So fouled up it works

Discussion in 'Irrigation' started by Critical Care, Jun 25, 2005.

  1. Critical Care

    Critical Care LawnSite Bronze Member
    Posts: 1,654

    Remember the term FUBAR, you know, Fouled Up Beyond All Repair? A grounds maintenance client of mine has a FUBAR irrigation system that someone installed several years ago. Okay, this is a small city residential tract home with a front lawn that is only about 1000 square feet but has nine PGPs on it, and all on one zone. The radius of most of these PGPs is only about ten or twelve feet. Does this sound FUBAR to you?

    Trying to figure out what goes here, I started to pop up some of the heads and look at the nozzles. My garsh, some were #7 and #8. I bet that the flow rate demand is double that of what is actually available. What’s funny about this is that the system in its FUBAR way actually does water the lawn... sort of.

    I suppose that the designers of this system thought, “Short radius? No problem, just keep throwingin larger nozzles and more heads until the radius drops."

    Is this must be the new method of handling all sites, big or small, with one type of rotor?
     
  2. sildoc

    sildoc LawnSite Silver Member
    Posts: 2,925

    Seems funny but I have 3 homeowner installed and 2 commercial installed accounts like that. 1 has 7 RB 1800 series all with 1/2 or more. This is covering right at 600 sq ft. I set it at 3 min at 100 degrees temp EOD. dang near floods the neighborhood at that. PSI at Main line is max 90 and min 65. Heck has the nicest lawn in neighborhood.
    Don't get me started on the so called commercial guy that put 15 Hunter PGP's with #6 nozzels in on one zone to cover 1800 sq ft. Luckily this is a commercial account that is over 10 yrs old. I am guessing when he installed the well was producing well and had a good pump. Now pump has been replaced and well only puts out 15 gpm.

    Now figure a drip system out for me.
    almost 400 drips at 1 gpm???
    Ok now the farthest one still puts out.
    I have since started changing them out to .5 and less, and water for longer but still, what the heck????
    Just amazing what you find out there.
     
  3. DGI

    DGI LawnSite Member
    from SE Mich
    Posts: 173

    I recently bid an addition to a garden zone. We installed a valve and feeder there a few years back. The house has a shallow well for the irrigation with a 1.5hp pump. A 1.25" feeder was stubbed up near the garden, which the homeowner hook up to. He piped it all out with 3/4" black steel pipe, installed with a backhoe, even though I sold him a roll of 1". The 4 heads weren't tossing like he thought they should, so he reduced the main feeder off of the 1.25" to .5" -- "to get more pressure" -- which didn't exactly do the trick. I didn't know any better, and bid the job at $350 for 2 5012s, which I figured would need about 30ft of hand trenching. Turned out to be more like 100+ and took 3 guys 3 hours. They had to get the water for the heads from where the feeder was, rather than tapping the lateral. :realmad:

    Having replaced the existing "manifold" with 3 different connections off of the 1.25" poly, the heads were shooting 40+ off of their risers. Now that they weren't tinkling, they were going "too far" into his unmaintained area. With the screw turned down on the nozzle, they were "misting way too much." I had to change out all of the nozzles to low angles.

    :(
     
  4. fixer67

    fixer67 LawnSite Silver Member
    Posts: 2,098

    That reminds me of a brick mason I worked for once. On most of the new construction the water pressure would be so high it would blow the garden hoses he was using. So he thought that if he just barely cracked the valve the pressure would not get up so high. He could not separate GPM from PSI. I had to buy a pressure gauge and show him that even a dripping valve would still built up the same pressure it just took a bit longer.
     
  5. Critical Care

    Critical Care LawnSite Bronze Member
    Posts: 1,654

    Well... I'm glad I'm not the only person that runs into these "weird installs". Hey, and along with trying to educate people on the differences between GPM and PSI, lets also include CFM. I can't tell you how many times I've run into guys that say that their shop air compressors do great jobs for blowing out their irrigation system because they can be cranked up to 120 PSI.

    Heh heh, this makes me think of an old movie where a couple rock musicians were comparing their different guitar amps. One guy claimed that his amp was better because the numbers on his amp's volume control went up to 9, while the other guys amp only had numbers going to to 6. These would be the same guys that would think that a better irrigation system would have more sprinklers than the one next door.
     

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