Questions on stove pipe bends and sizes.

[trucha]

I have two questions. One is a stove I am looking at has a rear exit only. Is it possible to connect a 90 bend directly to the collar? And the. Go strait up? Also it is an odd size. Can you go from 7 to the standard 6 in? At some point in the stove pipe?

 

[bholler]

if the collar is 7" the whole system really should be but i would bet that 6" would work ok. Also you can 90 at the back of the stove but do it with a tee not just an elbow