The 4" oval-to-round adapter with a 4" inner dimension is double walled and is used for many B vent exhaust applications. It can be used with natural gas or liquid propane, Category 1 appliances.
This vent pipe is 9.25". It can not
be cut for shorter lengths.
Some appliances that use Type B Gas Vent Systems include:
- Water Heaters
- Room Heaters
- Decorative Gas Appliances
- Unit Heaters