STUDOR® Air Admittance Valves
Group and Stack Venting
©MTW Studor Aust. Oct 2004
should at its completion, enable the participants to:
1.correctly identify the components of the Mini-Vent and Maxi-Vent Air Admittance Valve (AAV)
2.correctly install both in Group Venting and Stack Venting applications
will be via a written Question & Answer Sheet at the end of the course
(Participants are advised to make note of items marked with a ‘*’)
This is : “Group Venting”
This is “Stack Venting”
Airflow of7.5 litres/second at -250 Pa
*60 Fixture units for Group Venting
*6 Fixture units for Stack Venting
Airflow of 32 litres/second at -250 Pa
*1000 Fixture units for Group Venting
*140 Fixture units for Stack Venting
Both Valves have a lifetime warranty
Both conform to AN/NZS4936 Australian Manufacturing Standard
*.Always ensure when installing anyAAVthat it is an Australian Standards approved product and has both approval and airflow capacity(l/s) clearly marked on the body of the valve or packaging
On the top of the Mini-Vent and Maxi-Vent are the relevant Australian Standards Marking
Both AAV’s share a common form of packaging
POLYSTYRENE PACKAGING TOP FOR INSULATION
The Mini-Vent as supplied can beinstalled on 3 different sizes of PVC DWV pipes:
*The Mini-Vent can be installed up 1000mm(1 metre) below the rim/flood level of the highest fixture of the group it is venting
The capacity of the Mini-Vent is not limited by the pipe size it is connected to but the total number of fixture units it is venting.
i.e.: a Mini-Vent can be installed (via reducers etc.) on a 80mm (or above) DWV Waste Pipe if the total number of fixture units doesn’t exceed 60 F.U.
The Maxi-Vent as supplied can beinstalled on 2 different sizes of PVC DWV pipes:
*When used as a group vent the Maxi-Vent can also be installed up to 1000mm(1 metre) below the rim/flood level of the highestfixture in the group it is venting
This plumbing ventilation test rig, the biggest in the world, was built by students and staff at Gymea TAFE in Sydney, to prove AAVs were equal to or better than ‘Open Air Venting’ for groups of fixtures
This entire rig was vented by just 2
Clause 6.9 AIR ADMITTANCE VALVES
6.9.1 Air admittance valves
Air admittance valves complying with AS/NZS 4936 may be used in sanitary plumbing systems for *trap vents, group vents and stack vents and to ventilate branch drains*. They shall not be used for the upstream venting of a main drain.
NOTE: Branches connected into a positive pressure area, such as near boundary traps in multi storey buildings, may need additional venting.
6.9.2 Requirements for use
The following apply:
(a) Air admittance valves shall be used only on *systems that have at least one open upstream vent off the main drain. The upstream vent shall be sized in accordance with Table 3.5 and shall be not less than DN 50.
(b) Where more than one building on an allotment drains to the sewerage system, the sanitary drainage system of each building shall have one open upstream vent connected to its sanitary drain
(c) Air admittance valves shall have a determined airflow capacity not less than that in Table 6.6 when used as a trap vent, group vent or branch drain upstream vent, and Table 6.7 when used as a stack vent
.(d) An air admittance valve shall not be used as a stack vent where the stack extends through 10 or more floor levels.
(e) Where a sanitary plumbing system has a relief vent fitted to the stack, the relief vent shall be extended separately to atmosphere as an open vent.
(f) In Australia, air admittance valves that form an integral part of a fixture trap shall only be used as a trap vent
Here we see two options;
*1. Coming off the 100 x 50 vented Pan bend, (probably the last fixture in the group)
*2. Coming off a 100 x 50 Junction on the common discharge pipe
Relief Vent to atmosphere
* Common Discharge pipes
Clause 7.5.3 and 220.127.116.11.3(b)
Clause 18.104.22.168.2 (b)
Clause 22.214.171.124. 2
*Refer to Australian National Standards AS/NZS3500.2.2003
*Please note:Although group vents have been deleted, the relief vent is still required on the stack to maintain air flow and equalize pressures within the stack
Minimum Determined Airflow Capacity of Air Admittance Valves When used as a Trap or Group Vent
Fixture Unit loading of discharge pipe
Min. Airflow capacity of AAV’s
(litres per second)
The maximum capacity:
STUDOR® Mini-Vent™ 7.50 l/s (or 60 FU)
STUDOR® Maxi-Vent™ 32.01 l/s (or 1000 FU)
+ 6 x 1 F.U.(Washbasins)(6FU) = 30 FU
X 2 Floors
Let’s check the next table………..
MINIMUM DETERMINED AIRFLOW CAPACITY OF AIR
ADMITTANCE VALVES VENTING DISCHARGE STACKS
Fixture unit loading of discharge Minimum determined air flow
stack capacity of AAV, Litres per second
Push-fit into 100mm DWV
pipe with adapter
Removal of adapter enables
solvent welding to 80mm DWV
Adapter allows push-fit over 80mm DWV pipe
No need to penetrate the roof!
When a Maxi-Vent is installed in a roof space, always allow at least 150mm above any insulation
When installing the Maxi-Vent in areas that might be subject to temperatures below 0ْ or above 60ْ, use the top half of the foam packaging for thermal protection ْ
For additional physical protection, where the valve is installed externally, an aluminum cap is available as an cover over the foam packaging.
Traditionally Vented plumbing system
A stack and group vented plumbing system using Studor AAV’s
Note the saving of unnecessary vent piping/fire collars etc and no roof penetration required
*Although not shown here, each plumbing system/building/house etc must have at least one open vent to atmosphere.
In some cases this may need to be the main stack, so a Maxi-vent might not be used.
Mini-Vents would still be used however for venting single fixtures and bathroom groups
STUDORAustralia would like to thank:
- the Teaching and Stores Staff under the guidance of Raymond Jones, Senior Head Teacher of Plumbing,TAFE NSW Southern Sydney Institute, Sutherland College (Gymea Campus)
for their support and contribution to this entire course.
- All TAFE teachersnationally
STUDOR would also like to acknowledge the continued support offered by Plumbers Supplies Co-operative who provided the materials for this project