I guess there would not be enough room for your vent pipe to pass through?
Better draft, better for the masonry flu gases can damage it, required by manufacturer
No b-vent is double wall rigid gas pipe. Flexible liners are not b vent they are simply liners
That sounds like what they put in for my natural gas fireplace a year after my chimney fire.
Call it what you like. They are vent liners for bvent appliances. The box says bvent liner lol. I know what "bvent" is to. It's possible they have an old unlined brick chimney with poor mortar.
I have been in the industry about 20 years now and have never heard a liner called b vent. And yes of course they need a liner even if its got a good clay liner
Yeh neither have I. I think we both know what bvent is. But the kits we use to vent a bvent appliance through a chimney are usually specifically for bvent appliances due to their diameter and lack of a direct vent liner. I'm pretty sure they are labeled as such. I'm not calling a bvent liner bvent. I'm calling it a bvent liner. That's why I mentioned this because he shouldn't have trouble fitting a 4" bvent liner through a 5" throat. Every bvent stove and insert I work on is vented via a 4" liner. Maybe he is trying to install actual bvent through his chimney. If that is the case I'm puzzled as well
Who knows. Without knowing the appliance and required venting we are just guessing. I think bholler and myself were trying to say the same thing but using slightly different terminology for flexible liners that are used for bvent appliances in masonry chimneys. If it's a bvent insert I would use a flexible liner connector to the insert. If it was a free standing stove I would use flexible liner to the stove but also use a section of smoke pipe to cover it if visible.
