BS EN 13636-2004 Cathodic protection of buried metallic tanks and related piping《地下金属罐和相关管道的阴极保护》.pdf

1、BRITISH STANDARD BS EN 13636:2004 Cathodic protection of buried metallic tanks and related piping The European Standard EN 13636:2004 has the status of a British Standard ICS 23.020.10; 77.060 BS EN 13636:2004 This British Standard was published under the authority of the Standards Policy and Strate

2、gy Committee on 5 August 2004 BSI 5 August 2004 ISBN 0 580 44225 X National foreword This British Standard is the official English language version of EN 13636:2004. It partially supersedes BS 7361-1:1991, Code of practice for land and marine applications, which will be withdrawn when all the CEN st

3、andards relating to cathodic protection currently being prepared are published. The UK participation in its preparation was entrusted to Technical Committee GEL/603, Cathodic protection, which has the responsibility to: A list of organizations represented on this committee can be obtained on request

4、 to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Elec

5、tronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to

6、understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document com

7、prises a front cover, an inside front cover, the EN title page, pages 2 to 42, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROP

8、ENNE EUROPISCHENORM EN13636 July2004 ICS23.020.10;77.060 Englishversion Cathodicprotectionofburiedmetallictanksandrelatedpiping Protectioncathodiquedesrservoirsmtalliquesenterrs etconduitesassocies KathodischerKorrosionsschutzvonunterirdischen metallenenTankanlagenundzugehrigenRohrleitungen ThisEuro

9、peanStandardwasapprovedbyCENon3November2003. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtain

10、edonapplicationtotheCentralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions.

11、 CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMI

12、TTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN13636:2004:EEN 13636:2004 (E) 2 Contents Page Foreword. 5 1 Scope 6 2 N

13、ormative references . 6 3 Terms and definitions. 8 4 Criteria for cathodic protection . 9 5 Prerequisites for the application of cathodic protection 9 5.1 General. 9 5.2 Electrical continuity 10 5.3 Electrical separation. 10 5.4 External coating 10 6 Base data for design. 11 6.1 General. 11 6.2 Neig

14、hbouring structures 11 6.3 Soil environment . 11 6.4 Tank and piping data 11 6.4.1 General. 11 6.4.2 Stored medium 12 7 Design and prerequisites . 12 7.1 Structure materials . 12 7.2 Electrical separation. 13 7.2.1 General. 13 7.2.2 Isolating devices . 13 7.2.3 Temporary connections . 13 7.2.4 Perma

15、nently connected electrical equipment . 13 7.3 Explosion hazard prevention. 14 7.3.1 General. 14 7.3.2 Electrical equipment installation. 14 7.3.3 Isolating joints. 14 7.4 Other equipment . 15 7.4.1 Test station 15 7.4.2 Coupons. 16 7.4.3 Mechanical connections including flanges 16 7.4.4 Sleeve pipe

16、 16 7.4.5 Wall entries 16 7.4.6 Drainage station 16 7.4.7 Local earthing systems 16 7.5 Galvanic anode systems 16 7.5.1 General. 16 7.5.2 Materials. 17 7.5.3 Location . 17 7.5.4 Connection of anodes to the structure. 17 7.6 Impressed current systems . 17 7.6.1 General. 17 7.6.2 Components 17 7.7 Cab

17、les. 18 7.8 Interference 19 8 Installation of cathodic protection systems.19 8.1 General. 19 EN 13636:2004 (E) 3 8.2 Installation of cables. 20 8.2.1 General. 20 8.2.2 Cable connections to structures . 20 8.3 Installation of structures to be protected. 21 8.3.1 Buried structures 21 8.3.2 Above-groun

18、d structures. 21 8.3.3 Isolating joints. 21 8.4 Anodes . 22 8.4.1 General. 22 8.4.2 Galvanic anodes 22 8.4.3 Impressed current anodes . 22 8.5 Impressed current station 23 8.5.1 Location . 23 8.5.2 Electrical installation 23 8.6 Test stations, measuring points and coupons 23 8.7 Bondings and drainag

19、e stations . 23 8.8 Labelling 23 8.9 Installation checks 24 8.10 As-built documentation 24 9 Commissioning . 24 9.1 Preliminary checking 24 9.2 Start-up. 25 9.3 Verification of the cathodic protection effectiveness . 25 9.4 Determination of relevant measuring points . 25 9.5 Commissioning documents.

20、 26 10 Inspection and maintenance 26 10.1 General. 26 10.2 Inspection 26 10.2.1 General. 26 10.2.2 Functional checks of equipment . 27 10.2.3 Structure measurements 27 10.2.4 Inspection intervals 27 10.2.5 Inspection report. 29 10.3 Maintenance 29 10.3.1 Cathodic protection equipment. 29 10.3.2 Inst

21、rumentation . 29 Annex A (informative) Electrical separation between the structure to be cathodically protected and the general earthing system . 30 A.1 Isolation of electrical equipment . 30 A.2 Electrical equipment of protection class II or III (double isolation). 31 A.3 Fault current breaker with

22、 local earthing system 32 A.4 Isolating transformer 33 A.5 Example with d.c. decoupling unit 34 Annex B (informative) Groundbed data 35 B.1 General considerations 35 B.2 Type of groundbed 35 B.2.1 General . 35 B.2.2 Remote located groundbed . 35 B.2.3 Close located groundbed. 35 B.3 Anode type. 36 B

23、.3.1 High-silicon cast iron anodes 36 B.3.2 Mixed-metal oxide anodes . 37 Annex C (informative) Extract of pr EN 50162 . 38 Annex D (informative) Determination of inspection interval 39 D.1 General. 39 D.2 Complexity of the cathodic protection system 39 EN 13636:2004 (E) 4 D.3 Coating imperfections

24、39 D.4 Environmental conditions 40 D.5 Susceptibility to damage by lightning or mechanical impact 41 D.6 Risk of personal injury, environmental pollution or damage to property that could be caused by leakage of stored medium 41 Bibliography . 42 EN 13636:2004 (E) 5 Foreword This document EN 13636:20

25、04 has been prepared by Technical Committee CEN/TC 219 “Cathodic protection”, the secretariat of which is held by BSI. This document shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2005, and conflicting national

26、 standards shall be withdrawn at the latest by January 2005. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,

27、Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. This document, which deals with buried metallic tanks and associated piping, takes into account the speci

28、fic features of buried tanks in terms of construction, electrical equipment and safety considerations. The present document only covers the technical aspects of corrosion protection of tanks and associated piping. The application of cathodic protection depends on national requirements and the factor

29、s outlined in EN 12954:2001, Clause 5. EN 12954, also prepared by CEN TC 219/WG1, is concerned with cathodic protection against corrosion of buried or immersed metallic structures and gives general principles applicable to the protection of all types of such structures. Cathodic protection is a tech

30、nique based on the application of electrochemical principles and covers a wide variety of materials and equipment together with a variety of measurement techniques. It is assumed in the drafting of this document that the design, installation, commissioning, inspection and maintenance are entrusted t

31、o adequately trained, experienced, competent and reliable personnel in order to achieve effective and efficient cathodic protection. EN 13636:2004 (E) 6 1 Scope This document specifies the principles for the implementation of a system of cathodic protection against corrosive attacks on buried metal

32、tanks and associated piping. This document specifies conditions and parameters to be met in order to achieve cathodic protection, as well as rules and procedures for the design, installation, commissioning and maintenance for the protection of buried metal tanks and associated piping. This document

33、is applicable to the external surfaces of buried metallic tanks and associated buried piping. NOTE The protection of internal surfaces is covered by EN 12499. This document is applicable to buried tanks and associated piping, even if they are earthed by their own local earthing device, which are ele

34、ctrically separated from any general earthing systems and other buried structures. Therefore tanks which are covered by the present document include: industrial storage tanks, irrespective of their dimensions and the nature of the stored medium (liquid or gas, flammable or not, toxic or non-toxic, p

35、olluting or not); tanks used at petrol stations and on domestic or commercial premises, which contain flammable liquids or gases or polluting substances. This document is not applicable to: above-ground storage tank floors in contact with the ground; reinforced concrete containers; buried storage ta

36、nks that are electrically connected to the whole or a part of an industrial complex; buried storage tanks electrically connected to any general earthing systems. NOTE Cathodic protection of the last two types of tanks is covered by prEN 14505. Measurement techniques are described in detail in EN 135

37、09. 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. EN 12954:2001, Cathodi

38、c protection of buried or immersed metallic structures General principles and application for pipelines. prEN 14505:2002, Cathodic protection of complex structures. EN 50014, Electrical apparatus for potentially explosive atmospheres General requirements. EN 50016, Electrical apparatus for potential

39、ly explosive atmospheres Pressurized apparatus “p”. EN 13636:2004 (E) 7 EN 50017, Electrical apparatus for potentially explosive atmospheres Powder filling “q”. EN 50018, Electrical apparatus for potentially explosive atmospheres Flameproof enclosures “d”. EN 50019, Electrical apparatus for potentia

40、lly explosive atmospheres Increased safety “e”. EN 50020, Electrical apparatus for potentially explosive atmospheres Intrinsic safety “i”. EN 50021, Electrical apparatus for potentially explosive atmospheres Types of protection “n”. EN 50028, Electrical apparatus for potentially explosive atmosphere

41、s Encapsulation “m”. EN 50039, Electrical apparatus for potentially explosive atmospheres Intrinsically safe electrical systems “i”. EN 50162:2003, Protection against corrosion by stray current from direct current systems. EN 60079-10, Electrical apparatus for explosive gas atmospheres Part 10: Clas

42、sification of hazardous areas (IEC 6007910:1995). EN 60742, Isolating transformers and safety isolating transformers Requirements (IEC 60742:1983 + A1:1992, modified). EN 61140, Protection against electric shock Common aspects for installation and equipment (IEC 61140:2001). EN ISO 8044:1999, Corros

43、ion of metals and alloys Basic terms and definitions (ISO 8044:1999). IEC 60587, Methods for evaluating resistance to tracking and erosion of electrical insulating materials used under severe ambient conditions. EN 13636:2004 (E) 8 3 Terms and definitions For the purposes of this document, the terms

44、 and definitions given in EN 12954, EN 60079-10, EN ISO 8044 and the following apply. 3.1 electrical connection (electrically connected) connection allowing the flow of electrons between two different metallic structures Figure 1 Example of bonding permitting flow of current 3.2 electrical separatio

45、n (electrically separated) separation of two different metallic structures to prevent the flow of electrons between them Figure 2 Example of isolation to prevent the flow of currrent 3.3 associated piping all metallic process piping that is electrically connected to a buried tank and is protected by

46、 the cathodic protection system of the tank 3.4 local earthing system local earthing system for the structure under consideration which is electrically separated from any other general earthing e.g. welding metallic bond or cable Structure 1 Structure 2 Structure 1 Structure 2 Structure 1 Structure

47、2 Structure 1 Structure 2 Structure 1 Structure 2 Isolating material EN 13636:2004 (E) 9 3.5 shield conductive or non conductive structure or object, which modifies the protection current distribution on a structure to be protected 4 Criteria for cathodic protection The metal to electrolyte potentia

48、l at which the corrosion rate is 0,01 mm per year is the protection potential, Ep. This corrosion rate is sufficiently low so that during the design lifetime corrosion damage cannot occur. The criterion for cathodic protection is therefore: E Ep where E is the metal to electrolyte potential For carbon steel in soils with resistivities of 100 m and in the absence of sulfate reducing bacteria, the protection potential versus a Cu/CuSO 4saturated reference electrode, E p, , is -0,85 V. Special measures in accordance with EN 12954:2001, Table