2 zones popping on.

Discussion in 'Professional Discussions' started by greenmonster304, Aug 12, 2019.

  1. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 52,591

    Until the main line is pressurized and the internal pressures equalized within the zone valves, they are free to do whatever. Some systems are on the edge of total failure by way of multiple zone valves staying open when a pump is first turned on.
     
    zr100 likes this.
  2. ArTurf

    ArTurf LawnSite Fanatic
    Male, from Ark
    Messages: 6,310

    yes I've experienced this. Until I replaced several Pro Flows couldn't get any zone to work since most of them were effectively running aka open
     
  3. DitchDiggler

    DitchDiggler LawnSite Member
    Messages: 20

    Sounds like a hydraulics and design issue. The pressure on the top of the diaphragm is dropped too quickly, allowing the valve to open. As the pressure builds back up it closes, just as boots said. Try adjusting the flow control on the valves or nozzle down the heads. Or install a VFD.
     
  4. OP
    OP
    greenmonster304

    greenmonster304 LawnSite Platinum Member
    Messages: 4,174

    Well Friday as an experiment I hooked up a pressure tank near the well head and it seems to have cured the problem.
     
  5. 1idejim

    1idejim LawnSite Fanatic
    Messages: 12,654

    Water hammer :)
     
    Outlawn and greenmonster304 like this.
  6. Outlawn

    Outlawn LawnSite Bronze Member
    Messages: 1,203

    2432BC2C-55BB-4245-BCCA-53BC37815316.gif
     
  7. Outlawn

    Outlawn LawnSite Bronze Member
    Messages: 1,203

    It could have something to do with the air being in the lines. I’ve notice that if I have to do a mainline repair, quite often one or more zones will pop up for a few seconds and then go back down.
     
  8. Garrett1234

    Garrett1234 LawnSite Senior Member
    Messages: 673

    Just a question about this issue for my education:
    If a zone has a dedicated valve, wouldn’t that zone turning on when not “told to do so” mean it’s a bad valve?
    Or is there a failsafe in valves that cause them to open upon pressure exceeding their stated capacity?
    In regards to a vfd, there’s a cycle up time which can be adjusted so the pump won’t just hit full hyper speed trying to maintain the psi.
    Was the conclusion of this issue determined the ramp up time on this pump was so short and the pump so strong it blew open valves?
     
  9. OP
    OP
    greenmonster304

    greenmonster304 LawnSite Platinum Member
    Messages: 4,174

    The system and pump was in place when I came on the seen. It was for dust suppression on a dressage ring. We expanded it to irrigate the jumping field. If I was starting from scratch I probably would have done something different with the pump. It is a $$$ 7.5 hp submersible $$$ so I don’t think they will replace it with a VFD if it can be fixed with a $500 pressure tank.
     
    1idejim likes this.

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