31403032 External Fusion-bonded Epoxy Powder Coating for Line Pipe

DEP SPECIFICATION

EXTERNAL FUSION-BONDED EPOXY POWDER COATING FOR LINE PIPE (AMENDMENTS/SUPPLEMENTS TO ISO 21809-2:2007)

DEP 31.40.30.32-Gen. February 2011

DESIGN AND ENGINEERING PRACTICE

© 2011 Shell Group of companies All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, published or transmitted, in any form or by any means, without the prior written permission of the copyright owner or Shell Global Solutions International BV.

DEP 31.40.30.32-Gen. February 2011 Page 2

PREFACE DEP (Design and Engineering Practice) publications reflect the views, at the time of publication, of Shell Global Solutions International B.V. (Shell GSI) and, in some cases, of other Shell Companies. These views are based on the experience acquired during involvement with the design, construction, operation and maintenance of processing units and facilities. Where deemed appropriate DEPs are based on, or reference international, regional, national and industry standards. The objective is to set the recommended standard for good design and engineering practice to be applied by Shell companies in oil and gas production, oil refining, gas handling, gasification, chemical processing, or any other such facility, and thereby to help achieve maximum technical and economic benefit from standardization. The information set forth in these publications is provided to Shell companies for their consideration and decision to implement. This is of particular importance where DEPs may not cover every requirement or diversity of condition at each locality. The system of DEPs is expected to be sufficiently flexible to allow individual Operating Units to adapt the information set forth in DEPs to their own environment and requirements. When Contractors or Manufacturers/Suppliers use DEPs, they shall be solely responsible for such use, including the quality of their work and the attainment of the required design and engineering standards. In particular, for those requirements not specifically covered, the Principal will typically expect them to follow those design and engineering practices that will achieve at least the same level of integrity as reflected in the DEPs. If in doubt, the Contractor or Manufacturer/Supplier shall, without detracting from his own responsibility, consult the Principal. The right to obtain and to use DEPs is restricted, and is granted by Shell GSI (and in some cases by other Shell Companies) under a Service Agreement or a License Agreement. This right is granted primarily to Shell companies and other companies receiving technical advice and services from Shell GSI or another Shell Company. Consequently, three categories of users of DEPs can be distinguished: 1)

Operating Units having a Service Agreement with Shell GSI or another Shell Company. The use of DEPs by these Operating Units is subject in all respects to the terms and conditions of the relevant Service Agreement.

2)

Other parties who are authorised to use DEPs subject to appropriate contractual arrangements (whether as part of a Service Agreement or otherwise).

3)

Contractors/subcontractors and Manufacturers/Suppliers under a contract with users referred to under 1) or 2) which requires that tenders for projects, materials supplied or - generally - work performed on behalf of the said users comply with the relevant standards.

Subject to any particular terms and conditions as may be set forth in specific agreements with users, Shell GSI disclaims any liability of whatsoever nature for any damage (including injury or death) suffered by any company or person whomsoever as a result of or in connection with the use, application or implementation of any DEP, combination of DEPs or any part thereof, even if it is wholly or partly caused by negligence on the part of Shell GSI or other Shell Company. The benefit of this disclaimer shall inure in all respects to Shell GSI and/or any Shell Company, or companies affiliated to these companies, that may issue DEPs or advise or require the use of DEPs. Without prejudice to any specific terms in respect of confidentiality under relevant contractual arrangements, DEPs shall not, without the prior written consent of Shell GSI, be disclosed by users to any company or person whomsoever and the DEPs shall be used exclusively for the purpose for which they have been provided to the user. They shall be returned after use, including any copies which shall only be made by users with the express prior written consent of Shell GSI. The copyright of DEPs vests in Shell Group of companies. Users shall arrange for DEPs to be held in safe custody and Shell GSI may at any time require information satisfactory to them in order to ascertain how users implement this requirement. All administrative queries should be directed to the DEP Administrator in Shell GSI.

DEP 31.40.30.32-Gen. February 2011 Page 3 TABLE OF CONTENTS PART I 1. 1.1 1.2 1.3 1.4 1.5 1.6 1.7 2. 2.1 2.2 2.3 2.4 2.5 PART II 1 3 4 6 6.3 7.2 8 8.1 8.2 8.3 9.1 9.2 9.3 9.4 10. 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8

INTRODUCTION AND GENERAL REQUIREMENTS...............................................5 INTRODUCTION ........................................................................................................5 SCOPE........................................................................................................................5 DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS .........5 DEFINITIONS .............................................................................................................5 ABBREVIATIONS .......................................................................................................6 CROSS-REFERENCES .............................................................................................6 CHANGES FROM THE PREVIOUS EDITION ...........................................................6 COMMENTS ON THIS DEP .......................................................................................6 GENERAL REQUIREMENTS.....................................................................................7 GENERAL ...................................................................................................................7 DOCUMENT HIERARCHY .........................................................................................7 SAFETY ......................................................................................................................7 COMPANY ACCESS ..................................................................................................7 PRE-JOB MEETING ...................................................................................................8

AMENDMENTS/SUPPLEMENTS TO ISO 21809-2 ..................................................9 SCOPE........................................................................................................................9 TERMS AND DEFINITIONS .......................................................................................9 SYMBOLS AND ABBREVIATED TERMS ..................................................................9 INFORMATION SUPPLIED BY THE PURCHASER ..................................................9 INFORMATION TO BE SUBMITTED BY THE COATING CONTRACTOR.............10 EPOXY POWDER ....................................................................................................10 COATING QUALIFICATION .....................................................................................10 COATING SYSTEM QUALIFICATION .....................................................................11 APPLICATOR QUALIFICATION...............................................................................15 PREPARATION OF LABORATORY-COATED TEST SPECIMENS........................15 PRODUCTION APPLICATION PRACTICES AND EQUIPMENT ............................16 SURFACE PREPARATION ......................................................................................16 APPLICATION AND CURING TEMPERATURES....................................................17 COATING THICKNESS ............................................................................................17 INSPECTION AND TESTING...................................................................................17 GENERAL .................................................................................................................18 IDENTIFICATION OF EPOXY POWDER RESIN.....................................................18 AMBIENT CONDITIONS ..........................................................................................18 INSPECTION OF UNCOATED PIPES BEFORE BLASTING ..................................18 INSPECTION AFTER BLASTING ............................................................................18 APPLICATION TEMPERATURES ...........................................................................19 APPEARANCE, THICKNESS AND HOLIDAYS.......................................................19 DEGREE OF CURE, MICROSCOPIC EXAMAMINATION, ADHESION AND IMPACT TESTING....................................................................................................20 10.9 FLEXIBILITY TEST, HOT WATER TEST AND CATHODIC DISBONDING TEST .........................................................................................................................20 10.10 ACCEPTANCE OF FAILED PIPES ..........................................................................20 10.11 TRACEABILITY OF PIPES AND COATING.............................................................20 11. REPAIR OF COATED PIPE .....................................................................................20 11.2 REPAIR OF HOLIDAYS ...........................................................................................20 13. HANDLING AND COATING IN THE STORAGE AREA...........................................21 13.2 STORAGE.................................................................................................................21 13.3 TRANSPORT OF COATED PIPE ............................................................................21 14. TEST REPORTS AND CERTIFICATE OF COMPLIANCE ......................................22 ANNEX A.4 DRY ADHESION TEST ............................................................................................23 ANNEX A.9 CATHODIC DISBONDMENT OF THE COATING....................................................23 ANNEX A.11 . .................................................................................................................................23 ANNEX A.15 . .................................................................................................................................24 ANNEX A.16 COATING THICKNESS ............................................................................................24 ANNEX A.17 HOLIDAY DETECTION ............................................................................................25 ANNEX A.18 PHOSPHORIC ACID TREATMENT .........................................................................25

DEP 31.40.30.32-Gen. February 2011 Page 4 ANNEX A.19 CONDUCTIVITY MONITORING OF BLASTING MATERIAL EXTRACTS ..............26 PART III

REFERENCES .........................................................................................................27

DEP 31.40.30.32-Gen. February 2011 Page 5 PART I INTRODUCTION AND GENERAL REQUIREMENTS

1.

INTRODUCTION

1.1

SCOPE This DEP specifies requirements and gives recommendations for factory-applied external single and dual layer fusion-bonded epoxy (FBE) powder coating for corrosion protection of steel pipes, bends and fittings used for buried or submerged pipelines. It specifies the requirements for coating materials, coating application, inspection and testing, repair, handling and storage. This DEP also gives procedures for qualification of coating materials and coating applicators. Part II of this DEP amends, supplements and deletes various clauses of ISO/DIS 21809-2:2007. Part II follows the clause numbering ISO/DIS 21809-2:2007 for easy reference. This DEP is a revision of the DEP of the same number and title dated April 2003; see (Part I, 1.6) regarding the changes.

1.2

DISTRIBUTION, INTENDED USE AND REGULATORY CONSIDERATIONS Unless otherwise authorised by Shell GSI, the distribution of this DEP is confined to Shell companies and, where necessary, to Contractors and Manufacturers/Suppliers nominated by them. Any authorised access to DEPs does not for that reason constitute an authorization to any documents, data or information to which the DEPs may refer. This DEP is intended for use in oil refineries, chemical plants, gas plants, exploration and production facilities and supply/distribution installations. This DEP may also be applied in other similar facilities. When DEPs are applied, a Management of Change (MOC) process should be implemented; this is of particular importance when existing facilities are to be modified. If national and/or local regulations exist in which some of the requirements may be more stringent than in this DEP, the Contractor shall determine by careful scrutiny which of the requirements are the more stringent and which combination of requirements will be acceptable with regard to the safety, environmental, economic and legal aspects. In all cases the Contractor shall inform the Principal of any deviation from the requirements of this DEP which is considered to be necessary in order to comply with national and/or local regulations. The Principal may then negotiate with the Authorities concerned, the objective being to obtain agreement to follow this DEP as closely as possible.

1.3

DEFINITIONS

1.3.1

General definitions The Contractor is the party that carries out all or part of the design, engineering, procurement, installation, and commissioning or management of a project or operation of a facility. The Principal may sometimes undertake all or part of the duties of the Contractor. The Manufacturer/Supplier is the party that manufactures or supplies equipment and services to perform the duties specified by the Contractor. The Principal is the party that initiates the project and ultimately pays for its design and construction. The Principal will generally specify the technical requirements. The Principal may also include an agent or consultant authorised to act for and on behalf of the Principal. The word shall indicates a requirement. The word should indicates a recommendation.

DEP 31.40.30.32-Gen. February 2011 Page 6 1.3.2

Specific definitions The Applicator - the party that applies the fusion-bonded epoxy powder coating system in the coating plant. Batch - the amount of materials produced within one uninterrupted production run of maximum 10 h under constant production conditions. Chemical pre-treatment - the treatment of the blast-cleaned pipe surface with a chemical solution (e.g. phosphate) before application of the coating layer to improve the adhesion of the coating to the substrate. Coating contractor - the party that is ultimately responsible for the coating operation, which may include supply of coating materials, application of the coating and transport of uncoated and coated line pipe as specified in the relevant contract. The Coating Contractor may be the Applicator, the Coating Manufacturer, the Line Pipe Manufacturer or the Pipeline Construction Contractor. Holiday - a defect penetrating through the coating to the steel pipe surface, whereby its dimensions is detectable by means of the specified procedures. Inspector - the party appointed by the Principal to witness the Applicator's quality control of coating materials and the coating process. Qualification trial – process of application of the total coating system and subsequently inspection/testing of its properties to confirm that the coating system and coating applicator are adequate to produce the coating of specified properties. The qualification trial shall be carried out prior to any start of production coating. Shift – duration of a normal work cycle of which the beginning and end coincide with a change in personnel. In the context of the quality control procedures of this DEP, the maximum duration of a shift is 10 hours. Unit of production – unless otherwise specified, a set of pipes coated in one production run on the same coating line, having the same nominal diameter and wall thickness and coated with the same coating products. Breaks in production caused by equipment or plant breakdown, factory shutdown, or any break in production exceeding three days shall be the end of a production run. Subsequent start-up constitutes a new unit of production.

1.4

1.5

ABBREVIATIONS AFC

Approved For Construction

ITP

Inspection and Test Plan

MP

Manufacturing Plan

QP

Quality Plan

CROSS-REFERENCES Where cross-references to other parts of this DEP are made, the referenced section is shown in brackets. Other documents referenced in this DEP are listed in (Part III).

1.6

CHANGES FROM THE PREVIOUS EDITION This DEP is a revision of the DEP of the same number dated April 2003. This revision is written in the form of amendments/supplements to ISO/DIS 21809-2:2007 and it is therefore impractical to summarise the changes here.

1.7

COMMENTS ON THIS DEP Comments on this DEP may be sent to the Administrator at [email protected], using the DEP Feedback Form. The DEP Feedback Form can be found on the main page of “DEPs on the Web”, available through the Global Technical Standards web portal http://sww.shell.com/standards and on the main page of the DEPs DVD-ROM.

DEP 31.40.30.32-Gen. February 2011 Page 7 2.

GENERAL REQUIREMENTS

2.1

GENERAL Part II of this DEP amends, supplements and deletes various clauses/paragraphs of ISO/DIS 21809-2:2007. Wherever reference is made to ISO/DIS 21809-2, it shall be understood to mean ISO/DIS 21809-2:2007 as amended/supplemented by this DEP. For ease of reference, the clause numbering of ISO/DIS 21809-2 has been used throughout Part II of this DEP. Clauses of ISO/DIS 21809-2 that are not mentioned in this DEP shall remain applicable as written.

2.2

DOCUMENT HIERARCHY In the event of conflicts between contract documents, AFC drawings, specifications and other referenced standards, the following document hierarchy shall apply:

2.3

•

Contract or agreement (including any approved exceptions)

•

AFC drawings – latest revisions

•

Principal’s specifications (including project specific information)

•

Industry Standards (e.g. ISO, NACE)

SAFETY Application of coatings can include the use of hazardous materials, operations and equipment. This DEP does not purport to address all the potential safety concerns associated with their use. It is the responsibility of the Applicator to establish appropriate safety and health requirements and determine any regulatory requirements or limitations prior to use Health, Safety and Environment concerns shall be identified and included in the detailed coating procedure and pre-job discussions. All surface preparation and coating application systems shall undergo a complete safety inspection and checkout prior to use. Adequate exhaust/ventilation equipment shall be used, as required, for removal of any air contaminated products to achieve acceptable air quality standards and to protect personnel. The safe practices recommended in industry standards shall be followed. Waste material shall be handled and disposed of properly. Protective equipment requirements in the Manufacturer’s Material Safety Data Sheet(s) shall be followed. Coating work pieces shall be electrically grounded (earthed) as required to eliminate static charges associated with surface preparation and coating operations.

2.4

COMPANY ACCESS The Principal’s representative, including independent inspectors or consultants as may be engaged by the Principal, shall be permitted access to the coating application site at any time to conduct performance analyses, including quality control tests of the materials being used. The Principal’s representative has the right to reject any or all work or equipment that in his/her opinion does not conform to these requirements. Any work that in the opinion of the Principal’s representative does not comply with these requirements shall be rectified at the Contractor’s expense. The Principal’s representative has the right to request quality control tests at any time in addition to those completed at pre-determined intervals.

DEP 31.40.30.32-Gen. February 2011 Page 8 2.5

PRE-JOB MEETING The Applicator shall schedule a pre-job meeting to ensure that job requirements are fully understood. The personnel present at the meeting shall include, but not be limited to, the Principal’s representative and the Applicator’s representatives for coating supervision, quality control and safety. If required a technical representative of the Manufacturer shall be present. Roles and responsibilities shall be clarified at the pre-job meeting, such as when the Principal deals with the Applicator, who are the focal points and how administration procedures are executed. It shall be confirmed that all parties have the latest version of the Contract, technical specifications, AFC drawings and ITP.

DEP 31.40.30.32-Gen. February 2011 Page 9 PART II AMENDMENTS/SUPPLEMENTS TO ISO 21809-2 1

SCOPE Delete the second paragraph. Add the following: Suitability of a coating system for a particular temperature class shall be demonstrated by performing the qualification tests at the relevant test temperature given in this DEP. For a specific project, additional testing should be performed at the temperature specified in the project documentation. The coating system described in this DEP shall be made with the use of FBE powder as the main coating material, by means of suitable surface preparation and application techniques to obtain the coating properties required for the intended installation and operating conditions.

3

TERMS AND DEFINITIONS Definitions in (I-1.3) of this DEP shall also apply.

4

SYMBOLS AND ABBREVIATED TERMS Abbreviations in (I-1.4) of this DEP shall also apply.

6

INFORMATION SUPPLIED BY THE PURCHASER

6.1

GENERAL INFORMATION Delete and replace with the following: For a specific project, the Principal shall submit all technical information to the Coating Contractor regarding the project, in particular the installation and operating conditions. This information shall include as a minimum: -

project name; type of coating required; maximum/minimum design and operating temperature of the pipeline; description of steel pipe; applicable line pipe specification; geographical area (land/sub-sea); expected field joint coating with application guidelines; cutback configuration and finish; expected ambient temperatures during installation; installation method; soil and backfill conditions for land pipelines; sea bed trenching, laying and burial conditions for sub-sea pipelines; subsequent coatings to be applied (weight coating, insulation); requirement for anti-slip treatment; requirements for temporary protection of pipe ends; types of cathodic protection.

The Principal shall indicate whether a specific brand of coating shall be used or whether the Coating Contractor shall select the coating.

DEP 31.40.30.32-Gen. February 2011 Page 10 Add the following: 6.3

INFORMATION TO BE SUBMITTED BY THE COATING CONTRACTOR The Contractor shall submit information to the Principal on the coating system to be used. This information shall include as a minimum: -

system identification; Manufacturer's data; system qualification information; coating application procedures; name(s) of the proposed Coating Applicator(s); Applicator's qualification information; Quality Plan consisting of Manufacturing Plan (MP) and Inspection and Test Plan (ITP).

The Contractor shall confirm that the coating system is suitable for use under the specified conditions. 7.2

EPOXY POWDER

7.2.1

General a) Add the following: Material that is not traceable to satisfactory test certificates shall not be used. d) Sample retention Three samples of 50 g each shall be taken from each batch of powder. These samples shall be marked and stored by the Applicator under conditions such that the powder does not deteriorate. The Principal may request tests on these samples up to six months after delivery of the last coated pipe of the order, or later if agreed between Applicator and Principal.

7.2.2

Properties Amendments to Table 1: Total volatile/moisture content by mass: < 0.5 % Thermal characteristics – The glass transition temperature (Tg2) shall be at least 5 °C above the maximum pipeline design temperature.

8

COATING QUALIFICATION Add the following: This DEP may be used for general qualification purposes or for specific projects. General coating qualification is performed for the purpose of an overall qualification of the coating system and Applicator, but not necessarily related to a specific project. Coating systems shall be technically qualified to the satisfaction of the Principal and shall be applied by Applicators acceptable to the Principal. NOTE:

For this purpose Shell companies may use the list of Technically Accepted Manufacturers and Products maintained by Shell Projects and Technology.

The general qualification is given independently of line pipe diameter and wall thickness. When required for specific projects, additional testing should be performed on different line pipe diameters and wall thicknesses. Because there are a large variety of different grades of epoxy powder, no maximum temperature limits are indicated for the coating systems.

DEP 31.40.30.32-Gen. February 2011 Page 11 To facilitate the selection of suitable coating systems, the coating system shall be qualified at its maximum allowable temperature. For general coating qualification, the Coating Manufacturer/Applicator shall specify the maximum allowable temperature. The maximum allowable temperature shall include the temperature during transport, storage, installation (i.e. installation of field joint coating systems), design and operation of the coated pipeline. Replace clauses 8.1 and 8.2 with: 8.1

COATING SYSTEM QUALIFICATION Before a coating system can be specified for an application, the Contractor or the coating Manufacturer shall request qualification trials of the coating system. The qualification trials shall be carried out according to the following procedures. The Contractor or the coating Manufacturer shall submit all data specified in (7.2). The coating system shall be applied at the Applicator’s coating line (qualification shall be carried out separately for each coating line) by the Applicator on at least five pipes of the specified pipe material and the coating system shall be subjected to the tests as specified in Table 2. The tests shall be carried out by an independent test laboratory or, if approved by the Principal, by the Applicator. The Principal shall witness the application and the tests. The number of pipes to be tested and the test procedures are given in Table 2. When this DEP is used for the coating of bends and/or fittings, the Applicator shall perform the qualification testing on one straight length of pipe. The required qualification tests for bends and fittings are the same as for pipes as given in Table 2. If agreed by the Principal, previous qualification data can be used provided that the above-mentioned tests have been carried out using the same coating system and the same coating process as specified in the contract. With the approval of the Principal, tests carried out in accordance with other coating standards may be used insofar as their procedures are the same as or more stringent than the procedures in this DEP. Such information shall include full reports on test procedures and results and be signed by the laboratory representatives and certification body. Include Table 2 Table 2

Minimum requirements during Qualification and Coating Production Property

Paragraph

Test frequency Qualification

Test frequency Production

10.3

once

once every 2 hours

Surface condition before blasting

10.4

5 pipes

each pipe

Cleanliness of blast cleaned surface

9.2.2

5 pipes

9.2.3

5 pipes

first 5 pipes and one of 20 pipes

9.2.2

5 pipes


9.2.4

5 pipes


Ambient conditions

Cleanliness of blast cleaned surface (dust level) Surface profile Surface cleanliness Chlorides

each pipe


Property

Paragraph

Test frequency Qualification

10.5

Once

10.6

Continuous

Continuous

8.1.1.1

5 pipes

each pipe

Coating thickness

8.1.1.4

5 pipes

each pipe

Holiday detection

8.1.1.5

5 pipes

each pipe

Blast cleaning materials and process Coating application temperature Appearance

Adhesion

8.1.1.6

5 pipes

Test frequency Production as per(10.5)

one of every 50 pipes (minimum one pipe per shift)

Impact

8.1.1.7

5 pipes


Degree of cure of FBE

8.1.1.2

5 pipes


Microscopic examination

8.1.1.3

5 pipes


Hot water resistance

8.1.1.9

2 pipes


Cathodic disbonding

8.1.1.10

2 pipes


Flexibility

8.1.1.8

2 pipes


8.1.1

Finished coating system requirements

8.1.1.1

Visual appearance The coating shall be free from blisters, visual holidays, scratches or any other irregularities and shall have a uniform colour and gloss.

8.1.1.2

Degree of cure The degree of cure shall be determined by differential scanning calorimetric in accordance with (A.8). The ∆Tg value shall be between -2 °C and +3 °C. The glass transition temperature (Tg4) shall be at least 5 °C above the maximum pipeline design temperature.

8.1.1.3

Microscopic examination A sample of the applied coating shall be examined for: a) porosity; and b) surface contamination in accordance with the procedure in (A.10) and (A.11).

DEP 31.40.30.32-Gen. February 2011 Page 13 The maximum degree of porosity shall be 2 on the scale given in Figure A.10, for both the cross-section of the coating and at the interface of the coating. The coating side at the coating-steel interface shall be free of visual contamination. The maximum allowable contamination is 10 %. The visual surface contamination should be identified as the percentage of steel dust versus oxide or other particles. The addition of a saturated copper sulphate solution to the back of the chip will cause steel dust to be plated with copper to make it easily identifiable. This definition of contaminant types should help the Applicator adjust the surface preparation procedures to minimize the amount of surface contamination. (Modified NACE RP 0394-2002 Appendix K). 8.1.1.4

Coating thickness The thickness of the cured single layer FBE coating shall be 475 µm ± 75 µm, unless otherwise specified by the Principal. The thickness of the cured double layer FBE coating shall be 700 µm ± 100 µm, unless otherwise specified by the Principal. The base coat and top coat shall each be 350 µm ± 50 µm For pipes that are to be coated later with concrete weight coating using an impingement technique without an intermediate barrier coating for mechanical protection, the thickness of the cured FBE coating shall be 725 ± 75 µm. The thickness of the cured FBE coating applied on bends and fittings shall be not less than 400 µm and shall be not more than 1000 µm. The coating thickness shall be measured in accordance with (A.16).

8.1.1.5

Holidays The coating system shall be free from holidays that are indicated when tested in accordance with (A.17).

8.1.1.6

Adhesion When tested in accordance with (A.4), the adhesion of the coating system shall be such that any attempt to remove the coating shall result in a cohesive break in the coating material and not in an adhesive failure of the coating/substrate interface. An adhesive breakaway from the point of intersection of more than 2 mm, or a brittle breakaway of flakes of more than 2 mm constitutes a failure. Absence of peeling, or a cohesive break less than 2 mm long entirely within the coating, constitutes a pass. Cohesive failure caused by voids in the coating leaving a honeycomb structure on the steel surface also constitutes a failure. For qualification testing, the adhesion of the coating system shall also be tested by the dolly pull off method in accordance with (A.4). The pull-off adhesion strength shall be more than 10 N/mm2 and the failure mode shall be cohesive for more than 75 % of surface area.

8.1.1.7

Impact resistance The impact resistance of the coating system shall be tested at ambient temperature in accordance with the procedure in (A.13). For the single layer FBE coating system the impact resistance shall be more than 1.8 J and for the dual layer FBE coating system the impact resistance shall be more than 3.6 J. For qualification testing, the impact resistance of the coating system shall also be tested at -30 °C. The impact resistance shall be more than 1.5 J.

8.1.1.8

Flexibility The flexibility of the coating shall be such that holidays do not appear when it is tested in accordance with the procedure in (A.12).

DEP 31.40.30.32-Gen. February 2011 Page 14 8.1.1.9

Hot water resistance Hot water resistance shall be tested in accordance with (A.15) at a test temperature related to the operating temperature as specified in Table 3. The duration of the test for coating qualification shall be 28 days. After the exposure, the coating shall show no significant evidence (less than 10 % of the test area) of blistering or disbonding and shall show no failure of adhesion when tested in accordance with (A.4). For qualification testing, the adhesion of the coating system shall also be tested by the dolly pull off method, see (A.4). The pull off adhesion strength shall be more than 7 N/mm2 and the major failure mode (> 50 % of surface area) shall be cohesive. For quality control purposes (10.9), the duration of the hot water resistance test shall be 48 hours and the coating shall show no significant evidence (less than 5 % of the test area) of blistering or disbonding, and shall show no failure of adhesion when tested in accordance with (A.4). Table 3

Hot water test temperature

Operating temperature, °C

Test temperature, °C

< 20

20 ± 2

20 to 60

60 ± 2

60 to 80

80 ± 2

> 80

Operating temperature ± 2 (maximum temperature is 95 ± 2)

8.1.1.10 Cathodic disbonding resistance Cathodic disbonding shall be tested in accordance with (A.9) at a test temperature related to the operating temperature as specified in Table 4. The duration of the test for coating qualification shall be 28 days. After the test, the maximum radius of disbonding shall be less than the value given in column 3 (28 days) of Table 4. For quality control purposes (10.9), the duration of the test shall be 48 hours and the radius of disbonding shall be less than the value given in column 4 (48 hours) of Table 4. Table 4 Cathodic disbonding resistance Operating temperature, °C

Test temperature, °C

Maximum disbonding radius, mm 28 days Qualification

48 hours, Quality Control

< 20

20 ± 2

5

3

20 to 60

60 ± 2

10

5

60 to 80

80 ± 2

10

5

> 80

Operating temperature ± 2 (maximum temperature is 95 ± 2)

10

5


APPLICATOR QUALIFICATION

8.2.1

General Before production application of a coating system may commence, the Applicator shall be qualified to apply the coating system. The qualification shall be carried out according to the following procedures:

8.2.2

Coating process and applicator selection The Coating Contractor shall submit to the Principal, information on the required coating process and recommended Applicators. The information shall include: 1. 2. 3. 4. 5. 6.

8.2.3

Description of the coating process; Pipe cleaning procedure and pipe surface preparation (cleanliness, profile, chemical treatment, etc.); Pipe heating and temperature control; Cure times and quenching details; Recommended Applicators; Coating repair procedures.

Coating plant To demonstrate that the available equipment is capable of applying the specified coating according to the required standards, each recommended Applicator shall submit details of the coating plant, including: 1. 2. 3. 4. 5.

8.2.4

Layout diagram of the coating plant and pipe routing scheme; General description of the equipment available to carry out the coating process; Details of process control and inspection equipment, required for the coating process such as temperature control, thickness control, holiday testers, laboratory equipment; Details of the pipe handling and transport equipment and procedures; Applicator's quality control procedures.

Qualification After approval of the process and plant details (8.2.2 and 8.2.3) and before production starts, the Applicator shall submit evidence that he has successfully applied the coating system (or one similar) before on pipes like those to be coated under the contract and that the product should comply with the requirements of this DEP for the tests indicated in Table 2. When this DEP is used for the coating of bends and/or fittings, the Applicator shall perform the pre-production testing on one straight length of pipe. The required qualification tests for bends and fittings are the same as for piping given in Table 2. When chemical pre-treatment is to be used for the coating system, the Principal may request that part of the pre-production testing shall be carried out on chemically treated pipe and the remainder on untreated pipe, in order to ensure that the FBE powder is of a quality essential to long-term coating performance. This may be done by partly treating each length of pipe. In this case the coating on both the treated and untreated surfaces shall pass the tests.

8.3

PREPARATION OF LABORATORY-COATED TEST SPECIMENS Amend the first sentence in the third paragraph: The thickness of coating on the completed test specimen shall be 475 ± 75 µm for single layer FBE coating and 700 ± 100 µm for dual layer FBE coating.


PRODUCTION APPLICATION PRACTICES AND EQUIPMENT Amend the sentence: The coating system and Applicator shall have been previously qualified in accordance with section 8.

9.2

SURFACE PREPARATION

9.2.1

Initial preparation Add the following: Before blasting begins, the chloride contamination may be evaluated according to (9.2.4). A minimum of two sites shall be selected at the most heavily rusted areas on the pipe surface, including apparent drip lines and contact lines. The initial chloride level should be used to determine the phosphoric acid surface treatment parameters, if required.

9.2.2

Abrasive blast cleaning Add the following: During blast-cleaning the pipe surface temperature shall be simultaneously higher than 5 °C and more than 3 °C above the ambient dew point. The relative humidity shall not exceed 85 %. Line speed and blasting parameters shall not cause any over blasting of the pipe surface and result in microscopic steel laminations that may disband from the pipe surface. If required by the Principal, microscopic examination shall be carried out. Stainless steel or non-ferrous abrasives shall be used for blast cleaning of stainless steel pipes. Immediately after blast-cleaning, all remaining weld spatter and irregularities shall be removed from the pipe surface by chiselling and/or grinding. Any treated surface with an area larger than 25 cm2 shall be re-blasted to the cleanliness and roughness as specified above. No repairs to the pipe shall be made without a procedure agreed by the Principal. After any grinding or mechanical repairs, the remaining wall thickness shall be checked and compared with the minimum requirements of the line pipe specification. Pipes not meeting the minimum wall thickness shall be rejected. Before coating, the pipe surface shall be cleaned of all dust and foreign matter by means of clean dry compressed air or vacuum cleaning. The compressed air shall be free of any trace of oil.

9.2.3

Surface cleanliness Amend this section as follows:

9.2.3

Dust level The dust level on the blast-cleaned surface shall be of Class 1 in accordance with ISO 8502-3.

9.2.4

Surface pre-treatment Delete the last two paragraphs Add the following: The phosphoric acid wash may be used as an optional surface treatment if the initial chloride level is more than 50 mg/m2 or when specified by the Principal or coating Applicator. This treatment shall be conducted in accordance with (A.18) and should be executed after all surface preparation operations and just prior to heating for coating application.

DEP 31.40.30.32-Gen. February 2011 Page 17 Acid concentration, pipe temperature, dwell time, rinse water conductivity and pipe surface pH shall be monitored twice per shift. Testing for the presence of chlorides shall be undertaken in accordance with ISO 8502-6 or ISO 8502-9 or any other method approved by the Principal. The maximum residual chloride level on the blast cleaned surface shall be 20 mg/m2 9.3

APPLICATION AND CURING TEMPERATURES Replace this section with the following:

9.3

COATING APPLICATION Blast-cleaned pipes shall be coated within 4 hours. Pipes delayed beyond this period, or pipes showing any visible rust stains, shall be blast cleaned again. When due to unforeseen circumstances, the relative humidity is more than 85 %, the blast cleaned pipes shall be coated within one hour. The application of the coating shall be in accordance with the coating Manufacturer’s application procedures. During the coating process, the preheating temperatures shall comply with the requirements given in the application procedures. The maximum pipe temperature shall be 280 °C. Heating equipment shall be controlled to maintain uniform temperatures throughout the coating process. The use of recycled powder from the same batch shall be permitted but it shall not exceed 20 % of the total powder mix at any time. Recovery shall be automatic and continuous. This powder shall be processed through magnetic separators and sieves and then uniformly mixed with fresh powder. When recycled powder is used, the moisture content of the powder shall be checked at least once per day and shall be in accordance with (A.5). The sequence of use of the batches of epoxy powder shall be in the order in which they were manufactured. Different brands of powders shall not be mixed. During coating, the bevelled ends of the pipes and the pipe bore shall be protected against mechanical damage and from contamination with coating material. Each pipe end shall be left uncoated over a length as specified by the Principal. Uncoated pipe ends shall receive a temporary protective coating for transit, unless otherwise specified by Principal. If the Manufacturer requires the post-curing of the coating on the bends and fittings, this shall be done in an oven for a maximum time of 15 min, at a maximum temperature of 250 °C. Following such a curing process, the bend or fitting may be allowed to cool to ambient temperatures in air as an alternative to water quenching.

9.4

COATING THICKNESS Amend the paragraph as follows: The thickness of the cured FBE coating shall be 475 µm ± 75 µm, unless otherwise specified by the Principal. For pipes that are to be coated later with concrete weight coating using an impingement technique without an intermediate barrier coating for mechanical protection, the thickness of the cured FBE coating shall be 725 ± 75 µm. The thickness of the cured FBE coating applied on bends and fittings shall be not less than 400 µm and shall be not more than 1000 µm. The coating thickness shall be measured in accordance with (A.18).

10.

INSPECTION AND TESTING Delete this section and add the following:

DEP 31.40.30.32-Gen. February 2011 Page 18 10.

QUALITY CONTROL

10.1

GENERAL During production application of the coating, the Applicator shall carry out the quality control activities needed to ensure that the coating is applied and stored in accordance with the approved coating application procedures and that the final product complies with the requirements of this DEP. A Quality Plan (QP) consisting of an Inspection and Test Plan (ITP) and Manufacturing Plan (MP) shall be developed specifically for all aspects of work and shall be approved prior to commencement of manufacturing operations. The MP shall clearly define the sequence of operations and process controls to be implemented at each operation. The minimum quality control tests to be performed shall be as indicated in Table 2. Records of all coating application and quality control test results shall be kept in accordance with (14).

10.2

IDENTIFICATION OF EPOXY POWDER RESIN The Applicator shall ensure that all materials supplied for the coating operation have been marked in accordance with (7.2.3). Material that is not marked shall be removed from the site. The Applicator shall ensure that all materials are stored according the recommended storage conditions and time. The Applicator shall check if the supplied epoxy powder is in compliance with the coating certificates. The Applicator shall at least measure the gel and cure time, thermal characteristics and moisture content of every batch.

10.3

AMBIENT CONDITIONS The Applicator shall measure the ambient conditions once every 2 hours during blasting and coating and keep records of prevailing temperature, humidity and dew point. If the conditions are outside the limits specified in this DEP, the process shall be suspended until the required conditions are met.

10.4

INSPECTION OF UNCOATED PIPES BEFORE BLASTING Before surface preparation starts, each pipe shall be visually examined for dents, laps, defective bevels and other defects to avoid the coating of unserviceable pipes. Defective pipes shall be removed from the coating line for repair or, if repair is not possible, rejected. The pipe surface shall be visually checked for contamination with salts, oil or grease. Contaminated pipes shall be cleaned again. If required by the Principal, the chloride contamination shall be checked according to (9.2.4).

10.5

INSPECTION AFTER BLASTING Pipes shall be inspected for surface cleanliness according Table 2 Pipes that do not comply with the requirements in (9.2.2) and (9.2.3) shall be rejected and blast-cleaned again. The surface profile shall be measured at regular intervals and on the first 5 pipes following each change of blast-cleaning material. If the surface roughness is outside the specified limits, the blasting material shall be checked and replaced as necessary. The affected pipes shall be re-blasted. At regular intervals, the blasted surface shall be checked for chloride contamination (9.2.4). If contamination of the surface occurs, the quality of the blasting material and process shall be examined, see (A.19). If the conductivity of the blasting material is greater than 50 µS/cm, the blasting material shall be replaced. The affected pipes shall be washed with potable water and dried.

DEP 31.40.30.32-Gen. February 2011 Page 19 Additionally, the conductivity of the abrasive material shall be checked four times per shift when no acid wash is performed and two times per shift when an acid wash is performed. The maximum allowable conductivity is 50 µS/cm. 10.6

APPLICATION TEMPERATURES The temperature of the pipe surface shall be continuously monitored and recorded by means of suitable instruments, e.g. infrared sensors, contact thermometers and thermocouples. The instruments shall be calibrated daily and verified at least twice per shift with tempil sticks. The monitoring instruments shall be independent of the temperature control equipment. The instruments shall be calibrated prior to each unit of production. Any deviation from the recommended application temperature range shall be rectified. If immediate rectification is not possible, production shall be stopped until the cause of the problem has been removed. Any pipes coated during the duration of the temperature deviation shall be identified by marking and subjected to additional quality control tests to check curing, adhesion and impact properties (10.8). Pipes that do not comply with the quality control requirements shall be rejected, cleaned and recoated. Pipe temperature shall not exceed 280 °C. Pipe heated in excess of this value or pipe with obvious blueing shall be set aside and clearly marked for final disposition by the Principal’s Representative.

10.7

APPEARANCE, THICKNESS AND HOLIDAYS Immediately following coating application, each coated pipe shall be visually checked for imperfections and irregularities of the coating, for coating thickness and for the absence of holidays. Pipes that do not comply with the requirements shall be marked and removed from the coating line for repair or recoating. If subsequent pipes do not comply with the requirements, the coating process shall be checked or stopped to remove the cause of the problem. Pipes having a coating of insufficient thickness shall not be repaired by overcoating. For a 12-m pipe length the maximum allowable number of holidays to be repaired shall be as follows (for other pipe lengths a proportional number shall be applicable): -

up to 200 mm pipe diameter 200 mm up to 600 mm pipe diameter 600 mm pipe diameter and above

: : :

4 per pipe 6 per pipe 8 per pipe.

If the number of holidays per pipe exceeds the figures stated above, the coating shall be removed and the pipe shall be re-blasted and re-coated. If two consecutive pipes are rejected for this reason, the coating process shall be checked to determine the cause of the high holiday rate. If the cause is not resolved after further rejection of consecutive joints, the complete process shall be stopped for full investigation. All holidays detected shall be repaired in accordance with the qualified repair procedure (11.2). Holidays caused by metal surface defects shall require the removal of the defect by grinding or filing of the defect prior to application of the repair material. No repairs shall be made that violate the applicable line pipe specification. Under no circumstances shall a steel defect be overcoated with repair material. Each pipe shall be checked for cleanliness of the pipe ends and damage of the bevelled ends. Damaged bevels shall be repaired by means of procedures approved by the Principal.


DEGREE OF CURE, MICROSCOPIC EXAMAMINATION, ADHESION AND IMPACT TESTING At the frequency stated in Table 2, pipes shall be randomly selected and subjected to the identified tests. After testing the coating shall be repaired in accordance with the qualified repair procedure (11.2).

10.9

FLEXIBILITY TEST, HOT WATER TEST AND CATHODIC DISBONDING TEST Test samples shall be prepared for the flexibility test, the hot water test and the cathodic disbonding test at the frequency stated in Table 2. A sample of sufficient length for all the tests shall be cut from one end of a selected pipe. After cutting of the test sample, the remaining pipe joint shall be marked with the remaining length and the coating cutback and the pipe bevel shall be reinstated as specified by the Principal. The tests shall be started as soon as possible after coating to allow for adjustment of the coating process if necessary.

10.10

ACCEPTANCE OF FAILED PIPES In the event of the test pipes/samples failing to meet the requirements of sections (10.8), and/or (10.9), preceding pipes coated after the last acceptable test pipe/sample and the pipes coated following the failed pipe shall be suspect and shall be marked for further testing. The Applicator shall propose and agree with the Principal a test programme to trace any of the suspect pipes affected by the same failure. Further testing shall involve inspection and examination similar to that carried out on the original rejected test pipe(s). Based on the test results, the final acceptance or rejection of the suspect pipes shall be made by the Principal. No pipes shall be dispatched from the coating yard before the Principal has approved the quality control results. The Principal retains the right to reject any shift’s or day’s production if the reject rate of that production is more than 10 % and/or if sample test results are found to be outside the specification in this DEP. In addition, the Applicator may be required to stop production and carry out a full investigation into the source of the problem The Applicator shall submit the results to the Principal before receiving permission from the Principal to recommence production.

10.11

TRACEABILITY OF PIPES AND COATING The Applicator shall ensure that individual pipes are fully traceable during and after the coating process. If the serial number of the pipe as given in the pipe mill is removed or obliterated, then it shall be reapplied. The Applicator’s own serial number shall be indicated on the pipe, and records shall be kept to identify the sequence and time of coating and the batch of epoxy powder used for each pipe. Internal stickers or adhesive labels inside the pipe shall not be used. Pipe traceability and identification shall be discussed during the pre-job meeting.

11.

REPAIR OF COATED PIPE

11.2

REPAIR OF HOLIDAYS Delete this clause and replace with: The Contractor shall submit detailed procedures for coating repairs. All coating repair procedures shall be qualified under both coating system qualification and Applicator qualification.

DEP 31.40.30.32-Gen. February 2011 Page 21 These procedures shall contain as a minimum: -

repair of surface defects; repair of holidays, scratches and small defects; repair of damages due to quality control testing, typically adhesion testing, film sampling and impact testing; removal of rejected coating and cleaning the pipe to the required standard for recoating; testing to prove the effectiveness of the repairs.

The maximum allowable single repair area is 25 cm2 and the maximum total surface area per pipe that may be repaired is 40 cm2. Pipes requiring larger repairs shall be re-coated. Pipes having insufficient coating thickness shall not be repaired by overcoating. All pipes that have been repaired shall be fully re-examined in accordance with the quality control procedures. Minimum quality control requirements for repairs of small defects and damages shall be identified by the Principal. Records shall be kept of all repaired pipes and shall include the repair and re-test details. 13.

HANDLING AND COATING IN THE STORAGE AREA Add the following: The Coating Contractor shall take receipt of the pipes delivered by the Line Pipe Manufacturer and shall keep a record of the serial numbers of the delivered pipes. Upon receipt, the pipes shall be inspected for transport damage or other defects. Damaged pipes shall be separately stored and reported to the Principal. Repairs shall only be carried out after approval by the Principal. During the various stages of the complete coating process, the Coating Contractor shall ensure that all pipes shall be handled, stored and transported in such a manner that no damage is caused to the pipes and the applied coating. Instructions by the Line Pipe Manufacturer and/or the Coating Manufacturer shall be followed.

13.2

STORAGE add the following: Pipes shall be stored in designated areas. Pipes shall not be stored with other consignments or pipes for other contracts. Pipes shall be stacked only to such a height that damage or deformation to the pipes due to the weight of other pipes shall not occur. Coated pipes shall be stacked only to such a height that no damage to the coating occurs. Pipe supports shall be spaced so that no bending of pipes occurs. Pipe supports shall be made of soft padded wooden bolsters or sand rows, free of stones, covered with plastic sheets. The pipe surface shall be at least 150 mm clear from the soil. Piles of pipe shall be secured by wooden wedges or ground pins, provided with adequate padding to prevent coating damage, and of sufficient size to prevent collapse of the piles. Coated pipes shall be stacked using soft separators such as rubber pads or tyre tread. It is required to have at least four separators (approved by the Principal) for every 12 m joint. When stored outdoors, pipes shall be placed at a small angle to allow drainage of any rain water from the inside of the pipes.

13.3

TRANSPORT OF COATED PIPE Coated pipes shall be prepared for transport or shipment in accordance with API RP 5L1 or API RP 5LW, whichever is applicable. During transportation, pipes shall be stacked and secured so as to prevent movement, abrasion and/or peening.

DEP 31.40.30.32-Gen. February 2011 Page 22 The coated pipes shall be inspected for damages during load-out by using the holiday detection procedure as specified in (7.4). Coating damage, if not exceeding the requirements of this DEP, shall be repaired at the Applicator’s expense. Damaged coating that exceeds the allowable limits of this DEP at load-out shall be stripped and the pipe shall be recoated at the Applicator’s expense. 14.

TEST REPORTS AND CERTIFICATE OF COMPLIANCE Add the following: The Contractor shall keep accurate records of all relevant data of the coating process. This documentation shall include: -

Copies of the coating system information; Copies of qualification information; Copies of, or reference to, all procedures for coating the pipes; Serial numbers of all pipes as given by the Line Pipe Manufacturer (e.g. by copies of the pipe mill data sheets); Serial numbers as given by the coating Applicator (if applicable) related to the Manufacturer’s serial numbers; The order of coating, the day and shift of coating of each pipe; The batch numbers of the coating materials, the day and time of loading of each batch; Serial numbers of rejected pipes and the reason for rejection; Records of any repairs; The results of all quality control testing; Records of temperatures during the coating process for each pipe, with the processing time of every tenth pipe, shall be marked on the temperature chart with the pipe number; Names and signatures of the responsible persons for the coating process and quality control.

This document shall be submitted to the Principal after completion of the coating works together with the calibration certificates of the testing and inspection instruments.


ANNEX A.4 DRY ADHESION TEST Add the following: For qualification purposes, in addition to the knife test, the adhesion strength of the coating shall be tested by a pull-off test according to ISO 4624. A.4.3.3 Delete this clause ANNEX A.9 CATHODIC DISBONDMENT OF THE COATING A.9.3.2 Amend as follows: A 6 mm diameter holiday shall be drilled in the centre of the test specimen through the coating to expose the steel substrate (see Figure A.7). A.9.3.5 Delete and replace with as follows: By means of a potentiostat, the electrochemical potential of the steel shall be polarised to -1500 mV ± 10 mV with respect to the SCE. This potential shall be maintained throughout the test. The current required to maintain the potential shall be checked and recorded daily. The duration of the test shall be 28 days, after which the sample shall be removed from the cell and examined. For quality control purposes, the duration of the test shall be 48 hours; see (8.1.1.10). For tests at elevated temperatures, the temperatures shall be controlled as follows: •

If the cell has been constructed on the pipe sample, the steel sample shall be placed in a thermostatically controlled furnace or sand bath that also covers the top surface of the sample with at least 1 cm of sand. The furnace or bath shall be adjusted to maintain the required test temperature on the pipe surface in the test defect.

•

During tests at elevated temperatures, suitable reflux coolers shall be used to prevent evaporation of the test electrolyte.

A.9.4 Add the following: -

Maximum disbonding radius (mm)

-

Photos of the exposed test specimen

ANNEX A.11

.

A.11.3.3 Delete and replace as follows: The presence of foaming and voids at the cross-section of the coating (section perpendicular to the pipe surface) and at the coating interface (section parallel to the pipe surface) shall be rated according to the pictorial scale in Figure A.10.


Figure A.10 Degree of porosity of FBE film

ANNEX A.15

.

A.15.3.1 Delete this clause and amend as follows: Fresh tap water used for each step shall be heated to test temperature related to the operating temperature as specified in Table 3, prior to immersion of the test specimens. The test specimens shall be placed in the slow cooker or water bath and submerged fully in that preheated water. The duration of the test for coating qualification shall be 28 days. For qualification testing, the adhesion of the coating system shall also be tested by the dolly pull off method, see (A.4). For quality control purposes (10.9), the duration of the hot water resistance test shall be 48 hours. A.15.3.2 Delete this clause. A.15.3.3 Delete this clause. Add ANNEX A.16: ANNEX A.16

COATING THICKNESS

The coating thickness shall be measured by means of a thickness meter based on eddy current or electromagnetic techniques in accordance with ISO 2808, method 6A or 6B. Magnetic thickness gauges shall not be used, either for qualification testing or for quality control purposes. The thickness gauge shall be calibrated at least once per shift. Calibration shall be carried out on a flat steel plate of similar thickness as the pipe wall by means of plastic shims of the same thickness (± 20 %) as the nominal coating system.

DEP 31.40.30.32-Gen. February 2011 Page 25 A minimum of twelve thickness checks shall be made at approximately one quarter, one half and three quarters of the length of each pipe and at the 3, 6, 9 and 12 o’clock positions around the pipe. For submerged arc welded pipe one of these circumferential positions shall be at the top of the weld. Add ANNEX A.17: ANNEX A.17

HOLIDAY DETECTION

A holiday test shall be performed by means of an adjustable high-voltage holiday tester having an audible and visual alarm. The scanning electrode shall consist of a metal brush or coil spring, fitting the diameter of the coated pipes. The earth connection shall be made directly on the pipe. The test voltage shall be set as per Table 5.

Table 5 Test Voltage Setting Test Voltage (kV)

Nominal Coating Thickness (µm)

2.4

475

3.6

725

The test voltage shall be calibrated at least twice per shift by means of a high-voltage meter. When the holiday test is carried out the external pipe surface shall be free of moisture. The electrode shall be moved over the pipe surface at a speed of not more than 0.3 m/s. The whole of the pipe surface shall be covered by the test. When the holiday test is used for the impact resistance test (A.13) or the flexibility test (A.12), a metal brush shall be used to inspect the treated surface. Add ANNEX A.18: ANNEX A.18

PHOSPHORIC ACID TREATMENT

ANNEX A.18.1

Scope

This section defines the minimum requirements for materials, application, testing and inspection of phosphoric acid treatment of line pipe prior to the coating application. ANNEX A.18.2

Materials

The Applicator shall obtain from the Manufacturer copies of the most recent technical data sheets describing the product, its general performance, shelf life, and application requirements. Documentation shall include MSD sheets and the Manufacturer’s recommendation for proper disposal of residues and rinsing from the pipe. The Applicator shall obtain from the Manufacturer a certification for each batch or lot of phosphoric acid to be used on the Principal’s line pipe. The Manufacturer shall define a batch. The certification shall include: Product name, designation, and batch number. Product quality control test results and ranges for: 1. chemical assay of active ingredients; 2. level of solvents or co-solvents; 3. level of surfactants.

DEP 31.40.30.32-Gen. February 2011 Page 26 The treatment materials shall be approved by the Principal prior to use. Treatment materials for use shall be: 1. In the Manufacturer’s original, unopened containers; 2. Stored in a clean, dry location according to the Manufacturer’s recommendation; 3. Clearly marked with the batch number and date of manufacture; 4. Applied within the Manufacturer’s recommended shelf life. ANNEX A.18.3

Application procedure

The phosphoric acid solution shall be applied to pipe after the surface has been blast cleaned. The phosphoric acid solution shall be applied to pipe surfaces as close to the coating application station as is practical and feasible. The phosphoric acid treatment shall be applied at an acid concentration of 10 % by volume +/- 3 %. The concentration shall be measured and recorded using a titration method recommended by the Manufacturer at a frequency of twice per shift. Pipe shall be uniformly heated (43°C to 71°C) for treatment within the maximum elapsed time after blast cleaning. The temperature shall be recorded at a frequency of twice per shift. The phosphoric acid solution shall be uniformly applied to the pipe surface and shall remain on the surface in accordance with the Manufacturer’s recommendations. The dwell time shall be recorded at a frequency of twice per shift. Pipe surfaces shall remain wet at all times during the phosphoric acid treatment. Any treated pipe joint shall be re-blasted if the acid solution is allowed to dry anywhere on the surface of that pipe joint. After the indicated dwell time, the pipe surface shall be thoroughly rinsed with deionised water having a conductivity of 10 µmhos/cm or less. The pressure and volume of rinse water used shall be sufficient to thoroughly remove the acid residue. The minimum pH of the wet surface after rinsing shall be 6.0, as determined by touching pH paper directly to the pipe surface. The pH paper shall have a measurement increment of 0.5 pH units or less. The pipe surface pH shall be recorded at a frequency of twice per shift. The appearance of the pipe surface after drying shall be substantially the same as it was immediately after blast cleaning. Occasional watermarks are permitted. Add ANNEX A.19: ANNEX A.19

CONDUCTIVITY MONITORING OF BLASTING MATERIAL EXTRACTS

This method describes the procedure for monitoring the quality of the blasting material in machines that recycle the blasting material. An increased conductivity level may indicate the introduction of an ionic contaminant in the blasting material from the pipe surface. The procedure is as follows: -

measure a 100 ml volume of blasting material in a glass bottle; add 100 ml deionised or distilled water; cap the bottle and shake for 1 min; decant the water extract into another glass bottle; measure and record the conductivity of the water at room temperature.

DEP 31.40.30.32-Gen. February 2011 Page 27 PART III REFERENCES In this DEP, reference is made to the following publications: NOTES:

1. Unless specifically designated by date, the latest edition of each publication shall be used, together with any amendments/supplements/revisions thereto. 2. The DEPs and most referenced external standards are available to Shell staff on the SWW (Shell Wide Web) at http://sww.shell.com/standards/.

AMERICAN STANDARDS Recommended practice for railroad transportation of line pipe

API RP 5L1

Recommended practice for transportation of line pipe on barges and marine vessels

API RP 5LW

Issued by: American Petroleum Institute Publications and Distribution Section 1220 L Street Northwest Washington DC 20005 USA

Application, performance, and quality control of plant-applied, fusion-bonded epoxy external pipe coating

NACE RP 0394-2002

Issued by: NACE International P.O. Box 218340 Houston, Texas 77218 USA

INTERNATIONAL STANDARDS Paints and varnishes – Determination of film thickness

ISO 2808

Paints and varnishes – Pull-off test for adhesion

ISO 4624

Preparation of steel substrates before application of paints and related products – Tests for the assessment of surface cleanliness Part 3: Assessment of dust on steel surfaces prepared for painting (pressure-sensitive tape method)

ISO 8502-3

Part 6: Extraction of soluble contaminants for analysis – The Bresle method

ISO 8502-6

Part 9: Field method for the conductometric determination of water-soluble salts

ISO 8502-9

Petroleum and natural gas industries – External coatings for buried or submerged pipelines used in pipeline transportation systems – Part 2: Fusion-bonded epoxy coatings Issued by: ISO Central Secretariat 1, ch. de la Voie-Creuse Case postale 56 CH-1211 Genève 20 Switzerland Copies can also be obtained from national standards organizations.

ISO 21809-2:2007

31403032 External Fusion-bonded Epoxy Powder Coating for Line Pipe

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