Chimney advice

I am planning my rehabilitate efm 520and would like some advice from the great members of this hot forum. I am half a bubble out of plumb and i will be using as my chimney, if I get your approvals a 10 " diam sch 10 pipe that i will use as the center post of a circular staircase that is out doors. I will line the pipe with stainless chimny liner. The question is should i insulate this 25 feet high pipe. This pipe fits into my architechural ual program I think i may need to insulate. but of course its added labor and cost.

also I have access to sch 10 2 inch stainless pipe. If I use that for the auger casing wiill the difference in the id from sch 40 adversely affect auger operation
and.


I also have acquired a 8 foot auger screw. what are the visual characteristes of a worn screw. what I have is concentric and no weldments. the edges of the auger have a flat land and not knife edge. the four footer that is in the pot has knife sharp edges , please advise

I am a building little room under a building to house the efm, that is one of the needs of the out door spiral stair
thanks and this is a great forum. hot to say the least

Your flue pipe is supposed to be 8 inch, so that leave you with a perfect area to use cerofelt insulation. I probably would insulate, if it were mine. Use 316 stainless.

I'm not familiar with your coal pipe size, but you don't want alot of space around the OD of the worm, or grinding will occur and create alot of dust and maybe strain on the worm and shear pins. Not good.

As long as the edges of the worm are flat, you're OK. Sharp edges are no good.

I will admit that I participate in other heating forums, to a much lesser extent, but this site is by far the best of any forum I've ever been on.