Petrobras N-2409-A2

N-2409 REV. A ENGLISH OCT / 2003

PROPERTY OF PETROBRAS 7 pages

FLEXIBLE PIPE CONTEC - SC-05Maritime Installations and Operations

2nd Amendment

This is the 2nd Amendment to Standard PETROBRAS N-2409 REV. A, and it must be securely attached to the front page of the Standard. It is used to alter the text of the Standard in the parts indicated. Items are void and will be revised later: 3.1.11 Carcass Interlocked metallic construction that is used as the innermost layer to prevent total or partial collapse of the internal pressure sheath or pipe due to pipe decompression, external pressure, tensile armour pressure and mechanical crushing loads. Note: When used to protect the external surface of the pipe, it is called anti-abrasive

protection. 3.1.77 Product Generic term, used to designate any element of the flexible pipe system (for example: pipe, ancillary component, or accessory, whichever is applicable).


2nd Amendment

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TABLE 6 - FLEXIBLE PIPE LAYER DESIGN CRITERIA

Design Load Cases and Combinations

Service Conditions Installation

Normal Operation

Recurrent Operation

Extreme Operation

Abnormal Operation

FAT

Flexible Pipe Layer Design Criteria

Functional and environmental

Functional, environmental and accidental




Creep The maximum allowable reduction in wall thickness below the minimum design value, due to creep into gaps in the supporting structural layer, shall be 30 % under all load combinations. Internal

Pressure Sheath Strain

The maximum allowable strain shall be 7.7 % for PE and PA, 7.0 % for PVDF in static applications, and 3.5 % for PVDF in dynamic applications. For other polymer materials the allowable strain shall be as specified by the manufacturer, who shall document that the material meets the design requirements at that strain.

Stresse 0.80

Internal Carcassa

Buckling Loadb,c

0.67 for Dmax 300 m {[(Dmax 300)/600] x 0.18 + 0.67} for 300 m < Dmax < 900 m

0.85 for Dmax 900 m

Stress 0.67 0.85 0.85 0.80 0.85 0.91

Tensiled Armours

Buckling Load 0.67

Stressd,e 0.55 0.85 0.85 0.80 0.85 0.91

Pressure Armours Buckling

Loadb,c for Smooth Bore Pipe

0.67 for Dmax 300 m {[(Dmax 300)/600] x 0.18 + 0.67} for 300 m < Dmax < 900 m

0.85 for Dmax 900 m

Holding Bandage Stress

f 0.55

a) The mechanical loads to which the internal carcass may be subjected shall be as specified for the tensile and pressure armours;

b) Dmax is the maximum specified water depth including tidal and wave effects. c) Utilizations greater than 0.67 are only allowed for pipes designed under Revision A of this Standard and if design

methodology against hydrostatic collapse has been validated and reviewed by IVA for the specified pipe; d) The design criterion for the pressure and tensile armours is permissible utilization as defined in item 5.3.1.4; for

compressive stresses in the tensile armour that can cause armour buckling, see item 5.3.2.6; e) For installation loading, the stress can achieve the material yield strength in one of the following layers: either the

carcass or the pressure armour provided that in the other one the utilization be respected; f) Utilization = stress/structural capacity, where the structural capacity is equal to 0.9 times the tensile strength of the

bandage; g) Utilizations indicated in the TABLE 6 are applicable to those stresses, strain, loading and failure modes mentioned

in this Standard; manufacturer shall submit to the purchaser the intended utilization necessary in order to avoid other failure modes not foreseen herein.


2nd Amendment

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5.2.3 The design methodology shall account for the effects of wear, corrosion, manufacturing processes, dimensional changes, creep and ageing (due to mechanical, chemical and thermal degradation) in all layers, unless the pipe design is documented to not suffer from such effects. In order to predict the pipe hydrostatic collapse resistance, such prediction shall be based on the minimum value obtained from the design methodology, by taken into account, through a statistical approach, the possible reductions in the pipe resistance coming from, for instance, (i) the variations of the manufacturing processes and (ii) the spreading of the qualification test results. If the manufacturer design methodology is not validated, the normal distribution and three standard deviations (at the safety side), shall be adopted, from test results, to estimate, the pipe hydrostatic collapse resistance to external pressure. 8.1.2 Unless otherwise mutually agreed, manufacturer shall submit the purchaser (and also IVA, in case of prototypes), at the specified times, the following documents:

a) to e) remain unchanged; f) as-built documentation: before the delivery of the pipe and any time on request,

for a period equivalent to the specified service life; g) operating manual: remains unchanged; h) qualification test procedures, if production tests are required: prior to test run; i) qualification test reports, if production tests are required: prior to

commencement of manufacture or before the delivery of the pipe, as per contractual arrangement;

j) if the supply of prototype is allowed by the contractual arrangements, additional documentation, required by item 5.2.6: as per schedule of the prototype developing and qualification program mutually agreed at the commencement of contract.

ANNEX C C-1.1.2 This ANNEX C defines some standardized basic qualification test procedures applicable to conventional flexible pipes (Pipes which concept follows the configuration of layers and end fitting showed, respectively, in Figures 6 and 8 of API RP 17B). Also, these procedures are only valid for product concepts which have been already considered field proven by the purchaser. C-1.2.2 Identification and expression of the variables to be used for data gathering, reports or any test document shall use the following terms (for a given pipe cross section, horizontal and vertical diameters, mean diameters measured at 2 different positions, 90 apart one from the other):

a) LI - initial length; b) LL, LR - loaded and residual lengths, respectively; c) DVI, DHI - initial vertical and horizontal diameters, respectively; d) DVL, DHL - loaded vertical and horizontal diameters, respectively; e) DVR, DHR - Residual vertical and horizontal diameters, respectively; f) DMI, L, R - mean diameter, initial (I), loaded (L) or residual (R) values:

2DHDV

DM R,L,IR,L,IR,L,I+=


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g) OVI,L,R - sample ovalization (see definition, item 3.1.75), initial (I), loaded (L) or

residual (R) values:

RL,I,RL,I,

RL,I,RL,I,RL,I, DHDV

DHDVOV +

=

h) percent length deformation for loaded sample and residual, respectively:

100L

LLLI

ILL

= and 100

LLLL

I

IRR

=

i) percent diameter deformation for loaded sample:

100DV

DVDVDVI

ILL

= and 100

DHDHDHDHI

ILL

=

j) percent residual diameter deformation:

I

IRR DV

DVDVDV = and I

IRR DH

DHDHDH = C-2.2.1.1 The purpose of this test is to verify the pipe elongation, diametric deformation, and twist against the design predictions and pipe tensile capacity. This test shall check the consequences on pipe performance characteristics such as reduction of structural capacity to buckling and pull out or rupture of tensile armours from the end fittings. Also, this test shall check the axial stiffness informed by the manufacturer. If required, this test may also check the structural damping of the pipe, with the same purpose. Manufacturer shall previously inform the pipe maximum tensile capacity and the theoretical curve Tension x Axial Deformation for the test temperature. Test results shall be in accordance with these predictions. A second stage of this test shall be performed up to sample rupture. Failure mechanism and location shall be recorded. When internal diameter pig measuring is required, manufacturer shall previously inform the maximum allowed deformation for which the pipe hydrostatic collapse resistance criteria are not affected, for the specified maximum water depth. C-2.3.2.3 At the second stage, the external pressure is increased at a maximum rate of 10 MPa/min. Before the predicted collapse is reached, the pressure shall be stabilized during at least 15 minutes in 2 intermediate pressure steps (equally estimate in relation to the predicted collapse pressure). Sample is than led to the collapse. C-2.3.3.2 For the second stage, the measured collapse pressure shall be equal (see Note 1) or greater than the predicted pipe hydrostatic collapse resistance (see Note 2), estimated by the manufacturer, which shall comply with the requirements of clauses 5.2.3 and 5.3.1.1 of this Standard.


2nd Amendment

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Notes: 1) For the purpose of this test criterion, the following applies: a) if the manufacturers design methodology is validated (reference item 5.2.2.2 of

this Standard) and if a conservative design approach is adopted (reference item 5.2.3), it is improbable that the measured collapse test is equal or close to the predicted pipe hydrostatic collapse resistance; in case this coincidence occurs, the purchaser may require further collapse tests, in order to confirm if the predicted pipe hydrostatic collapse resistance is at the safety side; the need of new tests would be defined by also taking into account how close are the following values: - the predicted pipe hydrostatic collapse resistance; - the ratio between the design external pressure and the specified utilization;

b) if the design methodology is not validated, manufacturer shall demonstrate the predicted pipe hydrostatic collapse resistance, by means of a statistic approach (reference item 5.2.3 of this Standard), based on additional test results carried out in the same pipe structure.

2) As per TABLE 6 of this Standard, the predicted pipe hydrostatic collapse

resistance shall be equal or greater than the ratio between the design external pressure and the specified utilization.

C-2.4.3.2 In addition, the same sample shall be subjected to the hydrostatic collapse test. For criteria for collapse test, see item C-2.3.3.2 of this ANNEX. If the pipe is insulated, the sample shall be dissected up to the insulation layer in order to verify the integrity of this material, prior to the carrying out of the collapse test. The manufacturer shall previously inform in the test procedure the criteria for integrity of the insulation material. C-2.5.3 Acceptance Criteria The acceptance criteria for the external diameter deformation, sample ovalization, and longitudinal elongation, for loaded and unloaded conditions, are given in TABLE C-3. TABLE C-3 - ACCEPTANCE CRITERIA FOR THE DIAMETRIC

DEFORMATION / OVALIZATION

Parameter Loaded Unloaded (residual) External Diameter Deformation

-3.0 % DVL +3.0 % -3.0 % DHL +3.0 %

-1.0 % DV R +1.0 % -1.0 % DH R +1.0 %

Ovalization -1.5 % OVL +1.5 % -0.5 % OV R +0.5 % Longitudinal Elongation -1.5 % LL +1.5 % -0.5 % L R +0.5 %

In addition to the criteria in the TABLE C-3 above, the following applies:

a) for longitudinal elongation, axial stiffness of the pipe obtained from the test shall be in accordance with manufacturer predictions;

b) for unloaded condition, criteria for pipe internal diameter deformations shall comply with the manufacturer carcass design tolerance;

c) no structural damage of the end fitting itself (e.g. cracking or rupture of its structure) or of pipe layers (e.g. wire rupture) shall be observed;


2nd Amendment

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d) the result of the hydrostatic collapse of the sample segment subjected to this test shall comply with criteria found in item C-2.3.3.2 of this ANNEX.

C-2.7.1.5 If specified, pipe annulus region may be filled with corrosive fluids, in order to simulate sour service conditions. The recommendations and requirements found in items 9.6.4.1.9 of API RP 17B shall be adopted. C-3.2.5.3 Samples shall be kept in the bath for a period of 1 month with a daily cycle of valve opening and close. Crack and reseat pressures, as per item C-3.2.6 are measured. Afterwards, valves are inspected against internal and external corrosion and internal abrasion. C-4.4.1 General Criteria for All Tests and Pipe Handling Test During Field Test, the following criteria shall be verified:

a) tensile armours of the sample shall not present buckling in any direction; b) sample shall not present kink or corkscrew (corkscrew is defined as an increase

of the pipe diameter due to the change of the lay angle of some few tensile armour wires);

c) sample shall not have any damage in its outer sheath that allows the water ingress into the annulus space, nor any slippage of the outer sheath from the end fitting;

d) sample shall not present visual localized twist; e) sample shall not present any visually identifiable structural or functional

damage; f) caliper collars shall run throughout the sample from the top to the bottom. If not,

further dissection results shall not indicate buckling evidences;

After retrieval and during sample dissection, the following criteria shall be verified:

g) tensile armours of the sample shall not present buckling in any direction; h) deviation of the nominal tensile armour lay angle shall be less than 5 deg or

the corresponding pitch values; i) maximum allowable gap between 2 adjacent wires shall not be greater than

3 times the width of the tensile armour wires, at the same pitch region of these wires and in the interest region under analysis;

j) tensile armour wires shall not be found excessively loose in such a way that they can be easily moved, e.g. by hand without effort;

k) sample shall not have residual deformation greater than 1 % in any measurement of external diameter, at a certain pipe section (DH or DV);

l) for verification of residual twist, sample successive axial marks shall be within 0,2 degree/meter along its lengthwise.

Notes: 1) In case criteria of topics i) to l) are not achieved, manufacturer shall perform

further investigations in order to demonstrate that pipe is keeping its resistance after field test.

2) Purchaser could consider optimization of test samples (e.g. one single sample for more than one test) if: (a) NDE, made available by manufacturer, is able to confirm the criteria listed hereafter, in such a way that dissection, at the end of all tests, is unnecessary (b) planned simulation covers all in service conditions.


2nd Amendment

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ANNEX D

(see page 80) (CONCLUSION)

TABLE D-1 - CONTENTS

N-2409 Chapter or

Items Number N-2409 Chapter or

Items Title N-2409 Page

Number

Description of the Changes in Relation to the Same Standard ISO 13628-2 Numbering of Chapter and

items, If Any, and Record ISO Unchanged Sections And Subsections

C-3 Qualification tests of vent valves 63

C-3.1 General 63 C-3.2 Scope 63

C-3.2.1 Immersion test at high temperature 63 C-3.2.2 Cyclic test 64

C-3.2.3 Seawater long term immersion test 64

C-3.2.4 Test of simulated immersion in sea

bottom 64

C-3.2.5 External sealing pressure test 65

C-3.2.6 Test of reproducibility of crack and reseat

pressures 65

C-3.2.7 Flow test 66

C-4 Basic procedure for field test of a flexible

pipe 66

C-4.1 Objectives 66 C-4.2 Introduction 66 C-4.3 Test description 67

C-4.3.1 First end subsea connection test 67

C-4.3.2 Second end subsea connection test 68

C-4.3.3 Dip Test 69 C-4.4 Acceptance criteria 70

C-4.4.1 General criteria for all

tests and pipe handling test

70

C-4.4.2 Additional criteria for the first and second

connection tests 70

_____________

N-2409 REV. A ENGLISH MAY / 2003

PROPERTY OF PETROBRAS 80 pages and Index of Revisions

FLEXIBLE PIPE

Specification

This Standard replaces and cancels the previous revision.

The Responsible CONTEC Subcommittee provides guidance on theinterpretation of this Standard when questions arise regarding its contents. The Department of PETROBRAS that uses this Standard is fully responsible foradopting and applying the clauses thereof. CONTEC

Comisso de Normas Tcnicas

Technical Requirement: a provision established as being the most adequate and which shall be used strictly in accordance with this Standard. If a decision is taken not to follow the requirement (nonconformity to this Standard) it shall bebased on well-founded economic and management reasons, and be approvedand registered by the Department of PETROBRAS that uses this Standard. It is characterized by the verb forms shall, it is necessary..., is required to..., it isrequired that..., is to..., has to..., only ... is permitted, and other equivalent expressions having an imperative nature.

Recommended Practice: a provision that may be adopted under the conditions of this Standard, but which admits (and draws attention to) the possibility of therebeing a more adequate alternative (not written in this Standard) to the particular application. The alternative adopted shall be approved and registered by theDepartment of PETROBRAS that uses this Standard. It is characterized by theverbal form should and equivalent expressions such as it is recommendedthat... and ought to... (verbs of a nonmandatory nature). It is indicated by theexpression: [Recommended Practice].

Copies of the registered nonconformities to this Standard that may contribute tothe improvement thereof shall be submitted to the Responsible CONTECSubcommittee.

Proposed revisions to this Standard shall be submitted to the ResponsibleCONTEC Subcommittee, indicating the alphanumeric identification and revisionof the Standard, the clause(s) to be revised the proposed text, andtechnical/economic justification for revision. The proposals are evaluated during the work for alteration of this Standard.

SC - 05

Maritime Installations and Operations

The present Standard is the exclusive property of PETRLEO BRASILEIRO S.A. - PETROBRAS, for internal use in the company, and any reproduction for external use or disclosure, without previous express authorization, shall imply an unlawful act pursuant to the relevant legislation through which the applicable responsibilities shall be imputed. External circulation shall be regulated by a specific clause of Secrecy and Confidentiality pursuant to the terms of intellectual and industrial property law.

Foreword

PETROBRAS Technical Standards are prepared by Working Groups - GTs (consisting of PETROBRAS specialists and specialists from PETROBRAS Subsidiaries), are commented by PETROBRAS Units and PETROBRAS Subsidiaries, are approved by the Responsible Subcommittees - SCs (consisting of specialists belonging to the same specialty, representing the various PETROBRAS Units and PETROBRAS Subsidiaries), and ratified by the CONTEC Plenary Assembly (consisting of representatives of the PETROBRAS Units and PETROBRAS Subsidiaries). A PETROBRAS Technical Standard may be submitted to revision at any time by the responsible Subcommittee and shall be reviewed every 5 years to be revalidated, revised or cancelled. PETROBRAS Technical Standards are prepared in accordance with PETROBRAS Technical Standard N - 1. For complete information about PETROBRAS Technical Standards see PETROBRAS Technical Standards Catalog.


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1 SCOPE 1.1 This Standard is based on standard ISO 13628-2 and establishes additional requirements, exceptions and other modifications for supplying submarine high pressure unbonded flexible pipes. 1.2 This Standard should also be used by manufacturers when developing prototypes and when evaluating flexible pipes, for installation and operation phases, including damaged and repaired pipes. Note: Alternative design methods and criteria may be used for new developments, if

previously agreed upon by the parties. Despite of section Introduction of standard ISO 13628-2, it is mandatory for the manufacturer to identify any variations from this Standard and provide details to purchaser.

1.3 This Standard does not provide specific design requirements for flexible pipe ancillary components and accessories, but contains some requirements regarding the following:

a) the scope of validation and verification of their design methodologies by the Independent Verification Agent;

b) coating protection. 1.4 Unless otherwise specified above, Section 1 - Scope of standard ISO 13628-2 applies to this Standard. 1.5 The current revision of this Standard shall be applied for supplies beginning from its issue date. 1.6 This Standard contains Technical Requirements and those regarding documentation to be submitted. 1.7 Sections and subsections of standard ISO 13628-2 which are not found herein are in force while new sections or subsections (i.e. which are not found in the ISO Standard) have been included hereafter. The numbering of ISO sections or subsections is unchanged while new sections or subsections are numbered in the sequence. See Contents, which indicates the changes, the inclusions, and the unchanged sections or subsections of standard ISO. 2 SUPPLEMENTARY DOCUMENTS The documents listed in items 2.1 and 2.2 are mentioned in the text and contain valid requirements for the present Standard.


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2.1 Base Standard

ISO 13628-2:2000 - Petroleum and Natural Gas Industries - Design and Operation of Subsea Production Systems - Part 2: Flexible Pipe Systems for Subsea and Marine Applications.

2.2 Normative Reference

API RP 17B - Recommended Practice for Flexible Pipe; API Std 1104 - Welding of Pipelines and Related Facilities; ASME Section IX - Welding and Brazing Qualifications Non-Interfiled

(Boiler and Pressure Vessel Codes); ASTM B733 - Standard Specification for Autocatalytic (Electroless)

Nickel-Phosphorus Coatings on Metal; ASTM B571 - Standard Practice for Qualitative Adhesion Testing of

Metallic Coatings; BS EN 288-8 - Specification and Approval of Welding Procedures for

Metallic Materials Part 8: Approval by a Pre-Production Welding Test.

Note: For the purpose of this Standard, only the following editions are valid:

a) ISO 13628-2 - First Edition - 2000; b) API RP 17B - Second Edition - 1998.

3 DEFINITIONS, SYMBOLS AND ABBREVIATIONS 3.1 For the purpose of this Standard, the definitions of the section 3 of standard ISO 13628-2 are applied, unless otherwise defined below. Additional items to standard ISO 13628-2 are also found hereafter (i.e. item 3.1.46 and others in the sequence). 3.1.11 Carcass Interlocked metallic construction that is used as the innermost layer to prevent total or partial collapse of the internal pressure sheath or pipe due to pipe decompression, external pressure, tensile armour pressure and mechanical crushing loads. Note: When used to protect the external surface of the pipe, it is called outerwrap. 3.1.19 Fishscaling Angle

a) for a tensile armor wire, on a pipe cross section, the angle between the tangent of the pipe section and the orientation of the width, at the centroid of the wire section [see FIGURE 1 (a)];

b) for a pressure armor profile, on a longitudinal pipe section, the angle between the profile, in its width direction, and the pipe cylindrical generatrix, at the centroid of the profile section [see FIGURE 1(b)].


4

(a)

(b)

FIGURE 1 - FISHSCALING 3.1.20 Independent Verification Agent Independent party or group, selected by the manufacturer and accepted by the purchaser, that is responsible for the verification and review of (1) design methodologies and criteria, (2) manufacturing processes and tolerances, and (3) product, flexible pipe system and prototype performances in the light of the technical literature, analyses, test results, and other information provided by the manufacturer. 3.1.24 Jumper Short flexible pipe used in subsea and topside, for static or dynamic applications. Note: Unless otherwise specified by the purchaser, jumper shall have an interlocked

pressure armour overlying the internal pressure sheath. 3.1.29 Quality Conformance to specified requirements, which shall include servicing and traceability of materials and products. 3.1.34 Smooth Bore Flexible pipe with an internal pressure sheath, as the inner most layer and with a leak proof intermediate sheath, applied outside the pressure armour, and sealed in the end fitting.


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3.1.40 Third Party An independent party, accepted by the purchaser and qualified to witness, confirm or approve the referenced data, result, procedure, test or qualification regarding a product (i.e. flexible pipe, ancillary component, or accessory). Notes: 1) Whenever the product is a prototype, the third party is the independent

verification agent. It also applies if purchaser requires confirmation or approval of a specific product performance, characteristic or test procedures and results.

2) In case that a product has already been qualified by the purchaser, for a specified application, third party is defined as per standard ISO 13628-2, provided that it is previously accepted by the purchaser.

3.1.46 Abnormal Operation Condition Operation condition for which Pc (yearly combined probability of occurrence), for the functional, environmental, and accidental loads, is equal to 10-4. 3.1.47 Accessory Generic term used to designate every item that is not a constitutive part of the pipe (including end fittings) and of its ancillary components. Note: Examples of pipe accessory are bolts and nuts, sealing rings, bend stiffener

stopper, and bend stiffener adapter for I-tube. 3.1.48 Anti-Abrasive Protection Accessory used to protect dynamic risers against abrasion in the TDP region. 3.1.49 Buckling of Tensile Armors Buckling of the tensile armors in the radial or any other direction caused by axial compression (true wall compression), associated or not with pipe bending, twist or torsion. Note: Birdcaging is a radial buckling of the tensile armors. 3.1.50 Buoyancy Module Ancillary component used to provide distributed flotation over discrete points of a section of the flexible pipe in order to make feasible the achievement of a particular pipe configuration. 3.1.51 Buoyancy Tank Ancillary component used to provide concentrated flotation of segments of a flexible pipe in order to make feasible the achievement of a particular pipe configuration.


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3.1.52 Carcass Design Tolerance Carcass deviation of its ID roundness that the manufacturer must take into account when conservatively establishing the collapse and crushing capacities of the pipe, considering the effects from the manufacturing process, specified installation methods, equipment, and conditions. 3.1.53 Certifying Authority Third party chosen by the government authority or by the purchaser for certifying that the product is designed, manufactured, tested or installed in compliance with the specified documentation and laws and regulations issued by the country institutions where the above equipment will be installed. 3.1.54 Configuration of Flexible Pipe Geometrical shape of the pipe, during installation or operation, that varies according to the distribution of weight and buoyancy along the pipe, for instance. Common riser configurations are: Free-hanging, Lazy-S, Steep-S, Lazy-Wave, and Steep-Wave. 3.1.55 Crushing Loads Temporary compressive guidance-induced loads or localized radial loads imposed to the pipe, during its installation (laying or retrieval operations) by typical laying equipment such as tensioners, wheel, sheave, chute, gutter, and handling collars. Crushing loads are classified as the following (see FIGURE 2).

TIME

DOUBLE AMPLITUDE OF VARIATION FROM THE LAYING VESSEL

DESIGN CRUSHING LOAD (UTILIZATION AS PER TABLE 6) PIPE

MAXIMUM CRUSHING LOAD

CRUSHING VARIATION CURVE

REQUIRED CRUSHING LOAD

MINIMUM CRUSHING LOAD (HOLDING THE PIPE)

LAYING EQUIPMENT

CRUSHING LOAD

FIGURE 2 - CRUSHING LOADS 3.1.55.1 Design Crushing Load For a particular pipe application, it is the maximum crushing load that the pipe withstands considering an extra margin that corresponds to the utilization indicated by 5.1.3.3. This load includes the squeeze effect that is induced by the tensile armours.


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3.1.55.2 Loads Induced by the Laying Equipment:

a) minimum crushing load:

- for a particular laying condition and application, it is the load, induced by the laying equipment, which is necessary for holding all the suspended line of connected pipes during their installation;

b) required crushing load: - load that refers to the minimum crushing load, increased by the amplitude of

the variation of this load coming from the laying equipment; Note: Amplitude of the variation means that one caused by the control devices of the

laying equipment resulting, e.g., from the characteristics of these devices and, also, the variations coming from the pipe external diameter.

c) maximum crushing load: - load that refers to the minimum crushing load, increased by two times the

amplitude of the variation of this load coming from the laying equipment; it corresponds to the maximum expected value to be applied to the pipe (by the laying equipment) during its installation.

3.1.56 Design External Pressure Maximum hydrostatic external pressure to which the pipe shall be subjected during its life, which varies according to the maximum water depth specified by the purchaser, including tidal and wave effects. 3.1.57 Design Tension Maximum tensile load to which the pipe shall be subjected during its life. Note: For flowlines, the design tension occurs during its installation. For risers, the

design tension is obtained from the most critical between the operating or installation loadings.

3.1.58 Extreme Operation Condition Normal operation condition for which the yearly combined probability of occurrence - Pc - of the functional, environmental, and accidental loads is equal to 10-2. 3.1.59 Far Position Static position of the riser top connection, when the floating unit is displaced in the riser plane, in an orientation, which causes the maximum stretch of the riser for the specified offset. In such situation, the riser top region is far from riser bottom one (see FIGURE 3).


8

SEAFLOOR

OFFSET

1

OFFSET

32

2 - NEUTRAL POSITION

SEA LEVEL

3 - NEAR POSITION

1 - FAR POSITIONWHERE:

FIGURE 3 - POSITIONS OF THE RISER 3.1.60 Flexible Pipe System A fluid conveyance system, connected to field equipment in both extremities, in operation or ready to operate, for which the flexible pipe(s) is the primary component and includes ancillary components and accessories attached directly or indirectly to the pipe(s). 3.1.61 Flowline Flexible pipe, for static application, laid on the seafloor, buried or not, used to link 2 subsea equipment such as, rigid or flexible pipes, manifolds, X-tree or any combination of them. 3.1.62 Free-Hanging Catenary Riser configuration as per standard API RP 17B, item 7.4.1 and FIGURE 4. 3.1.63 Holding Bandage Bandage made of polymeric, fabric or fiber reinforced tape wound around the tensile armours, attaching and compressing their wires/strips against the pipe body to avoid buckling of these wires/strips. 3.1.64 In Service Inspection In-service periodic measuring or verification of the product characteristics (or other features of the system/surroundings and that can cause impact in the product integrity) in order to detect and prevent against defects or non-conformities in it and to determine if the product can safely comply with the intended performance, as specified (or with revised performance limits if they are properly established after documented downgrade analysis).


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Note: In service means installation or operation phases, whichever is applicable. 3.1.65 In service monitoring In-service continuous or periodic measuring or verification of variables related to integrity with the followings purposes:

a) to assess the product degradation or to predict its remaining service life; b) to detect, in service, abnormal behavior of the product/flexible pipe system or to

give sufficient warning of imminent failures preventing accidents; c) to detect defects through continuous checking when periodic inspection cannot

detect non-conformities that occur randomly, accidentally or due to operational error (e.g. outer sheath damage during installation, in locations of difficult access);

d) to check the design premises and methodology predictions in order to verify uncertainties from the used models (i) to calculate loads, fatigue accumulated damage and wear, (ii) to predict responses of the product to the imposed loadings (e.g. displacements, strains, configuration lengthwise, and motions), and (iii) to check product capacity and utilization factors; it includes monitoring of external and internal environments, floating unit responses and operational practices (e.g. load-out and draft of a FPSO);

e) to check behavior of prototype, specially its characteristics/capacity linked to unprecedented use of materials, design methodologies, product concepts or applications (loadings and exposure).

Note: In service means installation or operation phases, whichever is applicable. 3.1.66 Laying Tension Maximum tensile load to which the pipe shall be subjected during installation (laying or retrieval operations). 3.1.67 Lazy-S Riser configuration as per standard API RP 17B, item 7.4.1 and FIGURE 4. 3.1.68 Lazy-Wave Riser configuration as per standard API RP 17B, item 7.4.1 and FIGURE 4. 3.1.69 Maintenance All activities related to the action of correction and preservation intended to avoid any kind of problem or non-conformity related to the flexible pipe system are defined as maintenance.


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3.1.70 Maximum Pressure Differential Maximum difference for a given pipe cross section, between the design external pressure and the minimum internal one experienced during its life (installation and operation conditions). 3.1.71 Minimum Internal Pressure Minimum internal specified pressure experienced by the pipe during its life (installation and operation conditions). 3.1.72 Near Position Static position of the riser top connection, when the floating unit is displaced in the riser plane, in an orientation which causes the minimum stretch of the riser for the specified offset. In such situation, the riser top region is near from riser bottom one (see FIGURE 2). 3.1.73 Neutral Position Static position of the riser top connection corresponding to the position of the floating units without the influence of winds, currents or waves (see FIGURE 2). 3.1.74 Offset For a given direction, it is the maximum vessel displacement due to environmental loading. Static offset (also called mean offset) is the vessel displacement due to combination of current, wave, drift and wind. Dynamic offset (also called extreme offset) is the static offset combined with wave frequency and low frequency motions. 3.1.75 Ovalization As per standard API RP 17B, item 3.1.17, but applied to pipe or pipe layer as referred in the specific clause (e.g. carcass ovalization). 3.1.76 Pliant-WaveTM Riser configuration based on the Lazy wave one, but in which the displacements of the TDP region of the riser are restricted by a dead weight attached to the pipe, at this region (see FIGURE 4).


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SEAFLOOR

SEA LEVEL

DEAD

CLAMPS

CABLES

BUOYANCY MODULES

FIGURE 4 - PLIANT WAVETM

3.1.77 Product Generic term, used to designate any element of the flexible pipe system (i.e. ancillary component, or accessory, whichever is applicable). 3.1.78 Production Tests Tests which purpose is to confirm the product performance and, indirectly, check the control of the manufacturing process. The purchaser can require them, even if a product design is considered already qualified (i.e. product is not a prototype). Procedures for carrying out production tests are generally those basic ones required for prototype qualification tests. 3.1.79 Prototype Product which concept, constituting materials, design methodologies, manufacturing processes, and prototype testing results have not been reviewed and accepted by an Independent Verification Agent and which performance (for a specific application) has not been approved by the purchaser through results, submitted by the manufacturer, of theoretical complementary analyses and of prototype qualification tests. 3.1.80 Prototype Tests Tests that are performed to verify the performance of prototypes. They may be full-scaled tests or may be carried out on samples (at benches or at the field). Prototype tests may be special ones not previously standardized, as they depend on the grade of innovation of the product concept, for example.


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3.1.81 Prototype Development Tests Those tests which objective is to verify if the design concept and if the manufacturing processes result in products that achieve the specified performance. They are tests planned, designed and carried out in the design growing phase in order to confirm the performance of the prototype and of its materials, for the intended application, and to confirm that the identifiable failure modes will not occur during the proposed product service life; their objectives are also to characterize materials (mainly alternative ones) and to optimize product design and manufacturing processes. 3.1.82 Prototype Qualification Tests Those tests which objective is to confirm that a representative product sample from the manufacturing process (see note), originated from an optimized design, complies with the specified performance, taking into account predicted failure modes, loading, and exposure and safety margins. They are carried out provided that the independent verification agent has approved the prototype development tests, if any. For industrial application in prototype construction (supply of extensive batches, lots), material characterization shall be included in this classification, if the development tests have not been performed in representative industrial scale sampling. Note: At this stage (i.e. prototype qualification), manufacturing process is carried out

under controlled conditions for long running production, being the same of that to be used to produce the actual product intended for operation in the field.

3.1.83 Recurrent Operation Condition Normal operation condition which considers all functional loads (but pipe with maximum operating pressure) and 100 year environmental conditions. 3.1.84 Riser Pipe, for both static and dynamic applications, used to convey fluids between any of the following:

a) floating vessels or fixed platforms and subsea equipment (including flowlines); b) an intermediate mid-water equipment (or buoy) to a subsea equipment

(including flowlines); c) floating vessel of fixed platform to an intermediate mid-water equipment (or

buoy); d) any combination of the following units: floating vessels or fixed platforms.

Note: Unless otherwise specified by the purchaser, riser shall have an interlocked

pressure armour overlying the internal pressure sheath. 3.1.85 Riser Hang-Off Structure for supporting riser at the connection to a production unit (jacket, semi-sub, tanker).


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3.1.86 Shutdown Internal Pressure Internal pressure (remaining in the pipe) after the system shutdown of the production unit caused, for example, when the limit environmental condition is exceeded. 3.1.87 Shut-in Pressure Highest value of the internal pressure considering, among others, the pressure necessary to start the plant operation, the breaking pressure of the valves of the gas lift compression system or the overpressure caused by the closing of safety valves. 3.1.88 Steep-S Riser configuration as per standard API RP 17B, item 7.4.1 and FIGURE 4. 3.1.89 Steep-Wave Riser configuration as per standard API RP 17B, item 7.4.1 and FIGURE 4. 3.1.90 Tensioner Mechanical device used to apply tension or support a pipe, during its installation, considering all suspended pipes connected to it. Also called caterpillar. 3.1.91 Thermal Exchange Coefficient - TEC Coefficient which provides the heat loss (expressed in Watts) of 1 m of pipe when subjected to 1 C difference between its internal and external surfaces. Its numerical value depends on the condition of the annulus: e.g. dry or wet. 3.2 Symbols and Abbreviated Terms In addition to those symbols and abbreviated terms found in item 3.2 of standard ISO 13628-2, the following are applicable:

Dfat - Accumulated Fatigue Damage Calculated by the

Palmgreen-Miner Rule; DFF - Design Fatigue Factors; PA-11 - Polyamide 11; Pc - Yearly Probability of Occurrence of Such a Combined

Loading; TDP - Touch Down Point; TEC - Thermal Exchange Coefficient; ISO - International Organization for Standardization; IVA - Independent Verification Agent.


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4 FUNCTIONAL REQUIREMENTS AND RECOMMENDATIONS For the purpose of this Standard, the original section and subsections of standard ISO 13628-2 are applied, unless otherwise modified below. Additional items to standard ISO 13628-2 are also found hereafter. 4.1 General 4.1.2 Functional requirements not specifically required by the purchaser and that may affect the design, materials, manufacturing, testing, performance, in service inspection and monitoring, and maintenance of the pipe (and of the flexible pipe system) shall be proposed by the manufacturer and submitted to the purchaser in the Design Premise. 4.2 Overall Requirements 4.2.1 Flexible Pipe The minimum overall functional requirements of the flexible pipe that shall be demonstrated by the manufacturer are as follows:

a) to e) remain unchanged; f) by adopting the specified basic installation procedure, including the pull-in/ pull-

out methods, the pipe (and its ancillary components and accessories) shall be capable to be installed (lowered and recovered) and connected at both extremities in the field (e.g. at the specified subsea equipment and floating unit) by means of the specified vessel(s) and equipment (it includes, for instance, tensioners, pull-in/ pull-out machines, hydraulic collar, winches, and cables);

g) the pipe and its ancillary components/ accessories shall be capable to be shipped, handled, transferred, stored, loaded to the installation vessel by means of the specified equipment and facilities.

4.6 System Requirements and Recommendations 4.6.1 Minimum System Requirements and Recommendations 4.6.1.2 Application Definition The flexible pipe system shall be specified as composed of either flowline, riser or jumper. The flexible pipe application shall be specified as either static or dynamic. For the dynamic application, manufacturer shall calculate the expected number of load cycles and their magnitudes and periods based on specifications provided by the purchaser such as environmental data and floating unit information (e.g. RAO and geometry). 4.6.1.12 Installation Requirements 4.6.1.12.1 The purchaser should specify performance requirements for the installation services to be provided, considering the following as a minimum:


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a) for installation by the purchaser, the purchaser should specify any load

restrictions, clamping/ tensioner loads, overboarding chute requirements, installation tolerances, and port facilities limitations; based on the product characteristics and limitations, any intended modification or refurbishment of vessel/equipment proposed by the manufacturer shall be approved by the purchaser previous to contractual arrangement between these parties;

b) remain unchanged. 4.6.1.12.2 The purchaser should specify requirements for the recoverability and reusability of the pipe throughout its service life. The pipe shall be designed to withstand, at least, 4 deployments and 4 recoveries similar to the installation conditions as per original specification. 4.6.1.14 Reuse Requirements

a) for the recoverability and reusability of the flexible pipe throughout its service life, the manufacturer, based on information provided by the purchaser and agreed to be considered appropriated, shall assess (whichever applicable) the predicted remaining capacity and service life for the fatigue of metallic layers, aging of polymers, corrosion, wearing and for other kinds of degradations;

b) for this purpose, purchaser shall allow the manufacturer to perform necessary inspections and tests in the entire pipe or in its samples in order to detect non-conformities, defects, and stage of degradation.

5 DESIGN REQUIREMENTS AND RECOMMENDATIONS For the purpose of this Standard, the following sections and subsections of standard ISO 13628-2 have been modified as written hereafter. Additional items to standard ISO 13628-2 are also found hereafter. 5.1 Loads and Load Effects 5.1.2 Load Classes 5.1.2.1 As listed in TABLE 5 and TABLE 5A, loads are classified as functional, environmental (external) or accidental, as follows:

a) functional loads are all loads on the pipe in service or during installation, including all loads which act on the pipe in still water except wind, wave or current loads;

b) and c) remain unchanged. Note: Load classes and subclasses are listed in the left column of TABLE 5 and 5A.


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TABLE 5 - LOAD COMBINATIONS OF LOAD CLASSES, LOAD CONDITIONS

Normal Operation

Load Conditions Recurrent Operation

Extreme Operation

Abnormal Operation

Functional Loads a) loads due to mass and buoyancy of pipe, contents

and attachments, both temporary and permanent; x x x

b) internal pressure as specified in 4.4.2; Max. operating pressure design pressure design pressure

c) pressure and thermal expansion and contraction loads; x x x

d) external pressure; x x x e) external soil or rock reaction forces for trenched,

buried, or rock dumped pipes; x x x

f) static reaction and deformation loads from supports and protection structures; x x x

g) temporary installation or recovery loads, including applied tension and crushing loads, impact loads and guidance induced loads;

x x x

h) residual installation loads, which remain as permanent loads in the pipe structure during service;

x x x

i) loads and displacement due to pressure and tension induced rotation; x x x

j) testing pressures, including installation, commissioning and maintenance pressures; x x x

k) interaction effects of bundled or clamped pipes; x x x l) loads due to rigid or flexible pipe crossings, or

spans; x x x

m) loads due to positioning tolerances during installation; x x x

n) loads from inspection and maintenance tools. x x x Environmental loads

Loads and motions caused directly or indirectly by all environmental parameters as specified in TABLE 2

100 year conditions

(c)

conditions to meet Pc = 10-2

Survival conditions

Accidental loads Loads and motions caused directly or indirectly by accidental occurrences, including the following:

1) dropped objects Not applicable (a) (b) 2) trawl board impact Not applicable (a) (b) 3) internal over-pressure Not applicable (a) (b) 4) compartment damage or unintended flooding Not applicable (a) (e) 5) failure of thrusters Not applicable (a) (e) 6) DP failure Not applicable (a) (e) 7) anchor line failure Not applicable (d) (b) 8) failure of turret drive system Not applicable (a) (e) a) Combinations of the above functional, environmental and accidental loads, as shown in TABLE 6, shall be

analyzed if the yearly combined probability of occurrence Pc is equal to 10-2. b) Combinations, as shown in Table 6 of the above functional, environmental and accidental loads, shall be

analyzed if Pc is equal to 10-4. c) Unless otherwise specified by the purchaser, 100-year conditions mean the combination of the following: (i)

100-year wave, 10-year current and the extreme offset and (ii) 10 year wave, 100 year current and the extreme offset.

d) Combinations of the above functional, environmental and accidental loads, as shown in TABLE 6, shall be analyzed if the yearly combined probability of occurrence Pc is equal to 10-2. Unless otherwise specified by the purchaser, the following combination shall be considered, as loading condition with Pc = 10-2 for extreme normal operation condition: (i) 100 year wave, 10 year current and the offset of one line failed and (ii) 10 year wave, 100-year current and the offset of one line failed.

e) Combinations, as shown in Table 6 of the above functional, environmental and accidental loads, shall be analyzed if Pc is equal to 10-4. Unless otherwise specified by the purchaser, the combination of annual wave and annual current with the accidental load shall be considered for survival conditions.


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TABLE 5A - ANNUAL PROBABILITIES FOR INSTALLATION

Type of Load Installation

Functional Loads Expected, specified, or extreme value.

Probability of exceedance according to season and duration of installation period.

If abandonment is possible, the maximum weather in a period 3 times the expected installation duration may be used.

Environmental Loads

If abandonment is not feasible, a more conservative approach shall be used or the duration of the operation reduced to a period where reliable weather forecast is available (typically hours).

Accidental Loads As appropriate to installation method

5.1.3 Load Combinations and Conditions 5.1.3.2 The design load conditions that shall be analyzed are installation, normal operation (recurrent and extreme), abnormal operation and factory acceptance testing. Load combinations shall be as defined in the notes for TABLE 5, in TABLE 5A, and column headings in TABLE 6. Load combinations with a yearly probability of occurrence less than 10-4 can be ignored. FAT load combinations shall be defined by the manufacturer based on the FAT procedures. 5.1.3.3 Design checks shall be carried out of any temporary conditions specified by the purchaser or the manufacturer. These shall be subjected to the same design criteria as the design load conditions, as specified in TABLE 6 and TABLE 6A.


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TABLE 6 - FLEXIBLE PIPE LAYER DESIGN CRITERIA

Design Load Cases and Combinations

Service Conditions Installation

Normal operation

Recurrent Operation

Extreme Operation

Abnormal Operation

FAT

Flexible Pipe layer Design Criteria






Creep The maximum allowable reduction in wall thickness below the minimum design value, due to creep into gaps in the supporting structural layer, shall be 30 % under all load combinations. Internal

Pressure Sheath Strain

The maximum allowable strain shall be 7.7 % for PE and PA, 7.0 % for PVDF in static applications, and 3.5 % for PVDF in dynamic applications. For other polymer materials the allowable strain shall be as specified by the manufacturer, who shall document that the material meets the design requirements at that strain.

Stresse 0.80

Internal Carcassa

Buckling Loadb,c

0.67 for Dmax 300 m {[(Dmax 300)/600] x 0.18 + 0.67} for 300 < Dmax < 900 m

0.85 for Dmax 900 m

Stress 0.67 0.85 0.85 0.80 0.85 0.91

Tensiled Armours

Buckling Load 0.67

Stressd,e 0.55 0.85 0.85 0.80 0.85 0.91

Pressure Armours Buckling

Loadb,c for Smooth Bore Pipe

0.67 for Dmax 300 m {[(Dmax 300)/600] x 0.18 + 0.67} for 300 < Dmax < 900 m

0.85 for Dmax 900 m

Holding Bandage Stress

f 0.55

a) the mechanical loads to which the internal carcass may be subjected shall be as specified for the tensile and pressure armours;

b) Dmax is the maximum specified water depth including tidal and wave effects. c) Utilizations greater than 0.67 are only allowed for pipes designed under Revision A of this Standard and if design

methodology against hydrostatic collapse has been validated and reviewed by IVA for the specified pipe; d) The design criterion for the pressure and tensile armours is permissible utilization as defined in item 5.3.1.4; for

compressive stresses in the tensile armour that can cause armour buckling, see item 5.3.2.6; e) For installation loading, the stress can achieve the material yield strength in one of the following layers: either the

carcass or the pressure armour provided that in the other one the utilization be respected; f) Utilization = stress/structural capacity, where the structural capacity is equal to 0.9 times the tensile strength of the

bandage; g) Utilizations indicated in the Table above are applicable to those stresses, strain, loading and failure modes

mentioned in this Standard; manufacturer shall submit to the purchaser the intended utilization necessary in order to avoid other failure modes not foreseen herein.


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TABLE 6A - FLEXIBLE PIPE LAYER DESIGN CRITERIA - EXTENSIONS TO ISO

Pipe Layer

Failure Mode Causes/Origins

Consequences to Pipe Structural Capacity

Utilization, maximum elongation, or other design criteria, for the service and installation conditions, as indicated

Loss of interlocking

Bending or Tension with bending

Locally reduced pipe hydrostatic collapse resistance and tension capacity

Design criteria to be demonstrated and submitted in the Design Report for all cases of the service and installation conditions (reference is made to operating MBR item 5.3.1.7)

Carcass

Excessive plastic deformation

Squeeze induced by the tensile armours and crushing loads (e.g. radial compression from the tensioners, launching wheel and hydraulic collars)


No increase of the utilization specified in TABLE 6 is allowed, for the service and installation conditions.

Loss of interlocking

Bending, tension, and crushing loads induced by the installation equipment, or torsion

Locally reduced pipe structural capacity against internal pressure, crushing loads, tension and hydrostatic collapse (possibility of extrusion and leakage of the internal pressure sheath)

Design criteria to be demonstrated and submitted in the Design Report for all cases of in service and installation conditions (reference is made to operating MBR item 5.3.1.7)Pressure Armours

Excessive plastic deformation

Squeeze induced by the tensile armours and crushing loads induced by the installation equipment


No increase of the utilization specified for the carcass in TABLE 6 is allowed.

Tensile armours

Excessive pipe twist

Pipe presents excessive rotation under service and installation conditions (e.g. under maximum design pressure, laying or operating tension or combination of internal pressure and tension) as the tensile armours are not properly designed or manufactured.

Pipe twist, kinking or looping, locally reduced pipe structural capacity against tension and internal pressure, and rupture of tensile armour wires, squeeze of pressure armour or carcass.

Criteria for pipe twist (1): (i) Maximum allowed pipe

rotation is 0.6/m under the laying tension, maximum design pressure, and, in case of riser, under the operating tension, the later associated or not to the maximum design pressure.

(ii) In the unloaded condition (i.e. residual condition, when tension and pressure are relaxed) the maximum allowed pipe rotation is 0.2/m.

Note: Criteria for excessive pipe twist covers only margins against loop and kink.

Therefore, these criteria (allowed pipe twist) shall not be applicable to other failure modes such as pipe crushing (due to the squeeze of the tensile armours) or buckling of the tensile armours, which can be associated (or be anticipated) to the pipe rotation.


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5.1.3.4 The simultaneous occurrence of different load combinations shall be defined in the design premise of the manufacturer which shall comply, with the purchaser specification (load combinations and cases requested by the purchaser), if any. 5.1.3.5 The design load cases to be analyzed shall be derived from the load conditions as specified in item 5.1.2.2, column headings in TABLE 6, including those specified by the purchaser, if any. 5.1.4 Design Load Effects 5.1.4.1 In the pipe design, the manufacturer may allow for the effects of differential pressures provided that it is specified and previously authorized by the purchaser and is clearly indicated in the design premise. Further, the effects of differential pressures shall not be used for the purpose of dimensioning the pipe against hydrostatic collapse, unless otherwise specified by the purchaser. 5.2 Product Design Methodology 5.2.1 Initially and whenever revisions occur, the design methodology and the manufacturing processes of the product and of the flexible pipe system shall be verified by IVA. The documentation submitted for verification of the design methodology and of the manufacturing processes shall include the following, as a minimum:

a) to d), remain unchanged; e) manufacturing and design tolerances, manufacturing induced stresses, welds,

and other effects which influence pipe structural capacity; it includes manufacturing records and analysis through which it can be confirmed that the manufacturing processes are controlled and that the tolerances can be achieved; documentation regarding qualification of special processes and the repair procedures shall be also included due to the possible influence of these processes in the pipe structural capacity;

f) remain unchanged; g) documentation indicating the characterization and the properties of the

materials, as well as their qualification as per Chapter 6. 5.2.1.1 IVA shall have previous complete knowledge of all packages of manufacturers methodologies and criteria. In addition to the above, its review of those packages shall cover, at least, the following items (applicable to any product and flexible pipe system to be delivered):

a) product and flexible pipe system design (including material selection and characterization, global analysis of the flexible pipe system, and product service life analysis and structural dimensioning, for all predicted failure modes);

b) pipe manufacturing and assembling methods (including control of processes and acquisition and treatment of the manufacturing data);

c) prototype development and qualification (including evaluation of experimental data and assurance that samples and test procedures are representative);

d) evidences of the qualification of manufacturers suppliers (i.e. sub-vendors) and qualification of their products.


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5.2.2 IVA shall review and evaluate the design methodology and the manufacturing processes to establish the range of applications for which they are suitable. IVA shall issue a certificate and a design verification report describing the limits and constraints of the design methodology and of the manufacturing processes. The certificate shall be included by the manufacturer in the design report (see item 8.4) and the design methodology verification report shall be available (in Brazil) for review by the purchaser. 5.2.2.1 The certificate and report above mentioned shall cover a validated envelope of product designs and of manufacturing processes (including end fittings, ancillary components and accessories). 5.2.2.2 Design methodologies are considered validated (for a validated envelope of product designs) if IVA has sufficient evidences, provided by the manufacturer, that their predictions are confirmed through a comprehensive set of prototype tests and complementary analysis, taking into account the design methodology uncertainties and the capability and variations of the manufacturing processes, which shall be properly identified by the manufacturer. A statistical approach must be included in the manufacturer documentation to be reviewed in order to confirm that the prototype testing is performed in a representative sampling. 5.2.2.3 IVA may verify (see item 5.2.1) a single product design, but, in this case, the used design methodology would not be considered validated. 5.2.3 The design methodology shall account for the effects of wear, corrosion, manufacturing processes, dimensional changes, creep and ageing (due to mechanical, chemical and thermal degradation) in all layers, unless the pipe design is documented to not suffer from such effects. In order to predict the pipe hydrostatic collapse resistance, the lower bound value, obtained from the design methodology shall take into account, through a statistical approach, (i) the variations of the manufacturing processes and (ii) the spreading of the qualification test results. If the manufacturer design methodology is not validated, a normal distribution and three standard deviations shall be adopted to estimate the pipe hydrostatic collapse resistance to external pressure. 5.2.6 If the product design is outside the validated envelope of product designs (see item 5.2.2) and if its performance, for a specific application1, has not been approved by the purchaser by taking into account the results2 of theoretical complementary analyses and prototype qualification tests, submitted by the manufacturer, then the product is a prototype3 and the manufacturer shall carry out a prototype developing and qualification program to verify the product design, with the following minimum content:

a) detailed description of the pipe concept and of all layers and their functions (see Note 4);

b) detailed description of the concepts of the end fitting, ancillary components and accessories;

c) specification of constituting materials (materials to be used in construction of pipe, end fitting, ancillary components, and accessories) and the their characterization and qualification tests 4 (herein standardized or not, including short and long term testing) (see Note 4);


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d) for dimensioning purposes, description of all possible failure modes of the pipe

(end fitting, ancillary components, and accessories) and of evidences that the corresponding design methodology covers them;

e) detailed description of the manufacturing processes and documentation confirming that they are controlled for producing long pipe sections (> 300 m);

f) carrying out a comprehensive set of development tests based on the identified failure modes;

g) carrying out a comprehensive set of global, service life, and local analysis for the intended service and application range, including conditions for pipe installation, for the available installation equipment;

h) carrying out calculations and dimensioning of ancillary components and accessories;

i) carrying out VIV analysis, when applicable; j) carrying out the fatigue analysis for the intended application range, when

applicable; k) carrying out a comprehensive set of qualification tests [it includes field test, as

per ANNEX C of this Standard (see Note 5)] provided that the previous development tests are successful and the respective product design is optimized;

l) verification by IVA of the design methodologies, the specified criteria, manufacturing processes, and issue of certificate of approval and reports, applicable to the specified product.

Notes: 1) Specific application means functional requirements and recommendations as

described in Chapter 4 of this Standard, including installation and operational information and data.

2) Exception is made to the results of development tests, as per paragraph f) above, which do not need to be approved by the purchaser.

3) Products intended to be manufactured through processes that use (i) machines or controls with any change (in relation to machines and processes of products already qualified) or (ii) that use machines, processes, and workmanship from new plants are also considered prototypes.

4) Utilization for new concept of layers and new materials must be more conservative, i.e. with extra safety margins, than the ones specified in TABLE 6 and TABLE 6A, unless otherwise mutually agreed.

5) Alternatively to the carrying out of field test mentioned in paragraph k) above, if made available by manufacturer, purchaser may accept detailed design and operational information regarding Field-Prototype. Field-Prototype means that the product design is field proven through a performance demonstration of a real complete pipe, of similar structure of the pipe under analysis, under operational conditions equal or more critical than those specified (Reference is made to Chapter 4 of this Standard), designed and manufactured by the same methodology and processes/controls of the pipe under analysis, being all these design and manufacturing packages certified by IVA.

5.2.6.1 The manufacturer shall submit to purchaser a report containing technical information and all the results of the prototype development and qualification program above mentioned, with exception of paragraph f) (development tests). Also, the manufacturer shall submit to purchaser a certificate and a design methodology and manufacturing processes verification report issued by IVA, for the prototype, including the IVA review on the results of all the activities listed in paragraphs a) to k) of item 5.2.6. The prototype qualification tests shall be witnessed by IVA and purchaser, at its discretion, while development test shall be witnessed by IVA.


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5.2.6.2 The prototype qualification tests shall verify fitness-for-purpose for those design parameters, which are outside the previously validated envelope, if any. See standard API RP 17B and ANNEX C for guidelines on test scope and recommendations, which shall be duly complemented in order to incorporate specific investigations on characteristic failure modes and defects of the pipe, not foreseen in the standardized qualification tests. 5.3 Pipe Structure Design 5.3.1 Design Criteria 5.3.1.1 The pipe layers shall be designed according to the criteria specified in TABLE 6 and TABLE 6A, subject to the requirements given in item 5.3.1. Pipe structure shall be designed against all potential failure mechanisms listed in Table 3 of standard API RP 17B and following the recommendations of item 5.4 of standard API RP 17B, unless otherwise herein specified. 5.3.1.3 For stress criterion, the utilization for the internal carcass shall be calculated as specified in item 5.3.1.4. For buckling, utilization is defined as the ratio between the maximum external pressure (the maximum between either the full external pressure due to the maximum water depth or the maximum annulus pressure) and the pipe capacity, taking into account the water depth ranges defined in TABLE 6. Calculated residual deformation due to crushing and squeeze loads shall not cause utilization factor to exceed the criteria found in TABLE 6 and TABLE 6A, for all load combinations. The manufacturer shall evaluate buckling failure modes in the carcass and pressure armours, and shall confirm by analysis that the layers meet the design requirements. Hydrostatic collapse calculations for the carcass may account for the support provided by the pressure armour layer. 5.3.1.8 Fatigue life calculations shall be performed in accordance with item 5.3.4. The predicted fatigue life shall be as per TABLE 6B. Corrosion analysis (in accordance with item 5.3.4) shall show that the material loss from corrosion does not cause utilization factors to exceed the criteria of this sub clause under all load combinations. The fatigue criterion that shall be satisfied is written as Dfat. DFF 1, where Dfat = Accumulated fatigue damage (Palmgreen-Miner rule) and DFF = Design Fatigue Factor.

TABLE 6B - PREDICTED FATIGUE LIFE

Design Fatigue Factors (DFF) Safety class

Low Normal High 3.0 6.0 10.0

5.3.1.8.1 Risers for oil and gas shall have a high safety class while individual water injection risers (i.e. risers for water injection in a single well) shall have a low safety class. For water injection risers in more than one well, normal safety class shall be adopted.


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5.3.1.8.2 The accumulated fatigue damage shall be calculated taking into account the progressive wear of structural layers. If the pipe does not have anti-wear layers, maximum allowable wear of any structural layer shall not exceed 25 % of its thickness. At the end of the specified service life, the utilization factors specified in Table 6 shall be preserved. 5.3.2 Design Requirements and Recommendations for Pipe Layers 5.3.2.1 Internal Pressure Sheath 5.3.2.1.1 As a minimum, the internal pressure sheath shall be analyzed for the following load cases:

a) most critical combination of internal pressure, external pressure (it includes the possibility of outer sheath is damaged and the external pressure is in direct contact with the internal pressure sheath), temperature, operating MBR and polymer condition;

b) as per ISO. 5.3.2.1.5 For dynamic applications, the manufacturer shall have documented test records to verify that crack initiation, due to notch sensitivity and stress raisers (e.g. in case of PVDF is used, protrusion due to the extrusion process over the carcass), does not occur in the material used for the internal pressure sheath. This does not apply to sacrificial layers used in multiple internal pressure sheath constructions. 5.3.2.3 Intermediate Sheath If an intermediate sheath is designed to prevent leakage of annulus fluid outside the layer or to prevent seawater ingress beyond this layer (required for smooth bore pipes), then the design of this sheath shall meet the requirements given in item 5.3.2.1. For dynamic applications, intermediate sheaths shall withstand wear due to relative motion between layers. Wrinkles and cracking due to bending should be avoided. 5.3.2.4 Internal Carcass The design of the internal carcass shall take into account the following:

a) collapse with minimum specified internal pressure, maximum external pressure and carcass design tolerance; the external pressure shall be either the full external pressure acting on the outside of internal pressure sheath or maximum annulus pressure if this exceeds the external pressure;

b) to e), remain unchanged; f) stresses caused by crushing loads, combined or not with tension (when the pipe

is subjected to the squeeze loads from the tension armours), which may cause rupture or excessive permanent (or residual) or temporary deformation of this layer;

g) the existence of a gap between the pressure armour and the internal pressure sheath, if any (in case of the design methodology foresees the back-up support of the carcass when pressure is acting directly in the internal pressure sheath).


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5.3.2.5 Pressure Armours The pressure armours shall be designed to withstand the specified hoop stress; the design shall further ensure that gaps between wires are within the limits necessary to prevent excessive creep extrusion of the internal pressure sheath (reference is made to TABLE 6) and the loss of interlock. Pressure armour design shall take into account the collapse with minimum specified internal pressure, maximum external pressure and maximum layer ovalization. 5.3.2.5.1 Pressure armour shall be designed to withstand the crushing loads combined with tension (when the pipe is subjected to the squeeze loads from the tension armours), induced by the installation methods and equipment. 5.3.2.5.2 For safety reasons, unless otherwise specified, risers shall have an interlocked pressure armour overlying the internal pressure sheath. 5.3.2.5.3 For smooth bore pipes, the external pressure shall be the full external pressure acting on the outside of the leak proof intermediate sheath. Utilization factor against pressure armor buckling is indicated in TABLE 6. 5.3.2.6 Tensile Armours 5.3.2.6.2 The complete pipe structure shall be designed so that the torsional balance and compression strength characteristics of the pipe meet functional requirements. The torsional balance concept shall be in such a way that pipe does not rotate up to the limit of formation of loop, kink, or buckling of the tensile armours. 5.3.2.6.3 TABLE 6A brings a criteria for excessive pipe twist, but it includes only margins against loop and kink. However, the allowable pipe twist shall be reduced if its effects may induce other failure modes, such as the following:

a) pipe crushing (due to the squeeze of the tensile armours); or b) buckling of the tensile armours, when the pipe is subjected to axial (true wall)

compression taking into account the end cap effect, associated or not to bending and torsion loads.

5.3.2.6.4 Tensile armours shall be designed against buckling due to axial (true wall) compression (compression due to hydrostatic external pressure acting on the pipe, added to effective compression, induced by the riser catenary top motions), associated to bending and torsion loads. TABLE 6 defines permissible utilization against buckling which is referred to the limit stress that causes the buckling of the tensile armours, for both conditions of the pipe annulus, dry or flooded. This permissive utilization against buckling is applicable for buckling in any direction (radial and in the cylindrical surface of the layer).


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5.3.2.7 Additional Layers 5.3.2.7.4 Holding bandage shall be designed in order to avoid the tensile armours radial expansion (and, eventually, the radial buckling of armours) caused by axial (true wall) compression, associated or not to bending and torsion loads. Maximum allowable bandage elongation is limited to that one which causes a gap, between the tensile armour wires and the underlying layer, corresponding to 1/2 of the thickness of the armour wire. Utilization factor for stress in the holding bandage is indicated in TABLE 6. It is related to the material tensile strength. This design criterion is applicable for both conditions of the pipe annulus, i.e. dry or flooded of seawater, and for all load conditions (installation and service). 5.3.2.7.5 If a smooth bore pipe is specified for water injection application, a leak proof intermediate sheath, sealed in the end fitting, shall be applied outside the pressure armour in order to prevent the collapse of the internal pressure sheath, even if the annulus is flooded (due to an external sheath damage). 5.3.3 End Fittings 5.3.3.1 The end fittings shall be designed for reliable termination of all pipe layers, so that leakage, structural deformation, or pull-out of wires or extruded layers do not occur throughout the service life of the pipe, taking into account all relevant factors including shrinkage, creep, ageing, and pressure effects. The design methodology for end fittings shall be documented and shall be verified by documented tests and analyses. The methodology shall account for manufacturing tolerances. The design shall allow for support loads from any ancillary components attached to the end fittings, including bend stiffeners and restrictors and accessories used for pipe installation. 5.3.3.2 The design of the end fittings shall ensure sealing of the internal pressure sheath, of the outer sheath, and of the intermediate sheath at the end fittings (when applicable). The latter is required if this sheath is designed to prevent annulus flooding beyond this layer (in case of protecting thermal insulation from seawater contact or in case of smooth bore pipes). The design of the end fittings crimping/sealing mechanism shall ensure that the combined strain induced by the in-service pull-out forces and installation of each end fitting seal ring does not result in failure of the sheath throughout the service life. 5.3.3.3 In the design of the end fittings, axial movements of the carcass relative to the end fittings shall be mechanically restrained. In case of smooth bore pipes, the same is applicable for axial movements of the pressure armours. 5.3.3.5 For dynamic applications, fatigue life calculations shall be performed in accordance with items 5.3.1.8, 5.3.1.8.1 and 5.3.4.


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5.3.4 Service Life Analysis 5.3.4.2 Service Life - Dynamic Applications 5.3.4.2.1 For dynamic applications the service life analysis given in item 5.3.4.1.1 shall first apply. In addition, a fatigue analysis shall be performed for both the pressure and tensile armour layers, which shall take into account all mechanical and dynamic effects that may introduce failure modes into the pipe in the dynamic application. As a minimum, the effects of stress concentration due to bending and strain-hardening (as a result of the end fitting assembly process), wear, fatigue, fretting, material degradation including corrosion, and degradation and draining of lubricant shall be accounted for. 5.3.4.3 Fatigue Analysis For dynamic applications, the analysis of load conditions shall show that the extreme stresses in the pressure and tensile armour layers are below the endurance limit, otherwise fatigue-damage calculations should be performed. Fatigue-damage calculations shall be based on Miners method using design S-N curves, which have been validated for the used wire materials, under the applicable service environmental. Besides, for service life prediction, manufacturer fatigue methodology shall be assessed, by means of tests, in order to quantify the fatigue performance losses of the tensile armour wires inside the end fitting, due to the as built conditions. As built is herein understood when wires are pulled and subjected to local bending moment and shear load introduced by the geometry of the end fitting and by the embedded resin. Also, when wires are strain-hardened during the end fitting assembly process, and subjected to geometric changes. The fatigue life analysis shall also confirm that the internal pressure sheath and outer sheath maintain integrity under the calculated alternating strains. 5.3.4.4 Risers for Reduced Service Life 5.3.4.4.1 If duly designed by the manufacturer, for reduced pipe service life (typically 5 years) and when the purchaser classifications of the flexible pipe system and of the connected equipment are considered to have low risk on safety, environmental damage, and operability of the production system, riser might not have an interlocked pressure armour. In this case, special attention shall be taken regarding the combination of the following:

a) creep extrusion of the pipe internal pressure sheath through the tensile armours gaps at low curvature regions of the riser (e.g. TDP);

b) ageing of the pipe internal pressure sheath due to agents such as time in service, composition and features of the conveyed fluid, including, for instance, chemicals, H2S, CO2, O2, pH, TAN, temperature, and BSW throughout the pipe service life.

5.3.4.4.2 Also, the impact of the reduction of the weight of the riser on its stability during installation and operation, due to the eventual lack of an interlocked pressure armour, shall be taken into consideration by the manufacturer. When preparing the In Service Inspection, Monitoring, and Maintenance/Replacement Programme, manufacturer shall include checking of the riser outer sheath just after the pipe installation (as laid inspection) and during operation in order to minimize risk of failures due to tensile armouring corrosion.


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5.3.5 Global Analysis - Requirements and Recommendations Unless otherwise specified, Global and Local Analyses shall comply with section 8 of standard API RP 17B and with the additional requirements and recommendations presented hereafter. 5.3.5.1 Conventions for referencing meteocean data, vessel position coordinates (riser connection, point for motions) and RAO shall be properly translated to the riser analysis modeling tool in order to generate consistent results. When filling in TABLE A-1 of ANNEX A, purchaser shall inform the conventions of the provided data. 5.3.5.2 The structural damping as cited in standard API RP 17B, item 8.2.3.1.4, shall be assumed as no more than 5 % of critical value corresponding to the wave period. Purchaser may approve the use of higher values if properly justified by the manufacturer by means of analysis and tests results. The above mentioned damping value is associated to Rayleigh damping model used in softwares based on implicit integration scheme. If the manufacturer intends to use a different approach, the values adopted shall be validated against the above mentioned methodology through the comparison of their results. Also, this validation shall be justified and submitted to the purchaser. 5.3.5.3 The global analysis model shall include, for the critical loading cases, the bend stiffener. Results shall demonstrate that the bend stiffener can properly protect the pipe. 5.3.5.4 Motion and Wave Modeling Procedures The motion and wave modeling procedures described hereafter shall be applied, according to the indicated analysis purpose, riser configuration and vessel motion, as per TABLE 6C.

TABLE 6C - REQUIRED ANALYSIS PROCEDURE

Analysis Purpose

Vessel Motion Maximum Top and Bottom Tension,

Minimum Bending Radius, Minimum Riser Length

Bending Stiffener Verification and Dynamic Riser Top Region When

Installing

(a) Free hanging

SS or F(P)SO

EHMP & IWP or

DWP & IWP DWP & IWP

I - Dynamic Riser Configuration

(b) Others SS or F(P)SO DWP & IWP DWP & IWP

II - Installation (Static and Dynamic Pipes)

Installation vessel EHMP EHMP

Notes: 1) SS means semi-submersible vessel.

2) F(P)SO means a ship-like vessel.


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5.3.5.4.1 Equivalent Harmonic Motion Procedure (EHMP) The following steps shall be followed:

a) transfer the RAOs from the vessel center of movements to the riser top connection coordinates;

b) obtain the response spectrum for the movements of the connection by crossing the wave spectrum and RAOs for the riser connection;

c) determine the Rayleigh most probable maxima of motion displacements, for the connection movements;

d) determine the zero up-crossing period for the vertical movement response; e) assume, for the riser connection regular movements, the maxima amplitude

values as per paragraph c) above and period according to paragraph d) above; f) assume, for the regular movements of the riser connection, the same phase

values of the transferred RAOs in paragraph a), taken for the corresponding period of paragraph d).

Note: The above approach does not consider the direct wave action on the riser. 5.3.5.4.2 Design Wave Procedure (DWP) The following steps shall be followed:

a) transfer the RAOs from the vessel center of movements to the riser top connection coordinates;

b) obtain the response spectrum for the movements of the top connection by crossing the wave spectrum and RAOs for the riser top connection;

c) determine the Rayleigh most probable maxima of motion displacements and accelerations, for the connection movements;

d) determine the wave height (Hdesign) as the Rayleigh most probable maxima from Hs (significant wave height) as used to describe wave spectrum in paragraph b);

e) evaluate periods (Tdesign1 and Tdesign2), which associated with Hdesign, shall furnish, respectively, the maximum harmonic displacement and maximum harmonic acceleration, both calculated as per paragraph c); among the possible T design values, chose the closest value to the wave peak period (Tp); this procedure shall be carried out, at least, 2 times, depending on top connection motion: (1) the most critical between surge/sway and heave, (2) the most critical between roll and pitch.

5.3.5.4.3 Irregular Wave Procedure (IWP) This procedure is to be considered as a validation check of the results of the above-mentioned procedures. Therefore, only the most critical loading cases, shall be analyzed according to this method. For each pipe, a minimum number of 4 full irregular analyses shall be chosen by following criteria:

a) worst loading case for compression value; b) worst loading case for top tension; c) worst loading case for bending radius; d) worst loading case for bending stiffener design.


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Notes: 1) When considering the specification of the number of harmonic components to

describe wave spectra, a minimum number of 100 shall be considered. 2) The results coming from random analyses shall be statically processed in a way

to give consistent and reliable maximum values. When simulating the chosen loading cases, 3 options are considered valid:

a) to perform, at least 5, 30 minute simulations varying random seed for the

initial harmonic components phases; the significant wave height shall occur at least once in each simulation;

b) from simulated long time history (minimum 60 hours) of critical pipe top movement, select a minimum of 10, 5 minute windows to be analyzed;

c) to perform a 3 hour simulation. If the manufacturer is supplying a set of risers of the same structure which are to be connected to the same floating unit, purchaser might accept, if duly justified by the manufacturer, irregular wave analysis carried out for

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Petrobras N-2409-A2