Mixing Rotors and MPs

Discussion in 'Irrigation' started by Duekster, May 28, 2012.

  1. Duekster

    Duekster LawnSite Fanatic
    from DFW, TX
    Posts: 7,961

    So we have discussed that many times Rotors and MProtors can have similar PR.
    If a homeowner changed the landscape impacting one station and only one rotor is now out of place. Would you re-nozzle if needed and then add some MP's or rework the whole station but then you have the over lap concern / transition.

    I suppose I should go start a sketch now :laugh:
     
  2. CAPT Stream Rotar

    CAPT Stream Rotar LawnSite Fanatic
    Posts: 5,895

    If you have the pressure and flow try the re-nozzle first if necessary add the mp's where needed....

    If you can accomplish good watering with minimal changes I always so go for it....Even the chance of that is worth the risk.

    But in DFW im sure that you see dry spots faster and more frequently than we do up here..
     
  3. jvanvliet

    jvanvliet LawnSite Gold Member
    Posts: 3,939

    I'd form a committee to discus it and make recommendations. :p

    You have to train the HO to consult you before making any landscaping changes.:)
     
  4. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,003

    I did an addition by way of changing every spray head in one zone to a Rotator, which freed up flow capacity to let me add/move heads to cover the new territory. Smart for a system that was maxed out in both controller and individual zone flows.
     
  5. Duekster

    Duekster LawnSite Fanatic
    from DFW, TX
    Posts: 7,961

    Definately have to document this move clearly very.
     
  6. Duekster

    Duekster LawnSite Fanatic
    from DFW, TX
    Posts: 7,961



    I often try to do that very often. This is a little different cause I would not save much water, just a better fit because the retaining wall and bed was added. The rotor is blasting the roses. One reason is adding a station triggers the need to bring the POC up to code. :confused:
     
  7. jvanvliet

    jvanvliet LawnSite Gold Member
    Posts: 3,939

    Wait, I want to understand this; every mist head to one rotator? How many mist heads? And how could it free up flow capacity and maintain adequate percipitation?

    I'm not busting bawls here, I want to understand. People try that crap down here all the time, they believe that switching to rotators is more efficient, but don't realize they only have like 40 - 45 PSI static. Flow or not, 45 static is not going to be enough to lift all the heads and procuce the desired throw.
     
  8. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,003

    High static pressure - basement water meter in a home not close to the street - reducing flow is key to improving zone pressure - every spray nozzle gets replaced by a Rotator - pressure nearly doubles in the zone, and that's with the coverage extended to the new lawn area.
     
  9. greendoctor

    greendoctor LawnSite Fanatic
    Posts: 8,951

    What is the lateral size and available volume? The worst systems I have seen were taken from a 1/2" POC, 3/4" valves and 1/2" or 3/'4 laterals with a 45 PSI static pressure. Nothing will really fix that because available volume is only around 4GPM. Flow is useless when the laterals and valves cause further pressure loss. The rotary heads really want 40 PSI at each head to work properly. 25 PSI is the absolute minimum.
     
  10. greendoctor

    greendoctor LawnSite Fanatic
    Posts: 8,951

    I have seen that happen and frequently take advantage of that. The average water meter on residential properties is only 5/8" Static pressure is 75-80 PSI. However maximum safe gallonage through the meter is no more than 15 GPM. It is very common for systems here to be designed to draw 30GPM. Pressure at each spray head is no more than 15 PSI. Cutting the flow down to 10 GPM with a rotary nozzle greatly improves system performance and often saves the lawn.
     

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