To work properly, the bottom edge of the AAV needs to be at least 4 inches above the top of the drain trap.
AAV location
It must be located a minimum of 4” above the horizontal branch drain, 6” above any insulation material and within 15 degrees of vertical. AAVs cannot be permanently covered and should be installed in an area that allows air to enter the valve.
The AAV should be located: Within the maximum developed length permitted for the vent. A minimum of 4 inches above the horizontal branch drain.
When a Studor® valve is installed in an attic, it must be installed a minimum of 6” above insulation. The Studor valve must be installed a minimum of 4" above the horizontal branch the horizontal branch drain or fixture drain being vented.
Every vent shall rise vertically to a minimum of 6 inches above the flood level of the rim of the fixture being served.
For a 1 ½-inc pipe the vent should be 42 inches away at the most while a 2-inch pipe must have a maximum distance of 5 feet. For pipes that have a diameter of 3 inches the distance is 6 feet and for a 4-inch pipe the most it should be away from the vent is 10 feet.
How high should you install the air admittance valve? The short answer is a minimum of 200mm above any water entry point. So if you imagine your soil pipe run, then durgo valve / AAV must be fitted above the highest connection to the soil pipe from any sink, bath or toilet that is connected to it.
The stack-type AAV shall be located not less than 6 inches (152 mm) above the flood-level rim of the highest fixture being vented. The AAV shall be located within the maximum developed length permitted for the vent.
The Studor vent lets that air to be sucked in the pipe during water flow but doesn't let sewer gas escape out. Code is the thing that determines pipe size and also water flow. Hence no studor vents are permitted to toilets because more air is required to keep water flow going with more waste added to the toilet.
Air admittance valves are typically placed between the P-trap of a fixture and the drain line. They're usually mounted on one leg of a sanitary tee, with the other leg going to the drain. The unit must be placed per local codes and the manufacturer's instructions.
While it is possible to install an AAV hidden inside walls during remodeling work, it is more common to install them right under the sink cabinet as an adaptation of the pipe joining the drain trap to the branch drain.
Air admittance valves are not permitted in spaces where pressure conditions adversely affect the valve's operation. They are also not allowed in concealed wall and ceiling spaces used as plenums as part of an air distribution system that is under negative or positive pressure.
Yes. A vent is required so that the sewer gas can escape the house safely. The vent should always be located after the P-trap, not before it.
The AAV should be located a minimum of four inches above the horizontal branch wall tube. » Securing AAV: Measure and cut the PVC pipe appropriately. Solvent-weld the pipe into the adaptor using PVC cement, such as the Oatey® Heavy Duty Clear PVC Cement, which can be used for all PVC pipe and fittings.
Available in different sizes, AAVs can be used to vent an individual fixture, a complete branch, or an entire stack of vents.
The AAV is a one-way air valve which opens to allow air to flow into the system and balance the pressure. Once balanced, the valve will then close and create an airtight seal stopping any odours entering the building. By only opening one-way, the open valve draws in clean air, but stops any foul air escaping.
The other potential problem with using an AAV instead of a vent pipe is that if you ever get a blockage in the system that prevents the gasses from being pushed down into the sewer, those gases will have nowhere else to go.
Air admittance valves often feature rubber seals, to help create a complete seal, increasing the effectiveness of the valve and preventing any odours from escaping through small gaps.
How long does an AAV last? Adeno-associated viruses (AAVs) are stable for several months to years when stored properly at -80°C.
Individual and branch-type AAVs shall not be located not less than 4 inches (102 mm) above the horizontal branch drain or fixture drain being vented.
Types Of Backflow Devices
The RP device requires annual testing. Installation requirements: Install horizontally, a minimum of 12 inches and no more than 36 inches above finished grade. Must have adequate clearance on all sides for testing and maintenance.
Installing an air admittance valve
Having said that, some air admittance valves are designed for outside use. If that's what you want, check that the valve is kitemarked and rated for outside use in the UK, as a standard valve may not be suitable for frost, freezing temperatures or extreme weather conditions.
Horizontal vent pipes forming branch vents, relief vents or loop vents shall be at least 6 inches (150 mm) above the flood level rim of the highest fixture served and 42 inches (1067 mm) above finished floor.
Another way is field testing in a cup of water, Place the air admittance valve (AAV) in a cup as shown below. This creates a positive pressure which seals the membrane and allows the valve to float. If the AAV sinks then most likely the membrane has been compromised which allows air to pass through the AAV and sink.
According to the UPC, the distance between your trap and the vent should be no more than 6 feet. In other words, for the vent to work properly, it needs to feed into the drain line within 6 feet of the trapways that connect to it.