This one-way mechanical device opens to let air into a plumbing drainage system when negative pressure occurs, preventing the water in fixture traps from being siphoned out. Once the pressure equalizes, it seals shut to block foul sewer gases from entering the living space. It is often used in island sinks or remodels where running a traditional vent pipe to the roof is impractical.
Heard on the job
The inspector flagged the island sink because the air admittance vent was installed too low below the flood rim.
Also heard as
- air admittance valve
- AAV
- Studor vent