Review on 💧 Oatey Sure-Vent AAV 1.5" 6 DFU Tubular Adapter (White) - One-Way Valve for Effective Plumbing Solutions by Matthew Kocur

Oatey 39225 is rated 6 DUF and fits 2" drainpipes. The vent valve is installed on tubular drain pipes located under the sink. Must be installed after the siphon. , and must be at least 2 pipe diameters from the siphon weir (the last bend in the siphon where the water in the siphon ends). , but 6 DUF is not designed for a shower and a bath, nor for 2 baths and not a toilet. A toilet, a washing machine or two bathtubs require 20 DUF. To comply with regulations, a home requires at least 1 DUF vent per a 3-4" roof ending outdoors above the home, typically 6" above the roof. Oatey 39225 must be installed in an upright position for proper ventilation. . Black vents are convenient 1-1/2" pipe threads but not the norm. The black vents are rated 1 DUF, fit in 1 sink, they often fail and get stuck in the open position if they fail (sewage gas into let home.) Oatey vents comply with regulations because after a failure, Oatey vents remain in the closed position and do not allow sewage gas into the home. Oatey 20 DUF models with 2" pipe thread. Oatey is certain that the vents under the sink should be open and cannot be sealed in the wall. If the vent is inside the wall, louvers will need to be added to allow air to enter. 39225 complies by placing the vent 4 inches above the top of the vertical drain line. 39225 requires 6" height for mounting. Therefore, measure from the top edge of the drain pipe. and if you have a gap greater than 6 inches between the top of the drain pipe and under the sink, Oatey 39225 will do. The 6 DUF vent valve attaches to the pipe drain with the included washer a and a standard pipe nut. Source: http://waterheatertimer.org/How-to-install-vent-under-sink.html