mystery vent pipe gasket

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New Member
Oct 11, 2022
Performing the last of the preseason maintenance (this is our second year living in Vermont with a Harman P61 pellet stove), I cleaned out the exhaust vent pipe today. Our stove vents horizontally through the wall. I removed the vent cap outside and ran the wire cleaning brush through from the stove to the end of the vent outside. When I did so, however, I managed to pop an orange gasket (silicone?) off of the end of the vent pipe termination. Couldn't for the life of me get it back on the pipe, and in the process of trying to stretch it to fit on the end I managed to rip it. Anybody have experience with this? Is this supposed to close the gap between the two layers of vent pipe? Or form a weathertight seal between the vent pipe and the vent cap?

I think this might be the same thing:

But if it is, I am at a loss about how to attach it properly. Any help would be greatly appreciated!

Could you post a pic or 2 of the pipe connections affected?
Thanks for the reply. I think I figured it out . . . see pictures below. The orange flange seems to fit in a groove just inside the end of the outlet pipe, securing and sealing the link between the outlet pipe and the cap vent sleeve. Now that I've ripped the flange, though, I need to figure out where to find a replacement. I thought it was an ICC pipe, but looks like it could also be a Ventis or a Rock-Vent, judging from some pics that I'm finding online.

mystery vent pipe gasket mystery vent pipe gasket mystery vent pipe gasket
You probably could send a picture, with dimensions, to woodsmans or ESES and they could tell quite quickly what brand it is.
If that seal is at the end of the pipe outside (other than the cap) why bother with a new seal
If it leaks a little so what! What will it hurt?
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You could even run a bead of red RTV around where the gasket is supposed to rest, let it vulcanize a bit then put it back together
Thank you, all, for your thoughts. I've had it back together with the old gasket in place, and everything is running fine, inside and out, so I think I'm going to leave it for now. My sense is that this would only be an issue if this section of pipe was running inside the house. If it becomes a problem, I'll go to plan B (RTV or new gasket).

Thanks again!
Unfortunately,I disagree with some here. That gasket also keeps "smoke" from getting between the 2 pipe layers. So if you get a smoke smell and cannot find the cause, you know whee to start. But, being such a short run, you may never have a problem.
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