What kind of backflow do you all use?

Discussion in 'Irrigation' started by JimLewis, Jun 19, 2003.

  1. JimLewis

    JimLewis LawnSite Fanatic
    Posts: 6,842

    In these parts Double Check Valves are pretty much the standard backflow device on 99% of the residential irrigation systems that have been installed by a contractor. There are specific reasons why Double Checks are preferred in our area. And if someone really wants to know - just ask.

    Otherwise, I was just curious what the rest of you all used.

    For those in warmer climates, I assume you use some sort of above-ground backflow device like a AVB, PVB, or AS Valves. But those seem so tacky - to have these big things sticking up in the air along side someone's house.

    And for those in the cooler climates where it freezes deep (e.g. Colorado, Dakotas, Montana, etc.) I would think you'd use a double-check as well because of the fact that it's underground and at least somewhat protected from the freezing.
     
  2. therainman

    therainman LawnSite Member
    from IL
    Posts: 196

    We use most rp's. We do however cover a lot of them with a GOOD fake rock same with a booster pump if needed.


    shawn
     
  3. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    For some reason double checks aren't accepted by regional building code here in COlorado Springs for irrigation. Some homes have them inside but a seperate RP or PVB is necessary outside.
     
  4. We us PVB's...as far as them being tacky.....whatever. Maybe they are, they are the preferred valve in Arizona. But, how can you say a PVB is tacky when it is sticking up alongside a house that has another house on either side of it that has the same PVB? Back in the 70s and 80s, people installed their PVB's right next to the water meter in the middle of the front yard!!! Those are my favorite....then when the plumber comes in and replaces the galvanized service with copper.......ooops they forget to hook up the PVB again! Great huh?
     
  5. rvsuper

    rvsuper Senior Member
    Posts: 930

    Watt's 800M4 FR

    lawnspk 003.jpg
     
  6. HBFOXJr

    HBFOXJr LawnSite Bronze Member
    Posts: 1,712

    We use Watts 800 M4 FR.

    Hey RV, where the blow out???????????

    Double checks DO NOT MEET the national plumbing code for irrigation. Irrigation systems are "high hazard" devices. The only acceptable devices are PVB's, RP's and AVB zone valves. The fact that your code enforcement people don't know better doesn't lessen your risk of exposure should contamination occur.
     
  7. rvsuper

    rvsuper Senior Member
    Posts: 930

    Harold,
    It's in the inside of the house. I use a boiler drain right after the main shutoff, this way I can blow everything out at the same time. I know some people say not to blow out through the PVB, but my supplier says it's fine, and I have never had any problems doing so.

    dsc 002.jpg
     
  8. HBFOXJr

    HBFOXJr LawnSite Bronze Member
    Posts: 1,712

    I hate dragging hose inside to winterize a system. So here is how we do it.

    Several other tips.

    1. Use a pvc male adapter into a copper female adapter. The unreinforced female pvc adapter can be overtightened and split and make a mess.

    2. Better yet, can the pvc ball valve and switch to brass ball valve. The Brass ball valve can be threaded onto a copper male adapter then switch to pvc if you must. The PVC ball valves invariable fail leaking water over the winter into the pvb and freezing it. If you leave the boiler drain open you have drippage in the basement.

    3. With the set up like you see here which is also the common way it is done here, it is easy to drain quickly if there is a sudden freeze and super easy to blow out.

    good pvb low res.jpg
     
  9. greenworldh20

    greenworldh20 LawnSite Senior Member
    Posts: 659

    harold,

    install a 'heel t' instead of a coper 't' when the water service line exits the house. then install a female threaded boiler drain. it will be easier to winterize.

    second, why are you guys running pvc inside a residential account. that is against code in ny.

    brian
     
  10. rvsuper

    rvsuper Senior Member
    Posts: 930

    Nope not here, there is very "unstrict" code here for irrigation, but usually I go to how I've seen other systems installed in other cities. Heck, code here doesn't even require a backflow device!
     

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