Discussion in 'Irrigation' started by xclusiveTN, Oct 16, 2013.

  1. xclusiveTN

    xclusiveTN LawnSite Member
    Messages: 8

    I had a few questions if the professionals could help me with I would greatly appreciate it. I have read thru the forums but don't see a definitive answer for my questions. I have 5/8, 3/4 meter and my sprinkler system pretty much designed but I am not sure of a few things:

    1. I have a large front yard and wanted to use mp's for the precip rate but it would be less heads for sure if I went with a small rotor. When designing systems do the pros design for looks or the most efficient? My front yard is 80x40 rectangle and I want to know is it better to choke down mp3000 or hope that the mp2000 does as it say and will reach 20ft. There is about 4ft elevation change between the front of the yard at the street sloping down to the house.

    2. I have 80psi water pressure (even had the city come out and check it as well to verify). I live in a cul de sac so no more houses will be built on our street. It it better for me to get a pressure regulator off the water meter or should I buy individual pressure regulator bodies for the mp's I will be using? What pressure regulator would you recommend? What body would you suggest I use with the mp's?

    3. Do you normally design the main line (pvc) for the shortest length possible. I would like to put my backflow prev on the side of the house out of view but in order for me to do that my run will be approx 150ft. Is this still ok for 1in pvc (the rest of my system will be poly) or would you recommend increasing my mainline size?


  2. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    I wouldn't bet on the MP2000 hitting 20 feet reliably unless you have a nozzle pressure of 50-55 PSI. That said, you might be able to hit it with a RB 1806-SAM-P45 (regulated @ 45 PSI) and the MP2000.

    If you can't get it done with the MP2000 then your only choice with the MPRotators would be to put the MP3000 on a RB 1806-SAM-PRS body (regulated @ 30 PSI) and adjust down with the radius screw.

    Doesn't matter if no more houses are being built in your cul-de-sac. If there are houses still being built that uses the same city main as the one that serves your cul-de-sac then there is a potential loss of static pressure.

    80 PSI is too high for house plumbing and fixtures and IMO it needs to be regulated down. For your irrigation I would shoot for something in the 50-60 range at the valve as it sounds like you are on a postage stamp lot. Personally I would regulate them independently (house and irrigation supplies).

    What body to use .... see question 1.

    Don't worry about it. 1" will most likely be fine, but you need to crunch the numbers to be certain.
  3. cjohn2000

    cjohn2000 LawnSite Senior Member
    Messages: 570

    I have never had much luck adjusting down MP2000's with the radius screw. Factory says they can be adjusted down up to 25%. MP corners adjust down okay.
  4. bcg

    bcg LawnSite Bronze Member
    from Tx
    Messages: 1,865

    If it were me, on a 40 x 80, I'd be using 5000 series rotors with low angle nozzles. MP's are great when you need to solve a problem but if you can use rotors, use them. It's easier and they're just as efficient.
  5. xclusiveTN

    xclusiveTN LawnSite Member
    Messages: 8

    Thanks for your responses, I really do appreciate it!

    Do the 5000 series adjust down easily? I thought about doing a rotor and if I could find one to hit 40ft with no problem I would have fewer heads to put in and I wouldn't have to deal with any 360 heads.

    Thanks! :dancing:
  6. bcg

    bcg LawnSite Bronze Member
    from Tx
    Messages: 1,865

    RainBird shows 40' with a 3.0 nozzle in the 5000 at 45 PSI ( If you use 3.0 on the corners and 6.0 for the 1/2 circles, you could do it with 6 rotors. You'll need to split it into 2 zones though, 12GPM is about all I design for through a 5/8 meter, you can push it to 15 - 16 but it's better not to.

    Adjusting the distance on a 5000 is as simple as screwing the nozzle set screw in further. There's a limit to this, you don't want to dial it down more than about 20% - 25% or you're going to really mess up your pattern but it'll work for your needs.

    It just so happens that the PRS version of the 5000 is set for 45PSI so that would be the ideal head for your design.
  7. jbell36

    jbell36 LawnSite Bronze Member
    from KANSAS
    Messages: 1,416

    here's what i would do...

    first, to answer your questions.
    1. design for efficiency or looks. i like to do both. efficiency comes first, tho. i hate when a system just doesn't look right. my last system looked like a perfect grid, for the most part, all heads in a row. one thing to note, no system is ever perfect, you will never get a perfect design and in most if not all situations it's not a perfect square or rectangle.

    2. 80 is a high psi but nothing i haven't seen. kiril is right, 60 is more around where you want to be. i would say more around 100 is where problems are inevitable, so you are kind of in the middle

    3. i like to try to find the shortest length for the mainline, but your wire runs with it and you have to find a location for the controller and sometimes that's all the way around the house. shorter mainline can equal less potential problems. i would suggest a master valve as well, i usually put those in on any system larger than 2 or 3 zones, which is usually most systems, but using MP's uses less valves/zones

    As far as design goes, i like to use mp's. I think you can get away with MP2000's on this system for sure, BUT i would suggest using the regular spray heads and not the press. regulated ones to get the distance. i would never recommend that, but in this situation is makes sense. i have found out that you simply can't adjust the nozzles down at all on a regular spray head, but if you put a press. regulated head in, you can take it down 25%. i love MP's, and on this system i would use MP2000's, 4 90's, 8 180's, and 3 360's (make a grid). this gives you a flow rate of 11.93 which is safe for a 5/8 meter, AND you can do it all on one zone. 15 MP's look cool when working all at once. longer run time, but you also have less zones, so it more or less cancels each other out. be sure to use a pressure regulated valve tho so you can have some control. keep in mind the 11.93 is rated for 40 psi, not 60 like your operating pressure would be (after back flow). hopefully you can turn the valve down and keep your distance, giving you a safe GPM
  8. jbell36

    jbell36 LawnSite Bronze Member
    from KANSAS
    Messages: 1,416

    if you want to do rotors, i don't know, i wouldn't suggest shooting 40 feet. i would design it the same as i designed the mp's...i know the idea of only using 8 heads sounds better, but it's prob going to be at least 2 zones if not 3, i haven't looked at the numbers
  9. jbell36

    jbell36 LawnSite Bronze Member
    from KANSAS
    Messages: 1,416

    also, i'm not very familiar with the rainbird heads/versions...very well could be a better option, never looked into them
  10. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,758

    Designing for a 40-foot spray radius is stretching it, unless you got some long-throat brass impact heads.

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