably not an issue specifically with CAFS. We've had some problems with hose delaminating with plain water or Class A foam. What brand and model of hose are you using?

                            Comment


                            • #15
                              Originally posted by BlitzfireSolo
                              I haven't used it personally, but it seems rather stupid: if the ideal nozzle for CAF production is a solid bore, why should we take a fog nozzle and try to make the waterway smoother? It is still never going to as good as a smooth bore. Bring a screw on fog tip if you want, but don't try to make a "CAFS fog nozzle". (nothing against TFT - I am a big fan of a lot of their products)
                              TFT had to do something for those people who have to spend the most money possibly on a nozzle. Like their ridiculously overpriced automatic fog nozzles. Leave it to them to take the simplest product and make it as complicated as possible for as much as possible. We've got guys citing excellant results with CAFS from an open butt and someone has to make a tip to complicate things.

                              Comment

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