Fresh water syphoning off.

Discussion in 'Tech/Mech General' started by Movin' on, Sep 21, 2010.

  1. Movin' on

    Movin' on

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    When I fill my fresh water tank on my KonTiki 669, if I fill the tank to capacity, the over flow starts to syphon the tank and deposits about a quarter of a tank onto the ground. I've seen this problem written about before on the "net" but I can't remember where. Has anyone else had this problem, if so what's the answer. Adrian.
     
  2. DESCO

    DESCO

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    Not heard of before, but sounds as if the end of the overflow pipe is to low in the tank, or has something attached inside the tank, completing the siphon.


    Dave :thumb::thumb:
     
  3. aba

    aba

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    don't know if this could be related but....
    whilst on holiday in scotland i was talking to a fellow motorhomer as i was filling my tank.
    he said that his had the overflow fitted just above half way up the tank when i queried this he told me "they say its to stop you from filling the tank to keep the loaded weight down below the plated weights"
    now his van was adapted for disabled access and had a wheelchair lift and an oversized hab door so i suppose this could have been altered by the people that adapted the van to recover some of the adaption weight.


    andy
     
  4. dazzer

    dazzer

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    Seal up the end of the overflow pipe!!

    Then fill it to the top of filling neck.......full tank.......end of problem :winky:

    Once the tank is full the excess will come out of the filling neck.
     
  5. Road Runner

    Road Runner

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    My RV does exactly the same thing, can never travel with full tank as alway loose it plus if I fill the bus just past full syphons most of the water away.

    Glad its not only me.
     
  6. ticktok

    ticktok

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    I have a KonTiki 600 and exactly the same thing happens, I to thought the overflow pipe was dipping to far into the tank but when I had a look it only goes in a few mm. Due to the shape of the tank a few liters of water are above this and that is what drains off, it looks a lot but I collected it and it is only a few liters. I intend when I get the chance to put an air vent in the overflow so that it just acts as an overflow and will not start a siphon, the vent will have to be higher than the filler though.
     
  7. carpyone

    carpyone

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    Hi Adrian,

    Were you staying on Walnut Lake a few days ago? As I was emtying my Scout a Swift Kontiki owner had this problem.

    Robert
     
  8. Jim

    Jim Ringleader

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    I have my overflows corked. When I fill up I ensure that I watch it very carefully, and just as the tank looks fit to burst I stop filling. If I dont do this, as soon as the overflo comes into operation (sometimes just bouncing down the road) a syphon is set up and it continues to all but empty the tank.
     
  9. Terry

    Terry Funster Life Member

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    Pull the overflow pipe out so that it is only into the tank 1 ins ( 25 mm ) or so :thumb: If it is a under slug tank just pull it out :thumb::ROFLMAO:
    When we first made the van I let the waste pipe into the bottom of the tank :ROFLMAO: soon found out that it stopped draining into the tank as the water filled it created back pressure :Eeek::Eeek:
    terry
     
  10. aba

    aba

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    looked at my overflow on my tank today.
    it comes out of the top of the tank with a T pipe one of these runs along the top of the tank then out under the van (double floor van) and the other one runs up to a hole in the filler neck as an air vent.
    maybe you could do something along those lines to cure it.:thumb::thumb:

    andy.
     
  11. ticktok

    ticktok

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    You can only cork the overflow if you have a filler cap that breaths otherwise as you use the water the tank will implode! :Doh:
     
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