Okay to blow out sprinklers through Backflow?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by David Sev, Sep 6, 2020.

  1. David Sev

    David Sev New Member

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    Location:
    Lakewood, CO
    I just had a sprinkler system installed in My backyard and after researching it looks like my only option to blow out my lines is to blow through the test cocks on the side but have read you aren’t supposed to blow through Backflow preventer. Is it okay to blow through one of the side ports before the Backflow preventer?
     

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  2. WorthFlorida

    WorthFlorida The wife is still training me.

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    Orlando, Florida
    You have a Pressure Vacuum Breaker Backflow Preventer. Is this picture turned 90 degrees? The round bell looking cap must be on top.

    Do not blow air into any test port on the device. Here is Febco's procedure for drainage and freeze protect. You do need air but the connection needs to be past the preventer. On the diagram it would be a location "E" and there should be a drain before the device and after the shut off.
    http://www.backflowpreventer.com/media/cms/Febco_765_Freeze_Protection_Manual.pdf

    http://www.backflowpreventer.com/media/cms/Febco_765_Maintenance_Manual.pdf

    Screen Shot 2020-09-06 at 11.45.18 PM.jpg
     
    Last edited: Sep 13, 2020
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  4. David Sev

    David Sev New Member

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    Thanks for the reply. I guess that is my Problem in that I don’t have any connections after the Backflow preventer except for the water drain in my control box. Wondering if I need to have one installed.
     
  5. David Sev

    David Sev New Member

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    And yes the picture uploaded at 90 degrees
     
  6. Sylvan

    Sylvan Still learning

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    New York
  7. ktornquist

    ktornquist New Member

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    Location:
    Colorado
    Going to piggy back off of this thread. I posted in the irrigation forum, but haven't received any feedback. Hoping you all can help me in here.

    I have done some YouTube and forum research, but cannot find anything specific to my situation so I wanted to get your input here. We have a small, single zone drip line system for our back yard flower beds. Over the last several years, I would just pay the company that installed it to come out and winterize it. I watched them do it last time, and to my failure, I did not note all of the steps. Specifically to the step of hooking the compressor up to the PVB. I have seen conflicting information online about blowing out the system through the PVD; however, this is how the sprinkler company has done it and that is the only connection point within the closed system.

    Here are the steps I am planning to follow for the winterizing:
    1) Turn off water supply in basement. This line is tapped into the cold water supply line upstream of the hot water heater. *Yes, I know the picture shows the supply valve already off. We had a quick two days of snow here and dropping temps so I shut off the supply, ran a quick 2 min cycle to purge lines and then shut-off controller.*

    Sprinkler_1.jpg

    2) Open the testcock valves outside at the PVB and then unscrew the small brass cap just upstream of the supply valve to drain the line upstream of the PVB.

    Sprinkler_2.jpg
    Sprinkler_3.jpg

    3) Connect the air compressor to the testcock, turn on compressor to 50 psi and run few mins on the cycle from the controller.
    *Which testcock should I connect to?*
    *Do you know what attachment to the compressor hose will work?*


    4) leave testcocks and valves at PVB to half open.

    Looking for input on steps and help with questions listed. Thanks in advanced!
     
  8. Sylvan

    Sylvan Still learning

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    It appears someone may have used a self cleaning flux which is proven to give a premature life span to copper tubing

    [​IMG]
     
  9. WorthFlorida

    WorthFlorida The wife is still training me.

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    Sorry I have not been this forum for a few days.

    Read above as how to blow out your system as described by FEBCO. I have some recommendation from your picture. IF you do not know how to sweat pipes, then use Sharkbite fittings. They work great, and very easy to use. Do use a pipe cutter on the copper for burr free cuts.

    In the inside of the home, close the valve and open the remove the drain cap. This will allow water to drain from the FEDCO to this valve. When it is complete, close the valve just below the FVB before using air.

    FEBCO.jpg
     
  10. ktornquist

    ktornquist New Member

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    I was wondering about that. The previous owners had this drip installed prior to us. But it seemed odd.
     
  11. ktornquist

    ktornquist New Member

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    Apr 27, 2020
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    Thanks for the info. The last three years we’ve had the company that installed this drip line come out to winterize. They always used the testcocks, but it sounds like that isn’t right. Sharkbites meet code and hold up in weather? I’ve sweat copper before but would prefer to go easy route.

    What air fitting would you suggest installing there? I saw higher up in the thread another poster suggestion a hose bib?
     
  12. ktornquist

    ktornquist New Member

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    Apr 27, 2020
    Location:
    Colorado
    Looking at a tee like this to use at the first joint and then a small stub to the left for an air fitting. Still unsure what air fitting to use when looking at the sharkbite site.

    https://www.sharkbite.com/products/brass-push-tee-0

    Hope I can get enough slope on pipe. Have to go either over or below the supply line coming out of house.
     
  13. ktornquist

    ktornquist New Member

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  14. WorthFlorida

    WorthFlorida The wife is still training me.

    Joined:
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    Occupation:
    Retired
    Location:
    Orlando, Florida
    it doesn’t have to be an air fitting. A ball valve would be good and anyway to fashion a hose from a compressor will do. Depending on how long the drip
    line is it may self drain with just the valve open. At the lowest level of the drip line you can fashion a valve and let gravity do the work. It’s important to drain the FVB. The horizontal pipe needs to be at least level, a very slight pitch would be beneficial but not required.
     
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