Inner Wall on Double Wall Pipe

Hi everyone, new guy here. I just started burning wood this year and i love it! I have a Century Heating "Whistler" wood stove. I have a through the roof installation. I have single walled black pipe going from the stove to the ceiling box then Super-Vent double walled insulated twist lock chimney pipe from there up. Everything works great, awesome heat! Im really paranoid so i clean my chimney out once a month. Well i cleaned it out last night and what i do is take the black pipe apart from the stove to the ceiling and clean those peices individually then run my brush up through the chimney. Well i noticed last night that inner wall of the double walled pipe sticks inward at the seam. The seam of the inner wall looks like the snap together type like the black pipe is. Well it almost looked like i could see in behind the inner wall at the seam and see the insulation. Is it normal for the seam to pertrude inward, and is it hurting anything if the really hot air gets in behind the inner wall? i would think that after a good daught starts that it would be pulling inward, not letting anything in behind. Any thoughts?

No, im at work and saw it last night. I was going to stop at lowes after work and look at a new peice and see what it looks like. I was just worried about the flammability of the insulation inside, and would smoke be able to seep out anywhere. Also to make it more clear, it was at the end of the section of chimney, so the very end of the seam was popping in. It was in arms length and i was able to take a tiny hammer and tap it in, but im a paranoid fella and am just worried. Maybe it wasnt insulation, maybe i was just seeing things. Any thoughts

Well can anyone tell me is the insulation fire retardant in between the walls? Its not like its going to be right next to fire, its 5 1/2 feet up the chimney from the top of the stove. I wouldnt think that smoke would be able to work in there and go anywhere.

Ill try to snap a few tonight.

Ok, i went to lowes (where i bought the chimney pipe) and looked at some new peices, and they seem to have the same characteristics as the installed peices. Looks like the bottom end of the inner wall, where the laser weld is, is bent inward slightly, exposing some insulation. I peiced some peices together at lowes to see it and it looks just like mine. So i have two connections in my chimney where i could see it was bent in. Luckily I was able to reach in the chimney and use a small hammer to flatten it back straight and flush. After i was looking at the new peices and my chimney i dont think it was hurting anything, the twist lock flanges were sealing everything, and the area behind the bent in wall was still clean telling me that the creosote and smoke was not going in there. Here are some pics i took. Sorry, they are on my phone.

This is a new peice and you can see on the seem its it bent in a little exposing some insulation. Tapping it flat with a hammer closes off the gap where the insulation is showing.


Here are two new peices put together at lowes and you can see the slight inward bent area by the inner wall seam.


Here is a bad picture of inside my chimney. The really bright spot is where the slight inward bent area is. I used a small hammer to flatten back flush.


And finally here is a picture of my stove. I love it. This stove has already paid for itself in the amount of money i havent had to pay for oil this year already. And its only February. I put a sheild on my black pipe cause i get over paranoid like that.


So i think im fine now that i flattened it back flush. It just caught me by suprise while cleaning last night. Oh and did i mention i love my wood stove. The heat, the smell, and just the pick me up it seems to give you on those cold dreary winter days.

Good, cause i sort of forgot about this, never had a problem last year, and have been burning this year as well. But all seems good, and i did sort of think about the negative pressure thing too.