the is was my first season burning pellets, so I swept out pipe today. In doing do, o realized the rubberlike gasket at the clean out was misshapen in one spot, as shown in pic. I have a cleanout on the inside of room and outside a long my foundation wall. The cleanout outside was normal so I swapped them out (thinking I’d rather have something not quite right on the outside of house rather that inside right next to stove). I’m not sure what the lifetime of these gaskets is or if they are replaceable. Pipe is Ventis Pellet Vent.