Leader

Collapse

Announcement

Collapse
No announcement yet.

Need help with an age old Debate!

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Need help with an age old Debate!

    Hey guys/ gals, I am certain this has been debated time and time again but for the life of me (or due to the fact that I am new to this forum) I cannot find any of the information that I need.
    My Department currently has 1997 KME TL (102') that has an Elkhart sm2000 Fog tip on the monitor. We have run numerous flow evaluations with this current setup on my crew, and have proven time and again that this nozzle just does not give us the reach and penetration that we would like to see from an elevated master stream. I have gone to the Chief and suggested that we replace the fog tip with a smoothbore nozzle with tips of 1 1/4", 1 1/2" and 1 1 3/4", which we currently have off the old ladder truck. I know we won't be able to flow 1000 gpm with this set-up like we could with the fog but, my thought is that even with 800 gpm from the 1 3/4" smoothbore, reach, penetration and actual GPM on target would far surpass our current setup. Although he has not shot down my idea, he has asked me to come up with a comprehensive report on the pro's and con's of each nozzle. More or less I have to sell it to him before he will decide. Does anybody out there have any literature or information that I can use to try and convince the Chief? Any and all will be greatly appreciated

  • #2
    Originally posted by EngineGuy51 View Post
    Hey guys/ gals, I am certain this has been debated time and time again but for the life of me (or due to the fact that I am new to this forum) I cannot find any of the information that I need.


    My Department currently has 1997 KME TL (102') that has an Elkhart sm2000 Fog tip on the monitor. We have run numerous flow evaluations with this current setup on my crew, and have proven time and again that this nozzle just does not give us the reach and penetration that we would like to see from an elevated master stream.


    I have gone to the Chief and suggested that we replace the fog tip with a smoothbore nozzle with tips of 1 1/4", 1 1/2" and 1 1 3/4", which we currently have off the old ladder truck. I know we won't be able to flow 1000 gpm with this set-up like we could with the fog but, my thought is that even with 800 gpm from the 1 3/4" smoothbore, reach, penetration and actual GPM on target would far surpass our current setup.


    Although he has not shot down my idea, he has asked me to come up with a comprehensive report on the pro's and con's of each nozzle. More or less I have to sell it to him before he will decide. Does anybody out there have any literature or information that I can use to try and convince the Chief?


    Any and all will be greatly appreciated


    First of all, reach and penetration is a must.

    Why not set up a demo and show the powers there, the reach od the soild bore tip vs. the fog tip. You can get a 2 inch smooth bore that flow 1000 and some change. The best be if you don't have a stream streightner which goes on the monitor and the tips fit on the other end will give a great flow.

    Too bad members get this mind set for heavy aerial streams has to be a fog where the solid bore does a better job for the reach and penetration operation.

    The fog nozzle has its place too.

    The best of two worlds is having duel monitors up in the platform!!

    Stay Safe and Well Out There....

    Always remembering 9-11-2001 and 343+ Brothers

    Comment


    • #3
      Sounds like your Chief needs to be educated alittle concerning the differences of flowing water through a monitor vs a smooth bore.

      The main problem with a monitor is it is acceptably known that it could lose close to half of the water thrown at a big fire due to the extreme heat, and the water being droplets. The radiant heat will vaporize the droplets to steam, instead hitting the fire. You lose trying to get penetration. If it is windy, you also lose when using a monitor. If you've gone defensive, your wasting water and time with a monitor. It doesn't have the reach or power for a knock down attack. As well, there is a "wind" effect with a monitor. That "wind" effect can possibly cause the fire to spread to another area. Not good.

      As for changing over to a smooth bore, you can hit it hard with alot of water and gain reach, knock down, and penetration. You also don't have the loss of water on the target due to wind or radiant heat vaporization compared to a monitor.

      A 1 3/4 smooth bore may not flow as much as a monitor does, but it is more effective in getting the wet stuff on the hot stuff. And do install a stream straightener if you can.

      Our platforms are mounted with one of each. All straight sticks have smooth bores mounted, and have monitors if they want or need them.

      FM1
      I'm the one Fire and Rescue calls, when they need to be Rescued.

      Originally posted by EastKyFF
      "Firemens gets antsies. Theys wants to goes to fires. Sometimeses they haves to waits."

      Comment


      • #4
        Sounds to me like this KME / LTI might be a rear mount. In my experience, these aerial platforms have a very high friction loss between the pump and the base of the aerial. If memory serves me correctly, there is a separate inlet directly to the ladder located on the rear. Try running a 50' - 3" or 50' of 5" from the officers side discharge around to the rear intake. use both the internal piping and the external hose line when feeding this platform at flows over 800 gpm.
        You need to do some testing of the losses in the rig. Put the 1 3/4" tip and shaper on the platform and set the basket at ground level. Using a pitot gauge have the pump operator increase discharge until you actually get 80 psi at the nozzle tip. Compare the pump discharge with the 80 psi. I can't find my notes from the aerial calss with Emporium, Pa, but my memory says it was almost a c=1 number. This means that the losses inside the aerial are approximately equal to the square of the flow in 100's of gpm's. A 1 3/4" tip is 813 gpm at 80 psi. Divide 813 by 100 and square the result so.... 8.13 x 8.13 = 66.09 and allow 20 psi for the device piping. So you will need an EP of about 166 psi to supply 813 gpm out the tip. If you were supplying the automatic nozzle, you would need about 184 psi at 800 gpm. By the time you reach 1,000 gpm you will need 220 psi of engine pressure to do the job. If your rig has a 1500 gpm pump, you will have a hart time reaching 1,000 gpm because the pump can not do both high volume and high pressure at the same time unless helped by higher incoming pressure (above 20 psi).

        Comment


        • #5
          Thanks guys for the replies. As far as setting up a head to head demonstration, I wish I could but, in order to place the Pipe on the monitor we need to purchase a 3 1/2"- 2 1/2" reducer. We do have a stream straightener, and I doubt it would cost a bundle to get a 2" nozzle so we could flow 1000 gpm. This is why the Chief needs/ wants a detailed pro's and con's report, so he can justify to the City Manager why we need to spend any money.

          KuhShise, yes it is a rear mount, with a 2000 gpm Hale pump.

          As far as Flows go, we have tested the rig with the Fog nozzle and have found, that through the pump, we need an EP of 240 and through the rear intake we need an EP of 190 to obtain 1000 gpm. I have asked the question of flowing through the pump as well as feeding the monitor from the rear from a different source in order to obtain higher flows. I was told that it was not a good idea due to the fact that the rear intake is also a discharge and that you would need both ends flowing at the EXACT same pressure in order for the water to to reach the platform. Is this correct?

          Comment


          • #6
            Engineguy51:
            Seems like you have done most of the work to determine the “C” for the aerial. Here is the table I would use for this apparatus running the automatic nozzle.

            500 gpm - 135 psi EP
            750 gpm - 180 psi EP
            1,000 gpm - 240 psi EP

            1 ¼” tip - 413 gpm - 105 psi
            1 ½” tip - 597 gpm - 130 psi
            1 ¾” tip - 813 gpm - 175 psi
            2” tip - 1,067 gpm - 240 psi

            Friction loss for this rig based upon your info seems a bit high, but for any flow desired, take the flow and divide by 100 and then square that number Lets say you wanted to deliver 700 gpm. 7 X 7 = 49 times the “C” of 1.4 and the loss inside the aerial waterway will be 68.6 psi. Then add in the nozzle pressure (Auto = 100) so EP needs to be 168.6 (170) plus the elevation pressure of ½ psi per foot. I suspect that when you stated the 240 EP for 1,000 gpm, it was with the nozzle in an elevated position. That is why I suggested the basket at ground level in my original post.

            I was suggesting that you simply run a line from another discharge on the aerial’s pump and parallel the internal plumbing in the rig, so technically it is not two separate sources (engines) supplying the aerial. Your information stating the rear inlet needed an EP of 190 psi did not specify a hose lay from the second engine to the rear inlet. If you could provide that information, then it is possible to back calculate and provide a second set of tables for running the hose line (3” or 5”) from the aerials pump discharge around to the rear intake.

            If you were to supply from both the quint’s pump through the truck piping, and from a second engine at a separate source into the rear, there would need to be a little co-ordination between the two pump operators. I would start both pumps out at say 150 psi and have the basket operator bring both up in tandem. It would not be absolutely necessary to have the exact same engine pressures on both rigs. We already know that it is possible to supply a Siamese from two separate sources on the fire ground, since this is a common practice when using two sources feeding a single engine. The aerial would be no different. Just be aware that it is possible to use one engine to force water backwards through the other source if the pump pressure on the second is allowed to fall too low. This can be a serious situation if one source is the municipal water supply and the other is river water.

            Put a cap and gauge on the rear inlet and provide a reading at that point with water flowing (known quantity) out the nozzle. Also a nozzle elevation if you have the basket elevated. This will provide a measure of the piping losses between the pump and the rear intake.

            Check this thread: http://www.firehouse.com/forums/showthread.php?t=115659
            Last edited by KuhShise; 08-17-2010, 11:02 AM. Reason: Added reference thread

            Comment


            • #7
              Originally posted by EngineGuy51 View Post
              Thanks guys for the replies. As far as setting up a head to head demonstration, I wish I could but, in order to place the Pipe on the monitor we need to purchase a 3 1/2"- 2 1/2" reducer. We do have a stream straightener, and I doubt it would cost a bundle to get a 2" nozzle so we could flow 1000 gpm. This is why the Chief needs/ wants a detailed pro's and con's report, so he can justify to the City Manager why we need to spend any money.

              KuhShise, yes it is a rear mount, with a 2000 gpm Hale pump.

              As far as Flows go, we have tested the rig with the Fog nozzle and have found, that through the pump, we need an EP of 240 and through the rear intake we need an EP of 190 to obtain 1000 gpm. I have asked the question of flowing through the pump as well as feeding the monitor from the rear from a different source in order to obtain higher flows. I was told that it was not a good idea due to the fact that the rear intake is also a discharge and that you would need both ends flowing at the EXACT same pressure in order for the water to to reach the platform. Is this correct?


              What you could do and I have done it. Get the dealer for the brand of monitor you are using, Elkhardt or Akron and ask then if they have a reducer and a 2" tip that you can use to show the flow of the solid bore tips vs. the fog nozzle.

              Most dealers or company reps are happy to help you out. Not knowing how big your department is, but as for us we never hade a problem as most dealers and salesman for the company usually have loaners and are too happy to let departments use them to test with.

              You would be surprised on how the cost for those items are not that expensive.
              Stay Safe and Well Out There....

              Always remembering 9-11-2001 and 343+ Brothers

              Comment


              • #8
                Originally posted by EngineGuy51 View Post
                Thanks guys for the replies. As far as setting up a head to head demonstration, I wish I could but, in order to place the Pipe on the monitor we need to purchase a 3 1/2"- 2 1/2" reducer. We do have a stream straightener, and I doubt it would cost a bundle to get a 2" nozzle so we could flow 1000 gpm. This is why the Chief needs/ wants a detailed pro's and con's report, so he can justify to the City Manager why we need to spend any money.
                That is a $35 reducer. Dip into the popmachine can if it is needed (why?).

                Your local Akron/Elkhart/TFT regional reps should have a 3-1/2" stacked tip set on their truck. Akron is 3499 is 3-1/2" base with 2 1⁄4" X 2 1⁄2" X 2 3⁄4" tips. Intermediate and end threads are 2-1/2" which will allow you to stack other little tips if required.

                Comment


                • #9
                  neiowa, you are correct, the reducer is amazingly cheap. I have considered purchising it myself or see if the Union would be willing to buy it, but I'm concerned with setting a precident like that. Still would not gaurantee we could use it if the Chief doesn't sign off on it.

                  KuShise, when we ran our flow tests we used 100' of 5" hose, to supply the pump from another engine, and the same hose set up to supply the rear inlet from another engine. Neither was used at the same time, meaning we either supplied the areial through the pump or throught the rear, never at the same time. All was done from a municipal source. We do have a pressure gauge at the rear inlet, and we determined that, we needed 190 psi at the gauge to obtain flows of 1000 gpm with the fog nozzle. I hope this helps.

                  Comment


                  • #10
                    EngineGuy: If you run 100 ft. of 5" from a large discharge to the rear, and open both the internal valve to the rig piping and the LDH valve, you should be able to drop the pump pressure to about 195 psi. It will be a whole lot easier on your pump / engine system. The water will divide such that the flow in the 5" will be about 735 gpm and the flow in the body piping will be about 265 gpm. There is a problem with using 5" line at this pressure...?? What pressure do you test your LDH at for the annual test? Anything above 180 or so should require high pressure LDH hose.

                    If you run 50' of 3" from a large discharge to the rear inlet, then you will need about 207 psi PDP instead of the 240 psi you need to shove it all through the apparatus piping. It does make a difference with this apparatus. I believe that the small piping is intentional, to make sure no one overloads the basket with reaction force + live firefighter load. Attempting to reach flow rates above 1,000 gpm should cause the basket load to be reduced to one firefighter.

                    Comment


                    • #11
                      Originally posted by EngineGuy51 View Post
                      neiowa, you are correct, the reducer is amazingly cheap. I have considered purchising it myself or see if the Union would be willing to buy it, but I'm concerned with setting a precident like that. Still would not gaurantee we could use it if the Chief doesn't sign off on it.
                      ....
                      Yeah, thats an "issue". Perhaps organize a pancake breakfast, spaghetti supper, tractor pull, send out fundraising letter, write a local grant. Like most of us out here in flyover country.

                      Comment


                      • #12
                        Originally posted by CaptOldTimer View Post
                        The best of two worlds is having duel monitors up in the platform!!


                        Good idea! Whichever one wins the duel, that's the one you use!






                        Yeah, I know I'm a smart*****.......
                        Chief Dwayne LeBlanc
                        Paincourtville Volunteer Fire Department
                        Paincourtville, LA

                        "I have a dream. It's not a big dream, it's just a little dream. My dream — and I hope you don't find this too crazy — is that I would like the people of this community to feel that if, God forbid, there were a fire, calling the fire department would actually be a wise thing to do. You can't have people, if their houses are burning down, saying, 'Whatever you do, don't call the fire department!' That would be bad."
                        — C.D. Bales, "Roxanne"

                        Comment


                        • #13
                          Originally posted by dmleblanc View Post
                          Good idea! Whichever one wins the duel, that's the one you use!






                          Yeah, I know I'm a smart*****.......


                          Use both at the same time. If the truck, pump, waterway and everything else is designed to, no reason why both, Fog and Solid or maybe two solid streams going at the same time.

                          There are plenty of apparatus photos around showing this operation.
                          Stay Safe and Well Out There....

                          Always remembering 9-11-2001 and 343+ Brothers

                          Comment


                          • #14
                            I'm still not convinced dual monitors are valid. Look at the issues flowing a single gun on most aerials. Our single Solid stream requires 210 psi a the inlet to get 1250 out the tip at full height. First one must spec a high flow internal relief valve as it seems many come through with 200 psi as the relief. Next you have to ensure your hose is rated for the supply pressure. We run attack rated 5" LDH just on the tower for these operations, but that limits us to a hand stretch back to the engine. In areas where typical LDH rules the supply beds, exceeding 200 psi will be difficult without lots of thought and planning. Remember dual guns but a single waterway will not make flowing 2000 gpm easy. It would seem that only on properly plumbed quints would this even remotely be viable.

                            Comment


                            • #15
                              I will post this and let it speak for its self.


                              `
                              Attached Files

                              Comment

                              300x600 Ad Unit (In-View)

                              Collapse

                              Upper 300x250

                              Collapse

                              Taboola

                              Collapse

                              Leader

                              Collapse
                              Working...
                              X