Api570 b my self study notes by charlie Chong

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

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

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 â&#x20AC;&#x201C; 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

Charlie Chong/ Fion Zhang/ He Jungang / Li Xueliang

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.

Charlie Chong/ Fion Zhang/ He Jungang / Li Xueliang

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

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 ă&#x20AC;&#x20AC; 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 15.75â&#x20AC;?, 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-Â˝ 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 .7385â&#x20AC;?. The system had no thickness measurements taken until 1995, at which time the measured thickness was .603â&#x20AC;?. 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 .844â&#x20AC;?. 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 10.75â&#x20AC;?. 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)

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

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 500째F) 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)

0.01996”/year 0.02567”/year 0.02114”/year 0.03546”/year

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 4â&#x20AC;&#x201D;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 = 0.0555â&#x20AC;?/yr Cr Short= (0.54-0.40)/2 = 0.07â&#x20AC;?/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. â&#x20AC;ŚIn 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. â&#x20AC;&#x153; 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 treatmentâ&#x20AC;? 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:

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 = 0.0065â&#x20AC;?/yr Cr short = (0.31-0.3)/2 = 0.005â&#x20AC;?/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 = 0.0065â&#x20AC;?/yr CR short = (0.31-0.3)/2 = 0.005â&#x20AC;?/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?â&#x20AC;&#x153; 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

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.

Charlie Chong/ Fion Zhang/ He Jungang / Li Xueliang

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

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)

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?â&#x20AC;&#x153; 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)

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 â&#x20AC;&#x201C; 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 __________ 째F 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 째F (10 째C), 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 째F (0 째C). 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 30â&#x20AC;&#x201D;Wenner Four-pin Soil Resistivity Test

API574: Figure 31â&#x20AC;&#x201D;Soil Bar Used for Soil Resistivity Measurements

API574: Figure 32â&#x20AC;&#x201D;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.

Charlie Chong/ Fion Zhang/ He Jungang / Li Xueliang

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 Â˝ 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

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

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 570-Important # 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.

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

5.5.9 Injection Point Inspection 注入点检查

API 570-Important # Fion Zhang/ Charlie Chong

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.

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

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.

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

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

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)

API 570-Important # Fion Zhang/ Charlie Chong

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.

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

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:

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

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

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

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

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

API 570-Important # Fion Zhang/ Charlie Chong

1” min Radius

API 570-Important #

插板式修复尺寸要求 Fion Zhang/ Charlie Chong

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.

API 570-Important # Fion Zhang/ Charlie Chong