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flue pipe ratings?

You don't often see that word used in a sentence, ataboy Ken! Must be all that fresh mountain air.

To answer a very good question posed by Joe.

The 2003 International Mechanical & Fuel Gas Codes refer you right back to the manufacturer Joe. I will "assume" (based on your e-mail) that you work for a supplier, right?

Go right back to them (the manufacturer that is), they should of already given you the information needed to answer this question.

Anywhoot, the 03 IMC states in Section 803.9 Chimney (not flue) connector construction: Chimney connectors for low-heat appliances (we are talking about venting an appliance and not some "other" application right?) shall be of sheet pipe having resistance to corrosion and heat not less than that of galvanized steel specified in Table 803.9(1). Connectors for medium-heat appliances and high-heat appliances shall be of sheet steel not less than the thickness specified in Table 803.9(2)

Which application were you interested in knowing, and what diameter because they vary (4 catagories from 5"-larger than 16"). The catagory of appliance is also needed as well, like Ken said, "be careful and read the whole magilla before proceeding".

Robert O'Connor/NJ


  • Joe Moody
    Joe Moody Member Posts: 22

    Does anyone have ratings for standard flue pipe? I had a contractor call me this morning looking for a submittal for an engineer. I was shocked when my supplier told me they do not have ratings for the flue pipe they sell me. I would think that there would be requirements as to what size gauge and temperatures you can use.

    Any information would be appreciated.
  • Ken_40
    Ken_40 Member Posts: 1,320
    Take a look at

    the applicable code for your state; e.g. BOCA Mechanical Code, IBC, etc.

    In the chimney section(s) the minimum metal gage will be mentioned and described for both the horizontal aspect, "the connector," and the vertical piece as well, "the vent."

    The entire section dealing with venting standards is complicated and wildly involved with combustion air as well - depending on which code has been adopted in your area of work. So, be careful and read the whole magilla before proceeding.
  • Joe Moody
    Joe Moody Member Posts: 22

    Ken & Robert - thanks for the fast response. We are a wholesaler of heating equipment. I called our "sheet metal companny" and they indicated that they do not have a submittal or specification sheet for this type of product. My customer put this on a new oil fired boiler and used 12" single wall pipe. Now one engineer is breaking chops looking for the ratings on this flue pipe. I just found it kind of strange that with all the liability going on in the world the company that manufactures this stuff for most of the New York City Area could sell this type of product with out their own specification to its limitations.
  • Rodney Summers
    Rodney Summers Member Posts: 748
    Joe Moody

    The requirements for chimney connectors are more stringent than those for vent connectors because they are subject to to higher flue-gas temperatures, and corrosive flue gases from solid fuels. Chimney connectors must be constructed of sheet steel conforming to the thickness requirements of Table 803.9(1) for connectors serving low-heat appliances and Table 803.9(2) for connectors serving medium-and high-heat appliances. Connector wall thickness increases as the connector's cross-sectional area increases to maintain structural integrity and rigidity. Sheet metal thicknesses are expressed in fractions of an inch (mm) and in industry standard gage designations. Medium-and high heat appliance connectors are often rectangular; therefore, both areas and round pipe diameters are given in the table.

    You say you found it "kind of strange". I'd call it suspect to me. Its quite possible they don't have the submittal because its not been listed and approved. Time to get a sample of this material and have it tested independently to insure it complies. It sounds like its time to get right to the bottom of this one at once, if I were you!!

    As far as the 12" (0-14 Equivelent Round Diameter in Inches)goes, and the application (oil fired boiler) I'd refer to 2003 International Mechanical Code Table 803.9(2) which says it "should be" a minimum of No. 16 Gage (0.060 Minimum Nominal Thickness)for the area (square inches) 0-154".

    Hope this helps.

    Robert O'Connor/NJ

This discussion has been closed.