Water hammer help, please!

Discussion in 'Irrigation' started by jcom, May 25, 2006.

  1. jcom

    jcom LawnSite Senior Member
    Posts: 791

    We always zone for 11-13 gpm on a one inch line with one inch meter, backflow, and 1" valves. Customers are experiencing some water hammer. I thought by allowing the low flow rates that water hammer would not be an issue. Please advise "irrigation gurus" as I am at a loss for the solution.

    John:hammerhead: :hammerhead:
     
  2. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,019

    What pressures? What valves? Some can hammer more than others.
     
  3. Flow Control

    Flow Control LawnSite Bronze Member
    Posts: 1,267

    the pipes are making noise when the zones are shutting down are starting up?
     
  4. jcom

    jcom LawnSite Senior Member
    Posts: 791

    We are using Hunter PGV valves and pressures of 60- 70 psi. One customer is experiencing a lot of pipe noise when the system is running. Another on valve opening.

    Thanks for the help,

    John
     
  5. Water valve to meter not on all the way?
    House main valve not on all the way?
    Pressure regulator set low?
    Pressure regulator failing?
    Thin walls? ;)
     
  6. Flow Control

    Flow Control LawnSite Bronze Member
    Posts: 1,267

    I am not sure if the water meters are in a pit of the house where you are at. But if they are in the house you may want to check to see if the meter is the problem by removing it and just place a peace of threaded pipe in its place to see if the system is making the same noise without the meter. We have found that if there is noisey pipes when a zone is starting up then a dual check on the house line after your tee will 95% of the time solve this problem. With other less effective solutions being shock arrestors and pressure tanks. Just my two cents.
     
  7. jcom

    jcom LawnSite Senior Member
    Posts: 791

    Thanks for the info. I suspect the meter shutoff or the meter itself where the owners' pipe are really vibrating while running.

    We will wait and see on the other. Our Hunter valves are soft closing so just don't see the problem on our end.

    John:cry:
     
  8. Flow Control

    Flow Control LawnSite Bronze Member
    Posts: 1,267

  9. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    Modern automatic valves are slow closing for this very reason. Nothing like slamming a water supply shut quickly to get the juices flowing.:)
     

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