Hunter PGP spacing

Discussion in 'Irrigation' started by sod, Jul 1, 2007.

  1. sod

    sod LawnSite Member
    Posts: 13

    They are completing reconstruction the street is front of our house so I now have to reinstall the sprinkler system along the new curb line The road layout changed so the system also needs to be redesigned to refect the new lay out.

    I always thought the previous head locations were too far apart (toro heads) for maximum coverage. I will now be putting in hunter pgp's instead of the old toro heads which I never liked from day one because they are so user unfriendly.

    Our system is on the city water system with a 35-40 gallon per minute water pressure. The lines are 3/4" feeders. What would you recommend for spacing the heads?

    Also, because of the road layout change I need to put an additional head in one zone. The zone I'm considering currently has five heads. The heads are each feed with a there own seperate 3/4' lines coming from the mainline at the valve box area to their respective curb locations. Do you think it adviseable to just add an additonal line off of one of the current seperate lines to feed this new head.

    Thanks for the help. It should be fun trying to get new sod to go in this heat. Add the draught were are experencing here in the Twin Cities, I figure the timing couldn't be worse. :usflag:
  2. Definitely need pics and yard measurements to really be good help for you.
  3. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    As FM noted... sprinkler head spacings depend on zone plot plan, PSI at the sprinkler heads and nozzles of the sprinklers used. Also, depending on which nozzles are used and what type/schedule/class, etc. of lateral line piping is existing you may, or may not be able to install two sprinkler heads off one 3/4" lateral. The more water you run through a section of pipe the more friction is encountered. If that GPM/friction/speed of the water exceeds the recommendation for the specific piping then ultimate pressure/performance at the sprinkler head(s) is affected. Depending on pressure/GPM at the sprinkler head... this deficiency can also back up along all piping into valve and main line performance where you may exceed the total zone GPM.
  4. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,799

    You mean 35-45 PSI right, you aren't pushing 35-45 GPM through 3/4" lateral lines :)

    As far as adding the additional head, calculate how many GPM the heads on that zone are using (Find out the nozzle size and look it up on the chart).

    If you ca renozzle the zone to match the same GPM as it had before the new head, and still get head to head coverage, then you can add another head to it.
  5. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,722

    ....and my pickup truck's mileage is 300 foot pounds. :p
  6. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    Damn New Yorkers... I only get 275. :laugh:
  7. sod

    sod LawnSite Member
    Posts: 13

    I will post pictures when the light is better. Sorry, I did mean 35-45 psi, but I'm glad to give you boys a laugh. I am also reading Jesse Strykers' site which is very informative. Thanks
  8. drmiller100

    drmiller100 LawnSite Senior Member
    Posts: 562

    a 3/4 line is perfectly capable of handling the water of 2 pgp's as long as the run is under a 1000 feet or so.

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