1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-23112-5 SANS 15589-2:2009Edition 1ISO 15589-2:2004Edition 1SOUTH AFRICAN NATIONAL STANDARD Petroleum and natural gas industries Cathodic p
4、rotection of pipeline transportation systems Part 2: Offshore pipelines This national standard is the identical implementation of ISO 15589-2:2004 and is adopted with the permission of the International Organization for Standardization. Published by SABS Standards Division 1 Dr Lategan Road Groenklo
5、of Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 15589-2:2009 Edition 1 ISO 15589-2:2004 Edition 1 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committee SC 59H, Construction Standards
6、 Buried or immersed metal structures, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in July 2009. This preamble outlines certain characteristics of the South African pipeline network which differ sl
7、ightly from other countries and should be taken into account when using this standard. In South Africa, due to long distances and extensive stray currents, all buried metallic pipelines (including water, oil, gas and other hazardous pipelines) need to be protected against external corrosion by the a
8、pplication of an external coating and cathodic protection (CP). Materials of construction which include metallic components (such as reinforced or pre-stressed concrete) also require careful consideration in this regard. As a result of the significant stray current interference from the DC traction
9、railway system and other CP systems, it is not always possible to achieve the criterion of -1200 mV Cu/CuSO4as the most negative limit of polarized potential on a pipeline. In new installations, due consideration should be given to coating selection to avoid detrimental effects of high negative pote
10、ntials discussed in this standard. The South African experience has shown that electrical isolation at rail crossings is not effective for stray current mitigation and should only be considered on aboveground installations. Similarly, buried pipelines should be electrically continuous in stray curre
11、nt environments, rather than being made electrically discontinuous. Insulating flanges should be colour coded red and clearly marked for safety reasons. Caution should be exercised in the use of any insulating flanges in aggressive stray current environments due to the possibility of electrolytic co
12、rrosion either side of the insulating flange. In aggressive stray current environments, the practice of bonding adjacent structures to form a common cathode has proved to be an effective means of providing protection and limiting interference. In aggressive stray current environments corrective acti
13、on where required should be implemented as soon as possible. Due to the presence of stray currents, corrosion of buried structures can happen very quickly, even during construction. For this reason, the application of effective temporary cathodic protection during construction is a vital activity. N
14、o pipe should be buried, without temporary CP. A suitable monitoring programme of the temporary CP should be implemented and maintained throughout the construction period, until the permanent CP system is energized. Monitoring of temporary CP during construction is an onerous and time consuming acti
15、vity which is critical to the long term integrity of the pipeline. CP infrastructure and components should be designed to be vandal proof. SANS 15589-2:2009 Edition 1 ISO 15589-2:2004 Edition 1 Due cognizance should be taken of the effect of stray currents on the accuracy of overline surveys, and su
16、rvey procedures may need to be modified to take these effects into account. For close interval potential surveys, static recorders should be installed simultaneously at test points where the trailing cable is connected to monitor the effect of stray currents. For DCVG surveys, simultaneous readings
17、of the signal strength at test points, as well as the overline to remote earth readings need to be taken to compensate for the effects of stray currents. The methodology for determining the severity of coating defects should be modified for the effects of stray currents otherwise the values will be
18、incorrect. As the quality of coatings improves, the effects of induced AC on pipelines which are cathodically protected are becoming more significant, both from a safety and corrosion point of view. Due consideration needs to be given to the effective draining of the AC from buried pipelines. The us
19、e of sacrificial anodes, such as zinc, for draining of AC from buried pipelines needs to be carefully considered under stray current conditions as these anodes can act as current collectors. Software for mathematical modelling of CP systems and AC mitigation is an emerging field and can be useful un
20、der certain defined conditions, but due cognizance should be taken of the limitations of the models. Reference numberISO 15589-2:2004(E)ISO 2004INTERNATIONAL STANDARD ISO15589-2First edition2004-05-01Petroleum and natural gas industries Cathodic protection of pipeline transportation systems Part 2:
21、Offshore pipelines Industries du ptrole et du gaz naturel Protection cathodique des systmes de transport par conduites Partie 2: Conduites en mer SANS 15589-2:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 15589-2:2004(E) PDF disclai
22、mer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties acc
23、ept therein the responsibility of not infringing Adobes licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the
24、file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. ISO 2004 All righ
25、ts reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the
26、 requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2004 All rights reservedSANS 15589-2:2009This s tandard may only be used and printed by approved subscription and fr
27、eemailing clients of the SABS .ISO 15589-2:2004(E) ISO 2004 All rights reserved iiiContents Page Foreword. v Introduction . vi 1 Scope 1 2 Normative references . 1 3 Terms and definitions. 2 4 Symbols and abbreviated terms 3 5 CP system requirements 3 5.1 General. 3 5.2 Selection of CP systems 4 6 D
28、esign parameters 6 6.1 General. 6 6.2 Protection potentials 7 6.3 Design life 9 6.4 Design current densities 9 6.5 Coating breakdown factors 11 7 Galvanic anodes 12 7.1 Design of system 12 7.2 Selection of anode material . 13 7.3 Electrochemical properties 13 7.4 Anode shape and utilization factor .
29、 13 7.5 Special mechanical and electrical considerations 13 8 Anode manufacturing . 14 8.1 Pre-production test . 14 8.2 Coating. 15 8.3 Anode core materials 15 8.4 Aluminium anode materials . 15 8.5 Zinc anode materials 16 9 Galvanic anode quality control 16 9.1 General. 16 9.2 Steel anode cores . 1
30、6 9.3 Chemical analysis of anode alloy 17 9.4 Anode mass. 17 9.5 Anode dimensions and straightness 17 9.6 Anode core dimensions and position. 18 9.7 Anode surface irregularities 18 9.8 Cracks 18 9.9 Internal defects, destructive testing . 19 9.10 Electrochemical quality control testing 20 10 Galvani
31、c anode installation 21 11 Impressed-current CP systems . 22 11.1 Current sources and control 22 11.2 Impressed-current anode materials 22 11.3 System design. 22 11.4 Manufacturing and installation considerations . 23 11.5 Mechanical and electrical considerations23 SANS 15589-2:2009This s tandard ma
32、y only be used and printed by approved subscription and freemailing clients of the SABS .ISO 15589-2:2004(E) iv ISO 2004 All rights reserved12 Documentation 24 12.1 Design, manufacturing and installation documentation.24 12.2 Commissioning procedures.25 12.3 Operating and maintenance manual .25 13 O
33、peration, monitoring and maintenance of CP systems 26 13.1 General .26 13.2 Monitoring plans26 13.3 Repair .26 Annex A (normative) Galvanic anode CP design procedures .27 Annex B (normative) Performance testing of galvanic anode materials 35 Annex C (normative) Monitoring of CP systems for offshore
34、pipelines .37 Annex D (informative) Laboratory testing of galvanic anodes for quality control.43 Annex E (informative) Interference .45 Annex F (informative) Pipeline design for CP48 Bibliography54 SANS 15589-2:2009This s tandard may only be used and printed by approved subscription and freemailing
35、clients of the SABS .ISO 15589-2:2004(E) ISO 2004 All rights reserved vForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO techn
36、ical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
37、with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft In
38、ternational Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document
39、may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 15589-2 was prepared by Technical Committee ISO/TC 67, Materials, equipment and offshore structures for petroleum, petrochemical and natural gas industries, Subcommittee SC 2, Pi
40、peline transportation systems. ISO 15589 consists of the following parts, under the general title Petroleum and natural gas industries Cathodic protection of pipeline transportation systems: Part 1: On-land pipelines Part 2: Offshore pipelines SANS 15589-2:2009This s tandard may only be used and pri
41、nted by approved subscription and freemailing clients of the SABS .ISO 15589-2:2004(E) vi ISO 2004 All rights reservedIntroduction Pipeline cathodic protection is achieved by the supply of sufficient direct current to the external pipe surface, so that the steel-to-electrolyte potential is lowered t
42、o values at which external corrosion is reduced to an insignificant rate. Cathodic protection is normally used in combination with a suitable protective coating system to protect the external surfaces of steel pipelines from corrosion. External corrosion control in general is covered by ISO 13623. U
43、sers of this part of ISO 15589 should be aware that further or differing requirements may be needed for individual applications. This part of ISO 15589 is not intended to inhibit alternative equipment or engineering solutions to be used for the individual application. This may be particularly applic
44、able where there is innovative or developing technology. Where an alternative is offered, any variations from this part of ISO 15589 should be identified. Deviations from this part of ISO 15589 may be warranted in specific situations, provided it is demonstrated that the objectives expressed in this
45、 part of ISO 15589 have been achieved. SANS 15589-2:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .INTERNATIONAL STANDARD ISO 15589-2:2004(E) ISO 2004 All rights reserved 1Petroleum and natural gas industries Cathodic protection of pipel
46、ine transportation systems Part 2: Offshore pipelines 1 Scope This part of ISO 15589 specifies requirements and gives recommendations for the pre-installation surveys, design, materials, equipment, fabrication, installation, commissioning, operation, inspection and maintenance of cathodic protection
47、 systems for offshore pipelines for the petroleum and natural gas industries as defined in ISO 13623. This part of ISO 15589 is applicable to carbon and stainless steel pipelines in offshore service. This part of ISO 15589 is applicable to retrofits, modifications and repairs made to existing pipeli
48、ne systems. This part of ISO 15589 is applicable to all types of seawater and seabed environments encountered in submerged conditions and on risers up to mean water level. NOTE Special conditions sometimes exist where cathodic protection is ineffective or only partially effective. Such conditions ca
49、n include elevated temperatures, disbonded coatings, thermal insulating coatings, shielding, bacterial attack, and unusual contaminants in the electrolyte. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 1461, Hot dip galvanized coatings on fabricated iron and steel articles Specifications and test methods
