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High pressure concern.

Discussion in 'Irrigation' started by PerfiCut L&L, Jul 11, 2010.

  1. PerfiCut L&L

    PerfiCut L&L LawnSite Senior Member
    Posts: 458

    We're new at irrigations and have installed a few small systems without any problems. Used some assistence from the local supplier on the first install but after that, the others we did were prety strait forward.

    I have an opportunity to pick up a few larger properties 1 acre + and have a few questions.

    The pressure on the system is 120-124 psi, and the meter is inside the house. My first questions is for those in the DC area. Apparently WSSC offers a submeter, for irrigation use. Can anyone recommend an installer?

    My second question is, since the customer has a lot of pressure should I plan to install some type of water pressure regulator? There is a long supply run of about 250'-300' to get to a section of the property that is 120'x50'.

    All of our other jobs to date have been on properties 1/4 acre or less with 75-85 psi pressures, and we have used 3/4 pvc for supply lines. We plan on using 1" lines with project unless we should go larger. I will be talking with the local rep this weekend for some additional guidance.

    Thanks in advance for your help.
  2. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,643

    Either you employ a brass pressure reducer in the system supply (like a Wilkins BR4) or you employ a master valve with a pressure-regulator built in.
  3. mitchgo

    mitchgo LawnSite Silver Member
    Posts: 2,780

    ditto on that
  4. adamills

    adamills LawnSite Member
    Posts: 5

    having 120 psi through a 5/8 meter will only give you around sixty psi through 1 inch poly or around 54 psi through 1 inch pvc depending on what you use. because of how city water works no matter what you are going to be fine if the meter is 5/8 or 3/4 inch. always safe to open a hose spicket and see if you can even fill a five gallon bucket in 15 seconds that is 20 gpm at around fifty psi "almost perfect"
  5. mitchgo

    mitchgo LawnSite Silver Member
    Posts: 2,780

    Wow man..... You really need to learn basic hydraulics and follow your flow charts

    everything you just said is a complete lie
  6. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,643

    As a practical matter, 120 psi is about where I begin to worry a bit about zone valves rated for 150 psi working pressure. If a Wilkins BR4 is set for 100 psi, that should leave enough pressure downstream for good performance, while providing overpressure protection for poly pipe mainlines.
  7. PerfiCut L&L

    PerfiCut L&L LawnSite Senior Member
    Posts: 458

    the hose bib only gave me about 10-11 gpm. It took 27 seconds to fill a five gallon bucket. But the supply feed for the bib is only 1/2" line.
  8. GreenLight

    GreenLight LawnSite Senior Member
    Posts: 466

    One thing to be very wary of (at least here) is many spickets that come off the house are not coming directly from the 3/4 or 1 inch supply line. In many cases (especially in the back of the home) spickets are coming from the indoor plumbing which has already been downsized to 1/2 inch and in many cases it has been regulated by a bell regulator in the indoor plumbing. It is not terribly uncommon for the spickets to all be regulated as part of the indoor plumbing before exiting the home.
    Last edited: Jul 11, 2010
  9. PerfiCut L&L

    PerfiCut L&L LawnSite Senior Member
    Posts: 458

    The supply line for the hose bib has been downsized and I am not sure if it is after the house PRV or not. (I dont recall).
  10. ARGOS

    ARGOS LawnSite Silver Member
    Posts: 2,808

    Where's Mike? He could straighten this out in two words or less.

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