max flow for 50mm pipe

Discussion in 'Pumps and Waterflow' started by RiaanP, 11 Oct 2009.

  1. RiaanP

    RiaanP Moderator

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    What is the maximum flow that 50mm pipe can handle when used for overflow?
    So where the flow is not pressurized or pumped, just flowing under gravity.

    I done a test yesterday, using a lot stronger pump in the sump. What I found is that everything do balance out but the water level in the display did rise with more that 10mm and my sump run emptier. so the water height above the overflow increased.

    When I run both my old return pump and the stronger one, the effect was more. Display level increase more, sump even more emptier, and the height above overflow was about 30mm. This increase in display tank water level obviously do start to put pressure on the overflow pipe, forcing a higher flow.

    So to ask same question differently.
    What should the flow rate be for a 50mm downpipe to allow water level to be maximum 5mm higher than overflow pipe?

    Thinking more about it, it got to do with the length of the overflow area. Shorter area will have higher "head" and a wider area a lower "head" height. So how do you calculate the overflow width?
     
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  3. butcherman

    butcherman Moderator MASA Contributor

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    is the overflow runnig straight down or are there bends in the pipe?
     
  4. Drk

    Drk

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    If there is a 90 bend in the pipe it will reduce the waterflow i run 4000 l/h in mine with no problem but have a 90 bend in.
     
  5. RiaanP

    RiaanP Thread Starter Moderator

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    Yes there are 90 degree bends.

    But I think the flow is dependant on the overflow length. There for the lower the water height above the overflow rim.

    So how do you calculate the overflow length?
     
  6. IMarine

    IMarine

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    Hi Riaan i run a lagauna 7000lt return pump with a 50mm pipe to my display and with a 32m durso with 2 outlits into my sump with no problem
     
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