Irrigation Backflow preventer water hammer?

Discussion in 'General Plumbing Help' started by marlonc497, Jul 19, 2019.

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  1. Jul 19, 2019 #1

    marlonc497

    marlonc497

    marlonc497

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    Hi guys, quite puzzeled right now. Today woke up early in the morning to a terrible constant pipe banging sounds coming from the pipe leading to the irrigation valves. The sound was quite audible from outside where the backflow preventer is. The backflow preventer was leaking a lot water from the top. This was all happening while the sprinkler system was running. I had to close the valve feeding the system from inside the home to stop the banging. What could be the cause of this? The backflow preventer seems to be quite similar to this https://i.ebayimg.com/images/g/QZEAAMXQU6tQ~gRM/s-l300.jpg

    Thanks!
     
  2. Jul 20, 2019 #2

    Geofd

    Geofd

    Geofd

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    what you need is a spring loaded check valve no more than a foot in front of the back flow any time I install a backflow device I do this it stops the valve from chattering the zone valves are electric and open very quickly
     
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  3. Jul 21, 2019 #3

    marlonc497

    marlonc497

    marlonc497

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    Thanks for the reply! So I would put spring loaded check valve between the backflow preventer and the zone valves. Also would a sharkbite inline check valve work? Thanks again for the reply!
     
  4. Jul 21, 2019 #4

    Geofd

    Geofd

    Geofd

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    no...I goes in front of the back flow device the rush of water and the loss of pressure from the zone valves opening affects it...also you could put a hammer aresstor after the backflow that would also help
     
  5. Jul 21, 2019 #5

    marlonc497

    marlonc497

    marlonc497

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    Oh my bad I see now. Thanks'
     

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