An Air Admittance Valve Shall be Acceptable as a Vent Termination for any Individual Vent, Common Vent, Circuit Vent, Loop Vent and Island Fixture Vent that is Provided to Prevent Siphonage of a Fixture Trap
An Air Admittance Valve Can be Used as an Alternative to Extending a Vent Through the Roof to the Open Atmosphere the Air Admittance Valve Shall be Located a Minimum of 4 Inch Above the Horizontal Branch Drain or Fixture Drain Being Vented
Each Valve Should be Installed in an Accessible Location Screening on the Inside and Outside of the Valve to Protect the Sealing Assembly from Insects and Debris will Vent Up to 20 DFUS on a Horizontal Branch and 24 DFUS on a Stack
