Irc/ifgc 503.4.1

[Gregg Harris]

Plastic piping used for venting appliances listed for venting materials shall be approved.

Question is how many jurisdictions will not approve of PVC Foam Core Pipe for venting 90 plus furnaces?

"not boilers"

And if not why?

 

[steveray]

I think the manufacturers don't allow it...but I have not come across it....

 

[Daddy-0-]

Yes. It is in the installation instructions. We have a piece of foam core in the office that actually melted when attached to a 90% furnace.

 

[Gregg Harris]

Was there any testing on the furnace to determine why the flue temperature was to high?

 

[ICE]

How do you identify this pipe? Does it state "foam core" on the pipe?

 

[Daddy-0-]

It usually says, " not for pressure. "

Foam core is approved for lots of installations but not all. Foam core doesn't like heat or pressure or loading. For instance, we do not allow it on the pressure side of a sewage ejector pit. Once it goes horizontal it is a drain and can be regular pipe.

 

[klarenbeek]

Approval or no approval come from the manufacturer, not the code (unless a local ordinance prohibits foam core). Most furnaces I have seen allow cell core pvc or even ABS. Most boilers do not, requiring only schedule 40 PVC. If cell core, the pipe should say "cell(ular) core" right on it. Another thing to check would be the ASTM listing of the pipe. Some manufacturers reference those as well.

 

[Papio Bldg Dept]

same viewpoint as Daddy-O- in our jurisdiction.

Greg...are you seeing it installed on 90% furnaces without failures?

 

[Gregg Harris]

Yes without failures if propeller installed and furnace is properly set up for airflow and combustion. I train in multiple jurisdictions and have companies tell me all the time that it is not approved by the inspectors.

It is in the IOM of all furnace manufactures and I was curios to see if there would be opinions. The flue temperature on a properly installed 90+ furnace should be in the 100 degree range with a max of 125 degrees. PVC "foam core/ cellular core" schedule 40 along with solid schedule 40 has a maximum allowable working temperature of 140.

I have not tested or seen one installed with schedule 40 ABS cellular core.

PVC foam core ASTM F891

ABS foam core ASTM F628

 

[steveray]

Just saw one on friday that had CPVC....still no foam core though....