Chimney pipe comes in different types so make sure you are getting the correct one. If you have a wood stove or appliance that uses pellet or corn as fuel, you need to make sure you get pellet and corn rated chimney pipe. Chimney Caps usually are not tied into what fuel you use but more so the shape and type of chimney flue you have.
When you are getting stove pipe for your wood stove, make sure you get the correct diameter size or you can cause a disaster! Chimney liners are more straight forward but you need make sure you have a masonry chimney. Newer fireplaces and stoves tend to be direct vent or B vent stoves and fireplaces and do not need chimney liners.