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Has Anyone Ever Seen

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CMadatMe
CMadatMe Member Posts: 3,086
Any testing data for PVC Sch 40 as it applies to flue gas venting? I read in all the install manuals on boilers that states PVC that meets ASTM D1785 is ok to vent with. Here is a note direct from the standard.



"This standard specifies dimensional, performance and test requirements for plumbing and fluid handling applications, but does not address venting of combustion gases."



My question is to the boiler and furnace mfgs and we all know they lurk. I do not expect them to reply here but an e-mail would be nice. What testing data do you have that says a pipe that has not been tested for venting but meets the above standard is ok for venting? Why do you list a standard that has nothing to do with using PVC as a means of exhuasting flue gases in your manuals? The common person nor the trade contractor know the standard. It seems to me that that the use of the standard in the manuals is used as giving one a sense of comfort that as long as it meets this standard it's ok to vent with and that is just not the case. Manufactures should have to at a minimum have a note right next to that standard that states the above.



Now I'm done venting.

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  • Tim McElwain
    Tim McElwain Member Posts: 4,628
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    Chris I wrote

    two articles a while back in the HVAC Insider about this very subject and my research found no evidence that any testing had ever been done by anyone on PVC and CPVC for use as a venting material.



    I did however get a very interesting letter from the president of Viessmann agreeing with what I called my theory about residual gases (chloride) getting back into the combustion chamber after shut down. I also referred to high temps possible with domestic hot water. He stated in his letter that my theories were not theory but facts as proved by some testing done in Europe.
  • CMadatMe
    CMadatMe Member Posts: 3,086
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    I can't find any either

    I'm searching high and low Tim and have come up empty. I guess the issue that   bothers me most is the listing of the ASTM Standard in the manuals. It shouts that PVC is ok to vent with because it meets it. This is clearly a misrepesentation of the standard. If they are going to list the standard they should have to list that the standard does not test for the use of PVC for the removal of combustion gases. 

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  • Tim McElwain
    Tim McElwain Member Posts: 4,628
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    I haver been shouting

    about this for over 10 years but it seems to fall on deaf ears.



    I have instances on real old PVC and CPVC hookups of deteriorating of the fittings and in some cases softening of the pipe itself that along with sagging issues even when supported.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
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    Good luck in your search Chris....

    Let us know if anyone fesses up :-)



    ME

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  • Leo_G
    Leo_G Member Posts: 89
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    System 636

    is the ONLY pvc/cpvc piping that is CSA approved for venting. Been required in Canada for the last three or soo years. Yes, even Viessmann allows it on their boilers.



    In B.C., the gas safety branch has made 636 CPVC mandatory for ALL boiler installs, even if they are not supplying high heat. 



    So far we only have Ipex as a supplier, and the cost is out of this world. Hopefully other pipe manufactures will jump into the fray soon, and hopefully drive the price down somewhat!
  • CMadatMe
    CMadatMe Member Posts: 3,086
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    There Is

    Leo look at this www.centrotherm.us.com . It's ULC-S636 and 1/2" the price. I'm meeting with them today.



    Mark  you know nobody will fess but I'm going to keep on reasearching.

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