How is 3" pipe measured.

[restorer]

I'm at my local source for cheap supplies today. They have overstocks, freight damaged and surplus buy-outs, etc. Getting my basics and looking around. On the metal stock rack are several pieces of 3 inch pipe. Now, I get a tape and measure them. 3inches OD, pipe walls are about 1/8 inch. It's marked 316 stainless. I'm thinking, perfect for for chimney lining. Well, the question is, can this be used to line a chimney? A collar would have to be made, but I think for the price it would be worth the effort. The pipe is 23 feet long, and the unbelievable price is $60.

 

[elkimmeg]

If you pellet stove takes 3' exhaust I find no reason for not using 316ti smooth pipe. What I would do is look into custom auto truck exhaust shop to make up the adapter sweeps and bends to feed into that pipe expand the 3" to fit your collar and decrease or expand exhaust pipe to and fittings to interface with your ss in the masonry chimney. Just an idea

got another idea what about feeding into a tee behind the stove which would make for easy clean outs

 

[MountainStoveGuy]

the problem i see is going verticle with 3 inch pipe. check your pellet stove manual, it will tell you when to convert to 4" money saved on the incorrect part will cost you money in combustion blowers if there is to much backpressure. Combustion blowers can range from $150-$250.

 

[elkimmeg]

Smooth pipe has less exhaust drag friction It is superior to corregated liner pipe in that aspect.
MSG is right check with your manual 4" may be needed if the run lenght is exceeded for using 3"