ERD-43-15 (2)

Petroleum Development Oman

ENGINEERING REFERENCE DOCUMENT

ERD-43-15NOVEMBER 98

SPECIFICATION FOR POLYETHYLENE LINERSIN CARBON STEEL FLOWLINES AND PIPELINES

Petroleum Development Oman LLC (PDO) have published this Engineering Reference Document (ERD) for PDO employees and PDO nominated Contractors and Suppliers.

ERD-43-15 SPECIFICATION FOR POLYETHYLENE LINERS

NOVEMBER 1998 IN CARBON STEEL FLOWLINES AND PIPELINES

Do not use this copy of the ERD if the print-out date is before the latest issue date. The print-out date is on the bottom of every page. You can find the latest issue date for this ERD on the wall-chart ERD-00-01. Check the PDO-Intranet (DCS pages) for news about temporary amendments Printout date: 08 Apr. 23

SPECIFICATION FOR POLYETHYLENE LINERS ERD-43-15IN CARBON STEEL FLOWLINES AND PIPELINES NOVEMBER 1998

REVISION HISTORY

Revision Date Description0 November 1998 First Issue

Do not use this copy of the ERD if the print-out date is before the latest issue date. The print-out date is on the bottom of every page. You can find the latest issue date for this ERD on the wall-chart ERD-00-01. Check the PDO-Intranet (DCS page) for news about temporary amendments. Printout date: 08 Apr. 23



INSTRUCTIONS TO USER

Make sure this is the latest issue of this Engineering Reference Document (ERD). Refer to the Wall Chart ERD-00-01 for the last issue date.

Where this ERD refers to DEPs and International Standards, it refers to the issues that were in use when the author wrote this ERD. Exceptions are references to specific issues. If you use DEPs or International Standards with this ERD, make sure you use the correct issues.

Do not change this ERD without approval. Only the Custodian, the Corporate Functional Discipline Head (CFDH) Corrosion Engineering, who owns this ERD can give approval for changes. If you think the ERD is not correct, write your comments on a copy of the User Comment Form. The form is the last page of this ERD. Send the copy with your comments and personal details to DCS.

Author

OQEDate:

Custodian

OQEDate:

Functional Director ForEngineering

UEDDate



TABLE OF CONTENTS

REVISION HISTORY 2

INSTRUCTIONS TO USER.............................................................................................................3

1.0 INTRODUCTION...................................................................................................................3

1.1 SCOPE 31.2 APPLICABILITY................................................................................................................. 31.3 LANGUAGE AND UNITS OF MEASUREMENT.................................................................31.4 STANDARD DEFINITIONS................................................................................................31.5 SPECIAL DEFINITIONS....................................................................................................3

1.5.1 Acceptance criteria......................................................................................................31.5.2 Annulus………………………………………………………………………………………….31.5.3 Bell hole…………………………………………………………………………………………31.5.4 Butt fusion welding......................................................................................................31.5.5 Flanges....................................................................................................................... 31.5.6 Lot (number)...............................................................................................................31.5.7 Maximum Allowable Operating Pressure......................................................................31.5.8 Ovality......................................................................................................................... 31.5.9 PE liner....................................................................................................................... 31.5.10 Permeation..................................................................................................................31.5.11 Point of fusion.............................................................................................................31.5.12 Records...................................................................................................................... 31.5.13 Standard Dimension Ratio...........................................................................................31.5.14 Vent point....................................................................................................................31.5.15 Venting........................................................................................................................ 31.5.16 Visual examination......................................................................................................31.5.17 Raw Material Manufacturer..........................................................................................31.5.18 PE Pipe Supplier.........................................................................................................31.5.19 Rotational moulding.....................................................................................................31.5.20 Crude oil service..........................................................................................................31.5.21 Water service..............................................................................................................3

1.6 ACRONYMS...................................................................................................................... 3

ANSI................................................................................................................................................ 3

2.0 PURCHASING GUIDELINES................................................................................................3

2.1 GENERAL.......................................................................................................................... 32.2 PRESSURE RATING.........................................................................................................32.3 UV PROTECTION.............................................................................................................32.4 CONNECTIONS................................................................................................................32.5 PURCHASE ORDER INFORMATION................................................................................3

3.0 DESIGN................................................................................................................................ 3

3.1 INTRODUCTION...............................................................................................................33.1.1 Basis of design............................................................................................................3

3.2 PE LINER DESIGN PROCEDURE.....................................................................................33.2.1 Water service..............................................................................................................33.2.2 Liner design procedure................................................................................................3

3.3 VENTING........................................................................................................................... 3

4.0 MANUFACTURE................................................................................................................... 3

4.1 PIPE MATERIAL................................................................................................................34.2 FLANGE MATERIAL..........................................................................................................34.3 ROTATIONAL MOULDED SPOOLS..................................................................................3




4.4 FINISH AND WORKMANSHIP...........................................................................................3

5.0 QUALITY PROGRAM............................................................................................................3

5.1 QUALITY MANUAL............................................................................................................35.2 PROCESS AND QUALITY CONTROL REQUIREMENTS..................................................35.3 QUALITY CONTROL EQUIPMENT....................................................................................3

5.3.1 General....................................................................................................................... 35.3.2 Dimensional measuring equipment..............................................................................35.3.3 Pressure measuring devices........................................................................................3

5.4 QUALITY CONTROL TESTS.............................................................................................35.4.1 Conditioning................................................................................................................35.4.2 Test conditions............................................................................................................35.4.3 Test requirements.......................................................................................................35.4.5 Retest and rejection.....................................................................................................35.4.6 Failure......................................................................................................................... 3

5.5 INSPECTION AND REJECTION........................................................................................35.5.1 Inspection by the Principal...........................................................................................35.5.2 Injurious defects..........................................................................................................3

5.6 QUALITY CONTROL RECORDS REQUIREMENTS..........................................................35.6.1 Purpose...................................................................................................................... 35.6.2 Records control...........................................................................................................35.6.3 Records to be maintained and supplied by pipe supplier..............................................3

6.0 EQUIPMENT MARKING........................................................................................................3

7.0 HANDLING AND STORAGE.................................................................................................3

7.1 STORAGE......................................................................................................................... 37.2 HANDLING........................................................................................................................ 37.3 TRANSPORTATION..........................................................................................................3

8.0 INSTALLATION..................................................................................................................... 3

8.1 GENERAL.......................................................................................................................... 38.2 LINER FABRICATION & BUTT FUSION WELDING...........................................................38.3 END FLANGES AND IN-LINE FLANGED JOINTS.............................................................38.4 VENT POINT ASSEMBLIES..............................................................................................38.5 SUPERVISION AND INSPECTION....................................................................................3

8.5.1 Inspection notice.........................................................................................................38.5.2 Inspection of liner materials.........................................................................................38.5.3 Compliance................................................................................................................. 3

8.6 DOCUMENTATION...........................................................................................................3

9.0 PRE-COMMISSIONING........................................................................................................3

9.1 GENERAL.......................................................................................................................... 39.2 PROCEDURE....................................................................................................................3

10.0 OPERATION......................................................................................................................... 3

10.1 GENERAL.......................................................................................................................... 310.2 NORMAL OPERATION......................................................................................................310.3 DE-PRESSURISATION.....................................................................................................310.4 MONITORING................................................................................................................... 310.5 RECOVERY PLAN.............................................................................................................3

11.0 REFERENCES...................................................................................................................... 3

11.1 COMPANY STANDARDS..................................................................................................311.2 NATIONAL STANDARDS..................................................................................................311.3 INTERNATIONAL STANDARDS........................................................................................3

9969 THERMOPLASTIC PIPES – DETERMINATION OF RING STIFFNESS............................3



APPENDIX A - BUTT FUSION WELDING QUALIFICATION............................................................3

APPENDIX B - SWELL TEST PROCEDURE...................................................................................3

APPENDIX C - COLLAPSE EQUATION..........................................................................................3

APPENDIX D - PE MATERIAL PROPERTIES.................................................................................3

APPENDIX E - PURCHASE ORDER INFORMATION......................................................................3

APPENDIX F - PE LINER DESIGN DATA SHEET...........................................................................3

APPENDIX G - PE MATERIAL PROPERTIES.................................................................................3

APPENDIX H - INSTALLATION GUIDELINES.................................................................................3

ERD USER-COMMENT FORM........................................................................................................3




1.0 INTRODUCTION

1.1 SCOPE

This ERD defines the minimum technical requirements for the design and procurement of polyethylene (PE) liners for onshore water, oil and gas applications and provides guidelines for the installation, commissioning and operation of onshore PE lined Carbon Steel flowlines and pipelines.

1.2 APPLICABILITY

This ERD is intended for use in the design, procurement, manufacturing, transport, installation commissioning and operation of polyethelene liners. Applications are for flowlines and pipelines, both buried and above ground, for oil, gas and water service.

If this ERD is applicable to the work that you do, you shall obey its instructions. You shall get approval, in writing, from the Custodian, the CFDH of Corrosion Engineering who owns this ERD, before you use procedures other than those that this ERD specifies.

1.3 LANGUAGE AND UNITS OF MEASUREMENT

You shall use the English language and the International System (SI) units of measurement in all documents and drawings. Where the SI unit is a conversion of a manufactured dimension, you can put the original dimension, in brackets, after the SI units. For example, 50 mm (2in) pipe.

1.4 STANDARD DEFINITIONS

The list that follows tells you the meaning of some words applicable to all ERDs: Company: Petroleum Development Oman LLC. Principal: The person or organisation that specifies the requirements in a contract and pays the

contractors and vendors for their services, materials and equipment. Contractor: The person or organisation that supplies the company with services.

In the context of this ERD the Contractor is the person or organisation that purchases the PE pipe, installs the PE liner in the carbon steel pipe and commissions the pipeline or flowline.

Vendor: The person or organisation that supplies the company with materials and/or equipment. Discipline: A specific set of technical knowledge and skills. Corporate Functional Discipline Head (CFDH): The person responsible for a discipline in the

Company. The CFDH Corrosion Engineering owns this ERD. User: The person or organisation that reads, and uses the information, in this and other ERDs. Shall: tells you that you must obey an instruction. Should: tells you what the Principal recommends. May: tells you a possible procedure.

1.5 SPECIAL DEFINITIONS

The list that follows tells you the special meaning of some words in this ERD:

1.5.1 Acceptance criteria

Defined limits placed on characteristics of materials, products, or services.

1.5.2 Annulus

Space between the PE liner and the carbon steel outer pipe.

1.5.3 Bell hole

Excavated area allowing access to a buried carbon steel pipeline for insertion of the PE liner.Do not use this copy of the ERD if the print-out date is before the latest issue date. The print-out date is on the bottom of every page. You can find the latest issue date for this ERD on the wall-chart ERD-00-01. Check the PDO-Intranet (DCS pages) for news about temporary amendments Printout date: 08 Apr. 23


1.5.4 Butt fusion welding

A fusing of polyethylene materials that entails squaring and aligning the pipe materials, heating the pipe ends, pressuring the two aligned ends together and cooling for a predetermined time, all as specified by the qualified procedure which results in a joining of two pipe materials. The joint will exhibit a hydrostatic strength equal to the parent pipe.

1.5.5 Flanges

Steel raised face flanges with bolt circle per ANSI B 16.5. Incorporates use of PE flange and metallic backup ring.

1.5.6 Lot (number)

For PE pipe a ‘lot’ is defined as being all pipes produced from the same base polymer batch with the same diameter and wall thickness, up to a maximum number of 200 pipe lengths or 2000 m of coiled pipe. For moulded or machined PE flanges a ‘lot’ is defined as being all flanges produced from the same base polymer batch with the same dimensions, up to a maximum number of 200. For rotational moulded PE spools a lot is defined as 20 spools. A lot number is a unique code to maintain traceability.

1.5.7 Maximum Allowable Operating Pressure

Pressure which the carbon steel pipe may be operated at in actual service.

1.5.8 Ovality

This is a measurement of the deflected set in a cross section of pipe and is expressed as a percentage. It is measured by taking the maximum measured diameter minus the minimum measured diameter (the out of roundness value) and dividing that sum by the average measured diameter and multiplying that resultant by 100.

1.5.9 PE liner

Internal PE pipe for corrosion protection of carbon steel pipelines or flowlines. A PE liner consists of a number of PE pipe lengths which are fused together and inserted into sections of new or existing carbon steel pipelines and flowlines. The Carbon Steel pipe provides the pressure containment; the PE liner the corrosion protection. At the ends of the sections the liners are terminated by PE flanges.

1.5.10 Permeation

Diffusion of liquid and gas through the PE liner under the influence of pressure and temperature.

1.5.11 Point of fusion

The end of pipe which is available for trimming, heating, and pressing together during the heat fusion process.

1.5.12 Records

Retrievable information.

1.5.13 Standard Dimension Ratio




A specific ratio of the average specified outside diameter to the minimum specified wall thickness (OD /h) for outside diameter-controlled plastic pipe, the value of which is derived by adding one to the pertinent number selected from the ANSI Preferred Number Series 10, (ANSI Z17.1).

1.5.14 Vent point

Hole in the carbon steel outer pipe to allow the release of gas accumulated in the annulus.

1.5.15 Venting

The release of gas accumulated in the annulus.

1.5.16 Visual examination

Examination of parts and equipment for visible defects in material and workmanship.

1.5.17 Raw Material Manufacturer

Company that provides the raw PE material (granulate) to the PE pipe supplier.

1.5.18 PE Pipe Supplier

Company that extrudes the PE liner pipe.

1.5.19 Rotational moulding

Production technique in which a PE lined spool is produced by heating and rotating a carbon steel spool with PE powder inside. The PE powder melts and forms a liner on the surface of the carbon steel pipe.

1.5.20 Crude oil service

Fluids with crude oil fraction of more than (or equal to) 1 vol%.

1.5.21 Water service

Fluids with less than 1 vol% crude oil.

1.6 ACRONYMS

ANSI American National Standards InstituteAPI American Petroleum InstituteASTM American Society for Testing and Materialsh Minimum specified wall thicknessID Inside DiameterISO International Standards OrganisationMAOP Maximum Allowable Operating PressureOD Outside DiameterPE PolyethyleneSDR Standard Dimension RatioHDB Hydrostatic Design Basis



2.0 PURCHASING GUIDELINES

2.1 GENERAL

This section provides guidelines for enquiry and purchase of PE liner pipe. The base specification and grade of PE, to satisfy the design criteria in Section 3, the minimum material property requirements in section 4 and process conditions stated in the Purchase Order (Appendix E), shall be determined by the Contractor.

2.2 PRESSURE RATING

Material for pipe for PE liners has no pressure rating requirements. Instead section 3 of this ERD shall be used by the Contractor in conjunction with the process design conditions specified by the Principal to provide the most economic combination of PE material grade and wall thickness, subject to the minimum material properties specified in Table 2 (section 4.1).

2.3 UV PROTECTION

All PE pipe and fittings supplied to this specification shall be stabilised against degradation by UV-light in accordance with standard practices by a minimum of 2% (by mass) of Carbon Black (ASTM D3350).

2.4 CONNECTIONS

Liner pipe supplied to this specification shall be joined by butt fusion welding. Connections between PE lined carbon steel pipes shall be flanged. No other joining methods shall be permitted unless agreed with the Company.

All joining procedures and operators shall be qualified in accordance with Appendix A of this specification prior to the commencement of production.

2.5 PURCHASE ORDER INFORMATION

The Principal shall provide to the Contractor the information in Appendix E as part of the purchase order.




3.0 DESIGN

3.1 INTRODUCTION

This section covers the design of PE liners for Carbon Steel flowlines and pipelines. The design specifies, amongst others, the minimum wall thickness of the PE pipe. PE liners often have to be tailor-made to the application, i.e. non-standard dimensions are used.

The liner OD shall be determined by the Contractor, taking into account both the ID of the Carbon Steel pipe and the requirements of the selected installation technique.

The installed liner wall thickness shall be determined by the Contractor and shall comply with the requirements in this specification. The Contractor shall propose to the Principal the dimensions of PE pipe to be purchased, demonstrating full compliance with this specification.

3.1.1 Basis of design

The wall thickness of the liner is determined by one of the following three requirements:

(a) The practicalities of installation: To ensure that the PE pipes are robust, can be joined by butt fusion welding, and pulled into the Carbon Steel pipe, a minimum wall thickness is required. This requirement typically pertains to water service (section 3.2.1). The Contractor shall recommend the minimum wall thickness for handling and installation purposes

(Note: experience in PDO with 3" water injection lines has shown that a minimum wall thickness of approximately 6 mm is required for reliable fusion welding and to avoid failures due to weld penetration).

(b) Liner stability (buckling resistance): When high annulus pressures are not anticipated, the liner stability will be determined mainly by swelling and thermal expansion (including high temperatures in non flowing conditions). This requirement typically pertains to well stabilised crude oil (section 3.2.2). The Contractor shall calculate a wall thickness requirement for buckling complying with Appendices B and C of this specification (and with the minimum collapse pressure requirement of 3 bar; see below).

(c) Liner collapse: pertains mainly to live crude (multi-phase lines or lines in which gas break-out can occur) or to gas and aims to prevent liner collapse due to annulus gas in combination with liner instability due to swelling stresses. Hydrocarbon liquids and gases permeate through PE liners, accumulate in the annulus between the liner and the carbon steel pipe and can cause collapse in case of pressure fluctuations or depressurisation.

If the liner wall thickness is sufficient to withstand an annulus pressure equal to the pipeline bore pressure (MAOP) the design is intrinsically safe against collapse. However, experience has shown that this requirement is over-conservative and that a smaller collapse pressure is acceptable if the annulus volume during normal operation (i.e. not during installation or after depressurisation) is minimised and vented.

The contractor shall therefore calculate a wall thickness requirement for collapse (Appendix C) using the pressure fluctuation during normal operation as the minimum required collapse resistance of the PE liner in combination with liner instability due to swelling.

For all crude oil applications a minimum wall thickness to withstand a Collapse Pressure of 3 bar is required (whilst taking swelling stresses into account; Appendix C).

(Note: In the past liners have been used mainly for small diameter pipelines and flowlines and have been designed to have a collapse pressure equal to the normal operating pressure or to have a minimum collapse pressure of 10 bar. However, this conservative approach inhibits the application of PE liners for large diameter crude oil lines. Considering the excellent experience with thick walled liners and the success in PDO with thin walled liners in large diameter lines in two ongoing field trials (with live crude and continuous venting) started



late 1996, a minimum collapse pressure of 3 bar has been adopted. The 3 bar collapse pressure is considered to result in practical liner thickness for large diameter lines, whilst at the same time limiting the risk of collapse to an acceptable level).

3.2 PE LINER DESIGN PROCEDURE

3.2.1 Water service

A pipeline may be considered in water service for the purpose of this specification if the total hydrocarbon fraction does not exceed 1 vol.% of total fluids and no gas phase is present. In water service, swelling due to hydrocarbons or collapse by expanding annulus gas are not an issue. The wall thickness is determined by the practicalities of the installation. The maximum temperature for the use of PE liners in water service is 70 C.

3.2.2 Liner design procedure

In order to determine the minimum required wall thickness for the PE liner the data sheet in Appendix F shall be filled in as follows:

Step 1. Determine the OD of the liner pipe taking into account both the ID of the Carbon Steel pipe and the requirements of the installation technique.

Step 2. Specify the minimum wall thickness for handling and installation purposes to satisfy requirement 3.1.1(a).

Step 3. Determine the PE Modulus and swelling for the service conditions (fluid composition, maximum operating temperature; see Appendix D for guidance).

Step 4. Calculate with Appendix C the required wall thickness for liner stability to satisfy requirement 3.1.1(b) assuming 3 bar to be the minimum collapse pressure (for well stabilised crude).

Step 5. For live crude (crude where a gas phase is present or where gas break out can occur over the pipeline length): The minimum collapse pressure is equal to the maximum continuous cyclic pressure variation during normal service with a minimum of 3 bar.

Step 6. Calculate the required wall thickness for the Collapse Pressure in Step 5 using Appendix C taking into account swelling.

Step 7. The required wall thickness is the higher of the thicknesses resulting from the requirements under 2, 4 and 6.

The Contractor shall supply to the Principal the liner design sheet in Appendix F as part of the tender documentation.

3.3 VENTING

Every PE lined pipeline and flowline shall incorporate vent points. The minimum number of vent points shall be one on each flanged end of a section of lined pipe. The vent points have three functions:

To vent the (ambient) gas from the pipe/annulus during installation. To vent the permeated fluids accumulated in the annulus to prevent collapse. To allow monitoring of the integrity of the PE liner during the service life.

Vents can be designed to be:

Continuously closed (plugged). Valved (closed or open during normal operation).

For water injection lines venting is not necessary and therefore vents are normally plugged. Lines transporting liquid hydro-carbons with H2S concentrations lower than 50 ppm can have continuously open vents (vents shall be valved in order to be able to close the annulus in case of liner leakage or collapse). For gas transport and for H2S concentrations of 50 ppm and higher, vents will have to be opened and closed on a periodic basis (see section 10)




4.0 MANUFACTURE

4.1 PIPE MATERIAL

Polyethylene liner pipe shall be produced and classified in accordance with a recognised Industry Standard (API or ISO), the grade being selected by the Contractor to meet the specified design, installation and operational requirements. The Contractor shall be responsible for identifying any supplementary requirements, such as special dimensional tolerances, necessary to meet the liner design criteria.

Liner pipe furnished to this specification shall be produced by extrusion. The inclusion of rework materials during pipe manufacture shall not be permitted. The form of supply, whether as cut lengths or coils shall be as stated on the Purchase Order.

Minimum properties for the PE liner material are given in Table 2. The Contractor shall complete the data sheets in Appendix G and supply these as part of the tender documentation.

Table 2 - Minimum Properties for Polyethylene Liner Pipe

Property Test Method Minimum requirement

Density (g/cm3) ASTM D1505 > 0.941Melt index

(g/10min; 190o C, 2160 gr load)

ASTM D1238 < 0.2

Modulus (MPa; 50 mm/min; 20 C) ASTM D638 >750Tensile strength (MPa; 50 mm/min) ASTM D638 >18Environmental stress crack resistance (Condition C, 192 hours)

ASTM D1693 Failure less than 20%

Hydrostatic design basis

(MPa at 20o C, 20 years)

ASTM D2837 > 8

Oxygen Induction Temperature

(at 200o C)

ASTM D3895 > 150 minutes

4.2 FLANGE MATERIAL

PE flanges shall be moulded or machined from extruded material and shall be from the same PE grade as the pipe. Other PE grades with similar minimum material properties may be used after agreement by the Principal. The wall thickness of the PE flanges shall be equal to the wall thickness of the pipe. Flared flanges are only permitted for limited lengths, which can not be fitted with fused flanges, and after explicit approval of the Principal.

4.3 ROTATIONAL MOULDED SPOOLS

Rotational moulded spools are allowed after agreement by the Principal. The PE grade used shall have minimum material properties as listed in Table 2 unless otherwise agreed with the Principal.The wall thickness of the PE liner in the spools preferably shall be equal to the minimum wall thickness determined in Section 3 (note: there is a maximum wall thickness which can be rotationally moulded). There shall be no reliance on adhesion of the PE to the steel surface. In case of live crude or gas service, vents are required on the spool pieces.

4.4 FINISH AND WORKMANSHIP

Cut pipe ends shall be plain and square. Cut edges shall be clean and without ledges, shaving tails, burrs or cracks. The interior of the pipe shall be blown or washed clean of cuttings and shavings.



The interior and exterior of the pipe shall be uniform in finish without voids, cracks, crazing, foreign inclusions or any scratches deeper than 5% of the nominal wall thickness.




5.0 QUALITY PROGRAM

5.1 QUALITY MANUAL

The pipe supplier shall maintain a quality manual which describes the quality program. The Manual shall conform to the requirements of ERD 84-02. All prior revisions shall be retained for a period of not less than five years.

5.2 PROCESS AND QUALITY CONTROL REQUIREMENTS

The pipe supplier shall institute and maintain a documentation programme to assure communication of approved manufacturing and inspection procedures to qualified receiving, manufacturing and quality control personnel, and their respective supervisory personnel. The following procedures shall be submitted to the Company for review and approval:

a. Raw material acceptanceb. Extrusion proceduresc. Pipe manufacturing practicesd. Welding procedures and qualificationse. Inspection and test proceduresf. Acceptance criteria

5.3 QUALITY CONTROL EQUIPMENT

5.3.1 General

Equipment used to inspect, test or examine material or other equipment shall be identified, controlled, calibrated and adjusted at specified intervals in accordance with documented pipe supplier instructions, and consistent with referenced industry standards to maintain the accuracy required by this specification.

5.3.2 Dimensional measuring equipment

Dimensional measuring equipment shall be controlled and calibrated by the pipe supplier's written specification.

5.3.3 Pressure measuring devices

Test pressure measuring devices shall be either pressure gauges or pressure transducers. All pressure measuring devices shall be calibrated to a certified standard annually.

5.4 QUALITY CONTROL TESTS

5.4.1 Conditioning

5.4.1.1 Quality control testing

Unless otherwise specified, all QC specimens shall be conditioned for a minimum of 4 hours prior to test in air or 1 hour in water at 23 ± 2 °C. The specimens shall be tested at 23 ± 2 °C without regard to relative humidity.

5.4.1.2 Referee testing

When conditioning is required for referee tests, or in cases of disagreement, the specimens shall be conditioned in accordance with Procedure A of ASTM Method D618 at 23 ± 2 °C and at an agreed



level of relative humidity for not less than 40 hours prior to test. Tests shall be conducted under the same conditions of temperature and humidity unless otherwise specified by the Company.

5.4.2 Test conditions

Tests shall be conducted at the Standard Laboratory temperature of 23 ± 2 °C unless otherwise specified in the test methods or in this specification. In case of disagreement, the tolerance shall be ± 1 °C.

5.4.3 Test requirements

Tests shall be carried out on pipe, moulded/machined flanges or rotational moulded spools once per lot to determine the material properties (and following the procedures) listed in Table 2. The results of the tests shall be within 5% of the material property data (density and carbon black content within 0.5%) provided by the pipe supplier before start of production. Alternatively, for short production runs or a small number of flanges or spools (less than as defined for a lot), material data supplied by the raw material manufacturer may be accepted after agreement by the Principal.

In addition, tests listed in Table 3 shall be carried out.

5.4.5 Retest and rejection

When the pipe, flange or rotationally moulded spool fails to meet the specification requirements of any test, additional tests shall be made on the products produced, back to the previous acceptable results. The pipe, flange or rotationally moulded spool produced in the interim that does not pass the requirements shall be rejected.

Table 3 - Requirements for production tests on PE liner pipe

Property ASTM Method

Acceptance criteria Frequency

Outside diameterWall thickness

D2122D2122

API 15LE Table 3API 15LE Table 3

Once every hour, once every pipe or once every coil, whichever is less frequent

Burst Pressure D1599 Minimum of 90% of burst pressure specified by the pipe supplier (Appendix G)

Once per lot

Out of roundness D2122 < 5% Once per lot

5.4.6 Failure

Pipe failure is any continuous loss of pressure caused by the transmission of the test liquid through the body of the pipe under test: ballooning, bursting, seepage or weeping.

5.4.6.1 Ballooning

Any abnormal localised expansion of a pipe specimen while under internal hydraulic pressure.

5.4.6.2 Bursting

Failure by a break in the pipe with immediate loss of test liquid and continued loss at essentially no pressure.

5.4.6.3 Seepage or weeping




Failure that occurs through microscopic breaks in the pipe wall, frequently only at or near the test pressure. At lower pressures, the pipe may carry liquids without evidence of loss of the liquids.

5.5 INSPECTION AND REJECTION

5.5.1 Inspection by the Principal

All Quality Control tests shall be witnessed by a Company appointed representative at the start of production and monitored thereafter at the discretion of the Company.

5.5.2 Injurious defects

Injurious defects are those which adversely affect the service life of the pipe such as foreign inclusions, kinks, visible cracks, or contamination with foreign materials and any other defects and imperfections reducing the wall thickness below minimum tolerance listed in the dimensional Tables in API 15LE or ISO 4427, as specified in the Purchase Order. Pipe, flanges and rotationally moulded spools with injurious defects shall be rejected.

5.6 QUALITY CONTROL RECORDS REQUIREMENTS

5.6.1 Purpose

The quality control records required by this specification are necessary to substantiate that all pipe made to meet this specification conform to the specified requirements.

5.6.2 Records control

Quality control records required by this specification shall be legible, identifiable, retrievable and protected from damage, deterioration or loss.

Quality control records required by this specification shall be retained by the pipe supplier and Contractor for a minimum of five years following the date of manufacture.

All quality control records required by this specification shall be signed and dated by the pipe supplier's designated authorised person.

5.6.3 Records to be maintained and supplied by pipe supplier

1. Quality manual in accordance with 5.1.2. Quality control test results in accordance with 5.4.3. Design and material qualification data in accordance with section 3.1, 3.2 and 5.4.3, and the

Appendices E, F, G.4. All procedures utilised by the pipe supplier in the process of fulfilling the order.6. Quality assurance records for all materials supplied by the pipe supplier.



6.0 EQUIPMENT MARKING

Liner pipe manufactured in conformance with this specification shall be marked by the pipe supplier as specified.

The required markings shall be paint-stencilled or printed on the outside surface of each length or coil of pipe at intervals of not more than 1.5 m. Indentation marking may be used provided:

1. The marking does not reduce the wall thickness to less than the minimum value for the pipe.2. It is demonstrated that these marks have no effect on the long-term strength of the pipe.

The markings on each length or coil of pipe shall include in any sequence:

1. Pipe supplier's name or trademarks2. Base specification shown on purchase order, (e.g. API 15LE, ISO 4427)3. Pipe OD and wall thickness4. Date of manufacture5. SDR6. Pipe supplier's lot number7. Appropriate material code used by the pipe supplier to uniquely identify the material8. HDB at 20ºC and 20 years.9. Design temperature in (C)10 Modulus (MPa, at design temperature, determined to ISO 9969)11. Additional markings, except pressure ratings, as agreed upon between pipe supplier and

Principal




7.0 HANDLING AND STORAGE

7.1 STORAGE

All liner pipe shall be packed and stored in accordance with a procedure agreed by the Company. For periods longer than 3 months, polyethylene pipe shall be stored under cover with adequate protection from direct sunlight to avoid UV degradation and/or deformation. If the pipe has to be stored in the open air before, during or after shipment, it shall be suitably protected from environmental contamination. The packing shall avoid ingress of moisture or dirt to the inside of the pipe.

Coils shall be stored stacked flat one on top of the other. Straight lengths shall be stored on horizontal racks giving support to prevent damage to the pipe. In either form, PE pipe shall not be allowed to come into contact with hot water or steam pipes and shall be kept away from hot surfaces.

7.2 HANDLING

All pipe shall be cleaned, dried, packed, handled and transported so as to arrive at its destination without distortion or damage. Polyethylene is a tough, resilient material which may be handled easily. However, although generally resistant to abrasion, it is softer than metals and prone to damage by sharp edged objects. Such practices as dragging pipe or coils over rough ground shall therefore be avoided. If, due to unsatisfactory storage or handling, a pipe is damaged or "kinked", the damaged pipe shall be rejected.

7.3 TRANSPORTATION

The minimum requirements for transportation shall be as specified in the following Recommended Practices:

API RP 5L1 for railroad transportation API RP 5LW for marine transportation

Pipe transported by sea shall not be shipped as deck cargo.



8.0 INSTALLATION

8.1 GENERAL

This section outlines general requirements for field installation of PE liners in carbon steel pipelines and flowlines. Detailed guidelines are given in Appendix H. The PE liner consists of a number of PE pipe lengths which are fused together, pressure tested and inserted into sections of pre-welded or existing carbon steel pipelines. The qualification and inspection of fusion welded PE joints is specified in Appendix A of this specification.

Installation of PE liners shall be undertaken only by Company approved Contractors working in accordance with written procedures and method statements approved by the Company. The procedures shall be detailed in a Quality Plan and shall cover as a minimum the following areas:

Materials handling and control Site and pipe preparation Liner prefabrication Installation Testing and inspection Pre-commissioning

No work shall be commenced until the relevant procedures have been approved. At least two weeks should be allowed for review of documentation submitted to the Company.

Requirements for leak and hydrotesting of the carbon steel line, the PE liner as well as the lined carbon steel line are given in Section 9.

8.2 LINER FABRICATION & BUTT FUSION WELDING

Field joining of liner pipe shall be by butt fusion welding techniques. Qualification of procedures and operators shall be in accordance with Appendix A. A full time inspector shall be dedicated by the Contractor for every welding machine. A check list shall be used during fusion welding and all relevant welding parameters shall be measured and recorded (including the identification of the welder) for each and every fusion weld. Quality control parameters shall be defined including the full circumferential fusion of the removed external roll-back weld bead at every joint (removed by a trimming tool). To confirm that correct machine parameters are maintained, daily test samples (strips) shall be taken of a butt welded joint and subjected to a 180º reverse bend test without failure. The test shall also be conducted when machine settings are altered. The bend test shall be in general accordance with ASME IX section QW-466.

8.3 END FLANGES AND IN-LINE FLANGED JOINTS

Connections between PE lined pipes and CS piping shall be flanged. No other joining methods shall be permitted unless agreed with the Principal. The design of the PE lined flanges shall be raised face with spacer/backing rings unless otherwise agreed with the Principal.

8.4 VENT POINT ASSEMBLIES

Every PE lined pipeline and flowline shall incorporate vent points. The minimum number of vent points shall be one on each flanged end of a section of lined pipe. Vent holes shall be designed such that no extrusion of the PE liner will occur. For larger diameter lines, vent discs with multiple holes or wire screens may be used. Vent holes shall not be larger than 3 mm in diameter. All vents shall be valved (except for water service where vents can be plugged) and shall have a "snorkel" to prevent ingress of dirt, moisture and/or air.

The design of the vent point assembly shall be agreed with the Principal.




8.5 SUPERVISION AND INSPECTION

The Contractor shall ensure that all stages of the work are adequately supervised and that suitably qualified and experienced inspection personnel are used to carry out the inspection requirements detailed in the Quality Plan and individual procedures. Inspectors employed by the Contractor shall be subject to approval by the Company.

8.5.1 Inspection notice

Where the Inspector representing the Principal desires to inspect the pipes and/or flanges, or witness quality control tests, a minimum of 48 hours notice by the Contractor shall be given of the time at which the installation is to be made.

Installation, fusion welding or testing procedures required to be reviewed by the Principal shall be submitted by the Contractor a minimum of two weeks prior to the commencement of installation, unless an earlier date is specified in the Contract Document.

8.5.2 Inspection of liner materials

8.5.2.1 General

Material which shows injurious defects on site inspection or which proves to be defective when properly applied in service may be marked and rejected and the Contractor so notified.

8.5.2.2 Defects

a) Scratches in pipe: surface scratches and nicks in PE pipes may not exceed a depth of 5% of the nominal PE wall thickness.

b) Scratches in flanges: PE flange surfaces shall be free of scratches and nicks

c) Dents: the maximum depth shall be the smaller of 6.5 mm or 2% of the pipe OD.

8.5.2.3 Repair of defects

Repair of defects in any form is prohibited. Pipe lengths with defects exceeding the specification under a-c in this paragraph shall be discarded and marked as rejects.

8.5.3 Compliance

The Contractor is responsible for complying with all of the provisions of this specification. The Principal may make any investigation necessary to satisfy himself of compliance by the Contractor and may reject any material that does not comply with this specification.

8.6 DOCUMENTATION

The Contractor shall be responsible for maintaining, fusion welding, inspection, test and as-built documentation during installation and compiling a package of hand-over documentation on completion of the work. The records shall comply with Article 18 of Pipeline Construction Specification PCS-01, unless these are superseded by specific contract provisions agreed with the Company.



9.0 PRE-COMMISSIONING

9.1 GENERAL

The Contractor shall be responsible for the commissioning of the lined pipeline and shall hand-over to the Principal documentation with a detailed commissioning procedure before starting installation.

9.2 PROCEDURE

In the pre-commissioning phase the pipeline or flowline shall be hydrotested in accordance with the relevant pipeline code before the installation of the PE liner. The PE liner itself shall be leak tested before insertion. After liner insertion, the PE lined carbon steel line shall be hydrotested in accordance with the relevant pipeline code. During hydrotesting, temperature and pressure shall be recorded continuously unless otherwise agreed with The Principal.

During the final hydrotest the pressure shall be increased first to 3 times the PE pipe free-standing pressure rating with all vents open to allow annular fluids to escape. If all fluids have escaped or after one hour, which ever takes longer, the pressure shall be increased to the required hydrotest pressure.

At the end of the hydrotest the vents shall all be closed whilst the line is still under pressure. Two to four weeks after commissioning all vents shall be opened and closed again to allow fluids which may have permeated through the annulus to the vents to escape as well as to check whether any liner defects have developed (e.g. through creep of the PE liner).




10.0 OPERATION

10.1 GENERAL

Before commissioning the Contractor shall develop procedures and assign responsibilities for the operation phase covering:

Normal operation De-pressurisation Start-up Monitoring Recovery after collapse

10.2 NORMAL OPERATION

In order to limit the annular pressures and annular volumes in hydrocarbon services, vents shall be left open continuously or opened at regular time intervals to bleed off the annulus.

In case of manually operated valves the amount of fluids and gas which escapes during bleeding-off shall be measured in order to optimise the bleed-off frequency.

Venting of sour (H2S containing) gas may present an operational hazard. PDO's "Operations standards and practices" recognises the following 3 categories:

0-49 ppm in the gas phase: Sweet facility50-499 ppm in the gas phase: Low risk sour facility500+ ppm in gas phase: High risk sour gas

For liquid hydrocarbons and H2S levels of less than 50 ppm continuous venting is allowed. When the H2S levels are 50 ppm or higher, vents have to be closed during normal operation and appropriate safety procedures should be followed during routine venting.

Initially venting during normal operations shall be done in monthly intervals and the venting operations shall be recorded in a dedicated venting log (e.g. in Pacer-CM), with date, duration, purpose and a qualitative estimate of the amount of gas discharged. For large diameter and/or long lines, the amount of gas vented shall be measured accurately during a limited period and over a limited section in order to be able to make a quantitative assessment of required venting frequencies. The requirement for monthly venting may be revised when the amount of gas vented is negligible.

10.3 DE-PRESSURISATION

Before a de-pressurisation all vents shall be bled-off and left open. During pressurisation all vents shall be open to allow fluids and gasses to escape. After starting up all vents shall be closed (unless it was decided to operate the line with vents open).

10.4 MONITORING

The Principal shall develop and implement a condition monitoring plan for the PE liner including the monitoring of pressure drops (to confirm liner collapse) and regular venting of the annulus to establish leaks.

The amount of annular fluids which is bled-off shall be monitored on a regular basis in order to assess whether there are any problems with the integrity of the liner.

All monitored data shall be loaded into PDO's corrosion management system PACER-CM for analysis and to be able to revise the plan based on the monitored data.



In case the pressure in the annulus builds up quickly to the bore pressure as well as the annular fluids keeps on bleeding off, the technical integrity of the liner is suspect. This should immediately be reported to the Asset Owner. A leaking liner does not necessarily imply that there is a serious corrosion threat in the short term, however, shut-in/down and start up procedures will have to be adapted. A long term monitoring plan as well as a recovery plan has to be developed.

10.5 RECOVERY PLAN

The Contractor shall develop a generic recovery plan in case of a leaking or collapsed liner.




11.0 REFERENCES

In this ERD, reference is made to the following publications:

NOTE: Unless specifically designated by date, the latest edition of each publication shall be used, together with any amendments, supplements, revisions thereto.

11.1 COMPANY STANDARDS

ERD-00-02 Technical Authorities System ERD 00-02ERD-84-02 Quality Assurance Specification for Engineering WorksPCS-01 Pipeline Construction Specification

11.2 NATIONAL STANDARDS

ANSI:B 16.5 Pipe Flanges and Flanged FittingsZ17.1 ANSI Preferred Numbers

ASTM:D638 Test method for tensile properties of plasticsD1238 Test Method for Flow Rates of Thermoplastics by Extrusion PlastometerD1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD1599 Test Method for Short-Time, Hydraulic Failure Pressure of Plastic Pipe, Tubing and FittingsD1693 Standard Test Method for Environmental Stress Cracking of Ethylene PlasticsD2122 Determining Dimensions of Thermoplastics Pipe and FittingsD2657 Heat Joining Polyolefin Pipe and FittingsD2837 Obtaining Hydrostatic Design Basis for Thermoplastic Pipe MaterialsD3035 Standard Specification for Polyethylene (PE) Plastic Pipe (DR-PR) Based on Controlled

Outside DiameterD3350 PE Plastic Pipe and Fitting Material D3895 Standard Test Method for Oxidative Induction Time of Polymeric Materials by Differential

Scanning Calorimetry

API:15 LE Recommended Practise for Polyethylene Linepipe and FittingsRP 5L1 Recommended Practice for Railroad Transportation of LinepipeRP 5LW Recommended for Transportation of Linepipe on Barges

and Marine Vessels

ASME Boiler pressure vessel code – welding & brazing qualification

11.3 INTERNATIONAL STANDARDS

ISO:4427 Polyethylene (PE) pipes for Water Supply – Specifications

9969 Thermoplastic pipes – Determination of ring stiffness



APPENDIX A - BUTT FUSION WELDING QUALIFICATION

A.1 SCOPE

This appendix covers the minimum requirements for the qualification of butt fusion welding procedures and butt fusion welding operators for both shop and field welding of PE liner pipe.

A.2 PROCEDURES

Welding of PE liner pipe shall be carried out by the butt fusion process, as defined under ASTM D2657, Technique II.

The Contractor shall prepare a detailed procedure for each type and size of joint to be welded. Separate procedures shall be prepared for shop and site welding, and similarly, for the welding of pipe and of fittings. The procedures shall be qualified for each project as required in Section A.3.

Each butt fusion welding procedure shall detail the following information:

Welding equipment type, model and unique identification number Material grade and pipe supplier Pipe/fitting dimensions at the joint (diameter and wall thickness) Welding sequence Essential parameters to be controlled as detailed by the welding equipment operating manual,

separately for both the pre-heat and fusion stages: Temperatures, Times, Pressures, as well as the Hot plate condition in terms of roughness and

cleanliness Weld dimensions and tolerances Weld inspection procedure and records

The Contractor shall submit draft procedures to the Company for approval at least two weeks prior to the commencement of qualification tests.

A.3 BUTT FUSION WELDING PROCEDURE & BUTT FUSION WELDING OPERATOR QUALIFICATION

For each pipe butt fusion welding procedure to be used for the project a test spool shall be prepared and welded. This shall consist of three pipe sections butt fusion welded together with a flange welded at each end (i.e. 4 circumferential welds in total) of the largest and smallest diameter pipe to be welded. All relevant parameters shall be recorded on a fusion report form. The assembly shall be tested as follows:

Weld dimensions and tolerances of proposed welding procedure. Visual inspection (no visible defects). Ultrasonic and/or radiographic examination when specified by the Company. Acceptance criteria

to be agreed. Pressure test using water at ambient conditions and at a pressure 0.75 times the burst pressure

of the pipe (Table 3). No leakage after 2 hours.

All butt fusion welding operators who successfully complete the above welding procedure qualification shall be considered qualified for butt fusion welds of the same type, material grade and diameter range as represented by the procedure.

All qualified welders shall wear an ID card including a pass photo and stating name, validity (end date of project) diameter range, wall thickness and material grade for which they are qualified. The ID card shall be signed by the Principal.




APPENDIX B - SWELL TEST PROCEDURE

Swell data shall be determined using the following procedure:

- 5 specimens of approximately l*b*h = 5*5*5 mm shall be machined from a sample of the actual PE liner pipe.

- The dimensions of the specimens shall be recorded to the nearest 0.01 mm.- the dry weight of the specimens shall be recorded to the nearest 0.001 gr.- The samples shall be exposed to 500cc of the liquid hydrocarbon phase of the pipeline fluids, for

500 hours or longer (depending on temperature and PE grade) in order to ensure saturation and at the maximum design temperature in a sealed container. The container shall be suitable to safely contain the equilibrium vapor pressure.

- After exposure, the dimensions and weights shall be recorded as above- The linear swell shall be determined as:

(B1)



APPENDIX C - COLLAPSE EQUATION

The collapse pressure of the liner, Pc (bar), is given by (C1);

Where e(swell) = Liner linear swell (%) h = Liner wall thickness (mm)

R = Average radius of the liner (mm) = 0.5*(IDsteel-h)

E = Modulus (in MPa)




APPENDIX D - PE MATERIAL PROPERTIES

The E modulus data in Table D1 have been determined on Philips Marlex HHM TR-480. The ring stiffness test ISO 9969 is used to determine the E-modulus. The following changes were made to the test procedure:

- Specimen length 37.5 mm- Deflections are based on 3% of the outer diameter of the tube whilst calculation of the ring

stiffness is based on the inner diameter

The swell data have been determined on a different grade of PE as described in ARGR.93.106, "Deterioration of HDPE liner material properties in a crude oil environment". For other PE grades the modulus data and the swell data may differ substantially from the data presented. The swell data are for unconstraint PE, excluding constraint effects and excluding stress relaxation effects. In a liner configuration the swell and the resulting compressive stresses in the circumferential direction are expected to be reduced from the values in Table D1. At 60 C in crude oil a value of 2.5% is therefore more realistic and shall be used in the calculations provided that the measured linear swell is not larger than as shown in Table D1 (at the design temperature). If the linear swell is larger than as shown in Table D1 than the Principal shall be consulted. The Contractor shall determine E-modulus and swelling data on the actual PE grades for detailed design.

TABLE D1 - PE MATERIAL PROPERTIES AS A FUNCTION OF TEMPERATURE

Service PE Liner design temperature (ºC)

Linear swell(%)

E Modulus(MPa)

NEN-EN-9969

Poisson’s Ratio

Coefficient of thermal expn.

(m/mK * 10-6

)Air/water 20 870 0.35 120

60 346 0.4070 276 -

Crude 20 2 67860 4 20370 5 162

Notes:

- PE material used:Philips Marlex HHM TR-480 (black HD hexene copolymer PE 3408)Yield: 23 MPa (ASTM 638-M81), Flexural creep modulus 758 MPa (ASTM D 3350)

- The modulus in Table D1 has been determined by ring stiffness tests on 6 and 9 mm thick 6" specimen up to deflection of 3% in 60 seconds, after exposure for 840 hours.

- Relaxation of an additional 120 seconds results in a further 20% reduction of the modulus at 840 hrs.

- Further deflection will also result in a reduction of the modulus.- Exposure: Air, water (50% sea water), Yibal crude- Linear swell is due to the permeation of crude components into the PE



APPENDIX E - PURCHASE ORDER INFORMATION

The following information has to be provided by the Principal in the purchase order:

Process design data Unit ValueTmax, Maximum design temperature CTmin, Minimum design temperature CMinimum ambient temperature CMaximum ambient temperature CMinimum pressure barMaximum design pressure BargPressure fluctuation during normal operation BarPressure fluctuation frequency 1/sGross throughput m3/dayWatercut %For crude oil lines:Bubble point BargGOR at normal conditions m3/m3H2S concentration in gas phase ppmWell stimulation chemicalsWell lift mechanism (ESP, beam pump, etc.)CITHP (closed in tubing head pressure) BargFTHP (flowing tubing head temperature) CCarbon steel line detailsID carbon steel line mm (Inches)Internal condition (corroded/new)Internal condition (max weld penetration) mmDesign life YearsBuried or above groundCoating (presence/colour/type)Liner supply dataPipeline length mSpecified length or coil size mDelivery/shipping instructions




APPENDIX F - PE LINER DESIGN DATA SHEET

The following information has to be provided by the Contractor during the tender:

Installation technique to be used:

Step 1OD mmR = 0.5 * (IDsteel - h) mmStep 2Maximum allowable stress during pulling N/m2Maximum load during pulling NMinimum Wall Thickness (h; h >= 6 mm) mmStep 3 (step 3 to 7 only for crude oil or multiphase service)Service (crude oil or multiphase) ?Maximum design temperature CMaximum linear swell, e(swell) %PE modulus (E) at service conditions (ISO 9969) MPaStep 4Well stabilised crude: Wall thickness (h) for liner stability and a minimum collapse pressure of 3 bar (Appendix C):

mm

Step 5Maximum continuous pressure fluctuation during normal service:

bar

Minimum collapse pressure Pc (>= 3 bar) barStep 6Live crude: Minimum Wall Thickness (h) taking into account continuous pressure fluctuations (step 5) and swell using Appendix C:

mm

Step 7

Minimum Wall Thickness(maximum of step 2, 4, 6)

mm



APPENDIX G - PE MATERIAL PROPERTIES

The following information has to be provided by the Contractor during the tender for:

- PE pipe material- PE flanges- PE lined spools

Property Test Method Minimum requirement

Manufacturer data

PE pipe, flanges or spool ? - -PE Raw Material manufacturer - -PE Grade (unique identification as used by manufacturer)

- -

PE pipe supplier - -Poisson ratio - -Coefficient of thermal expansion

(m/mK * 10-6)

- -

Carbon black content ASTM D3350 2%Density (g/cm3) ASTM D1505 > 0.941Melt index

(g/10min; 190o C, 2160 gr load)

ASTM D1238 < 0.2

Modulus (MPa; 50 mm/min) at 20 C ASTM D638 >750Modulus (MPa) at 20 C ISO 9969 -Modulus (MPa); at 60 C ISO 9969 -Tensile strength (MPa; 50 mm/min) ASTM D638 >18Environmental stress crack resistance (Condition C, 192 hours)

ASTM D1693 Failure less than 20%

Hydrostatic design basis

(MPa at 20o C, 20 years)

ASTM D2837 > 8

Oxygen Induction Temperature

(at 200o C)

ASTM D3895 > 150 minutes

Burst pressure (MPa) ASTM D1599 -




APPENDIX H - INSTALLATION GUIDELINES

H.1 SCOPE

This appendix reviews the typical precautions to be applied during liner installation. Detailed procedures shall be provided by the Installation Contractor.

Two distinct types of liner design are in use: Loose liners are of sufficiently small OD to enable them to be pulled directly through the pipeline and subsequently expanded against the steel pipe inner wall by hydrostatic pressure. Tight fit liners are of similar OD to the pipe ID and are inserted by a combined mechanical squeezing and pulling operation (swaging) to achieve a diameter reduction of around 5%, from which the material spontaneously recovers over a period of hours to achieve a close fit to the host pipe. Experience with liners installed by both techniques is good and there are no demonstrated advantages of one technique above the other in PDO operations.

H.2 Pre-Installation work

H.2.1 Steel pipe

Prior to liner installation the following checks and provisions are required on the steel line:

On existing lines, the condition of the steel pipe shall be assessed to determine that sufficient mechanical strength is retained to meet the design pressure rating for the proposed service, based on hydrotest and/or inspection survey data.

The internal condition and dimensions of all lines must be evaluated to ensure that the liner can be pulled through each segment without significant damage e.g. due to excessive local weld penetration (‘icicles’). These should be checked by gauging pigs/plates and/or by pulling a test sample of liner through every flanged pipe section.

Locations for cutting and flanging of the line and any requirement for separate spooled sections need to be determined. The longest continuous length of liner which can be installed in straight pipe depends on diameter and wall thickness, but is generally reduced in practice by local curvature of the line. Breaks are also required at road crossings, changes in ID and any bends of radius less than 20D, (recommended minimum where possible is 40D).

Flanges welded to the steel line must be of matching bore and with a minimum radius at the inside edge of about 6 mm. Vents shall be welded to the line in accordance with section 3.3 of this specification.

H.2.2 Lining of buried pipelines

For lining existing buried pipelines, bellholes are required at the ends of the line and at any other locations where breaks in the liner need to be made. In addition to the normal safety considerations in excavating, sizing and ensuring stability of the bellholes, the following factors should also be considered:

The working area within the bellhole is required to be of sufficient size to accommodate the pipe fusion machine and operator.

The entry slope shall be sufficiently shallow to enable the liner pipe to bend smoothly from ground level to the pipeline depth without severe abrasion against the steel flange during pull-through. (Provision may also be required for pulling from two directions within a single bellhole)

Provision of sufficient length and width to enable the pipe ends to be offset for flange welding and pulling in of the liner.



H.3 WIRELINE AND PIG TRAIN

The wireline unit should be suitably instrumented with footage and weight indicators, an overload control set to a maximum of 100% of the calculated maximum allowable pulling force and fitted with a speed controllable reel with cable spooling and braking facility.

The Contractor is required to provide suitable pigs and launching equipment to propel the wireline and pig train through the pipeline

A typical pig train should include:

Sizing pig, cleaning pig cup pig segment of liner pipe (for loose liner)

Once the wireline has been passed through the pipeline section, the pig train is pulled through, the pulling force being continuously monitored to determine the location of any constrictions.

For loose fitting liners, the disc plate diameter should generally be about midway between the OD of the liner and the ID of the steel pipe. For tight liners, the disc plate should be of sufficient diameter to verify that internal weld beads do not protrude excessively taking into account the dimensional tolerances of the steel pipe.

Note that the outer diameter of the liner pipe segment should be such that any excess weld penetration which could result in liner puncture during normal operation is detected. For loose liners this could imply that a larger diameter liner pipe may be necessary for test purposes than during operation.

The liner test segment attached to the pig train should emerge without serious damage. Scuffing of the liner surface is permissible but sharp longitudinal scars or other penetration damage exceeding 0.5 mm or 5% of the wall thickness, which ever is larger, is unacceptable and would require rectification by further pigging using a breaker pig or by other means prior to continuing with liner installation. After rectification another liner test segment shall be pulled through.

H.4 LINER INSTALLATION

H.4.1 PRE-FABRICATION

Each segment of liner is first fabricated from the supplied pipe lengths by butt fusion welding (ASTM 2657) to form a continuous length. Welding procedures shall be prepared and qualified in accordance with Appendix A of this specification. The following are applicable to the welding process and its control:

Welding procedures shall be in accordance with the recommendations of the liner supplier. The Contractor shall be responsible for providing the fusion machine, ancillary equipment and

any necessary environmental protection. Detailed production and inspection records shall be maintained, including, for each joint, location,

pipe identification, batch number, operator etc. Trimming with an approved tool of the external bead, and, if required by the Principal, the

internal bead.

The following testing and inspection of field joints shall be carried out:

Visual inspection of the welds and the full circumference of trimmed beads for evidence of lack of fusion.

Production testing to confirm the correct machine parameters are maintained. A test sample (strip) of butt welded pipe should be subjected to a 180º reverse bend test without failure. The




test should be conducted daily, for every flanged section, whichever is more frequent, and additionally whenever machine settings are altered.

Low pressure air test of completed liner prior to installation (maximum pressure approximately 0.3 MPa). All fusion joints should be checked for leakage with a soap solution, witnessed by a Company representative.

H.4.2 LINER INSERTION

The liner is pulled through the pipe section at a controlled rate using an adequately designed pulling head. The following points are to be noted:

Pulling shall be at a controlled rate consistent with safe working conditions. Pulling force shall be monitored to ensure that 50-70% of the PE pipe yield stress (at the

maximum ambient temperature) is not exceeded during the operation. Readings to be recorded by the Contractor.

Precautions shall be taken to ensure that no debris is introduced into the line on the external or internal surface of the liner.

If the use of a friction reducing agent is proposed by the Contractor the type and application method shall be approved by the Company.

H.4.3 FLANGING OF LINER ENDS

When the liner has been pulled in, flange adapters are fusion welded to each end. The method shall be detailed by the Contractor but will generally involve the following steps:

Welding a flange adapter to the liner segment trailing end and pulling in to the steel flange. Clamping and stretching the liner from the leading end, sufficient to trim to required length and

butt the second flange adapter. (Normally a minimum 100 m segment length is required for this technique to accommodate the necessary elastic strain).

Releasing the clamp to allow the liner to contract on to the steel flange face. Fitting metal retaining rings around the liner flanges. These are designed to a controlled

thickness to limit compression of the PE flanges to a pre-determined value when bolting adjacent segments and to prevent spreading of the PE material under load.

H.4.4 EXPANSION AND HYDROSTATIC TESTING

All installed liners shall be subjected to a leak test per segment and a hydrostatic test of the complete line. For loose installed liners a separate expansion operation may be required. Detailed procedures shall be submitted by the Contractor for Company approval.

H.4.5 TESTING AFTER COMMISSIONING

All vents should be opened between two to four weeks after commissioning to check the integrity of the liner.



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ERD-43-15 (2)

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Transcript of ERD-43-15 (2)