self venting

[Cincinnati]

Would someone please explain or direct me to a self venting system. I am plaining to place my laundry room on my second floor which does not allow me to have excess to a venting stack.

thank you

[hj]

There can be as many interpretations as there are responders, since there may not be a specific definition for it. It could range from an aav fitting if the rest of the piping is correct, to an "improper", but functional, connection of the vent back to the vertical drain at a point where the vent would operate when it became necessary once most of the water has drained.