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Water hammer

Discussion in 'Irrigation' started by rainsofthouston, Jul 25, 2012.

  1. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    Never know with you. Who are you today? Jekyll or Hyde? :)
  2. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,976

    I'll know better once we get back on the road.

  3. jbell36

    jbell36 LawnSite Bronze Member
    from KANSAS
    Posts: 1,286

    what exactly does over-zoned mean, too many heads on one zone? i'm trying to figure this kind of situation out too, i ran across this earlier this year...
  4. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 21,976

    Yes, older, smaller water systems will vary in flow/pressure during a 24 hour period, depending on demand. We bought a data logger for a water system that was known to to have crummy psi/gpm performance and found the best time of the night to run the irrigation.
  5. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    Not necessarily too many heads. Too many outgoing gallons per minute.
    You could have 20 heads at 1 GPM each, equaling 20 GPM. Or you could have 20 heads with 4 GPM each, equaling 80 GPM for the zone.
  6. grassman177

    grassman177 LawnSite Fanatic
    Posts: 9,795

    i often find that the system that causes hammer the most, is one that is over stretched as far as gpm on a zone.
  7. mitchgo

    mitchgo LawnSite Silver Member
    Posts: 2,780

    Back to the OP

    It really does depend on where the hammering is happening and at what point the hammering is happening ( Ie At the pressure reducing valve inside the neighbors house when the sprinkler system turns on , or all through outl the house when the system turns off... or constant noise running through the house when the system is running. ect ect)

    Improper designs and high water pressure are the leading causes of hammering . There are many other scenarios

    Check valves on the service line help.. Water hammer arrestors help.. Pressure Tanks help.. Pressure Reducing Valves help... But it really is site specific - All those things installed and the noise could still be happening..

    I've also seen the water meter itself being extremely loud and the noise echo's through the pipe and into the house

    If it's a 10 year old house the meter ' Should ' have a check valve already built into the setter
  8. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    Any time I get called out to "fix" the rattling, hammering, banging, of the pipes, I tell them it is all time and materials, and I guarantee nothing. It may stop while I change or add things, then it may start up again the next day. It can be a combination of things due to poor install, poor design, higher or lower pressure than originally, someone added onto the system and never told me, failing pressure regulator, failing water meter, wrong type of backflow valve, or just plain gremlins in the system.
  9. jbell36

    jbell36 LawnSite Bronze Member
    from KANSAS
    Posts: 1,286

    great way to explain it, makes perfect sense
  10. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    ...... but but .... a 5/8 meter can flow 20 GPM no problem .... according to boots. :laugh:

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