Understanding Pressure Piping Inspection code API 570-my self study notes

API 570 3rd edition, NOV 2009 2013- My Exam Preparation Notes

Piping Inspection Code: In-service inspection, rating, repair and alteration of piping systems.

Fion Zhang 2013/March/5

Charlie Chong/ Fion Zhang/ He Jungang / Li Xueliang

 增长业务-在职设施事故频发,  增长业务-在职设施设备的老化,  增长业务-结合RBI, RBV, QRA, RCM, 等的运用,  增长业务-结合API 57901/ASME FFS-1 合适性评估的运用,  增长业务-结合RBV作为高效认证模式,  全球资源运用-开发损伤机理/损失率,(Material Technology)的业务潜力,  技术更新-年检与维修认证管理加强- 在职/新建设备检验方法差异(间隔, 验收标准,损伤机理作为缺陷的主要原因,等),

API 570用在哪? 石油开采, 炼制和化学加工行业, 但可以使用,在切实可行的情况下, 任何管道系统


Objective 目标! 合理准确和及时评估确定可能危及管道持续安全运行的任何条件的变化业主/用户必须对任何检查结果,要求纠正措施作出回应以保证管道持续安全运行的.

合理,准确和及时评估以确定可能危及管道持续安全运行的任何条件的变化

Methodology 方法 API 570 & referred standards. This inspection code recognizes API Standard 579-1/ASME FFS-1, Fitnessfor-service适用性评估, API Recommended Practice 580, Risk-based Inspection 基于风险的检验评估

API 570 Charlie Chong/ Fion Zhang

REFERENCE PUBLICATIONS 参考规范 A. API Publications: • • • • •

API Standard 570 – Inspection, Repair, Alteration, and Rerating of InService Piping Systems API RP 571, Damage mechanisms Affecting Fixed equipment in the Refining Industry API Recommended Practice 574 – Inspection Practices for Piping System Components API RP 577, Welding Inspection and Metallurgy API Recommended Practice 578 – Material Verification Program for New and Existing Alloy Piping Systems


Copyright American Petroleum Institute










Section V, Nondestructive Examination


Section IX, Welding and brazing Qualifications


B16.5, Pipe Flanges and Flanged Fittings


B31.3, Process Piping


Content: (9 Sections with 3 Appendices.)

Content: (9 Sections with 3 Appendices.) 1. 2. 3. 4. 5. 6. 7. 8. 9.

Scope Normative References Terms & Definitions Owner/User Inspection Organizations Inspection, Examination, and Pressure Testing Practices Interval/Frequency and Extent of Inspection Inspection Data Evaluation, Analysis, and Recording Repairs, Alterations, and Re-rating of Piping Systems. Inspection of Buried Piping

Annex A (informative) Inspector Certification Annex B (informative) Requests for Interpretations Annex C (informative) Examples of Repairs

9 章节 3 附录.

Scope 范围 Normative References 标准参考 Terms & Definitions术语和定义 Owner/User Inspection Organizations 业主/用户的检验机构 Inspection, Examination, and Pressure Testing Practices 检查,检验,压力测试实践 6. Interval/Frequency and Extent of Inspection 间隔/频率和检验程度 7. Inspection Data Evaluation, Analysis, and Recording 检验数据评估,分析和记录 8. Repairs, Alterations, and Re-rating of Piping Systems. 修理,改装,管路系统的重新评级 9. Inspection of Buried Piping地管道的检验 10. Inspection of Buried Piping 埋地管道的检验 1. 2. 3. 4. 5.

9 章节 3 附录. Annex A (informative) Inspector Certification 附录A（资料性附录）督察认证 Annex B (informative) Requests for Interpretations 附录B（参考）请求诠释 Annex C (informative) Examples of Repairs 附录C（资料性附录）维修实例

Sec~0 Forward 序言


Forward 序言 A. This edition supersedes all previous editions. Each edition, revision, or addenda may be used beginning with the date of issuance. Effective 6 months after publication. 6个月后公布有效 B. During the six month lag time between issuance and affectivity, the user must specify which edition/addenda is mandatory.在公布后的前6个月过度时隔, 用户必须确认所强制性指定版/增编. C. Use of API publications API出版物使用  May be used by anyone desiring to do so.任何人  No warranties given.没有保证  Disclaims liability or responsibility for loss or damage. API 损失免责或赔偿免责声明 D. Submit revisions, reports, comments and requests for interpretations to API.请求诠释API

Sec~1 1 Scope 范围

1 Scope 范围 1.1.1 Coverage API 570 covers inspection, rating, repair, and alteration procedures for metallic and fiberglass reinforced plastic (FRP) piping systems and their associated pressure relieving devices that have been placed inservice. 覆盖范围为：  在职管线  管线检验,定级,修理和变更措施  金属和玻璃纤维管线与相关的泄压装置

1.12 The intent of this code is to specify the in-service inspection and condition-monitoring program that is needed to determine the integrity of piping. API570 规范的意图是, 具体指定 “在役检查和状况监测方案” 以确定管道的完整性

用以执行在役检查和监测方案以确保定管道的综合完整性,这方案应提供 --------------------------------------对管道运行参数的任何变化可能带来危及系统持续安全运行进行合理准确和及时的评估.业主/用户必须对任何检查结果,要求纠正措施作出回应以保证管道持续安全运行的.

Metallic 金属管线

FRP/GRP玻璃纤维

PE/PVC/PP/PS/ABS/塑膠

FRP/GRP玻璃纤维

Inservice-在职管线

New Construction/新建造

UPVC Piping

1.2.1 Included Fluid Services Except as provided in 1.2.2, API 570 applies to piping systems for process fluids, hydrocarbons, and similar flammable or toxic fluid services, such as the following: 1. Raw, intermediate, and finished petroleum products; 原材料, 半成品, 石油制成品 2. Raw, intermediate, and finished chemical products; 原材料, 半成品, 成品的化工产品; 3. Catalyst lines;催化剂线 4. Hydrogen, natural gas, fuel gas, and flare systems; 氢气, 天然气, 燃料气体和燃气排放系统

5. Sour water and hazardous waste streams above threshold limits, as defined by jurisdictional regulations; 高于阈值限制酸酸的水和有害废物流 6. Hazardous chemicals above threshold limits, as defined by jurisdictional regulations;高于阈值限制危险化学品 7. Cryogenic fluids such as: LN2, LH2, LOX, and liquid air; 低温流体的条件, 如液氮, 液氢, 液氧,液态空气. 8. High-pressure gases greater than 150 psig such as: GHe, GH2,GOX, GN2, and HPA (High-Purity Air).高压气体大于150 psig的气体

API 570 也适用于 “可选的管路系统”

1.2.2 Optional Piping Systems and Fluid Services 可选的管路系统和流体服务 The fluid services and classes of piping systems listed below are optional with regard to the requirements of API 570. a) Fluid services that are optional include the following: 1) hazardous fluid services below threshold limits, as defined by jurisdictional regulations;低于阈值限制的危险性流体服务 2) water (including fire protection systems), steam, steam-condensate, boiler feed water, and Category D fluid services, as defined in ASME B31.3. 水(包括消防系统),蒸汽,蒸汽冷凝水,锅炉补给水, ASME B31.3 “D”类流体服务 b) Other classes of piping systems that are optional are those that are exempted from the applicable process piping construction code. 那些获豁免遵守适用的工艺管道施工规范的管线

Not all piping in the facilities are covered: • Process piping that are within the scopes • Optional piping (1.2.2) • Owner/user wishes to include (1.2.2). 不是全部设施范围或场外管道被API570覆盖!

1.3 Fitness-For-Service and Risk-Based Inspection (RBI) 适用性评价 & 基于风险的检验 This inspection code recognizes Fitness-For-Service concepts for evaluating in-service damage of pressure containing components. API 579 provides detailed assessment procedures for specific types of damage that are referenced in this code. This inspection code recognizes RBI concepts for determining inspection intervals. API 580 provides guidelines for conducting a risk-based assessment. 此规范认可: • •

API 579 对特定类型的损伤, 提供了详细的评估程序 API 580 提供指导作为确定检查时间间隔

1.3 Fitness-For-Service and Risk-Based Inspection (RBI)

API 570 Recognized 认可评估方法

Fitness-for-service API Standard 579-1/ ASME FFS-1,

RBI-API 580/581

API 570 Recognized 认可评估方法 RBI 基于风险评估的设备检验技术

API 580/581 A risk assessment and risk management process that is focused on inspection planning for piping systems for loss of containment in processing facilities, which considers both:  the probability of failure and  consequence of failure due to material deterioration.

API 570 Recognized 认可评估方法 Fitness-for-service 运行适应性(FFS) 安全评定

API Standard 579-1/ ASME FFS-1. This inspection code recognizes fitness-ForService concepts for evaluating in-service damage of pressure containing components. API 579 provides detailed assessment procedures for specific types of damage that are referenced in this code.

API 570 Recognized 认可评估方法 FFS/RBI - 处理方法优先于 API570 对检验范围与方法的要求

Take/has priority over API570 requirements on extents and intervals of inspection (with limitation see 5.2.4) API Standard 579-1/ASME FFS-1.对特定类型的损害提供详细的评估程序, 优先于API570要求. 5.2.4 The maximum intervals between RBI assessments are outlined in 6.3.2, Table 2.

Fitness-for-service 运行适应性(FFS) 安全评定API Standard 579-1/ASME FFS-1. Assessment requires the use of a future corrosion allowance  Assessment of General Metal Loss—API 579-1/ASME FFS-1, Section 4.  Assessment of Local Metal Loss—API 579-1/ASME FFS-1, Section 5.  Assessment of Pitting Corrosion—API 579-1/ASME FFS-1, Section 6. In some cases will require the use of a future corrosion Allowance  Assessment of blisters and laminations-API 579-1/ASME FFS-1, Section 7 Assessment not requires the use of a future corrosion allowance  Assessment of weld misalignment and shell distortions- API 579-1/ASME FFS1, Section 8.  Assessment of crack-like flaws- API 579-1/ASME FFS-1, Section 9.  Assessment of effects of fire damage-API 579-1/ASME FFS-1, Section 11.

Sec~2 2 Normative References

2 Normative References 1 ASME International, 3 Park Avenue, New York, New York 10016-5990, www.asme.org. 2 American Society for Nondestructive Testing, 1711 Arlingate Lane, P.O. Box 28518, Columbus, Ohio 43228, www.asnt.org. 3 ASTM International, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania 19428, www.astm.org. 4 Materials Technology Institute, 1215 Fern Ridge Parkway, Suite 206, St. Louis, Missouri 63141-4405, www.mti-link.org. 5 NACE International (formerly the National Association of Corrosion Engineers), 1440 South Creek Drive, Houston, Texas 77218-8340, www.nace.org. 6 National Fire Protection Association, 1 Batterymarch Park, Quincy, Massachusetts 02169-7471, www.nfpa.org.

Sec~3 3 Terms, Definitions, Acronyms, and Abbreviations

3 Terms, Definitions, Acronyms, and Abbreviations

3.1.19 design temperature of a piping system component The temperature at which, under the coincident pressure, the greatest thickness or highest component rating is required. It is the same as the design temperature defined in ASME B31.3 and other code sections and is subject to the same rules relating to allowances for variations of pressure or temperature or both. Quality control functions performed by examiners (or inspectors) as defined elsewhere in this document.

The API 570 candidate must know all terms and definitions. Some of the terms that have been on the test, include: 3.1 Alterations 3.4 Authorized Inspection Agency 3.6 Auxiliary Piping 3.9 Deadlegs 3.12 Examiner 3.13 Imperfections 3.16 Injection Point 3.31 Piping Circuit 3.33 Piping System 3.34 Primary Process Piping 3.37 Repair 3.38 Repair Organization 3.41 SBP 3.46 Test Point 3.47 TML

Sec~4 4 Owner/User Inspection Organization

4 Owner/User Inspection Organization 用户组织机构

4 Owner/User Inspection Organization

4.1 General 4.2 Authorized Piping Inspector Qualification and Certification 4.3 Responsibilities 4.3.1 Owner/User Organization 4.3.2 Piping Engineer 4.3.3 Repair Organization 4.3.4 Authorized Piping Inspector 4.3.5 Examiners 4.3.6 Other Personnel

资质,分工与职责业主/用户机构: 5大类人员分工 1. Piping Engineer / Corrosion Specialist 管道工程师/腐蚀专家 2. Repair organization 维修单位 3. API Authorized Inspector 授权检验师 4. Examiners 协助检验员 5. Other Personnel 其他人员

Charlie Chong/ Fion Zhang

4.1 General 大致与责任业主/用户机构责任 1. 管道系统行使控制的管道系统的检查程序,检查频率, 维护和授权的检验机构的功能. 2. 对授权检验机构执行API 570的规定的功能负责. 3. 业主/用户的检验机构也应控制活动有关的评级,维修和改建管道系统. 4. 确定与建立关键工艺参数：应建立如果控制不当,可能会影响设备的完整性的关键工艺参数.实施例的工艺参数有: 温度,压力,流体速度,pH值,流速, 化学或注水率,腐蚀性成分,化学成分等.

Integrity operating envelopes 工艺参数业主/用户机构责任: 确定与建立关键工艺参数：应建立如果控制不当,可能会影响设备的完整性的关键工艺参数. 实施例的工艺参数有: 温度，压力，流体速度，pH值，流速，化学或注水率，腐蚀性成分，化学成分等


4.2 Authorized Piping Inspector Qualification and Certification Authorized piping inspectors shall have education and experience in accordance with Annex A of this inspection code. Authorized piping inspectors shall be certified in accordance with the provisions of Annex A. Whenever the term inspector is used in this code, it refers to an authorized piping inspector.

授权管道检查员应附录A的规定认证

Education and Experience. 教育和经验 1. BS in engineering or technology plus one year of experience in the design, construction, repair, operation, or inspection of piping systems or supervision of piping inspection. 2. 2-year certificate or degree in engineering or technology plus 2 years of experience in the design, construction, repair, operation, or inspection of piping systems or supervision of inspection of piping systems. 3. The equivalent of a high school education plus 3 years of experience in the design, construction, repair, operation, or inspection of piping systems or supervision of inspection of piping systems. 4. A minimum of five years of experience in the design, construction, repair, inspection or operation of piping systems, or supervision of inspection.

Education and Experience. 教育和经验


4.3 Responsibilities职责 4.3.1 Owner/User Organization业主/用户组织 4.3.1.1 Systems and Procedures 制度和程序

An owner/user organization is responsible for developing, documenting, implementing, executing, and assessing piping inspection systems and inspection procedures that will meet the requirements of this inspection code. These systems and procedures will be contained in a quality assurance inspection/repair management system and shall include: 业主/用户组织负责开发，记录，实施，执行和评估管道检测系统和检验程序以满足此规范.这些系统和程序将包含在质量保证检查/维修管理系统，并应包括。。。。。

业主/用户机构负责开发,记录,实施,执行和评估,管道检查系统和检查符合API570要求的程序

4.3.1.1 Systems and Procedures 制度和程序包括： 1. organization and reporting structure for inspection personnel; 检验人员的组织结构和报告 2. documenting and maintaining inspection and quality assurance procedures; 记录和维护检验和质量保证程序 3. documenting and reporting inspection and test results; 检验和试验结果的记录和报告 4. developing and documenting inspection plans; 检查计划的制定和记录 5. developing and documenting risk-based assessments; 开发基于风险的评估和记录 6. developing and documenting the appropriate inspection intervals; 开发和记录相应的检验间隔

7. corrective action for inspection and test results; 检验和试验结果的纠正措施 8. internal auditing for compliance with the quality assurance inspection manual;内部审计的质量保证检查手册 9. review and approval of drawings, design calculations, and specifications for repairs, alterations, and re-ratings; 审查和批准图纸，设计计算和规格,修理,改装,并重新评级 10. ensuring that all jurisdictional requirements for piping inspection, repairs, alterations, and re-rating are continuously met;确保满足所有司法管辖区的管道检测，维修，改装，重新评级的要求。 11. reporting to the authorized piping inspector any process changes that could affect piping integrity; 报告任何过程的变化，可能影响管道完整性的授权管道督察

12. training requirements for inspection personnel regarding inspection tools, techniques, and technical knowledge base; 检查人员对检查的工具，技术和技术知识基础的培训要求。

13.controls necessary so that only qualified welders and procedures are used for all repairs and alterations; 必要控制合格的焊工和程序被用于所有的维修和改装 14. controls necessary so that only qualified NDE personnel and procedures are utilized;必要控制合格的无损检测人员和程序 15. controls necessary so that only materials conforming to the applicable section of the ASME Code are utilized for repairs and alterations; 必要控制符合ASME规范的适用部分的材料用于检修和改建

16.controls necessary so that all inspection measurement and test equipment are properly maintained and calibrated; 检验测量和测试设备的正确维护和校准 17. controls necessary so that the work of contract inspection or repair organizations meet the same inspection requirements as the owner/user organization; 合同检查或维修机构的工作,满足业主/用户的检验要求. 18. internal auditing requirements for the quality control system for pressure-relieving devices. 泄压装置的质量控制系统的内部审计要求

4.3.1.2 MOC 变革管理 The owner/user is also responsible for implementing an effective MOC process that will review and control changes to the process and to the hardware. An effective MOC process is vital to the success of any piping integrity management program in order that the inspection group will be able to anticipate changes in corrosion or other deterioration variables and alter the inspection plan to account for those changes. The MOC process shall include the appropriate materials/corrosion experience and expertise in order to effectively forecast what changes might affect piping integrity. The inspection group shall be involved in the approval process for changes that may affect piping integrity. Changes to the hardware and the process shall be included in the MOC process to ensure its effectiveness. 业主/用户也负责实施有效 “MOC管理变革” MOC过程应包括合适的材料/腐蚀的经验和专业知识，以便有效地预测什么样的变化,可能会影响管道完整性 - 检查组应参与MOC审批.

4.3.1.2 MOC变革管理 Changes to the hardware and the process shall be included in the MOC process to ensure its effectiveness. 变革管理: 应包括 (1) 硬件 (改造, 更新, 重新设计, 注射点更改,更换位置,等) 和 (2) 工艺程序的变化 (例如:温度,压力,溶液,化学成分,含氧量,污染物,缓解剂,等).以确保其有效性

管道工程师修复组织

4.3.2 Piping Engineer The piping engineer is responsible to the owner/user for activities involving design, engineering review, rating, analysis, or evaluation of piping systems covered by API 570. 管道工程师业主/用户负责, API 570所涵盖的职责: 涉及设计,工程审查,评级, 分析,评价管道系统. 4.3.3 Repair Organization All repairs and alterations shall be performed by a repair organization. The repair organization shall be responsible to the owner/user and shall provide the materials, equipment, quality control, and workmanship necessary to maintain and repair the piping systems in accordance with the requirements of API 570. 修复组织按照API 570的要求,维护和修理管道系统

4.3.4 Authorized Piping Inspector When inspections, repairs, or alterations are being conducted on piping systems, an authorized piping inspector shall be responsible to the owner/user for:  determining that the requirements of API 570 on inspection, examination, quality assurance and testing are met. 检验符合规范要求  The inspector shall be directly involved in the inspection activities which in most cases will require field activities to ensure that procedures are followed. 应在现场监督工作  The inspector is also responsible for extending the scope of the inspection (with appropriate consultation with engineers/specialists), where justified depending upon the findings of the inspection. 在适当的咨询工程师/专家下,依照检验结果,增加检验项/范围.  Where non-conformances are discovered, the inspector is responsible for notifying the owner-user in a timely manner and making appropriate repair or other mitigative recommendations. 当不合格项被发现时能及时的通知业主和提供合适的返修/缓解建议.

现场监督工作 field activities

4.3.5 Examiners 测试员

4.3.5.1 The examiner shall perform the NDE in accordance with job requirements. 4.3.5.2 The examiner is not required to be certified in accordance with Annex A and does not need to be an employee of the owner/user. The examiner shall be trained and competent in the NDE procedures being used and may be required by the owner/user to prove competency by holding certifications in those procedures. Examples of other certifications that may be required include ASNT SNT-TC-1A, ASNT CP-189, and AWS QC1. 4.3.5.3 The examiner’s employer shall maintain certification records of the examiners employed, including dates and results of personnel qualifications. These records shall be available to the inspector. 检验员为合格目视与无损探伤人员. 无损探伤检验资格如ASNT SNT-TC-1A, ASNT CP-189, 焊接检验资格 AWS QC1 或等同. 检验员必须充分掌握应用程序所需要的知识. 检验员不需要拥有授权管道检查员资格证.

4.3.6 Other Personnel 其他人员 Operating, maintenance, engineering or other personnel who have special knowledge or expertise related to particular piping systems shall be responsible for timely notification to the inspector or engineer of issues that may affect piping integrity such as the following: 及时的通知检验员或工程师任何影响管线完整性的发现 a) any action that requires MOC; 任何需要变革管理的状况 b) operations outside defined integrity operating envelopes; IOE外的操作 c) changes in source of feedstock and other process fluids; 原料或溶液的变化. d) piping failures, repair actions conducted and failure analysis reports; 管线修护或任何修护/更改项 e) cleaning and decontamination methods used or other maintenance procedures that could affect piping and equipment integrity; 清洗/其污方法的变动(至于影响管道机械完整性的更改)

a) reports of experiences that other plants have had with similar service piping and associated equipment failures; 在其他厂区其他相似的故障的信息分享 f) any unusual conditions that may develop (e.g. noises, leaks, vibration, etc.). 非正常的操作发现(声音,震动,泄漏,等)

其他人员: 那些有特殊知识或相关操作专业知识,维修,工程人员或其他人员.

其他人员: 那些有特殊知识或相关操作专业知识,维修,工程人员或其他人员.

其他人员: 那些有特殊知识或相关操作专业知识,维修, 工程人员或其他人员

Sec~5 5 Inspection, Examination, and Pressure Testing Practices

5 Inspection, Examination, and Pressure Testing Practices 检查,检验,压力测试实践

5 Inspection, Examination, and Pressure Testing Practices 检查,检查,和压力测试实践 5.1 Inspection Plans检查计划 5.2 Risk-Based Inspection基于风险的检验 5.3 Preparation for Inspection检验准备 5.4 Inspection for Types and Locations of Damage Modes of Deterioration and Failure 退化和失效破坏模式的位置与类型检查 5.5 General Types of Inspection and Surveillance 通用型检验与检测 5.6 CMLs 腐蚀监视点 5.7 Condition Monitoring Methods 状态监测方法 5.8 Pressure Testing of Piping Systems-General 管道系统压力测试-大概 5.9 Material Verification and Traceability 材料的验证和跟踪 5.10 Inspection of Valves 阀门检验 5.11 In-service Inspection of Welds 在职焊缝检验 5.12 Inspection of Flanged Joints 法兰接头检验 5.13 Inspection Organization Audits 检验组织考核

5.1 Inspection Plans 检验计划

5.1.1 Development of an Inspection Plan 制定检验计划 5.1.1.1 An inspection plan shall be established for all piping systems within the scope of this code. The inspection plan shall be developed by the inspector and/or engineer. A corrosion specialist should be consulted as needed to clarify potential damage mechanisms and specific locations where degradation may occur. A corrosion specialist should be consulted when developing the inspection plan for piping systems that operate at elevated temperatures [above 750oF (400oC)] and piping systems that operate below the ductile-to-brittle transition temperature.  授权管道检查员/或工程师要对所有管道系统检查应制定检查计划.  在制定该计划时应征询腐蚀专家关于潜在损伤机理与可能发生的所在处.  制定高温管道系统 750°C (400°C)和管道运行温度低于母材的韧性 - 脆性转变温度时该计划时应征询腐蚀专家的意见.

New Fabrication 新建检验

 小编-缺陷为加工(焊接,锻造,铸造, 热处理,冷加工,等)或原材料造成,  小编-接受标准按照法定允许建造规范相关章节.  小编-结果:合格/不合格(返修/报废)  小编-缓解后续:重检(一般上规范要求必须同样检验/探伤方法)

In-Service 在职检验

 在制定该计划时应征询腐蚀专家关于潜在损伤机理与可能发生的所在处,  制定高温管道系统 750°C (400°C)和管道运行温度低于母材的韧性 - 脆性转变温度时该计划时应征询腐蚀专家的意见,  小编-结果:识别损伤机理(多项),启发因素, 计算恶化率,缓解(多样化)与后续监测,  小编-缓解后续:重检(检验方法更新,等)重估 (需要多专业参与)

A corrosion specialist should be consulted if the service temperature operate above 750oF (400oC) 编制高温管线ITP应当咨询询腐蚀专家意见. 高温管道系统 750oF (400oC)

高温管道系统 750oF (400oC)

A corrosion specialist should be consulted 应征询腐蚀专家

Piping systems that operate at elevated temperatures may suffer; 在升高的温度下操作的管道系统可能造成的破坏机理;

Graphitization

Hydrogen Blistering

graphitization

Hydrogen Blistering

Creep / Stress Rupture

Graphitization 石墨化

Piping systems that operate below the ductile-to-brittle transition temperature 管道系统的韧性 - 脆性转变温度以下



5.1.1.2 The inspection plan is developed from the analysis of several sources of data. Piping systems shall be evaluated based on (1) present or (2) possible types of damage mechanisms. The methods and the extent of NDE shall be evaluated to assure they can adequately identify the damage mechanism and the severity of damage. Examinations shall be scheduled at intervals that consider the: 无损探伤检测间隔设定的考虑因素有; a) type of damage, 损伤类别 b) rate of damage progression, 损伤扩展率 c) tolerance of the equipment to the type of damage, 设备对损伤机理的容忍性 d) capability of the NDE method to identify the damage, 可探性 e) maximum intervals as defined in codes and standards, and 法定规范最大间隔限制 f) extent of examination. 覆盖范围小编: 损伤预测位置.

Additionally, the use of RBI (see 5.2) is recommended when developing the required inspection plans, and to review recent operating history and MOC records that may impact inspection plans. 基于风险分析探伤方法被此规范推荐. 变革管理所提供的信息也会影响ITP的编制内容.

变革管理所提供的信息也会影响ITP的编制内容

ITP 开发时所需的检查计划时应当考虑; 1. 建议运用基于RBI 风险的检验方法 2. 近期的操作生产历史记录 3. MOC 建设/改造(历史)记录

5.1.1.3 The inspection plan should be developed using the most appropriate sources of information including those references listed in Section 2. Inspection plans shall be reviewed and amended as needed when variables that may impact damage mechanisms and/or deterioration rates are identified. See API 574 for more information on the development of inspection plans. 当损坏机理或损坏扩展率(腐蚀率)有所变化/变量时-检查计划应当进行重新审核与更新/修改

授权管道检查员/或工程师管理下：检查计划应是个动态文件！制定/保管人是: 业主/用户 (1) 授权管道检查员或 (2)工程师

5.1.2 Minimum Contents of an Inspection Plan 检验计划的内容最低要求 The inspection plan shall contain the inspection tasks and schedule required to monitor identified damage mechanisms and assure the pressure integrity of the piping systems. 检验计划应包含 ”检查项” 和 “时间表” 以 (1) 识别/ (2) 监控损伤机理,并确保压力管道系统的完整性.

The plan should: 该计划应包含以下最低内容 a) define the types of inspection needed, e.g. internal, external, onstream (nonintrusive);检查型类(例如内部/外部/在线 - 非侵入/侵入). b) identify the next inspection date for each inspection type; 确定每项下次检验日期 c) describe the inspection methods and NDE techniques; 描述的检验方法和无损检测技术 d) describe the extent and locations of inspection and NDE at CMLs; 描述的检验范围和检查/无损检测位置 CML. e) describe the surface cleaning requirements needed for inspection and examinations for each type of inspection; 描述的表面的清洗要求小编: In-service 在职, on-stream 在线(带压)

f. describe the requirements of any needed pressure test (e.g. type of test, test pressure, test temperature, and duration); 描述压力测试(如果必要)要求(例如:方法,压力,试温,保压时间) g. describe any required repairs if known or previously planned before the upcoming inspection. 先前,计划维修项. Generic inspection plans based on industry standards and practices may be used as a starting point in developing specific inspection plans. The inspection plan may or may not exist in a single document, however the contents of the plan should be readily accessible from inspection data systems. 作为起点: 通用的行业标准检验计划和常规惯例方法,可以被用来启动新的检查起点,以便定制后续更加详细具体检验要求.

5.1.3 Additional Contents of an Inspection Plan 检验计划的其他内容 Inspection plans may also contain other details to assist in understanding the rationale for the plan and in executing the plan. Some of these details may include: 1. describing the types of damage anticipated or experienced in the piping systems; 描述,管道系统预测或经历过的损伤机理. 2. defining the location of the expected damage; 预测的损坏的位置 3. defining any special access, and preparation needed. 任何特殊的空间要求和必须前期检验准备.

特殊的空间要求和必须前期检验准备




5.2 RBI 基于风险评估的设备检验技术

5.2 RBI 基于风险评估的设备检验技术 RBI can be used to determine inspection intervals and the type and extent of future inspection/examinations. When the owner/user chooses to conduct an RBI assessment it shall include a systematic evaluation of both the probability and the associated consequence of failure, in accordance with API 580. API 581 details an RBI methodology that has all of the key elements defined in API 580. RBI (API 580/581) 做为系统性评价 - 失效概率和故障后果,可以用来确定:  检查的时间间隔和  未来的检验/检查的类型和程度。

Identifying and evaluating potential damage mechanisms, current equipment condition and the effectiveness of the past inspections are important steps in assessing the probability of piping failure. Identifying and evaluating the process fluids, potential injuries, environmental damage, equipment damage and equipment downtime are important steps in assessing the consequence of piping failure. Identifying integrity operating envelopes for key process variables is an important adjunct to RBI (see 4.1). 基于风险分析检验,两个主要元素为: 失效概率与失效后果. 影响这两个元素的有; 失效概率: 损伤机理,当前设备状况,过去检验方法效率,等. 故障后果: 工艺液体,安全,环境破坏,设备损坏,设备停工期,等. 识别操作完整性窗口的主要参数,是RBI方法的重要辅助数据.

5.2.1 Probability Assessment 概率评估 The probability assessment shall be in accordance with API 580 and shall be based on all forms of damage that could reasonably be expected to affect equipment in any particular service. Examples of those damage mechanisms are shown in Table 1. Additionally, the effectiveness of the inspection practices, tools, and techniques used for finding the potential damage mechanisms shall be evaluated. Other factors that should be considered in a probability assessment include: 表-1,列出可能存在的损伤机理. 检验方法的效率对损伤机理的可探性需要评估,其他考虑点有; a) appropriateness of the materials of construction; 选材是否正确 b) equipment design conditions, relative to operating conditions; 设计是否满足操作要求 c) appropriateness of the design codes and standards utilized; 设计标准,规范是否适当 d) effectiveness of corrosion monitoring programs; 腐蚀检测计划的效应.

e) the quality of maintenance and inspection quality assurance/quality control programs; 维护/质量保证/质量控制程序,的有效执行与可信度 f) both the pressure retaining and structural requirements; (受压/结构,要求)? g) operating conditions both past and projected. 操作情况(历史/现在/预期) Piping failure data will be important information for this assessment when conducting a probability assessment. 管线失效数据对概率评估起着重要帮助.

5.2.2 Consequence Assessment 后果评估 The consequence of a release is dependent on type and amount of process fluid contained in the equipment. The consequence assessment shall be in accordance with API 580 and shall consider the potential incidents that may occur as a result of fluid release, the size of a potential release, and the type of a potential release (includes explosion, fire, or toxic exposure.) The assessment should also determine the potential outcomes that may occur as a result of fluid release or equipment damage, which may include: health effects, environmental impact, additional equipment damage, and process downtime or slowdown. 流体释放的破坏影响有赖于设备中的工艺流体的类型(包括爆炸, 火灾, 或接触有毒物)和数量.评估还应确定设备损坏，其中可能包括：对健康的影响, 环境的影响, 额外的设备损坏, 生产停工或放缓

RBI 基于风险评估的设备检验技术概率评估后果评估应按照API 580

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5.2.3 Documentation 文件档案风险评估的设备检验技术产生文件必须按照 API 580 归档保存. 风险评估的设备检验技术产生定论能更好地定义了以下工作: a. the most appropriate inspection and NDE methods, tools, and techniques; 最适当的检查和无损检测方法,工具,和技术, b. the extent of NDE (e.g. percentage of equipment to examine); 无损的程度(如设备检查的百分比), c. the interval for internal (where applicable), external, and on-stream inspections;检验时间间隔 - 内部(如适用/外部和外部在职.

d. the need for pressure testing after damage has occurred or after repairs/alterations have been completed; 损坏/维修/改装后进行压力测试的需要性. e. the prevention and mitigation steps to reduce the probability and consequence of equipment failure. (e.g. repairs, process changes, inhibitors, etc.). 确定预防和缓解措施,以减少设备故障的概率和后果(如维修,工艺的变化, 抑制剂等)

API Standard 579-1/ASME FFS-1, Fitness-for-service 适用性评估, API RP 580, Risk-based Inspection 基于风险的检验评估

法定要求 Regulatory

API 570 & referred standards.

5.2.4 Frequency of RBI Assessments 评估频率与评估应更新 When RBI assessments are used to set equipment inspection intervals, the assessment shall be updated after each equipment inspection as defined in API 580. The RBI assessment shall also be updated each time process or hardware changes are made or after any event occurs that could significantly affect damage rates or damage mechanisms. The maximum intervals between RBI assessments are outlined in 6.3.2, Table 2. RBI 评估在以下情况下应更新:   

每个设备依照API580要求检查后每次工艺流程或硬件的变化任何可以显着影响损伤率或损坏机制事件发生时

最大间隔参考表格-2.

RBI 评估最大间隔不能大于(1) API570规定检验间隔或 (2)按照腐蚀率计算得到的- (半衰期)检验间隔.

Q-Risk based inspections include which of the following: a) b) c) d)

Likelihood assessment Consequence analysis Operating and inspection histories All of the above

Q- An RBI assessment can be used to alter the inspection strategy provided: a) b) c) d)

The degradation methods are identified The RBI is fully documented. A third party conducts the RBI Both A and B above

5.3 Preparation for Inspection 检查前的准备工作

5.3.1 General 大纲编制管道系统的检查和维护活动时注意安全事项, 这包括: 接触有害液体, 能源和物理危害. 并在适用的情况下,应遵循安全条例[例如：美国职业安全与健康管理局(OSHA)和业主/用户的安全程序. 管道检验的安全方面的更多信息，请参见API Recommended Practice 574, Inspection Practices for Piping System Components

5.3.2 Inspection Equipment Preparation 检测设备准备 5.3.3 Communication 沟通 5.3.4 Piping Entry 管道进入内部防爆/安全必须符合国家与业主安全要求! 1. 2. 3. 4. 5. 6.

在筹备管道系统的检查,应佩戴个人防护装备一切工具检验设备应检查是否损坏和/或在使用前可操作性. 无损探伤设备和修复组织的设备须符合电气设备的安全要求. 其他工具应合适使用并通过安全检查后方可使用. 在进入管道系统须取得负责的工作人员许可. 工作许可制度应当严格遵守.

大管入管(密闭空间)检验 1. 2. 3. 4. 5.

管内外人员有效通讯保障. 确保持续安全的通风和流体隔离预防措施确保安全出口/紧急疏散. 相关活动应明确的传达给所有参与人员和附近人员. 配备防护设备保护个人免受在管道系统中可能存在的具体危害

5.3.5 Records Review 检验前期记录检查 Before performing any of the required inspections, inspectors shall familiarize themselves with prior history of the piping system for which they are responsible. In particular, they should review the piping system’s prior inspection results, prior repairs, current inspection plan, and/or other similar service inspections. Additionally it is advisable to ascertain recent operating history that may affect the inspection plan. The types of damage and failure modes experienced by piping systems are provided in API 571 [5] and API 579-1/ASME FFS-1. 在执行任何所需的检查, 检查人员应当熟悉管道系统前期状况:     

历史维修记录当前的检查计划其他类似的服务的检查(小编:其他管线检验信息作为参考) 可能影响检验计划的任何操作信息 API 571和API 579-1/ASME FFS-1评估得到的损伤和失效模式信息.

5.4 Inspection for Types and Locations of Damage Modes of Deterioration and Failure 损坏/失效模式的类型与检查位置

5.4.1.1 管道系统很容易受到损害的各类几个损坏机理.典型损害类型和机理示于表-1 5.4.1.2 设备损坏,存在的或潜在的损伤机理, 是取决于其; (1)构造材料, (2)设计, (3)建造和(4) 运行条件. 检验员应当对上述情况以及潜在缺陷/损伤机理的起因和特征有所认识(熟悉).

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API 571 Program Information API 571 Certification program tests individual’s knowledge and expertise in the field of Corrosion and Materials. The examination questions are derived from API RP 571 - Damage Mechanisms Affecting Fixed Equipment in the Refining Industry. API welcomes highly specialized inspectors, corrosion engineers, chemical engineers and other professionals across the entire petrochemical industry to obtain this certification as a validation of their profound knowledge of corrosion processes. Body of Knowledge for this examination consists of the entire RP 571 with the exception of the following sections: 1.1, 3.1, 4.1, 5.2. Completely optional, yet adding significant value to your professional credentials – it will show your employers and clients that you have obtained a high level of proficiency and understanding in this important field.

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5.4.2 Areas of Deterioration for Piping Systems 管道系统关注点以下容易受到损伤特定类型和地区,管路系统检查关注点. a. b. c. d. e. f. g. h.

injection points and mix points注射点和混合点 Dead-leg, 分支盲点 CUI, 保温层内部腐蚀 soil air interfaces, 土壤空气接口 service specific and localized corrosion, 局部腐蚀 erosion and corrosion/erosion, 冲蚀和腐蚀/冲蚀 environmental cracking, 环境开裂 contact point corrosion. 缝隙(接触点)腐蚀

i) fatigue cracking,疲劳开裂 j) creep cracking,蠕变开裂 k) brittle fracture,脆性断裂 l) freeze damage,冻害 m) contact point corrosion.缝隙腐蚀更详细的信息，请参阅API 571和API 574

5.5 General Types of Inspection and Surveillance 一般类型检查和监视

5.5 General Types of Inspection and Surveillance 根据不同管道系统类型/情况,需要不同的检验和监督.这包括以下内容: a. b. c. d. e. f. g. h.

内部目视检查外部在线检查测厚检查外部目视检验保温层下腐蚀检验管道振动检查补充(附加)检查注射点检

请参阅第6节检查的间隔/频率和程度. 在检验/视察过程中发现的缺陷必须按照第7章要求定型(类别),定量与评估.

5.5.1 Internal Visual Inspection 内部目视检查大直径的传输线,导管,催化剂线,或其他大直径管道系统一般上不需要特别工具, 当管道太小无法进入时可以考虑远程可视化检测技术. 其他内部目视的情况有:断开管道法兰, 在有必要时可以卸下管道沿其中心线分割两半进行目视/探伤检验.

Internal Visual Inspection 内部目视检查

5.5.2 On-stream Inspection 在职管线检验所有在职管线检查工作应当由API 授权检验员批准.选择检验技术应考虑选用方法是否能从外部表面准确的确定 (1) 特定损伤机理与 (2) 损伤程度. 选用检查方法是也必须考虑管线在职管线的工艺流程状态: 温度, (小编: 保温层, 震动等). API 574 提供更多的详细信息. API Recommended Practice 574, Inspection Practices for Piping System Components

5.5.3 Thickness Measurement Inspection 厚度测量检验管道组件厚度测量是获取验证当前壁厚,这个数据被用来计算管路系统的 (1) 腐蚀速率和(2) 剩余寿命.测量方法是按照程序执行.操作人员必须经过培训合格.一般上厚度检测是在,在职管线上执行.当不寻常的厚度变化被检查(加速腐蚀速率), 应当咨询腐蚀专家的意见与启动相应的对策方法. 包括: 额外的厚度读数, UT扫描可疑区域,腐蚀/过程监控,修改管道检查计划等.

当不寻常的厚度变化被检查(加速腐蚀速率), 应当咨询腐蚀专家的意见与启动相应的对策方法. 包括: 额外的厚度读数, UT扫描可疑区域,腐蚀/过程监控,修改管道检查计划等.

当不寻常的厚度变化被检查(加速腐蚀速率), 应当咨询腐蚀专家的意见与启动相应的对策方法. 包括: 额外的厚度读数, UT扫描可疑区域,腐蚀/过程监控, 修改管道检查计划等.

5.5.4 External Visual Inspection 外部目测检查执行外部目测检查以确定管道的外侧,保温层, 涂层,以及相关联配件,并检查泄漏, 管线偏心/移位,振动的迹象.

泄漏

泄漏

泄漏

泄漏

泄漏

泄漏

当注意到腐蚀产物堆积在管道支撑的接触面时,可能有必要解除支持提升管道协助下侧面检查. 如是在职管线, 应格外小心并咨询工程师讨论检测方案. 除了提升管道目视方法, 可以考虑使用适当的无损检测方法 (如 EMAT Lamb wave UT – 水平波方法等) 兰姆波探伤:

泄漏

泄漏

在执行外观目视时应当注意未经批准的现场管道修改. 也应该留意不合规格的法兰,软管,阀门.易拆件如螺栓/法兰组装管件特别需要关注以防非达标的材料与耐压等级用在管道上.合格的操作或维护人员也可以协助进行外部检查. 在这种情况下,应按照 API 570通过适当的合格训练培训.

5.5.5 External Inspection of Buried Equipment 填埋设备外部检查填埋设备外部检查间隔应基于腐蚀速率获得的信息 a. b. c. d. e. f. g.

维护时类似材料连接管道同样材料填埋腐蚀试验券从实际别处代表性的部分的配管在类似情况下埋地管道(土质,土壤电阻,化学成分等) 永久性填埋安装厚度监控设备远程内窥镜目视信息阴极保护调查

5.5.6 CUI Inspection 保温层腐蚀检验在 API 574 提示对CUI 保温层腐蚀敏感地区或温度范围应考虑进行CUI 检验. 在外观目视时也该同时进行CUI外观检验. 一般上如果保温层的状况优良, 保温层的去除是不必要的. 值得注意的是 CUI可能很隐伏,往往相当隐袭的往往可能会发生在似乎不大可能区域中. 以下情况作为保温层去除考虑项: a. 特定的管道或类似的管道系统的历史特征 b. 目视检验发现与结果 c. 液体泄漏(如污渍或蒸气) d. 管线间歇性的运行 e. 外表涂层的状况 f. 保温层潮湿痕迹 g. 保温层材料抗潮性.

5.5.7 Vibrating Piping and Line Movement Surveillance 管道振动和移位操作人员应对不寻常的管道振动或摇摆向工程师或检查人员反馈. 在管道系统抑制振动处(如管托,固定锚, 导向,支柱, 减震器,支架等) 除了外观目视, 周期性的磁粉/着色(MT/PT) 无损探伤检测疲劳开裂. 在检测管道振动和移位损坏时, 分支连接应受到特别的关注, 特别是连接到振动管的无支撑的小口径管道.

5.5.8 Supplemental Inspection 补充检查适当或必要,可安排其他检查: 如射线与热成像检查 thermography 能检查管道内部结垢或内部堵塞. 热成像检查能有效的探测出管道耐火材料衬系统出现的热点.

热成像检查能有效的探测出管道耐火材料衬系统出现的热点

Acoustic emission, acoustic leak detection, and thermography can be used for remote leak detection and surveillance.声发射检测, 声发射泄漏检测, 热成像检测可用于远程泄漏的检测和监视

Areas susceptible to localized erosion or erosion-corrosion should be inspected using visual inspection internally if possible or by using radiography. Scanning of the areas with UT is also a good technique and should be used if the line is larger than NPS 12.易受局部侵蚀或冲刷腐蚀的区域应使用目视检查内部如果可能的

话或用X光检查. 大于NPS 12 的管道UT是一个很好的技术

A New Method for Radiographic Image Evaluation for Pipe Wall Thickness Measurement J. Belenkij, C. Müller (Nockemann), M. Scharmach Bundesanstalt für Materialforschung und Prüfung (BAM), Unter den Eichen 87, 12205, Berlin, Germany. V. Vengrinovich, Institute of Applied Physics, Akademicheskaya str.16, 220072, Minsk, Belarus.

5.5.9 Injection Point Inspection 注入点检查 Injection points are sometimes subject to accelerated or localized corrosion from normal or abnormal operating conditions. Those that are may be treated as separate inspection circuits, and these areas need to be inspected thoroughly on a regular schedule. 正常或非正常工作条件下注射点有时受到

加速或局部腐蚀.这些区域需要定期彻底检查

The selection of thickness measurement locations (TML) within injection point circuits subject to localized corrosion should be in accordance with the following guidelines: a. establish TML on appropriate fittings within the injection point circuit,在注入点回路中在受影响的管路配件作为TML测厚点. b. establish TML on the pipe wall at the location of expected pipe wall impingement of injected fluid, 预期注入液碰壁位置处作为TML测厚点 c. establish TML at intermediate locations along the longer straight piping within the injection point circuit may be required, 可能需要沿较长的直线管道的中间位置(注入点回路范围内),作为TML测厚点 d. establish TML at both the upstream and downstream limits of the injection point circuit. 在注入点回路上游和下游的界限点上放置TML测厚仪.

The preferred methods of inspecting injection points are radiography and/or UT, as appropriate, to establish the minimum thickness at each TML. Close grid ultrasonic measurements or scanning may be used, as long as temperatures are appropriate.

推荐TML 检测方法：  推荐方法-(1) 射线, (2) 超声检测.  网格式精细超声测厚也能用上(表面温度允许下).  对于某些应用情况, 也可拆卸管线做内部目视辅助 TML检测.

TML-using radioscopy放射线透视厚度检测

Close grid UT nic measurements or scanning may be used, as long as temperatures are appropriate.

网格式精细超声测厚能被用上.(表面温度允许下).

Q-Injection points subject to accelerated or localised corrosion may be treated as _____. a) b) c) d)

The focal point of an inspection circuit Separate inspection circuits Piping that must be renewed on a regular schedule Locations where corrosion inhibitors must be used

Q- The recommended upstream limit of inspection of an injection point is a minimum of: a) b) c) d)

12 feet or 3 pipe lengths whichever is smaller 12 inches or 3 pipe diameters whichever is smaller 12 inches or 3 pipe diameters whichever is greater 12 feet or 3 pipe lengths which is greater

Q- The recommended downstream limit of inspection of an injection point is a minimum of; a) Second change in flow direction past the injection point, or 25 feet beyond the first change in flow direction whichever is less b) Second change in flow direction past the injection point, or 25 feet beyond the first change in flow direction whichever is greater c) Second change in flow direction past the injection point, or 25 inches beyond the first change in flow direction whichever is less d) Second change in flow direction past the injection point, or 25 inches beyond the first change in flow direction whichever is greater. Q- The recommended upstream limit of inspection of an injection point for an 8 inches catalytic line is a minimum of: a) b) c) d)

12 feet or 3 pipe lengths whichever is smaller 12 inches or 3 pipe diameters whichever is smaller 24 inches 12 feet or 3 pipe lengths which is greater

Q- Select thickness measurement locations (TMLs) within injection point circuits subjected to localised corrosion according to the following guidelines. Select the one that does not belong. a) Establish TMLs on appropriate fittings within the injection point circuit. b) Establish at least one TML at a location at least 25 feet beyond the downstream limit of the injection point. c) Establish TMLs on the pipe wall at location of expected pipe wall impingement or injected fluid. d) Establish TMLs at both the upstream and downstream limits of the injection point circuit. Q- What are the preferred methods of inspecting injection points ? a) b) c) d)

Radiography and / or ultrasonic Hammer test and / or radiograph Ultrasonic and / or liquid penetrant Liquid penetrant and / or eddy current.

17- During periodic scheduled inspections, more extensive inspection should be applied to an area beginning ______ upstream of the injection nozzle and continuing for at least ______ pipe diameters downstream of the injection point. a) b) c) d)

10 inches, 20 12 feet, 10 12 inches, 10 10 feet, 10

18- Why should deadlegs in piping be inspected? (API574-7.4.3) a) API 510 mandates the inspection of deadlegs b) Acid products and debris build up in deadlegs c) The corrosion rate in deadlegs can vary significantly from adjacent active piping. d) Caustic products and debris build up in deadlegs.

5.6 CMLs 腐蚀监测点

5.6.1 General 总则 API 574和API 571有对CMLS的选择建议: 在选择CML的性质时应考虑潜在的局部腐蚀和服务特定的腐蚀.不同的CML类型有:    

厚度测量应力开裂检查保温层下腐蚀检测(CUI) 高温氢侵蚀

5.6.2 CML Monitoring CML监控每个管道系统有不同的CMLS监测要求,比如; 在在高失效后果与较高的腐蚀速率或局部腐蚀通常需要更多的CML探测点. 在某些管道回路,如果腐蚀率较低,咨询腐蚀专家/工程师的情况下,CMLs 可以减少或完全不需要. 列如 olefin plant cold side piping, anhydrous ammonia piping, clean noncorrosive hydrocarbon product, or high-alloy piping for product purity.烯烃厂冷端管道,无水氨管道,干净无腐蚀性烃类产品, 纯度高产品合金管道.

The (1) thinnest reading or an (2) average of several measurement readings taken within the area of a examination point shall be recorded and used to calculate corrosion rates, remaining life, and the next inspection date in accordance with Section 7. TML/CML 管道(1) 最薄的读数或 (2) 平均值可用于计算腐蚀速率与管道剩余使用寿命并且确定下一个检验日期 (按照第七章, 计算腐蚀速率与管道剩余使用寿命) ISO图纸上应标明CMLs 允许重复的测量位置.

ISO图纸上应标明CMLs 允许重复的测量位置.

5.6.3 CML Selection 选择在选择或调整 CML 的数量和位置时, 检验员必须对预期的腐蚀模式以及相关的设备有所经历. CML 类型, 数量和位置: 取决于(1) 以前的检查结果, (2) 预期的腐蚀和 (3) 损坏的模式和 (4) 容液流失潜在后果. CMLs 监控范围, 应适当足够的分布在管道系统主要部件和链接处.

A number of corrosion processes common to refining and petrochemical units are relatively uniform in nature, resulting in a fairly constant rate of pipe wall reduction independent of location within the piping circuit, either axially or circumferentially. Examples of such corrosion phenomena include high temperature sulfur corrosion and sour water corrosion (provided velocities are not so high as to cause local corrosion/erosion of elbows, tees, and other similar items). 均匀腐蚀与CML数量减少一些常见的炼油和石化装置的腐蚀过程是比较均匀的性质(容液速度低于造成局部腐蚀/侵蚀, 注意点是弯头,三通等流向变化的管配) CML数量可以相应的减少. - 高温硫腐蚀 High-temperature sulfur corrosion - 酸性水腐蚀 Sour water corrosion

以下任一特性的管道系统需要更多CMLs :  在发生泄漏的紧急下会造成很大的安全与环境事故,  较高的预期或经历的腐蚀速率,  较高的局部腐蚀潜力,  管道系统复杂性如更多的配件/分枝/死角/注射点,等,  较高的保温层腐蚀. 以下任一特性的管道系统可以减少CMLs  发生泄漏的紧急是造成很小的安全与环境事故,  相对无腐蚀的管道系统,  长/直管道系统.

CMLs can be eliminated for piping systems with any of the following characteristics: 以下管道系统特征可以排除CMLs :  发生泄漏的紧急情况时对安全/环境造成极小的影响  无腐蚀性系统  不受系统工艺参数的变化导致腐蚀的发生

在容易受到局部腐蚀或受腐蚀开裂或需要CMLs大幅减少的情况时应征询腐蚀专家关于CMLs 的适当位置和数量.

5.7 Condition Monitoring Methods 状况监测方法

5.7 Condition Monitoring Methods 状态监测方法 5.7.1 UT and RT 超声/射线  ASME BPVC Section V, Article 23, and Section SE–797 超声波测厚仪测量.  NPS 2小口径管道或较小, 超声波测厚仪测量可能需要专门的设备;例如微型探头和/或弧形弯曲接触面以及特定的校准块.  当超声波探伤管体温度超过150oF(65oC ), 仪器仪表/耦合剂/程序应当重新审批.  管道直径NPS 1或更小的首选是;射线剖面技术,特别是在保温层系统或在非均匀或局部腐蚀被怀疑的管道.如有必要,后续UT可以被用来详细获取与记录,个别区域实际厚度.

Profile Radiography 射线剖面技术

超声波测量精度降低因素,包括以下内容： •仪器校准不当, • 表面涂料或氧化皮, • 显着的表面粗糙度, • 弯曲表面上探头摆动(小管径), • 材料的缺陷, 例如母材分层, • 温度的影响(在高于150oF/65oC), • 探测器屏幕分解力低, • 典型的数字测厚仪,厚度小于1 /8英寸(3.2毫米), • 探头的接触耦合太多太少.

有效的腐蚀速率测定重要的是,量尽可能重复在同样位置探测最薄点,也可以从几个读数的平均值得到计算数据. 因维修拆卸的管道, 也可以直观的用机械测量仪测壁厚或坑深度.

5.7.2 Other NDE Techniques for Piping Systems 其他无损检测技术除了厚度监控其他的无损探伤技术可以用来其他特定类型的损伤机理. 在时检查员应咨询腐蚀专家或工程师,以帮助定义损伤机理,型类,选择合适的无损探伤方法和探伤程度. API 571对不同的损伤机理提供一些适当的检查技术指导.

无损检测技术包括以下内容 • 磁粉检验ASME BPVC, Section V, Article 7, • 液体渗透检查 ASME BPVC, Section V, Article 6, • 射线探伤 ASME BPVC, Section V, Article 2, • 超声波探伤ASME BPVC, Section V, Article 4, 5, 23, • 交流电漏磁检测 ACFM, • 涡流检测ASME BPVC, Section V, Article 8, • 现场金相复制识别冶金变化 Metallographic Replica, • 声发射检查. ASME BPVC, Section V, Article 11 & 12, • 热成像检查. Infrared thermography, • 渗漏试验ASME BPVC Section V, Article 10, • 长范围 UT (LRUT-Lamb).

5.7.3 Surface Preparation for NDE 表面处理适当的表面处理满足目视与不同的无损探伤方法. 5.7.4 UT Shear Wave Examiners 超声波检验员当业主/用户的需要以下的情况时, 超声波检验员必须拥有合格资质证  从外部表面探测内部缺陷  检测,鉴定, 缺陷大小  从外部表面检测缺陷/收集数据作为管道 FFS 适用性评价

5.7.3 Surface Preparation for NDE 表面处理适当的表面处理满足目视与不同的无损探伤方法. 5.7.4 UT Shear Wave Examiners 超声波检验员当业主/用户的需要以下的情况时, 超声波检验员必须拥有合格资质证  从外部表面探测内部缺陷  检测,鉴定, 缺陷大小  从外部表面检测缺陷/收集数据作为管道 FFS 适用性评价

5.8 Pressure Testing of Piping Systems - General 管道系统的压力测试-常规

5.8 Pressure Testing of Piping Systems—General 压力测试通常不作为常规检查的一部分进行例外情况包括:   

美国海岸警备队要求过水管道和当地司法管辖区的要求管道时改建焊接后检查员或工程师的指定

其他:  压力测试ASME B31.3要求进行.  压力测试的其他注意事项应按照 API 574, API 579-1/ ASME FFS-1 & ASME PCC-2.  业主/用户指定下也可以进行较低的压力用于管道系统气密性实验.

注意项:  热处理后进行  工程师应检讨支撑结构和基础设计是适合的水压负荷  特别是对高温下使用的设备,实验压力避免超过90％的材料 SMYS (在试验温度的屈服强度值)

5.8.1 Test Fluid 测试液测试流体是水,除非由于冻结或其他对管道系统或工艺流程有不利影响或损坏的可能性或实验水会被污染,导致被释放时对环境带来危害.  

在上述的情况下合适的无毒液体能体用水为实验液. 如果是易燃液体,闪点至少应为120oF / 49oC

SS 300(奥氏体)系列不锈钢实验液要求：  

饮用水(总氯浓度小于250ppm,用氯或臭氧消毒) 去离子水或蒸汽冷凝水(总氯浓度小于50ppm-非游离氯浓度)

For sensitized austenitic stainless steel piping subject to polythionic stress corrosion cracking, consideration should be given to using an alkaline-water solution for pressure testing (see NACE RP 0170).敏化奥氏体不锈钢”连多硫酸” 应力腐蚀开裂，应考虑使用碱性水溶液进行压力测试(见NACE RP 0170) NACE RP0170-2004_奥氏体不锈钢和其它奥氏体合金在精炼设备停机期间连多硫酸应力腐蚀开裂的防推护荐做法

After testing is completed, the piping should be thoroughly drained (all highpoint vents should be open during draining), air blown, or otherwise dried. If potable water is not available or if immediate draining and drying is not possible, water having a very low chloride level, higher pH (>10), and inhibitor addition may be considered to reduce the risk of pitting and microbiologically induced corrosion. 测试完成后，管道应彻底清理, 吹干,燥处理.如果立即排水,吹干. 在不能及时的吹干处理的情况时, 为了降低点蚀腐蚀与微生物腐蚀的风险,可以做以下考虑;  pH值(>10),  非常低氯离子含量的试验用水  添加抑制剂

5.8.2 Pneumatic Pressure Tests 气压测试 A pneumatic (or hydro-pneumatic) pressure test may be used when it is impracticable to hydrostatically test due to temperature, structural, or process limitations. However, the potential risks to personnel and property of pneumatic testing shall be considered when carrying out such a test. As a minimum, the inspection precautions contained in ASME B31.3 shall be applied in any pneumatic testing. 由于温度,结构,工艺的限制不切实际做水压测试时,可以用气压测试替代. 在执行气动压力测试带来的人员安全, 设备破坏隐患应当充分考虑. ASME B31.3中所含的检查注意事项应遵守.

气动压力测试

5.8.3 Test Temperature and Brittle Fracture Considerations 水压试验:测试温度和脆性断裂的注意事项在室温下,一些碳钢,低合金钢,高合金钢,因受到工作环境的接触(温度)导致脆化 (碳化,石墨化,西格玛相等),这些受影响的管道当受压时具产生脆性破裂的隐患. 一些导致钢材的脆性断裂失败,的情况有: (1) 当管道温度低于材料延性转脆温度, (2) 在室温下,当水压升到试验压力的25%时或 (3) 当水压升至8 ksi 时(以较低者为准). 水压试验,特别是气动压力测试前潜在脆性破坏应由工程师评估. 回火脆化低合金材料如 21/4Cr-1Mo 应给予特别关注. 注:在环境温度下,碳,低合金,钢,包括高合金钢脆化服务经过运作过程中,材料机械性能可能变质包括 “脆性”.

Sigma Phase

Sigma Phase

Graphitization

Evaluating the condition & remaining life of older power plants Eyckmans Marc - Product Manager Laire Charles- Product Manager D'ambros Laurent – Engineer LABORELEC - BELGIUM Failure analysis & Material assessment in plants http://www.ndt.net/article/wcndt00/papers/idn022/idn022.htm

水压实验温度要求: 压力测试,降低脆性断裂降风险的预防措施: • 管道壁厚是超过 2” (5 cm) 实验温度应当保持在30°F (17°C) 高于 MDMT • 管道壁厚等于或小于 2” (5 cm) 实验温度应当保持在10° F ( 6°C) 高于 MDMT 试验温度不必超过120° F(50°C), 除非管材资料有所要求.

5.8.4 Precautions and Procedures 注意事项及程序实验目视不能再高于 MAWP 压力下进行. 实验时,因压力的关系,以下管件要做相应的防护措施： ASME B31.3 限制泄压阀, 玻璃液位计,压力表,膨胀弯, 爆破片,膨胀弯,等,进行盲堵,拆卸或降低试验压力措施. ASME B16.34 限制截止阀 (盲堵,确保不超压) 完成后的耐压试验,上述管件应当相应的复位施加压力测试之前, 应采取适当的预防措施和明确的工作程序,以确保人员安全.

5.8.5 Pressure Testing Alternatives 压力测试的替代大修或改造后,如试压不执行,合适的无损探应规定并进行.这样的替代需要工程师/检查员已批准认可. 对于UT被取代的射线检测情况下.必须由合格超声探伤做检测. 参考文件: ASME B31 Code Case 179/181,对最终连接焊口 Tie-in joint (黄金焊道)不做水压试验和焊接返修相关的解释.

5.9 Material Verification and Traceability 材料验证和可追溯性检查员应核实维修所选用的材料规格和建造所用的材料是一致的. 材料验证程序应符合 API 578. 运用风险评估程序,按照风险级别的要求,业主/用户甚至可以要求 100%PMI 测试核查或在风险级别较低的设备进行百分比采样.

不经意的材料替代在修理或改装合金材料管道系统, 因不正确的材料选择无意中取代合适的管道材料引起管道系统组件失败. 解决方案有: 授权检验员, 考虑是否需要作进一步验证现有的管道材料, 进一步的验证的程度将取决于:  

错误选材引起的失效后果进一步选材错误的概率

这一评估,可能导致追溯性的PMI测试(retroactive).

解决现有的合金管道系统(无意中)错误材料替代.  API 578材料验证程序处理更换,这可能包括风险排名程序优先级别处理,  业主/用户,授权管道检查和腐蚀专家的共同咨询下应建立一个更换这些元件时间表,  授权检查员必要时,应定期使用合适的无损探伤方法,检测受到影响的组件直至正确更换.

5.10 Inspection of Valves 阀门检查一般上,由于阀门的构造和管道不一样, 不进行厚度检测. 当阀门从管道系统拆卸时, 进行内部目视,发现不寻常的腐蚀模式时向授权检验员报告. 高温工作阀门显著受到温差循环应定期热疲劳开裂检查.例如催化重整装置的 (1) 再生与 (2)蒸汽清洗-管道系统等

When valve body and/or closure pressure tests are performed after servicing, they should be conducted in accordance with API 598. 阀门维修后- 阀体/关闭压力测试-应按照 API 598- API Standard 598, Valve Inspection and Testing 进行. 控制阀或其他节流阀; 尤其是在高压降和泥浆服务, 阀门下游孔板组件容易受到局部腐蚀/侵蚀. 该阀门应定期拆卸进行内部检查. 关键止回阀; 应定期做目视和内部检查, 以确保能保证流体逆转回流. 除了特殊情况,关键止回阀的泄漏检查通常不是必需的.

5.11 In-service Inspection of Welds 焊缝检查管道新建,维修与改装, 焊缝目视是必然的检验项目. 然而在在职管道,焊道上的轮廓射线检查或内部目视检验方法,其检验重点是观察-”焊缝选择性腐蚀”. 当发现”焊缝选择性腐蚀”被发现时,应在受影响的管道系统上,额外的增加焊缝检查比例. API 577 有对焊缝检查提供额外的作业指导.

.

由于不同的无损探伤方法对焊缝非连贯的探测性不同, 有异于建造时用的无损探伤方法，可能会探测出建造遗留的缺陷. 这缺陷并非与管线后来的使用用任何的关系. 为此在在职管道检验时运用原始制造过程中指定的探伤类型往往是一个很好的做法

在职管道焊接检测时如果被检测到裂纹等缺陷,相关局域应进一步的运用射线(焊接验收级别)或超声探伤方法检查,评估缺陷的大小. 检验员应当分析以确定裂纹等的缺陷是否是从原来新建时焊接造成的或者是从管道在职运作所造成的环境开裂.

http://www.bam.de/en/kompetenzen/fachabteilungen/abteilung_8/fg83/fg83_ag5.htm

Crack-like flaws and environmental cracking shall be assessed by an engineer in accordance with API 579-1/ASME FFS-1 and/or corrosion specialist. Preferential weld corrosion shall be assessed by the inspector. Issues to consider. when assessing the quality of existing welds include the following:           

original fabrication inspection method and acceptance criteria; extent, magnitude, and orientation of imperfections; length of time in service; operating versus design conditions; presence of secondary piping stresses (residual and thermal); potential for fatigue loads (mechanical and thermal); primary or secondary piping system; potential for impact or transient loads; potential for environmental cracking; repair and heat treatment history; weld hardness.

焊缝质量评估职责;  裂纹状缺陷和环境开裂 (crack-like & SCC) 应由工程师按照API 5791/ASME FFS-1或腐蚀专家评估  管道焊缝选择性腐蚀 (preferential weld corrosion) 应由授权检查员评估. 评估现有的焊缝质量时要考虑的问题包括以下：           

原制造检验方法和验收标准, 缺陷的范围,大小和位置/方向, 管线在职时间, 操作条件与设计条件, 管道二次应力- (残留和热), 潜在的疲劳载荷, 主系统或辅助系统, 潜在冲击或瞬态负载, 潜在的环境开裂, 维修和热处理的历史, 焊缝硬度,

ASME B31.3 验收标准旨在适用于新建设上 “采样” 焊缝, 而不仅仅是 100%, 在役管道在焊缝检查过程中,有的焊缝因上述新建时的采样的因素, 或许存在漏检超出标准允许的缺陷.这些受影响的管路然而新建时作为接受条件,进行水压试验仍然满意的运作. 特别是小口径管道, 一般在新建时不做任何射线或超声探伤.为此在役管道焊接件无损探伤评估,它可能无法适当地使用原来的新建造 ASME B31.3 中焊接质量验收标准

5.12 Inspection of Flanged Joints 检查法兰接头法兰接头应检查泄漏现象, 如污渍/堆积物或滴水. 泄漏液可能会导致法兰紧固件和阀盖紧固件腐蚀或环境开裂. 法兰连接面和法兰垫圈应检查服务状况,变形等. 如果法兰明显弯曲或扭曲, 在采取纠正行动之前,法兰等级,标记, 厚度等,核对,查看是否法兰/配件满足设计要求.

法兰紧固件应目视检查腐蚀和螺纹啮合.紧固件螺纹应完全啮合或缺少不多于一个线程螺纹啮合. 应对新安装的紧固件和衬垫上的标记进行检查，以确定是否符合 ASME/ASTM材料规范要求. ASME PCC- 1 有对法兰接头的检查指导 ASME PCC-1, Guidelines for Pressure Boundary Bolted Flange Joint Assembly

5.13 Inspection Organization Audits 检验机构审计检验机构应定期进行审核,以确定是否满足此检查规范的要求  审核小组一般是从业主/客户另个厂区或对石油化工行检验经验丰富的第三方或业主/第三方组合. 审计小组应当至少确定：         

规范要求和原则得到满足所有业主用户的责任正在明确的定义检查计划内容覆盖(相关管道系统) 检查的时间间隔和程度足以覆盖(相关管道系统) 报告审核小组的调查结果提交给业主/用户对发现的不合格项, 授权检验机构应当采取必要的纠正措施每个组织都需要建立系统的跟踪和完成审计结果提交审计纠正结果给审计小组核查上述信息,审查,纠正文件等应当归档以供后续审计审查.

42) Different types of inspection and surveillance are appropriate depending on the circumstances and the piping system. Pick the one that does not belong in the following list:a) b) c) d)

Internal and external visual inspection Thickness measurement inspection Vibrating piping inspection Chemical analysis inspection

43) Internal visual inspections are ______ on piping unless it is a large diameter transfer line, duct, catalyst line or other large diameter piping system. a) b) c) d)

The most effective inspection The most useful means of inspection Not normally performed The major means of inspection

44) Name an additional opportunity for a normal non-destructive internal inspection of piping. a) b) c) d)

When the piping fails and the interior is revealed When maintenance asks for an internal inspection When piping flanges are disconnected When a fire occurs and the pipe is in the fire

45) Why is thickness measurement inspection performed? a) To satisfy jurisdictional requirements b) To determine the internal condition and remaining thickness of the piping components c) To determine the external condition and amount of deposits inside the piping d) To satisfy heat transfer requirements of the piping

46) Who performs a thickness measurement inspection? a) b) c) d)

The operator or control man The inspector or examiner The maintenance workers or supervisor The Jurisdiction or OSHA

47) When corrosion product build-up is noted during an external visual inspection at a pipe support contact area, lifting of such supports may be required for inspection. When doing this, care should be: a) b) c) d)

Exercised if the piping is in-service Used when determining the course of action Practiced so as not to disturb the supports Taken that a complete record of the problem is made

8.What is the best thing to do with dead legs that are no longer required? a) b) c) d)

Ultrasonically inspect often Radiograph often Inspect often Remove them

9) Risk based inspections include which of the following: a) b) c) d)

Likelihood assessment Consequence analysis Operating and inspection histories All of the above

10) An RBI assessment can be used to alter the inspection strategy provided: a) b) c) d)

The degradation methods are identified The RBI is fully documented. A third party conducts the RBI Both A and B above

11) Which one of the following is not a specific type of an area of deterioration? a) b) c) d)

Rectifier performance Injection points Deadlegs Environmental cracking

6. For a typical “injection point pipe circuit” starts upstream of injection point from a distance of a) b) c) d)

3 times pipe diameter or 12 inches which ever is greater 2 times pipe diameter or 12 inches which ever is greater Fixed 12 inches irrespective of pipe diameter None of the above

15. Select thickness measurement locations (TMLs) within injection point circuits subjected to localised corrosion according to the following guidelines. Select the one that does not belong. a) Establish TMLs on appropriate fittings within the injection point circuit. b) Establish at least one TML at a location at least 25 feet beyond the downstream limit of the injection point. c) Establish TMLs on the pipe wall at location of expected pipe wall impingement or injected fluid. d) Establish TMLs at both the upstream and downstream limits of the injection point circuit.

12) Injection points subject to accelerated or localised corrosion may be treated as __________. a) b) c) d)

The focal point of an inspection circuit Separate inspection circuits Piping that must be renewed on a regular schedule Locations where corrosion inhibitors must be used

13) The recommended upstream limit of inspection of an injection point is a minimum of: a) b) c) d)

12 feet or 3 pipe lengths whichever is smaller 12 inches or 3 pipe diameters whichever is smaller 12 inches or 3 pipe diameters whichever is greater 12 feet or 3 pipe lengths which is greater

14) The recommended downstream limit of inspection of an injection point is a minimum of a) Second change in flow direction past the injection point, or 25 feet beyond the first change in flow direction whichever is less b) Second change in flow direction past the injection point, or 25 feet beyond the first change in flow direction whichever is greater c) Second change in flow direction past the injection point, or 25 inches beyond the first change in flow direction whichever is less d) Second change in flow direction past the injection point, or 25 inches beyond the first change in flow direction whichever is greater.

16) What are the preferred methods of inspecting injection points ? a) b) c) d)

Radiography and / or ultrasonic Hammer test and / or radiograph Ultrasonic and / or liquid penetrant Liquid penetrant and / or eddy current.

17) During periodic scheduled inspections, more extensive inspection should be applied to an area beginning __________ upstream of the injection nozzle and continuing for at least __________ pipe diameters downstream of the injection point. a) b) c) d)

10 inches, 20 12 feet, 10 12 inches, 10 10 feet, 10

18) Why should deadlegs in piping be inspected? a) API 510 mandates the inspection of deadlegs b) Acid products and debris build up in deadlegs c) The corrosion rate in deadlegs can vary significantly from adjacent active piping. d) Caustic products and debris build up in deadlegs. 19) Both the stagnant end and the connection to an active line of a deadleg should be monitored. In a hot piping system, why does the high point of a deadleg corrode and need to be inspected? a) b) c) d)

Corrosion occurs due to directed currents set up in the deadleg Erosion occurs due to convective currents set up in the deadleg. Corrosion occurs due to convective currents set up in the deadleg Erosion occurs due to directed currents et up in the deadleg

20)What is the best thing to do with deadlegs that are no longer in service? a) b) c) d)

Ultrasonically inspect often Radiograph often Inspect often Remove them

21)What are the most common forms of corrosion under insulation (CUI). a) Localised corrosion of non-ferrous metals and chloride stress corrosion cracking of carbon steel. b) Localised corrosion of chrome-moly steel and chloride stress corrosion cracking of ferritic stainless steel. c) Localised corrosion of carbon steel and chloride stress corrosion cracking of austenitic stainless steel d) Localised corrosion of nickel-silicon alloy and caustic stress corrosion of austenitic stainless steel

22)What climatic area may require a very active program for corrosion under insulation? a) b) c) d)

Cooler northern continent locations. Cooler direr, mid-continent locations Warmer, marine locations Warmer drier, desert locations

23)Certain areas and types of piping systems are potentially more susceptible to corrosion under insulation. Which of the items listed is not susceptible to CUI? a) Areas exposed to mist over-spray from cooling water towers. b) Carbon steel piping systems that normally operate in-service above 250 degrees but are in intermittent service. c) Deadlegs and attachments that protrude from insulated piping and operate at a different temperature than the temperature of the active line. d) Carbon steel piping systems, operating between 250 degrees F and 600 degrees F.

24) What location is subject to corrosion under insulation and inspection contributes to it? a) Locations where pipe hangers and other supports exist. b) Locations where insulator has been stripped to permit inspection of the piping. c) Locations where insulation plugs have been removed to permit piping thickness measurements. d) Locations where there is damaged or missing insulation jacketing. 25) Soil-to-air (S/A) interfaces for buried piping are a location where localised corrosion may take place. If the buried part is excavated for inspection, how deep should the excavation be to determine if there is hidden damage? a) b) c) d)

12 to 18 inches 6 to 12 inches 12 to 24 inches 6 to 18 inches

26) At concrete-to-air and asphalt-to-air interfaces of buried piping without cathodic protection, the inspector look for evidence that the caulking or seal at the interface has deteriorated and allowed moisture ingress. If such a condition exists on piping systems over __________ years old, it may be necessary to inspect for corrosion beneath the surface before resealing the joint. a) b) c) d)

8 5 15 10

27) An example of service-specific and localised corrosion is:a) Corrosion under insulation in areas exposed to steam vents b) Unanticipated acid or caustic carryover from processes into non-alloyed piping c) Corrosion in deadlegs d) Corrosion of underground piping at soil-to-air interface where it ingresses or egresses.

28)Erosion can be defined as: (2013 June) a) Galvanic corrosion of a material where uniform losses occur b) Removal of surface material by action of numerous impacts of solid or liquid particles c) Gradual loss of material by a corrosive medium acting uniformly on the material surface d) Pitting on the surface of a material to the extent that a rough uniform loss occurs 29)A combination of corrosion and erosion results in significantly greater metal loss that can be expected from corrosion or erosion alone. This type of loss occurs at: (2013 June) a) High-velocity and high-turbulence areas b) Areas where condensation or exposure to wet hydrogen sulphide or carbonates occur c) Surface-to-air interfaces f buried piping d) Areas where gradual loss of material occurs because of a corrosive medium

30) Environmental cracking of austenite stainless steels is caused many times by:a) b) c) d)

Exposing areas to high-velocity and high-turbulence streams Excessive cyclic stresses that are often very low Exposure to chlorides from salt water, wash-up water, etc. Creep of the material by long time exposure to high temperature and stress

31) When the inspector suspects or is advised that specific piping circuits may be susceptible to environmental cracking, the inspector should: a) b) c) d)

Call in a piping engineer for consultation. Investigate the history of the piping circuit. Obtain advice from a Metallurgical Engineer. Schedule supplemental inspections.

32) If environmental cracking is detected during internal inspection of pressure vessels, what should the inspector do? (2013 June) a) The inspector should designate appropriate piping spools upstream and downstream of the vessel to be inspected if piping is susceptible to environmental cracking. b) The inspector should consult with a metallurgical engineer to determine extent of the problems c) The inspector should review history of adjacent piping to determine if it has ever been affected. d) The inspector should consult with a piping engineer to determine the extent of the problems.

33)If external or internal coatings or refractory liners on a piping circuit are in good condition, what should an inspector do? (2013 June) a) b) c) d)

After inspection, select a portion of the liner for removal The entire liner should be removed for inspection Selected portions of the liner should be removed for inspection After inspection, if any separation, breaks, holes or blisters are found, it may be necessary to remove portions of the lining to determine the condition under it.

34)What course of action should be followed it a coating of coke is found on the interior of a large pipe of a reactor on a Fluid Catalytic Cracking Unit? (2013 June) a) Determine whether such deposits have active corrosion beneath them. If corrosion is present, thorough inspection in selected areas may be required. b) The coke deposits should be removed from the area for inspection. c) The coke deposits may be ignored – the deposits will probably protect the line from corrosion. d) Consult with a Process Engineer and a Metallurgist on the necessity of removing the coke deposits.

35)Fatigue cracking of piping systems may result from a) Embrittlement of the metal due to it operating below its transition temperature b) Erosion or corrosion / erosion that thin the piping where it cracks c) Excessive cyclic stresses that are often well below the static yield strength of the material d) Environmental cracking caused by stress corrosion due to the presence of caustic, amine, or other substance. 36)Where can fatigue cracking typically be first detected? a) b) c) d)

At points of low-stress intensification such as reinforced nozzles At points of high-stress intensification such as branch connections At points where cyclic stresses are very low At points where there are only bending or compressive stresses.

37) What are the preferred NDE methods for detecting fatigue cracking? (2013 June) a) Eddy current testing ultrasonic A-scan testing, and / or possibly hammer testing b) Liquid penetrant testing, magnetic particle testing and / or possibly acoustic emission testing. c) Visual testing, eddy current testing and / or possibly ultrasonic testing d) Acoustic emission testing, hydro-testing, and / or possibly ultrasonic testing. 38) Creep is dependent on: a) b) c) d)

Time, temperature, and stress Material, product contained, and stress Temperature, corrosive medium, and load Time, product contained and load

39)An example of where creep cracking has been experienced in the industry is in the problems experienced with cracking of 1.25 % Chrome steels operating at temperatures above __________ °F. a) b) c) d)

500 900 1000 1200

40)Brittle fracture can occur in carbon, low-alloy and other ferritic steels at or below __________. a) b) c) d)

140 degree Ambient 100 degree 30 degree

41)Water and aqueous solutions in piping systems may freeze and cause failure because of the a) b) c) d)

Expansion of these materials Contraction of these materials Construction of these materials Decrease of these materials

42)Different types of inspection and surveillance are appropriate depending on the circumstances and the piping system. Pick the one that does not belong in the following list:a) b) c) d)

Internal and external visual inspection Thickness measurement inspection Vibrating piping inspection Chemical analysis inspection

43)Internal visual inspections are __________ on piping unless it is a large diameter transfer line, duct, catalyst line or other large diameter piping system. a) b) c) d)

The most effective inspection The most useful means of inspection Not normally performed The major means of inspection

44)Name an additional opportunity for a normal non-destructive internal inspection of piping. a) b) c) d)

When the piping fails and the interior is revealed When maintenance asks for an internal inspection When piping flanges are disconnected When a fire occurs and the pipe is in the fire

45)Why is thickness measurement inspection performed? a) To satisfy jurisdictional requirements b) To determine the internal condition and remaining thickness of the piping components c) To determine the external condition and amount of deposits inside the piping d) To satisfy heat transfer requirements of the piping 46)Who performs a thickness measurement inspection? a) b) c) d)

The operator or control man The inspector or examiner The maintenance workers or supervisor The Jurisdiction or OSHA

47)When corrosion product build-up is noted during an external visual inspection at a pipe support contact area, lifting of such supports may be required for inspection. When doing this, care should be: (2013 June) a) b) c) d)

Exercised if the piping is in-service Used when determining the course of action Practiced so as not to disturb the supports Taken that a complete record of the problem is made

48)Qualified operating or maintenance personnel also may conduct external visual inspections when: a) b) c) d)

Satisfactory to the owner-user Acceptable to the inspector Agreeable to the maintenance supervisor Permissible to the operation supervisor

49)Who would normally report vibrating or swaying piping to engineering or inspection personnel? a) b) c) d)

Operating personnel Maintenance personnel Jurisdictional personnel OSHA personnel

50)Thermography is used to check for: a) b) c) d)

Vibrating sections of the piping system Detecting localised corrosion in the piping system Abnormal thermal expansion of piping systems Hot spots in refractory lined piping systems

51)Thickness measurement locations (TMLs) are specific _______ along the piping circuit where inspections are to be made a) b) c) d)

Points Areas Items Junctures

52)The minimum thickness at each TML can be located by: a) b) c) d)

Electromagnetic techniques Ultrasonic scanning or radiography Hammer testing MT and / or PT

53)Where appropriate, thickness measurements should include measurements at each of __________ on pipe and fittings: (2013 June) a) b) c) d)

Two quadrants Three locations Four quadrants Six points

54)Where should special attention be placed when taking thickness measurements of an elbow? a) b) c) d)

The outlet end The inlet end The inside and outside radius The sides

55)TMLs should be marked on inspection drawings and __________ to allow repetitive measurements a) b) c) d)

On the inspectors notes On a computer system On the piping system On maintenance department charts

56)What is taken into account by an experienced inspector when selecting TMLs? a) b) c) d)

The amount of corrosion expected The patterns of corrosion that would be expected The number and the cost of reading the TMLs Whether the TMLs are easily accessed

57) In theory, a piping circuit subject to perfectly uniform corrosion could be adequately monitored with __________ TMLs. a) b) c) d)

1 2 3 4

58) More TMLs should be selected for piping systems with any of the following characteristics: a) Low potential for creating a safety or environmental emergency in the event of a leak. b) More complexity in terms of fittings, branches, deadlegs, injection points, etc. c) Relatively non-corrosive piping systems d) Long, straight-run piping systems

59)Fewer TMLs can be selected for piping systems with any of the following characteristics: a) More complexity in terms of fittings, branches, deadlegs, injection points, etc. b) Higher expected or experienced corrosion rates c) Long, straight-run piping systems d) Higher potential for localised corrosion 60)TMLs can be eliminated for piping systems with the following characteristics: a) Higher potential for creating a safety or environmental emergency in the event of a leak. b) Low potential for creating a safety or environmental emergency in the event of a leak. c) Extremely low potential for creating a safety of environmental emergency in the event of a leak. d) More complexity in terms of fittings, branches, deadlegs, injection points, etc.

61)What is usually the most accurate means for obtaining thickness measurements on installed pipe larger than NPS 1? a) b) c) d)

MT UT PT ET

62)What thickness measuring technique does not require the removal of some external piping insulation? a) b) c) d)

AE UT ET RT

63) When ultrasonic thickness measurements are taken above __________ degrees F, instruments couplants, and procedures should be used that will result in accurate measurements at the higher temperature a) b) c) d)

150 175 200 250

64)Typical digital thickness gages may have trouble measuring thickness less than __________ inches. a) b) c) d)

0.2188 0.1875 0.1562 0.1250

65)When pressure testing of piping systems are conducted, they shall be performed in accordance with the requirements of: a) b) c) d)

ASME B31.3 ASME B&PV Code, Section VIII SA B16.5 API 510

66)If a lower pressure test (lower than prescribed by code) is used only for tightness of piping systems, the __________ may designate the pressure a) b) c) d)

Owner-user Inspector Jurisdiction Contractor

67)The preferred medium for a pressure test is __________: a) b) c) d)

Steam Air Water Hydrocarbon

68)If a non-toxic hydrocarbon (flammable) is used as the test medium, the liquid flash point shall be at least __________ °F or greater. a) b) c) d)

95 100 110 120

69)Piping fabricated of or having components of 300 series stainless steel should be tested with __________. a) b) c) d)

Water with a pH of 4 Water with a pH of 6 Water with a chloride content of less than 400 ppm chlorides Steam condensates

70)For sensitised austenitic stainless steel, piping subject to polythionic stress corrosion cracking, consideration should be given to using __________ for pressure testing a) b) c) d)

An acidic-water solution An alkaline-water solution A water with a pH of 5 A water with a pH of 4

71)When a pipe requires post weld heat treatment, when should the pressure test be performed? a) b) c) d)

During heat treatment Before any heat treatment After any heat treatment No test is required

72)During a pressure test, where test pressure will exceed the set pressure of the safety relieve valve or valves on a piping system, the safety relief valve or valves should be __________ when carrying out the test. a) b) c) d)

Altered by screwing down the adjusting screw Reset to exceed the test pressure Checked or tested Removed or blanked

73)When using block valves to isolate a piping system for pressure test, what precaution should be taken? a) b) c) d)

Do not use a globe valve during a test Make sure the packing gland of the valve is tight Do not exceed the permissible seat pressure of the valve Check the bonnet bolts to make sure they are tight

74)Several methods may be used to verify that the correct alloy piping is in a system. Pick the incorrect method from the list below: a) b) c) d)

Holography Optical spectrographic analyser X-ray fluorescent analyser Chemical spot checking

75)Name a part of a piping system that thickness measurements are not normally routinely taken. a) b) c) d)

Elbows Expansion loops Tees Valves

76)If environmental cracking is found during in-service inspection of welds, who assesses the problem? a) b) c) d)

Owner-user Inspector Piping Engineer Metallurgist

77)If an inspector finds an imperfection in an original fabrication weld and analysis is required to assess the impact of the weld quality on piping integrity, which of the following may perform the analysis? a) b) c) d)

An API 510 inspector, WPS inspector, A Pressure Vessel Engineer An API 570 inspector, a CWI inspector, a piping engineer An owner-user, a B31.3 inspector, an industrial engineer A Jurisdictional representative, a API 574 inspector, a Chemical Engineer

78) According to API 570, some welds in a piping system that has been subjected to radiography according to ASME B31.3: a) Will meet random radiograph requirements and will perform satisfactorily in-service without a hydrofest b) Will not meet random radiograph requirements, and will not perform satisfactorily in-service even though hydrotested. c) Will meet random radiograph requirements, and will not perform satisfactorily in-service after a hydrotest d) Will not meet random radiograph requirements, but will still perform satisfactorily in-service after being hydrotested.

ASMEB31.3, 344.1.3 random spot examination:3 a specified partial examination of a percentage of a specified kind of item in a designated lot of piping2 2

A designated lot is that quantity of piping to be considered in applying the requirements for examination in this Code. The quantity or extent of a designated lot should be established by agreement between the contracting parties before the start of work. More than one kind of designated lot may be established for different kinds of piping work.

3

Random or spot examination will not ensure a fabrication product of a prescribed quality level throughout. Items not examined in a lot of piping represented by such examination may contain defects which further examination could disclose. Specifically, if all radiographically disclosable weld defects must be eliminated from a lot of piping, 100% radiographic examination must be specified.

79)How should fasteners and gaskets be examined to determine whether they meet the material specifications: a) All fasteners and gaskets should be checked to see if their markings are correct according to ASME and ASTM standards b) A representative sample of the fasteners and gaskets should be checked to see if their markings are correct according to ASME and ASTM standards c) Purchase records of all fasteners and gaskets should be checked to see if the fasteners and gaskets meet ASME and ASTM standards d) A representative sample of the purchase records of fasteners and gaskets should be checked to see if the fasteners and gaskets meet ASME and ASTM standards.

81. What course of action is called for when an inspector finds a flange joint that has been clamped and pumped with sealant? (2013 June) a) Disassemble the flange joint; renew the fasteners and gaskets. The flanges may also require renewal or repair. b) Renew all the fasteners and renew the gasket if leakage is still apparent. c) Check for leakage at the bolts; if re-pumping is contemplated, affected fasteners should be renewed. d) No action is required since the joint has been pumped with a sealant. 80) When checking flange and valve bonnet bolts for corrosion, what type of NDT is usually used? a) b) c) d)

RT UT VT AE

http://photobucket.com/images/charliechong?page=1

Sec~6 6 Interval/Frequency and Extent of Inspection 检验间隔时间/频率和程度

6 Interval / Frequency and Extent of Inspection 检验间隔时间/频率和程度 6.1 General 概要 6.2 Inspection During Installation and Service Changes 检查在安装和服务过程中的变化 6.3 Piping Inspection Planning 管道检测规划 6.4 Extent of Visual External and CUI Inspections 外观与CUI 查程度 6.5 Extent of Thickness Measurement Inspection 厚度测量检验程度 6.6 Extent of Small-bore, Auxiliary Piping, and Threaded-connections Inspection 小口径,辅助管道和螺纹连接的检查程度 6.7 Inspection and Maintenance of Pressure-relieving Devices (PRD) 泄压装置的检查和维护

6.1 General 大纲

6.1 General 大纲意图: API 570 是根据监察代表性的抽样选定管道检验点; 刻意,带意图,合理,准确的评估管道的状况以确保设备的完整性. 检验间隔: 所有的管路系统和泄压装置应按照本节中提供的时间间隔/频率检查.在到期日或之前应进行定期检查或被视为“逾期检查”. 根据API 580风险评估的结果,这时间间隔可延长检验日期,在这期限结束之前不视为“逾期检查” 目的: 设备检验后,应当能提供足够的信息以确定所有设备的重要部分或组件是安全的, 直到下一次的定期检查工作. 内部检验负面影响: 计划进行内部检查时,应当对设备关机和启动带来的增加腐蚀的可能性(启动/关机过程中对空气和水接触等) 进行评估.

设备关机和启动带来的内壁增加腐蚀 (启动/关机过程中对空气和水接触等)

6.2 Inspection During Installation and Service Changes 安装和服务的变化过程中的检验

6.2.1 Piping Installation 管道施工在管道施工安装时,管道应按照施工要求的规范 (ASME B31.3) 检查. 安装检查应包括以下项目: 1. 验证管道是否正确安,管托/支撑/附属结构件等正确安装, 保温层正确安装, 法兰和其他机械连接正确组装管, 道清洁和干燥; 2. 验证泄压装置满足设计要求和正确安装在改造管线施工,创建一个准确的腐蚀速率计算基础点 CML/TML: 舍弃规格标称和最小厚度数据, 记录实际管线壁厚作为厚度基线用来作为初始厚度的厚度测量腐蚀速率计算.

6.2.2 Piping Service Change 管道服务变化如果管道系统的 (1) 服务条件改变 (工艺参数例如容液变化,最大工作压力, 最高和最低工作温度) ,新的检查间隔时间应重新建立, 符合服务条件的更改. 如果管道 (2) 所有权和管道的 (3) 位置有所改变时,设备在重新使用之前,应检查服务条件(工艺参数)是否有所变动.检查间隔应依照需求重新建立.

6.3 Piping Inspection Planning 管道检测规划

6.3.1 General 大纲管道系统上进行检查的频率和程度取决于：  损坏机理(表-1)  发生故障可能会影响的结果 API 571对各种形式影响工艺管道更详细地描述. Section 6.3.4 中定义基于故障的后果的管道的简化的分类,用于建立检的频率和程度. 业主/用户可能会制定一个更广泛的分类方案更准确的评估某些管道系统故障的后果. 后果评估考虑潜在的 (1) 爆炸 (2) 火灾 (3) 中毒 (4) 对环境的影响 (5) 其他相关的潜在影响失效的后果. RBI 基于风险分析检验-是基于(1) 故障概率检和 (2) 失败的后果验策略

在一个有效的评价的结果可以被用来建立一个管道检验策略和定义如下：    

利用相应的检验方法,范围,工具和技术的基础上的预期损伤机理相应的检验频率压力测试要求-修理, 修改,损坏后复位. 减少管道发生故障的概率和后果的预防和减缓行动

6.3.2 RBI for Inspection Planning 运用RBI作为检验计划因素 An RBI assessment may be used to increase or decrease the inspection limits described in Table 2. Similarly, the extent of inspection may be increased or decreased beyond the targets in Table 3, by an RBI assessment. When used to increase inspection interval limits or the extent of inspection, RBI assessments shall be conducted at intervals not to exceed the respective limits in Table 2, or more often if warranted by process, equipment, or consequence changes. These RBI assessments shall be reviewed and approved by a piping engineer and authorized piping inspector at intervals not to exceed the respective limits in Table 2, or more often if warranted by process, equipment or consequence changes. RBI 可以被用来增加或减少表2中所述的检验限制, RBI评估应当在不超过表2中的各自的限制间隔内执行或如果必要因工艺,设备, 或后果变化在更短的时间,重估.

RBI 基于风险分析检验-是基于 (1) 故障概率检和 (2) 故障后果验验策略

6.3.3 Inspection Intervals 检验时间间隔如果RBI不启用的情况：检验时间间隔不超过(最小值) :  法定要求  从腐蚀速率确定一半厚度测量的剩余寿命  表-2允许的最大时间隔. 在有必要时适当的调整检验时间隔,考虑范围有: 腐蚀机理, 生产与工艺条件, 以前的检查历史,当前检查结果.

6.3.4 Piping Service Classes 管道级别 6.3.4.1 General 总则基于发生泄漏潜在的安全和环境影响, 所有工艺管道系统分为不同的管道分类. 这样的分类系统允许额外的检查力度, 重点在较高的分类系统需要在更短的间隔,更广泛的检查以确认其完整性-持续安全运行. 小编: 上述考虑项为: “基于发生泄漏潜在的安全和环境影响” – RBI里的故障模式 (failure scenario)项的一小节, 故障概率(probability)这里没有描述.

Damage mechanism → failure mode → failure Scenario → Consequence

小编: 上述考虑项为: “基于发生泄漏潜在的安全和环境影响” – 受压”溶液特征”是影响RBI COF里的故障模式(failure scenario)项的一小节, 故障概率(probability) 这里没有描述. 例如:失效概率很低的一类管系检验间隔和失效概率很高的一类管系是一样的. 失效情景一般上; Damage mechanism (广义腐蚀) → failure mode (蚀孔)→ failure Scenario (小量泄漏x溶液特征) → Consequence (后果其一:局部火灾)

所有工艺管系系统应分为不同的检验分类; Class 1,2,3,4 + +

所有工艺管道系统应分为不同的管道分类 +,+

管道分类: S/A , CUI, +++

6.3.4.2 Class 1 Services with the highest potential of resulting in an immediate emergency if a leak were to occur are in Class 1. Such an emergency may be safety or environmental in nature. Class 1 如果泄漏发生, 最有潜力导致即时的的安全或环境本质上紧急状况.

Class 1 如果泄漏发生，最有潜力导致即时的的安全或环境本质上紧急: 考虑条件 (a, b, c) 服务因素: 易燃服务,迅速蒸发加压服务,脆性断裂, 3%硫化氢硫化氢,无水氯化氢,氢氟酸

+ plus

温度因素: 自燃温度,常压沸点温度, 操作温度高于沸点温,释放时自冷低于延脆转变温度

+ plus

国家法规环境要求(美国运输和美国海岸卫队法规）

1. Flammable services that can auto-refrigerate and lead to brittle fracture. 易燃服务: 释放时自冷(低于延脆转变温度),并导致脆性断裂, 2. Pressurized services that can rapidly vaporize during release, creating vapors that can collect and form an explosive mixture, such as C2, C3, and C4 streams. Fluids that can rapidly vaporize are those with atmospheric boiling temperatures o o below 50 F (10 C) or where the atmospheric boiling point is below the operating temperature (typically a concern with high-temperature services). 加压服务: 在释放过程中迅速蒸发,形成或集合为爆炸性混合物与常压沸点温度低 o o 于50 F(10 C)或低于操作温度(高温系统), 3. Hydrogen sulfide (greater than 3% weight) in a gaseous stream. 3%硫化氢硫化氢, 4. Anhydrous hydrogen chloride 无水氯化氢, 5. Hydrofluoric acid 氢氟酸, 6. Piping over or adjacent to water and piping over public throughways (refer to Department of Transportation and U.S. Coast Guard regulations for inspection of over water piping). 相邻公共水资源和公共通道上的管路, 7. Flammable services operating above their auto-ignition temperature. 易燃服务: 工作温度高于其自燃温度.

6.3.4.3 Class 2 二类管系 Services not included in other classes are in Class 2. This classification includes the majority of unit process piping and selected off-site piping. Typical examples of these services include but are not necessarily limited to those containing the following: a) on-site hydrocarbons that will slowly vaporize during release such as those operating below the flash point, 内场低于闪点服务;在释放过程中慢慢蒸发 b) hydrogen, fuel gas, and natural gas, 氢,燃料气体,天然气, c) on-site strong acids and caustics. 场区内强酸和碱液. 二类基本上包括大多数的场内,与小部分的场外工艺管系. 那些不归于在其他类别管系(1,3,4)的是归于第2类管系.

Class 2: 此分类包括大多数的处理单元工艺管道和一些场外管道.

6.3.4.4 Class 3 Services that are flammable but do not significantly vaporize when they leak and are not located in high-activity areas are in Class 3. Services that are potentially harmful to human tissue but are located in remote areas may be included in this class. Class 3

可燃物服务,在释放过程中不显着蒸发, 泄漏并非位于高活性区. 位于偏远地区对人体组织有潜在伤害的(蒸汽?,热水?,微害性小?)管系,也可以归于三类服务. Services that are potentially harmful to human tissue but are located in remote areas may be included in this class. (???)

1. on-site hydrocarbons that will not significantly vaporize during release such as those operating below the flash point; 低于闪点服务: 在释放过程中不会显着蒸发的厂区碳氢化合物, 2. distillate and product lines to and from storage and loading; 馏分物和产品,储存和装载管道, 3. tank farm piping; 罐区管道, 4. off-site acids and caustics. 场区外酸液碱溶液管道.

6.3.4.5 Class 4 / 4 类 Services that are “essentially nonflammable -基本上是不可燃的” and nontoxic are in Class 4, as are most utility services. Inspection of Class 4 piping is optional and usually based on reliability needs and business impacts as opposed to safety or environmental impact. Examples of Class 4 service include, but are not necessarily limited to those containing the following:

a) b) c) d) e) f) g)

steam and steam condensate; 蒸汽和蒸汽冷凝水 air; 空气 nitrogen; 氮气 water, including boiler feed water, stripped sour water; 水,包括;锅炉补给水,剥离酸水 lube oil, seal oil; 润滑油,密封油 plumbing and sewers: 生活共用管道和污水管道 ASME B31.3, Category D services; D类服务

Class 4 基本上都是不可燃，无毒的服务

Class 4

蒸汽和蒸汽冷凝水

润滑油, 密封油

ASME B31.3, Category D services

ASME B31.3 Category D Fluid Service: a fluid service in which all the following apply: 1. the fluid handled is nonflammable, nontoxic, and not damaging to human tissues as defined in para. 300.2 处理的流体是不易燃的,无毒的,不损害人体组织 2. the design gage pressure does not exceed 1035 kPa (150 psi) 设计不超过10公斤表压 3. the design temperature is from -29oC (-20oF) through 186oC (366oF) 设计温度范围为-29oC ~ +186oC

6.4 Extent of Visual External & CUI Inspections 外观 & CUI 检查程度

http://www.ndt.net/article/wcndt00/papers/idn751/idn751.htm http://www.ndt.net/article/0298/twomey/twomey.htm

Guided Wave Ultrasonic Testing (GWUT) http://www.tmqc.com.tw/motion.asp?siteid=1002958&menuid=17737&postid=16895 &csw=1

External visual inspections, including inspections for CUI, should be conducted at maximum intervals listed in Table 2 to evaluate items such as those in API 574. Alternatively, external visual inspection intervals can be established by using a valid RBI assessment conducted in accordance with API 580.

应当在表2中列出的最大间隔,或者可以通过使用有效的 RBI 建立间隔

Corrosion under insulation 保温层下的腐蚀

API574, 7.4.4.1 Insulated Piping Systems Susceptible to CUI 易受影响管道系统

7.4.4 CUI External inspection of insulated piping systems should include a review of the insulation system integrity for conditions that could lead to CUI and signs of ongoing CUI. API 570 documents the requirements of a CUI inspection program. Sources of moisture can include rain, water leaks, condensation, deluge systems, and cooling towers. The two forms of CUI are localized corrosion of carbon steel and chloride SCC of austenitic stainless steels. See API 571 for additional details on CUI mechanisms. This section provides guidelines for identifying potential CUI areas for inspection. The extent of a CUI inspection program may vary depending on the local climate. Marine locations in warmer areas may require a very active program, whereas cooler, drier, mid-continent locations may not need as extensive a program. 7.4.4.1 Insulated Piping Systems Susceptible to CUI Certain areas of piping systems are potentially more susceptible to CUI, including: a) b) c) d) e)

f) g) h) i) j) k) l)

those exposed to mist over-spray from cooling water towers; those exposed to steam vents; those exposed to deluge systems; those subject to process spills or ingress of moisture or acid vapors; carbon steel piping systems, including ones insulated for personnel protection, operating between 10°F (–12°C) and 350°F (175°C); CUI is particularly aggressive where operating temperatures cause frequent or continuous condensation and reevaporation of atmospheric moisture; carbon steel piping systems which normally operate in service above 350°F (175°C), but are in intermittent service; dead-legs and attachments that protrude from insulated piping and operate at a different temperature than the operating temperature of the active line; austenitic stainless steel piping systems operating between 120°F (60°C) and 400°F (205°C) (susceptible to chloride SCC); vibrating piping systems that have a tendency to inflict damage to insulation jacketing providing a path for water ingress; steam traced piping systems that can experience tracing leaks, especially at tubing fittings beneath the insulation; piping systems with deteriorated insulation, coatings, and/or wrappings; bulges or staining of the insulation or jacketing system or missing bands (bulges can indicate corrosion product buildup); piping systems susceptible to physical damage of the coating or insulation, thereby, exposing the piping to the environment.

API RECOMMENDED PRACTICE 574 THIRD EDITION, NOVEMBER 2009

7.4.4.2 Typical Locations on Piping Circuits Susceptible to CUI The above noted areas of piping systems can have specific locations within them that are more susceptible to CUI. These areas include the following. a)

All penetrations or breaches in the insulation jacketing systems, such as:

— dead-legs (vents, drains, etc.); — pipe hangers and other supports; — valves and fittings (irregular insulation surfaces); — bolt-on pipe shoes; and — steam and electric tracer tubing penetrations. b) c) d) e) f) g) h)

Termination of insulation at flanges and other piping components. Damaged or missing insulation jacketing. Insulation jacketing seams located on the top of horizontal piping or improperly lapped or sealed insulation jacketing. Termination of insulation in a vertical pipe. Caulking which has hardened, separated, or is missing. Low points in piping systems that have a known breach in the insulation system, including low points in long unsupported piping runs. Carbon or low-alloy steel flanges, bolting, and other components under insulation in high-alloy piping systems.

Particular attention should be given to locations where insulation plugs have been removed to permit piping thickness measurements on insulated piping. These plugs should be promptly replaced and sealed. Several types of removable plugs are commercially available that permit inspection and identification of inspection points for future reference.


API574, 7.4.4.1 Insulated Piping Systems Susceptible to CUI 易受影响管道系统以下为易受保温层腐蚀的管道系统: 1. those exposed to mist over-spray from cooling water towers; 那些接触过喷雾冷却水塔 2. those exposed to steam vents; 那些暴露在蒸汽喷口 3. those exposed to deluge systems; 那些暴露在雨淋系统 4. those subject to process spills or ingress of moisture or acid vapors; 易被工艺媒介溢出或酸性气体/水分渗入 5. carbon steel piping systems, including ones insulated for personnel protection, operating between 10o F (–12oC) and 350oF (175oC); CUI is particularly aggressive where operating temperatures cause frequent or continuous condensation and re-evaporation of atmospheric moisture; 工作温度波动易引起连续凝结和蒸发大气中的水分的工艺管路


6. carbon steel piping systems which normally operate in service above 350oF (175oC), but are in intermittent service; 在高温工作的但间歇服务(这会引起重复的凝结与蒸发-导致一般腐蚀与环境开裂) 7. dead-legs and attachments that protrude from insulated piping and operate at a different temperature than the operating temperature of the active line; 死角和附件绝缘管道伸出，并在不同的温度下运作 8. austenitic stainless steel piping systems operating between 120oF (60oC) and 400oF (205oC) (susceptible to chloride SCC);奥氏体不锈钢管道系统在以上温度波动工作,引起重复的凝结与蒸发-导致环境开裂 9. vibrating piping systems that have a tendency to inflict damage to insulation jacketing providing a path for water ingress; 震动管道(引起保温层破坏) 10. steam traced piping systems that can experience tracing leaks, especially at tubing fittings beneath the insulation; 带蒸汽伴管管道-可能泄露导致保温层潮湿 11. piping systems with deteriorated insulation, coatings, and/or wrappings; bulges or staining of the insulation or jacketing system or missing bands (bulges can indicate corrosion product buildup);管道系统的涂层,保温层,缠绕带劣化的管道 12. piping systems susceptible to physical damage of the coating or insulation, thereby, exposing the piping to the environment. 容易受到物理伤害管道系统 API RECOMMENDED PRACTICE 574 THIRD EDITION, NOVEMBER 2009

API 574 7.4.4.1-表示易受保温层下的腐蚀温度范围 1. 碳钢管道系统(包括人员保护绝缘): 频繁服务温度波动管系 10°F ~ 350°F (-12°C~175 °C) CUI 活跃/积极波动服务温度.因这工作温度段会导致频繁或连续大气中的水分冷凝/蒸发和再冷凝循环. 2. 碳钢通常服务超过 350°F (175°C ), 但在间歇服务. 3. 奥氏体不锈钢管道系统120°F~400°F( 60°C~ 205°C) 之间 (SCC 应力腐蚀开裂)


API 574 7.4.4.1-表示易受保温层下的腐蚀温度范围 1. 碳钢管道系统(包括人员保护绝缘): 频繁服务温度波动管系 10°F ~ 350°F (-12°C~175 °C) 2. 碳钢通常服务超过 350°F (175°C ), 但在间歇服务. 3. 奥氏体不锈钢管道系统 120°F~400°F( 60°C~ 205°C) 之间 (SCC 应力腐蚀开裂)

API 574 7.4.4.1-表示易受保温层下的腐蚀温度范围  铁素体/碳钢/低合金钢点状腐蚀  奥氏体不锈钢管道系统应力腐蚀开裂

铁素体/碳钢/低合金钢点状腐蚀





Piping systems that are known to have a remaining life of over 10 years or that are adequately protected against external corrosion need not be included for the NDE inspection recommended in Table 3. However, the condition of the insulating system or the outer jacketing, such as a cold-box shell, should be observed periodically by operating or other personnel. If deterioration is noted, it should be reported to the inspector. The following are examples of these systems: 已知有剩余年期为10年以上,或得到充分保护免受外部腐蚀的管道系统可以不需要按照表-3所建议进行无损探伤 NDE检验.然而, 操作员或其相关人员应当经常检查保温系统,保温层外护套.任何的衰败应当及时通知授权检验员

上述说的不受 CUI 影响的工艺管线例子有; 1. piping systems insulated effectively to preclude the entrance of moisture,有效地阻止水分渗入的绝缘管道系统 2. jacketed cryogenic piping systems,冷冻低温管道系统 3. piping systems installed in a cold box in which the atmosphere is purged with an inert gas, 用惰性气体吹扫绝缘护套的管道系统 4. piping systems in which the temperature being maintained is sufficiently low or sufficiently high to preclude the presence of water. 温度保持足够低或足够高以阻止液态水的存在管道系统

充分保护免受外部腐蚀的管道系统

23) Certain areas and types of piping systems are potentially more susceptible to corrosion under insulation. Which of the items listed is not susceptible to CUI? a) Areas exposed to mist over-spray from cooling water towers. b) Carbon steel piping systems that normally operate in-service above 250 degrees but are in intermittent service. c) Deadlegs and attachments that protrude from insulated piping and operate at a different temperature than the temperature of the active line. d) Carbon steel piping systems, operating between 250 degrees F and 600 degrees F. 22) What climatic area may require a very active program for corrosion under insulation? a) b) c) d)

Cooler northern continent locations. Cooler direr, mid-continent locations Warmer, marine locations Warmer drier, desert locations

21) What are the most common forms of corrosion under insulation (CUI). a) Localised corrosion of non-ferrous metals and chloride stress corrosion cracking of carbon steel. b) Localised corrosion of chrome-moly steel and chloride stress corrosion cracking of ferritic stainless steel. c) Localised corrosion of carbon steel and chloride stress corrosion cracking of austenitic stainless steel d) Localised corrosion of nickel-silicon alloy and caustic stress corrosion of austenitic stainless steel 24) What location is subject to corrosion under insulation and inspection contributes to it? a) Locations where pipe hangers and other supports exist. b) Locations where insulator has been stripped to permit inspection of the piping. c) Locations where insulation plugs have been removed to permit piping thickness measurements. d) Locations where there is damaged or missing insulation jacketing.

6.5 Extent of Thickness Measurement Inspection 厚度测量检验范围

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厚度测量检查应获得足够有代表性的TML采样厚度读数, 应包括所有不同组件和方向(水平和垂直)数据.有效的厚度测量有助于策划将来的检验间隔与范围

6.6 Extent of Small-bore, Auxiliary Piping, and Threaded-connections Inspections. 小口径, 辅助管道, 螺纹连接检查范围

6.6.1 SBP Inspection 小口径检查范围小口径主要工艺管道主要工艺管道应按照本文件(同等主要工艺大管线) 要求的检查. 小口径次要工艺管道次要工艺管道有不同的最低要求，这取决于服务分类:  一类应按照主要工艺管道相同的要求检查。  二/三类为可选性。  经历或预期有潜在腐蚀的死角(列如:液位抑制器)应该策划检查.

API570, 3.1.72 primary process piping 主要管线 Process piping in normal, active service that cannot be valved off or, if it were valved off, would significantly affect unit operability. Primary process piping normally includes most process piping greater than NPS 2, and typically does not include small bore or auxiliary process piping (see also secondary process piping). 工艺管道正常,主流服务, 不能关闭阀或, 如果它被关闭阀，将显着影响单元可操作性。一般大于2寸口径管道。通常不包括小口径或辅助工艺管道

API570, 3.1.85 secondary process piping 次要管线 Process piping, often SBP downstream of block valves that can be closed without significantly affecting the process unit operability. 工艺管线通常为小口径管线,如隔断阀的下游,可以关闭而不会显着影响该单元过程的生产可操作性

Deadlegs with CMLs should be tracked in a separate piping circuit from the mainline piping. These deadlegs or low points are typically identified and documented in the inspection record by the inspector. Deadlegs may be combined into one circuit if their anticipated corrosion rates are similar. Inspections should include profile radiography on small diameter deadlegs, such as vents and drains, and UT or RT on larger diameter deadlegs. 死角应当作为独立于主流管线跟踪, 如果他们预期的腐蚀速率是相似的,死角可以组合成一个同一检验单元. 厚度测量探伤法有:  小口径管路可能需要剖面射线法,  大口径管路使用超声或射线探伤法.

6.6.2 Auxiliary Piping Inspection 辅助管道检验 Inspection of auxiliary SBP associated with instruments and machinery is optional and the need for which would typically be determined by risk assessment. Criteria to consider in determining whether auxiliary SBP will need some form of inspection include the following: 仪器及机械相关的辅助小口径管线检查是可选的, 如有需要检验,通常是通过风险评估来确定,考虑确定标准有： 1. classification,分类 2. potential for environmental or fatigue cracking, 潜在的环境或疲劳开裂 3. potential for corrosion based on experience with adjacent primary systems, 与相邻的主系统经验的基础上考虑潜在的腐蚀性, 4. potential for CUI. 保温层腐蚀

6.6.3 Threaded-connections Inspection 螺纹连接检验 Inspection of threaded connections will be according to the requirements listed above for small-bore and auxiliary piping. When selecting CMLs on threaded connections, include only those that can be radiographed during scheduled inspections. 小口径和辅助管道检验要求适用于带螺纹连接检验. CML位置选择: 仅包括那些可以在预定的检查时运用射线探伤的位置. 可能会因机械或疲劳导致损伤的螺纹连接,应 (1) 定期评估和考虑 (2)用较厚的壁代替或 (3) 升级到焊接构件.

6.7 Inspection and Maintenance of Pressurerelieving Devices (PRDs) 泄压装置的检查和维护

6.7.1 General 总则 PRDs shall be tested and repaired by a repair organization experienced in relief valve maintenance. PRDs should be inspected, tested, and maintained in accordance with API 576 泄压装置应当由有维修经验的维修机构按照API 576测试和修复

6.7.2 Quality Assurance Process for PRDs 质量保证过程 Each equipment repair organization shall have a fully documented quality assurance system. As a minimum, the following shall be included in the quality assurance manual: 设备维修机构应具有充分质量保证体系. Each repair organization shall also have a fully documented training program that shall ensure that repair personnel are qualified within the scope of the repairs. 设备维修机构应具有充分质量保证体系.也有完善的培训计划,确保维修人员在合格资质范围内进行相关维修校准.

6.7.3 PRD Testing and Inspection Intervals 测试和检验的时间间隔 6.7.3.1 General Pressure-relieving devices shall be tested and inspected at intervals that are frequent enough to verify that the valves perform reliably in the particular service conditions. 测试和检查的时间间隔足够确保能在特定服务的条件下可靠地运行. 6.7.3.2 Unless documented experience and/or an RBI assessment indicates that a longer interval is acceptable, test and inspection intervals for pressure-relieving devices in typical process services should not exceed: 除非考虑经验证明/或RBI评估要求,一般检验间隔不大于:  five years for typical process services, 典型的流程服务-5年  ten years for clean (non-fouling) and noncorrosive services. 清洁和非腐蚀性的服务-10年

82)All process piping systems must be categorised into different classes. On what are the classifications selection based? a) b) c) d)

Requirements of jurisdiction and the proximity of population areas Potential safety and environmental effects should a leak occur Liability to the owner-user and the requirements of the jurisdiction Access to the systems for inspection and closeness to population areas

83)Listed below are several examples of a CLASS 1 piping system. Which one does not belong? a) b) c) d)

Anhydrous hydrogen chloride; Hydrofluoric acid Piping over or adjacent to water and piping over public throughways Distillate and product lines to and from storage and loading

84)Of the three classification of piping systems, which includes the majority of unit processes and selected off-site piping? a) b) c) d)

Class 3 Combination of classes 1 and 2 Class 1 Class 2

85)Class 3 piping is described as being in services: a) With the highest potential of resulting in an immediate emergency if a leak occurs. b) That are flammable but do not significantly vaporise when they leak and are not located in high-activity areas c) That are not flammable and pose no significant risk to populated areas d) That are not in classes 1 and 2.

85)Class 3 piping is described as being in services: a) With the highest potential of resulting in an immediate emergency if a leak occurs. b) That are flammable but do not significantly vaporize when they leak and are not located in high-activity areas c) That are not flammable and pose no significant risk to populated areas d) That are not in classes 1 and 2. 86)Who establishes inspection interval for thickness measurements, external visual inspections and for internal and supplemental inspections? a) b) c) d)

Piping engineer Owner-user or the inspector Chemical Engineer Piping engineer and the jurisdiction

87)Thickness measurement inspection should be scheduled based on the calculation of not more than a) One half the remaining life determined from corrosion rates or the maximum interval of 5 years whichever is shorter. b) One half the remaining life determined from corrosion rates or the maximum interval allowed by API 570 in Table 1, whichever is shorter c) One fourth the remaining life determined from corrosion rates or the maximum interval of 10 years whichever is shorter. d) One quarter the remaining life determined from corrosion rates or the maximum interval allowed by API 570 in Table 1, whichever is shorter. 88)For external inspections for potential corrosion under insulation (CUI) on Class 1 systems, the examination should include at least __________ percent of all suspect areas and __________ percent of all areas of damaged insulation. a) b) c) d)

50, 75 50, 33 75, 50 25, 10

89)Piping systems that are known to have a remaining life of over __________ years or that are protected against external corrosion need not have insulation removed for the periodic external inspection. (2013 June) a) b) c) d)

10 15 5 20

90)For Class 3 piping systems, the examination for corrosion under insulation (CUI) should include at least __________ percent of all suspect areas. a) b) c) d)

50 30 10 0

91)For Class 2 piping, the extent of CUI inspections on a system operating at – 45oF will be: a) b) c) d)

75% of damaged areas, 50% of suspect areas 50% of suspect areas, 33% of damaged areas 33% of damaged areas, 50% of suspect areas None of the above

92)Small bore piping (SBP) that is Class I shall be inspected (2013 June) a) b) c) d)

Where corrosion has been experienced At the option of the inspector To the same requirements as primary process piping Only if it has dead legs

94)If an inspector finds threaded small bore piping (SBP) associated with machinery and subject to fatigue damage, he should: (2013 June) a) Plan periodically to assess it and consider it for possible renewal with a thicker wall or upgrade it to welded components. b) Inspect it only if it is corroded and the class of service requires an inspection. c) Call for dismantling the threaded joints for close inspection to determine if any cracks are in the roots of the threads. d) Have all the threaded piping renewed at each inspection period. 93)Inspection of small bore piping (SBP) that is secondary and auxiliary (associated with instruments and machinery) is a) b) c) d)

Only required where corrosion has been experienced Optional Only if it has dead legs Only if it is threaded

Sec~7 7 Inspection Data Evaluation, Analysis, and Recording 检验数据评估, 分析和记录

7 Inspection Data Evaluation, Analysis, and Recording 7.1 Corrosion Rate Determination 7.2 MAWP Determination 7.3 Required Thickness Determination 7.4 Assessment of Inspection Findings 7.5 Piping Stress Analysis 7.6 Reporting and Records for Piping System Inspection 7.7 Inspection Recommendations for Repair or Replacement 7.8 Inspection Records for External Inspections 7.9 Piping Failure and Leak Reports 7.10 Inspection Deferral or Interval Revision


7.1 Corrosion Rate Determination 腐蚀速率测定

7.1.1 Remaining Life Calculations 剩余寿命的计算 The remaining life of the piping system shall be calculated from the following formula:

7.1.2 Newly Installed Piping Systems or Changes in Service 新安装的管路系统或更改服务以下为新安装的管路系统或更改服务时用来重新计算腐蚀率, 优先考虑秩序; 1. 相同的工艺流程服务,操作条件,类似的材料的数据做为参考, 2. 用户的体验或从相同管道系统公布的数据做为参考, 3. 三个月的服务后,通过使用厚度测量测定无损厚度测量做为参考.


7.1.3 Existing Piping Systems Corrosion rates shall be calculated on either a short-term or a LT basis. 腐蚀速率应在短期或长期基础上的计算

计算 MAWP时,运用长期或短期腐蚀速率较大值 If calculations indicate that an inaccurate rate of corrosion has been assumed, the rate to be used for the next period shall be adjusted to agree with the actual rate found. 如果在计算腐蚀率是发现,前先的假设/计算是错误时,应当更改至真确的腐蚀率. (考试题)

7.2 MAWP Determination The MAWP for the continued use of piping systems shall be established using the applicable code. MAWP 计算应当按照所选的设计规范. 在这些计算中所用的残余厚度; 是实际通过检查确定厚度管壁厚度减(-)去两倍的下一个检验日期估计腐蚀损失. TMAWP = T实际 - 2 x 估计腐蚀损失估计腐蚀损失 = (LT或ST) x 检验间隔(法定或规范允许间隔). 小编: 两倍的估计腐蚀损失,可视为设定MAWP的安全系数.

For unknown materials, computations may be made assuming the lowest grade material and joint efficiency in the applicable code. 计算时用设计规范里材料最低档次的材料屈服/强度和焊缝效率.

7.3 Required Thickness Determination所需壁厚厚度确定 The required thickness of a pipe shall be the greater of the pressure design thickness or the structural minimum thickness. 管线设计厚度是取两者的较大值: (1) 压力设计厚度或 (2) 结构的最小厚度.

PMAWP = 计算 MAWP 时, 运用长期或短期腐蚀速率较大值

小编: 腐蚀量-C  最终腐蚀遗留量(c)  作业腐蚀量 (CR x Yrs) 腐蚀率 x 检验间隔(使用时间)  计算用作业腐蚀量 2x(CR x Yrs), 对腐蚀率估算不确定性的两倍的安全系数

上述的C腐蚀余留量, 也许是管壁的内壁(工艺腐蚀),外壁(外部环境腐蚀)双腐蚀. 计算时应当减去 C1 与 C2 (2013 June 考卷)

Question: A seamless NPS 10 pipe, ASTM A106 Grade B material operates at 750 psi and 700 degrees F (maximum). The thickness of the pipe as determined by the last inspection is 0.30". The pipe has been in service for 10 years. The original thickness (measured when installed) was 0.365". Two years previous to the 0.30" measurement the thickness of the pipe was measured to be 0.365". Two years previous to the 0.30" measurement the thickness of the pipe was measured to be 0.31". The next planned inspection is scheduled for 7 years. Using the worst corrosion rate (short or long term) determine what pressure the pipe will withstand at the end of its next inspection period?

Question: A blank is required between two NPS 10, 300 lb. class flanges. The maximum pressure in the system is 385 psi at 200 degrees F. A corrosion allowance of 0.175" is required. The inside diameter of the gasket surface is 9.25". The blank is ASTM A516 Grade 70 material with no weld joint. Calculate the pressure design thickness required for the blank.

For services with high risk, the piping engineer should consider increasing the required thickness to provide for unanticipated or unknown loadings, or undiscovered metal loss. 对于高风险的服务, 管道工程师应考虑增加所需的厚度

7.4 Assessment of Inspection Findings 评估检查结果 Pressure containing components found to have degradation that could affect their load carrying capability [pressure loads and other applicable loads (e.g. weight, wind, etc., per API 579-1/ASME FFS-1)] shall be evaluated for continued service. 当压部件发现有可能影响部件承载能力的退化时, 必须评估其持续服务达标的合适性. 评估方法有; 合适性评估

API 579-1/ASME FFS-1

API 579-1/ASME FFS-1

Assessment requires the use of a future corrosion allowance  Assessment of General Metal Loss—API 579-1/ASME FFS-1, Section 4.  Assessment of Local Metal Loss—API 579-1/ASME FFS-1, Section 5.  Assessment of Pitting Corrosion—API 579-1/ASME FFS-1, Section 6. In some cases will require the use of a future corrosion Allowance  Assessment of blisters and laminations-API 579-1/ASME FFS-1, Section 7 Assessment not requires the use of a future corrosion allowance  Assessment of weld misalignment and shell distortions- API 579-1/ASME FFS-1, Section 8.  Assessment of crack-like flaws- API 579-1/ASME FFS-1, Section 9.  Assessment of effects of fire damage-API 579-1/ASME FFS-1, Section 11.

7.5 Piping Stress Analysis 管道应力分析 Piping shall be supported and guided so that: 管道支撑和引导 1. its weight is carried safely, 安全足够的承载管道重量, 2. it has sufficient flexibility for thermal expansion or contraction 热膨胀收缩的灵活性, 3. it does not vibrate excessively.防范过度振动. 管道应力分析是早管系新建时的工程分析项, 在生产阶段多作为管系检验项,当检验员观察到过度的振动与承载问题时,应当及时的咨询管线工程师意见与考虑重新对受影响的管道做应力分析.

7.6 Reporting and Records for Piping System Inspection 管道系统检查的报告和记录 7.6.1 Permanent and Progressive Records 永久和逐行记录. 管道系统的所有者和使用者应当保持长期和逐行管路系统和泄压装置的记录. 7.6.2 Types of Piping Records 管道纪录类型    

新制造,施工和设计信息检验历史,记录维修, 改造和重新评级信息 FFS 评估文件要求

7.6.3 7.6.4 7.6.5 7.6.6

操作及保养记录-生产运作和维护记录计算机记录-便于检索,计算 MAWP,最低厚度等管道单元(circuit)记录-详细记录材料,工艺参数, 维修记录等等检查ISO图-确保检验重复性,等级分类,维修变动部位等等.

7.7 Inspection Recommendations for Repair or Replacement 检查建议维修或更换维修或更换建议列表应当及时更新,建议列表跟踪系统应包括: 1. Recommended corrective action or repair and date, 建议纠正措施或维修和日期 2. Priority or target date for recommended action, 优先级或建议的行动目标日期 3. Piping system identifier (e.g. piping system or circuit number) that the recommendation affects. 管道系统标识符 A management system is required for tracking and reviewing outstanding recommendations on a periodic basis.需要一个管理制度, 用于跟踪和定期审查尚未落实的建议.

7.8 Inspection Records for External Inspections 外部检查检测记录 Results of external piping system inspections shall be documented. 7.9 Piping Failure and Leak Reports 管道故障和泄漏报告 Leaks and failures in piping that occur as a result of corrosion, cracking or mechanical damage shall be reported and recorded to the owner-user

7.10 Inspection Deferral or Interval Revision 检查延迟或间隔修订没有既定的时间间隔内检查被认为是逾期查阅,除非 (1) 正式启动“延期检讨” 建立可接受的替代检验计划或 (2) 经过适当的分析修改检验间隔检查延迟延长的检查日期是根据成文的风险分析过程成立,是一次性, 临时管道检验到期日期延长,不应被视为检查间隔调整. 间隔修订当管道条件和历史审查表明过于保守或不足, 检查间隔可以适当修订, 延长或缩短.

API

Practice Problems # 1 1. Find the Maximum Allowable Working Pressure of a section of inservice piping. P = MAWP ? S = Maximum Allowable Stress 11,200psi t = Minimum thickness of pipe .245 inch E = Efficiency of longitudinal joint 80% D = Outside Diameter 6 inch P 　 2SEt/D

2. The thickness measured during the inspection of a section of pipe is .3875”. The pipe specification indicates that the pipe was originally 8” schedule 80 and the original nominal thickness was 0.5”. What is the long term corrosion rate if the pipe has been in service for 14 years?

3. The Owner/User orders a piping system that must carry 650 psi at 300ºF (temperature coefficient “Y”=.4), and the pipe must be 14” nominal pipe size. The stress of the ferritic material is 13,800 psi. The piping system will be operated in a slightly corrosive atmosphere and requires a 1/16” corrosion allowance. What is the minimum required thickness of this piping system with an efficiency of 100%?

4. If the diameter of a flange is 15.75”, what is the circumference? 5. If the base of a right triangle is 5 feet, and height is 7 feet, what is the length of the hypotenuse?

6. If P = 1500, E = .85, S = 13,500, Y = .4, and D = 28: find (t) in the following formula.

7. If the design pressure (P) of a piping system is 480psi and a pressure test of 1-½ times design pressure is to be applied, what would the test pressure (Pt) be if the stress at test temperature (St) is 13,800 psi and the stress at design temperature (S) is 8,400 psi?

9. A 4 inch test specimen is measured after a tensile test, and it is found that the length is now 4.575 inches. What is the percentage of elongation?

1. A section of piping, 38 feet long between the blank flanges, has been repaired and is ready for hydro, what is the volume, in cubic inches, of this piping section if the outside diameter is 8.625 inches and the thickness is .322 inches? 2. The piping engineer has determined that a fillet welded patch can be temporarily applied to the outside of an NPS 18 section of piping. The patch will be .5” thick and will be attached using a ½” leg length fillet weld. What would the theoretical throat of this fillet weld be? Throat .707Wleg 3. What is the total outside surface of a section of piping, requiring insulation, if the pipe is 32” outside diameter and 65 feet long?

4. A piping system was installed in 1954. The actual thickness at the time of installation was .7385”. The system had no thickness measurements taken until 1995, at which time the measured thickness was .603”. What is the resulting long term corrosion rate for this condition?

5. A newly constructed piping system is to be hydrostatically tested prior to being placed into service. The nominal thickness of the piping used in the system is .844”. The material stress value is 8500 psi at design temperature with quality factor of 1. The temperature coefficient (Y) is .4 and the outside diameter of the seamless piping is 10.75”. What is the required hydrostatic test pressure if the stress at test temperature equals 17,000psi? Use:

95) An eight-inch diameter piping system is installed in December 1979. The installed thickness if measured as 0.34". The minimum thickness of the pipe is 0.20". It is inspected 12/83 and the thickness is found to be 0.32". An inspection 12/87 reveals a loss of 0.01" from the 12/85 inspection. During 12/89 the thickness was found to be 0.29". The last inspection was during 12/95 and the thickness was found to be 0.26". What is the long-term corrosion rate of this system? a) b) c) d)

0.005”/year 0.0075”/year 0.00375”/year 0.0025”/year

96) Using the information in question 95, calculate the short-term corrosion rate: a) b) c) d)


97)Using the information in questions 95 and 96, determine the remaining life of the system: a) b) c) d)

18 years 15 years 12 years 6 years

98)You have a new piping system that has just been installed. It is completely new and no information exists to establish a corrosion rate. Also, information is no available on a similar system. You decide to put the system in service and NDT it later to determine the corrosion rate. How long do you allow the system to stay in service before you take your first thickness readings? (2013 June) a) b) c) d)

1 month 3 months 6 months 12 months

99)After an inspection interval is completed and if calculations indicate that an inaccurate rate of corrosion has been assumed in a piping system, how do you determine the corrosion rate for the next inspection period? (2013 June) a) Check the original calculations to find out what the error is in the original assumption. b) Unless the corrosion rate is higher, the initial rates shall be used. c) The corrosion rate shall be adjusted to agree with the actual rate found. d) If the corrosion rate is higher than originally assumed, call in a corrosion specialist.

100)If a piping system is made up of unknown materials and computations must be made to determine the minimum thickness of the pipe, what can the inspector or the piping engineer do t establish the minimum thickness? (2013 June) a) The lowest grade material and joint efficiency in the applicable code may be assumed for calculations. b) Samples must be taken from the piping and testing for maximum tensile stress and yield strength will determine the allowable stress to be used. c) The piping made of the unknown material must be removed from service and current piping of known material must be installed. d) The piping of unknown material may be subjected to a hydrostatic stress tests while having strain gages on it to determine its yield strength and thus allowable stress.

101)A piping engineer is designing a piping service with high potential consequences if a failure occurs, i.e., a 350 psi natural gas line adjacent to a high density population area. What should he consider doing for unanticipated situations? a) b) c) d)

Have all his calculations checked twice. Increase the required minimum thickness. Notify the owner-user and the jurisdiction. Set up an emergency evacuation procedure.

102)When evaluating locally thinned areas, the surface of the weld includes __________ on either side of the weld or __________ times the minimum measured thickness on either side of the weld, whichever is greater. a) b) c) d)

0.5”, 3 1”, 2 2”, 1 1.5”, 1.5

102) When evaluating locally thinned areas, the surface of the weld includes __________ on either side of the weld or __________ times the minimum measured thickness on either side of the weld, whichever is greater. a) b) c) d)

0.5”, 3 1”, 2 2”, 1 1.5”, 1.5

这题个根据?

103)An inspector finds a thin area in a fabricated 24" diameter pipe. The thin area includes a longitudinal weld in the pipe and is 10 feet long and 2 foot circumferentially. Calculations show that with 0.85 joint factor, the pipe must be repaired, renewed, etc. or the pressure in the pipe must be lowered. The owner does not want to do any hot work on the pipe and he does not wish to lower the pressure. What other course could you follow? a) Write the results of the inspection up and leave it with the owner. b) Radiograph the weld 100 % and increase the joint factor to one. c) Insist that the weld be repaired or renewed or that the pressure be lowered. d) Call in a regulator agency to force the owner to repair, renew, etc. the line.

104)Piping stress analysis is done during the system's original design. How can the inspector make use of stress analysis information? a) An inspector cannot use this information. It is only meaningful to a piping engineer. b) It can be used to make sure the piping system was originally evaluated and designed correctly. c) It can be used to concentrate inspection efforts at locations most prone to fatigue or creep damage, and to solve vibration problems. d) The inspector should use this information to evaluate the need for conducting additional piping stress analysis.

105) You are inspecting a piping system. You find a significant loss of material (a major increase of corrosion rate) in gas oil piping (used as reboiler oil, temperature 500°F) on a Fluid Catalytic Cracking Unit. What is the best course of action for you to take? a) The losses may be reported to your supervisor for corrective response b) The losses should be recorded and reported in your final report after the unit has started. c) It shall be reported to the owner-user for appropriate action. d) Replace excessively thin piping and note replacement in the final report after unit start-up.

106)The __________ shall maintain appropriate permanent and progressive records of each piping system covered by API 570. a) b) c) d)

Inspector Owner-user Jurisdiction Examiner

8) A NPS 6 piping system is installed in December 1989. The installed thickness is measured at 0.719”. The minimum thickness of the pipe is 0.456”. It is inspected in December 1994 and the measured thickness is 0.608”. An inspection in December 1995 reveals a 0.025" loss from the December 1994 inspection. During December 1996, the thickness was measured to be 0.571". What is the long-term corrosion rate of this system? a) b) c) d)


9) Using the data in Question No. 8, calculate the short term corrosion rate in mils per year (M/P year) a) b) c) d)

0.0012 M/P year 0.012 M/P year 0.12 M/P year 12 M/P year

10)Using the information in Questions No. 8 and No. 9, determine the remaining life of the system a) b) c) d)

18 years 5.44 years 1.2 years 6 years

11)Using the information in Questions No. 10 and assuming an injection point in a Class 2 system with 7 years estimated until the next inspection what would the next interval be: a) b) c) d)

10 years 5 years 3 years 2.72 years

7.1.1 Remaining Life Calculations Corrosion Rate 腐蚀率

LT and ST corrosion rates should be compared to see which results in the shortest remaining life as part of the data assessment. The authorized inspector, in consultation with a corrosion specialist, shall select the corrosion rate that best reflects the current process (1) 长期/短期腐蚀率以最大值作为剩余使用寿命计算或 (2) 授权检验员和管道工程师质询后,能反映现况最合适的腐蚀率

CR 腐蚀率用来干啥啊! a) 计算剩余使用寿命 b) 在职管道最高允许工作压力 ( c) 厚度检测最大计算时间间隔 (a/2)

在计算(b)最高允许压力, 或 (c) 厚度检验最大时间间隔时, API570 运用半衰期计算法作为安全系数:

API570, 6..3.3 Thickness measurements should be scheduled at intervals that do not exceed the lesser of one half the remaining life determined from corrosion rates indicated in 7.1.1.1 or the maximum intervals recommended in Table 2. Shorter intervals may be appropriate under certain circumstances. Prior to using Table 2, corrosion rates shall be calculated in accordance with 7.1.1.1. 7.1.1 Remaining Life Calculations The remaining life of the piping system shall be calculated from the following formula:

Table 2

在计算”剩余使用寿命”时半衰期检验法不需要考虑腐蚀率是,短期或长期腐蚀率较高值

服役压力管道厚度测量应在预定的时间间隔执行:(以下较小值)  Table 2 厚度检查间隔  一半的剩余寿命确定腐蚀速率

计算MAWP

CR 为长期/短期腐蚀率较大值 YRS 为下次检验时间间隔计算厚度为: 实际厚度(t) – 2xCRxYRS 下次检验时间间隔为剩余使用寿命的一半或Table2(较小值)

Table 4—Two Examples of the Calculation of MAWP Illustrating the Use of the Corrosion Half-life Concept

13)A seamless NPS 16 pipe, ASTM A135 Grade A material operates at 550 psi and 600 degrees F maximum. The thickness of the pipe as determined by the last inspection is 0.40". The pipe has been in service for 8 years. The original thickness at installation was measured to be 0.844". Two years previous to the 0.40" measurement the thickness of the pipe was found to be 0.54". Determine the greatest corrosion rate, i.e., short or long term in mils per year (M/P year). a) b) c) d)

55 M/P year 70 M/P year 0.70 M/P year 700 M/P year

0 years t= 0.844 6 years t= 0.54 8 years t= 0.40 Cr long= (0.844-0.40)/8 = 0.0555”/yr Cr Short= (0.54-0.40)/2 = 0.07”/yr

14)A seamless NPS 12 pipe, ASTM A106 Grade B material operates at 750 psi and 700 degrees F maximum. The thickness of the pipe as determined by the last inspection is 0.305”. The pipe has been in service for 13 years. The original thickness at installation was measured to be 0.405". Two years previous to the 0.305” measurement the thickness of the pipe found to be 0.316”. The next planned inspection is scheduled for 8 years. Using the appropriate corrosion rate determine what MAWP the pipe will withstand at the end of the next inspection period a) b) c) d)

720 psi 476 psi 611 psi 550 psi

Cr long = (0.405-0.305)/13 = 0.0077”/yr Cr short = (0.316-0.305)/2 = 0.0055”/yr Use Cr long = 0.0077”/yr Next inspection= 8 years P = 2x16700x(0.305-2x0.0077x8) / 12.75 = 476# B31.3-2010

15)A seamless NPS 6, ASTM A106 Grade A pipe operates at 300 degrees F and 765 psi. The allowable stress is 16,000 psi. Using the Barlow equation, determine the required thickness for these conditions a) b) c) d)

0.446” 0.332” 0.231” 0.158”

t = PD/2SE = 765x6.625 / (2x16000) 16)A seamless NPS 6, ASTM A106 Grade A pipe operates at 300 degrees F and 741 psi. The allowable stress is 16,000 psi. The owner-user specified that the pipe must have 0.125" for corrosion allowance. Using the Barlow equation, determine the required thickness for these conditions a) b) c) d)

0.278” 0.195” 0.325” 0.392”

17)A NPS 4 Schedule 80 (0.337" wall) branch connection is welded into a NPS 6 Schedule 40 (0.280" wall). A 0.375" reinforcing pad is used around the branch connection. The fillet weld sizes are as required by the Code. The branch connection is inserted into the header. The material of the branch and header is ASTM A672 Grade B70. What thickness would be used to determine whether heat treatment of the connection is required? (Express answer to nearest hundredth.) a) b) c) d)

0.768” 0.891” 0.998” 0.567”

331.1.3 Governing Thickness. …In the case of branch connections, metal (other than weld metal) added as reinforcement, whether an integral part of a branch fitting or attached as a reinforcing pad or saddle, shall not be considered in determining heat treatment requirements. “ Heat treatment is required, however, when the thickness through the weld in any plane through the branch is greater than twice the minimum material thickness requiring heat treatment” even though the thickness of the components at the joint is less than the minimum thickness. Thickness through the weld for the details shown in Fig. 328.5.4D shall be computed using the following formulas:

17)A NPS 4 Schedule 80 (0.337" wall) branch connection is welded into a NPS 6 Schedule 40 (0.280" wall). A 0.375" reinforcing pad is used around the branch connection. The fillet weld sizes are as required by the Code. The branch connection is inserted into the header. The material of the branch and header is ASTM A672 Grade B70. What thickness would be used to determine whether heat treatment of the connection is required? (Express answer to nearest hundredth.) a) b) c) d)

0.768” 0.891” 0.998” 0.567”

Used sketch(2) = Th + Tc Answer ?

19)A seamless NPS 10 pipe, ASTM A106 Grade B material, operates at 750 psi and 700 degrees F (maximum). The thickness of the pipe as determined by the last inspection is 0.30". The pipe has been in service for 10 years. The original thickness (measured when installed) was 0.365". Two years previous to the 0.30" measurement the thickness of the pipe was measured to be 0.31". Determine the greatest corrosion rate i.e. short or long term a) b) c) d)

0.0050 inches per year 0.0065 inches per year 0.0100 inches per year 0.0130 inches per year

Cr long = (0.365-0.3) /10 = 0.0065”/yr Cr short = (0.31-0.3)/2 = 0.005”/yr

20)A seamless NPS 10 pipe, ASTM A106 Grade B material operates at 750 psi and 700 degrees F (maximum). The thickness of the pipe as determined by the last inspection is 0.30". The pipe has been in service for 10 years. The original thickness (measured when installed) was 0.365". Two years previous to he 0.30" measurement the thickness of the pipe was measured to be 0.31". The next planned inspection is scheduled for 7 years. Using the worst corrosion rate (short or long term) determine what pressure the pipe will withstand at the end of its next inspection period ? a) b) c) d)

920 psi 540 psi 811 psi 750 psi

CR long = (0.365-0.3)/10 = 0.0065”/yr CR short = (0.31-0.3)/2 = 0.005”/yr MAWP = 2x 13900(0.30-2x 0.0065 x7-c) / 10.75 = 540psi

Sec~8 8 Repairs, Alterations, and Rerating of Piping Systems 管道系统维修,改造及重新核定

8 Repairs, Alterations, and Re-rating of Piping Systems 8.1 Repairs and Alterations 8.2 Welding and Hot Tapping 8.3 Re-rating

8.1 Repairs and Alterations

8.1 Repairs and Alterations 维修和改建 8.1.1 General 大纲由于维修,改造阶段不同于新建, 原则上符合ASME B31.3要求, 而不是实际根据. 在不能满足ASME B31.3时,管道工程师或授权检验员应遵循API 570 指导来代替按照 ASME B31.3严格要求. The phrase “principles of ASME B31.3” has been employed in API 570, rather than “in accordance with ASME B31.3.”

8.1.2 Authorization 授权 1. 2. 3. 4.

所有维修及改建工程开始前应经检查员授权. 管道改造工作可能有必要事先咨询并通过管道工程师审批检查员可以指定任何检查点(包括停留点). 在对修护单位能力满意之下,一般例行维修及程序,授权检验员可事先给予有限的授权.

8.1.2 Authorization 授权 1. 2. 3. 4.

所有维修及改建工程开始前应经检查员授权. 管道改造工作可能有必要事先咨询并通过管道工程师审批检查员可以指定任何检查点(包括停留点). 在对修护单位能力满意之下,一般例行维修及程序,授权检验员可事先给予有限的授权

109) Authorization for alteration work to a piping system may be given by the inspector after: a) b) c) d)

Notifying the jurisdiction and getting their approval Consulting API 570 and getting the approval of the owner-user Consultation with and approval by a piping engineer Discussing with and consent by an examiner

110) A repair procedure involving welding requires that the root pass of the weld be inspected before continuing the weld. A "hold" on the repair is required at this point. Who designates this "hold?“ a) b) c) d)

A metallurgist The owner-user An API 570 inspector The welder supervisor

111)What type of repairs and procedures may the inspector give prior general authorization to continue (provided the inspector is satisfied with the competency of the repair organization)? a) b) c) d)

Major repairs and minor procedures Limited or routine repairs and procedures Alterations and re-ratings Minor re-ratings and alterations

112)Who approves all proposed methods of design, execution, materials, welding procedures, examination and testing of in-service piping? a) b) c) d)

The jurisdiction or the piping engineer as appropriate The analyst and the operator as appropriate The examiner and the piping programmer as appropriate The inspector or the piping engineer as appropriate

8.1.3 Approval 正式批准  所有管道维修, 改造建议的方法,应得到授权检验员或管道工程师审批.  运转管道,在线焊接必须的到业主/用户批准.

运转管道, 在线焊接必须的到业主/用户批准

运转管道, 在线焊接必须的到业主/用户批准

8.1.4 Welding Repairs (Including On-stream) 焊接维修(包括运转中管线） 8.1.4.1 Temporary Repairs 临时修理管道工程师设计一个分割两半焊接全面包围圈套筒或箱式外壳可施加在损坏或腐蚀的区域.临时外壳和维修的设计应管道工程师批准. 纵裂纹不能以这种方式进行修复, 除非管道工程师已确定,纵裂纹不会在围圈套筒延伸. 在有些情况, 管线工程师有必要咨询断裂分析师

如果局部维修(例如;点蚀或针孔状) 可以运用半圆扣板或钢板,角焊方式罩盖修复部位. 上述修护方法的前提为;  SMYS < 40 000psi (275 MPa) 最小屈服强度  API Standard 579-1/ASME FFS-1-通过适用性评价作业要求:  修复版尺寸不能大于管半径  两个修复最小距离间隔为 √(Dt)

纵裂纹不能以这种方式进行修复(半圆弧板或钢板-角焊), 除非管道工程师已确定,纵裂纹不会在围圈套筒延伸

All repair and welding procedures for on-stream lines shall conform to API 2201. 运转管道焊接维修应当符合 API 2201要求

分割连接器或补修板的修补运用前提要求满足SMYS/FFS 两项要求

Annex C (informative) Examples of RepairsC.1 Repairs 修补

GMAW / SMAW 焊接方法: 当室温小于10oC,焊接ASTM A-53, Grades A and B; A-106, Grades A and B; A-333; A-334; API 5L钢材或等同焊材时应当使用低氢焊条(AWS EXX16 or E-XX18) 在焊接其他低级碳钢材料(在询问工程师下使用) :  如果使用低氢焊条,焊接时母材温度可以低至0oC. 焊接方法:  垂直焊缝-C2,C3 焊接方向应Vertical-up 垂直向上 / 焊条直径≤ 4mm /  横向焊接-C1 焊条≤4.8mm / 焊缝应当有根部衬背. 如受修复的管道已彻底用超声波的方法检查和具有足够的承受焊接焊弧厚度衬板可以免除.

Used ≤Φ4.8mm, Low Hydrogen electrode.

≤Φ4.8mm, with backing strip.

8.1.4.2 Permanent Repairs 永久修复如有缺陷, 可以把缺陷完全去除, 按照 8.2 以焊接填充形成的沟槽. 插入修复板可用于修复损坏或腐蚀的区域，如果满足以下要求：  全熔透坡口焊缝  一类与二类管道修复焊缝必须 100% 射线探伤或超声波测试  修护板可以以任何形状,必须拥有一寸(25mm)半径圆角 . ASME PCC- 2 焊接修理管道系统的更多信息

8.1.5 Non-welding Repairs (On-stream) 非焊修复局部减薄部分或圆周线缺陷临时修理,可能通过安装适当的设计和应用非焊外壳(例如螺栓钳,非金属复合管套,金属和环氧树脂包裹,或其他非焊接的临时修理) 检修期间或其他适当的机会,采取适当的行动把临时修复复原,以恢复原始的完整的管路系统

8.2 Welding and Hot Tapping 焊接, 热连接

8.2.1 General 所有维修及改装焊接应按照ASME B31.3的原则来进行. 运转管道焊接, 热连接应参考 API 2201 进行. 8.2.2 Procedures, Qualifications, and Records 程序,评定与记录所有维修及改装焊接应按照ASME B31.3的原则来进行. 焊接工艺,焊工资质应当按照ASME B31.3要求.


8.2.3 Preheating and PWHT预热和焊后热处理 8.2.3.1 General 参照API 577指导预热和焊后热处理. 8.2.3.2 Preheating 预热温度用于焊接维修应按照适用的规范的合格的焊接工艺. 临时修理,可以经过管道工程师审批例外. 改装或修理管道系统时预热不低于300oF(150oC)可能被视为替代新建管线焊接规范焊后热处理要求. 预热不可能用于防止环境开裂

预热不可能用于防止环境开裂. 当使用的预热的替代焊后热处理要求时,需要和管道工程师协商,考虑 (1) 潜在的环境开裂和 (2) 足够的焊后韧性..

8.2.3.3 PWHT 焊后热处理焊后热处理应使用管道系统的维修或改装的适用要求如ASME 参考 8.2.2.2 预热作为代替焊后热处理的指导. 局部焊后热处理取代 360o 全面围绕热处理,以下要求应当符合:    

程序经管道工程师开发并得到审核通过, 充分考虑材料,焊接与应力等因素前期焊接,焊接预热温度至少150oC / (全程) 焊接时保持此温度. 局部焊后热处理覆盖面至不小于两倍管道厚度,按照管道厚度,形状合理安装至少两个或更多热电偶  热处理受处理区域,受热范围应包含;任何管道分支连接或其它附件,  遵照规范执行,而不是耐环境开裂为目标.

8.2.4 Design 设计对接接头应为全熔透坡口焊缝. 8.2.5 Materials 母材在维修或改建所用的材料是质量符合适用的规范已知的,可焊接的材质. 8.2.6 NDE 焊接修护或改装的无损探伤要求验收应按照适用的规范和业主/用户的规格. 表面和内部缺陷NDE检查应按照ASME 锅炉和压力容器第五节 ASME BPVC Section V

8.2.7 Pressure Testing 压力试验经过改建和主要维修通常需要压力测试.参考ASME PCC-2 压力测试的更多信息.  当压力测试是没有必要或不实际,无损检测可以用来代替压力测试  无损检测用来代替压力测试必须得到授权检验员/管道工程师的咨询与同意. 当最终闭合焊缝不实际进行的压力试验时,损检测用来代替压力测试必须同时满足以下条件:  新的或替换的管道通过压力测试(或NDE代替)并按照适用的规范审查,设计,  封闭焊缝必须是全熔透对焊,例外为: Class 150(500oF) 能用滑动式法兰设计/ 承插焊法兰或承插焊活管接(Union)尺寸NPS 2或更少Class 150(500oF) .  最终关闭对焊应为100%RT或角度束超声波探伤,  MT或PT表面探测. 用户应当指明超声横波检验员必须拥有相关的工业超声横波探伤资质.

http://www.pipeliners-uk.com/photo3_10.html

http://www.pipeliners-uk.com/photo3_10.html

8.3 Re-rating 重新评级重新评级管道系统的通过改变(1) 温度等级或 (2) 最大允许工作压. 必须满足以下要求:    

通过管道工程师或授权检验员计算审核, 重新评价应当符合新建规范要求, 检查记录验证管道系统符合当前工艺,压力要求以及适当的腐蚀预留厚度, 重新评估系统是否应当按照新建规范做管道泄漏测试(除了不带来材料强度变化的温度更改不需要做管道泄漏测试),

     

泄压装置设置;适当的设定压力,并有相应的排泄能力, 重新评级,被授权检验员或管道工程师接受, 所有的管道系统中的组件符合压力,温度等级, 管道系统有足够的灵活性适应重新评级后的温度变化, 适当的工程记录更新, 实际的冲击试验证明(在规范要求下);最低工作温度达到规范韧性要求.

OPEN

107)When making repairs and alterations to piping systems, the principles of __________ or the code to which the piping system was built shall be followed: (2013 June) a) b) c) d)

ASME B31.3 API 570 API 574 ASME B&PV Code

108)Repair and alteration work must be done by a repair organisation as defined in API 570 and must be authorised by the __________ prior to its commencement: a) b) c) d)

Jurisdiction Inspector Owner-user Examiner

109)Authorisation for alteration work to a piping system may be given by the inspector after: a) b) c) d)

Notifying the jurisdiction and getting their approval Consulting API 570 and getting the approval of the owner-user Consultation with and approval by a piping engineer Discussing with and consent by an examiner

110)A repair procedure involving welding requires that the root pass of the weld be inspected before continuing the weld. A "hold" on the repair is required at this point. Who designates this "hold?“ a) b) c) d)

A metallurgist The owner-user An API 570 inspector The welder supervisor

111)What type of repairs and procedures may the inspector give prior general authorisation to continue (provided the inspector is satisfied with the competency of the repair organisaton)? a) b) c) d)

Major repairs and minor procedures Limited or routine repairs and procedures Alterations and re-ratings Minor re-ratings and alterations

112)Who approves all proposed methods of design, execution, materials, welding procedures, examination and testing of in-service piping? a) b) c) d)

The jurisdiction or the piping engineer as appropriate The analyst and the operator as appropriate The examiner and the piping programmer as appropriate The inspector or the piping engineer as appropriate

113) Who must give approval for any on-stream welding? a) b) c) d)

Owner-user Jurisdiction Examiner Analyst

114) An inspector finds a crack in the parent metal of a pipe adjacent to a support lug. The pipe was being inspected after a 5 year run. Before repairing, he should: (2013 June) a) Notify the jurisdiction prior to the start of any repairs b) Write a detailed procedure for the repair organisations use in repairing the crack c) Consult with the piping engineer to identify and correct the cause of the crack. d) Consult with a metallurgist prior to writing a procedure to repair the crack.

115) A full encirclement welded split sleeve designed by a piping engineer may be applied over a damaged or corroded area of a pipe. This is considered a temporary repair. When should a permanent repair be made? a) If the owner-user designates the welded split sleeve as permanent, it may remain. b) A full encirclement welded split sleeve is permanent if okayed by the inspector. c) A full encirclement welded split sleeve is considered a permanent repair. d) A permanent repair must be made at the next available maintenance opportunity.

116) What type of defect, corrosion, pitting and / or discontinuity should not be repaired by a full encirclement welded split sleeve? a) b) c) d)

A longitudinal crack A circumferential crack Pits that are one half through wall General corrosion in the longitudinal direction.

117) If a repair area is localised (for example, pitting or pin-holes) and the specified minimum yield strength (SMYS) of the pipe is not more than __________ psi, a temporary repair may be made by fillet welding a properly designed plate patch over the pitted area: a) b) c) d)

30,000 psi 55,000 psi 40,000 psi 36,000 psi

118) Insert patches (flush patches may be used to repair damaged or corroded areas of pipe if several requirements are met. One of these is that an insert patch (flush patch) may be of any shape but it shall have rounded corners with __________ minimum radii. a) b) c) d)

0.375" 0.50" 0.75" 1"

119)An inspector finds a pin-hole leak in a weld during an on-stream inspection of a piping system. A permissible temporary repair is :a) b) c) d)

The use of plastic steel to seal off the leak Driving a wooden plug into the hole Screwing a self tapping screw into the hole The installation of a properly designed and fabricated bolted leak clamp.

120)Temporary leak sealing and leak dissipating devices shall be removed and the pipe restored to original integrity: a) b) c) d)

As soon as the piping system can be safely removed from service At a turnaround or other appropriate time When the leak seal and leak dissipating device ceases to work As soon as possible – must be done on a safe, emergency shut-down basis

123)All repair and alteration welding to piping systems shall be done in accordance with the: a) built b) c) d)

Exact procedures of ASME B31.3 or to the code to which it was Standards of ASME B31.1 or the code to which it was built Principles of ASME B31.3 or the code to which it was built Ideals of ASME, NBIC, or API standards

124)Welders and welding procedures used in making piping repairs, etc. shall be qualified in accordance with: a) b) c) d)

ASME B31.3 or the code to which the piping was built NBIC or the system to which the piping was built NACE or the method to which the piping was built ASTM or the law to which the piping was built

125)The repair organisation responsible for welding shall maintain records of welding procedures and welder performance qualifications. These records shall be available to the inspector: a) b) c) d)

At the end of the job After the start of welding Following the start of welding Before the start of welding

126)Preheating to not less than __________ °F may be considered as an alternative to post weld heat treatment for alterations or repairs of P-1, piping initially post weld heat treated as a code requirement (may not be used if the piping was post weld heat treated due to environmental cracking prevention). a) b) c) d)

150 200 300 350

127)When using local PWHT as a substitute for 360-degree banding on local repairs of PWHT'd piping, which of the following items is NOT considered. a) The application is reviewed, and a procedure is developed by the piping engineer b) The locally PWHT'd area of the pipe must be RT'd or UT'd c) A preheat of 300oF or higher is maintained while welding d) The PWHT is performed for code compliance and not for environmental cracking 128)Piping butt joints shall be: a) b) c) d)

Double spiral fillet welds Single fillet lap welds Double fillet lap welds Full-penetration groove welds

129)When should piping components that need repair be replaced? a) b) c) d)

When enough time remains on a turnaround to allow replacement When repair is likely to be inadequate When the cost of repair is as high as renewal When replacement is preferred by maintenance personnel

130)Fillet welded patches (lap patches) shall be designed by a) b) c) d)

An engineer The inspector The piping engineer The repair organisation

131) Fillet welded lap patches (overlay patches) shall leave: a) b) c) d)

No membrane stresses Right-angle corners Rounded corners Burnished corners

132) Materials used in making welding repairs or alterations __________ be of known weldable quality: a) b) c) d)

May Shall Should Can

133)Acceptance of a welded repair or alteration shall include __________ in accordance with the applicable code and the owner-user's specification, unless otherwise specified in API 570. a) b) c) d)

Nominal Pragmatic Sizing (NPS) NBE Safeguards Nondestructive examination

134)After welding is completed on a repair or alteration, __________ in accordance with API 570 shall be performed if practical and deemed necessary by the inspector. a) b) c) d)

NPS Safety sanctions BE A pressure test

135)When are pressure tests normally required? a) b) c) d)

Pressure tests are normally required after alterations and any repair Pressure tests are normally required after alterations and major repairs Pressure tests are normally required after major and minor repairs Pressure tests are normally required only as specified by the owner-user

136)When a pressure test is not necessary or practical, what shall be utilised in lieu of a pressure test? a) b) c) d)

NPS Nondestructive examination Vacuum visual examination NBE

138) When it is not practical to perform a pressure test of a final closure weld that joins a new or replacement section of piping to an existing system, several requirements shall be satisfied. Which of the following is NOT one of the requirements? a) The closure weld is a full-penetration fillet weld between a weld neck flange and standard piping component or straight sections of pipe of equal diameter and thickness, axially aligned, and or equivalent materials. For design cases up to Class 150 and 500oF, slip-on flanges are acceptable alternates. b) MT or PT shall be performed on the root pass and the completed butt weld. Fillet welds must have PT / MT on the completed weld. c) The new or replacement piping is pressure tested. d) Any final closure butt weld shall be of 100 % radiographic quality; or angle-beam UT may be used, provide the appropriate acceptance criteria is established.

137)Special procedure in place of a pressure test after an alteration or repair may be done only after consultation with :a) b) c) d)

The operators and the repair organisation The inspector and the piping engineer The jurisdiction The examiner and the inspector

139)Which of the following is NOT a requirement for re-rating a piping system by changing the temperature or the MAWP: a) The existing pressure relieving devices are still in place and set as they were originally b) Calculations are performed by the piping engineer or the inspector c) Piping flexibility is adequate for design temperature changes d) A decrease in minimum operating temperature is justified by impact test results, if required by the applicable code.

178)When making a repair utilising a welded full encirclement repair sleeve and the sleeve material is different from the pipe material, you should: a) b) c) d)

Consult the piping engineer Use a weld rod matching the higher strength material Use a weld rod matching the lower strength material Use an alloy weld rod such as Inco-A

179)What type of electrode should be used when welding a full encirclement repair sleeve? a) b) c) d)

Low-hydrogen electrode Low-phosphorous electrode Low-chrome electrode Low-nitrogen electrode

C.1 Repairs Manual welding utilizing the gas metal-arc or shielded metal-arc processes may be used. When the temperature is below 50 °F (10 °C), low-hydrogen electrodes, AWS E-XX16 or E-XX18, shall be used when welding materials conforming to ASTM A-53, Grades A and B; A-106, Grades A and B; A-333; A-334; API 5L; and other similar material. These electrodes should also be used on lower grades of material when the temperature of the material is below 32 °F (0 °C). The piping engineer should be consulted for cases involving different materials.

180)Which of the following welding electrodes is low-hydrogen ? a) b) c) d)

E6010 E7016 E7011 E7014

181)When welding a small repair patch, the diameter of electrodes used should not exceed a) b) c) d)

1/8" 3/16" 5/32" 1/4"

Sec~9 9 Inspection of Buried Piping 埋地管道的检验

9 Inspection of Buried Piping 埋地管道的检验

9 Inspection of Buried Piping 9.1General 9.2 Types and Methods of Inspection 9.3 Frequency and Extent of Inspection 9.4 Repairs to Buried Piping Systems 9.5 Records

9.1 General 总则不同于其他工艺管道检验,因为土壤腐蚀性显着影响管道外部腐蚀和埋地也给外观检验带来困难. 非强制性地下管道检查的参考有  API 574- Inspection Practices for Piping System Components 管道系统部件的检查实践  API 651- Cathodic Protection of Aboveground Petroleum Storage Tanks 地上石油储罐阴极保护

•

•

•

NACE RP0169- Control of External Corrosion on Underground or Submerged Metallic Piping Systems 地下或水下金属管道系统外部腐蚀控制 NACE RP0274- High-voltage Electrical Inspection of Pipeline Coatings Prior to Installation 管道涂层高压电器检测 NACE RP0275- Application of Organic Coatings to the External Surface of Steel Pipe for Underground Service 地下服务钢管外表面有机涂料中的应用.

9.2 Types and Methods of Inspection 类型和检验方法

9.2.1 Above-grade Visual Surveillance 地面目视监控埋地管道泄漏可能包括地面的表面轮廓的变化, 对土壤变色,沥青软化摊铺,池形成,陷坑,鼓泡,或有明显的气味:地面目视监控能带来一些有用的信息.

沥青软化摊铺,池形成.

大连输油管道爆炸事故原因尚待调查:海洋污染影响水域100平方公里

9.2.2 Close-interval Potential Survey 密间隔管电位测量在地面进行的调查埋地管道电位测量能有效的定位管的表面上的腐蚀活跃点. 由于涂层管表面和腐蚀表面的电位差, 腐蚀位置能被测量出来.

http://www.rogeralexander1938.webspa ce.virginmedia.com/cpn/cips.htm

9.2.3 Pipe Coating Holiday Survey 管涂层漏电调查管涂层漏电调查能用来检测新建管线涂层质量,也能检测重新挖开的在职管线表面涂层的质量信息.从调查数据显示,涂料的有效性和涂料恶化率可确定.

9.2.4 Soil Resistivity 土壤电阻率土壤的腐蚀性是以土壤电阻率来确定, 土壤电阻率越低土壤腐蚀性越大, 特别是地埋管道接触显著不同土壤电阻率的区域. 有三种常用的方法确定电阻率;  温纳四针法(ASTM G57) Wenner Four-pin Soil Resistivity Test  土壤杆 Soil Bar Used for Soil Resistivity Measurements  土箱 Soil Boxes Used for Soil Resistivity Measurements

API574: Figure 30—Wenner Four-pin Soil Resistivity Test

API574: Figure 31—Soil Bar Used for Soil Resistivity Measurements

API574: Figure 32—Two Types of Soil Boxes Used for Soil Resistivity Measurements

9.2.5 Cathodic Protection Monitoring 阴极保护埋地管道应定期监测,以保证足够的保护水平,监测应包括定期 “管/地”(pipe to soil)电位差测量和分析. 参考: NACE RP0169 and Section 11 of API 651适用于埋地管道的阴极保护系统的检查和维护指导  API 651 Cathodic Protection of Aboveground Petroleum. Storage Tanks.  NACE RP0169- Control of External Corrosion on Underground or Submerged Metallic Piping Systems.


9.2.6 Inspection Methods 测定方法参考 API 574 更加详细描述检验方法以下是一些检验地埋管到外表与内部检验的方法：    

智能清管器检验方法摄像机挖掘外加筛查技术-LRUT/LRGUT

http://www.ndted.org/EducationResources/CommunityCollege/Ultrasonics/Equipm entTrans/ematlambwave.htm

9.3 Frequency and Extent of Inspection 检查的频率和范围

9.3.1 Above-grade Visual Surveillance 地面目视监控大约每隔6个月的调查 (看 9.2.1). 9.3.2 Pipe-to-soil Potential Survey 管/地电位差调查阴极保护线: 密间隔电位测量能有效的确认管道是否全面的保处于护电位.不良管道涂层导致不

均匀的电压差,这些管道应每五年进行测量,探测出的腐蚀热点并开挖检查外表腐蚀情况. 9.3.3 Pipe Coating Holiday Survey 管涂层漏电调查管涂层漏电调查通常是基于其他形式的腐蚀控制失效时,用来检测管道涂层的完

整性.

地面目视监控大约每隔 “6个月”的调查 (看 9.2.1). 管地电位调查不良涂层, 阴极保护不完善的管道, “5年”的时间间隔进行核查.

9.3.4 Soil Corrosivity 土壤腐蚀性对于非阴极保护,长度大于100英尺(30米)管道-每五年做土壤腐蚀性/土壤电阻率测量.

9.3.5 Cathodic Protection 如果管道阴极保护,该系统应监视的时间间隔,在根据第 NACE RP0169 Section 10 或 API 651. NACE RP0169-2002 “Standard Recommended Practice Control of External Corrosion on Underground or Submerged Metallic Piping Systems” 10.3 The effectiveness of the cathodic protection system should be monitored annually. Longer or shorter intervals for monitoring may be appropriate, depending on the variability of cathodic protection factors, safety considerations, and economics of monitoring.”

9.3.6 External and Internal Inspection Intervals 外部和内部检查间隔没有有效的阴极保护管道,运用内管检测器(pigging)或要定期(表-5)在一个或多个位置被认为是最易受腐蚀开挖目视检查. (开挖目视部位为6 ft to 8 ft /2.0 m to

2.5 m) .

9.3.4 Soil Corrosivity 土壤腐蚀性对于非阴极保护,长度大于100英尺(30米)管道-每五年做土壤腐蚀性/土壤电阻率测量.

9.3.7 Leak Testing Intervals 泄漏测试时间间隔替代或补充检查是执行泄漏试验,实验压力为110% MAWP. 时间间隔:  非管道阴极保护: Table 5 一半的时间间隔  管道阴极保护: Table 5 时间间隔

泄漏测试应保持 8小时:  前四小时: 初始加压四小时后,检查压力,如果有必要重新加压到原始试验压力,  后四小时: 隔离受压系统观察保压压力变动. 如保压压力降低 5％以上,执行目视外部和/或内部检查, 定位泄漏部位与评估腐蚀程度

9.4 Repairs to Buried Piping Systems 埋地管道系统的维修

9.4.1 Repairs to Coatings 涂层的维修涂层修复应符合下列条件： • • • • •

够的粘合力以防止的水分的渗透足够的延展性抵抗开裂涂层没有气孔, 漏点等缺陷足够的强度适用处理和土壤应力阴极保护合适性

使用高电压漏电检测器测试维修后涂层,电压必须调至合适被检测的涂层厚度.发现到的漏点进行标记,局部修复.(重新高压漏电检测)

9.4.2 Clamp Repairs 钳修复钳修复的位置应记录在检查记录,并可进行表面标.所有夹具修复应视为暂时的应在第一时间(机会)做永久修复.

9.4.3 Welded Repairs 焊接维修焊接维修应按照8.2.

9.5 Records 地管道的记录系统应按照7.6.档案.

140) Why is the inspector of buried process piping (not regulated by DOT) different from other process piping inspection ? a) The insulating effect of the soil increases the possibility of more internal combustion b) Internal corrosion has to be controlled by cathodic protection c) Significant external deterioration can be caused by corrosive soil conditions d) Internal corrosion must be controlled by internal coatings. 141) Indications of leaks in buried piping may include several indications. Which of the ones listed below is NOT one of the indications ? a) b) c) d)

A change in the surface contour of the ground. Water standing on the pipeline right-of-way Discoloration of the soil Notice odour

142) Corrosion cells can form on both bare and coated pipe where bare steel contacts the soil. How can these cells be detected ? a) Run an acoustic emission test on the piping b) Visually survey the route of buried piping c) The potential at the area of corrosion will be measurable different than other areas and a close-interval potential survey can detect the location of corrosion d) Run an internal survey of the piping using a video camera 143) A pipe coating holiday survey is used to locate coating defects on coated pipes. It can be used on newly constructed pipe systems to ensure that the coating is intact and holiday-free. More often, it is used on buried pipe to: a) Show the measurable differences in electrical potential in corroded areas b) Evaluate coating serviceability for buried piping that has been in-service for a long time. c) Determine the depth of the piping for resistivity testing d) Evaluate the cathodic protection components of the under-ground pipe

144) Cathodically protected buried piping should be monitored __________ to assure adequate levels of protection: a) b) c) d)

Regularly Intermittently Erratically Frequently

145) If an "intelligent pigging" system is used to inspect buried piping, what type of bends are usually required in the piping system ? a) b) c) d)

Five diameter bends 90 degree pipe ells Ten diameter bends Three diameter bends

146) How often should above-grade visual surveillance of a buried pipeline rightof-way be made? a) b) c) d)

Once a month Approximately 6 month intervals Once a year Once every 3 months

147) How often should poorly coated pipes with inconsistent cathodic protection potentials have a pipe-to-soil potential survey made ? a) b) c) d)

Yearly Every 2 years Every 5 years Every 7 years

148)On buried piping, what is the frequency of pipe coating holiday surveys? a) The frequency is governed by the leak test interval of the pipe b) It is usually based on indications that other forms of corrosion control are ineffective. c) Surveys are normally made every 5 years d) Pipe coating holiday surveys are made when the pipe is excavated. 149)For a piping buried in lengths greater than __________ feet and not cathodically protected, evaluation of soil corrosivity should be performed at 5-year intervals. a) b) c) d)

50 75 100 150

150)If buried piping is cathodically protected, the system should be monitored at intervals in accordance with Section 10 of NACE RP0169 or Section 90 of API RP 651. API RP 651 specifies __________ interval. a) b) c) d)

Annual Biannual Biennial Trennial

152) After excavation of buried piping, if inspection reveals damaged coating or corroded piping: a) The condition should be noted in the records and the inspection interval shortened b) The complete piping system must be day-lighted (excavated) for repair or replacement. c) The damaged coating or corroded piping must be repaired or replaced d) Additional piping shall be excavated until the extent of the condition is identified. 151) Buried piping inspected periodically by excavation shall be inspected in lengths of __________ feet at one or more locations judged to be most susceptible to corrosion a) b) c) d)

2 to 4 4 to 6 6 to 8 8 to 10

153)If buried piping is contained inside a casing pipe, the casing should be: a) b) c) d)

Capable of carrying the same pressure as the product pipe Checked to see if its protective coating is intact and serviceable Pressure tested to make sure it is serviceable Inspected to determine if water and / or soil has entered the casing

154)An alternative or supplement to inspection of buried piping is leak testing with liquid at a pressure at least __________ % greater than the maximum operating pressure at intervals ½ the length of those shown in Table 9-1 of API 570 for piping NOT cathodically protected and at the same intervals as shown in Table 9-1 for cathodically protected piping. a) b) c) d)

5 10 25 50

156)The leak test for a 8" diameter buried piping system is 300 psi. After 7 hours, the pressure reacts 273 psi. What should the inspector do? a) Nothing is required. The loss of pressure is negligible and will not affect the test. The loss can be disregarded. b) The system should be re-pressurised to the original leak test pressure and the test should begin again. c) The test charts and the temperature should be reviewed to determine if any change in temperature caused the pressure drop. d) The piping should be visually inspected externally and / or inspected internally to find the leak and assess the extent of corrosion.

155)The leak test for buried piping should be for a period of __________ hours. a) b) c) d)

4 8 12 24

157) A buried piping system that is not cathodically protected has to have an inspection interval set. The soil resistivity is checked and found to be 3400 ohm/cm. As the inspector, what interval would you set? a) b) c) d)

2.5 years 7.5 years 5 years 10 years

158) Buried piping also may be surveyed for integrity by removing the line from service and performing a leak test. This inspection method typically involves pressurising the line with a __________, allowing time for the __________ to diffuse to the surface and surveying the buried line with a gas-specific detector to detect the __________ a) b) c) d)

Tracer gas (such as helium or sulphur hexafluoride) Light hydrocarbon (such as butane) Smoke type material (such as chemical smoke) Water vapour (such as steam)

159) Repairs to coating on buried piping may be tested using a) b) c) d)

A low-voltage holiday detector Light taps with an inspection hammer A flaw indicator fluid A high-voltage holiday detector

160) If buried piping leaks are clamped and reburied: a) No further action is required unless the piping leaks again b) The date of installation shall be marked on the clamp for future identification c) A record of the location and the date of installation shall be maintained d) The clamped line shall be leak tested.

18)An inspector finds a thin area in the body of a NPS 6, 600 lb. gate valve body. The body is made from ASTM A216 WCB material. The system operates at 900 psi and 750 degrees F. Using a corrosion allowance of 0.125", what minimum required thickness must the valve body have to continue to safely operate? (Round to the nearest 3 decimals) a) b) c) d)

0.492” 0.427” 0.510” 0.345”

t = 1.5x [(900x6.625) / 2(14800)] + 0.125

Important Numbers 重要数据

API 570 规范修改,年限,有效期等

Foreword Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time extension of up to two years may be added to this review cycle. Each edition, revision, or addenda, to this API standard becomes effective six months after the date of issuance for equipment that is rerated, reconstructed, relocated, repaired, modified (altered), inspected, and tested per this standard. During the six-month time between the date of issuance of the edition, revision, or addenda and the effective date, the user shall specify to which edition, revision, or addenda, the equipment is to be, rerated, reconstructed, relocated, repaired, modified (altered), inspected and tested. 每 5年 API 规范修订，重新确认或撤销/一次性延长，最多延长2年, 新版6个月后生效. 发行版,修订至生效期间,用户应指定版，修订或增编受使用

API 570-Important # Fion Zhang/ Charlie Chong

每 5年 API规范修订,重新确认或撤销/一次性延长,最多延长2年 新版6个月后生效. 发行版,修订至生效期间,用户应指定版，修订或增编受使用


CML-测试点面积

3.1.20 examination point 检查点 recording point记录点 measurement point测量点 test point测试点 An area within a CML defined by a circle having a diameter not greater than 2 in. (50 mm) for a pipe diameter not exceeding 10 in. (250 mm), or not greater than 3 in. (75 mm) for larger lines and vessels. CMLs may contain multiple test points. NOTE Test point is a term no longer in use as test refers to mechanical or physical tests (e.g. tensile tests or pressure tests).

直径<10寸管-直径不大于2”圆的 CML or TML 直径>10寸管-直径不大于3”圆的 CML or TML


直径 <10寸管-直径不大于2”圆的 CML or TML 直径 >10寸管-直径不大于3”圆的 CML or TML

CML or TML -是面积(area) 位置, 不是点(point)位置 API 570-Important # Fion Zhang/ Charlie Chong

3.1.72 primary process piping 主要工艺管道 Process piping in normal, active service that cannot be valved off or, if it were valved off, would significantly affect unit operability. Primary process piping normally includes most process piping greater than NPS 2, and typically does not include small bore or auxiliary process piping (see also secondary process piping).

主要工艺管道通常包括

大于NPS 2工艺管道


3.1.87 soil-to-air interface S/A An area in which external corrosion may occur on partially buried pipe. NOTE The zone of the corrosion will vary depending on factors such as moisture, oxygen content of the soil, and operating temperature. The zone generally is considered to be from 12 in. (305 mm) below to 6 in. (150 mm) above the soil surface. Pipe running parallel with the soil surface that contacts the soil is included.

土壤 - 空气界面 12寸潜土 06寸仰望天空 API 570-Important # Fion Zhang/ Charlie Chong

API574 - 7.4.5 Soil-to-air (S/A) Interface If the buried piping has satisfactory cathodic protection as determined by monitoring in accordance with API 570, excavation is required only if there is evidence of coating or wrapping damage. If the buried piping is uncoated at grade, consideration should be given to excavating 6 in. (150 mm) to 12 in. (300 mm) deep to assess the potential for hidden damage. Alternately, specialized UT techniques such as guided wave can be used to screen areas for more detailed evaluation.

如果开挖检验 06寸~12寸潜土


API 574 7.4.5 Soil-to-air (S/A) Interface土壤空气(S / A) 接口。。。。If the buried piping is uncoated at grade, consideration should be given to excavating 6 in. (150 mm) to 12 in. (300 mm) deep to assess the potential for hidden damage. …..

如果埋地管道在土壤/空气接口,涂层脱落,应考虑到挖掘 6” 至 12”以评估潜在隐藏的损伤.


5.1.1 Development of an Inspection Plan 5.1.1.1 --------. A corrosion specialist should be consulted when developing the inspection plan for piping systems that operate at elevated temperatures above 750 °F (400 °C)] ………

400oC

管道系统运行在 o 750 F以上的高温, 制定检查计划时应当咨询腐蚀专家


5.5.9 Injection Point Inspection 注入点检查


5.5.9 Injection Point Inspection 注入点检查

5.5.9 Injection Point Inspection During periodic scheduled inspections, more extensive inspection should be applied to an area beginning 12 in.(300 mm) upstream of the injection nozzle and continuing for at

least (10) ten pipe diameters downstream of the injection point. Additionally, measure and record the thickness at all TMLs within the injection point circuit.


5.7 Condition Monitoring Methods 5.7.1 UT and RT ASME BPVC Section V, Article 23, and Section SE–797 provide guidance for performing ultrasonic thickness measurements. Radiographic profile techniques are preferred for pipe diameters of NPS 1 and smaller. Ultrasonic thickness measurements taken on small bore pipe smaller (NPS 2 and below) may require specialized equipment

NPS 1和更小- RT 射线检测首选 NPS 2 - UT 超声可能需要专门的设备


When ultrasonic measurements are taken above 150 °F (65 °C), instruments, couplants, and procedures should be used that will result in accurate measurements at the higher temperatures. If the procedure does not compensate for higher temperatures, measurements should be adjusted by the appropriate temperature correction factor.

o

当超声波测量用于150 F / o 65 C 检测时, 仪器仪表，耦合剂和程序，应该是能在较高工作温度并能准确的测量结果 API 570-Important # Fion Zhang/ Charlie Chong

Factors that can contribute to reduced accuracy of ultrasonic measurements include the following: f) temperature effects [at temperatures above 150 °F (65 °C)]; h) thicknesses of less than 1/8 in. (3.2 mm) for typical digital thickness gauges;

当典型的超声波数字测厚仪测量厚度小于 1 /8英寸(3.2mm) 可能精度会降低 API 570-Important # Fion Zhang/ Charlie Chong

1/8寸/3.2mm 厚度限制说的是典型的数字测厚仪不是超声横波探测仪啊


ASME BPVC, Section on NDE 没有 3 / 没有 9 RT UT LT/DP MT ET LT AE

ASME BPVC, Section V Article 2 ASME BPVC, Section V, Article 4, Article 5, Article 23 ASME BPVC, Section V, Article 6 ASME BPVC, Section V, Article 7 ASME BPVC, Section V, Article 8. ASME BPVC Section V, Article 10 ASME BPVC, Section V, Article 11


5.8 Pressure Testing of Piping Systems—General NOTE The owner/user is cautioned to avoid exceeding 90 % of the SMYS for the material at test temperature and especially for equipment used in elevated temperature service.

压力试验避免超过90% SMYS


5.8.1 Test Fluid 试验液体。。。。。 another suitable nontoxic liquid may be used. If the liquid is flammable, its flash point shall be at least 120°F (49°C) or greater 。。。。。Piping fabricated of or having components of 300 series stainless steel 。。。 de-ionized/de-mineralized water or steam condensate having a total chloride concentration (not free chlorine concentration) of less than 50 ppm. NOTE Potable water in this context follows U.S. practice, with 250 parts per million maximum chloride, sanitized with chlorine or ozone.

水压试验首选是水, 如用易燃液体, o o 它的闪点至少为120 F/49 C. 奥氏体不锈钢试验用水氯离子浓度含量不能大于 50ppm 饮用水氯离子浓度含量不能大于 250ppm


If potable water is not available or if immediate draining and drying is not possible, water having a very low chloride level, higher pH (>10), and inhibitor addition may be considered to reduce the risk of pitting and microbiologically induced corrosion. 如果缺乏饮用水或者不能立即排水吹干, 考虑非常低的氯化物含量/较高的

pH值> 10

和抑制剂的非标试验水


5.8.3 Test Temperature and Brittle Fracture Considerations .

脆性断裂的注意事项: 一些脆性断裂发生在25% 水压试验压力或8KSI压力(以较低者为准) 金属的温度应保持在至少： >2 in. (5 cm) thick： MDMT + 30oF/17oC <2 in. (5 cm) thick： MDMT + 10oF/ 6oC (不需要大于 120oF/50oC)


5/10/10/~/3 TML 5/5/10/~/Class VI API 570-Important # Fion Zhang/ Charlie Chong

保温层下腐蚀检验间隔 %

损坏保温层-75,50,25 敏感工作温度-50,33,10 API 570-Important # Fion Zhang/ Charlie Chong

API 579-1/ASME FFS-1. Assessment requires the use of a future corrosion allowance • • •

Assessment of General Metal Loss—API 579-1/ASME FFS-1, Section 4. Assessment of Local Metal Loss—API 579-1/ASME FFS-1, Section 5. Assessment of Pitting Corrosion—API 579-1/ASME FFS-1, Section 6.

In some cases will require the use of a future corrosion Allowance •

Assessment of blisters and laminations-API 579-1/ASME FFS-1, Section 7

Assessment not requires the use of a future corrosion allowance • • •

Assessment of weld misalignment and shell distortions- API 579-1/ASME FFS-1, Section 8. Assessment of crack-like flaws- API 579-1/ASME FFS-1, Section 9. Assessment of effects of fire damage-API 579-1/ASME FFS-1, Section 11.


7.1.2 Newly Installed Piping Systems or Changes in Service c) If the probable corrosion rate cannot be determined by either method listed in Item a) or Item b), the initial thickness measurement determinations shall be made after no more than three months of service by using nondestructive thickness measurements of the piping system

腐蚀速率计算: 在缺少用户数据下(a,b 项) 不超过3个月的服务后通过使用无损厚度测量厚度来确定


8.1.4.1 Temporary Repairs When installing a fillet-welded patch adjacent to an existing filletwelded patch, the minimum distance between the toe of the fillet weld shall not be less than:


If the repair area is localized (for example, pitting or pinholes) and the SMYS of the pipe is not more than 40,000 psi (275,800 kPa), and a Fitness-ForService analysis shows it is acceptable, a temporary repair may be made by fillet welding a properly designed split coupling or plate patch over the pitted or locally thinned area (see 8.2.3 for design considerations and Annex C for an example).

如果管材 SMYS 不大于 40,000psi 可通过补丁板角焊临时修复


8.2.3.2 Preheating Preheat temperature used in making welding repairs shall be in accordance with the applicable code and qualified welding procedure. Exceptions for temporary repairs shall be approved by the piping engineer. Preheating to not less than 300 °F (150 °C) may be considered as an alternative to PWHT for alterations or repairs of piping systems initially PWHT as a code requirement

o

o

300 F/150 C 预热温度能有条件代替焊后热处理或作为替代全局环管体热处理, 运用局部焊后热处理的前提条件



9.3.1 Above-grade Visual Surveillance 埋地管道地面监控 The owner/user should, at approximately six month intervals survey the surface conditions on and adjacent to each pipeline path (see 9.2.1).

每6个月地面监控 API 570-Important # Fion Zhang/ Charlie Chong

8.2.7 Pressure Testing 。。。。。The closure weld is a full-penetration butt-weld between any pipe or standard piping component of equal diameter and thickness, axially aligned (not miter cut), and of equivalent materials. Acceptable alternatives are: 1) slip-on flanges for design cases up to Class 150 and 500 °F (260 °C); and2) socket welded flanges or socket welded unions for sizes NPS 2 or less and design cases up to Class 150 and 500 °F (260 °C).

当它是不实际的最终闭合焊缝进行的压力试验最后封焊应当是一种全熔透对焊, 以下除外：计案例 o o 套法兰 Class 150 / 500 F(260 C) 承插焊法兰- Class 150 / 500oF / NPS 2 API 570-Important # Fion Zhang/ Charlie Chong

9.3.4 Soil Corrosivity 土壤腐蚀性 For piping buried in lengths greater than 100 ft (30 m) and not cathodically protected, evaluations of soil corrosivity should be performed at five-year intervals. Soil resistivity measurements may be used for relative classification of the soil corrosivity (see 9.1.4). Additional factors that may warrant consideration are changes in soil chemistry and analyses of the polarization resistance of the soil and piping interface

非阴极保护管道埋在长度大于100英尺/ 30M，每隔五年应进行土壤腐蚀性评价 API 570-Important # Fion Zhang/ Charlie Chong

9.3.5 Cathodic Protection If the piping is cathodically protected, the system should be monitored at intervals in accordance with Section 10 of NACE RP0169 or API 651.

1年- 阴极保护系统维护


9.3.6 External and Internal Inspection Intervals 外部和内部检查间隔 The external condition of buried piping that is not cathodically protected should be determined by either pigging, which can measure wall thickness, or by excavating according to the frequency given in Table 5. Significant external corrosion detected by pigging or by other means may require excavation and evaluation even if the piping is cathodically protected. Piping inspected periodically by excavation shall be inspected in lengths of 6 ft to 8 ft (2.0 m to 2.5 m) at one or more locations judged to be most susceptible to corrosion

非阴极保护管道按照表5 间隔做检验定期“运作智能通管器” 或 “开挖检查” 开挖检验管道长度 6尺~8尺



9.3.7 Leak Testing Intervals 泄漏测试时间间隔

110% MAWP 泄漏实验替代或补充定期检查 • 阴极保护埋地管道: 表5指定时间间隔 • 非阴极保护埋地管道: 表5指定时间间隔减半


1” min Radius

API 570-Important #

插板式修复尺寸要求 Fion Zhang/ Charlie Chong

API 574 7.4.5 Soil-to-air (S/A) Interface土壤空气(S / A) 接口。。。。If the buried piping is uncoated at grade, consideration should be given to excavating 6 in. (150 mm) to 12 in. (300 mm) deep to assess the potential for hidden damage. …..

如果埋地管道在土壤/空气接口,涂层脱落,应考虑到挖掘 6” 至 12”以评估潜在隐藏的损伤.



Understanding Pressure Piping Inspection code API 570-my self study notes

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