SANS 53509-2009 Cathodic protection measurement techniques《阴极保护测量技术》.pdf

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 978-0-626-23129-3 SANS 53509:2009Edition 1EN 13509:2003Edition 1SOUTH AFRICAN NATIONAL STANDARD Cathodic protection measurement techniques This nati

4、onal standard is the identical implementation of EN 13509:2003 and is adopted with the permission of CEN, rue de Stassart 36, B-1050 Brussels. Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS

5、 SANS 53509:2009 Edition 1 EN 13509:2003 Edition 1 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committee SABS SC 59H, Construction standards Buried or immersed metal structures, in accordance with procedures of the SABS Standards Divi

6、sion, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in September 2009. EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 13509May 2003ICS 25.220.40; 77.060English versionCathodic protection measurement techniquesTechniques de mesures applicables en protectionc

7、athodiqueMessverfahren fr den kathodischen KorrosionsschutzThis European Standard was approved by CEN on 27 December 2002.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard withou

8、t any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by

9、 translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Hungary, Iceland,

10、Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and UnitedKingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2003 CEN All rights of exp

11、loitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 13509:2003 ESANS 53509:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 13509:2003 (E)2Contents PageForeword . 3Introduction 41 Scope 52 Norma

12、tive references 53 Terms, definitions and symbols 53.1 Terms and definitions. 53.2 Symbols . 94 Buried structure to electrolyte potential. 104.1 Electrical equipment . 104.2 Potential measurement. 104.3 Factors influencing the potential measurement 114.4 Potential measurement techniques. 134.4.1 Mea

13、suring technique including IR drop (on potential measurement). 134.4.2 Measuring techniques to determine IR free potentials (Eir free). 135 Immersed structure to electrolyte potential . 165.1 Electrical equipment . 165.2 Potential measurements. 165.2.1 Direct potential measurement methods 165.2.2 In

14、direct potential measurement method. 176 Other measurements 176.1 Current measurements (d.c.) . 176.2 Isolating joints. 176.3 Foreign structures. 186.4 Coating . 18Annex A (informative) Table A.1 - Electrodes for Potential Measurements in Soil and/orAqueous Media 19Annex B (informative) Current redu

15、ction technique . 20Annex C (informative) Above ground surveys used to measure pipe to soil potential alonga buried pipeline 22Annex D (informative) Above ground surveys used to assess the coating condition and tolocate coating defects. 23Annex E (informative) Special off potential measurements in s

16、tray currents areas . 25Annex F (informative) Explanatory note on the use of the intensive measurementtechnique and the calculation of the IR free potential (EIR free) . 26Annex G (informative) Examples of typical coupons and external potential test probe forpipe . 28Annex H (normative) Accuracy of

17、potential measuring equipment. 29Annex I (informative) Accuracy of current measurement. 31Annex J (informative) Evaluation of the resistance of isolating joints . 33Annex K (informative) Current injection test on isolating joints . 35Bibliography . 37SANS 53509:2009This s tandard may only be used an

18、d printed by approved subscription and freemailing clients of the SABS .EN 13509:2003 (E)3ForewordThis document (EN 13509:2003) has been prepared by Technical Committee CEN/TC 219 “Cathodicprotection“, the secretariat of which is held by BSI.This European Standard shall be given the status of a nati

19、onal standard, either by publication of anidentical text or by endorsement, at the latest by November 2003, and conflicting national standardsshall be withdrawn at the latest by November 2003.This European Standard should be considered as a basic document developing generalmeasurement techniques app

20、licable for the protection of buried or immersed metallic structures.Annexes A, B, C, D, E, F, G, I, J and K are informative.Annex H is normative.This document includes a Bibliography.According to the CEN/CENELEC Internal Regulations, the national standards organizations of thefollowing countries ar

21、e bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg,Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and the UnitedKingdom.SANS 53509:2009This s tandard may onl

22、y be used and printed by approved subscription and freemailing clients of the SABS .EN 13509:2003 (E)4IntroductionThis European Standard describes the principles of the different methods of measurement used toassist in the design of the cathodic protection system of a buried or immersed metallic str

23、ucture, forthe verification of its effectiveness and finally for its optimum operational conditions.It deals in particular with the measurement of the structure to electrolyte potential, which indicateswhether or not the cathodic protection criterion for the structure is met.Apart from specifying th

24、e factors, which may influence the measurement of the potential, thisEuropean Standard describes the different techniques possible and their suitability in varioussituations.Further, this European Standard provides parameters to be controlled and measurements to becarried out (potential, potential g

25、radient, current and resistance measurements) to ensure the correctfunctioning of the cathodic protection system and its effectiveness for the entire structure.Several measurement methods described in general terms in the body of the standard are explainedin more detail in annexes. These methods dif

26、fer from one another to account for differences in type orstate of the structure, the local environment and the degree of accuracy selected.Measurements on buried structures that are not easily accessible e.g. pipe networks in urban areasare difficult to implement and interpret. To take measurements

27、 without the full knowledge of theproblems associated with the measurement technique renders the interpretation of the measurementsdifficult and leads to incorrect decisions.One of the clauses of this European Standard therefore outlines the difficulties encountered whenmeasuring structure to electr

28、olyte potentials, and suggests several methods of measurement that takeinto account, or avoid, these difficulties.Based on knowledge and experience, the most suitable measurement techniques can be selected asdescribed in this European Standard.In order to achieve effective and efficient cathodic pro

29、tection, measurements should be performed bytrained, experienced and responsible personnel.Instrumentation used for measurement should be kept in good working order and should be subjectedto periodical calibration and safety checks.SANS 53509:2009This s tandard may only be used and printed by approv

30、ed subscription and freemailing clients of the SABS .EN 13509:2003 (E)51 ScopeThis European Standard deals with the cathodic protection against corrosion of buried or immersedmetallic structures, detailing the measuring methods to be used for assessing the effectiveness ofcathodic protection as well

31、 as the measurements and measures taken to monitor cathodic protectionduring operation.Throughout the text, the measurement techniques are described primarily for pipelines.However, they are sufficiently general to apply to other kinds of buried or immersed (except offshore)structures.General princi

32、ples with regard to cathodic protection are described in EN 12954. Other measurementmethods specific to particular cases are described in other European Standards e.g. prEN 50162.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from otherpublication

33、s. These normative references are cited at the appropriate places in the text, and thepublications are listed hereafter. For dated references, subsequent amendments to or revisions of anyof these publications apply to this European Standard only when incorporated in it by amendment orrevision. For u

34、ndated references the latest edition of the publication referred to applies (includingamendments).EN 12954:2001, Cathodic protection of buried or immersed metallic structures General principlesand application for pipelinesEN ISO 8044:1999, Corrosion of metals and alloys Basic terms and definitions (

35、ISO 8044:1999)3 Terms, definitions and symbols3.1 Terms and definitionsFor the purposes of this European Standard the following terms and definitions apply. For other termsand definitions related to corrosion refer to EN ISO 8044:1999 and to cathodic protection refer toEN 12954:2001.3.1.1anode backf

36、illmaterial with a low resistivity, which may be moisture-retaining, immediately surrounding a buriedanode for the purpose of decreasing the effective resistance of the anode to the electrolyte3.1.2backfillsee anode backfill3.1.3bondmetal conductor, usually of copper, connecting two points on the sa

37、me or on different structuresusually with the intention of making the points equipotentialSANS 53509:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 13509:2003 (E)63.1.4buried structureany metal construction built or laid beneath groun

38、d level or built on ground level and then coveredwith earth3.1.5calomel reference electrodereference electrode consisting of mercury and mercurous chloride in a solution of potassium chloride3.1.6cathodic protection systementire installation, including active and passive elements, that provides cath

39、odic protection3.1.7cell currentcurrent flowing in a corrosion cell3.1.8coating defectdeficiency in the protective coating (e.g. holidays, porosity)3.1.9coating resistance or structure to soil resistance (Rco)electrical resistance between a coated metal and the electrolyte expressed in ohms. It is d

40、eterminedlargely by the size and number of coating defects, coating pores and the electrolyte resistivity3.1.10copper/saturated copper sulphate reference electrodereference electrode consisting of copper in a saturated solution of copper sulphate3.1.11couponrepresentative metal sample used to quanti

41、fy the extent of corrosion or the effectiveness of appliedcathodic protection3.1.12d.c. traction systemelectrical traction system powered by direct currentNOTE If these systems have the return circuit earthed at more than one point or are not completely isolatedthey can generate stray currents, whic

42、h may cause corrosion damage.3.1.13d.c. industrial plantelectrical system, other than a traction system, powered by direct currentNOTE If these systems use the earth as a part of the return circuit, they can generate stray currents, whichmay cause corrosion damage. Cathodic protection systems use th

43、e earth as a part of the circuit.3.1.14electrolyteliquid, or the liquid component in a medium such as soil, in which electric current flows by themovement of ions3.1.15electrolyte resistivity (r )the specific electric resistance of the electrolyte assuming that the electrolyte is homogeneousNOTE Usu

44、ally expressed in W m.SANS 53509:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 13509:2003 (E)73.1.16equalising currentscurrents that flow between areas of different polarisation after switching off the protection current.Equalising c

45、urrents can be a source of error in measuring IR free potentials3.1.17external potential test probeinstallation comprising a coupon with an associated reference electrode to provide structure toelectrolyte potential measuring facilities devoid of IR drop errors3.1.18foreign anodesee Foreign Electrod

46、e3.1.19foreign cathodesee Foreign Electrode3.1.20foreign electrodeforeign electrode is either a foreign anode or a foreign cathode. A foreign anode is a metal or aconductive material in contact with the structure under consideration which has a more negativepotential than the structure and a foreign

47、 cathode is a metal or a conductive material in contact withthe structure under consideration, which has a more positive potential than the structure3.1.21foreign structuresany neighbouring structure other than the structure that is under consideration3.1.22galvanic anodeanode that provides cathodic

48、 protection current by means of galvanic action3.1.23holidaydefect in a protective coating at which metal is exposed to the environment3.1.24immersed structureany metal construction, or part of a construction laid in a liquid environment such as fresh water(rivers, lakes), brackish water (estuaries)

49、, or sea water3.1.25insulated flangeflanged joint between adjacent lengths of pipe in which the nuts and bolts are electrically insulatedfrom one or both of the flanges and the gasket is non-conducting, so that there is an electricaldiscontinuity in the pipeline at that point3.1.26interferenceany change of the structure to electrolyte potential, which is caused by foreign electrical sources3.1.27IR dropvoltage, due to any current, developed in an electrolyte such as the soil, between the referenceelectrode and the metal of the structure, in accordance with Ohms Law (U = I .R