Proponents of air admittance valves want them added to the UPC code, but they face resistance from those who remain unconvinced.
A recent survey among readers of PM Engineer magazine revealed that 74 percent would consider the use of AAVs for venting systems, while 52 percent said they would use AAVs anywhere the code would allow. Currently, AAVs that comply to American Society of Sanitary Engineering (ASSE) 1050, 1051 and NSF Standard 14 are approved in the International Plumbing codes (IPC/IRC). But the Uniform Plumbing Code (UPC) only allows them under Section 301.2, Alternate Materials and Methods--and only when approved by the authority having jurisdiction.