Air Admittance Valves

As soon as the valve detects a negative pressure (-0.01 psi) it opens to provide air passage into the valve from the room to satisfy the plumbing system drain vent negative pressure resulting in allowing proper air into the plumbing system as the waste flows down the drain.

The valve seals itself by gravity and at positive pressure (0 psi and above) to maintain a high-pressure seal. The valve can be used as a secondary alternative method to vent 1-1/2" or 2" DWV plumbing vent pipe for individual, branch and stack type vents.

(1) prevents sewer gases and odors from escaping inside a building and

(2) allows air to enter the plumbing system without the use of a vent extended to open air and 

(3) protects against siphonage of a plumbing fixture trap.

It must be installed in accordance with manufacturer’s installation instructions and local code requirements and always in an accessible location and remain accessible to allow free air passage and inspection.