MP Rotator vs Single Stream Rotor

Discussion in 'Irrigation' started by txirrigation, Aug 6, 2011.

  1. txirrigation

    txirrigation LawnSite Senior Member
    from Texas
    Messages: 977

    What do you guys think?

    In my experince many customers end up running the MPR so much longer that the water savings by the design goes null. Seems like I also get more coverage complaints on the MPR's. I space the 3000's @ 25', 2000 @ 17' (although they are pretty good at 20), and I do not use the 1000's bc they dont work that great.

    Also if the customer does not keep the grass cut, the grass blades KILL the MPR streams while the single stream seems to perform OK in long grass. Although the grass should be cut to keep it under the riser hight, we all know the "I mow once every 3 weeks/month customer." Then they wonder why the grass is soooo grean by the sprinkler head, and dead out in the yard.

    All this being said, the MPR definitly has advantages. If the customer cuts the grass and understands the concept, they will have much more uniformly green grass with the MPR.

    I always try to gauge the home owner before I suggest one or the other.
  2. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,334

    Not following you? A single stream rotor PR rates will generally be close to or considerably lower than the MPR for a comparable radius which means longer run times than the MPR.

    I also fail to see how the water savings go out the window. Higher distribution uniformity is what it is. Anything that affects the performance of the MPR will affect the performance of a single stream rotor equally or more so, with the possible exception of plant blockage.

    I use them all, 1000 - 3000 and have no complaints with coverage. If it is a design issue, the MPR can make up for some of the deficiencies, but it isn't a magic bullet either.

    Then use 6" pops or cut down on the water and ferts so it doesn't grow so fast if you are only cutting once a month.
  3. GreenLight

    GreenLight LawnSite Senior Member
    Messages: 526

    I always hear the "longer run times needed" for mp's vs standard rotors and I still don't get this. Every performance chart I have ever seen says the MP is a close equivalent per radius @ 40 psi to a RB Standard angle 4.0 and a Hunter (red nozzle) 7. Those are both fairly high distribution rate nozzles for residential apps and the MP is about on the same precip rate as both (roughly .4 inches per hour).

    I will agree, that I believe you have to over spray edges a bit with mps as they put out a bit of a false radius as they open up and die off.
  4. txirrigation

    txirrigation LawnSite Senior Member
    from Texas
    Messages: 977

    The edges are irritating! To pass an inspection nothing can land on hardscapes, but to get good coverage throughout the throw you have to spray on the hardscape.

    Kiril- I am doubting your real world knowlege. Just because it says so in the books, doesnt mean it is so in practice. When you are using the single stream they put down water much faster in the area that the water is landing. Meaning when your using a #7 in a pgp you are putting 3.5 gpm in one stream. With the MPR 3000 you are spreading the 3.14 gpm over many different streams.

    Although the book may say different we consistantly have to run MPR's 4-6 min longer to get the same result out of a PGP, 5004, i-20 etc. What I mean by the same result is, green grass.
  5. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,749

    I run single-stream rotor zones far longer than stream rotor zones.

    (probably because I space PGP heads ninety feet apart :p)
  6. mitchgo

    mitchgo LawnSite Silver Member
    Messages: 2,955

    Mpr's rotator and the toro precisions uniformity is unmatched compared to a rotor head.

    It's claimed you only need 30% overlap on a mpr zone and achieve the same results of a head to head back to back rotor zone due to the uniformity

    Mpr's do run longer then rotors because they use less water.. In a way they do use the same amount of water however the water is being applied much more effeicently

    They all have there places
  7. GreenLight

    GreenLight LawnSite Senior Member
    Messages: 526

    Sorry, I know it's argumentative, but really this isn't altogether true. MP's use less water because they don't have as large of a radial pattern as a true standard rotor in most cases.

    Every mp has a higher precip rate than RB standard nozzles until you get to the 4.0, based on 45 psi.
  8. rlpsystems

    rlpsystems LawnSite Senior Member
    Messages: 472

    Mitch is right..... they have there places .... and thats it. Its kinda funny at how they use a third less now a one hour run time turns into a 3 hour run time
    Field experience means more to me than a pamphlet brochure or a book from the designer
  9. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,334

    I'll be equally as argumentative and say it isn't about radius at all, it is about distribution uniformity.
  10. txirrigation

    txirrigation LawnSite Senior Member
    from Texas
    Messages: 977

    Back to the topic. Which do you guys prefer?

    For a while I was a MPR guy, after 175-200 systems with them I think I am going to move back to the PGP/5004

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