Dole flow control valves

Discussion in 'Pumps and Tanks Well Forum & Blog' started by Arky217, Feb 4, 2014.

  1. Arky217

    Arky217 New Member

    Messages:
    43
    Location:
    Arkansas
    The driller that drilled my well said the output was approximately 5 gpm.
    ( Well is 115' in a 6" casing, static level at 57')

    I'm planning to put in a Dole flow control valve before the pressure tank tee to prevent the pump from pumping more flow than the well's rated output.

    My water usage is very conservative, rarely more than 1 fixture in use at a time, so I can't forsee using water for anything at a rate of more 2 or 3 gpm.

    So, I'm wondering, should I go with a 5 gpm or should I go with a 3 gpm in case the well's output is somewhat lower than 5 gpm ? (pressure tank drawdown will be 9.4 gal.)

    Anything I'm overlooking if I go with a 3 gpm instead of a 5 gpm, such as an adverse affect to the pump ? ( pump will be a 7 gpm Goulds, 3 wire, 115v, model # 7GS05411C )

    Thanks,
    Arky
  2. VAWellDriller

    VAWellDriller Member

    Messages:
    171
    Location:
    Richmond, VA
    It won't hurt the pump, but you'll be shorting yourself of water if you ever do need it. With the demands you've said, you don't need to put anything to restrict the flow with that pump and tank. Don't overthink it too much.
  3. valveman

    valveman Moderator Staff Member

    Messages:
    4,586
    Location:
    Lubbock, Texas
    VA is right. With a 57’ static level you have about 75 gallons stored in the well that you can use at any flow rate, on top of the 5 GPM recovery rate of the well. So you could use 10 GPM for about 10 minutes before the well is down to 5 GPM.

    If you put a 3 GPM Dole valve on it and are trying to use 4 GPM, you will think the well is dry because the pressure will drop to nothing. Same thing with a 5 GPM Dole valve when you need 6 GPM or more.

    I would put in a 10 GPM pump so I would never lack for pressure. Then all you need is a Dry Well protection device like the Cycle Sensor at this link.

    http://www.cyclestopvalves.com/prod_sensor.html

    That way if you do use all the water in the well the Cycle Sensor will shut off the pump. It can be set to automatically restart the pump from 1 to 500 minutes after a dry well condition. With 5 GPM recovery rate you could set the Cycle Sensor to restart the pump in as little as 5 minutes, and you would be back in water.
  4. Reach4

    Reach4 Well-Known Member

    Messages:
    2,806
    Location:
    IL
    http://store.kgpowersystems.com/goulds.gs.notes.pdf shows 7GS05 supplying 10 GPM at 150 ft head. The 10GS05 says it will supply #11.5 GPM at 150 ft head. I see the 7GS05 would be better given his load and well capacity estimates.

    It seems to me that the 10GS05 would fill his pressure tank too fast... Hmm......

    Arky217, note the recent discussions on measuring the water level with just a 1/4 inch tube down the well bore accompanying the wires, a tire pump and a gauge. Seems to me that the well digger's rating could differ from what the well does over time.
  5. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,512
    Location:
    Houston, TX
    The Cycle Sensor would be nice if it fits into your budget. Would be worth the money.

    Will it work OK with a Gen Set ? I would think so.


    Good Luck
  6. Arky217

    Arky217 New Member

    Messages:
    43
    Location:
    Arkansas


    Ok, I think it's becoming a little clearer to me.

    The main reason I was considering the Dole flow control valve was that if I ever needed a continuous water flow (such as trying to put out a grass fire for example), that it would prevent me from pumping the well dry.

    But I forgot that in my worse case flow senario ( 60 psi cutoff pressure with the static water level just above the pump ), the total head would be 250', in which case the pump would only be pumping at about 5.75 gpm anyway.

    (With the pump at 100' feet down, I figured total head would be 100' + 4' (elev. change) + 8' (friction loss thru my piping @ approx. 5gpm) + 138' (60 psi cutoff press.) for a total of 250')

    As to a 10gpm pump, even if I lowered the pressure from 40-60 to 30-50, it looks like the worst case total head would fall outside of the pump curve.

    At the link you mentioned for a cycle sensor, it looks like they don't offer a model for a 1/2 hp, 115v pump.

    "The Cycle Sensor is available in three models:
    Model CS1PH1-2HP works with 230V single phase pumps from 1/3HP to 2HP,
    Model CS1PH3-15HP works with single phase pumps from 3HP to 15HP, and
    Model CS3PH1-500HP works with three phase pumps from 1HP to 500HP."

    Are other models available somewhere that would work with a 1/2hp, 115v pump ?

    Or, like you said, I'm just overthinking it and maybe I should just use a low pressure cutoff pressure switch and call it good.

    Thanks,
    Arky
  7. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,512
    Location:
    Houston, TX

    I think you may be over thinking, but you sure have done your homework. Nice Job.

    I use a low pressure cutoff switch, and they work great, if they are easy to get to and you do not mind a blister on your thumb. Anyone that has used one knows what I am talking about. They can be a pain in the thumb to reset.

    Power failures can be a nuisance if someone or something uses water during a power outage.


    Good Luck
    Last edited: Feb 5, 2014
  8. Arky217

    Arky217 New Member

    Messages:
    43
    Location:
    Arkansas


    Regarding pump protection with a low pressure cutoff switch, as to the other end of the spectrum, have you ever occasioned the contacts of a pressure switch to 'weld' shut after a duration of continuous arcing ?

    If that were to happen, I imagine that the pump would continue to run, pumping through the relief valve.
    If that condition were not noticed (say the relief valve outlet was piped outside for example), then I suppose that the well might be pumped dry and the pump damaged.

    I was considering using another regular pressure switch wired in series with the low cutoff switch.
    Its pressure would be set at 45-65 and would always remained closed unless the contacts of the low cutoff switch 'welded', then the extra switch would open at 65psi.
    Thereafter the extra switch would function as the normal switch until the low cutoff switch could be replaced.

    Then a relay could be powered from the downstream or pump side of the extra pressure switch, and a normally closed set of contacts of the relay could operate a buzzer that would alert you to the failed condition of the low pressure cutoff switch.

    Or, is this condition so rare that such a setup would be totally unnecessary ?

    ( Again, overthinking too much, I know )

    Thanks,
    Arky
  9. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,512
    Location:
    Houston, TX
    Yes I have seen contacts weld shut like that.

    The chances of a 1/2 HP motor welding the contacts together on a 2 HP rated switch would be Very Very rare.


    Are you a worrywart ? lol
  10. valveman

    valveman Moderator Staff Member

    Messages:
    4,586
    Location:
    Lubbock, Texas
    Yes the Cycle Sensor comes in 115V for a ½ HP pump. But we don’t sell many of them because most people use 230V for well pumps.

    If the pump will only make 5.75 GPM at 60 PSI, then if the pressure relief pops off at 75 PSI, the pump will only be putting out about 3 GPM, so it won’t pump the well dry.

    A Cycle Sensor is better than a low-pressure kill switch, especially when you have a large pressure tank. If the well is pumped dry while trying to refill the pressure tank, the pump won’t go off on low pressure. But the Cycle Sensor will still see low amps and shut the pump off.

    A pressure tank is just an additional load on a weak well. If you use a small 4.5 gallon size tank with a CSV, the tank is not an additional load.

    Even if used with a large tank, a CSV will only refill the tank at 1 GPM, so the well won’t be pumped dry while filling the tank.
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