1210 – 1997 Pressure Vessels – Cold –Stretched Austenitic Stainless Steel Vessels

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AS 1210 Supplement 2—1999

Pressure vessels—Cold-stretched

austenitic stainless steel vessels

(Supplement to

AS 1210—1997

)

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was approved on behalf of the Council of Standards Australia on 30 June 1999 and published on 5 September 1999.

The following interests are represented on Committee ME/1: A.C.T. WorkCover

Australasian Corrosion Association

Australasian Institute of Engineer Surveyor Australian Aluminium Council

Australian Building Codes Board

Australian Chamber of Commerce and Industry Australian Industry Group

Australian Institute of Energy Australian Institute of Petroleum

Australian Liquefied Petroleum Gas Association

Boiler and Pressure Vessel Manufacturers Association of Australia Bureau of Steel Manufacturers of Australia

Department for Administration and Information Services, S.A. Department of Employment Training and Industrial Relations, Qld Department of Industries and Business, N.T.

Department of Infrastructure, Energy and Resources, Tas. Department of Labour, New Zealand

Electricity Corporation of New Zealand Electricity Supply Association of Australia Institute of Materials Engineering Australasia Institution of Engineers, Australia

Institution of Professional Engineers, New Zealand National Association of Testing Authorities, Australia New Zealand Engineering Federation

New Zealand Heavy Engineering Research Association New Zealand Institute of Welding

New Zealand Petrochemical Users Group Victorian WorkCover Authority

Welding Technology Institute of Australia WorkCover N.S.W.

WorkSafe Western Australia

Review of Australian Standards. To keep abreast of progress in industry, Australian Standards are subject to periodic review and are kept up to date by the issue of amendments or new editions as necessary. It is important therefore that Standards users ensure that they are in possession of the latest edition, and any amendments thereto.

Full details of all Australian Standards and related publications will be found in the Standards Australia Catalogue of Publications; this information is supplemented each month by the magazine ‘The Australian Standard’, which subscribing members receive, and which gives details of new publications, new editions and amendments, and of withdrawn Standards.

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This Standard was issued in draft form for comment as DR 98308.

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AS 1210 Supplement 2—1999

Pressure vessels—Cold-stretched

austenitic stainless steel vessels

(Supplement to

AS 1210—1997)

Originated as part of SAA Rul PE/1.

Revised and redesignated in part as AS 1210 Supplement 2 — 1999.

Published by Standards Australia (Standards Association of Australia) 1 The Crescent, Homebush, NSW 2140

ISBN 0 7337 2824 3

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PREFACE

This Supplement was prepared by the Joint Standards Australia/Standards New Zealand Committee ME/1, Pressure Equipment to supersede SAA Rul PE/1*, Rulings to the

pressure equipment Standards — Enquiry 101/95 and incorporate requirements for

cold-stretched austenitic stainless steel vessels into AS 1210 — 1997, Pressure vessels as a new

Supplement 2.

In this Supplement, significant changes are made to the above Ruling to take account of recent research, developments and extensive successful experience, and to clarify a number of areas where interpretation difficulties have arisen. These changes are as follows:

(a) Adoption of design factor for tensile strength equal to 2.5. (b) Elimination of minimum amount of cold stretch.

(c) Revision of requirements on thickness variations. (d) Provision for the use of rings and doubling pads.

(e) Provision to utilize increased strength at low temperature. (f) Increased range of temperature application.

(g) Clarification of opening reinforcement.

(h) Introduction of conditions for use in transportable vessels. (i) Alternative fatigue requirements.

(j) Inclusion of selected requirements from Pressure Equipment Note PEN — E15,

Cold-stretched Vessels (now withdrawn) which aimed to clarify a number of matters in

the interim.

The Supplement uses AS 1210 and its Supplement 1 as its general basis of design and manufacture and provides additional or modified requirements and conditions for pressure vessels cold-stretched to enhance proof strength.

Reference should be made to general background information in the prefaces of AS 1210

and Supplement 1.

A supporting technical note is to be prepared to provide answers to a number of queries relating to cold-stretched vessels, to record the background and basis of this Supplement, and to provide some useful references and examples.

Acknowledgment is gratefully made for the assistance provided by the Swedish

Cold-stretching Directive 1991 produced by the Swedish Pressure Vessel Commission.

The sections and clauses in this Supplement (Supplement 2) are prefixed with ‘2S’ as

distinct from clauses in AS 1210 Supplement 1 — 1990, Unfired pressure vessels —

Advanced design and construction, which are prefixed with ‘S’.

* SAA Rul PE/1 is published as a subscription service whereby enquiries from subscribers about the application of pressure equipment Standards are answered. For further information, contact any Standards Australia Office.

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STANDARDS AUSTRALIA

Australian Standard

Pressure vessels — Cold-stretched austenitic stainless steel vessels

(Supplement to

AS 1210 — 1997

)

S E C T I O N

2 S 1

S C O P E

A N D

G E N E R A L

R E Q U I R E M E N T S

Section 1 of AS 1210shall apply, with the following additions to particular Clauses.

2S1.1 SCOPE Clause 1.1 ofAS 1210 applies with the following additions:

Supplement 2 (hereafter referred to as ‘the Supplement’ or ‘this Supplement’) specifies requirements for two additional classes of vessel identified as Class 1S and Class 2SA. This Supplement specifies requirements for pressure vessels designed and fabricated from austenitic stainless steel, cold-stretched to enhance proof strength; and hence permits higher design strengths than those specified in AS 1210 and Supplement 1.

Only those requirements which supplement or differ from those specified in AS 1210 are specified in this Supplement.

2S1.3 APPLICATION Clause 1.3 of AS 1210applies with the following additions: Cold-stretched vessels shall be limited to static and transportable, insulated and non-insulated vessels —

(a) made of austenitic stainless steel cold-stretched after welding is completed (except for small minor welds);

(b) with a maximum nominal wall thickness not exceeding 30 mm; (c) with design temperature not exceeding 400°C;

(d) used only with substances known to have no deleterious effect on the stainless steel of the vessel under the intended service conditions; and

(e) which are not of riveted or brazed construction.

Vessels which contain lethal substances shall be of Class 1S construction.

2S1.6 CLASSES OF VESSEL CONSTRUCTION Clause 1.6 of AS 1210 applies with the following additions:

This Supplement specifies requirements for the following two additional classes of vessel: (a) Class 1S Cold-stretched, with welded joint efficiency as for Class 1 of AS 1210,

and non-destructive examination and fatigue requirements as for Class 1H vessels of AS 1210 Supplement 1.

(b) Class 2SA As for Class 1S but with non-destructive examination and fatigue

requirements as for Class 2HA of AS 1210 Supplement 1.

2S1.7 APPLICATION OF VESSEL CLASSES AND TYPES Clause 1.7 of AS 1210

applies with the following additions to particular Clauses:

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2S1.7.2.4 Mixed classes of welded construction

A vessel may consist of cold-stretched section(s) constructed to Class 1S or 2SA joined to sections or parts constructed to other classes covered by AS 1210 and Supplement 1, provided each part complies with the respective class or classes, and Clause 1.7.2.4 is complied with.

2S1.8 DEFINITIONS Clause 1.8 of AS 1210 applies with the following additions:

2S1.8.32 Cold-stretched pressure vessel — a pressure vessel subjected to a calculated

and controlled internal pressure at ambient temperature (cold-stretching pressure) after completion. This pressure stretches the steel, as necessary, and within limits to raise its proof strength and to ensure that the actual thickness × proof strength satisfies the design.

NOTE: Vessels made of cold-stretched or work hardened plate will normally have very little plastic deformation during cold-stretching.

2S1.8.33 Cold-stretched plate — plate, sheet or strip cold-stretched in a cold-stretching

machine, after solution heat treatment, to a controlled 0.2% residual proof strength e.g. 350–450 MPa (or 400–500 MPa for nitrogen-alloyed steels).

2S1.12 DESIGNATION Clause 1.12 of AS 1210 applies with the following additions: Cold-stretched vessels shall be designated as:

For Class 1S welded construction . . . AS 1210 — 1S. For Class 2SA welded construction . . . AS 1210 — 2SA.

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S E C T I O N

2 S 2

M A T E R I A L S

Section 2 of AS 1210shall apply, with the following additions to the particular Clauses.

2S2.1 MATERIAL SPECIFICATIONS Clause 2.1 of AS 1210 applies with the following additions to particular Clauses.

2S2.1.1 General The material used for pressure parts or parts attached to pressure parts of cold-stretched vessels shall be restricted to one of the types of austenitic stainless steels listed in AS 1210 or an equivalent Standard, e.g. ISO 9328-5.

The steel shall be in the annealed (solution heat-treated) condition with an elongation of not less than 35% on a gauge length of 50 mm or equivalent except for cold-stretched or work hardened plate as specified in this Clause (2S2.1.1).

Only grades which are proven to be metallurgically stable at the intended service temperatures are permitted e.g. ASTM A240 Types 304, 304L, 304LN, 316, 316L, 316LN, 317L, 321, 347 for use between −196°C and +400°C. For other types or lower temperature, suitable type tests shall establish that the properties of parent metal, heat affected zone and weld metal are in accordance with this Supplement after 1000 hours at maximum and minimum design temperatures.

Cold-stretched plate or work hardened (cold rolled) steel may be used provided that the following requirements are satisfied:

(a) The ratio actual 0.2 percent proof strength

actual tensile strength shall not exceed 0.80 .

(b) The maximum hardness shall not exceed that permitted by the original material

specification.

(c) The elongation of the steel as supplied shall be not less than 30 percent on a gauge length of 50 mm or equivalent.

(d) The steel shall be shown, by suitable testing, to have a lateral expansion of at least 0.38 mm at the minimum operating temperature in the final operating condition. Suitable testing by the vessel manufacturer or steel maker shall be at least one set of Charpy tests on the steel type in both the maximum and minimum work hardened conditions, both welded and non-welded.

(e) The vessel manufacturer or steel maker shall document that the steel is suitable for the design and service conditions.

2S2.3 ALTERNATIVE MATERIAL AND COMPONENT SPECIFICATIONS

Clause 2.3 of AS 1210 applies with the following addition.

2S2.3.3 Clause 2.3.3 of AS 1210 does not apply except when permitted by Clause 2.3.4.

2S2.7 MATERIAL FOR HIGH TEMPERATURE SERVICE Clause 2.7 of AS 1210

applies with the following addition.

2S2.7.1 General The maximum service temperature for cold-stretched vessels shall be 400°C.

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S E C T I O N

2 S 3

D E S I G N

Section 3 of AS 1210 with the exception of Clauses 3.8, 3.13 to 3.17 and 3.27 to 3.32 shall apply, with the following additions and modifications to particular Clauses.

2S3.2 DESIGN CONDITIONS Clause 3.2 of AS 1210 applies with the following additions.

S3.2.8 Design for cold-stretching This Clause provides additional design requirements for cold-stretched vessels. Specific reference should also be made to Clause 3.2.5 (low-temperature service) of AS 1210.

Particular care shall be taken to ensure that all openings and attachments (e.g. nozzles, pads and supports) are designed, located and fabricated so as to avoid discontinuities and sudden changes in stiffness or rigidity and to limit localized strain to 10% particularly in the circumferential direction. Calculations for the vessel support system shall be subjected to design verification. The calculations shall take account of all combinations of stresses due to restraint, discontinuities, thermal effects and vessel loadings including those under normal operating conditions and cold stretching.

It is recommended that, where practical, attachment welds be arranged axially where possible to allow free stretching.

In addition to the design requirements specified in this Supplement, it shall be shown by calculation or test that the permanent strain from cold stretching will not exceed 10% in areas of local strain concentration, except this is not required for dished ends complying with this Supplement.

NOTE: The amount of local strain may be determined in accordance with AS 1210

Supplement 1,BS 5500 or equivalent.

The vessel shall meet the fatigue requirements of Clause S3.1.5 of AS 1210 Supplement 1

or BS 5500 or equivalent.

The vessel shall be constructed to Class 1 requirements of AS 1210 except where this Supplement specifies other requirements.

2S3.3 DESIGN STRENGTHS Clause 3.3 of AS 1210 applies with the following modification.

2S3.3.1.1 General

For cold-stretched pressure vessels the maximum allowable design tensile strength (f) shall be:

(a) For design temperatures up to and including 20°C, f is the lower of:

Re/1.5 (Note 1); and

. . . 2S3.3.1(1)

R_m (Note 2) 2.5 (Note 3)

(b) For temperatures over 20°C and up to and including 400°C, the value from Item (a) shall be reduced by the amount in Table 2S3.3.1.

(c) For temperatures below 0°C, the provisions of Clause 3.33 of AS 1210 may also be applied.

NOTES:

1 Re = specified minimum yield or proof stress (0.2% offset) at 20°C in the solution

heat-treated condition, or in the specified supply condition, or it may be taken as the stress actually developed at the cold-stretch pressure.

2 Rm = specified minimum tensile strength at 20°C in the solution heat-treated condition or in

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plate used in the vessel, as recorded on the steel maker’s material test certificate. In this case the actual tensile strength is also limited to 125% of Rm. Also suitable tests are

required to assess the actual strength of formed ends or other parts where fabrication methods may reduce tensile strength.

3 The factor 2.5 may be changed to 2.25 under the following conditions: (a) f does not exceed 258 MPa.

(b) Hydrostatic test pressure is not less than 1.5 × calculation pressure for all parts of the shell and ends.

(c) Design temperature does not exceed 20°C and the design minimum temperature is below −50°C.

(d) At least two pressure relief devices are fitted, one set at the design pressure (within allowable tolerance) and the other not greater than 1.21 times the design pressure. (e) If the vessel is transportable, it also has external mechanical and thermal protection as

specified in Clause 2S3.26.

TABLE 2S3.3.1

DESIGN TENSILE STRENGTH REDUCTION VALUES

Steel type (ASTM A240)

Design tensile strength, reduction values, MPa Design temperature °C 20 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 Standard types 304, 304L, 316. 316L 0 40 55 70 80 90 100 110 115 120 125 130 135 140 145 150 Ti or Nb - Alloyed types 321, 347 0 30 40 50 58 65 72 80 82 85 88 90 92 95 98 100 N - Alloyed types 304LN, 316LN 0 60 80 100 112 125 138 150 158 165 172 180 188 195 202 210

2S3.5 WELDED AND BRAZED JOINTS Clause 3.5 of AS 1210 applies with the following additions and modifications.

2S3.5.1.3 Location of joints Special reference should be made to Clause 3.5.1.3 of

AS 1210.

2S3.5.1.4.6 Welded joints with backing strips Joggled joints shall not be used. Circumferential joints with retained backing strips may be used.

2S3.5.1.8 Butt-weld between plates of unequal thickness The thickness of plates in adjacent shell strakes and in ends of cold-stretched vessels may be varied provided — (a) all plates in any one strake or in an end are the same nominal thickness;

(b) the difference in thickness between plates in adjacent shell strakes do not exceed 20 percent of the thickness of the thinner plate; and

(c) weld details between plates of different thickness comply with Clause S3.5.1.8 of

AS 1210 Supplement 1.

NOTE: The thickness of ends and adjacent shell strakes is not limited by Item (b). COPYRIGHT

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2S3.5.3 Brazed joints Brazed joints shall not be used in cold-stretched vessels except for attached piping.

2S3.5.4 Soldered joints Soldered joints shall not be used in cold-stretched vessels except for attached piping.

2S3.7 CYLINDRICAL AND SPHERICAL SHELLS SUBJECT TO INTERNAL PRESSURE AND COMBINED LOADINGS Clause 3.7 of AS 1210 applies with the following additions.

2S3.7.5 Vertical cylindrical vessels under combined loading For cold-stretched vessels, suitable provision shall be made to avoid axial buckling due to shells distorted unequally by stretching. See Clause 2S3.7.6 for design for hydrotesting in the horizontal position.

2S3.7.6 Horizontal cylindrical vessels under combined loading Additionally, the design shall cater for axial buckling during hydro stretching and for modified shell shape.

2S3.8 THICK-WALLED CYLINDRICAL AND SPHERICAL VESSELS SUBJECT TO INTERNAL PRESSURE Clause 3.8 of AS 1210does not apply.

2S3.9 CYLINDRICAL AND SPHERICAL SHELLS SUBJECT TO EXTERNAL PRESSURE Clause 3.9 of AS 1210applies with the following modifications.

2S3.9.2 Notation The value of f shall be taken as that given inAS 1210, Clause 3.9.2.

2S3.9.6.2 Form of stiffening rings Circumferential rings are permitted as stiffeners or supports of cold-stretched shells provided the rings are complete so that no openings or notches are formed which cause localized strain in the shell or ring in excess of 10%. Any openings or notches in the rings should be located clear of joints in the ring and shall be smooth. The joints in the ring itself shall be full penetration welds, subject to radiography before stretching and to close visual examination after stretching, where accessible. Toes of welds on the shell plate, of welds attaching the ring to shell, shall blend smoothly and be free of undercut. See Clause 2S3.25.

2S3.12 DISHED ENDS SUBJECT TO INTERNAL PRESSURE Clause 3.12 of

AS 1210 applies with the following addition.

2S3.12.1 General Ends shall be spherical or ellipsoidal with an outside major to minor axis ratio not greater than 2:1.

CLAUSES 2S3.13 TO 2S3.17 INCLUSIVE Clauses 3.13 to 3.17 of AS 1210 do not apply to cold-stretched vessels.

2S3.18 OPENINGS AND REINFORCEMENTS Clause 3.18 of AS 1210 applies with the following additions and modifications:

NOTE: Allowance should be made for possible distortion of the opening and nozzle, e.g. by use of reduced value off.

2S3.18.5 Location of openings Any opening exceeding 325 mm diameter shall be located in the end of the vessel and shall be concentric with the vessel shell except where proof is provided that the local strain in the end does not exceed 10%. Additionally, designs should aim to have all attachments fitted to the vessel ends wherever this is practicable.

2S3.18.6 Unreinforced openings Unreinforced openings shall comply with Clause S3.18.6 of AS 1210 Supplement 1.

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opening by increased nozzle wall thickness is preferred in all cases. Doubling plates or pads (or reinforcing rings around the nozzle) should be avoided where practicable to prevent excessive local strain in the shell near the pad.

2S3.18.7 Reinforcement of single openings in shells and dished ends For cold-stretched vessels the design of openings and reinforcements shall be on the area replacement method (i.e. plastic design) assuming the shell and nozzle have an ‘f ’ value not in excess of that in Clause S3.3.1.1.

2S3.19 CONNECTIONS AND BRANCHES Clause 3.19 of AS 1210 applies with the following addition.

2S3.19.3.4 Tell-tale holes Tell-tale holes are not required in internal doubling or

wrapper plates where heat treatment is not required and avoidance of content

contamination is necessary.

2S3.23 JACKETED VESSELS Clause 3.23 of AS 1210 applies but not for partially jacketed cold-stretched vessels.

2S3.24 VESSEL SUPPORTS Clause 3.24 of AS 1210 applies in conjunction with Clause 2S3.25.

2S3.25 ATTACHED STRUCTURES AND EQUIPMENT Clause 3.25 of AS 1210

applies with the following additions.

2S3.25.4 Attachment for cold-stretched vessels Rings and similar structural parts attached to cold-stretched shells or ends shall comply with the following:

(a) Clause 3.9 ofAS 1210 for rings designed for prevention of buckling.

(b) Clause 3.24.4 of AS 1210, AS 3990, or other appropriate reference for supports using design strength (‘f’ ) as in AS 1210 or AS 1210 Supplement 1 (as desired) at a design temperature equal to —

(i) at least 20°C, to ensure adequacy at the combined pressure and loading

during the hydro or other pressure test; and

(ii) the highest temperature of liquid adjacent to the vessel part under coincident service pressure and load conditions, e.g. for cryogenic transportable vessels,

supports and internal stiffeners may be designed for the required ‘G’

loading, with ‘f ’ at the boiling point of the contained gas at the safety valve pressure setting.

(c) As an alternative to Item (b), comply with AS 4100 but with yield strength equal to the 1% proof strength of the steel at the temperatures specified in Item (b).

(d) Calculations for support rings shall include determination of transverse bending stress in the ring flange.

(e) Welds attaching rings to the shell shall be continuous on both sides of the web with a minimum total throat thickness equal to the web thickness. See Clause 2S3.19.3.4

2S3.26 TRANSPORTABLE VESSELS Clause 3.26 of AS 1210 applies with the following additions.

2S3.26.3.1 Class of construction Transportable vessels for the carriage of products by road, rail or sea can be manufactured as cold-stretched stainless steel vessels shall be Class 1S construction in place of Class 1 and Class 2SA in place of Class 2A and 2B.

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(c) The design shall be assessed and comply with the fatigue requirements of Clause 2S3.2.8 taking into account actual shape of welds permitted, local distortion, location of attachments and the additional transport loads. This shall also apply to the supports.

(d) Before use with lethal or very harmful fluids (see AS 4343), the design shall be proven by operation of a vessel fully representative of the design and construction, for a service period of at least one year using fluid other than lethal or very harmful; or by accelerated fatigue testing a full size vessel under equivalent loading and cycling.

(e) For ISO tank container type pressure vessels, the total assembly of the frame and vessel shall meet the requirements of the relevant authority for the particular mode of transport to be carried by sea and the relevant rail authority for containers to be carried by rail.

(f) For vessels covered by Item (e), the design strength ‘f’ used in the design of shells and ends shall comply with IMDG code; and the thickness of the shell and ends (or the combined wall thickness of jacket and the shell or ends of a vacuum insulated vessel) tmin shall be not less than —

(i) 5 mm;

(ii) that required in Clause 3.4.3; and

(iii) for shell and ends over 1000 mm diameter in contact with the pressurized contents not less than that given by Equation 2S3.26:

. . . 2S3.26

t_min = C

3

R_m × A where

A = guaranteed minimum percentage elongation (L = 5d)

C = 107 for vessels ≤1.8 m diameter

C = 128 for vessels >1.8 m diameter

C = 64 for vacuum insulated vessels ≤1.8 m diameter

C = 85 for vacuum insulated vessels >1.8 m diameter

R_m = ‘guaranteed’ minimum tensile strength at design temperature, in

megapascals

tmin = minimum thickness of shell and ends at design temperature, in

millimetres

(g) The type of material, its design strength, thickness and any insulation shall be sufficient to give a period of at least 15 minutes from the time of fire engulfment to rupture of the shell. The rupture of the shell shall not result in fragmentation. Supporting calculations or tests shall be made but are not required for Item (h)(i) or (ii) where the jacket metal is of steel.

Calculations shall be based on any insulation provided being intact except for loss of any vacuum, uninsulated gas backed surfaces reaching 650°C, the pressure equalling the design pressure, and reasonably reliable short-term mean creep rupture data of the steel at 650°C.

(h) Transportable non-vacuum, cold-stretched vessels shall have external protection against impact at least equivalent to —

(i) 2 mm metal jacket with 100 mm powder or fibre insulation; (ii) 2.5 mm metal jacket with multi-layer (super) insulation; or

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100 mm rigid fire retardant foam.

NOTE: Insulation for impact may also be used for fire protection.

For lethal or very harmful (toxic or flammable) contents, the combined thickness of the metal jacket and the vessel wall shall be at least 9 mm. The minimum thickness of the metal jacket shall be 2 mm.

For harmful or non-harmful contents, the combined thickness of the metal jacket and vessel wall shall be at least 7 mm.

CLAUSES 2S3.27 TO 2S3.32 INCLUSIVE Clauses 3.27 to 3.32 of AS 1210 do not apply to cold-stretched vessels.

2S3.33 VESSELS WITH INCREASED DESIGN STRENGTH AT LOW TEMPERA-TURE Clause 3.33 of AS 1210 applies with the provision that alternative reliable and conservative strength values for cold-stretched steel may be used where fully justified at design verification.

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S E C T I O N

2 S 4

M A N U F A C T U R E

Section 4 of AS 1210 shall apply with the following additions and modifications to particular Clauses.

2S4.2 WELDED CONSTRUCTION Clause 4.2 of AS 1210 applies with the following addition and modification.

2S4.2.1 General welding requirements Butt weld reinforcement limits to AS 1210

and AS 4458 apply, but lower values are recommended for longitudinal type welds. Dressing of welds is only required where necessary to meet these limits or the shape required by fatigue design.

2S4.5 BRAZED CONSTRUCTION Brazing shall not be used on main shells and ends of cold-stretched vessels.

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S E C T I O N

2 S 5

T E S T I N G

A N D

Q U A L I F I C A T I O N

Section 5 of AS 1210 shall apply, with the following additions and modifications to particular Clauses.

2S5.3 NON-DESTRUCTIVE EXAMINATION Clause 5.3 of AS 1210 applies with the following additions:

Each vessel after cold-stretching shall be examined at accessible surfaces at the circumferential rings (and other areas of potential high localized strain) to ensure local strain has not exceeded the 10% limit.

Radiographic examination shall be done before the hydrostatic test. In Class 1S vessels, longitudinal and circumferential type welds shall have 100% radiographic examination. In Class 2SA vessels longitudinal type welds shall have 100% radiographic examination and circumferential type welds shall have at least 10% radiographic examination. All tee joints shall be radiographed.

Penetrant examination shall be done after the hydrostatic test at areas which are accessible and the local strain may exceed 5%.

2S5.10 HYDROSTATIC TESTS Clause 5.10 of AS 1210 applies with the following addition and modification.

2S5.10.2.1 Hydrostatic test — Single wall vessels designed for internal pressure

The vessel shall be hydrostatically tested and cold-stretched at the higher pressure calculated in accordance with Equations 2S5.10.2.1(1) and 2S5.10.2.1(2).

. . . 2S5.10.2.1(1) p_h 1.5 p × fh f . . . 2S5.10.2.1(2) p_h = 1.5 fh f (p + hgρ 10 −6_{) − h} h gρh 10 −6 where

ph = hydrostatic test pressure at the top of the vessel, in megapascals p = design pressure of the vessel at the top of the vessel, in megapascals

fh/f = lowest ratio (for the materials of which the vessel is constructed) of —

design strength at test temperature, MPa design strength at design temperature, MPa

(Values to be taken from Table 2S3.3.1 or as used in the design.)

h = maximum head of liquid in service, in metres

hh = actual head of test liquid, in metres

ρ = density of liquid in service, in kilograms per cubic metre ρh = density of test liquid, in kilograms per cubic metre g = 9.81, in metres per second per second

The test pressure shall be maintained until the measured strain rate does not exceed 0.1% per hour.

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The total circumferential strain shall be determined during pressuring and depressuring by measuring the general increase in circumference of at least one strake of each nominal thickness at positions which are judged to have minimum restraint.

NOTE: In a vessel which does not have circumferential stiffening, the above mentioned locations will normally be at the mid-length of the shell strakes having the lowest value of plate thickness multiplied by proof strength (from the steel makers certificates). To facilitate measurement this strake may be located at the bottom of large vessels tested in the vertical position.

The total permanent circumferential strain based on the general increase in circumference shall not exceed 5 percent. See also Clause 2S5.4.

In the event the required test pressure is not reached at 5.2% total strain, the vessel shall be modified, rejected or derated to a design pressure equal to 1 times the maximum test

1.5 pressure reached at 5.2% total strain.

2S5.11 PNEUMATIC TESTS Clause 5.11 of AS 1210 applies with the following modification:

Pneumatic cold-stretching and testing shall not be used unless done in a safe explosion resistant enclosure or under equivalent conditions and in accordance with a fully documented procedure which will ensure no injury in the event of unexpected failure.

2S5.17 SPECIAL EXAMINATIONS AND TESTS Clause 5.17 of AS 1210 applies with the following addition:

A full scale test shall be made to ensure the transverse strain at the toes of fillet welds attaching a circumferential ring to the shell are within strain limits. Measurements to check this strain shall be taken after completion of the cold-stretch/hydrostatic test at a point located on the vessel wall showing maximum curvature from the original shape. This location may be determined by visual inspection and shall account for any welding distortion which may be present before cold stretching is carried out. This test may be made on one completed vessel with the highest total circumferential strain or may be made on a representative test specimen made of the same materials and thickness.

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S E C T I O N

2 S 6

A S S U R A N C E

O F

P R O D U C T

Q U A L I T Y

Section 6 of AS 1210shall apply.

S E C T I O N

2 S 7

M A R K I N G

Section 7 of AS 1210shall apply, with the following additions and modifications:

2S7.1 MARKING REQUIRED Clause 7.1 of AS 1210 applies with the following addition:

In addition to the marking required by Clause 7.1 of AS 1210, each vessel shall be marked with the maximum permanent strain actually measured e.g. ‘1.2% max cold stretch’.

2S7.7 REPORTS The Manufacturers Data Report (see AS 4458) shall show the marking specified in Clause 2S7.1 and the location of this strain.

A record of the pressurizing sequence including measured pressures and circumferential measurements versus time and strain rate shall be kept by the manufacturer.

S E C T I O N

2 S 8

P R O T E C T I V E

D E V I C E S

A N D

O T H E R

F I T T I N G S

S E C T I O N

2 S 9

P R O V I S I O N S

F O R

D E S P A T C H

S E C T I O N

2 S 1 0

N O N - M E T A L L I C

V E S S E L S

Section 10 does not apply, except Clause 10.2(a) of AS 1210 for non-metallic components of cold-stretched vessels.

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APPENDICES

The Appendices of AS 1210 shall apply with the following addition to the particular Appendix.

APPENDIX 2SR

LIST OF REFERENCED DOCUMENTS

Appendix R of AS 1210 shall apply with the following addition:

AS

4343 Pressure equipment — Hazard levels

ISO

9328 Steel plates and strip for pressure purposes — Technical delivery conditions 9328-5 Part 5: Austenitic steels

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1210 – 1997 Pressure Vessels – Cold –Stretched Austenitic Stainless Steel Vessels

AS 1210 Supplement 2—1999

Pressure vessels—Cold-stretched

austenitic stainless steel vessels

(Supplement to

AS 1210—1997

)

AS 1210 Supplement 2—1999

Pressure vessels—Cold-stretched

austenitic stainless steel vessels

(Supplement to

AS 1210—1997)

PREFACE

CONTENTS

STANDARDS AUSTRALIA

Australian Standard

Pressure vessels — Cold-stretched austenitic stainless steel vessels

(Supplement to

AS 1210 — 1997

)

S E C T I O N

2 S 1

S C O P E

A N D

G E N E R A L

R E Q U I R E M E N T S

S E C T I O N

2 S 2

M A T E R I A L S

S E C T I O N

2 S 3

D E S I G N

S E C T I O N

2 S 4

M A N U F A C T U R E

S E C T I O N

2 S 5

T E S T I N G

A N D

Q U A L I F I C A T I O N

S E C T I O N

2 S 6

A S S U R A N C E

O F

P R O D U C T

Q U A L I T Y

S E C T I O N

2 S 7

M A R K I N G

S E C T I O N

2 S 8

P R O T E C T I V E

D E V I C E S

A N D

O T H E R

F I T T I N G S

S E C T I O N

2 S 9

P R O V I S I O N S

F O R

D E S P A T C H

S E C T I O N

2 S 1 0

N O N - M E T A L L I C

V E S S E L S

LIST OF REFERENCED DOCUMENTS