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Testing Back Flow Preventers

chapchap70 Member Posts: 139
I have an Apollo 40-400 series dual check back flow preventer that I will install to prevent boiler water from going back into the building water piping.  There is a procedure in the instructions to test this.  How often do you guys test this?

The one I have is directly connected to a fast fill pressure reducing valve. I do not believe the valves came together from the factory.  There is supposed to be two test cocks with a shutoff valve between them ahead of the back flow preventer.  Then there is a third test cock and another valve.  I don't see how the back flow preventer can be tested (with it directly connected to the fastfill).



  • Al Letellier_21
    Al Letellier_21 Member Posts: 402
    testing BFPs

    Most jurisdictions/water districts require annual testing of BFPs and here in Maine you have to be a licensed master plumber and be certified for testing. Has been a lot of that kind of schooling here this spring and summer. Have a business partner that went to Hartford this spring....it was a 40 hour class !!!
  • D107
    D107 Member Posts: 1,823

    This may be of interest:

  • chapchap70
    chapchap70 Member Posts: 139
    Maybe It can work as a dual unit

    Around here, most residential boilers do not have back flow preventers.  With the few light commercial units I've come across, I haven't seen test cocks and shutoff valves for testing.  I've never asked how anyone knew that the valve was working like it should. 

    The setup with the back flow preventer I have is like a dual unit valve with the backflow preventer is attached to the prv/fastfill.  The Apollo valves website I looked at showed these as separate items and I did not see them attached on the website.

    I don't think I would need 40 hours of training to figure out how to test it; it seems like a simple procedure.  It does not seem that back flow preventer testing is done on boilers that often.  I'll have to see if I can find a Big Tony video on this.  :)

    As I am thinking of this, I don't see why the PRV cannot be attached.  All that has to be done to test it is to drop the pressure lower than the boiler fill pressure for testing.
  • Al Letellier_21
    Al Letellier_21 Member Posts: 402
    backflow preventers

    You are right and I misinterpreted what you had for a BFP. Around here in Maine

    ALL BOILERS are to be equipped with BFP and they are seldom tested  unless on commercial applications or on the water service itself. BFPs like you mention, we see mostly Watts 911s around here and the only issue I see with them is the #b of installers that done run a drip line to the floor or to a safe drain. Many insurance issues with water damage because someone didn't use up some excess PEX and run the vent to a safe place of disposal.....
  • chapchap70
    chapchap70 Member Posts: 139
    edited July 2011
    Just for code?

    If back flow preventers are installed only for code and people couldn't care less if they work, why install them at all? 

    When I went to the supply house on Saturday, they did not even have testcocks I could put on and in typical fashion, the counter man asked another contractor standing there if they are typically installed.   The guy said I don't need them and I should order them from the manufacturer of the BFP. 

    Although this would not be the best way, I guess if there are shutoff valves on either side of the back flow preventer, the union can be loosened and the boiler side valve opened to see if water continues to leak out.   I don't think there are many back flow preventers with shutoff valves on either side; just one on the street pressure side.
  • Plumdog_2
    Plumdog_2 Member Posts: 873
    Backflow Preventers

    Those devices are a whole nuther can of worms. When I took the training and certifications back in '89 or '90 it was a week-long class followed by a pretty tough exam that included demonstrating knowledge of testing. There really is a boat-load of info taught about backflow, cross-connections, siphons,and other stuff a plumber needs to be aware of. That being said, most jurisdictions allow the simple double-check with a vent like the Watts 9D for boilers. No testing required. A lot of first-timers or DIY guys get told they need a "Backflow Preventer" and they end up getting sold a RPZ type device with test cocks requiring anual testing and record-keeping. Call the inspector and see if you can use a double-check with vent.  
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