Mainline - Poly or PVC

Discussion in 'Irrigation' started by Dirt Boy, Apr 11, 2008.

  1. Dirt Boy

    Dirt Boy LawnSite Senior Member
    Messages: 496

    For you guys that do poly:

    If you have more than one valve box, do you run poly for the mainline, or do you use PVC between them?
    I've always had a central manifold, close to POC, my thinking is PVC only, but not 100% sure.
    2' frost is normal here.
    Would you put low pressure drains in, or inform HO of need to blowout at end of season?

    Thanks in advance
  2. hoskm01

    hoskm01 LawnSite Fanatic
    Messages: 5,690

    PVC to the last MANIFOLD, god bless you. If you have the capability on site to do a low drain and would be satisfied that you could sufficiently drain that main, then go for it.
  3. CAPT Stream Rotar

    CAPT Stream Rotar LawnSite Fanatic
    Messages: 6,209

    Up here in New England we use poly all the way..

    works fine..

  4. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,874

    Constant pressure will rule out the utility grades of poly, though. Miles of utility-grade zone pipes are no trouble, but for constant pressure, it's NSF only, and bump up the pressure rating, if need be, since poly pressure ratings are a lot lower than PVC.
  5. Dirt Boy

    Dirt Boy LawnSite Senior Member
    Messages: 496

    Thanks, we never have more than 50 psi available here, and I can easily use NSF rated poly. I guess there's some tradeoffs, PVC has higher pressure rating, but poly has more forgiveness in freezing weather.

    One more detail on this job which relates to this question. The guy wants to possibly add on to his building in the future, so from the POC to the first valve box, it will be a good 20' from existing building to allow for this.

    I will come out of the building with PVC (common around here) or brass to underground, I can then either use PVC to first box, or switch to poly. What have you done in these instances?

    Thanks again!
  6. AI Inc

    AI Inc LawnSite Fanatic
    Messages: 27,090

    50 psi, Leave the PVC at the supply house where it belongs.

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