Pipe Noise!! Help!!

Discussion in 'Irrigation' started by risk636, Aug 8, 2006.

  1. risk636

    risk636 LawnSite Member
    Posts: 1

    Hello, I just installed a system(July 06). I am having a problem with some pipe noise. A little backround...Live in Missouri, main water line comes in basement wall, the sprinkler system is tapped in before a pressure regulator valve, the sprinkler line then runs up the wall and out of the house to the backflow preventer. The noise happens when the zones or stations are opening, I know this because I programmed a delay in the system between zones and the noise happens only when the valves are opening. I put an air arrestor on to try and stop the problem, but not working. My pressure at the hose spigit is 60-65, wihich is after the pressure regulator in the basement. I noticed when try to clear air form the lines (thought that might the problem) that the nose stops when the bathtub is running which is the first outlet on the water line. The install is no different than 10 other I've intalled this month." The only relief I found was in reducing the pressure via the regulator valve. I am worried because I don't want the pressure in the house to drop to a level that is noticable in the shower. Please help and I will provide any more info. Also there is a Potable Water Expanansion Tank on the cold water line near the hot water heater which is at the other end of the basement. Don't know if this makes snese but the nosie at startup is unbearable for a few seconds then is fine til the next zone kicks on. Could the sprinkler system be robbing the pressure form the house?? Does the PVR allow water to go both ways that the only way any of this makes sense, because when I turn the adjust nut out to reduce pressure the noise is gone. But like I said I don't want the rest of the house to suffer. Thanks KK
     
  2. Flow Control

    Flow Control LawnSite Bronze Member
    Posts: 1,267

    After your tee on the regulator side install a dual check. This will do the trick 95% of the time.
     
  3. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,997

    How much does the house suffer if you reduce the pressure? These valves are set at 45 - 50 psi at the factory, and most household fixtures can do fine with even less.
     
  4. telcomac

    telcomac LawnSite Member
    Posts: 32

    Hello, I just installed a system(July 06). I am having a problem with some pipe noise. A little backround...Live in Missouri, main water line comes in basement wall, the sprinkler system is tapped in before a pressure regulator valve, the sprinkler line then runs up the wall and out of the house to the backflow preventer.

    If I read this correctly, and you are tapped in before the pressure regulator, then any adjustment you make to the regulator will only affect whats after it.
    Just my 2 cents!:waving:
     
  5. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,799

    What size is your line in the basement heading outside?

    Also, did you restrain it in any way?
     
  6. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,997

    It may be that the inflow of water into the system is temporarily creating a lower pressure at the point of connection, than the regulated pressure in the house, so the house water would momentarily try to flow back towards the sprinkler system. A pressure gauge could confirm this. Since reducing the house pressure reduces the noise, that would support this pressure-differential hypothesis.

    A check valve after the PRV might stop the banging, but it would also defeat the internal safeguard that is built into a PRV, that allows excess pressure to slowly bleed back through the valve.

    Unfortunately, there aren't any economical control valves that can handle this situation. With a thosand dollars to spare, you could install a small "process control valve" of the 'pressure sustaining' type, and prevent the surging.
     
  7. Flow Control

    Flow Control LawnSite Bronze Member
    Posts: 1,267

  8. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,997

    I'd be curious to see what the noise would be if there wasn't an expansion tank on the water heater.
     
  9. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    I just went to a house yesterday for pipe noise. It was banging/hammering whenthe last valve (#3) shut off. The PVB would dump water for over a minute and the valves would have a hard time shutting down. The screw in the PRV was adjusted all the way down, but I couldn't check pressure. My guage was broken earlir in the season by a system that was close to psi, and I never replaced it. So I just backed off the adjusting screw, checked to see that the zones were still operating ok, and that helped.

    Due to the high pressure and 16 year old DV valves, the zones still were not shutting down very well. Changed out the diaphragms and all is great. No banging at all.

    Oh wait. Should I have changed out the whole valve??? :rolleyes:
     
  10. Hank Reardon

    Hank Reardon LawnSite Senior Member
    Posts: 599

    I would have changed out the guts of the valve on a sixteen year old system.
     

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