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  1. #1
    Junior Member
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    Default 5" INTAKES AND DISCHARGES

    I am inquiring about documentation and testing of LDH intakes and discharges. Question, should the intakes and discharges be on the pump panel side of the engine or on the opposite side? All the pump panels are on the driver's side. Thank you for your help Glenn.


  2. #2
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    Nov 2000
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    Glasgow, KY.
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    Default

    I don't know of any testing or documentation. It is more of a preference (or it works better for us) thing.

  3. #3
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    Default

    Hi Glenn get yourself a copy of NFPA 1901 (1999 version) and the info you are looking for is in there, try ch.14. In ch. 14-7.9 it states no discharge 2.5" or larger shall not be located at the pump operators panel. There is also charts showing what flows/friction losses for a given size intake or discharge. Hope this helps.

  4. #4
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    Food for thought, I have done some calculations on catastrophic failures on 5" LDH . The way the hose is constructed the most likely place to occur is at the coupling. Here a few examples comparing 3" line with 5" line.

    3" hose with 40 PSI at failure = 282 pounds of force
    5" hose with 40 PSI at failure = 782 pounds of force
    3" hose with 70 PSI at failure = 494 pounds of force
    5" hose with 70 PSI at failure = 1372 pounds of force
    3" hose with 120 PSI at failure = 847 pounds of force
    5" hose with 120 PSI at failure = 2352 pounds of force
    3" hose with 150 PSI at failure = 1059 pounds of force
    5" hose with 150 PSI at failure = 2940 pounds of force

    The intake values I have been exposed to are the piston type valve with and adjustable relief valve attached.
    The relief valve is adjustable from 100 PSI to 200 PSI. The other valve is the butterfly which does not a relief valve.

    It is my experience with the piston valve that it must be open slightly before charging the supply line. If this is not done the valve will not open because there is too much force on the valve. If you open the valve slightly the pressure is even on both sides of the valve and it is very easy to open. The first time we tried to use this valve on a hydrant with 120 PSI static pressure we could not open the valve with the handle, but be the ingenious firefighters we are we tried using a pry bar. We were unsuccessful in opening the valve, but we sure broke the handle. A lesson learned.

    The butterfly valve was a problem because our water system is very old we were getting a lot of grit in the valve and this caused serous leaks in the valve. Also this valve does not have a relief valve and this is dangerous when using LDH hose.

    As for using LDH hose when pumping a ladder I believe this is not practical. The LDH hose is tested a 200 PSI and NFPA states you should not pump it over 185 PSI. We did some flow testing on a 100' ladder with a pre plumed waterway, our goal was to flow 1000 GPMs. To accomplish this we had to pump 245 PSI at the base of the ladder to overcome the friction loss, nozzle pressure and elevation. We also did flow testing on our tower ladders to flow 1500 GPMs. To accomplish this we had to pump 245 PSI at the base of the to overcome the friction loss, nozzle pressure, and elevation. This does not include the friction loss in the supply line.

    Please commit
    Glenn

  5. #5
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    Mar 2001
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    Caseyville,IL
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    Default

    From a friction loss standpoint if the 5" is on the drivers side, you will increase your flow when flowing near capacity. On our 1500 2 stage, there was almost 300 gpm diffference between the driver and officers side when flowing 1500 gpm

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