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gravity-activated they can protect water-trap seals from failing due to "negative pressure" fluctuations. ` • AAVs are pressure activated, and placed close to the fixture, to immediately increase airflow when there is a drop in pressure,preventing water from being sucked away from the trap seal. • AAVs do not protect against"positive pressure" events; accordingly,AAVs need to be installed along with at least one roof vent. • Studies show AAVs have an advantage in wet environments because they require fewer exterior roof penetrations. Documentation of this is incorporated by reference. • AAVs arc listed by IAPMO, ITS, ICC Evaluation Services Inc., CSA, and UL. AAVs meet the national consensus standards for materials,NSF 14-2009, and national consensus performance standards ASSE No. 1050-2009 and 1051-2009. • The ASSE standards require testing for endurance, air tightness,pressure containment, and frost closure and are incorporated by reference. Scope of ruling: Following consideration of standards promulgated by entities that publish model codes in use by Oregon, the division rules that AAVs are conditionally acceptable for the construction, alteration, and repair of detached one- and two-family dwellings and townhouses and row houses,not more that three stories above-grade in height with a separate means of egress, and their accessory structures. The acceptability of AAVs as an alternate material are contingent on construction meeting the following conditions: 1. The alternative use of AAVs for plumbing venting are in addition to the other requirements of the Oregon Plumbing Specialty Code. thr 2. Each AAV may function as a vent for a maximum of three (3) fixtures, and may function as a vent for two (2), or three(3), fixtures, only if those fixtures are part of a plumbing fixture grouping such as a bath,kitchen or laundry area, and all fixtures in the grouping are located on a single level within the dwelling. 3. AAVs shall be rated in accordance with the standard for the size of the vent to which the valve is connected. 4. AAVs shall be located not less than four(4) inches (102 mm) above the fixture drain being vented. 5. AAVs shall be located within the maximum developed length permitted for the vent connection. 6. Access shall be provided to all AAVs for inspection, maintenance and removal. The valve shall be located within a ventilated space that allows air to enter the valve. 7. Each plumbing system shall have at least one stack vent extending outdoors to the open air, as required by the Oregon Plumbing Specialty Code. 8. AAVs shall not be installed to serve sumps, chemical wastes, or in supply or return air plenums. 9. AAVs must meet the NSF 14-2009 standard as well as either the ASSE 1050-2009 standard or the 1051-2009 standard. Conclusion: After considering the technical and scientific approval by the Oregon State Plumbing Board, the division rules that AAVs are acceptable as a construction method, subject to the stated limitations, and 41/ the revised Alternate Method Ruling OPSC 07-01 is approved. Page 3 of 4