On my home made one I used CPVC, 3" pipe and have had no problems. CPVC is rated up to 212 degrees and it comes in both amber and black color. It is attached to my 10kw diesel generator and works fine, using Bill H's design.

quote:

Originally posted by Tom K:
On my home made one I used CPVC, 3" pipe and have had no problems. CPVC is rated up to 212 degrees and it comes in both amber and black color. It is attached to my 10kw diesel generator and works fine, using Bill H's design.

Thanks, I will look into that. Maybe if the lower portion was cpvc and the rest was thin wall it would be a good combination. I need more than the single 10' section of thin wall that I currently have to clear my roofline. 2 or 3 feet of that as the bottom section might tolerate the heat and the thin wall could work higher up where the temperatures are sure to be lower. I plan on trying it out tomorrow so I will post an update when I see the results.

quote:

Originally posted by Tom K:
On my home made one I used CPVC, 3" pipe and have had no problems. CPVC is rated up to 212 degrees and it comes in both amber and black color. It is attached to my 10kw diesel generator and works fine, using Bill H's design.

good to know ! None of the Lowes i was at had black - they had green (sewer) but no black.

iirc pvc is rated at around 160*

quote:

Originally posted by Bounding4:

quote:

Originally posted by Tom K:
On my home made one I used CPVC, 3" pipe and have had no problems. CPVC is rated up to 212 degrees and it comes in both amber and black color. It is attached to my 10kw diesel generator and works fine, using Bill H's design.

Thanks, I will look into that. Maybe if the lower portion was cpvc and the rest was thin wall it would be a good combination. I need more than the single 10' section of thin wall that I currently have to clear my roofline. 2 or 3 feet of that as the bottom section might tolerate the heat and the thin wall could work higher up where the temperatures are sure to be lower. I plan on trying it out tomorrow so I will post an update when I see the results.

Update number 1: I finished assembly of the rig last night and decided to torture test it. I could not find CPVC in anthing more than 1½". Seems to be almost an industrial application for anything like 3". What I did was get a short 3' section of schedule 40 pvc and cap the bottom end with a Selkirk 3" universal gas vent male adapter. It has a double wall construction that helps keep the outside from getting too hot and it accepts 3" scedule 40 PVC perfectly. Plus, the metal gives a much more solid hold for the screws that attace it to the exhaust side of the venturi. (I will include a picture when I get a chance)

Decided to torture test it for a while before mounting it on RV. Rarely does a genny's exhaust gasses exceed 750°F. I decided a Wagner heat gun I have should work as a stand in considering it is low temp setting is 750°F and 1000°F on high. Ambient temp was around 60°F when I started. I put the gun in the metal elbow where it will attach to the genny exhaust and let it run for 15 minutes on low. The metal below the venturi was absolutely blazing but the Selkirk adapter just 1.5" away across the venturi was cool enough to wrap my hands around. The PVC above that was slightly warmer but easily cool enough that I could have put my face against it. I attribute that to the double walled design of the metal.
Then I decided to put the heat gun on high for another 10 minutes. That did get the closest section of the metal adapter a little hotter but still touchable. The pipe actually did not get much hotter. I think the increased intake from the higher fan speed on the gun created a more cooling venturi effect. In both cases, tissue paper was easily blown out of the 13' tall column. I was duly impressed. Today it goes on for real. Will give pics and a final verdict then.

http://www.usplastic.com/catal...emid=23484&catid=521
Available here!

quote:

Originally posted by Tom K:
On my home made one I used CPVC, 3" pipe and have had no problems. CPVC is rated up to 212 degrees and it comes in both amber and black color. It is attached to my 10kw diesel generator and works fine, using Bill H's design.

i did use schedule 80 pipe, its what i had laying around in the garage, but mine was white (havent seen the gray)...and OTHERS have also used thick wall cpvc (shed 80) in WHITE w/ success.