ISO 9330-5:2000

Welded steel tubes for pressure purposes - Technical delivery conditions - Part 5: Submerged arc-welded unalloyed and alloyed steel tubes with specified low 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 low temperature properties. These tubes are intended for pressure purposes in cases when the material is also used as part of a low temperature piping system. The requirements of appropriate international application standards and relevant national legal regulations shall be taken into account by the user. For pressure-containing equipment International Standard ISO 5730 is 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 5: Tubes soudés à l'arc immergé en aciers non alliés et alliés avec caractéristiques spécifiées à basse température

General Information

• Status: Published
• Publication Date: 28-Jun-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 9330-5:2000 - "Welded steel tubes for pressure purposes - Technical delivery conditions - Part 5" specifies technical delivery conditions for submerged arc‑welded (SAW) welded steel tubes of circular cross‑section made from unalloyed or alloyed steels with specified low temperature properties. It applies where the tube material is used in pressure systems that also form part of low‑temperature piping (e.g., cryogenic or cold service). The standard defines manufacturing, heat treatment, chemical and mechanical property requirements, inspection and testing, marking and documentation for SAW tubes supplied for pressure purposes.

Key topics and technical requirements

• Scope and intended use: SAW tubes for pressure purposes when low‑temperature performance is required; “tube” and “pipe” are synonymous in the standard.
• Manufacturing: Tubes are formed from flat‑rolled products and welded longitudinally or helically. SAW process must include at least one inside and one outside weld run; welding procedures and operators should be qualified. Tubes can be hot‑ or cold‑finished prior to heat treatment.
• Delivery condition / Heat treatment: Tubes are supplied heat‑treated over full length - normalizing, normalizing + tempering, or quenching + tempering depending on grade and agreement between parties.
• Metallurgical requirements: Fully‑killed steels; heat analysis and product analysis requirements for chemical composition are specified (see standard tables). Grain size, deoxidation and residual element considerations are covered.
• Mechanical and low temperature properties: Tensile, impact (Charpy) and bend tests, and requirements for low‑temperature toughness are specified or referenced.
• Inspection & testing: Specifies ultrasonic and radiographic weld seam inspection, tube end and strip/plate laminar testing, hydraulic testing, and acceptance criteria. Inspection documents and test categories follow ISO 10474 and related ISO test methods.
• Purchaser information: Mandatory order data include denomination, dimensional standard reference, OD × wall thickness, length, reference to ISO 9330‑5 and steel grade; optional items include product analysis, weld testing, bevelled ends, marking, coatings and specific inspection levels.

Applications and users

ISO 9330‑5 is aimed at:

• Tube manufacturers and SAW mill operators
• Procurement and specification engineers (oil & gas, petrochemical, LNG, cryogenics, power plants)
• Pressure‑piping designers and fabricators requiring low‑temperature toughness
• Inspectors, testing laboratories and compliance officers verifying mechanical and non‑destructive testing (NDT) results

Using ISO 9330‑5 helps ensure welded steel tubes meet consistent technical delivery conditions for safe, reliable performance in cold and pressure‑containing piping systems.

Related standards

• ISO 404 - General technical delivery requirements
• ISO 4200 - Dimensions and masses for plain end tubes
• ISO 10474 - Inspection documents for steel products
• ISO 9765 / ISO 12096 - Ultrasonic and radiographic testing for SAW weld seams
• ISO 5730 - Pressure‑containing equipment (application guidance)

Keywords: ISO 9330‑5, submerged arc‑welded, SAW tubes, welded steel tubes, low temperature properties, pressure purposes, technical delivery conditions, inspection and testing.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 9330-5
First edition
2000-06-15
Welded steel tubes for pressure
purposes — Technical delivery
conditions —
Part 5:
Submerged arc-welded unalloyed
and alloyed steel tubes with specified
low temperature properties
Tubes en acier soudés pour service sous pression —
Conditions techniques de livraison —
Partie 5: Tubes soudés à l'arc immergé en aciers non alliés et alliés
avec caractéristiques spécifiées à basse température
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
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 9330-5 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
iv © ISO 2000 – All rights reserved

INTERNATIONAL STANDARD ISO 9330-5:2000(E)
Welded steel tubes for pressure purposes — Technical delivery
conditions —
Part 5:
Submerged arc-welded unalloyed and alloyed steel tubes
with specified low 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 low temperature properties. These tubes are intended for
pressure purposes in cases when the material is also used as part of a low temperature piping system.
The requirements of appropriate international application standards and relevant national legal regulations shall be
taken into account by the user. For pressure-containing equipment International Standard ISO 5730 is 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 643:1983, Steels — Micrographic determination of the ferritic or austenitic grain size.
ISO 2566-1:1984, Steel — Conversion of elongation values — Part 1: Carbon and low alloy steels.
ISO 3205:1976, Preferred test temperatures.
ISO 3545-1:1989, Steel tubes and fittings — Symbols for use in specifications — Part 1: Tubes and tubular
accessories with circular cross-section.
1) This International Standard has been withdrawn and replaced by ISO 148-1:—, ISO 148-2:1998 and ISO 148-3:1998.
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.
3.3 Symbols for tests
3.3.1 Tensile test
See ISO 6892.
2 © ISO 2000 – All rights reserved

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 9330-5;
g) steel grade, see Table 1;
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) impact test on the weld and/or heat affected zone, see 10.1.3;
j) specific marking, see 12.3;
k) protective coating, see 13;
l) 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 PL 21 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- PL 21-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.
4 © ISO 2000 – All rights reserved

5.4 Delivery condition
Tubes covered by this part of ISO 9330 shall be supplied heat-treated over their full length. The following heat
treatments shall be used depending on the type of steel, see Table 1.
� normalizing;
� normalizing and tempering;
� quenching and tempering.
Table 1 — Heat treatment conditions
Quenching and tempering temperature
°C
Reference Normalizing Tempering
Steel grade
temperature temperature
heat treatment
Hardening Tempering
(see Table 2) Cooling
a
°C °C
temperature temperature
b
medium
°C °C
PL 21 N 900-940 —— — —
PL 23 N 890-930 —— — —
Unalloyed
water or
steels
PL 25 Q+T —— 890-930 600-680
oil
PL 26 N 890-930 —— — —
c
11 MnNi 5-3 890-940 580-640 —— —
N
c
13 MnNi 6-3 890-940 580-640 —— —
N
water or
d
12 Ni 14 830-880 580-640 820-880 580-660
Q+T
Alloyed
oil
steels
water or
d
X12Ni 5 800-850 580-640 800-850
Q+T 580-660
oil
water or
X10 Ni 9 Q+T 880-930 — 770-820 540-600
oil
a
N = normalizing; Q � T = quenching� tempering.
b
When choosing the cooling medium the influence of other parameters, such as dimensions and quenching
temperature, on properties and crack susceptibility shall be taken into account. Other cooling media such as synthetic
quenchants may also be used.
c
Tempering can occasionally be necessary after normalizing. In such a case the manufacturer shall inform the
purchaser accordingly and shall state the tempering temperature as well.
d
If the product’s dimensions so permit, normalizing (with subsequent tempering if necessary) may be carried out at the
manufacturer’s discretion instead of quenching and tempering. In such a case the manufacturer shall inform the
purchaser accordingly.
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 2.
Table 2 — Chemical composition (heat analysis), % (m/m)
CSI Mn P S Al Mo Ni V Nb
a
Steel grade
max. max. max. max. (total) min. max. max. max.
b
PL 21 0,17 0,35 0,40-1,00 0,030 0,025 —— — —
0,015
b
PL 23 0,19 0,35 0,60-1,20 0,030 0,025 —— — —
Unalloyed 0,015
b
steel
PL 25 0,17 0,35 0,40-1,00 0,030 0,025 —— — —
0,015
b
PL 26 0,20 0,35 0,80-1,40 0,030 0,025 —— — —
0,015
c d
11 MnNi5-3 0,14 0,50 0,70-1,50 0,030 0,025 — 0,05 0,05
0,020 0,3 -0,8
c d
13 MnNi6-3 0,18 0,50 0,85-1,65 0,030 0,025 — 0,05 0,05
0,020 0,3 -0,8
Alloyed
12 Ni 14 0,15 0,35 0,3-0,8 0,025 0,020 0,020 — 3,25-3,75 0,05 —
steel
X 12 Ni 5 0,15 0,35 0,3-0,8 0,025 0,020 0,020 — 4,5-5,3 0,05 —
X 10 Ni 9 0,13 0,35 0,3-0,8 0,025 0,020 0,020 010 8,5-9,5 0,05
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
Metallic aluminium content. Where the total aluminium content is determined, the results shall be deemed to meet the
requirement provided the total aluminium content value obtained is not less than 0,018 % (m/m). In case of dispute, the
metallic aluminium content shall be determined. Alternatively, an austenitic grain size of 6 or finer, determined in accordance
with ISO 643, can be agreed upon. By agreement between the interested parties, aluminium may be replaced by other
elements having a similar effect.
c
Total aluminium content. By agreement between the interested parties, aluminium may be replaced by other elements
having a similar effect.
d
The lower limit value for the nickel content may be reduced to not less than 0,15 % (m/m) for tubes with wall thickness
u 10 mm.
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 3 shall apply to the heat
analysis specified in Table 2.
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 3 — Permitted deviations from the specified chemical composition limits given in Table 2
Content specified for the
heat analysis
Element Permissible deviation
%(m/m)
C u 0,20
� 0,05
Si u 0,50 � 0,05
Mn u 1,65 � 0,10
P u 0,030 � 0,005
S u 0,025 � 0,005
Al – 0,005
W 0,020
Mo
u 0,10 � 0,04
u 0,85 � 0,05
� 0,85u 3,75 � 0,07
Ni
� 3,75u 5,30 � 0,10
� 5,30u 9,50 � 0,15
V u 0,05
� 0,01
Nb u 0,05
� 0,01
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 4.
Table 4 — Mechanical properties at room temperature
Tensile test Bend test
Reference
R or R or R for wall
heat eH p0,2 t0,5 Elongation
Tensile
Diameter
b
treatment
thicknesses
Steel grade strength for wall thickness
of the
mandrel
� 13 mm � 25 mm
a b
R
u 40 mm
u 13 mm
m
u 25 mm u 40 mm
2 2
N/mm N/mm %Mm
c
PL21 N 360-480 215 215 24 4T
c 4T
PL23 N 410-530 235 235 22
Unalloyed
steels
PL25 N 360-490 255 255 235 21 4T
c 4T
PL26 N 480-580 265 275 21
11MnNi5-3 N 410-530 285 275 265 22 4T
13MnNi 6-3 N 490-610 355 345 335 20 4T
Alloyed
12 Ni 14 Q+ T 440-590 245 245 245 16 7T
steels
X 12Ni 5 Q+ T 510-710 390 390 380 17 7T
X1ONi 9 Q+ T 690-840 510 510 510 15 7T
a
N = normalizing; Q + T = quenching � tempering, see 8.3.
b
For wall thicknesses � 40 mm the values to be obtained shall be the subject of agreement between the purchaser and the manufacturer at
the time of ordering.
c
To be agreed at the time of ordering.
8 © ISO 2000 – All rights reserved

6.2.2 At low temperature
Table 5 gives minimum values for the impact energy, as determined on ISO V-notch test pieces, used to
characterize the cold-toughness of the various steel grades at low temperature (see also footnote b to Table 5).
Impact tests shall be carried out only at the lowest temperature indicated in Table 5 for each steel grade
(see also 10.1.3).
Table 5 — Impact properties at low temperature
b
Minimum impact test value
Wall
a
Av
Orientation
thickness
of test J
T
Steel grade pieces with
Temperature
mm
respect to
°C
tube axis
� 20
� 196 � 120 � 110 � 100 � 90 � 60 � 50 � 40 � 20
PL 21 u 10 ———— — — — 40 45 55
Longitudinal
Longitudinal ———— — — 27 40 45 50
u 25
PL 23
Transverse ———— — — 27 30 35
Longitudinal ———— — — 40 45 50 60
u 25
Unalloyed
Transverse ———— — — 27 30 35 40
steels
PL 25
Longitudinal ———— — — — 40 45 55
� 25u 40
Transverse ———— — — — 27 30 35
Longitudinal ———— — — 27 40 45 50
u 25
PL 26
Transverse ———— — — — 27 30 35
11 MnNi 3-4 Longitudinal ———— — 40 45 50 55 70
u 40
11 MnNi 6-3 Transverse ———— — 27 30 35 40 45
Longitudinal ——— 40 45 50 55 55 60 65
u 25
Transverse ——— 27 30 35 35 40 45 45
12 Ni 14
Longitudinal ———— 40 45 50 50 55 65
� 25u 40
Transverse ———— 27 30 30 35 40 45
Alloyed
steels
Longitudinal — 40 45 50 55 65 65 65 70 70
u 25
Transverse — 27 30 30 35 45 45 45 50 50
X12 Ni 5
Longitudinal —— 40 45 50 60 65 65 65 70
� 25u 40
Transverse —— 27 30 30 40 45 45 45 50
Longitudinal 40 50 50 60 60 70 70 70 70 70
u 40
X10 Ni 9
Transverse 27353540 40 50 50 50 50 50
a
The values for tubes with wall thickness exceeding the maximum value shown in the table shall be agreed at the time of enquiry and order.
b
Average of three test pieces. Single values not less than 70 % of the average value. The values apply to standard 10 mm � 10 mm test
pieces. For different sizes of test pieces, see 11.5.
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.
...