irrigation pipe

Discussion in 'Gardening & Plant Propagation' started by bbbuddy, Apr 29, 2005.

  1. bbbuddy

    bbbuddy Well-Known Member

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    hi, I have a well that puts out 42 gpm, will do so 24/7. One horsepower submersible well pump. I want to irrigate some pasture and grains with impulse sprinklers, enough to match the well output pretty closely, like 8 sprinkler heads using 5 gpm at about 40 to 45 pounds pressure.

    All of the places I want to irrigate are downhill from the wellhead, anywhere from 2% to 10% grades.

    The pipe runs will be 400 feet to 1000 feet long, all downhill.
    I can't seem to figure out what size pipe I need. Each place I look says something different. Same with talking to people.
    It seems to me that the pipe friction will be more or less negated by the negative head, am I right?

    I plan to move the sprinkler heads around to cover more ground, maybe 6 acres total. Thought maybe having permanent pipe runs along fence lines, with quick connects for short lengths of hose to the impulse sprinklers, which would all be grouped in one area at a time...
    it is the long permanent runs I can't figure out, and don't want to buy a bunch of pipe only to find it is too small!
    thanks, maddy
     
  2. Windy in Kansas

    Windy in Kansas In Remembrance

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    I can't offer anymore than my opinion since my "Pocket Ref" book doesn't give enough information.

    Even with negative head it will take a pretty good pump to continually discharge 42 gpm through nozzles at 40 to 45 psi. I am of the opinion that building up the pressure within the pipe will negate the gain from the negative head. Because of that pipe friction comes back into play.

    It will take someone more skilled or with a better reference than I have to come up with the correct answer. However I am of the opinion that you will have to have a booster pump to keep up that many gpms and psi.

    I checked into a big gun sprinkler on a self winding hose real for a 35 gpm pump, i.e. a small irrigation system like a football field would use. I was told that the nozzle would indeed require a booster pump in order for it to work.

    Sorry that I can't offer more.
     

  3. james dilley

    james dilley Well-Known Member Supporter

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    Have you thought about furrow irrigation?? or using borders and flooding the area with water to the depth you require?? that might work better for you.
     
  4. bbbuddy

    bbbuddy Well-Known Member

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    Jul 29, 2002

    No, I would prefer to sprinkler it...uses 1/2 as much water, (Or...I can irrigate twice as much land)
    and I don't have to re-contour the land...up and down, hills and gullies...nothing steep, but nothing that would lend itself to flooding

    thanks, maddy