ISO 9330-4:2000

Welded steel tubes for pressure purposes - Technical delivery conditions - Part 4: Submerged arc-welded unalloyed and alloyed steel tubes with specified elevated temperature properties

This part of ISO 9330 specifies the technical delivery conditions for submerged arc-welded tubes of circular crosssection, made of unalloyed or alloyed steel with specified elevated temperature properties. These tubes are intended for pressure purposes in cases when the material is also subjected to elevated temperatures, e.g. for the construction of steam generating equipment and for interconnecting pipework. The requirements of appropriate international application standards and relevant national legal regulations shall be taken into account by the user. For boilers and pressure vessels International Standards ISO 831, ISO 2604 and ISO 5730 are available. For the general technical delivery requirements, see ISO 404. NOTE The English words "tube" and "pipe" are synonymous.

Tubes en acier soudés pour service sous pression — Conditions techniques de livraison — Partie 4: Tubes soudés à l'arc immergé en aciers non alliés et alliés avec caractéristiques spécifiées à température élevée

General Information

• Status: Published
• Publication Date: 12-Jul-2000
• ICS: 23.040.10 - Iron and steel pipes
• ICS: 77.140.75 - Steel pipes and tubes for specific use
• Technical Committee: ISO/TC 17/SC 19 - Technical delivery conditions for steel tubes for pressure purposes
• Drafting Committee: ISO/TC 17/SC 19 - Technical delivery conditions for steel tubes for pressure purposes
• Current Stage: 9060 - Close of review
• Completion Date: 03-Mar-2028

Overview

ISO 9330-4:2000 defines the technical delivery conditions for submerged arc-welded (SAW) welded steel tubes for pressure purposes that require specified elevated temperature properties. It covers circular-section tubes made from unalloyed and alloyed steels intended for pressure systems exposed to high temperatures (for example, steam-generating equipment and interconnecting pipework). The standard specifies manufacturing, metallurgical, dimensional, testing and inspection requirements to ensure fitness for elevated-temperature pressure service.

Key Topics and Requirements

• Scope and applicability: SAW tubes for pressure purposes where the material will operate at elevated temperatures. Notes that “tube” and “pipe” are synonymous.
• Purchaser information: Mandatory order data (denomination “tube”, dimensional standard, outside diameter × wall thickness, length, ISO 9330-4 reference, steel grade, test category). Optional items include product analysis, impact testing, proof stress at elevated temperature, special marking and coatings.
• Manufacture & condition:
  • Tubes must be submerged arc-welded with at least one run inside and one outside.
  • May be hot- or cold-finished; delivery conditions include as‑welded, normalized, or normalized+tempered depending on grade.
• Metallurgical requirements:
  • Heat and product chemical analysis limits and permitted deviations for listed grades (e.g., PH 23, PH 26, PH 29, PH 35, 16Mo3, 13CrMo4-5, 11CrMo9-10).
  • Fully-killed steels required.
• Mechanical testing & inspection:
  • Tensile testing (ambient and elevated temperature methods referenced).
  • Impact tests, bend tests, hydraulic tests and long-term rupture values (informative Annex A).
  • Non-destructive testing of the weld: ultrasonic (ISO 9765, ISO 12094) and radiographic (ISO 12096).
  • Inspection documentation per ISO 10474 (e.g., 3.1.B).
• Dimensions & tolerances: References ISO 4200 and ISO 5252 for dimensional tables and tolerance systems.
• Marking, protection and documentation: Requirements for marking, protective treatment and delivery documents.

Applications and Users

• Typical applications: boilers, pressure vessels, steam generators and high-temperature piping in power plants, petrochemical and industrial process systems.
• Primary users: tube manufacturers, steel mills, pressure-equipment designers, procurement/specification engineers, weld inspectors, certifying bodies and fabricators who need steel tubes suitable for elevated-temperature pressure service.

Related Standards

• ISO 404 - General technical delivery requirements
• ISO 4200 - Plain end steel tubes-dimensions and masses
• ISO 10474 - Inspection documents for steel products
• ISO 6892, ISO 783 - Tensile testing (ambient and elevated temp)
• ISO 9765, ISO 12094, ISO 12096 - Ultrasonic and radiographic testing of weld seams/ends
• ISO 831, ISO 2604, ISO 5730 - Standards relevant to boilers and pressure vessels

Keywords: ISO 9330-4, submerged arc-welded, welded steel tubes, elevated temperature properties, pressure purposes, technical delivery conditions, steam generating equipment, weld inspection.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 9330-4
First edition
2000-07-01
Welded steel tubes for pressure
purposes — Technical delivery
conditions —
Part 4:
Submerged arc-welded unalloyed and
alloyed steel tubes with specified elevated
temperature properties
Tubes en acier soudés pour service sous pression —
Conditions techniques de livraison —
Partie 4: Tubes soudés à l'arc immergé en aciers non alliés et alliés avec
caractéristiques spécifiées à température élevée
Reference number
©
ISO 2000
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ii © ISO 2000 – All rights reserved

Contents Page
Foreword.iv
1 Scope .1
2 Normative references .1
3 Symbols .2
4 Information to be supplied by the purchaser .3
5 Manufacturing process .4
6 Metallurgical properties .6
7 Dimensions, masses and tolerances.10
8 Technical delivery conditions .12
9 Inspection and testing.13
10 Samples .15
11 Test methods and results .17
12 Marking .22
13 Protection .22
14 Documents .22
Annex A (informative) Long term rupture values.23
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this part of ISO 9330 may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 9330-4 was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 19,
Technical delivery conditions for steel tubes for pressure purposes.
ISO 9330 consists of the following parts, under the general title Welded steel tubes for pressure purposes —
Technical delivery conditions:
� Part 1: Unalloyed steel tubes with specified room temperature properties
� Part 2: Electric resistance and induction welded unalloyed and alloyed steel tubes with specified elevated
temperature properties
� Part 3: Electric resistance and induction welded unalloyed and alloyed steel tubes with specified low
temperature properties
� Part 4: Submerged arc-welded unalloyed and alloyed steel tubes with specified elevated temperature
properties
� Part 5: Submerged arc-welded unalloyed and alloyed steel tubes with specified low temperature properties
� Part 6: Longitudinally welded austenitic stainless steel tubes
Annex A of this part of ISO 9330 is for information only.
iv © ISO 2000 – All rights reserved

INTERNATIONAL STANDARD ISO 9330-4:2000(E)
Welded steel tubes for pressure purposes — Technical delivery
conditions —
Part 4:
Submerged arc-welded unalloyed and alloyed steel tubes
with specified elevated temperature properties
1 Scope
This part of ISO 9330 specifies the technical delivery conditions for submerged arc-welded tubes of circular cross-
section, made of unalloyed or alloyed steel with specified elevated temperature properties. These tubes are
intended for pressure purposes in cases when the material is also subjected to elevated temperatures, e.g. for the
construction of steam generating equipment and for interconnecting pipework.
The requirements of appropriate international application standards and relevant national legal regulations shall be
taken into account by the user. For boilers and pressure vessels International Standards ISO 831, ISO 2604 and
ISO 5730 are available.
For the general technical delivery requirements, see ISO 404.
NOTE The English words “tube” and “pipe” are synonymous.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this part of ISO 9330. For dated references, subsequent amendments to, or revisions of, any of these publications
do not apply. However, parties to agreements based on this part of ISO 9330 are encouraged to investigate the
possibility of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain
registers of currently valid International Standards.
1)
ISO 148:1983 , Steel — Charpy impact test (V-notch).
ISO 377:1997, Steel and steel products — Location and preparation of samples and test pieces for mechanical
testing.
IS0 404:1992, Steel and steel products — General technical delivery requirements.
ISO 783:1999, Metallic materials — Tensile testing at elevated temperature.
ISO 2566-1:1984, Steel — Conversion of elongation values — Part 1: Carbon and low alloy steels.
ISO 3205:1976, Preferred test temperatures.
1) This International Standard has been withdrawn and replaced by ISO 148-1:—, ISO 148-2:1998 and ISO 148-3:1998.
ISO 3545-1:1989, Steel tubes and fittings — Symbols for use in specifications — Part 1: Tubes and tubular
accessories with circular cross-section.
ISO 4200:1991, Plain end steel tubes, welded and seamless — General tables of dimensions and masses per unit
length.
ISO 4948-1:1982, Steels — Classification — Part 1: Classification of steels into unalloyed and alloy steels based
on chemical composition.
ISO/TR 4949:1989, Steel names based on letter symbols.
ISO 5173:1981, Fusion welded butt joints in steel — Transverse root and face bend test.
ISO 5177:1981, Fusion welded butt joints in steel — Transverse side bend test.
ISO 5252:1991, Steel tubes — Tolerance systems.
ISO 6761:1981, Steel tubes — Preparation of ends of tubes and fittings for welding.
ISO 6892:1998, Metallic materials — Tensile testing at ambient temperature.
ISO 7438:1985, Metallic materials — Bend test.
ISO 9765:1990, Submerged arc-welded steel tubes for pressure purposes — Ultrasonic testing of the weld seam
for the detection of longitudinal and/or transverse imperfections.
ISO 10474:1991, Steel and steel products — Inspection documents.
ISO 11496:1993, Seamless and welded steel tubes for pressure purposes — Ultrasonic testing of tube ends for the
detection of laminar imperfections.
ISO 12094:1994, Welded steel tubes for pressure purposes — Ultrasonic testing for the detection of laminar
imperfections in strip/plates used in the manufacture of welded tubes.
IS0 12096:1996, Submerged arc-welded steel tubes for pressure purposes — Radiographic testing of the weld
seam for the detection of imperfections.
ISO 14284:1996, Steel and iron — Sampling and preparation of samples for the determination of chemical
composition.
3 Symbols
3.1 Fundamental symbols
D is the specified outside diameter.
T is the specified wall thickness.
3.2 Symbols for tolerances
See ISO 5252.
2 © ISO 2000 – All rights reserved

3.3 Symbols for tests
3.3.1 Tensile test
See ISO 6892.
3.3.2 Hydraulic test
p is the test pressure.
E
� is the stress which occurs in the metal during the test.
4 Information to be supplied by the purchaser
4.1 Mandatory information
The purchaser shall state on his enquiry and order the following information:
a) the denomination “tube”;
b) reference to the relevant dimensional standard;
c) dimensions (outside diameter � wall thickness), see 7.1;
d) length, see 7.2;
e) tolerances if exact lengths greater than 12 m are ordered, see 7.3.4;
f) reference to this part of ISO 9330, i.e. ISO 9330-4;
g) steel grade, see Table 3;
h) test category for unalloyed steels, see 9.3.1.
4.2 Optional information
Enquiries and orders for tubes in accordance with this part of ISO 9330 shall be supplemented, if it is deemed
necessary by the purchaser, with the indication of one or more of the following optional requirements, which shall
be the subject of special agreements:
a) dimensions (inside diameter � wall thickness) see 7.1;
b) steelmaking process, see 5.1;
c) delivery condition, see 5.4;
d) special straightness requirements, see 7.3.6;
e) tolerances on the height of the weld seam, see 7.3.2;
f) bevelled ends, see 8.2;
g) product analysis, see 10.1.3;
h) tensile testing of weld for tubes over 219 mm but less than 508 mm outside diameter, see 10.1.3;
i) determination of proof stress at elevated temperature R , see 10.1.3;
p0,2
j) impact test, see 10.1.3;
k) specific marking, see 12.3;
l) protective coating, see 13;
m) type of inspection and testing and corresponding document, see 9.2 and 14.
4.3 Example of an order
Example of an order conforming to the dimensional standard ISO 4200, with an outside diameter of 457 mm, a wall
thickness of 10 mm and a standard length (random length) of 4 m to 8 m, made of steel grade PH 23 with specified
elevated temperature properties to be submitted to specific inspection and testing to test category I involving the
issuing of an inspection document 3.1 B in accordance with ISO 10474:1991.
Tube ISO 4200 - 457 ����10-4to 8- ISO9330-4- PH23-l-3.1.B
5 Manufacturing process
5.1 Steelmaking process
If requested, the purchaser shall be informed of the steelmaking process used.
Steels may be cast in ingots or may be strand cast. When steels of different grades are sequentially strand cast
identification of the resultant transition material is required. The producer shall remove the transition material by an
established procedure that positively separates the grades.
5.2 Deoxidation process
Steels intended for the production of tubes covered by this part of ISO 9330 shall be fully-killed.
5.3 Product-making process for tubes
A welded tube is obtained by shaping a flat-rolled product and then welding the edges. The weld may be
longitudinal or helical.
Tubes shall be submerged arc-welded (SAW) using at least one run on the inside and one run on the outside of the
tube. Unless otherwise agreed, the process of manufacture is left to the discretion of the manufacturer, provided
that the welding method and welder/welding operator have been approved in accordance with a qualified
procedure.
Tubes covered by this part of ISO 9330 may be hot finished or cold finished. The terms “hot finished” and “cold
finished” apply to the condition of the tube before it is heat treated, if applicable.
5.4 Delivery condition
5.4.1 Tubes covered by this part of ISO 9330 shall be delivered in accordance with Table 1 and when
appropriate the heat treatment conditions indicated in Table 2.
5.4.2 By agreement between the purchaser and the manufacturer the tubes may be delivered in a condition
other than the final delivery condition in which case they shall be suitable for subsequent manipulation and the
purchaser shall be informed of any treatment necessary to obtain the specified properties.
4 © ISO 2000 – All rights reserved

Table 1 — Delivery conditions
Delivery condition
Grade
Cold formed Hot formed
As-welded, not heat-treated
PH 23, PH 26, PH 29, PH 35 Welded, normalized on full tube
Welded, heat treatment on full tube
16 Mo 3, 13 CrMo 4-5, 11 CrMo 9-10 Welded, heat treatment on full tube
Table 2 — Heat treatment conditions
Austenitizing Tempering
Reference heat
Cooling Cooling
temperature temperature
Steel grade
a
medium medium
treatment
°C °C
b
PH 23 880-940 Air — —
N
b
PH 26 880-940 Air — —
N
Unalloyed
steels PH 29 880-940 Air — —
b
N
PH 35 880-940 Air — —
b
N
16 Mo 3 N 890-950 Air — —
Alloyed
13 CrMo 4-5 900-960 Air 660-730 Air
N � T
steels
11 CrMo 9-10 900-960 Air 680-750 Air
N � T
a
N = normalizing; N � T = normalizing � tempering.
b
The hot finished tubes may be delivered in the non treated condition at the discretion of the manufacturer provided that the
hot finishing produces a technically equivalent metallurgical condition. The methods of control to ensure equivalence of
structure shall be the subject of a previous agreement between the purchaser and manufacturer.
6 Metallurgical properties
6.1 Chemical composition
6.1.1 Heat analysis
The heat analysis reported by the steel producer shall apply and comply with the requirements given in Table 3.
Table 3 — Chemical composition (heat analysis), % (m/m)
Al
P S
a
Steel grade CSi Mn Cr Mo (total) Others
max. max.
max.
b
PH 23 u 0,17 0,10-0,30 0,30-0,80 0,035 0,03 — — —
b
PH 26 u 0,21 0,10-0,35 0,40-1,20 0,035 0,03 — — —
Unalloyed
steels b
PH 29 u 0,22 0,10-0,40 0,65-1,40 0,035 0,03 — — —
c c b, d
PH 35 u 0,22 0,15-0,55 1,00-1,50 0,035 0,03 — — —
e b
16 Mo 3 0,12-0,20 0,15-0,35 0,40-0,80 0,035 0,03 — 0,25-0,35 0,02
Alloyed
e b
13 CrMo 4-5 0,10-0,17 0,15-0,35 0,40-0,70 0,035 0,03 0,7-1,1 0,40-0,60 0,02
steels
b
11 CrMo 9-10 0,08-0,15 0,15-0,40 0,30-0,70 0,035 0,03 2,0-2,5 0,90-1,20 0,02
NOTE Elements not included in this table should not be intentionally added without the agreement of the purchaser except for elements
which may be added for deoxidation and finishing of the heat. All reasonable precautions should be taken to prevent the addition of elements
from scrap or other materials used in the manufacture, but residual elements may be present provided that the mechanical properties and
applicability are not adversely affected. If the amount of residual elements is likely to affect the weldability of the steel, the content of such
elements (heat analysis) should be stated in the documents mentioned in clause 14.
a
Classification in accordance with ISO 4948-1; designation in accordance with ISO/TR 4949.
b
A maximum copper content of 0,25 % (m/m) may be requested by the purchaser in order to facilitate subsequent forming operations.
c
For tubes with wall thickness � 30 mm the upper limit of the carbon content may be increased by 0,02 % but (C + Mn/6) shall never
exceed 0,47 % (m/m).
d
At the discretion of the manufacturer additions of niobium, titanium and vanadium are permitted up to levels permitted for the non-alloyed
steels listed in ISO 4948-1:1982, unless otherwise agreed upon between the purchaser and the manufacturer. In such a case the test
certificate shall state the level of these elements.
e
For tubes with wall thickness � 30 mm the upper limit of the carbon content may be increased by 0,02 % (m/m).
6 © ISO 2000 – All rights reserved

6.1.2 Product analysis
If a product analysis is required (see 10.1.3), the permissible deviations given in Table 4 shall apply to the heat
analysis specified in Table 3.
The deviations, other than when maxima only are specified, apply either above or below the specified limits of the
range but not both above and below for the same element from different sample products from the same heat.
When maxima only are specified, the deviations are positive only.
Table 4 — Permitted deviations from the specified chemical composition limits given in Table 3
Content specified for the Permissible deviation
Element heat analysis
%(m/m) %(m/m)
C u 0,22
� 0,03
Si u 0,55
� 0,05
Mn
u 1,50 � 0,10
P
u 0,035 � 0,005
S u 0,030 � 0,005
Cr u 2,50 � 0,10
u 0,35
� 0,04
Mo
� 0,30u 1,20 � 0,05
Al u 0,020 � 0,005
6.2 Mechanical properties
6.2.1 At room temperature
The mechanical and technological properties of the tubes covered by this part of ISO 9330, measured at room
temperature (23 °C � 5 °C, see ISO 3205), to be obtained on test pieces selected, prepared and tested in
accordance with clause 9, shall comply with the requirements of Table 5.
Table 5 — Mechanical properties at room temperature
Tensile test Bend test Impact
test
b
R or R or R min. for
Tensile Elongation
eH p0,2 t0,5
a
strength
wall thickness Diameter
A min.
Steel grade Transverse
of the
c
mandrel
R
� 16 mm � 40 mm lt
� 16 mm
m
u 40 mm u 60 mm
2 2
N/mm N/mm %mm J
PH 23 360-480 235 225 215 25 23 3T 27
PH 26 410-530 265 255 245 21 19 4T 27
Unalloyed
steels
PH 29 460-580 290 280 270 23 21 4T 27
PH 35 510-640 355 335 315 19 17 4T 27
d e
16 Mo 31 450-600 270 270 260 22 20 4T 27
Alloyed
d
4T
3CrMo4-5 440-590 290 290 280 22 20 27
steels
11 CrMo 9-10 480-630 280 280 280 20 18 4T 27
a
For wall thicknesses � 60 mm, the values to be obtained shall be the subject of agreement between the purchaser and the manufacturer
at the time of ordering.
b
l = longitudinal; t = transversal.
c
Applicable for wall thicknesses � 30 mm, unless otherwise indicated.
d 2
For wall thicknessesu 10 mm the minimum value of yield strength may be increased by I0 N/mm .
e
Applicable for wall thicknesses � 10 mm.
8 © ISO 2000 – All rights reserved

6.2.2 At elevated temperature
6.2.2.1 Proof stress
The minimum proof stress R values at elevated temperatures are indicated in Table 6.
p0,2
Table 6 — Minimum 0,2 % proof stress (R )valuesatelevatedtemperature
p0,2
R
P0,2
N/mm
Steel
Wall
a
grade
thickness
Temperature
°C
150 200 250 300 350 400 450 500 550 600
u 16
185 165 145 127 116 110 106 —— —
PH 23
� 16u 40
183 16.4 145 127 116 110 106 —— —
� 40u 60
172 159 145 127 116 110 106 —— —
u 16
216 194 171 152 141 134 130 —— —
Un-
PH 26
� 16u 40
213 192 171 152 141 134 130 —— —
alloyed
steels
� 40u 60
204 lea 171 152 141 134 130 —— —
u 16
247 223 198 177 167 158 153 —— —
PH 29
� 16u 40 242 220 198 177 167 158 153 —— —
� 40u 60
236 217 198 177 167 158 153 —— —
u 60
PH 35 270 255 235 215 200 180 170 —— —
u 60
16Mo3 237 224 206 173 159 155 150 145 ——
Alloyed
u 60
steels 13 CrMo 4-5 230 220 210 183 169 164 161 156 150 145
u 60
11 CrMo 9-10 241 233 224 219 212 207 194 180 160 137
a
Values for wall thicknesses � 50 mm are subject to agreement between the purchaser and the manufacturer.
6.2.2.2 Stress rupture properties
The long term stress rupture property (� ) values at elevated temperatures are indicated in annex A. It is stressed
R
that they are given for information only.
6.3 Weldability
Steels intended for the production of tubes covered by this part of ISO 9330 are generally regarded as being
weldable. However, account should be taken of the fact that the behaviour of the steel during and after welding is
dependent not only on the steel, but also significantly, on the condition of preparing and carrying out the welding.
7 Dimensions, masses and tolerances
7.1 Diameters, wall thicknesses and masses
The outside diameters, wall thicknesses and masses of the tubes covered by this part of ISO 9330 should be
selected from those given in ISO 4200.
By agreement between the purchaser and the manufacturer tubing specified by inside diameter and wall thickness
can be supplied. In such a case the dimensions and the tolerances required should be agreed upon at the time of
enquiry and order.
7.2 Lengths
7.2.1 It shall be stated on the enquiry and order whether the tubes are to be delivered with random lengths,
see 7.2.2, or with exact lengths, see 7.2.3.
7.2.2 If the tubes are to be delivered with random lengths, the length range shall be agreed upon at the time of
inquiry and ordering.
7.2.3 If the tubes are to be delivered with exact lengths, the length tolerances given in 7.3.4 shall apply.
7.3 Tolerances
7.3.1 Tolerances on outside diameter and on wall thickness (excluding the weld)
The outside diameters and the wall thicknesses of the tubes covered by this part of ISO 9330 shall be within the
tolerance limits given in Table 7, see 9.3.2.2.
Within areas where the tube surface has been dressed by mechanical machining (such as grinding), e.g. as a
result of instructions required for the performance of non-destructive testing, it is permissible to exceed the minus
deviation on the outside diameter by a small amount over a length of not more than 1 m, provided that wall
thickness remains within t
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