Hunter PGP or Toro 570's

Discussion in 'Irrigation' started by surge, May 9, 2005.

  1. surge

    surge LawnSite Member
    Messages: 21

    I am installing a sprinkler system for my parents in the next few weeks and I have a few questions on sprinklers.

    I have been doing research on sprinkler heads and here is what I have narrowed it down to. Either putting in the Toro 570's or the Hunter PGP.

    I have a 27 x 27 section of land that I need to put sprinklers in. With this area, I can either put in 4 Hunter PGP in (one in each corner), or 9 Toro 570's(one in each corner, one on each side, and one in the center).

    So here is my question. Which one of these heads is more reliable and durable. I ask this because my initial response would be the Toro's. This is becasue the Toro's are basically a closed system. The body itself is just a hollow tube, and then the nozzle screws in. In terms of durability for the Toro 570 the only thing I can see replacing is the nozzle itself. However, I am worried if I use the Hunter PGP, that eventually the rotor will break and I will need to dig up the head to replace it. We have really hard water as well so I am thinking that over time the calcium would build up on the gears and it would need to be replaced as well.

    I would prefer to use the Hunters because it will require less trenching, pipe laying, and time than the Toro's. But I would be up for putting the time in now to do it right vs putting time in later digging them up to replace them. Basically I am looking to put in the least amount of maintainence and money into the system once it is up and running.

    If anyone has any thoughts or knows what the average lifespan of these two heads are, I would definately appreciate it.


  2. Broker

    Broker LawnSite Senior Member
    Messages: 382

    I would use the PGP's but I am biased.
  3. bicmudpuppy

    bicmudpuppy LawnSite Silver Member
    Messages: 2,781

    Use the PGP's if that's your prefered rotor. Spray heads go bad at the same rate or possibly faster than rotors. The rubber seal on any pop up wears out long before the gears will. This means you have over twice the seals with pop ups that you do with rotors. Also, your precip rate with sprays will be in excess of 2"/hour. With rotors and the area described, you have the option of nozzling for as much as 1" per hour and as little as .25" per hour. I like slow precip, but most of the yards I see are heavy clay and a slow precip works much better.
  4. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,377

    For a plot that small, you could put in Toro 300 series stream rotors in the corners.
  5. surge

    surge LawnSite Member
    Messages: 21

    So from the above consensus, it looks like durability of the pop-up vs the rotor is about the same? Is this correct? Under ideal conditions how long will a typical PGP or pop-up last before it needs to be replaced?

    Has anyone had any problems with the rotor gears jamming up due to hard water?

    Can the seals be replaced without having to replace the sprinkler head itself? If you have to replace the whole sprinkler when the seals go bad on pop-ups, then replacement labor cost is a wash between the rotors and the pop ups, so it is really a matter of preference......
  6. jerryrwm

    jerryrwm LawnSite Bronze Member
    Messages: 1,274

    Spray heads given the choice. With a spray head system, you are not as affected by the wind while trying to get water all the way to the edges. It is true that your precipitation rate will be higher than with the rotors, but that is controlled by the time per zone. You can water to get 1"/wk and only need to water less than 30 minutes per week. 15 minutes twice a week. If percolation is a problem, cut the water times down and allow a rest period and then water again the same night. Now you can water for 7 or 8 minutes twice and still get the water you need.

    PGP's will work fine in that area also, but again if wind is a factor you will not keep the water inside the borders. And if using the PGP my recopmmendation is throw the #1, #2, & #3 nozzles away. Any wind at all and they are useless.

    As far as replacing seals, normally this only becomes a factor after a number of years. There are still plenty of 20 yr old spray heads in the ground and still working well. And if a seal does go out, just replace the whole body - $4.00 for a 570-Z4P and reuse the nozzle. PGP rotors same thing. 10 yrs is not unreasonable life expectancy.

    Jerry R
  7. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,377

    If you'd only asked this a decade ago, you could have used a single Rain-Jet square pattern head in the very center of your plot, and saved even more digging.
  8. Dirty Water

    Dirty Water LawnSite Fanatic
    Messages: 6,794

    Have you measured your Gallons Per minute, and PSI?

    9 Spray heads will be using a lot of GPM. You'll probably have to divide it into 2 zones.

    I would reccomend 5 PGP's for this job, but I would not put them in the corners. Instead I would put them in a diamond pattern, like this:


    The reasion for this, is because if you put the heads in the corners, you will only end up with single coverage of the grass area by each head, and a dry spot in the middle. (unless all the heads overshoot, then you'll have quadruple coverage in the middle).

    Look at the coverage you get when you put the heads in the layout above:


    The Blue area's are being covered by two sprinklers, the red area is being hit by two border sprinklers, and the 360 degree sprinkler in the middle. You won't have a single dry spot if you do it this way.

    The middle sprinkler is pretty optional in a yard this small, having the four in a diamond would ensure double coverage of all areas, and most likely be adequate.

  9. Dirty Water

    Dirty Water LawnSite Fanatic
    Messages: 6,794

    Eh, won't let me edit. Something I didn't mention is that the green area is getting single coverage, but the amount of single coverage is significantly less than if you put the heads in the corners.
  10. surge

    surge LawnSite Member
    Messages: 21

    Two questions.....

    1) In your second diagram with the colors representing the coverage. Unless I am mistaken the green sections show single coverage. I thought you always wanted at least double coverage.

    You are correct with the overlapping coverage I was planning on with the 4 corners. My area is 27x27 so I was going to set the radius at about 28 feet so I have 1 foot of overlap. You are also correct, the very center would have quadruple coverage, some would have triple coverage, but the majority would have double coverage and and no single coverage areas.

    2) Hypothetically if I were to use the diamond configuration, the PGP can't go down that low can they, you are talking about a 13 1/2 foot radius (27/2). I thought the shortest distance these guys would throw is 22'. Am I wrong?

    3) I did a static pressure test and I am currently sitting at 70 psi. I have 3/4" pvc going from the water main to the house. I haven't done the gallons per minute test, but according to Hunter's websight, I cross-referenced my pipe size with my static pressure and supposedly I will be sitting at 10gpm with a working pressure of 50psi. That is according to their website.

    4) You guys are correct, if I use the toro 570's or any other spray nozzle for that matter, I will have to cut the yard into two zones with two valves. Not that big of a deal though. A little more upfront work.

    5) I don't think wind is too big of a factor. I plan on running them in the morning when the wind is pretty non-existent. Speaking of which, when do you guys program them to come on at? I was thinking around 5am, that way they are done before anyone leaves for work, but at the same time late enough so it doesn't weight down the grass and cause fungus problems. Just curious.

    Thanks again!

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