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AS/NZS 2845.1:2022


Water supply — Backflow prevention devices, Part 1: Materials, design and performance requirements

AS NZS 2845.1 sets out requirements for the materials, design, performance and testing of mechanical backflow prevention devices that are used for the protection of water supplies, for health and safety and protection of the environment.
Published: 27/05/2022
Pages: 152
Table of contents
Cited references
Content history
Table of contents
About this publication
1 Scope and general
1.1 Scope, demonstration of conformance and application
1.1.1 Scope
1.1.2 Product conformity evaluation
1.1.3 Application
1.2 Normative references
1.3 Terms and definitions
1.4 Testing apparatus, testing sequence and instrumentation
1.5 Designation of size
1.6 Classification
1.7 Allowable pressures
2 Materials
2.1 General
2.2 Stainless steel
2.3 Filler metals for brazing or soldering
2.4 Nickel-copper-iron
2.5 Ferrous materials
2.5.1 General
2.5.2 Coating design
2.6 Copper
2.7 Copper alloy
2.8 Aluminium alloys
2.9 Corrosion-resistant metallic materials
2.10 Elastomeric materials
2.11 Plastics
2.11.1 General
2.11.2 Plastics-bodied devices
2.11.3 Acetal
3 Common design and performance requirements
3.1 General
3.2 Effect on water
3.3 Pressure and temperature ranges
3.4 Design
3.4.1 Serviceability
3.4.2 Release of trapped air
3.4.3 Flexible valve seats and diaphragms
3.5 End connections
3.5.1 General
3.5.2 Hose connections
3.5.3 Test tap outlets
3.5.4 Water meter connection ends
3.6 Valve seating
3.7 Structural tests
3.7.1 General
3.7.2 Torque
3.7.3 Heated water
3.7.4 Positive pressure
3.7.5 Reverse pressure
3.7.6 Endurance
3.7.7 Non-testable devices (low hazard)
3.8 Sampling and frequency plans
4 Atmospheric vacuum breaker (AVB)
4.1 General
4.2 Components
4.2.1 Ventilation valve
4.2.2 Non-return valve
4.3 Specific design requirements
4.3.1 Air port shields
4.3.2 Critical level (CL) mark
4.4 Performance tests
4.4.1 Procedures
4.4.2 Air port opening area
4.4.3 Water rise
4.4.4 Rated flow and pressure loss
4.4.5 Ventilation valve leakage
4.4.6 Critical level
4.4.7 Endurance
4.4.8 Ability to resist adhesion between the ventilation valve sealing elements
4.5 Sampling and frequency plans
5 Hose connection vacuum breaker (HCVB)
5.1 General
5.2 Components
5.2.1 Ventilation valve
5.2.2 Non-return valve
5.3 Specific design requirements
5.3.1 Air ports locations
5.3.2 Air ports opening area
5.3.3 Security
5.4 Performance tests
5.4.1 Procedures
5.4.2 Leakage from air ports
5.4.3 Resistance to bending
5.4.4 Ability to resist and relieve backpressure
5.4.5 Backpressure
5.4.6 Back-siphonage
5.4.7 Rated flow and pressure loss
5.4.8 Endurance
5.5 Sampling and frequency plans
6 Dual check valve with atmospheric port (DCAP)
6.1 General
6.2 Components
6.2.1 Ventilation valve
6.2.2 Non-return valves
6.3 Specific design requirements
6.3.1 Airflow passage, cross-sectional area
6.3.2 Air port outlet
6.4 Performance tests
6.4.1 Procedures
6.4.2 Non-return valve closing pressure
6.4.3 Leakage from air ports
6.4.4 Backflow through upstream non-return valve
6.4.5 Ventilation valve opening pressure
6.4.6 Back-siphonage
6.4.7 Back-siphonage under backpressure
6.4.8 Rated flow and pressure loss
6.4.9 Flow with low supply pressure
6.4.10 Endurance
6.5 Sampling and frequency plans
7 Dual check valve (dual CV)
7.1 General
7.2 Components
7.3 Performance tests
7.3.1 Procedures
7.3.2 Non-return valve closing pressure
7.3.3 Rated flow and pressure loss
7.3.4 Endurance
7.4 Sampling and frequency plans
8 Dual check valve with intermediate vent (Du CV)
8.1 General
8.2 Components
8.2.1 Ventilation valve
8.2.2 Non-return valves
8.3 Specific design requirements
8.3.1 Air port locations
8.3.2 Air ports opening area
8.4 Performance tests
8.4.1 Procedures
8.4.2 Non-return valve closing pressure
8.4.3 Minimum flow capacity and pressure loss
8.4.4 Intermediate vent device leakage
8.4.5 Back-siphonage
8.4.6 Endurance
8.5 Sampling and frequency plans
9 Pressure type vacuum breaker (PVB)
9.1 General
9.2 Components
9.2.1 Ventilation valve
9.2.2 Non-return valve
9.2.3 Test taps
9.3 Specific design requirements
9.3.1 Air port shields
9.3.2 Test taps
9.3.3 Critical level mark
9.4 Performance tests
9.4.1 Procedures
9.4.2 Non-return valve closing pressure
9.4.3 Ventilation valve opening pressure
9.4.4 Air port opening area
9.4.5 Water rise
9.4.6 Rated flow
9.4.7 Critical level
9.4.8 Endurance
9.4.9 Ability to resist adhesion between the ventilation valve sealing elements
9.5 Sampling and frequency plans
10 Double check valve (DCV)
10.1 General
10.2 Components
10.2.1 Non-return valve
10.2.2 Test taps
10.3 Specific design requirements
10.4 Performance tests
10.4.1 Procedures
10.4.2 Non-return valve closing pressure
10.4.3 Rated flow
10.4.4 Endurance
10.5 Sampling and frequency plans
11 Double check detector assembly (DCDA)
11.1 General
11.2 Components
11.2.1 Main double check valve
11.2.2 Bypass line
11.2.3 Water meter
11.2.4 Secondary double check valve
11.3 Performance test
11.3.1 Procedures
11.3.2 Pressure drop
11.3.3 Endurance
11.4 Sampling and frequency plans
12 Reduced pressure zone device (RPZD)
12.1 General
12.2 Components
12.2.1 Non-return valves
12.2.2 Relief valve
12.2.3 Test taps
12.3 Specific design requirements
12.3.1 Relief valve diaphragm or equivalent
12.3.2 Test taps
12.3.3 Relief valve opening
12.4 Performance tests
12.4.1 Procedures
12.4.2 Downstream non-return valve closing pressure
12.4.3 Intermediate chamber pressure
12.4.4 Supply pressure at which the intermediate chamber becomes atmospheric
12.4.5 Intermediate chamber pressure under backpressure conditions when the supply pressure is 14 kPa or greater
12.4.6 Intermediate chamber pressure under backpressure conditions, when the supply pressure is less than 14 kPa
12.4.7 Pressure differential at which relief valve commences to open
12.4.8 Supply pressure fluctuations and discharge from relief valve
12.4.9 Rated flow and pressure loss
12.4.10 Back-siphonage
12.4.11 Backpressure
12.4.12 Endurance
12.5 Sampling and frequency plans
13 Reduced pressure detector assembly (RPDA)
13.1 General
13.2 Components
13.2.1 Main reduced pressure zone valve
13.2.2 Bypass line
13.2.3 Water meter
13.2.4 Secondary reduced pressure zone device
13.3 Performance test
13.3.1 Procedures
13.3.2 Pressure drop
13.3.3 Endurance
13.4 Sampling and frequency plans
14 Spill-resistant pressure vacuum breaker (SPVB)
14.1 General
14.2 Components
14.2.1 Ventilation valve
14.2.2 Air port entry seal
14.2.3 Non-return valve
14.2.4 Test points
14.3 Specific design requirements
14.3.1 Air port shields
14.3.2 Test points
14.4 Performance tests
14.4.1 Procedures
14.4.2 Non-return valve closing pressure
14.4.3 Ventilation valve opening pressure
14.4.4 Air port entry seal
14.4.5 Air port opening area
14.4.6 Water rise
14.4.7 Rated flow and pressure loss
14.4.8 Critical level
14.4.9 Ability to resist adhesion between the ventilation valve sealing elements
14.4.10 Endurance
14.5 Sampling and frequency plans
15 Beverage dispenser dual check valve with atmospheric port (BDDC)
15.1 General
15.2 Components
15.2.1 Ventilation valve
15.2.2 Non-return valves
15.2.3 Air port
15.3 Specific design requirements
15.3.1 Air port
15.3.2 Air port shields
15.3.3 Air port opening area
15.3.4 Strainers
15.4 Performance tests
15.4.1 Procedures
15.4.2 Non-return valve closing pressure
15.4.3 Air port leakage
15.4.4 Backflow through upstream non-return valve
15.4.5 Ventilation valve opening pressure
15.4.6 Back-siphonage under backpressure
15.4.7 Rated flow and pressure loss
15.4.8 Ability to withstand continuous pressure
15.4.9 Endurance
15.5 Sampling and frequency plans
16 Pipe interrupter device (PID)
16.1 General
16.2 Components — Air inlets
16.3 Specific design requirements
16.3.1 Air ports
16.4 Performance test
16.4.1 Procedures
16.4.2 Torque test for screwed end devices
16.4.3 Air inlets
16.5 Sampling and frequency plans
17 Single check valve (testable) (SCVT)
17.1 General
17.2 Components
17.2.1 Non-return valve
17.2.2 Test taps
17.3 Specific design requirements
17.4 Performance tests
17.4.1 Procedures
17.4.2 Non-return valve closing pressure
17.4.3 Rated flow and pressure loss
17.4.4 Endurance
17.5 Sampling and frequency plans
18 Single check detector assembly (testable) (SCDAT)
18.1 General
18.2 Components
18.2.1 Main single check device
18.2.2 Bypass line
18.2.3 Water meter
18.2.4 Secondary check device
18.3 Performance tests
18.3.1 Procedures
18.3.2 Pressure drop
18.3.3 Endurance
18.4 Sampling and frequency plans
19 Marking and packaging
19.1 Marking
19.1.1 On the device
19.1.2 Nameplate or label
19.2 Packaging
20 Manufacturer’s data
20.1 Installation instructions
20.2 Maintenance instructions
Appendix A
A.1 Scope
A.2 Relevance
A.3 Terms and definitions
A.4 Testing
A.4.1 Type testing
A.4.2 Batch release test
A.4.3 Retest
A.5 Sampling and frequency plans — Type tests and batch release tests
A.5.1 Atmospheric vacuum breaker (AVB)
A.5.2 Hose connection vacuum breaker (HCVB)
A.5.3 Dual check valve with atmospheric port (DCAP)
A.5.4 Dual check valve (Dual CV)
A.5.5 Dual check valve with intermediate vent (Du CV)
A.5.6 Pressure type vacuum breaker (PVB)
A.5.7 Double check valve (DCV)
A.5.8 Double check detector assembly (DCDA)
A.5.9 Reduced pressure zone device (RPZD)
A.5.10 Reduced pressure detector assembly (RPDA)
A.5.11 Spill-resistant pressure vacuum breaker (SPVB)
A.5.12 Beverage dispenser dual check valve with atmospheric port (BDDC)
A.5.13 Pipe interrupter device (PID)
A.5.14 Single check valve (testable) (SCVT)
A.5.15 Single check detector assembly (testable) (SCDAT)
Appendix B
B.1 Testing apparatus
B.1.1 Pressurizing system
B.1.2 End connections
B.1.3 Torque wrenches
B.1.4 Timing devices
B.1.5 Sight glass
B.1.6 Isolating valves
B.1.7 Testing environment
B.1.8 Conditioning of test devices
B.1.9 Fouling wires
B.1.10 Tolerances
B.2 Testing sequence
B.3 Instrumentation
B.3.1 General
B.3.2 Flow meter — For use with air
B.3.3 Flow meter — For use with water
B.3.4 Pressure gauge
B.3.5 Temperature-indicating device
B.3.6 Timing device
B.3.7 Sight glass
B.3.8 Failure of device during testing
Appendix C
C.1 Scope
C.2 Testing temperature
C.3 Apparatus
C.4 Procedure
C.5 Test report
Appendix D
D.1 Scope
D.2 Testing temperature
D.3 Apparatus
D.4 Procedure
D.5 Test report
Appendix E
E.1 Scope
E.2 Testing temperature
E.3 Apparatus
E.4 Procedure
E.5 Test report
Appendix F
F.1 Scope
F.2 Testing temperature
F.3 Apparatus
F.4 Procedure
F.5 Test report
Appendix G
G.1 Scope
G.2 Testing temperature
G.3 Apparatus
G.4 Procedure
G.5 Test report
Appendix H
H.1 Scope
H.2 Testing temperature
H.3 Apparatus
H.4 Procedure
H.5 Test report
Appendix I
I.1 Scope
I.2 Testing temperature
I.3 Apparatus
I.4 Procedure
I.5 Test report
Appendix J
J.1 Scope
J.2 Testing temperature
J.3 Apparatus
J.4 Procedure
J.5 Test report
Appendix K
K.1 Scope
K.2 Testing temperature
K.3 Apparatus
K.4 Procedure
K.5 Test report
Appendix L
L.1 Scope
L.2 Testing temperature
L.3 Apparatus
L.4 Procedure
L.5 Report
Appendix M
M.1 Scope
M.2 Testing temperature
M.3 Apparatus
M.4 Procedure
M.5 Test report
Appendix N
N.1 Scope
N.2 Testing temperature
N.3 Apparatus
N.4 Procedure
N.5 Test report
Appendix O
O.1 Scope
O.2 Testing temperature
O.3 Apparatus
O.4 Procedure
O.5 Test report
Appendix P
P.1 Scope
P.2 Testing temperature
P.3 Apparatus
P.4 Procedure
P.5 Test report
Appendix Q
Q.1 Scope
Q.2 Testing temperature
Q.3 Apparatus
Q.4 Procedure
Q.5 Test report
Appendix R
R.1 Scope
R.2 Testing temperature
R.3 Apparatus
R.4 Procedure
R.5 Test report
Appendix S
S.1 Scope
S.2 Testing temperature
S.3 Apparatus
S.4 Procedure
S.5 Test report
Appendix T
T.1 Scope
T.2 Testing temperature
T.3 Apparatus
T.4 Procedure
T.5 Test report
Appendix U
U.1 Scope
U.2 Testing temperature
U.3 Apparatus
U.4 Procedure
U.5 Test report
Appendix V
V.1 Scope
V.2 Testing temperature
V.3 Apparatus
V.4 Procedure
V.5 Test report
Appendix W
W.1 Scope
W.2 Testing temperature
W.3 Apparatus
W.4 Procedure
W.5 Test report
Appendix X
X.1 Scope
X.2 Testing temperature
X.3 Apparatus
X.4 Procedure
X.5 Test report
Appendix Y
Appendix Z
Z.1 Scope
Z.2 Testing temperature
Z.3 Apparatus
Z.4 Procedure
Z.5 Test report
Appendix AA
AA.1 Scope
AA.2 Testing temperature
AA.3 Apparatus
AA.4 Procedure
AA.5 Test report
Appendix BB
BB.1 Scope
BB.2 Testing temperature
BB.3 Apparatus
BB.4 Procedure
BB.5 Report
Appendix CC
CC.1 Scope
CC.2 Testing temperature
CC.3 Apparatus
CC.4 Procedure
CC.5 Test report
Appendix DD
DD.1 Scope
DD.2 Testing temperature
DD.3 Apparatus
DD.4 Procedure
DD.4.1 Pressure type vacuum breaker and spill-resistant pressure vacuum breaker
DD.4.2 Vacuum breaker check device
DD.4.3 Test report
Appendix EE
EE.1 Scope
EE.2 Testing temperature
EE.3 Apparatus
EE.4 Procedure
EE.5 Report
Appendix FF
FF.1 Scope
FF.2 Testing temperature
FF.3 Apparatus
FF.4 Procedure
FF.5 Test report
Appendix GG
GG.1 Scope
GG.2 Testing temperature
GG.3 Apparatus
GG.4 Procedure
GG.5 Test report
Appendix HH
HH.1 Scope
HH.2 Testing temperature
HH.3 Apparatus
HH.4 Procedure
HH.5 Test report
Appendix II
II.1 Scope
II.2 Temperature of measurement
II.3 Apparatus
II.4 Procedure
II.5 Test report
Appendix JJ
JJ.1 Scope
JJ.2 Temperature of measurement
JJ.3 Apparatus
JJ.4 Procedure
JJ.5 Test report
Appendix KK
KK.1 Scope
KK.2 Temperature of measurement
KK.3 Apparatus
KK.4 Procedure
KK.5 Test report
Appendix LL
LL.1 Scope
LL.2 Temperature of measurement
LL.3 Apparatus
LL.4 Procedure
LL.5 Test report
Appendix MM
MM.1 Scope
MM.2 Temperature of measurement
MM.3 Apparatus
MM.4 Procedure
MM.5 Test report
Appendix NN
NN.1 Scope
NN.2 Temperature of measurement
NN.3 Apparatus
NN.4 Procedure
NN.5 Test report
Appendix OO
OO.1 Scope
OO.2 Temperature of measurement
OO.3 Principle
OO.4 Application
OO.5 Apparatus
OO.6 Procedure
OO.7 Test report
Appendix PP
PP.1 Scope
PP.2 Temperature of measurement
PP.3 Apparatus
PP.4 Procedure
PP.5 Report
Appendix QQ
QQ.1 Scope
QQ.2 Temperature of measurement
QQ.3 Principle
QQ.4 Apparatus
QQ.5 Procedure
QQ.6 Report
Appendix RR
RR.1 Scope
RR.2 Temperature of measurement
RR.3 Apparatus
RR.4 Procedure
RR.5 Report
Appendix SS
SS.1 Scope
SS.2 Composition
SS.2.1 General
SS.2.2 Reprocessable material
SS.2.3 Plastics-moulded material test
SS.2.4 Plastics-bodied device test
SS.2.5 Opacity test
SS.2.6 UV resistance
SS.3 Freedom from defects
SS.4 Threaded end connections on devices
SS.5 Flanged ends on devices
SS.6 Devices intended for connection to pipe systems
SS.7 Performance requirements for joints
SS.7.1 General
SS.7.2 Hydrostatic pressure test for assembled joints
SS.7.3 Liquid infiltration test
SS.7.4 Leaktightness under pressure when subjected to bending
Cited references in this standard
Metallic flanges for waterworks purposes
Pipe threads where pressure-tight joints are made on the threads, Part 1: Dimensions, tolerances and designation
Welding and brazing — Filler metals, Part 1: Filler metal for brazing and braze welding
Plumbing and drainage, Part 0: Glossary of terms
Copper and copper alloys — Wrought rods, bars and sections
Content history
DR AS/NZS 2845.1:2021
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