AS 4426-1997

$242.18

Thermal insulation of pipework, ductwork and equipment — Selection, installation and finish

Deals with the selection, installation and finish of thermal insulation for pipework, ductwork, tanks, vessels, and equipment in the temperature range -75 degrees Celsius to +800 degrees Celsius, 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.

Table of contents
Header
About this publication
Preface
1 Scope and general
1.1 General
1.1.1 Scope
1.1.2 New designs and innovations
1.2 Referenced documents
1.3 Definitions
1.4 Exchange of design data
1.4.1 Information to be supplied by the purchaser
1.4.2 Preparation of surfaces
1.4.3 Plant details
1.4.4 Types of fittings and supports
1.4.5 Type of insulation
1.4.6 Type of finish
1.4.7 Special service requirements
1.4.8 Basis on which the thickness of insulation is to be determined
1.4.9 Information to be supplied by the manufacturer or contractor
1.4.10 Drawings
1.5 Practical design considerations
1.5.1 General
1.5.2 Clearance between insulation and the surrounding surfaces
1.5.3 Provision for differential thermal movement
1.5.3.1 Hot surfaces
1.5.3.2 Sliding and bellows expansion joints
1.5.3.3 Cold surfaces
1.5.4 Insulation support
1.5.5 Insulation of pipes in ducts and subways
1.5.6 Insulation for airconditioning ductwork
1.5.7 Fire hazards
1.5.7.1 Insulating materials
1.5.7.2 Ductwork systems
1.5.7.3 Finishing materials
1.5.7.4 Aluminium paint
1.5.7.5 Aluminium cladding
1.5.7.6 Galvanized sheet
1.5.7.7 Internal self-heating
1.5.7.8 Earthing
1.5.7.9 Secondary contamination
1.5.7.10 Storage
1.5.7.11 Protection
1.5.7.12 Maintenance
1.5.7.13 Fire retardants
1.6 Temperature Classifications
1.7 Contracts
2 Selection of insulating materials and systems
2.1 Characteristics of insulating materials
2.1.1 Thermal conductivity and thermal resistance
2.1.2 Physical forms
2.1.3 Bulk density
2.1.4 Suitability for service temperature
2.1.5 Thermal expansion
2.1.6 Resistance to compaction
2.1.7 Resistance to vapour penetration and absorption
2.1.8 Mechanical strength and durability
2.1.8.1 Mechanical strength
2.1.8.2 Durability
2.1.9 Fire and explosion hazards
2.1.10 Resistance to vermin and fungus
2.1.11 Health hazards
2.1.11.1 General
2.1.11.2 Removal
2.1.11.3 Asbestos disposal
2.1.11.4 Fibrous materials
2.1.11.5 Cements
2.1.11.6 Chemicals
2.1.11.7 Castable cement
2.1.11.8 Adhesives
2.1.11.9 Polymeric foam
2.1.12 Optimum heat capacity
2.1.13 Freedom from objectionable odour
2.1.14 Chemical resistance
2.2 Selection of thermal insulating systems
2.2.1 Optimum effectiveness
2.2.2 Extent of system
2.2.3 General
2.2.4 Facts for consideration
2.2.4.1 Temperature
2.2.4.2 Mechanical stability
2.2.4.3 Resistance to degradation
2.2.4.4 Thermal effectiveness
2.2.4.5 Quality control
2.2.4.6 Type and dimensions of the plant to be insulated
2.2.4.7 Compatibility of the components of the system
2.2.4.8 Total weight of the system
2.2.4.9 Corrosion hazards
3 Selection of securing materials
3.1 General
3.2 Adhesives
3.2.1 General
3.2.2 Classification according to use
3.2.3 Application characteristics
3.2.4 Temperature limits
3.2.5 Adhesive strength
3.3 Mechanism of curing
3.3.1 Solvent-based adhesives
3.3.2 Chemically curing adhesives
3.3.3 Hot melt adhesives
3.4 Mechanical Securements
3.4.1 General
3.4.2 Welded attachments
3.4.3 Bolted fittings
3.4.4 Banding and wire securements
3.5 Combination
4 Vapour barriers
4.1 General
4.2 Condensation and freezing
4.3 Requirements for a vapour barrier
4.4 Vapour barriers for use over insulation on surfaces above dew point
4.5 Factors which must be considered
4.6 Materials
5 Selection and treatment of finishing materials
5.1 General
5.2 Finishing materials
5.3 Reasons for use
5.4 Typical characteristics of and uses for finishing materials
5.4.1 General
5.4.2 Group (a)
5.4.3 Group (b)
5.4.4 Group (c)
5.4.5 Group (d)
5.5 Finishes for tropical conditions
5.5.1 General
5.5.2 Interior plant in tropical climates
5.5.3 Outdoor plant in tropical climates
5.6 Finishes for refrigeration work
5.7 Finishes to improve fire protective properties
5.8 Finishes for use over pipes in ducts and subways, or beneath buildings
5.9 Ultimate treatment of finish
5.9.1 General
5.9.2 Painting as a final finish
5.9.3 Indoor applications
5.9.4 Outdoor applications
6 Methods of application
6.1 General
6.2 Surface preparation and attachments
6.2.1 Surface preparation
6.2.2 Attachments
6.2.2.1 General
6.2.2.2 Welding gun
6.2.2.3 Arc and gas welding
6.2.2.4 Hand welding
6.2.2.5 Alternative welding
6.2.2.6 Post-weld heat treatment
6.2.2.7 Attachment by adhesive
6.2.2.8 Location of attachments
6.2.2.9 Attachment penetration
6.2.2.10 Thermal movement
6.3 Insulation supports
6.3.1 General
6.3.2 Stud-type supports
6.3.3 Cross-sectional area of supports
6.3.4 Support penetration and thermal bridging
6.3.5 Finishing material support
6.3.6 Securement (tie wires, lacing wire, bands, clips, washers and nuts)
6.3.6.1 General
6.3.6.2 Wires
6.3.6.3 Wire mesh
6.3.6.4 Bands and strips
6.3.6.5 Split-pins
6.3.7 Reinforcement
6.3.7.1 General
6.3.7.2 Wire and mesh size
6.3.7.3 Temperature limitations
6.3.7.4 Mechanical strength
6.3.7.5 Spray-applied bitumen
6.4 Cold insulation: Application for systems operating in the temperature range −75°C to +10°C
6.4.1 General
6.4.1.1 Surface preparation
6.4.1.2 Temperature of application
6.4.1.3 Insulation supports
6.4.1.4 Cutting and fitting
6.4.1.5 Thermal movement
6.4.1.6 Vapour barrier
6.4.2 Adhesives and fastenings
6.4.3 Typical erection methods
6.4.3.1 Using preformed insulating materials
6.4.3.2 Using hot-dip adhesives
6.4.3.3 Using cold adhesives
6.4.3.4 Using bedding compounds
6.4.3.5 Dry erection
6.4.3.6 Pipe supports
6.4.3.7 Vessel supports
6.4.4 Pipework and fittings
6.4.4.1 Pipework
6.4.4.2 Flanges, valves and other fittings
6.4.5 Vessels and large curved surfaces
6.4.6 Airconditioning ductwork (temperature range up to 10°C)
6.4.6.1 General
6.4.6.2 Special coatings
6.4.6.3 Internal insulation
6.4.6.4 External insulation
6.4.6.5 Materials
6.4.6.6 Securement
6.4.6.7 Vapour barrier
6.4.6.8 Typical schemes
6.4.7 Flat and irregular surfaces (including machinery)
6.5 Hot insulation: Application for systems operating in the temperature range +10°C to 800°C
6.5.1 General
6.5.2 Pipework
6.5.2.1 General considerations
6.5.2.2 Preformed materials
6.5.2.3 Castable cements
6.5.3 Flexible materials
6.5.4 Foamed-in-situ
6.5.5 Sprayed insulation
6.5.6 Loosefill insulation
6.5.7 Insulating concrete
6.5.8 Pipes with auxiliary heating
6.5.8.1 General
6.5.8.2 Application of insulation to pipework heated by jacketing, lancing or integral heating
6.5.8.3 Application of insulation to pipework heated by external tracing pipe
6.5.8.4 Electrical tracing
6.5.9 Piping bends
6.5.10 Flanges, valves and other fittings on hot piping
6.5.10.1 General
6.5.10.2 Flange boxes
6.5.10.3 Mattresses
6.5.10.4 Plumbers joint
6.5.10.5 Oversized sections
6.5.10.6 Muff covers
6.5.11 Vessels and large curved surfaces
6.5.11.1 General considerations
6.5.11.2 Preformed materials
6.5.11.3 Castable cement composition
6.5.11.4 Flexible materials
6.5.11.5 Foamed-in-situ
6.5.11.6 Sprayed insulation
6.5.11.6.1 General
6.5.11.6.2 Mineral fibre
6.5.11.6.3 Spray-applied rigid organic foam (polyurethane or isocyanurate)
6.5.11.7 Loosefill insulation
6.5.11.8 Insulating concrete
6.5.12 Airconditioning ducts
6.5.12.1 General
6.5.12.2 Materials
6.5.12.3 External insulation
6.5.12.4 External ductwork
6.5.12.5 Internal insulation
6.5.12.6 Insulation thickness
6.5.12.7 Alternative insulation systems
6.5.12.8
6.5.13 Hot-air ducts (industrial applications) indoor and outdoor
6.5.13.1 General
6.5.13.2 Materials
6.5.13.3 Securement
6.5.13.4 Metal cladding
6.5.13.5 External ductwork
6.5.14 Gas flues (indoor service)
6.5.14.1 General
6.5.14.2 Carbon steel flues
6.5.14.3 Personnel protection system
6.5.15 Gas flues (outdoor service)
6.5.15.1 General
6.5.15.2 Preformed slabs with metal finish
6.5.15.3 Spray-applied bitumen reinforced with glass fibres on a rectangular supporting mesh of metal lath with waterproof paperbacking
6.5.15.4 Preformed slabs with a finish of self-setting cement and bitumen
6.5.15.5 Preformed slabs finished with roofing felt and wire netting or with plastic sheet
6.5.15.6 Metal chimneys
6.5.16 Flat and irregular surfaces (including machinery)
6.5.16.1 General considerations
6.5.16.2 Preformed materials
6.5.16.3 Castable cement compositions
6.5.16.4 Flexible materials
6.5.16.5 Foamed-in-situ
6.5.16.6 Sprayed insulation
6.5.16.7 Loosefill insulation
6.5.16.8 Insulating concrete
7 Finishes — Methods of application
7.1 Indoor finishes
7.1.1 Hard-setting composition or self-setting cement
7.1.1.1 General
7.1.1.2 Hard-setting composition
7.1.1.3 Self-setting cement
7.2 Textile fabrics
7.2.1 Woven scrim fabric
7.2.2 Lightweight canvas and bands
7.2.3 Heavy fabric wrappings
7.3 Plastic sheet and elastomer sheet
7.3.1 General
7.3.2 Rigid sheet
7.3.3 Flexible sheet
7.3.4 Removable insulations
7.3.5 Colour
7.3.6 Tape
7.3.7 Preformed materials
7.4 Mastic and coating finishes
7.4.1 General
7.4.2 Water-based materials
7.4.3 Solvent-based materials
7.4.4 Solvent-free materials
7.5 Metal sheet
7.5.1 General
7.5.2 Mild steel
7.5.3 Alloy steel
7.5.4 Aluminium
7.5.5 Compatibility
7.5.6 Sheet thickness
7.5.7 Application
7.5.8 Securement
7.5.9 Vertical pipework
7.5.10 Flat surfaces
7.5.11 Surface temperatures
7.5.12 Board finishes
7.5.12.1 General
7.5.12.2 Differential expansion
7.5.12.3 Vapour barrier
7.5.12.4 Mechanical properties
7.5.12.5 Surface temperatures
7.6 Weather resistant finishes
7.6.1 Metal sheet
7.6.1.1 General
7.6.1.2 Thermal movement
7.6.1.3 Steel sheet
7.6.1.4 Aluminium sheet
7.6.1.5 Sheet thickness
7.6.2 Weatherproofing compounds
7.6.2.1 General considerations
7.6.2.2 Direct application over insulating material
7.6.2.3 Application over a finish of hard-setting composition
7.6.2.4 Application over a finish of self-setting cement
7.6.3 Self-setting cement
7.6.3.1 General
7.6.3.2 Thermal movement
7.6.4 Plastic and elastomer sheet
7.6.5 Roofing felt and wire netting
7.7 Ultimate treatment of finish painting
Appendix A
A1 Inspection and testing
A2 Site maintenance recommendations
Appendix B
B1 Electrolytic corrosion
B2 Corrosion, stress-corrosion cracking and liquid metal attack
B2.1 General
B2.2 Oxidation
B2.3 Acidic corrosion
B2.4 Alkaline corrosive attack
B2.5 Intergranular corrosion
B2.6 Bimetallic (galvanic) corrosion
B3 Stress-corrosion cracking
B3.1 Action of water-soluble chlorides on austenitic alloy steels
B3.2 Stress-corrosion attack on other metals
B4 Attack by liquid metals
Appendix C
C1 Protection against condensation
C1.1 General
C1.2 Site considerations
C1.3 Sealing
C2 Case descriptions
C2.1 Sugar mill boiler
C2.2 Bread-baking oven
C2.3 Fire-rated bulkhead
C2.4 Oxygen plant
C3 Vapour barriers
C3.1 General
C3.2 Inherent vapour resistance
C3.3 Barrier performance
C3.3.1 General
C3.3.2 Lifetime performance
C3.3.3 Case study: Life of vapour barrier, chilled water pipework
C3.4 Protection from damage
C3.5 Compatibility
C3.6 Breather materials
C3.7 Fire resistance
C3.8 Application
C3.9 Below dewpoint operation
C3.10 Cyclic operation
Appendix D

Cited references in this standard
Content history
DR 95338

AS 4426-1997 REC:2018

Please select a variation to view its description.

Published

05/01/1997

Pages

108

Please select a variation to view its pdf.

AS 4426-1997
$242.18