AS 4426-1997 (R2018)

1 - AS 4426-1997 THERMAL INSULATION OF PIPEWORK, DUCTWORK AND EQUIPMENT - SELECTION, INSTALLATION AND FINISH
4 - PREFACE
5 - CONTENTS
7 - SECTION 1 SCOPE AND GENERAL
7 - 1.1 GENERAL
7 - 1.1.1 Scope
7 - 1.1.2 New designs and innovations
7 - 1.2 REFERENCED DOCUMENTS
7 - 1.3 DEFINITIONS
8 - 1.3.1 Castable cement insulating material
8 - 1.3.2 Coating
8 - 1.3.3 Finishing materials
8 - 1.3.4 Flexible insulating material
8 - 1.3.5 Gypsum plaster
8 - 1.3.6 Hard-setting composition
8 - 1.3.7 Mastic
8 - 1.3.8 Metal cladding, sheathing
8 - 1.3.9 Mineral fibre
8 - 1.3.10 Plastic insulating and finishing materials
8 - 1.3.11 Preformed insulating material
8 - 1.3.12 Self-setting cement
8 - 1.4 EXCHANGE OF DESIGN DATA
8 - 1.4.1 Information to be supplied by the purchaser
8 - 1.4.2 Preparation of surfaces
8 - 1.4.3 Plant details
9 - 1.4.4 Types of fittings and supports
9 - 1.4.5 Type of insulation
9 - 1.4.6 Type of finish
9 - 1.4.7 Special service requirements
9 - 1.4.8 Basis on which the thickness of insulation is to be determined
9 - 1.4.9 Information to be supplied by the manufacturer or contractor
9 - 1.4.10 Drawings
10 - 1.5 PRACTICAL DESIGN CONSIDERATIONS
10 - 1.5.1 General
10 - 1.5.2 Clearance between insulation and the surrounding surfaces
10 - 1.5.3 Provision for differential thermal movement
11 - 1.5.4 Insulation support
14 - 1.5.5 Insulation of pipes in ducts and subways
14 - 1.5.6 Insulation for airconditioning ductwork
14 - 1.5.7 Fire hazards
16 - 1.6 TEMPERATURE CLASSIFICATIONS
16 - 1.7 CONTRACTS
17 - SECTION 2 SELECTION OF INSULATING MATERIALS AND SYSTEMS
17 - 2.1 CHARACTERISTICS OF INSULATING MATERIALS
17 - 2.1.1 Thermal conductivity and thermal resistance
17 - 2.1.2 Physical forms
23 - 2.1.3 Bulk density
23 - 2.1.4 Suitability for service temperature
25 - 2.1.5 Thermal expansion
25 - 2.1.6 Resistance to compaction
25 - 2.1.7 Resistance to vapour penetration and absorption
25 - 2.1.8 Mechanical strength and durability
26 - 2.1.9 Fire and explosion hazards
26 - 2.1.10 Resistance to vermin and fungus
27 - 2.1.11 Health hazards
28 - 2.1.12 Optimum heat capacity
28 - 2.1.13 Freedom from objectionable odour
28 - 2.1.14 Chemical resistance
28 - 2.2 SELECTION OF THERMAL INSULATING SYSTEMS
28 - 2.2.1 Optimum effectiveness
28 - 2.2.2 Extent of system
29 - 2.2.3 General
29 - 2.2.4 Facts for consideration
31 - SECTION 3 SELECTION OF SECURING MATERIALS
31 - 3.1 GENERAL
31 - 3.2 ADHESIVES
31 - 3.2.1 General
31 - 3.2.2 Classification according to use
32 - 3.2.3 Application characteristics
32 - 3.2.4 Temperature limits
32 - 3.2.5 Adhesive strength
32 - 3.3 MECHANISM OF CURING
32 - 3.3.1 Solvent-based adhesives
33 - 3.3.2 Chemically curing adhesives
33 - 3.3.3 Hot melt adhesives
33 - 3.4 MECHANICAL SECUREMENTS
33 - 3.4.1 General
34 - 3.4.2 Welded attachments
34 - 3.4.3 Bolted fittings
34 - 3.4.4 Banding and wire securements
34 - 3.5 COMBINATION
35 - SECTION 4 VAPOUR BARRIERS
35 - 4.1 GENERAL
35 - 4.2 CONDENSATION AND FREEZING
35 - 4.3 REQUIREMENTS FOR A VAPOUR BARRIER
35 - 4.4 VAPOUR BARRIERS FOR USE OVER INSULATION ON SURFACES ABOVE DEW POINT
35 - 4.5 FACTORS WHICH MUST BE CONSIDERED
36 - 4.6 MATERIALS
37 - SECTION 5 SELECTION AND TREATMENT OF FINISHING MATERIALS
37 - 5.1 GENERAL
37 - 5.2 FINISHING MATERIALS
37 - 5.3 REASONS FOR USE
38 - 5.4 TYPICAL CHARACTERISTICS OF AND USES FOR FINISHING MATERIALS
38 - 5.4.1 General
38 - 5.4.2 Group (a)
38 - 5.4.3 Group (b)
38 - 5.4.4 Group (c)
39 - 5.4.5 Group (d)
39 - 5.5 FINISHES FOR TROPICAL CONDITIONS
39 - 5.5.1 General
39 - 5.5.2 Interior plant in tropical climates
39 - 5.5.3 Outdoor plant in tropical climates
40 - 5.6 FINISHES FOR REFRIGERATION WORK
40 - 5.7 FINISHES TO IMPROVE FIRE PROTECTIVE PROPERTIES
40 - 5.8 FINISHES FOR USE OVER PIPES IN DUCTS AND SUBWAYS, OR BENEATH BUILDINGS
40 - 5.9 ULTIMATE TREATMENT OF FINISH
40 - 5.9.1 General
40 - 5.9.2 Painting as a final finish
41 - 5.9.3 Indoor applications
41 - 5.9.4 Outdoor applications
42 - SECTION 6 METHODS OF APPLICATION
42 - 6.1 GENERAL
42 - 6.2 SURFACE PREPARATION AND ATTACHMENTS
42 - 6.2.1 Surface preparation
42 - 6.2.2 Attachments
45 - 6.3 INSULATION SUPPORTS
45 - 6.3.1 General
45 - 6.3.2 Stud-type supports
48 - 6.3.3 Cross-sectional area of supports
48 - 6.3.4 Support penetration and thermal bridging
48 - 6.3.5 Finishing material support
48 - 6.3.6 Securement (tie wires, lacing wire, bands, clips, washers and nuts)
49 - 6.3.7 Reinforcement
50 - 6.4 COLD INSULATION: APPLICATION FOR SYSTEMS OPERATING IN THE TEMPERATURE RANGE -75°C TO +10°C
50 - 6.4.1 General
51 - 6.4.2 Adhesives and fastenings
51 - 6.4.3 Typical erection methods
52 - 6.4.4 Pipework and fittings
53 - 6.4.5 Vessels and large curved surfaces
53 - 6.4.6 Airconditioning ductwork (temperature range up to 10°C)
58 - 6.4.7 Flat and irregular surfaces (including machinery)
58 - 6.5 HOT INSULATION: APPLICATION FOR SYSTEMS OPERATING IN THE TEMPERATURE RANGE +10°C TO 800°C
58 - 6.5.1 General
58 - 6.5.2 Pipework
66 - 6.5.3 Flexible materials
67 - 6.5.4 Foamed-in-situ
67 - 6.5.5 Sprayed insulation
67 - 6.5.6 Loosefill insulation
67 - 6.5.7 Insulating concrete
67 - 6.5.8 Pipes with auxiliary heating
68 - 6.5.9 Piping bends
69 - 6.5.10 Flanges, valves and other fittings on hot piping
70 - 6.5.11 Vessels and large curved surfaces
78 - 6.5.12 Airconditioning ducts
79 - 6.5.13 Hot-air ducts (industrial applications) indoor and outdoor
80 - 6.5.14 Gas flues (indoor service)
82 - 6.5.15 Gas flues (outdoor service)
84 - 6.5.16 Flat and irregular surfaces (including machinery)
87 - SECTION 7 FINISHES-METHODS OF APPLICATION
87 - 7.1 INDOOR FINISHES
87 - 7.1.1 Hard-setting composition or self-setting cement
88 - 7.2 TEXTILE FABRICS
88 - 7.2.1 Woven scrim fabric
88 - 7.2.2 Lightweight canvas and bands
88 - 7.2.3 Heavy fabric wrappings
88 - 7.3 PLASTIC SHEET AND ELASTOMER SHEET
88 - 7.3.1 General
88 - 7.3.2 Rigid sheet
89 - 7.3.3 Flexible sheet
89 - 7.3.4 Removable insulations
89 - 7.3.5 Colour
89 - 7.3.6 Tape
89 - 7.3.7 Preformed materials
89 - 7.4 MASTIC AND COATING FINISHES
89 - 7.4.1 General
90 - 7.4.2 Water-based materials
90 - 7.4.3 Solvent- based materials
90 - 7.4.4 Solvent-free materials
90 - 7.5 METAL SHEET
90 - 7.5.1 General
90 - 7.5.2 Mild steel
90 - 7.5.3 Alloy steel
90 - 7.5.4 Aluminium
91 - 7.5.5 Compatibility
92 - 7.5.6 Sheet thickness
92 - 7.5.7 Application
92 - 7.5.8 Securement
92 - 7.5.9 Vertical pipework
92 - 7.5.10 Flat surfaces
92 - 7.5.11 Surface temperatures
92 - 7.5.12 Board finishes
93 - 7.6 WEATHER RESISTANT FINISHES
93 - 7.6.1 Metal sheet
96 - 7.6.2 Weatherproofing compounds
100 - 7.6.3 Self-setting cement
100 - 7.6.4 Plastic and elastomer sheet
100 - 7.6.5 Roofing felt and wire netting
100 - 7.7 ULTIMATE TREATMENT OF FINISH PAINTING
101 - APPENDIX A - INSPECTION, TESTING AND MAINTENANCE
101 - A1 INSPECTION AND TESTING
101 - A2 SITE MAINTENANCE RECOMMENDATIONS
102 - APPENDIX B - PROTECTION AGAINST CORROSION
102 - B1 ELECTROLYTIC CORROSION
102 - B2 CORROSION, STRESS-CORROSION CRACKING AND LIQUID METAL ATTACK
102 - B2.1 General
102 - B2.2 Oxidation
103 - B2.3 Acidic corrosion
104 - B2.4 Alkaline corrosive attack
104 - B2.5 Intergranular corrosion
104 - B2.6 Bimetallic (galvanic) corrosion
104 - B3 STRESS-CORROSION CRACKING
104 - B3.1 Action of water-soluble chlorides on austenitic alloy steels
105 - B3.2 Stress-corrosion attack on other metals
105 - B4 ATTACK BY LIQUID METALS
107 - APPENDIX C - PROTECTION AGAINST CONDENSATION
107 - C1 PROTECTION AGAINST CONDENSATION
107 - C1.1 General
107 - C1.2 Site considerations
107 - C1.3 Sealing
107 - C2 CASE DESCRIPTIONS
107 - C2.1 Sugar mill boiler
107 - C2.2 Bread-baking oven
108 - C2.3 Fire-rated bulkhead
108 - C2.4 Oxygen plant
108 - C3 VAPOUR BARRIERS
108 - C3.1 General
108 - C3.2 Inherent vapour resistance
108 - C3.3 Barrier performance
112 - C3.4 Protection from damage
112 - C3.5 Compatibility
112 - C3.6 Breather materials
112 - C3.7 Fire resistance
112 - C3.8 Application
112 - C3.9 Below dewpoint operation
113 - C3.10 Cyclic operation
114 - APPENDIX D - STANDARDS FOR INSULATING MATERIALS

Deals with the selection, installation and finish of thermal insulation for pipework, ductwork, tanks, vessels, and equipment in the temperature range -75C to +800C, but excludes manufactured pre-insulated equipment, structural insulation of buildings and cold stores, fireproofing structures, refractory linings of plant, airborne installations and all external underground mains.
RECONFIRMATION NOTICE
Major stakeholders of this publication have reviewed the content of this publication and in accordance with Standards Australia procedures for reconfirmation, it has been determined that the publication is still valid and does not require change.
Certain documents referenced in the publication may have been amended since the original date of publication. Users are advised to ensure that they are using the latest versions of such documents as appropriate, unless advised otherwise in this Reconfirmation Notice.
Approved for reconfirmation in accordance with Standards Australia procedures for reconfirmation on 29 August 2018.

This Standard deals with the selection, installation and finish of thermal insulation for pipework, ductwork, tanks, vessels and equipment in the temperature range -75C to +800C but excludes manufactured pre-insulated equipment, structural insulation of buildings and cold stores, fireproofing structures, refractory linings of plant, airborne installations and all external underground mains.NOTES:1 The Standard may be found to be generally applicable to the insulation of road and rail transport vehicles and of some assistance in marine insulation.2 Appendices to the Standard provide guidance on inspection, testing and maintenance (Appendix A), protection against condensation (Appendix B), protection against corrosion (Appendix C) and relevant Australian Standards on insulation materials (Appendix D).

First published as AS 4426-1997.
Reconfirmed 2018.