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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


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


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


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


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.


http://www.naceinstitute.org/cstm/education/certification/certsearch.aspx


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. M端ller (Nockemann), M. Scharmach Bundesanstalt f端r Materialforschung und Pr端fung (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���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 __________ 째F. 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 __________ 째F 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


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Api570 chapter 5