Studor air admittance valve’s (AAVs) are used as a method for venting traps for fixtures and waste receptors. AAVs reduce the amount of vent piping required to terminate outdoors. An AAV is designed to open to admit air into the venting and drainage system when negative pressures (less than atmospheric pressure) occur in the vent system. An AAV closes by gravity to seal the vent terminal when the vent system pressure is equal to atmospheric pressure. At vent system pressures greater than atmospheric pressure, an AAV remains closed and seals tighter under greater pressure by the nature of the design. The closed AAV prevents any vapor in the vent system from entering the building.
AAVs are required to conform to one of three ASSE standards. Stack-type air AAVs shall conform to ASSE 1050. Individual and branch-type AAVs shall conform to ASSE 1051. AAVs shall not be installed in non-neutralized special waste systems as described in Chapter 8 of the International Plumbing Code (IPC) except where such valves are in compliance with ASSE 1049, are constructed of materials approved in accordance with Section 702.5 of the IPC and are tested for chemical resistance in accordance with ASTM F 1412. Air admittance valves shall not be located in spaces utilized as supply or return air plenums. Air admittance valves without an engineered design shall not be utilized to vent sumps or tanks of any type.
The Studor Mini-Vent®, Maxivent®, Redi Vent®, Tec-Vent® must be installed in accordance with the manufacture’s installation instructions and the conditions noted in the ICC-ES PMG Product Certificate PMG-1025.