EN ISO 13703:2000

SLOVENSKI STANDARD
01-junij-2001
Petroleum and natural gas industries - Design and installation of piping systems
on offshore production platforms (ISO 13703:2000)
Petroleum and natural gas industries - Design and installation of piping systems on
offshore production platforms (ISO 13703:2000)
Erdöl- und Erdgasindustrien - Auslegung und Verlegung von Rohrleitungssystemen auf
Offshore-Förderplattformen (ISO 13703:2000)
Industries du pétrole et du gaz naturel - Conception et installation de systemes de
tuyauterie sur les plates-formes de production en mer (ISO 13703:2000)
Ta slovenski standard je istoveten z: EN ISO 13703:2000
ICS:
75.180.10 Oprema za raziskovanje in Exploratory and extraction
odkopavanje equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 13703
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2000
ICS 75.180.10
English version
Petroleum and natural gas industries - Design and installation of
piping systems on offshore production platforms (ISO
13703:2000)
Industries du pétrole et du gaz naturel - Conception et Erdöl- und Erdgasindustrien - Auslegung und Verlegung
installation de systèmes de tuyauterie sur les plates-formes von Rohrleitungssystemen auf Offshore-Förderplattformen
de production en mer (ISO 13703:2000) (ISO 13703:2000)
This European Standard was approved by CEN on 9 December 2000.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2000 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13703:2000 E
worldwide for CEN national Members.

Page 2
CORRECTED  2002-07-24
Foreword
This document (ISO 13703:2000) has been prepared by Technical Committee ISO/TC 67
"Materials, equipment and offshore structures for petroleum and natural gas industries" in
collaboration with Technical Committee CEN/TC 12 "Materials, equipment and offshore
structures for petroleum and natural gas industries", the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of
an identical text or by endorsement, at the latest by June 2001, and conflicting national
standards shall be withdrawn at the latest by June 2001.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of the International Standard ISO 13703:2000 has been approved by CEN as a
European Standard without any modifications.

INTERNATIONAL ISO
STANDARD 13703
First edition
2000-12-15
Petroleum and natural gas industries —
Design and installation of piping systems
on offshore production platforms
Industries du pétrole et du gaz naturel — Conception et installation de
systèmes de tuyauterie sur les plates-formes de production en mer
Reference number
ISO 13703:2000(E)
©
ISO 2000
ISO 13703:2000(E)
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ii © ISO 2000 – All rights reserved

ISO 13703:2000(E)
Contents Page
Foreword.v
Introduction.vi
1 Scope .1
2 Normative references .1
3 Terms, definitions, symbols and abbreviated terms.2
3.1 Terms and definitions .2
3.2 Symbols and abbreviated terms .4
4 General considerations.6
4.1 Materials .6
4.2 Code of pressure piping .7
4.3 Demarcation between systems with different pressure ratings.7
4.4 Corrosion considerations .9
5 Piping design .10
5.1 Pipe material grades.10
5.2 Sizing criteria — General .12
5.3 Sizing methods for liquid lines.12
5.4 Sizing criteria for single-phase gas lines.19
5.5 Sizing criteria for gas/liquid two-phase lines .23
5.6 Pipe wall thicknesses.26
5.7 Joint connections .30
5.8 Expansion and flexibility.31
5.9 Start-up provisions.32
6 Selection of valves .32
6.1 General.32
6.2 Types of valves .33
6.3 Fire resistance of valves .35
6.4 Valve sizing .35
6.5 Valve pressure and temperature ratings.36
6.6 Valve materials.37
7 Fittings and flanges.37
7.1 General.37
7.2 Welded fittings .38
7.3 Screwed fittings .38
7.4 Branch connections .38
7.5 Flanges .39
7.6 Proprietary connectors .41
7.7 Special requirements for sulfide stress-cracking service.41
7.8 Erosion prevention .41
8 Design considerations for particular piping systems.41
8.1 General.41
8.2 Wellhead accessory items .41
8.3 Flowline and flowline accessories.42
8.4 Production manifolds.45
8.5 Process vessel piping .45
8.6 Utility systems.47
8.7 Heating fluid and glycol systems.48
8.8 Pressure relief and disposal systems .48
8.9 Drain systems .50
ISO 13703:2000(E)
8.10 Bridge piping between platforms.50
8.11 Risers .50
8.12 Sampling valves.51
9 Considerations of related items .51
9.1 General.51
9.2 Layout .51
9.3 Elevations .51
9.4 Piping supports.51
9.5 Other corrosion considerations .51
9.6 Thermal insulation .54
9.7 Noise .56
9.8 Pipe, valves and fittings tables.56
9.9 Inspection, maintenance, repair and modification.56
10 Installation and quality control.56
10.1 General.56
10.2 Welding .56
10.3 Pressure testing.57
10.4 Test record.58
Annex A (informative) Example problems .59
Annex B (informative) Examples of pipe, valves and fittings tables.71
Annex C (informative) Acceptable butt-welded joint design for unequal wall thicknesses .74
Bibliography .76
iv © ISO 2000 – All rights reserved

ISO 13703:2000(E)
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 International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 13703 was prepared by Technical Committee ISO/TC 67, Materials, equipment and
offshore structures for petroleum and natural gas industries, Subcommittee SC 6, Processing equipment and
systems.
Annexes A, B and C of this International Standard are for information only.
ISO 13703:2000(E)
Introduction
th
This International Standard is based on API RP 14E, 5 edition, October 1991.
vi © ISO 2000 – All rights reserved

INTERNATIONAL STANDARD ISO 13703:2000(E)
Petroleum and natural gas industries — Design and installation of
piping systems on offshore production platforms
1 Scope
This International Standard specifies minimum requirements and gives guidance for the design and installation of
new piping systems on production platforms located offshore for the petroleum and natural gas industries. It covers
piping systems up to 69 000 kPa (ga) maximum, within temperature range limits for the materials meeting the
requirements of ASME B31.3.
NOTE For applications outside these pressure and temperature ranges, this International Standard may be used but
special consideration should be given to material properties.
Annex A gives some worked examples for solving piping design problems.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard 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.
ISO 13623, Petroleum and natural gas industries — Pipeline transportation systems.
1)
API RP 520-2 , Recommended practice for design and installation of pressure-relieving systems in refineries —
Part 2.
2)
ASME , Boiler and pressure vessel code: Section VIII: Pressure vessels, Division 1.
ASME B 31.3, Process piping.
3)
NACE MR0175 , Sulfide stress cracking resistant metallic materials for oil field equipment.
NACE TM0177, Laboratory testing of metals for resistance to specific forms of environmental cracking in H S
environments.
NACE TM0284, Evaluation of pipeline and pressure vessel steels for resistance to hydrogen-induced cracking.
1) American Petroleum Institute, 1220 L Street, N.W., Washington, DC 20005-4070, U.S.A.
th
2) American Society of Mechanical Engineers, 345 East 47 Street, New York, N.Y. 10017, U.S.A.
3) National Association of Corrosion Engineers, P.O. Box 218340, Houston, Texas 77218-8340, U.S.A.
ISO 13703:2000(E)
3 Terms, definitions, symbols and abbreviated terms
For the purposes of this International Standard, the following terms, definitions, symbols and abbreviated terms
apply.
3.1 Terms and definitions
3.1.1
chloride stress-corrosion cracking service
service in which the process stream contains water and chlorides in a sufficient concentration, and at a high
enough temperature, to induce stress-corrosion cracking of susceptible materials
NOTE Other constituents present, such as oxygen (O ), may contribute to such chloride stress-corrosion cracking.
3.1.2
choke
device specifically intended to restrict the flow rate of fluids
3.1.3
corrosion-erosion
eroding away of a protective film of corrosion product by the action of the process stream, exposing fresh metal
which then corrodes
NOTE Extremely high metal mass loss can occur under these conditions.
3.1.4
corrosive gas
gas which, when dissolved in water or other liquid, causes corrosion of metal
NOTE Corrosive gases usually contain hydrogen sulfide (H S), carbon dioxide (CO ) and/or oxygen (O ).
2 2 2
3.1.5
corrosive hydrocarbon service
service in which the process stream contains water or brine and carbon dioxide (CO ), hydrogen sulfide (H S),
2 2
oxygen (O ) or other corrosive agents under conditions which cause corrosion of metal
3.1.6
expansion bellows
corrugated piping device designed to absorb expansion and contraction
3.1.7
expansion bend
piping configuration designed to absorb expansion and contraction
3.1.8
flowline
piping that carries well fluid from wellhead to manifold or first process vessel
3.1.9
flow regime
flow condition of a multi-phase process stream
EXAMPLES Slug flow, mist flow or stratified flow.
3.1.10
fluid
gas, vapour, liquid or combinations thereof
2 © ISO 2000 – All rights reserved

ISO 13703:2000(E)
3.1.11
header
part of a manifold that directs fluid to a specific process system
See Figures 5 and 6.
3.1.12
hydrocarbon wettability
ability of the process stream to form a protective hydrocarbon film on metal surfaces
3.1.13
manifold
assembly of pipe, valves and fittings by which fluid from one or more sources is selectively directed to various
process systems
3.1.14
nipple
section of threaded or socket-welded pipe, shorter than 300 mm, used as an appurtenance
3.1.15
nominal pipe size
nominal size
NPS
DN
designation of size in inches which is common to all components in a piping system other than those components
designated by outside diameter
NOTE Nominal pipe size is designated by the letters NPS (when relating to inches) or DN (when relating to millimetres)
followed by a number; it is a convenient number for reference purposes and it is normally only loosely related to manufacturing
dimensions.
3.1.16
non-corrosive hydrocarbon service
service in which the process stream conditions do not cause significant metal mass loss, selective attack, chloride
stress-corrosion cracking or sulfide stress-cracking
3.1.17
normal conditions
absolute pressure of 101,325 kPa and temperature of 0 °C
3.1.18
platform piping
any piping intended to contain or transport fluid on a platform
3.1.19
pressure rating
number relating to the pressure for which a system is suitable
NOTE The number may relate directly to the rated working pressure (e.g. ISO 10423 [1] pressure rating 13,8 MPa and API
pressure rating 2 000 psi) or may have a more indirect correlation (e.g. ASME class 300).
3.1.20
pressure sensor
device designed to detect a predetermined pressure
3.1.21
process component
single functional piece of production equipment and associated piping
EXAMPLES Pressure vessel, heater, pump, etc.
ISO 13703:2000(E)
3.1.22
riser
vertical portion of a pipeline (including the bottom bend) arriving on or departing from a platform
3.1.23
shutdown valve
automatically-operated valve used for isolating a process component or process system
3.1.24
sulfide stress-cracking service
service in which the process stream contains water or brine and contains a sufficient concentration of hydrogen
sulfide (H S) to induce sulfide stress-cracking of susceptible materials
3.1.25
wellhead pressure
maximum shut-in surface pressure that may exist in a well
3.2 Symbols and abbreviated terms
3.2.1 Symbols
A minimum pipe cross-sectional flow area required per unit volume flowrate, expressed in square
2 3
millimetres per cubic metre per hour (mm /m /h)
B mean coefficient of thermal expansion at operating temperatures normally encountered, expressed in
millimetres per kelvin (mm/K)
C empirical constant, dimensionless
C sum of corrosion, mechanical strength and thread allowance, expressed in millimetres (mm)
e
C valve coefficient, dimensionless
v
NOTE 1 This value is equal to the water flowrate in US gpm at 60 °F required to generate a pressure drop of 1 psi
(US Customary units only are used in this instance to maintain alignment with other published data).
D pipe inside diameter, expressed in metres (m)
i
D pipe outside diameter, expressed in millimetres (mm)
o
d pipe inside diameter, expressed in millimetres (mm)
i
d gas relative density (air = 1), dimensionless
g
d liquid relative density (water = 1), dimensionless
L
E longitudinal weld joint factor, dimensionless
E modulus of elasticity of piping material in the cold condition, expressed in newtons per square millimetre
m
(N/mm )
f Moody friction factor, dimensionless
g gravitational constant, expressed in metres per second per second (m/s )
h acceleration head, expressed in metres (m) of liquid
a
h friction head, expressed in metres (m) of liquid
f
4 © ISO 2000 – All rights reserved

ISO 13703:2000(E)
h absolute pressure head, expressed in metres (m) of liquid
p
h static head, expressed in metres (m) of liquid
st
h velocity head, expressed in metres (m) of liquid
vh
h absolute vapour pressure, expressed in metres (m) of liquid
vpa
h pressure loss, expressed in kilopascals (kPa)
W
K acceleration factor, dimensionless
L developed pipe length, expressed in metres (m)
L pipe length, expressed in kilometres (km)
m
m manufacturing wall thickness tolerance, expressed as a percentage (%)
NPSH available net positive suction head, expressed in metres (m) of liquid
a
p operating pressure, expressed in kilopascals [kPa (abs)]
NOTE 2 Also denoted in text as “flowing pressure”.
p internal design pressure, expressed in kilopascals [kPa (ga)]
i
q gas flow rate, expressed in cubic metres per hour (m /h) at normal conditions
g
q liquid flow rate, expressed in cubic metres per hour (m /h)
L
q total liquid plus vapour mass flowrate, expressed in kilograms per hour (kg/h)
m
R gas/liquid volume ratio, dimensionless
Re Reynolds number, dimensionless
R pump speed, expressed in revolutions per minute (r/min)
p
S allowable stress, expressed in newtons per square millimetre (N/mm )
T operating temperature, expressed in kelvin (K)
NOTE 3 Also denoted in text as “flowing temperature”.
t pressure design thickness, expressed in millimetres (mm)
t minimum nominal pipe wall thickness, expressed in millimetres (mm)
nom
U anchor distance (straight line distance between anchors), expressed in metres (m)
v fluid erosional velocity, expressed in metres per second (m/s)
e
v average gas velocity, expressed in metres per second (m/s)
g
NOTE 4 Also denoted in text as “gas velocity”
v average liquid velocity, expressed in metres per second (m/s)
L
y resultant of total displacement strains, expressed in millimetres (mm)
ISO 13703:2000(E)
Y temperature factor, dimensionless
Z gas compressibility factor, dimensionless
�L expansion to be absorbed by pipe, expressed in millimetres (mm)
�p pressure drop, expressed in kilopascals (kPa)
� gas density at operating pressure and temperature, expressed in kilograms per cubic metre (kg/m )
g
� liquid density at operating temperature, expressed in kilogram per cubic metre (kg/m )
L
� gas/liquid mixture density at operating pressure and temperature, expressed in kilograms per cubic metre
m
(kg/m )
�T temperature change, expressed in kelvin (K)
� gas viscosity at flowing pressure and temperature, expressed in pascal seconds (Pa�s)
g
� liquid viscosity, expressed in pascal seconds (Pa�s)
L
3.2.2 Abbreviated terms
ERW Electric Resistance Weld
PWHT Post-Weld Heat Treatment
RF Raised Face
RTJ Ring Type Joint
SAW Submerged Arc Weld
SMYS Specified Minimum Yield Strength
4 General considerations
4.1 Materials
Carbon steel materials are suitable for many of the piping systems on production platforms, although stainless steels
and other materials are also widely used. The following should be considered when selecting piping materials:
a) type of service;
b) compatibility with other materials;
c) mechanical strength, ductility, elasticity and toughness;
d) need for special welding procedures, or other jointing techniques;
e) need for special inspections, tests, or quality control;
f) possible misapplication in the field;
g) corrosion and erosion caused by internal fluids and/or marine environments;
h) need for performance in a fire situation.
6 © ISO 2000 – All rights reserved

ISO 13703:2000(E)
4.2 Code of pressure piping
4.2.1 The design and installation of platform piping shall be in accordance with ASME B31.3, as modified by this
International Standard. Risers for which ASME B31.3 is not applicable should be designed and installed in
accordance with 4.2.2 to 4.2.6.
4.2.2 Design, construction, inspection and testing of risers shall be in accordance with ISO 13623 and
governmental rules and regulations as appropriate to the application, using a design stress no greater than
0,6 times SMYS. Pipeline design codes may be used from pig trap to pig trap, except where precluded by national
regulations.
4.2.3 One hundred percent radiography of welding should be performed on riser piping. The non-destructive
testing of platform piping complying with ASME B31.3 should as a minimum satisfy Table 10 of this International
Standard.
4.2.4 Impact tests shall be performed as specified by ASME B31.3. The design of high-pressure piping systems
(i.e. above ASME class 2500) needs special consideration and shall be in accordance with the high-pressure piping
requirements of ASME B31.3.
4.2.5 Valves, fittings and flanges should be manufactured in conformance with International and/or National
Standards. Pressure/temperature ratings and material compatibility should be verified.
4.2.6 In determining the transition between risers and platform piping to which these practices apply, the first
incoming and last outgoing valve that block pipeline flow are the limits of this International Standard’s application,
except for riser wall thickness calculations and material selection which may be to a pipeline code to permit a
constant bore for pigging. Recommended practices included in this International Standard may be utilized for riser
design when factors such as water depth, batter of platforms legs, potential bubbling area etc. are considered.
National regulations may require the pipeline code to be continued to/from the pig launcher/receiver.
4.2.7 It is also common practice for a pipeline code to apply through the riser up to the pig trap and to include the
piping and the first valve on each branch on the riser/pipeline.
4.3 Demarcation between systems with different pressure ratings
4.3.1 Normally, after the well-stream leaves the wellhead the pressure is reduced in stages.
After the pressure is reduced, process components of lower pressure ratings may be used. A typical example is
shown inFigure1.
4.3.2 A pressure-containing process component shall either be designed to withstand the maximum internal
pressure which can be exerted on it under any conditions, or shall be protected by a pressure-relieving device. In
this case, a pressure-relieving device means a safety relief valve or a rupture disc. In general, when determining if
pressure-relieving devices are needed, high-pressure shutdown valves, check valves, control valves or other such
devices should not be considered as preventing overpressure of process components.
4.3.3 Pressure-rating boundaries shall be indicated on piping and instrument diagrams. Each system component
(vessels, flanges, pipe or accessories) shall be designed to withstand the highest pressure to which it could be
subjected under any foreseeable conditions, or it shall be protected by a pressure-relieving device. Abnormal
pressure conditions shall be considered, e.g. start-up, shutdown, surge, etc.
ISO 13703:2000(E)
NOTE 1 Design temperature is 65 °C throughout.
NOTE 2 Required shutdown sensors are not shown.
NOTE 3 Flowline and manifold are designed for wellhead pressure.
NOTE 4 System design pressures may be limited by factors other than the flange and valve pressure classifications (i.e. pipe
wall thickness, separator design pressure, etc.).
NOTE 5 Only where spare relief valves are installed may upstream isolation valves be installed, and then it is essential that
all isolation valves are interlocked to ensure that the pressurized system is protected at all times.
Key
1 Upper master gate valve 6 Shutdown valve 11 Level controller
2 Wellhead 7 To other systems 12 Medium pressure separator
3 Wing choke 8 Pressure safety valve 13 Low pressure separator
4 Flow tee 9 High pressure separator 14 Treating, storage or sales
5 Manifold 10 Gas outlet
Figure 1 — Example of a process system, denoting flange and valve pressure-rating changes
8 © ISO 2000 – All rights reserved

ISO 13703:2000(E)
4.4 Corrosion considerations
4.4.1 General
Detailed corrosion-control practices for platform piping systems are outside the scope of this International
Standard. Such practices should, in general, be developed by corrosion control specialists. Platform piping systems
should, however, be designed to accommodate and be compatible with the corrosion control practices described
below. Recommendations for corrosion-resistant materials and mitigation practices are given in the appropriate
clauses of this International Standard.
The corrosivity of process streams may change over time. The possibility of changing conditions should be
considered at the design stage.
4.4.2 Mass loss corrosion
Carbon steel platform piping systems may corrode under some process conditions. Production process streams
containing water, brine, carbon dioxide (CO ), hydrogen sulfide (H S) or oxygen (O ), or combinations of these,
2 2 2
may be corrosive to metals used in system components. The type of attack (uniform metal loss, pitting,
corrosion-erosion, etc.) as well as the specific corrosion rate can vary in the same system, and can vary over time.
The corrosivity of a process stream is a complex function of many variables, including:
a) hydrocarbon, water, salt and corrosive gas content;
b) hydrocarbon wettability;
c) flow velocity, flow regime and piping configuration;
d) temperature, pressure and pH;
e) solids content (sand, mud, bacterial slime and microorganisms, corrosion products, and scale).
Corrosivity predictions are very qualitative and may be unique for each system. Some corrosivity information for
corrosive gases found in production streams is shown in Table 1.
Table 1 is intended only as a general guide for corrosion mitigation considerations and not for specific corrosivity
predictions. Corrosion inhibition is an effective mitigation procedure when corrosive conditions are predicted or
anticipated (see 5.1.2).
Table 1 — Qualitative guideline for mass loss corrosion of steel
Limiting values in brine
a
Corrosive gas Solubility ratio Non-corrosive ratio Corrosive ratio
–6 –6 –6
���� 10 ���� 10 ���� 10
Oxygen (O ) 8 <0,005 >0,025
Carbon dioxide (CO ) 1 700 < 600 > 1 200
Hydrogen sulfide (H S) 3 900 See Note See Note
NOTE No limiting values for mass loss corrosion by hydrogen sulfide are shown in this table because
the amount of carbon dioxide and/or oxygen greatly influences the metal loss corrosion rate. Hydrogen sulfide
alone is usually less corrosive than carbon dioxide due to the formation of an insoluble iron sulfide film which
tends to reduce metal mass loss corrosion.
a
Solubility ratio by volume. Solubility at 20 °C in distilled water at 1 atm partial pressure. Oxygen (O )is
for 1 atm air pressure. Source: [3].
ISO 13703:2000(E)
4.4.3 Chloride stress-corrosion cracking
Careful consideration shall be given to the effect of stress and chlorides, if alloy and stainless steels are selected to
prevent corrosion by hydrogen sulfide and/or carbon dioxide. Process streams that contain water with chlorides
may cause cracking in susceptible materials, especially if oxygen is present and the temperature is above 60 °C.
High alloy and stainless steels, such as the AISI 300-series austenitic stainless steels, precipitation-hardening
stainless steels, and “A-286” (ASTM A 453 [2] grade 660), should not be used unless their suitability in the
proposed environment has been adequately demonstrated. Consideration should also be given to the possibility
that chlorides may be concentrated in localized areas in the system.
4.4.4 Sulfide stress-cracking
Process streams containing water and hydrogen sulfide may cause sulfide stress-cracking of susceptible materials.
This phenomenon is effected by a complex interaction of parameters including metal chemical composition,
hardness and microstructure, heat treatment condition and factors such as pH, hydrogen sulfide concentration,
stress and temperature. Materials used for process streams containing hydrogen sulfide should be selected to
accommodate these parameters.
Testing of these materials should be in accordance with NACE TM0177.
4.4.5 Application of NACE MR0175
Materials selected for resistance to sulfide stress-cracking should be in accordance with NACE MR0175.
Corrosion-resistant alloys not listed in NACE MR0175 may exhibit such resistance and may be used if it can be
demonstrated that they are resistant in the proposed environment of use (or in an equivalent laboratory
environment). Caution should be exercised in the use of materials listed in NACE MR0175. The materials listed may
be resistant to sulfide stress-cracking, but may not be suitable for use in chloride stress-corrosion cracking service.
4.4.6 Hydrogen-induced cracking
Process streams containing water and hydrogen sulfide may cause hydrogen-induced cracking (HIC) of susceptible
materials, particularly to carbon steel plate fabrications or pipe made from plate. Consideration shall be given to
HIC-testing such materials, which should be in accordance with NACE TM0284. Specialist advice should be sought
in this area.
5 Piping design
5.1 Pipe material grades
5.1.1 Non-corrosive hydrocarbon service
The two most commonly used material grades of carbon steel pipe are ASTM A 106 [4] grade B, API 5L [5] grade B
and ISO 3183-1 [6]. Seamless pipe is generally preferred due to its consistent quality. ASTM A 106 is only
manufactured in seamless, while API 5L is available in seamless, ERW and SAW. If use of grade B requires
excessive wall thickness, use of pipe with higher allowable design stress such as API 5L grade X52, may be
required; however, special welding procedures and close supervision are necessary when using API 5L grade X46
or higher. It should be noted that the use of high yield materials such as 5L X-grades, will not result in a
proportional increase in allowable stress values when used in accordance with ASME B31.3.
Many of the grades of pipe listed in ASME B31.3 are suitable for non-corrosive hydrocarbon service. The following
types or grades of pipe are specifically excluded from hydrocarbon service in accordance with ASME B31.3:
a) furnace lap-welded and furnace butt-welded;
b) fusion-welded per ASTM A 134 [7] and ASTM A 139 [8];
c) spiral-welded, except API 5L spiral-welded.
10 © ISO 2000 – All rights reserved

ISO 13703:2000(E)
5.1.2 Corrosive hydrocarbon service
Design for corrosive hydrocarbon service should provide for one or more of the following corrosion-mitigating
practices:
a) chemical treatment;
b) corrosion-resistant alloys;
c) protective coatings (see 9.5.2).
Of these, chemical treatment of the fluid in contact with carbon steels has been common practice.
Corrosion-resistant alloys that have proven successful in similar applications (or by suitable laboratory tests) may
be used, however careful consideration should be given to welding procedures. Consideration shall also be given
to the possibility of sulfide stress-cracking and chloride stress-corrosion cracking (see 4.4.3 and 4.4.4). Adequate
provisions should be made for corrosion monitoring (coupons, probes, spools, etc.) and chemical treating.
Because welding can significantly alter the corrosion-resistance of otherwise resistant materials, careful
consideration shall be given to the development of welding procedures.
5.1.3 Sulfide stress-cracking service
The following guidelines should be used when selecting pipe if sulfide stress-cracking is anticipated.
a) Only seamless pipe should be used unless specifications and quality control applicable to this service have
been exercised in manufacturing ERW or SAW pipe.
b) Carbon and alloy steels and other materials that meet the property, hardness, heat treatment and other
requirements of NACE MR0175 may be used in sulfide stress-cracking service.
The most commonly-used pipe grades that meet the above guidelines are ASTM A 106 grade B; ASTM A 333 [9]
grade 6 and API 5L grade B seamless. API 5LX grades may also be used but their welding presents special
problems.
5.1.4 Resistance to brittle fracture
To ensure adequate resistance to brittle fracture, the selected pipe material grade shall have adequate notch
toughness at its design thickness and design temperature combination.
Non-impact-tested carbon steel pipe (materials) should at least be supplied normalized for services below 0 °C;
and welded components may require PWHT depending on minimum (design) service temperature and thickness of
weldment.
CAUTION — PWHT may reduce mechanical properties of API 5L X pipe material grades.
ASTM A 333 grade 6 is an impact-tested carbon steel suitable for cold service and should have adequate notch
toughness down to – 46 °C. PWHT may be required for certain minimum design temperature and weldment
thickness combinations.
5.1.5 Utilities services
Materials other than carbon steel are commonly u
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