1、 Standard Practice Pipeline External Corrosion Confirmatory Direct Assessment This NACE International (NACE) standard represents a consensus of those individual members who have reviewed this document, its scope, and provisions. Its acceptance does not in any respect preclude anyone, whether he has
2、adopted the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not in conformance with this standard. Nothing contained in this NACE standard is to be construed as granting any right, by implication or otherwise, to manufacture, sell, or use in co
3、nnection with any method, apparatus, or product covered by Letters Patent, or as indemnifying or protecting anyone against liability for infringement of Letters Patent. This standard represents minimum requirements and should in no way be interpreted as a restriction on the use of better procedures
4、or materials. Neither is this standard intended to apply in all cases relating to the subject. Unpredictable circumstances may negate the usefulness of this standard in specific instances. NACE assumes no responsibility for the interpretation or use of this standard by other parties and accepts resp
5、onsibility for only those official NACE interpretations issued by NACE in accordance with its governing procedures and policies which preclude the issuance of interpretations by individual volunteers. Users of this NACE standard are responsible for reviewing appropriate health, safety, environmental
6、, and regulatory documents and for determining their applicability in relation to this standard prior to its use. This NACE standard may not necessarily address all potential health and safety problems or environmental hazards associated with the use of materials, equipment, and/or operations detail
7、ed or referred to within this standard. Users of this NACE standard are also responsible for establishing appropriate health, safety, and environmental protection practices, in consultation with appropriate regulatory authorities if necessary, to achieve compliance with any existing applicable regul
8、atory requirements prior to the use of this standard. CAUTIONARY NOTICE: NACE international standards are subject to periodic review, and may be revised or withdrawn at any time in accordance with NACE technical committee procedures. NACE International requires that action be taken to reaffirm, revi
9、se, or withdraw this standard no later than five years from the date of initial publication. The user is cautioned to obtain the latest edition. Purchasers of NACE International standards may receive current information on all standards and other NACE International publications by contacting the NAC
10、E International FirstService Department, 1440 South Creek Dr., Houston, Texas 77084-4907 (telephone +1 281-228-6200). Approved 2010-10-22 NACE International 1440 South Creek Dr. Houston, Texas 77084-4906 +1 281-228-6200 ISBN 1-57590-240-0 2010, NACE International NACE SP0210-2010 Item No. 21148 SP02
11、10-2010 NACE International i _ Foreword This standard covers the NACE external corrosion confirmatory direct assessment (ECCDA) process for buried onshore ferrous piping systems. This standard is intended to serve as a guide for applying the NACE ECCDA process on previously assessed typical pipeline
12、 systems. ECCDA as described in this standard practice is specifically intended to address buried onshore pipelines constructed from ferrous materials. Users of this standard must be familiar with all applicable pipeline safety regulations for the jurisdiction in which the pipeline operates. This in
13、cludes all regulations requiring specific pipeline integrity assessment practices and programs. This standard is intended for use by pipeline operators and others who must manage pipeline integrity. This standard was prepared by Task Group (TG) 377, “Pipeline External Corrosion Confirmatory Direct A
14、ssessment.” TG 377 is administered by Specific Technology Group (STG) 35, “Pipelines, Tanks, and Well Casings.” This standard is issued by NACE International under the auspices of STG 35. In NACE standards, the terms shall, must, should, and may are used in accordance with the definitions of these t
15、erms in the NACE Publications Style Manual. The terms shall and must are used to state a requirement, and are considered mandatory. The term should is used to state something good and is recommended, but is not considered mandatory. The term may is used to state something considered optional. _ SP02
16、10-2010 ii NACE International _ NACE International Standard Practice Pipeline External Corrosion Confirmatory Direct Assessment Contents 1. General 1 2. Definitions 6 3. Preassessment 9 4. Indirect Inspection . 20 5. Direct Examination 25 6. Post Assessment . 32 7. ECDA Records 35 References 37 FIGU
17、RES Figure 1(a): External Corrosion Confirmatory Direct Assessment FlowchartPart 1 . 3 Figure 1(b): External Corrosion Confirmatory Direct Assessment FlowchartPart 2 . 4 Figure 1(c): External Corrosion Confirmatory Direct Assessment FlowchartPart 3 . 5 Figure 2Preassessment Step 10 Figure 3Example S
18、election of Indirect Inspection Tools . 18 Figure 4Example Definitions of ECCDA Regions . 19 Figure 5Indirect Inspection Step 21 Figure 6Direct Examination Step . 26 Figure 7Adjustment/Confirmation of Assumed Corrosion Rate 34 TABLES Table 1ECCDA Data Elements . 11 Table 2ECCDA Tool Selection Matrix
19、 . 17 Table 3Example Severity Classification Criteria . 24 Table 4Example Prioritization Criteria for Indirect Inspection Indications . 28 _ SP0210-2010 NACE International 1 _ Section 1: General 1.1 Introduction 1.1.1 This standard covers the NACE external corrosion confirmatory direct assessment (E
20、CCDA) process for buried onshore ferrous piping systems. This standard is intended to serve as a guide for applying the NACE ECCDA process on typical pipeline systems. 1.1.2 This standard was written to provide flexibility for an operator to tailor the process to specific pipeline situations. 1.1.3
21、ECCDA is a continuous improvement process. Through successive applications, ECCDA should confirm conclusions drawn from previous assessments and identify and address locations at which corrosion activity has occurred, is occurring, or may occur. 1.1.3.1 ECCDA provides the advantage and benefit of lo
22、cating areas where corrosion is likely to occur in the future rather than only areas where corrosion has already occurred. 1.1.3.2 Comparing the results of successive ECCDA applications is one method of evaluating the effectiveness of the ECCDA process, as well as the external corrosion direct asses
23、sment (ECDA) process, and demonstrating that confidence in the integrity of the pipeline is continuously improving. 1.1.4 ECCDA was developed as a process for improving pipeline safety. If external corrosion is a threat to be evaluated, ECCDA can be used to validate previous assessment conclusions o
24、r determine whether the reassessment interval is still appropriate. 1.1.5 ECCDA applications can include but are not limited to assessments of external corrosion on pipeline segments that: 1.1.5.1 Can be inspected using other common inspection methods (such as in-line inspection ILI or pressure test
25、ing). 1.1.5.2 Have been inspected using other inspection technologies as a method of managing future corrosion. 1.1.5.3 Have been inspected with another inspection technology as a method of establishing a reassessment interval. 1.1.6 ECCDA may detect other pipeline integrity threats such as mechanic
26、al damage, stress corrosion cracking (SCC), and microbiologically influenced corrosion (MIC). When such threats are detected, additional assessments or inspections must be performed. The pipeline operator should use appropriate methods such as ASME(1)B31.4,1ASME B31.8,2ASME B31.8S,3and API(2)11604to
27、 address risks other than external corrosion. 1.1.7 The ECCDA process has limitations, but many pipelines can be successfully assessed with ECCDA. Precautions should be taken when these techniques are applied, just as with other assessment methods. 1.1.7.1 This standard may be applied to poorly coat
28、ed or bare pipelines in accordance with the methods and procedures included in NACE SP0502,5NACE SP0207,6 and NACE Standard TM0109.7Poorly coated pipelines are usually treated as essentially bare if the cathodic current requirements to achieve protection are substantially the same as those for bare
29、pipe. (1)ASME International (ASME), Three Park Ave., New York, NY 10016-5990. (2)American Petroleum Institute (API), 1220 L St. NW, Washington, DC 20005-4070. SP0210-2010 2 NACE International 1.1.7.2 This standard may be applied only to pipelines that have been previously inspected by techniques cap
30、able of identifying and locating external corrosion. 1.1.8 For accurate and correct application of this standard, the standard shall be used in its entirety. Using or referring to only specific paragraphs or sections can lead to misinterpretation and misapplication of the recommendations and practic
31、es contained herein. 1.1.9 This standard does not designate practices for every specific situation because of the complexity of conditions to which buried piping systems are exposed. 1.1.10 The provisions of this standard should be applied under the direction of competent persons who, by reason of k
32、nowledge of the physical sciences and the principles of engineering and mathematics, acquired by education and related practical experience, are qualified to engage in the practice of corrosion control and risk assessment on buried ferrous piping systems. Such persons may be registered professional
33、engineers or persons recognized as corrosion specialists or cathodic protection (CP) specialists by organizations such as NACE or engineers or technicians with suitable levels of experience, if their professional activities include external corrosion control of buried ferrous piping systems. 1.2 Fou
34、r-Step Process 1.2.1 ECCDA requires the integration of data from multiple field examinations and from pipe surface evaluations with the pipelines physical characteristics and operating history. 1.2.2 ECCDA includes the following four steps, as shown in Figures 1(a), 1(b), and 1(c). 1.2.2.1 Preassess
35、ment. The Preassessment Step collects historic and current data to determine whether ECCDA is feasible, defines ECCDA regions, and selects indirect inspection tools. The types of data to be collected are typically available in construction records, operating and maintenance histories, alignment shee
36、ts, corrosion survey records, other aboveground inspection records, and inspection reports from prior integrity evaluations, assessments, or maintenance actions. Existing operating conditions should be verified during the preassessment step. 1.2.2.2 Indirect Inspection. The Indirect Inspection Step
37、covers aboveground inspections used to identify locations of possible corrosion and prioritize them for direct examination. A minimum of one indirect inspection tool is required. The same tool does not have to be used over the entire pipeline segment. Additional tools may be used to interpret indica
38、tions noted with the first tool. 1.2.2.3 Direct Examination. The Direct Examination Step includes analyses of indirect inspection data to select sites for excavations and pipe surface evaluations. The indications noted in the indirect inspection performed for the ECCDA should be compared to the anom
39、alies found in previous assessments. New significant indications that have moved up in the prioritization ranking are prime candidates for direct examination. Data from direct examinations are combined with prior data to identify and assess the effect of external corrosion on the pipeline. In additi
40、on, evaluation of pipeline coating performance, corrosion defect repairs, and mitigation of corrosion control deficiencies are included in this step. 1.2.2.4 Post Assessment. The Postassessment Step covers analyses of data collected from the previous three steps to assess the effectiveness of the EC
41、CDA process and confirm reassessment intervals. SP0210-2010 NACE International 3 Figure 1(a): External Corrosion Confirmatory Direct Assessment FlowchartPart 1 (Numbers refer to paragraph numbers in this standard.) External Corrosion Threat Preassessment Step Data Collection 3.2 Sufficient Data? 3.2
42、.1.1 Input on Tool Selection Table 2 Yes Input on Important Parameters Table 1 Feedback From Remaining Strength Evaluations 5.6 Define/Classify Relative Indication Severity 4.3.2 Identify and Align Indications 4.3.1From Reclassify to Reprioritize 5.9 Compare Indications 4.3.3 From Root-Cause Mitigat
43、ion 5.8 Compare with Preassessment and Prior History 4.3.4 To DIRECT EXAMINATION Perform Indirect Inspections 4.2 Resolve Discrepancies 4.3.3.1 Alternative Integrity Assessments 3.3.4 ECCDA Not Applicable Select Indirect Inspection Tools 3.4 Define ECCDA Regions 3.5 Feasibility Established? 3.3 Acce
44、ptAccept Reject Reject YesNo No No YesNo YesIndirect Inspection StepSP0210-2010 4 NACE International Figure 1(b): External Corrosion Confirmatory Direct Assessment FlowchartPart 2 (Numbers refer to paragraph numbers in this standard.) Postassessment Step Direct Examination StepTo ECDA Regions 3.5 In
45、direct Inspections 4.2 To Reclassify 4.3.2 From INDIRECT INSPECTION Section 4 Apply Alternative Integrity Assessment Methods 3.3.4 Feedback Prioritize Need for Direct Examination 5.2 Excavate and Collect Data 5.4 Measure Coating Damage and Corrosion Depth 5.5 Remaining Strength Evaluation 5.6 Root-C
46、ause Analyses 5.7 Minor Root Cause In-Process Evaluation 5.9 Classify and Prioritize Conservative? 5.9.3, 5.9.4 Address Significant Root Causes 5.7 Significant Root Cause No Yes Reassess or Reprioritize 6.3 Reassess ECCDA Feasibility 3.3 Required Number of Excavations 5.3 Corrosion Growth Rate Deter
47、mination 6.4 Define Reassessment Interval 6.5 Direct Examination for Process Validation 6.6.1 Define Effectiveness Measures 6.6.2 Continuous Improvement 7.5.1.4 Continue ECCDA Applications No Fail Fail Fail Pass Yes Feedback SP0210-2010 NACE International 5 Figure 1(c): External Corrosion Confirmato
48、ry Direct Assessment FlowchartPart 3 ECCDA -IMPERFECTION An anomaly with dimensions and characteristics that do not exceed acceptance limits DEFECT A physically examined anomaly with dimensions or characteristics that exceed acceptance limitsINSPECTION The use of a nondestructive testing technique INDICATION A signal from an in-line inspection system DATA ANALYSIS The process through which inspection indications are evaluated for classification and characterization ANOMALY An unexamined deviation from the norm in
