Watts Anti Siphon Placement

Discussion in 'Irrigation' started by reb12, Jul 7, 2007.

  1. reb12

    reb12 LawnSite Member
    Male, from Florida
    Posts: 93

    OK Gurus, I work in SW FL and one of my clients in a new home has so much sand in his main water line that his sink facets and showers barely flow, and spit out sand. He called a plumber and the plumber is blaming the location of the irrigation backflow device saying it should be installed between the meter at the street, and the copper dual back flow preventer that is positioned about 18" above ground down by the meter. He said since the irrigation line can backflow to the dual copper back flow, it is likely delivering sand to the main line, and getting into the home. I say that's impossible as the irrigation line has a back flow device on it, and it really should be installed up by the above ground valves, about 12" higher than them. Down here, the majority of the irrigation systems have a ball valve with the anti siphon installed down by the meter just in from the street. Does it make any difference what side of the dual copper shut off the irrigation shut off is installed?? Thanks,
    Rick (aka sprayhead)
     
  2. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,794

    I think the plumber is clueless, but just out of curosity, what is the property slope?

    Also, There may be a bad clog introduced by the installation of the backflow preventer from sloppy technique that has proceeded to clog all of the traps on the sinks.

    Just a thought.
     
  3. reb12

    reb12 LawnSite Member
    Male, from Florida
    Posts: 93

    The slope is probably 6-8'. Not great and a small lot. The plumber told him I had to re-hook the main for the irrigation line between the dual back flow preventer and the meter. Does not sound right to me as the Watts anti siphon should not have any back flow devices between it and downstream. Right???
     
  4. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,017

    Got any photos? Watts does not manufacture antisiphon valves per se, as does Irritrol and Rainbird and Hunter.
     
  5. reb12

    reb12 LawnSite Member
    Male, from Florida
    Posts: 93

    No photos. I guess my main qestion is "does it make any difference if the anti siphon on the irrigation main, just above the ball valve, down by the street is connected to the main water line before, or after the dual copper anti siphon on the main line going to the house". In other words you have the meter, then the dual copper anti siphon / shut off valves, then the irrigation hook up after that, or (like the plumber is saying) it should be downstream, but before the dual copper valves. I don't see where it make a hill of difference, as long as I have the required anti siphon right near the start of where the irrigation main line hooks into the main line.

    Sprayhead
     
  6. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,794

    Use MSPaint to make a diagram.

    I'm pretty sure your referring to a Watts Pressure vacuum Breaker, not antisyphon valve.

    I.E.:

    [​IMG]
     
  7. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,017

    My favorite PVB - and a bargain at a hundred-and-a-half. :)
     
  8. reb12

    reb12 LawnSite Member
    Male, from Florida
    Posts: 93

    Here's the pic of the anti siphon that is used almost exclusively down here. The valve manifold is at my home, which is a little older than the one I concerned with, but it is at least a good 12" above the highest sprinkler head. In his case, the shut off and valve is down by the street, by his meter, but installed after the main water line anti siphon dual valve.

    Sprayhead

    Cnv0956.jpg

    Cnv0954.jpg

    Cnv0955.jpg
     
  9. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,017

    That isn't code. It never was. The PVB is the proper device for that application
     
  10. reb12

    reb12 LawnSite Member
    Male, from Florida
    Posts: 93

    I have a PVB down by the street and so does the account I'm talking about. Where I live they also require an atmospheric pressure relief valve mounted just above the irrigation shut off valve. Back to my original question, the plumber is saying that the atmospheric pressure relief and ball valve at the beginning of the main irrigation line should be hooked up between the meter and the PVB, not after the PVB. I say it makes no difference.
     

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