Ppo ups don't pop up all the way???

Discussion in 'Irrigation' started by CRUZMISL, Aug 25, 2004.

  1. CRUZMISL

    CRUZMISL LawnSite Member
    from zone 6
    Posts: 186

    HI All,
    I had replaced a poorly designed system with RainBird1804 pop up's and MP3000's. There are 4 heads per zone and on one zone in particular the GPM is 11.83@40psi. The system runs at about 42psi so the gpm may be slightly higher. The supply is 3/4 copper going to 1"poly. The maximun GPM of 3/4 copper is 10gpm. All other zones are less than 10gpm. Are the heads not popping up all the way since I am slightly over the max capability of the system or is it normal? They pop up about 3 inches but I can lift the riser to get full extension. Once it's fully extended then they stay up. Suggestions or thoughts? FWIW, they appear to be irrigating fine with no dry or missed areas.
    Thanks,
    JOE
     
  2. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    Could be that you are stretched on GPM. One possibility is, let's say you have 4 heads with 15' nozzles in them. Can you change the nozzles to 12' or 10' and still get proper coverage. The shorter the radius, the less GPM the heads will put out.
     
  3. the gpm is probably higher than what you think.....many factors can contribute to that including....design of system. My guess is that you are running more gpm than you think.....bummer.
     
  4. DGI

    DGI LawnSite Member
    from SE Mich
    Posts: 173

    How are the heads throwing?
     
  5. CRUZMISL

    CRUZMISL LawnSite Member
    from zone 6
    Posts: 186

  6. Instant Rain

    Instant Rain LawnSite Member
    Posts: 54

    how old is the system? sometimes an old valve that is starting to fail will become a major restriction and cause an abnormal pressure drop this can be fixed by replaceing the diaphram with a new one. i can't say that the station is flowing so many gpm that you have burned away your pressure since i dont know the lay out of the pipe. with good static pressure and a good design a gallon per minute over the recomended flow probably won't hurt the operating pressure. generally those recomendations are in place as a speed limit to lessen the forces that moving water may put on the pipe and fittings.
     
  7. DGI

    DGI LawnSite Member
    from SE Mich
    Posts: 173

    You could gut the valve and try running it that way. The first posters are probably right, though. It's stretched to the limit.
     
  8. CRUZMISL

    CRUZMISL LawnSite Member
    from zone 6
    Posts: 186

    The system is about 7 years old and is comprised of 1" poly fed by city water. I'm thinking it may be stretching the capabilities of the system but will look into the valve option as well.
    Worse case I can block a head and see if it helps. If it does I have to add a zone anyway so I can add the single head to the new zone.

    Joe
     

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