Sewage Ejector System question

Discussion in 'Pumps and Wells' started by Robin Whiteside, Oct 14, 2019.

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  1. Oct 14, 2019 #1

    Robin Whiteside

    Robin Whiteside

    Robin Whiteside

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    Location:
    Napa, CA
    I have a country property with septic, that has a downhill guest house. We are installing a bathroom and a toilet. I want to purchase a preassembled sewage ejecter system that can remove waste up to the septic tank. Can you advise me which system fits my need?

    My question regards lateral discharge distances. Due to the design and location, we need to pump laterally 45 feet FIRST, before a 45 degree left turn to a gradual upslope 8-10 vertical and about 140 feet horizontal to the septic. It’s a 10-12 foot vertical rise (from turn to septic). Which system works for that?

    I have installed systems in the past, but we always discharged it straight up FIRST to the line before having the lateral. I’ve never done one with a long lateral distance preceding the vertical slow rise lengthy distance.

    Installed a lot of these in the City, never a long lateral rise to a septic. THANKS,
     
  2. Oct 15, 2019 #2

    Diehard

    Diehard

    Diehard

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    A long lateral rise is only added friction loss based on length plus the height change.

    Assuming you know how to look up friction loss(psi) through pipe based on flow rate, pipe size, length and type.
    To that you would add the equivalent pipe lengths allowance for fittings(check valve, 90's, 45's).

    The total total height to be pumped is based on the vertical distance from the lowest level in the ejector sump to the point of discharge. Rises and falls cancel out each other so only that vertical height difference needs to be included. But it sounds like you'll have a continuous rise to the septic tank anyway, if I follow you correctly.

    For example only: You may have (say 5 ft rise from pit) + 45 ft + 10 ft = 140 ft+ 12 ft = 212 ft
    Plus a couple of 45's and a couple of 90's, a check valve for another 45 ft.
    212 ft + 45 ft = 257 ft.
    257 ft at say 2" PVC pipe at a particular flow rate will give you head loss in PSI or ft of head. To that you add the total vertical height change from beginning to end of 27 ft.
    If your pipe friction lose was say 2.5 psi + 27 ft x .433 psi/ft = 14 psi or 32.8 ft


    You find a pump that has the total head capacity to overcome the friction loss and the height difference at the approximate flow you would want to deliver.
     

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