troubleshooting pressure/flow issues

Discussion in 'Irrigation' started by Bill S, Jul 7, 2007.

  1. Bill S

    Bill S LawnSite Member
    Messages: 184

    Ok, here's the situation...

    70# pressure coming out of the house, I have not done a flow test though I will Monday morning.

    New back flow device installed. The zones aren't getting enough pressure to lift any of the heads. On each zone a head will rise about 1/2 way and a slight stream of water will shoot 5' or so....

    This system worked (from my knowledge) fine last spring. There is no leaks before the valve (water meter doesn't spin at all when clock is in standby position).

    Any ideas? :hammerhead:

  2. irritation

    irritation LawnSite Gold Member
    Messages: 3,582

    Could be a bad meter restricting the flow or a valve that is only partially open. I had one like that and a curb **** was not open all the way.
  3. londonrain

    londonrain LawnSite Silver Member
    Messages: 2,129

    What valves are on the system?
    Is there a master valve on the system?
  4. Bill S

    Bill S LawnSite Member
    Messages: 184

    rainbird valves, no master valve...70 pounds of pressure right before back flow, unknown pressure after back flow.
  5. londonrain

    londonrain LawnSite Silver Member
    Messages: 2,129

    If you have dv-100's not opening completely is not a common problem but not opening at all is. I have seen the rubber washers used in water meters swell and restrict the flow and the pressure was just fine. I would check your water flow from the meter..
  6. Bill S

    Bill S LawnSite Member
    Messages: 184

    OK, maybe we are getting somewhere....Just got info from their plumber that he installed a filtering system right after the meter! A clogged filter will greatly reduce flow, thus reduce irrigation system capabilities, no?
  7. Dirty Water

    Dirty Water LawnSite Fanatic
    Messages: 6,794

    Yes, move your irrigation tap before the filter. There is no reason to ruin house water filters by moving irrigation GPM through them.
  8. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,400

    Even unclogged, a house filter can kill lawn sprinkler performance.
  9. PurpHaze

    PurpHaze LawnSite Fanatic
    Messages: 5,496

    ... and in addition to the filter, not all backflow devices are equal in regards to their pressure loss ratings.
  10. Bill S

    Bill S LawnSite Member
    Messages: 184

    replaced all the nozzles, cut the size in half...system is working well now!

    Advised client to move the filter to after the irrigation system.

    Thanks for your thoughts and advice

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