AS 3500.4-1994

1 - AS 3500.4-1994 NATIONAL PLUMBING AND DRAINAGE CODE - HOT WATER SUPPLY SYSTEMS
4 - PREFACE
5 - CONTENTS
8 - FOREWORD
9 - SECTION 1 SCOPE AN D GENERAL
9 - 1.1 SCOPE
9 - 1.2 APPLICATION
9 - 1.2.1 General
9 - 1.2.2 New materials and methods
9 - 1.2.3 Unusual installations
9 - 1.3 REFERENCED DOCUMENTS
10 - 1.4 DEFINITIONS
10 - 1.5 CLASSIFICATION OF SOILS
10 - 1.6 CLASSIFICATION OF BUILDINGS
10 - 1.7 WATER QUALITY
10 - 1.8 EQUIVALENT PIPE SIZES
10 - 1.9 FIRE RESISTANCE LEVEL (FRL)
10 - 1.10 WATER TEMPERATURE
10 - 1.10.1 Storage temperature
10 - 1.10.2 Sanitary fixtures delivery temperature (see Figure 1.1)
12 - SECTION 2 MATERIALS AND PRODUCTS
12 - 2.1 SCOPE OF SECTION
12 - 2.2 PIPES AND FITTINGS
12 - 2.2.1 Copper pipes
12 - 2.2.2 Copper alloy pipes
12 - 2. 2.3 Copper alloy fittings
12 - 2.2.4 Galvanized steel
12 - 2.2.5 Polybutylene (PB)
12 - 2.2.6 Polyethylene (PE)
12 - 2.2.7 Cross-linked polyethylene (PE-X)
13 - 2.2.8 Polypropylene (PP-R)
13 - 2.2.9 Stainless steel
13 - 2.3 CISTERN (COLD WATER STORAGE TANK) MATERIALS
13 - 2.3.1 Copper
13 - 2.3.2 Galvanized steel
13 - 2.3.3 Stainless steel
13 - 2.3.4 Other materials
13 - 2.4 SAFE TRAY AND SAFE WASTES MATERIALS
13 - 2.4.1 Safe tray
13 - 2.4.2 Safe wastes
13 - 2.5 JOINTING PRODUCTS
13 - 2.5.1 Rubber rings
14 - 2.5.2 Rubber gaskets
14 - 2.5.3 Silver brazing alloy
14 - 2.5.4 Solders
14 - 2.5.5 Filler rods for stainless steel joints
14 - 2.6 BEDDING MATERIAL
14 - 2.7 BACKFILL MATERIAL
14 - 2.8 MISCELLANEOUS MATERIALS
14 - 2.8.1 Timber
14 - 2.8.2 Thermal insulation
14 - 2.8.3 External protective coatings
15 - SECTION 3 INSTALLATION OF COLD AND HOT WATER PIPEWORK AND CONTROLS
15 - 3.1 SCOPE OF SECTION
15 - 3.2 SAFETY PRECAUTIONS
15 - 3.2.1 Electrical earthing
15 - 3.2.2 Proximity to electrical cables and gas pipes
15 - 3.3 GENERAL REQUIREMENTS
15 - 3.3.1 Methods of jointing
16 - 3.3.2 Support and fixing above ground
18 - 3.3.3 Securing of pipes and fittings
18 - 3.3.4 Location of pipework
19 - 3.3.5 Pipes in corrosive or contaminated areas
19 - 3.3.6 Pipes in water-charged or filled ground
19 - 3.3.7 Cross-connection control and backflow prevention
19 - 3.3.8 Depth of cover
19 - 3.4 PROTECTION AGAINST FREEZING
19 - 3.4.1 Requirement for protection
19 - 3.4.2 Piping located outside buildings
19 - 3.4.3 Pipes located on metal roofs
19 - 3.4.4 Pipes located inside buildings
20 - 3.4.5 Insulation of pipework
20 - 3.5 COLD WATER CONTROLS AND PIPING
20 - 3.5.1 General
21 - 3.5.2 Cold water cisterns
23 - 3.5.3 Safe tray for cold water cistern
23 - 3.5.4 Support for separately mounted cisterns
23 - 3.5.5 Support for externally mounted cisterns
23 - 3.6 INSTALLATION OF HOT WATER SUPPLY
23 - 3.6.1 Layout and size
24 - 3.6.2 Identification
24 - 3.6.3 Provision for expansion
26 - 3.6.4 Gradient
26 - 3.6.5 Maximum rise of hot water supply pipes
26 - 3.6.6 Shower assemblies
26 - 3.6.7 Venting of secondary circuit
26 - 3.6.8 Terminal fittings
26 - 3.7 THERMOSTATIC MIXING VALVES
27 - 3.7.1 Installation instructions
28 - 3.7.2 Commissioning instructions
28 - 3.7.3 Guidelines for maintenance instructions
28 - 3.8 TEMPERATURE CONTROL DEVICES
29 - SECTION 4 INSTALLATION OF WATER HEATERS OTHER THAN SOLAR HEATERS
29 - 4.1 SCOPE OF SECTION
29 - 4.2 WATER HEATERS
29 - 4.2.1 Water heaters
29 - 4.2.2 Selection of anode
29 - 4.2.3 Working pressure
29 - 4.2.4 Auxiliary controls
29 - 4.3 LOCATION
29 - 4.3.1 Placement
29 - 4.3.2 Minimum head
29 - 4.3.3 Accessibility and clearances
29 - 4.3.4 Ventilation and fluing
29 - 4.4 PROTECTION AGAINST DAMAGE FROM LEAKING WATER
29 - 4.4.1 Concealed water containers
30 - 4.4.2 Unconcealed storage water containers
30 - 4.4.3 Safe tray construction
30 - 4.4.4 Safe wastes
30 - 4.4.5 Placement of water heater or cistern on a safe tray
30 - 4.5 SUPPORT
30 - 4.5.1 Support of water containers installed in a roof
31 - 4.5.2 Support of water containers installed above a roof
31 - 4.5.3 Support of water containers installed other than in a roof space or above a roof
31 - 4.6 CORROSION PREVENTION AND WEATHER PROTECTION
31 - 4.6.1 Water heater base-corrosion avoidance
32 - 4.6.2 Weather protection of externally installed water heaters
32 - 4.7 CONNECTIONS TO WATER HEATERS
32 - 4.8 PRESSURE RELIEF AND VENTING OF WATER HEATERS AND CONTAINERS
32 - 4.9 VALVES
32 - 4.9.1 General
32 - 4.9.2 Required set pressure of valves (for unvented water heaters)
38 - 4.9.3 Installation of valves
39 - 4.10 MULTIPLE INSTALLATIONS OF PRESSURE-TYPE STORAGE WATER HEATERS
39 - 4.10.1 General
39 - 4.10.2 Balanced flow conditions
40 - 4.10.3 Positioning and sizing of pressure control valves
40 - 4.11 MULTIPLE INSTANTANEOUS WATER HEATERS
40 - 4.12 RELIEF AND EXPANSION VALVE DRAIN LINES
40 - 4.12.1 Size and material
40 - 4.12.2 Interconnection of drain lines
41 - 4.12.3 Installation
41 - 4.12.4 Common stack discharge
42 - 4.12.5 Tundish drain lines
42 - 4.12. 6 Areas subject to freezing
42 - 4.13 VENT PIPES
42 - 4.13.1 Installation
42 - 4.13.2 Termination of vent pipe
42 - 4.13.3 Cistern-fed water heaters (other than side-fed types)
42 - 4.13.4 Vented storage water heaters, inlet pressure-controlled
52 - SECTION 5 SOL AR HOT WATER SYSTEMS
52 - 5.1 SCOPE OF SECTION
52 - 5.2 GENERAL
52 - 5.2.1 Solar hot water systems
52 - 5.2.2 Location
52 - 5.3 INSTALLATION OF SOLAR HOT WATER SYSTEM CONTAINER
52 - 5.3.1 Solar hot water system containers
52 - 5.3.2 Containers installed on or above a roof
53 - 5.3.3 Protection against damage from leaking water
53 - 5.3.4 Connections to containers
53 - 5.3.5 Pressure relief and venting of containers
53 - 5.3.6 Valves
53 - 5.3.7 Relief and expansion valve drain lines
53 - 5.3.8 Vent pipes
53 - 5.4 INSTALLATION OF COLLECTORS
53 - 5.4.1 Positioning
54 - 5.4.2 Provision for removal of collector
54 - 5.4.3 Mountings
54 - 5.4.4 Precautions
57 - 5.5 INSTALLATION OF CLOSE-COUPLED AND INTEGRAL SOLAR HOT WATER SYSTEMS
57 - 5.5.1 General
57 - 5.5.2 Roof mountings and supports
57 - 5.5.3 Supplementary heating connections
58 - 5.6 THERMOSIPHON FLOW SOLAR HOT WATER SYSTEMS WITH REMOTE CONTAINERS
58 - 5.6.1 General
58 - 5.6.2 Supplementary heating connections
58 - 5.6.3 Primary circuit flow and return pipes
58 - 5.7 SOLAR HOT WATER SYSTEMS WITH FORCED PRIMARY CIRCULATION
58 - 5.7.1 General
58 - 5.7.2 Primary circulation pump
59 - 5.7.3 Pump installation
59 - 5.7.4 Primary circuit flow and return pipes
59 - 5.7.5 Supplementary external heating
59 - 5.8 SOLAR WATER HEATERS USED AS PREHEATERS
59 - 5.8.1 General
59 - 5.8.2 Installation of solar preheaters-cistern-fed water heaters
59 - 5.8.3 Installation of solar preheaters-mains pressure and reduced-pressure water heaters
60 - 5.8.4 Suitable types of existing heaters
60 - 5.9 MULTIPLE SOLAR HOT WATER SYSTEMS INSTALLATIONS
60 - 5.9.1 General
60 - 5.9.2 Thermosiphon systems-series connection
60 - 5.9.3 Thermosiphon systems-parallel connection of more than five units
60 - 5.9.4 Pumped systems-series and series-parallel connection
60 - 5.9.5 Pumped systems-parallel connection
61 - 5.10 SUPPLEMENTARY HEATING
61 - 5.10.1 Thermal capacity
61 - 5.10.2 Thermostat setting
61 - 5.10.3 Drain connection
61 - 5.10.4 Heating tube
61 - 5.10.5 Heating by instantaneous water heater
61 - 5.11 UNCONTROLLED SUPPLEMENTARY HEATERS
61 - 5.12 INSTALLATION OF SOLAR/ ELECTRIC WATER HEATING SYSTEMS
61 - 5.12.1 Circuit
61 - 5.12.2 Isolation switch label
61 - 5.13 INSTALLATION OF SOLAR/GAS WATER HEATING SYSTEMS
61 - 5.14 INSTALLATION OF SOLAR/SOLID FUEL WATER HEATING SYSTEMS (INCLUDING SLOW COMBUSTION COOKERS FITTED WITH WATER-HEATING...
61 - 5.15 INSTALLATION OF SOLAR/OIL- FIRED WATER HEATING SYSTEMS
72 - SECTION 6 ENERG Y SOURCES AND HEAT RETENTION
72 - 6.1 CONTROLLED ENERGY SOURCES
72 - 6.1.1 Scope of Section
72 - 6.1.2 Electric supply
72 - 6.1.3 Gas-fired water heaters
72 - 6.1.4 Oil-fired water heaters
72 - 6.2 WATER HEATERS WITH UNCONTROLLED ENERGY SOURCE
72 - 6.2.1 Installation
73 - 6.2.2 Supplementary external heating
73 - 6.2.3 Provision for drainage
73 - 6.3 HEAT RETENTION
73 - 6.3.1 General
73 - 6.3.2 Lagging to be provided
73 - 6.3.3 Lagging exposed to the weather
73 - 6.3.4 Lagging of buried piping
73 - 6.3.5 Lagging of encased piping
73 - 6.3.6 Piping to be lagged
75 - SECTION 7 HOT WATER SERVICES FOR THE DISABLED
75 - 7.1 SCOPE OF SECTION
75 - 7.2 GENERAL
75 - 7.3 BASINS
75 - 7.4 SHOWERS
76 - SECTI ON 8 TESTING AND COMMISSIONING
76 - 8.1 SCOPE OF SECTION
76 - 8.2 FLUSHING
76 - 8.3 TESTING
76 - 8.4 COMMISSIONING
76 - 8.5 OPERATING INSTRUCTIONS
77 - SECTION 9 OPERATION AND MAINTENANCE
77 - 9.1 SCOPE OF SECTION
77 - 9.2 GENERAL
77 - 9.3 MAINTENANCE OF HOT WATER SERVICES
78 - APPENDIX A - REFERENCED DOCUMENTS-MATERIALS AND PRODUCTS
79 - APPENDIX B - REFERENCED DOCUMENTS-INSTALLATION
79 - APPENDIX C - REFERENCED DOCUMENTS-MISCELLANEOUS
80 - APPENDIX D - WATER ANALYSIS
80 - D1 WATER ANALYSIS
80 - D2 TOTAL DISSOLVED SOLIDS (TDS)
80 - D3 SCALING PROPERTIES
80 - D4 WATER pH
80 - APPENDIX E - TYPICAL RATES OF FLOW
81 - APPENDIX F - PREFERRED SIZES OF PIPE FOR NON-CIRCULATORY AVERAGE SINGLE-STOREY TYPE HOUSEHOLD INSTALLATIONS...
82 - APPENDIX G - RECOMMENDATIONS FOR THE INSTALLATION OF UNRATED SOLAR HOT WATER SUPPLY SYSTEMS
82 - G1 GENERAL
82 - G2 VOLUMETRIC STORAGE CAPACITY
82 - G3 RECOMMENDED OPERATING TEMPERATURE
82 - G4 COMBINED TEMPERATURE/PRESSURE RELIEF VALVE
82 - G5 COLLECTOR/CONTAINER SIZE RATIO
82 - G5.1 Normal conditions
82 - G5.2 Non-optimum conditions
83 - APPENDIX H - RECOMMENDATIONS FOR THE INSTALLATION OF CLOSE- COUPLED AND INTEGRAL SOLAR HOT WATER SYSTEMS ON ROOFS
83 - H1 GENERAL
83 - H2 SUPPORT
83 - H2.1 ‘With pitch’ installations
83 - H2.2 ‘Against pitch’ installations
83 - H2.3 ‘Cross pitch’ installations
83 - H3 POINTS TO NOTE
86 - APPENDIX I - ESTIMATION OF SHADING OF COLLECTORS
86 - I1 GENERAL
86 - I2 SUN LOCATOR
87 - I3 APPROXIMATE METHOD OF DETERMINING SOLAR ALTITUDE
90 - APPENDIX J - EFFECT OF INCLINATION AND ORIENTATION ON SYSTEM PERFORMANCE
95 - APPENDIX K - MAP OF REGIONAL BASIC DESIGN WIND SPEEDS
96 - APPENDIX L - SOLAR HOT WATER SYSTEMS SUGGESTED COMPONENT SIZES (UNRATED SYSTEMS)
96 - L1 GENERAL
96 - L2 ANTICIPATED SOLAR FRACTION
96 - L3 SOLAR RADIATION DATA

Specifies uniform requirements for the installation of water heaters and hot water reticulation. Account has been taken of the current regulations of the water, gas and electricity supply authorities and local government bodies in each State and Territory of Australia.

This Standard sets out the requirements for the installation of piping and apparatus for single and multiple domestic-type water heaters, from and including the isolating valve on the cold water inlet and the reticulation of hot water. This Standard applies to the installation of the following types of water heaters which comply with Clause 4.2.1 or Clause 5.3.1:(a) Electric storage water heaters with a rated delivery of up to 630 L per heater.(b) Other types of storage water heaters with a capacity of up to 700 L per heater.(c) Solar water heaters with a capacity of up to 700 L per heater.(d) Heat exchange water heaters in accordance with AS 1361.(e) Instantaneous water heaters.(f) Other water heaters authorized by the relevant regulatory authority.NOTE: The reference to AS 1361 in Item (d) is made to positively identify the particular type of heat exchange water heater to which this Standard applies.This Standard applies to hot water systems using potable water only and does not apply to space heating or swimming pool heating.Illustrations used in this Standard are diagrammatic only and have been chosen without prejudice.1.2

AS 3500.4 first published in part as AS CA51-1968.
Revised and redesignated AS 1529-1974.
AS 2002 first published 1979.
Second edition 1981.
Third edition 1987.
AS 1529-1974 and AS 2002-1978 revised, amalgamated and redesignated AS 3500.4-1990.
Second edition 1994.
Incorporating: Amdt 1-1996