Standard
UPDATE AVAILABLE

AS/NZS 3500.4.2:1997

[Superseded]

National Plumbing and Drainage, Part 4.2: Hot water supply systems — Acceptable solutions

Specifies the requirements for the installation of domestic type water heaters using potable water. It includes aspects of the installation from, and including, the valves on the cold water inlet to any cistern or water heater and the downstream fixtures and fittings. The Standard applies to new installations as well as alterations, additions and repairs to existing installations.
Published: 05/10/1997
Pages: 100
Table of contents
Cited references
Content history
Table of contents
Header
About this publication
PREFACE
FOREWORD
1 SCOPE AND GENERAL
1.1 SCOPE AND APPLICATION
1.2 REFERENCED DOCUMENTS
1.3 DEFINITIONS
1.4 WATER QUALITY
1.5 EQUIVALENT PIPE SIZES
1.6 WATER TEMPERATURE
1.6.1 Storage temperature
1.6.2 Sanitary fixtures delivery temperature
2 MATERIALS AND PRODUCTS
2.1 SCOPE OF SECTION
2.2 AUTHORIZATION
2.3 LIMITS ON USE OF PIPES AND FITTINGS
2.3.1 Copper pipes
2.3.2 Copper alloy pipes
2.3.3 Copper alloy fittings
2.3.4 Galvanized steel
2.3.5 Polybutylene (PB)
2.3.6 Polyethylene (PE)
2.3.7 Cross-linked polyethylene (PE-X)
2.3.8 Polypropylene (PP-R)
2.3.9 Chlorinated polyvinyl chloride (CPVC)
2.3.10 Stainless steel
2.4 CISTERN (COLD WATER STORAGE TANK) MATERIALS
2.4.1 Copper
2.4.2 Galvanized steel
2.4.3 Stainless steel
2.4.4 Other materials
2.5 SAFE TRAY AND SAFE WASTE MATERIALS
2.5.1 Safe tray
2.5.2 Safe wastes
2.6 JOINTING
2.6.1 Elastomeric rings
2.6.2 Elastomeric gaskets
2.6.3 Silver brazing alloy
2.6.3.1 Copper and copper alloys
2.6.3.2 Stainless steels
2.6.4 Soft solders
2.6.5 Filler rods for stainless steel joints
2.7 BEDDING AND BACKFILL
2.8 MISCELLANEOUS MATERIALS
2.8.1 Timber
2.8.2 Thermal insulation
2.8.3 External protective coatings
3 INSTALLATION OF COLD AND HOT WATER PIPING AND CONTROLS
3.1 SCOPE OF SECTION
3.2 SAFETY PRECAUTIONS
3.2.1 Electrical earthing
3.2.2 Proximity to electrical cables and gaspipes
3.3 METHODS OF JOINTING
3.3.1 General
3.3.2 Prohibited methods
3.3.3 Threading
3.3.4 Compression-type fittings
3.3.5 Flanged joints
3.3.6 Jointing of stainless steel pipe and fittings
3.3.6.1 Jointing of pipework, up to and including DN 25
3.3.6.2 Jointing of pipework larger than DN 25
3.3.7 Alternative jointing
3.4 SUPPORT AND FIXING ABOVE GROUND
3.4.1 General
3.4.2 Brackets, clips and hangers
3.4.3 Prohibited supports
3.4.4 Spacing
3.4.5 Securing of pipes and fittings
3.5 LOCATION OF PIPING
3.5.1 Walls
3.5.2 Chases, ducts or conduits
3.5.3 Under concrete slabs
3.5.4 Protection during building construction
3.5.5 Floor or roof penetrations
3.5.6 Protection of buried piping
3.5.7 Protection of encased piping
3.6 PIPES IN WATER-CHARGED OR FILLED GROUND
3.7 CROSS-CONNECTION CONTROL AND BACKFLOW PREVENTION
3.8 CONTAMINATED AREAS
3.8.1 General
3.8.2 Installation
3.9 CORROSIVE AREAS
3.10 DEPTH OF COVER IN PUBLIC AREAS
3.11 DEPTH OF COVER IN PRIVATE AREAS
3.12 PROTECTION AGAINST FREEZING
3.12.1 Requirement for protection
3.12.2 Piping located outside buildings
3.12.3 Pipes located on metal roofs
3.12.4 Pipes located inside buildings
3.12.4.1 General
3.12.4.2 Pipes in unheated roof spaces
3.12.4.3 Pipes adjacent to external walls
3.12.5 Insulation of piping
3.13 COLD WATER PIPING AND CISTERNS
3.13.1 General
3.13.2 Cold water cisterns (See Figures 4.1 and 4.2)
3.13.2.1 General
3.13.2.2 Cistern capacity
3.13.2.3 Flow capacity
3.13.2.4 Cistern overflow
3.13.2.5 Position of cistern
3.13.3 Safe tray for cold water cistern
3.13.4 Support for separately mounted cisterns
3.13.4.1 Platform
3.13.4.2 Spacing between cold water cistern and safe tray
3.14 INSTALLATION OF HOT WATER SUPPLY
3.14.1 Layout and size
3.14.2 Identification
3.14.3 Provision for expansion
3.14.3.1 General
3.14.3.2 Expansion of fixed offsets
3.14.3.3 U-bends, coiled loops, offsets and lyre bends
3.14.3.4 Placement of bends and offsets
3.14.4 Gradient
3.14.5 Maximum rise of hot water supply pipes
3.14.6 Shower assemblies
3.14.7 Venting of secondary circuit
3.14.8 Terminal fittings
3.15 TEMPERATURE CONTROL DEVICES
3.16 THERMOSTATIC MIXING VALVES
4 INSTALLATION OF WATER HEATERS—GENERAL REQUIREMENTS
4.1 SCOPE OF SECTION
4.2 WATER HEATERS
4.2.1 Water heaters
4.2.2 Selection of anode
4.2.3 Working pressure
4.2.4 Auxiliary controls
4.3 LOCATION
4.3.1 Placement
4.3.2 Accessibility and clearances
4.3.3 Ventilation and fluing
4.4 PROTECTION AGAINST DAMAGE FROM LEAKING WATER
4.4.1 Concealed water containers
4.4.2 Unconcealed storage water containers
4.4.3 Safe tray construction
4.4.4 Safe wastes
4.4.4.1 Sizes of safe wastes
4.4.4.2 Safe waste construction
4.4.4.3 Safe waste installation
4.4.5 Placement of water heater or cistern on a safe tray
4.5 SUPPORT
4.5.1 Support of water containers installed in a roof
4.5.2 Support of water containers installed above a roof
4.5.3 Support of water containers installed other than in a roof space or above a roof
4.5.4 Seismic restraints
4.6 CORROSION PREVENTION AND WEATHER PROTECTION
4.6.1 Water heater base—corrosion avoidance
4.6.2 Weather protection of externally installed water heaters
4.7 CONNECTIONS TO WATER HEATERS
4.8 PRESSURE RELIEF AND VENTING OF WATER HEATERS AND CONTAINERS
4.9 VALVES
4.9.1 General
4.9.2 Required set pressure of valves (for unvented water heaters)
4.9.3 Installation of valves
4.10 MULTIPLE INSTALLATIONS OF PRESSURE-TYPE STORAGE WATER HEATERS
4.10.1 General
4.10.2 Balanced flow conditions
4.10.3 Positioning and sizing of pressure control valves
4.11 MULTIPLE INSTANTANEOUS WATER HEATERS
4.12 TEMPERATURE/PRESSURE/RELIEF AND EXPANSION CONTROL VALVE DRAIN LINES
4.12.1 Size and material
4.12.2 Interconnection of drain lines
4.12.2.1 Individual water heaters
4.12.2.2 Multiple relief valves
4.12.3 Installation
4.12.4 Common stack discharge
4.12.5 Tundish drain lines
4.12.6 Areas subject to freezing
4.13 VENT PIPES
4.13.1 Installation
4.13.2 Termination of vent pipe
4.13.3 Cistern-fed water heaters (other than side-fed types)
4.13.4 Vented storage water heaters, inlet pressure-controlled
5 INSTALLATION OF SOLAR WATER HEATERS
5.1 SCOPE OF SECTION
5.2 GENERAL
5.2.1 Performance
5.2.2 Solar water heater
5.2.3 Location
5.2.4 Sizing
5.3 INSTALLATION OF SOLAR WATER HEATER CONTAINER
5.3.1 Solar water heater containers
5.3.2 Containers installed on or above a roof
5.3.2.1 Support
5.3.2.2 Protection of externally mounted containers
5.3.3 Containers installed in a roof
5.3.4 Protection against damage from leaking water
5.3.5 Connection to containers
5.3.6 Pressure relief and venting of containers
5.3.7 Valves
5.3.8 Relief and expansion valve drain lines
5.3.9 Vent pipes
5.3.10 Supplementary heating connections
5.4 INSTALLATION OF COLLECTORS
5.4.1 Positioning
5.4.1.1 Shade
5.4.1.2 Relative to container
5.4.1.3 Orientation
5.4.1.4 Inclination
5.4.2 Provision for removal of collector
5.4.3 Mountings
5.4.3.1 Manufacturer’s instructions
5.4.3.2 Method of mounting
5.4.4 Precautions
5.4.4.1 Frost-prone areas
5.4.4.2 Water salinity
5.4.4.3 Water hardness
5.4.4.4 Cyclonic areas
5.4.4.5 Hail-prone areas
5.5 INSTALLATION OF CLOSE-COUPLED AND INTEGRAL SOLAR WATER HEATERS
5.5.1 General
5.5.2 Roof mountings and supports
5.6 THERMOSIPHON FLOW SOLAR WATER HEATERS WITH REMOTE CONTAINERS
5.6.1 General
5.6.2 Primary circuit flow and return pipes—Pipes and fittings
5.7 SOLAR WATER HEATERS WITH FORCED PRIMARY CIRCULATION
5.7.1 General
5.7.2 Primary circulation pump
5.7.2.1 Construction
5.7.2.2 Capacity
5.7.3 Pump and controller installation
5.8 SOLAR WATER HEATERS USED AS PREHEATERS
5.8.1 General
5.8.2 Installation of solar preheaters—cistern-fed water heaters
5.8.3 Installation of solar preheaters—mains pressure and reduced-pressure water heaters
5.8.3.1 New buildings installation
5.8.3.2 Existing systems installation
5.8.4 Suitable types of existing heaters
5.9 MULTIPLE SOLAR WATER HEATERS INSTALLATIONS
5.9.1 General
5.9.2 Thermosiphon systems—series connection
5.10 SUPPLEMENTARY HEATING
5.10.1 Thermal capacity
5.10.2 Drain connection
6 ENERGY SOURCES AND HEAT RETENTION
6.1 SCOPE OF SECTION
6.2 CONTROLLED ENERGY SOURCES
6.2.1 Electric supply
6.2.2 Gas-fired water heater installations
6.2.3 Oil-fired water heaters
6.3 WATER HEATERS WITH UNCONTROLLED ENERGY SOURCE
6.3.1 Installation
6.3.2 Supplementary external heating
6.3.3 Provision for drainage
6.4
6A ENERGY EFFICIENCY
6A.1 SCOPE OF SECTION
6A.2 INSULATION
6A2.1 General
6A.2.2 General piping to be insulated
6A.2.3 Hot water system piping
6A.2.4 Insulation exposed to the weather
6A.3 HEAT TRAPS
7 HOT WATER SERVICES FOR THE DISABLED
7.1 SCOPE OF SECTION
7.2 GENERAL
8 TESTING AND COMMISSIONING
8.1 SCOPE OF SECTION
8.2 FLUSHING
8.3 TESTING
8.4 COMMISSIONING
8.5 OPERATING INSTRUCTIONS
9 OPERATION AND MAINTENANCE
9.1 SCOPE OF SECTION
9.2 GENERAL
9.3 MAINTENANCE OF HOT WATER SERVICES
APPENDIX A
APPENDIX B
B1 WATER ANALYSIS
B2 TOTAL DISSOLVED SOLIDS (TDS)
B3 SCALING PROPERTIES
B4 WATER pH
APPENDIX C
APPENDIX D
APPENDIX E
E1 GENERAL
E2 VOLUMETRIC STORAGE CAPACITY
E3 RECOMMENDED OPERATING TEMPERATURE
E4 COMBINED TEMPERATURE/PRESSURE RELIEF VALVE
E5 COLLECTOR/CONTAINER SIZE RATIO
E5.1 Normal conditions
E5.2 Non-optimum conditions
APPENDIX F
F1 GENERAL
F2 SUPPORT
F2.1 ‘With pitch’ installations
F2.2 ‘Against pitch’ installations
F2.3 ‘Cross pitch’ installations
F3 POINTS TO NOTE
APPENDIX G
G1 GENERAL
G2 ANTICIPATED SOLAR FRACTION
G3 SOLAR RADIATION DATA
APPENDIX H
H1 GENERAL
H2 SUN LOCATER
H3 APPROXIMATE METHOD OF DETERMINING SOLAR ALTITUDE
APPENDIX I
APPENDIX J
APPENDIX K
K1 SCOPE
K2 CLIMATE REGIONS
APPENDIX L
L1 SCOPE
L2 CLIMATE REGIONS
Amendment control sheet
Cited references in this standard
[Withdrawn]
Amendment 1 to AS 3142-1986
[Available Superseded]
Minimum design loads on structures (known as the SAA Loading Code), Part 2: Wind loads
[Superseded]
Welding and brazing — Filler metals, Part 2: Filler metal for welding
[Available Superseded]
Welding and brazing — Filler metals, Part 1: Filler metal for brazing and braze welding
[Current]
Steel tubes and tubulars for ordinary service
Content history
[Available Superseded]
[Withdrawn]
[Withdrawn]
[Superseded]
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