Standard
Track updates
AS 1228:2016
[Current]Pressure equipment — Boilers
Specifies requirements for materials, design, construction, inspection and testing of boilers as defined in AS/NZS1200.
Published: 18/05/2016
Pages: 278
Table of contents
Cited references
Content history
Table of contents
Header
About this publication
Preface
1 Scope and general
1.1 Scope
1.2 Referenced documents
1.3 Definitions
1.4 Designation
1.5 Valves, gauges, fittings and boiler installation
1.6 Rating
1.7 Information to be supplied by the purchaser
2 Materials and design strengths
2.1 Materials
2.1.1 General
2.1.2 Material identification
2.1.3 Welding materials
2.1.4 Prohibition of use of certain materials
2.1.5 Alternative material specifications
2.1.6 Use of structural or similar quality steels
2.1.7 Specifically tested materials
2.2 Maximum design strength
2.2.1 General
2.2.2 Carbon and carbon-manganese steels
2.2.3 Alloy steels
2.2.4 Cast steels
2.2.5 Design temperature for water-tube boilers
2.2.5.1 General
2.2.5.2 Shells, drums, headers and similar pressure parts
2.2.5.3 Boiler tubes
2.2.5.4 Superheater and reheater tubes
2.2.5.5 Economizer tubes
2.2.5.6 Integral pipes
2.2.5.7 Parts beyond the final superheater header
2.2.6 Design temperature for tube and tube plates for fire-tube boilers
2.2.6.1 Furnace minimum diameter
2.2.6.2 Design temperature
2.3 Design lifetime
3 Design
3.1 Design criteria
3.2 Cylindrical shells, drums and headers subject to internal pressure
3.2.1 Shell thickness
3.2.2 Minimum thickness
3.2.3 Fire-tube and miscellaneous boilers
3.2.3.1 Plate thickness
3.2.3.2 Externally fired boilers plate thickness
3.2.4 Longitudinal ligament efficiency
3.2.4.1 Holes parallel to shell axis
3.2.4.2 Regular drilling
3.2.4.3 Irregular drilling
3.2.4.4 Irregular drilling
3.2.4.5 Compensation
3.2.5 Equivalent longitudinal ligament efficiency for drilling on a diagonal line
3.2.5.1 Regular spacing
3.2.5.2 Regular staggering
3.2.5.3 Irregular drilling not in a straight line
3.2.6 Circumferential ligaments
3.2.7 Combined stresses in drum or header shells
3.2.7.1 General
3.2.7.2 Maximum direct longitudinal stress
3.2.7.3 Resultant bending moment
3.2.7.4 Bending stress
3.2.7.5 Longitudinal stress in supported drum
3.2.7.6 Combined stress
3.2.8 Drum stress due to supports
3.2.9 Other drum stresses
3.2.10 Openings in cylindrical shells
3.2.10.1 General
3.2.10.2 Not Allocated
3.2.10.3 Shape of opening
3.2.10.4 Size of openings
3.2.10.5 Location of openings
3.2.10.6 Orientation of non-circular openings
3.2.10.7 In or adjacent to welds
3.2.11 Unreinforced openings
3.2.11.1 Size of openings
3.2.11.2 Multiple openings
3.2.12 Reinforcement of single openings in shells
3.2.12.1 General
3.2.12.2 Reinforcement area required in shells
3.2.13 Limits of available reinforcement
3.2.13.1 Notation
3.2.13.2 Boundaries of area for reinforcement
3.2.13.3 Limits of reinforcement parallel to vessel wall
3.2.13.4 Limits of reinforcement normal to vessel wall
3.2.13.5 Reinforcing metal
3.2.14 Strength of reinforcement
3.2.15 Reinforcement of multiple openings
3.2.15.1 Two adjacent openings
3.2.15.2 More than two adjacent openings
3.2.15.3 Reinforcement not credited
3.2.15.4 Number and arrangement unlimited
3.2.15.5 Reinforcement by thicker section
3.2.15.6 Series of tube openings
3.2.16 Openings in furnaces of fire-tube boilers
3.2.17 Fillet welds attaching parts, compensating plates and cylindrical shells of boilers
3.3 Dished ends subject to internal pressure
3.3.1 General
3.3.2 Required shape
3.3.3 Thickness
3.3.3.1 General
3.3.3.2 Shape factor
3.3.4 Openings in dished ends
3.3.4.1 Unreinforced openings
3.3.4.2 Reinforced openings
3.3.5 Dished and flanged crowns for vertical boilers
3.3.5.1 Pressure on concave side
3.3.5.2 Pressure on convex side
3.3.5.3 Manhole flanging
3.3.5.4 Firebox crown plate
3.4 Rectangular section headers
3.4.1 Straight rectangular headers
3.4.1.1 Determination of thickness
3.4.1.2 Corner radius
3.4.2 Rectangular headers other than straight
3.5 Header ends
3.5.1 General
3.5.2 Dished ends
3.5.3 Unpierced flat ends
3.5.4 Ends attached by bolting
3.5.5 Reinforcement of openings in flat ends
3.6 Pressure parts of irregular shape
3.6.1 General
3.6.2 Test pressure
3.7 Tubes and integral pipes
3.7.1 Minimum thickness subjected to internal pressure
3.7.2 Tubes subject to external pressure
3.7.3 Bending of boiler, superheater, reheater and economizer tubes
3.7.4 Flexibility of piping systems
3.7.4.1 General
3.7.4.2 Equivalent stress
3.7.4.3 Combined bending and torsion
3.7.4.4 Limiting stresses
3.7.4.5 End reactions
3.7.4.6 Expansion allowance
3.7.5 Fitting and jointing of tubes and integral pipes
3.7.5.1 General
3.7.5.2 Joining of tubes
3.7.5.3 Joints in integral piping
3.8 Structural attachments to tubes
3.8.1 Welding of attachments
3.8.2 Maximum thickness of attachment
3.8.3 Intensity of radial loading
3.8.4 Maximum force due to radial loading
3.8.5 Calculation of weld strengths
3.9 Inspection openings
3.9.1 Access openings water-tube and fire-tube boilers
3.9.1.1 General
3.9.1.2 Size of openings
3.9.1.3 Frames
3.9.1.4 Doors
3.9.2 Externally fitted cover plates
3.9.3 Internally fitted doors
3.9.3.1 General
3.9.3.2 Door thickness
3.9.3.3 Bolting
3.9.3.4 Bridges or dogs
3.9.4 Openings in flat plates of fire-tube boilers
3.9.4.1 Manholes
3.9.4.2 Other openings
3.9.4.3 Dimensions of openings
3.9.5 Inspection and cleaning for fire-tube and miscellaneous boilers
3.9.5.1 General provisions
3.9.5.2 Arrangement for cleaning and inspection
3.9.5.3 Sizes of manholes and inspection openings
3.9.5.4 Required openings in steam space
3.9.5.5 Required openings in water spaces
3.9.5.6 Location of manholes and other openings
3.10 Stays, stiffeners and supported surfaces for fire-tube and miscellaneous boilers
3.10.1 End plates
3.10.1.1 Typical arrangements
3.10.1.2 Typical methods of attachment
3.10.2 Breathing spaces
3.10.2.1 Boilers with gusset stays
3.10.2.2 Internally fired multitubular boilers
3.10.3 Stayed flat surfaces
3.10.3.1 General
3.10.3.2 Radius of flange
3.10.3.3 Point of support
3.10.3.4 Thickness
3.10.3.5 Value of constant
3.10.4 Flat crown plates for vertical boilers
3.10.4.1 General
3.10.4.2 Radius of flange
3.10.4.3 Thickness
3.10.5 Girders for firebox and reversal chamber crowns
3.10.5.1 Girder dimensions
3.10.5.2 Weld dimensions
3.10.5.3 Stress in connections
3.10.6 Stays for fireboxes, circular furnaces and reversal chambers
3.10.6.1 Bar stays for flat plates
3.10.6.2 Circumferential stays for circular furnace and fireboxes
3.10.7 Firebox crown stays and stiffeners for loco-type boilers
3.10.7.1 Stays
3.10.7.2 Stiffeners
3.10.8 Longitudinal bar stays
3.10.8.1 Diameter of bars
3.10.8.2 Bar stays in vertical boilers
3.10.9 Loads on stay tubes and bar stays
3.10.10 Gusset and link stays (corner stays)
3.10.10.1 Load on each stay
3.10.10.2 Gusset stays
3.10.10.3 Link stays
3.10.10.4 Anchor plates, angles and link pins, etc.
3.10.10.5 Weld attachments
3.11 Tubes and tube plate for fire-tube and miscellaneous boilers
3.11.1 Stay tubes and plain tubes
3.11.2 Pitch of tubes
3.11.3 Thickness of tube plates within tube nests
3.11.4 Horizontal shelves of tube plates forming part of the shell
3.11.4.1 Gussets
3.11.4.2 Shell plate thickness
3.11.5 Horizontal tube nests in vertical boilers
3.12 Furnaces, reversal chambers and fireboxes of cylindrical form subject to external pressure
3.12.1 Furnaces
3.12.1.1 Maximum furnace diameter
3.12.1.2 Notation
3.12.1.3 Modulus of elasticity at design temperature
3.12.1.4 Plain furnaces
3.12.1.5 Furnace components
3.12.1.6 Corrugated furnaces
3.12.1.7 Tolerances and corrosion allowances
3.12.1.8 Combination plain and corrugated furnaces
3.12.1.9 Stiffeners
3.12.1.10 Furnace limitations
3.12.2 Circular reversal chambers
3.12.3 Fireboxes and associated components
3.12.3.1 Fireboxes of vertical boilers
3.12.3.2 Uptakes
3.12.3.3 Cross tubes
3.12.3.4 Hemispherical fireboxes
3.12.3.5 Spherical shells under external pressure
3.12.3.5.1 General
3.12.3.5.2 Calculation of elastic instability
3.12.3.5.3 Calculations of membrane yield
3.12.3.6 Dished ends under external pressure (excluding the top end plates of vertical boiler fireboxes) (see Clause 3.3.5)
3.12.3.7 Ogee rings [see Figure 3.12.3(B)(a) and (b)]
3.12.3.8 U-rings
3.12.3.9 Firebox plates under compression
3.13 Boiler settings
3.14 Connections and branches
3.14.1 General
3.14.2 Welded branch connections
3.14.2.1 Application
3.14.2.2 Methods of attachment
3.14.2.3 Pad and branch connections
3.14.2.4 Tell-tale holes
3.14.2.5 Strength of welded connections
3.14.2.6 Set-on, set-through and forged-type branches
3.14.2.7 Reinforced set-on and set-through branches
3.14.2.8 Standard weld details for branches
3.14.3 Screwed connections
3.14.3.1 General
3.14.3.2 Pipe threads
3.14.3.3 Size limitation
3.14.3.4 Temperature limitation
3.14.3.5 Pressure limitation
3.14.3.6 Special pressure limitation
3.14.3.7 Sealing
3.14.3.8 Length of thread engagement
3.14.3.9 Sockets
3.14.4 Socket welded connection
3.14.5 Studded connections
3.14.5.1 General
3.14.5.2 Attachment
3.14.5.3 Studs
3.14.6 Flanged connections
3.14.7 Branch thickness
3.14.8 Take-off connections
3.15 Supporting structures
4 Manufacture and workmanship
4.1 Pressure parts
4.1.1 General
4.1.1.1 Drums and headers
4.1.1.2 Material identification
4.1.2 Cylindrical shells and drums
4.1.2.1 Seamless and forged drums and construction
4.1.2.2 Surface finish and internal soundness
4.1.3 Welded construction
4.1.4 Headers and similar pressure parts
4.1.4.1 General
4.1.4.2 Header ends
4.1.4.3 Extruded openings
4.1.5 Plain tubes and stay tubes for fire-tube and miscellaneous boilers
4.1.5.1 Plain tubes
4.1.5.2 Stay tubes
4.1.6 Welding of stay tubes
4.1.7 Furnaces for fire-tube and miscellaneous boilers
4.1.7.1 Connection to end plate
4.1.7.2 Plain furnaces
4.1.8 Fireboxes for fire-tube and miscellaneous boilers
4.1.8.1 Plain circular fireboxes
4.1.8.2 Spherical fireboxes
4.1.8.3 Loco-type fireboxes
4.1.8.4 Water-cooled combustion chambers
4.1.8.5 Uptakes
4.1.9 Stays for fire tube and miscellaneous boilers
4.1.9.1 Cross tubes
4.1.9.2 Stays
4.1.9.3 Bar stays
4.1.9.4 Firebox stays
4.1.9.5 Gusset stays
4.1.9.6 Girder stays
4.2 Welding
4.2.1 General
4.2.2 Welds of main joints
4.2.3 Welding of pipes and tubes
4.2.3.1 Evaporation tubes
4.2.3.2 Bends
4.2.3.3 Backing rings
5 Inspection and testing
5.1 General
5.2 Non-destructive examination
5.3 Test plates
5.4 Hydrostatic tests
5.4.1 General requirements
5.4.2 Test pressure
5.4.3 Component testing
5.4.4 Requirements for once-through boilers
5.4.4.1 Test pressure for components
5.4.4.2 Test pressure for boiler
5.4.5 Hydrostatic test procedure
6 Documentation and marking
6.1 Drawings, documents, and data sheets
6.2 Certificates
6.3 Marking
6.3.1 General
6.3.2 Marking required
7 Miscellaneous boilers and coil-type forced circulation boilers
7.1 Miscellaneous boilers
7.1.1 General
7.1.2 Electric boilers
7.1.3 Electricity supply
7.1.4 Load adjustment
7.1.5 Current balance
7.1.6 Electrodes, elements and internal parts
7.1.7 Pressure and temperature control
7.1.8 Hydrostatic tests
7.1.9 Access
7.2 Cast iron boilers
7.2.1 General
7.2.2 Maximum design pressure
7.2.3 Maximum design temperature
7.2.4 Materials
7.2.5 Witnessing of bursting tests
7.3 Miniature boilers
7.3.1 General
7.3.2 Designation
7.3.3 Design and construction
7.3.4 Materials
7.3.5 Inspection openings
7.3.5.1 Size and number
7.3.5.2 Internal inspection clearances
7.4 Coil-type forced circulation boilers
7.4.1 General
7.4.2 Limitations
7.4.3 Requirements
7.5 Organic fluid heaters and vaporizers
7.5.1 General
7.5.2 Materials
7.5.3 Design
7.6 Heat recovery steam generators (HRSG)
Appendix A
Appendix B
Appendix C
C1 Information to be supplied by the purchaser
Appendix D
D1 General
D2 Notation
D3 Time-independent design strength
D3.1 General
D3.2 Carbon, carbon-manganese, and low alloy steels
D3.3 Austenitic steels
D4 Time-dependent design strengths
Appendix E
E1 General
E2 Notation
E3 Calculation method
E3.1 Radiation coefficients
E3.2 Convection coefficients
E3.3 Weighted average gas side heat transfer coefficient
E3.4 Tubeplate thermal conductance
E3.5 Water-side heat transfer
E3.6 Tubeplate temperatures
E4 Example of a calculation
E4.1 Design data assumed
E4.2 Calculation of radiation coefficient
E4.3 Calculation of convection coefficients
E4.4 Calculation of weighted average gas-side heat transfer coefficient
E4.5 Calculation of tube plate thermal conductance
E4.6 Calculation of tube plate temperatures
Appendix F
F1 General
F2 Notation
F3 Application
F4 Design for isolated openings and branch connections
F4.1 General
F4.2 Openings not fitted with branches
F4.3 Openings fitted with branches
F4.4 Limits on reinforcement
F4.5 Rim reinforcements
F4.6 Obround, elliptical and oblique openings and nozzles
F4.7 Dissimilar materials
F5 Design of groups of openings and branches
F6 Basis of the design charts for openings and branches (see Paragraph F1)
F6.1 General
F6.2 Isolated openings and branches
F6.2.1 Branches in spherical shells
F6.2.2 Branches in a cylindrical shell
F6.3 Design factors
F6.4 Multiple branches
F6.5 Flush nozzles in cylindrical shells
Appendix G
Appendix H
H1 General
H2 Notation
H3 Design
H3.1 General
H3.2 Narrow saddle top plate
H3.3 Wide saddle top plate
Appendix I
I1 General
I2 Design aspects
I3 Design conditions
I3.1 Vessel design pressure
I3.2 Vessel design temperature
I4 Design recommendations
I4.1 Vessels
I4.2 Vessel shell thickness
I4.3 Inlet branches
I4.4 Vessel and vent pipe guides and supports
Appendix J
J1 General
J2 Evidence of competency
Appendix K
K1 General
K2 Pressure and temperature limits
K3 Use of cast iron
K4 Use of non-ferrous materials
K5 Design strength
K6 Plate thickness
K7 Welded joints
K8 Stays
K9 Pipe and tube thickness
K10 Arch tubes
K11 Boiler carriers and supports
K12 Fabrication
K13 Fittings
K14 Safety valves
K15 Water gauges
K16 Steam pressure gauge
K17 Fusible plugs
K18 Washout and inspection openings
K19 Blowdown equipment
K20 Feedwater system
K21 Hydrostatic test
K22 Steam test
K23 Boiler identification
K24 Boiler rating
K25 Inspection and maintenance
Appendix L
L1 Assumptions
L2 Thickness required based on circumferential stress (see Clause 3.2)
L3 Combined stresses (see Clause 3.2.7)
L4 Stress on diagonal ligaments
L5 Application of irregular drilling not in a straight line (see Clause 3.2.5.3)
Appendix M
M1 General
M2 Failure mode summary
M3 Detailed technical requirements
Cited references in this standard
One-time Purchase
Access via web browser on any device
One-time purchase
Single publication
Offline access via PDF^
$338.44 AUD
Inclusive of GSTFormat *
Web Reader
Licenses *
1 user
Total$338.44 AUD
IMPORTANT