Thermal Cover for PVB

Discussion in 'Irrigation' started by BodegaBay, Apr 26, 2007.

  1. BodegaBay

    BodegaBay LawnSite Member
    from NV
    Posts: 3

    Many years ago a lawn irrigation specialist recommended I use thermal cover in addition to winterizing my PVB (24" above ground). I think the name of the product was "Polar" something. It worked for many years in my old house -- never had a PVB froze yet.

    However, in my new house I installed a new PVB last year and it just cracked yesterday over a two week period where the weather got frozen again.

    I have two questions:

    1. Anyone know the thermal cover I'm speaking of? It's green and looks like a pillow but open on one end so you can slip it over a PVB assy.

    2. What's high quality PVB (3/4" opening). Thanks.
     
  2. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    Here's one: http://protecoversusa.com/ You can do a web search for "backflow blanket" and others show up.

    Watts, FEBCO, Wilkens all have them.
     
  3. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,017

    Watts does offer a line of PVBs with an internal bypass, that's designed to blow a bit of water when the device begins to freeze.
     
  4. BodegaBay

    BodegaBay LawnSite Member
    from NV
    Posts: 3

    Thank you guys.

    BTW, the unit that I bought last year was a Watts with that internal bypass. I guess I didn't drain it fully and that little water might have caused the crack. Don't know if Watts' warranty will cover this...
     
  5. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,017

    Warranty coverage for leaving water in a backflow preventer over the winter? Oh, ha-ha, it is to laugh.
     
  6. BodegaBay

    BodegaBay LawnSite Member
    from NV
    Posts: 3

    Ok, ok... I thought I'd give it a shot with the distributor. If I can sweet tallk them into it, I'll be the one laughing!
     
  7. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,017

    Hey, no harm in trying. Do understand that the 'freeze protection' depends on the water still being turned on, so that a flow through the bypass can prevent the thing from freezing completely solid.
     

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