Blow-Out Question

Discussion in 'Irrigation / Sprinkler Forum' started by eddy, Nov 7, 2009.

  1. eddy

    eddy New Member

    Messages:
    4
    Location:
    Front Range, Colorado
    Hey folks,

    Just found this forum and it looks like a tremendous resource. I enjoy tinkering with my sprinkler system as I have a old fixer-upper and the landscaping and irrigation are a large part of the projects.

    I'm trying to blow out my irrigation system, and I have a Febco 710-1 atmospheric backflow preventer. I'm able to shut off the supply line and then open the drain to the standing line. But I can't figure out how to connect the compressor to the system. Most of what I've read refers to connecting to a downstream blowout fitting, but I can't seem to find such a convenient sounding bugger!:confused:

    Any suggestions, I'd be most apprecative!

    Here's a pic:

    [​IMG]
  2. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    Your PVB doesn't have test cocks. It would not pass code in most parts of the country. It also appears to be to low, it should be 12" above your highest head.

    John
  3. eddy

    eddy New Member

    Messages:
    4
    Location:
    Front Range, Colorado
    Thanks John. I noticed mine looked different than all the other examples I've seeing...

    I'm in an unincorporated part of the county here, so I don't know about the water code.

    In any case, if unscrew the bonnet portion of the AVB and rig a fitting that will fit that to the compressor, would that work to blow out the lines?
  4. BRD

    BRD New Member

    Messages:
    53
    Location:
    northeast
    What you have there is a atmospheric vacuum breaker (avb) not a pressure vacuum breaker (pvb). AVB's do not have test ports. Try looking in one of those green valve boxes, maybe there is a boiler drain where you can connect up to blow it out. If it is a old system and it has been winterized before then there has to be a connection to hook up to somewhere.. Check at the system shutoff valve area for a blowout. By the way, AVB's are not designed to be under constant pressure for indefinite periods. It looks to me from the pic like that is the case here. A appropriate backflow device would be a PVB.
  5. eddy

    eddy New Member

    Messages:
    4
    Location:
    Front Range, Colorado
    Thanks BRD. I will check it out. I had someone blow it out for me last year, and I could have sworn he connected directly to that AVB, but that was a long time ago, I could be mistaken. I will dig around in those valve boxes....and worse case, I will hire a landscaping company and take better notes this time!
  6. tomm

    tomm New Member

    Messages:
    41
    PVB is the minimum device required in Colorado for a residential sprinkler system, although its not enforced in every locale.

    Ideally you should replace with a PVB and add a blowout/drain connection after it. You may already have a drain in your valve box that can serve as the blowout connection, but they are generally a PIA to deal with.

    What are of Colorado are you in?
  7. eddy

    eddy New Member

    Messages:
    4
    Location:
    Front Range, Colorado
    Thanks, Tom.

    I'm in Boulder County - east of the town of Boulder. I am not at all opposed to replacing the breaker and installing something that would not only meet code but also be more serviceable.

    Would I cut out the breaker and solder in the new pieces? Or....maybe I should do some more research to be able to discuss this intelligently.

    Cheers,

    Eddy
  8. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,384
    Location:
    Yakima WA
    EPA regulations are Federal, but seem to be left to the states to enforce and the state usually turns it over to the locals. Result of that is there is a serious gap in what is enforced. You really should have an approved backflow device to prevent cross contamination of not only your water, but the water of everyone on your water supply system. This device should be re-certified each year by a licensed technician. My city enforces this to the letter, but I know many places do not. Cost for inspection and re-certification runs $35 to $50. It might be a good idea to hire a professional yard service to not only blow your lines this year, but inspect what you have and advise you on what you should have. Next spring you can install a proper devise with blow out provisions.
Similar Threads: Blow-Out Question
Forum Title Date
Irrigation / Sprinkler Forum Questions about Pressure Vacuum Breaker Aug 7, 2014
Irrigation / Sprinkler Forum Hunter Icc Controller Question Jul 26, 2014
Irrigation / Sprinkler Forum Sandpoint question Jul 12, 2014
Irrigation / Sprinkler Forum Solenoid Manual Control question Jun 8, 2014
Irrigation / Sprinkler Forum RPZ Backflow installations question Sep 2, 2013

Share This Page