Plumbing Connection Winter 2022

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4 2 PLUMBING CONNECTION Winter 2022
Australian Standards AS3500.1-2021
Water Services and AS2845.2-2010
Part 2 specify that a break tank shall
have a minimum of 40 mm diameter
overflow pipe. (See Image 5.)
Some Automatic Refill Units do not
have the correct overflow pipe, with
some being as small as 20 mm.
Additionally, when choosing the
Automatic Refill unit, one should look
for the WaterMark symbol. It has been
reported that in some of the literature
that comes with the units and also
stickers found on some of the Refill
units, the manufacturer is promoting
the fact that there is no additional yearly
testing required, as the break tank has
an Integral Air Gap inside the tank.
ABOUT PETER
Peter Damaso has been
a licensed plumber since
1985 and has been an
accredited backflow
specialist since 1999. He
has sat on the NSW State
Committee of the Backflow
Prevention Association
of Australia Inc. since
2015 and has been an Executive Committee
Member since 2017. Peter is now the Vice-
President of the BPAA. Peter runs his own
backflow plumbing business and has extensive
knowledge of the backflow industry. Visit www.
to find out how the BPAA can help
you understand cross-connection control and
backflow prevention.
Footnotes:
In relation to AS/NZS 3500.1: 2021 several
backflow prevention provisions, which were
considered matters of public policy, have been
elevated to PCA Part B5 Cross Connection Control.
To remove duplication between PCA 2019 and AS/
NZS 3500.1, the provisions relating to cross-
connection hazards and the corresponding
hazard rating have been removed. This also avoids
inconsistencies between the cross-connection
hazards and the corresponding hazard rating in
AS/NZS 3500.1: 2021 and in NZBC Acceptable
Solution G12/AS1. Consequently, Appendix F has
been deleted and all remaining backflow provisions
have been consolidated in Section 4.
NCC 2022 and Volume 3, which is the PCA, are now
expected to be adopted by states and territories
from September 1, 2022.
BACKFLOW PREVENTION - PETER DAMASO
Image 2: In this picture the blue ball
valve is the main water supply, the
bottom green ball valve is the ‘quick-fill’
connection which has been incorrectly
hard-plumbed with copper pipe.
Image 5.
6. Remember that the Backflow
Prevention Association of Australia
(BPAA) is here to help members with
practical advice.
The BPAA is indebted to its member
Andrew Meade for providing the
research into this article and wish to
thank him for his time and effort.
This is correct ONLY IN LOW-HAZARD
applications. These systems, since they
contain chemicals to stop corrosion, are
a HIGH-RISK installation and thus MUST
have either a RPZD or a Registered Air
Gap (RAG) or a Registered Break Tank
(RBT).
AS3500 Section 4.4.6 states in part
that Registered Air Gaps and registered
break tanks shall only be used with
a maintenance program for device
registration and test certification.
The BPAA continues to use its
resources to educate its members
and the general public about the
difference between an Air Gap (AG) and
a Registered Air Gap (RAG), and a Break
Tank (BT) and a Registered Break Tank
(RBT).
The ‘Registered’ part of the Air Gap
and Break Tank is a record of information
that is recorded in a list or database for
the purpose of testing, and this is to be
done on an annual basis. If an Air Gap
is registered, a sign or a compliance
plate should be attached at or near the
Registered Air Gap, and the same with
the Registered Break Tanks with the
plate showing inlet orifice size, overflow
size, spill level and Air Gap dimensions.
Failure to have the correct backflow
device installed and tested annually
may affect the client’s public liability
insurance, should there be an incident.
WHAT CAN THE PROFESSIONAL
PLUMBER DO?
When installing these types of systems,
it is always vital to remember these
important steps.
1. Always make sure that the system
that you are installing carries the
Watermark Symbol.
2. Always following the Australian
Standards and the Plumbing Code of
Australia (PCA).
3. These types of installations that add
chemicals are a HIGH RISK, hence
they must have either a RPZD or a
Registered Air Gap or Registered
Break Tank.
4. As a HIGH HAZARD Risk installation
remember that a RPZD MUST also
be installed at the water meter as a
Containment device.
5. Check the type of Expansion Tank
membrane.
Image 3.
Image 4. Only EPDM rubber is approved
to be in contact with drinking water.