BS EN 16222-2012 Cathodic protection of ship hulls《船体阴极保护》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 16222:2012Cathodic protection of shiphullsBS EN 16222:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 16222:2012.The UK participa

2、tion in its preparation was entrusted to TechnicalCommittee GEL/603, Cathodic protection.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for

3、its correctapplication. The British Standards Institution 2012. Published by BSI StandardsLimited 2012ISBN 978 0 580 72890 7ICS 47.020.01; 77.060Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Pol

4、icy and Strategy Committee on 31 October 2012.Amendments issued since publicationDate Text affectedBS EN 16222:2012EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16222 October 2012 ICS 47.020.01; 77.060 English Version Cathodic protection of ship hulls Protection cathodique des coques de batea

5、ux Kathodischer Korrosionsschutz von Schiffen This European Standard was approved by CEN on 25 August 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterat

6、ion. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC 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 b

7、y translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

8、 Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARD

9、IZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16222:2012: EBS EN 16222:2012EN 16222:2012 (E) 2 Conten

10、ts Page Foreword 4Introduction .51 Scope 61.1 General 61.2 Structures .61.3 Materials .61.4 Environment .62 Normative references 63 Terms and definitions .74 Competence of personnel .75 Design basis .85.1 General 85.2 Cathodic protection criteria 85.3 Design process 95.4 Design parameters 105.5 Curr

11、ent demand 105.6 Cathodic protection systems 135.7 Electrical continuity 145.8 Fitting out period 146 Impressed current system . 146.1 Objectives 146.2 Design considerations . 146.3 Equipment considerations . 157 Galvanic anodes system 197.1 Objectives 197.2 Design considerations . 197.3 Anode mater

12、ials 197.4 Factors determining the anode current output and operating life 207.5 Location of anodes . 208 Commissioning, Operation and Maintenance . 218.1 Objectives 218.2 Measurement Procedures 218.3 Commissioning: Galvanic Systems 218.4 Commissioning: Impressed Current Systems . 228.5 Operation an

13、d maintenance 238.6 Dry-docking period . 249 The protection of ships hulls during fitting out and when laid up . 259.1 Fitting out period 259.2 Lay up period 2510 Documentation 2510.1 Objectives 2510.2 Impressed current system . 2610.3 Galvanic anode systems 26Annex A (informative) Impressed current

14、 system for hulls of ships based on two cathodic protection zones . 28BS EN 16222:2012EN 16222:2012 (E) 3 Annex B (informative) Guidance on design current values for cathodic protection of hulls of ships 29B.1 Typical design current densities for the cathodic protection of bare steel (Jb) 29B.2 Coat

15、ing breakdown of conventional paint systems (fc) . 29B.3 Typical current densities for global approach of the cathodic protection of coated ships (Jg) . 30Annex C (informative) Anode resistance, current and life duration formulae 31C.1 Anode resistance formulae 31C.2 Calculation of the anode resista

16、nce at the end of life . 32C.3 Electrolyte resistivity 33C.4 Galvanic anode current output 35C.5 Anode life . 35C.6 Minimum Net Weight Requirement 35Annex D (informative) Electrical bonding systems . 37Annex E (informative) Monitoring of electrical bonding of a ships propeller 39Annex F (informative

17、) Impressed current system for ships based on an aft (stern) system only . 40Annex G (informative) Location of galvanic anodes in the stern area 41Annex H (informative) Electrochemical characteristics of impressed current anodes . 42Annex I (informative) Cofferdam arrangements . 43Annex J (informati

18、ve) Cathodic protection of a moored ship using suspended galvanic anodes 45Bibliography 46BS EN 16222:2012EN 16222:2012 (E) 4 Foreword This document (EN 16222:2012) has been prepared by Technical Committee CEN/TC 219 “Cathodic protection”, the secretariat of which is held by BSI. This European Stand

19、ard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2013, and conflicting national standards shall be withdrawn at the latest by April 2013. Attention is drawn to the possibility that some of the elements of this

20、document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standa

21、rd: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spai

22、n, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 16222:2012EN 16222:2012 (E) 5 Introduction Cathodic protection is usually applied, mostly as a complement to protective coatings, to protect the external surfaces of ship hulls and immersed appurtenances from corrosion due to seawater. Cat

23、hodic protection works by supplying sufficient direct current to the immersed external surface of the structure in order to change the steel to electrolyte potential to values where corrosion is insignificant. The general principles of cathodic protection are detailed in EN 12473. BS EN 16222:2012EN

24、 16222:2012 (E) 6 1 Scope 1.1 General This European Standard defines the general criteria and recommendations for cathodic protection of immersed external ship hulls and appurtenances. This European Standard does not cover safety and environmental protection aspects associated with cathodic protecti

25、on. Relevant national or international regulations and classification society requirements apply. 1.2 Structures This European Standard covers the cathodic protection of the underwater hulls of ships, boats and other self propelled floating vessels generally used in seawater together with their appu

26、rtenances such as rudders, propellers, shafts and stabilisers. It also covers the cathodic protection of thrusters, sea chests and water intakes (up to the first valve). It does not cover the protection of internal surfaces such as ballast tanks. It does not cover steel offshore floating structures

27、which are covered in EN 13173. 1.3 Materials This European Standard covers the cathodic protection of ship hulls fabricated principally from carbon manganese steels including appurtenances of other ferrous or non-ferrous alloys such as stainless steels and copper alloys, etc. This European Standard

28、applies to both coated and bare hulls; most hulls are coated. The cathodic protection system should be designed to ensure that there is a complete control over any galvanic coupling. This European Standard does not cover the cathodic protection of hulls principally made of other materials such as al

29、uminium alloys, stainless steels or concrete. 1.4 Environment This European Standard is applicable to the hull and appurtenances in seawater and all waters which could be found during a ships world-wide deployment. 2 Normative references The following documents, in whole or in part, are normatively

30、referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12473, General principles of cathodic protection in sea water EN 1

31、2496, Galvanic anodes for cathodic protection in seawater and saline mud EN 13509, Cathodic protection measurement techniques EN 50162, Protection against corrosion by stray current from direct current systems BS EN 16222:2012EN 16222:2012 (E) 7 EN ISO 8044, Corrosion of metals and alloys Basic term

32、s and definitions (ISO 8044) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN ISO 8044, EN 12473 and the following apply. 3.1 immersed zone zone located below the water line at draught corresponding to normal working conditions 3.2 underwater hull part

33、 of the hull vital for its stability and buoyancy of a ship Note 1 to entry: Part of the underwater hull might include that below the light water line. 3.3 boot topping section of the hull between light and fully loaded conditions which may be intermittently immersed 3.4 cathodic protection zone par

34、t of the structure which can be considered independently with respect to cathodic protection design Note 1 to entry: A single zone may comprise a variety of components with differing design parameters. 3.5 submerged zone zone including the immersed zone and the boot topping 3.6 driving voltage diffe

35、rence between the structure/electrolyte potential and the anode/electrolyte potential when the cathodic protection is operating 3.7 closed circuit potential potential measured at a galvanic anode when a current is flowing in between the anode and the surface being protected 4 Competence of personnel

36、 Personnel who undertake the design, supervision of installation, commissioning, supervision of operation, measurements, monitoring and supervision of maintenance of cathodic protection systems shall have the appropriate level of competence for the tasks undertaken. This competence should be indepen

37、dently assessed and documented. EN 15257 constitutes a suitable method of assessing and certifying competence of cathodic protection personnel which may be utilised. Competence of cathodic protection personnel to the appropriate level for tasks undertaken should be demonstrated by certification in a

38、ccordance with EN 15257 or by another equivalent prequalification procedure. BS EN 16222:2012EN 16222:2012 (E) 8 5 Design basis 5.1 General The objective of a cathodic protection system is to deliver sufficient current to protect each part of the structure and appurtenances and distribute this curre

39、nt so that the structure to electrolyte potential of each part of the structure is within the limits given by the protection criteria (see 5.2). Potentials should be as uniform as possible over the whole submerged surfaces. This objective may only be approached by adequate distribution of the protec

40、tive current over the structure during its normal service conditions. This may be difficult to achieve in some areas such as water intakes, thrusters, sea chests, where specific provisions should be considered. The cathodic protection system for a ship is generally combined with a protective coating

41、 system, even though some appurtenances such as propellers are generally not coated. Electrochemical anti-fouling systems are often used within sea chests to prevent fouling of seawater intake systems. The possibility of interaction between the anti-fouling system and the cathodic protection system

42、should be considered in the design and installation of the anti-fouling system. Cathodic protection within sea chests may adversely affect, by stray current interaction, box coolers in sea chests (typically copper nickel alloy tubes) if the box coolers are electrically isolated from the sea chest. T

43、he possibility of interaction should be taken into account in designing the cathodic protection requirements for the sea chest. The cathodic protection system should be designed either for the life of the ship or on the basis of the dry-docking intervals. The above objectives shall be achieved by th

44、e design of a cathodic protection system using galvanic anodes, an impressed current system or a combination of both. The design, the installation, the energising, the commissioning, the long-term operation and the documentation of all of the elements of cathodic protection systems shall be fully re

45、corded. EN ISO 9001 constitutes a suitable Quality Management Systems Standard which may be utilised. Each element of the work shall be undertaken in accordance with a fully documented quality plan. Each stage of the design shall be checked and the checking shall be documented. Each stage of the ins

46、tallation, energising, commissioning and operation shall be the subject of appropriate visual, mechanical and/or electrical testing and all testing shall be documented. All test instrumentation shall have valid calibration certificates traceable to national or European Standards of calibration. The

47、documentation shall constitute part of the permanent records for the works. 5.2 Cathodic protection criteria The criteria for cathodic protection are detailed in EN 12473. To achieve an adequate cathodic protection level, steel structures should have potentials as follows. The accepted criterion for

48、 protection of steel in aerated seawater is a protection potential more negative than 0,80 V measured with respect to Ag/AgCl/seawater reference electrode. This corresponds approximately to + 0,23 V when measured with respect to pure zinc electrode (e.g. alloy type Z2 as defined in EN 12496) or BS E

49、N 16222:2012EN 16222:2012 (E) 9 + 0,25 V when measured with respect to zinc electrode made with galvanic anode alloy types Z1, Z3 or Z4 as defined in EN 12496. A negative limit of 1,10 V with respect to Ag/AgCl/seawater reference electrode is generally recommended in order to avoid coating disbondment and / or increase in fatigue propagation rates. Wh