Plastic for furnace....vent ducting

The plastic looked like some type of heavy duty PVC…would add a pic but I’m in the field… on my cell phone

Is this a new acceptable material?


It’s used for high effieciency furnaces.

Concentric vent is plastic on HE units condensation free piping. Is it a Rinnai?

When I get home I’m going to add pics…
I have never seen before…