12" pro spray vs 18" 1/2" nipple

Discussion in 'Irrigation' started by duckworth, Aug 10, 2012.

  1. duckworth

    duckworth LawnSite Member
    Posts: 149

    Well produces 7gpm with 40psi.my question, is there more pressure loss through a 12" prospray with 2000mp or 18" 1/2" nipple with shrudhead and 2000 mp.if there is how much?
     
  2. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,611

    How and where did you take your psi/gpm tests? That is a border-line well. I'd be looking at ALL my friction losses, especially main and lateral lines. Bring the pump guys in and test it for re-charge and drawndown. They might be able to adjust your 60-40 switch and the pressure tank before a stronger pump or a booster is considered.
     
  3. duckworth

    duckworth LawnSite Member
    Posts: 149

    Thanks for the advise ,but l think you missed my main question
     
  4. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,611

    Yup, and for a damn good reason.:rolleyes:
     
  5. duckworth

    duckworth LawnSite Member
    Posts: 149

    I take it there's no pressure loss when pushing 12 " riser up .sorry to waste your time .*trucewhiteflag*
     
  6. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 46,480

    Pressure loss is zilch for the nozzles used with a spray body - A separate value is flow-by, the gpm escaping around the popup piston while the head rises into position
     
  7. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,611

    Which, in my early days, I've had happen, especially with 12" Stream-Rotors and Hunter low-drain check valves. It's not interesting standing there with the client with one's zipper undone and shoes un-tied. :dizzy:
     
  8. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 46,480

    When the Rainbird 1800 with its improved wiper seal appeared, they gave the flow-by as zero. I created a zone of sprays and popup bubblers around a factory, of close to a hundred popups, that proved that the flow-by was definitely not zero.
     
  9. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,611

    I was called into a large commercial site where the LA swore he saw the heads pop-up during the walkthrough and failed afterwards. I could only figure that air in the lines gave enough pressure to pop the heads the first time, the second time the main was full and the heads failed and sat at complete flow-by. That was a good job for us, given the dipwads had not given us any spare wire. payup
     
  10. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 46,480

    In my case, I simply added a second zone valve at a strategic location, and physically cut the zone in two, and ran them simultaneously to designed performance.

    Flow-by was a headache on early popups that used a simple rubber sheet for both gasket and wiper seal, like the first of the toro 570 heads.
     

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