Air admittance valve (AAV) - 3" to 4"

Air admittance valve (AAV) - 3” to 4”: This line item refers to the installation or replacement of an air admittance valve (AAV) with a diameter of 3” to 4”. This larger AAV is used in plumbing systems to regulate air pressure within larger drainage pipes, ensuring proper flow and preventing the escape of sewer gases into the building.