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flexible ss chimney liner sizing chart

TonyS Member Posts: 849
does anyone have a link to a liner sizing chart? Thanks


  • TonyS
    TonyS Member Posts: 849
    Thank you Mark

    One more question. I have an existing boiler, cast iron natural draft. It is 210,000 in and comes with a 7 inch vent hood. According to the chart, 2 foot horizontal and 35 feet vertical I should be able to vent this boiler with a 6 inch liner(a 7 wont fit). Is that permissible to reduce the smoke pipe after the vent hood?
  • Henry
    Henry Member Posts: 998
    Reducing the vent connector size

    " if the size is reduced, the change shall be made at the aplpliance flue collar"
  • Tim McElwain
    Tim McElwain Member Posts: 4,625
    The six inch

    liner should be able to handle your BTU load as long as no other equipment is connected. Typically liners have about a 20% less capacity than double wall pipe but it will still be okay. Using a type "B" double wall connector instead of single wall will also help.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    I believe so...

    I know not what code you're operating under Tony, but under the UMC, if it can be proven that the chimney can carry the load, as in your case, AND it is serving a single appliance, you can reduce the chimney liner by one pipe size from the appliances connector, and as Hank pointed out, it MUST be done at the appliance connector,and should be a tapered reducing connector.


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