scholarly journals Detection and Verification of SCC in a Gas Transmission Pipeline

2000 ◽  
Author(s):  
B. Ashworth ◽  
Neb Uzelac ◽  
H. Willems ◽  
O. A. Barbian
Keyword(s):  
Stress Corrosion ◽  
Wall Thickness ◽  
Stress Corrosion Cracking ◽  
Confidence Level ◽  
Crack Detection ◽  
Corrosion Cracking ◽  
Inspection Method ◽  
Transmission Pipeline ◽  
History Of ◽  
Location Type

Two sections of a 914mm OD (36 in.) TransCanada (TCPL) gas transmission pipeline (predominantly with 9.14 mm wall thickness) were inspected using an ultrasonic liquid coupled crack detection In-Line Inspection (ILI) tool. One of the objectives of the inspection was to establish the condition of the pipeline sections with a known history of stress-corrosion cracking (SCC). Under test was the practicability of inspecting a gas line using a liquid coupled ILI tool, specifically its ability to detect and size defects deeper than 1 mm and distinguish cracks and crack-like defects from other types of anomalies, such as inclusions and laminations. In order to assess the confidence level of the tool, both sections were inspected in two independent runs and the repeatability of inspection was assessed. Cracks and crack-like defects with depths greater than 12.5% of the wall thickness from both runs were compared and correlation was established to assess repeatability. The accuracy of tool predictions was verified in excavations in both sections. 40 reported features, varying in depths up to over 40% were examined with respect to location, type, and size. Examples of defect patterns are shown to demonstrate the accuracy of the inspection method.

Methodology to Develop Fitness-for-Service Assessments for Crack Detection In-Line Inspection Data

2006 ◽  
Author(s):  
David Shanks ◽  
Rob Leeson ◽  
Corina Blaga ◽  
Rafael G. Mora
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Crack Detection ◽  
Corrosion Cracking ◽  
Life Extension ◽  
Remaining Life ◽  
Service Monitoring ◽  
Criticality Assessment ◽  
Inspection Data

Implementation of Integrity Management Programs (IMP) for pipelines has motivated the design of Fitness-For-Service methodologies to assess Stress Corrosion Cracking (SCC) and fatigue-dependent features reported by Ultrasonic Crack Detection (UTCD) In-Line Inspections. The philosophical approach defined by the API 579 [1] “Fitness-For-Service” from the petrochemical industry in conjunction with Risk-based standards and regulations (i.e. CSA-Z662-2003 [2] and US DOT 49 Parts 192 [3] and 195 [4]) and in-line inspection validation (i.e. API 1163 [5]) approaches from the pipeline industry have provided the engineering basis for ensuring the safety, reliability and continued service of the in-line inspected pipelines. This paper provides a methodology to develop short and long-term excavation and re-inspection programs through a four (4) phase-process: Pre-Assessment, Integrity Criticality Assessment, Remediation and Repair, Remaining Life Extension and In-Service Monitoring. In the first phase, Pre-assessment, areas susceptible to Stress Corrosion Cracking (SCC) and fatigue-dependent features are correlated to in-line inspection data, soil modeling, pipeline and operating conditions, and associated consequences in order to provide a risk-based prioritization of pipeline segments and technical understanding for performing the assessment. The second phase, Integrity Criticality Assessment, will develop a short-term maintenance program based on the remaining strength of the in-line inspection reported features previously correlated, overlaid and risk-ranked. In addition, sites may be identified in Phase 1 for further investigation. In the third phase, a Remediation and Repair program will undertake the field investigation in order to repair and mitigate the potential threats as well as validating the in-line inspection results and characterization made during the Pre-assessment and Integrity Criticality Assessment (Phases 1 & 2). With the acquired knowledge from the previous three (3) phases, a Remaining Life Extension and In-Service Monitoring program will be developed to outline the long-term excavation and re-inspection program through the use of SCC and Fatigue crack growth probabilistic modeling and cost benefit analysis. The support of multiple Canadian and US pipeline operating companies in the development, validation and implementation of this methodology made this contribution possible.

The Geometry of Steam Generator Tube and Its Relevance to the Occurrence of Stress Corrosion Cracking in Operating Nuclear Power Plants

2010 ◽  
Author(s):  
Deok Hyun Lee ◽  
Do Haeng Hur ◽  
Myung Sik Choi ◽  
Kyung Mo Kim ◽  
Jung Ho Han ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Steam Generator ◽  
Stress Corrosion Cracking ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Corrosion Cracking ◽  
Location Type ◽  
Steam Generator Tubes ◽  
Non Destructive

Occurrences of a stress corrosion cracking in the steam generator tubes of operating nuclear power plants are closely related to the residual stress existing in the local region of a geometric change, that is, expansion transition, u-bend, ding, dent, bulge, etc. Therefore, information on the location, type and quantitative size of a geometric anomaly existing in a tube is a prerequisite to the activity of a non destructive inspection for an alert detection of an earlier crack and the prediction of a further crack evolution [1].

Use of Alloy Additions to Prevent intergranular Stress Corrosion Cracking In Aluminum Bronze

CORROSION ◽  
1960 ◽  
Vol 16 (10) ◽  
pp. 519t-522t ◽  
Author(s):  
J. F. KLEMENT ◽  
R. E. MAERSCH ◽  
P. A. TULLY
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Boundary Segregation ◽  
Field Testing ◽  
Corrosion Cracking ◽  
Aluminum Bronze ◽  
Intergranular Stress Corrosion ◽  
Actual Application ◽  
History Of ◽  
Intergranular Stress Corrosion Cracking

Abstract The general principles of equilibrium grain boundary segregation are applied to form a theory on the possible elimination of intergranular stress corrosion cracking in alpha aluminum bronze in steam. Various possible alloy additions are discussed in relation to their atom size, solubility, and tendency to react with steam. A theoretical selection of beneficial additions is made. Actual test results on several alloys containing a variety of additions are presented, illustrating good agreement of theory and results. The effects of the additions on transgranular ammonia cracking susceptibility are also discussed. A brief history of the application of laboratory results to field testing and actual application to the product is given. 3.7.2

Ultrasonic Inline Inspection of the Moomba to Sydney Pipeline

2006 ◽  
Author(s):  
Stephen P. Ohl ◽  
Robert E. Allison
Keyword(s):  
Liquid Medium ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Performance Criteria ◽  
Fitness For Purpose ◽  
Efficient Manner ◽  
Transmission Pipeline ◽  
History Of ◽  
The Many ◽  
The One

For the majority of Australian gas pipelines it is not practical to remove them from service for extended periods of time. This rules out hydrostatic testing as a means of confirming the integrity of older pipelines including those that may contain Stress Corrosion Cracking (SCC). The Moomba to Sydney pipeline (MSP) at 864 mm (34 inch) nominal bore and 1299 km (807 miles) in length is the largest diameter onshore gas transmission pipeline in Australia. Commissioned in 1976, it has a history of susceptibility to SCC and, in 1982, six years after commissioning, suffered a SCC initiated rupture. Since this time the pipeline owners have operated and maintained the pipeline to ensure no further SCC initiated failures. Maintenance for SCC has included a targeted excavation program which, between 2000 and 2004, found significant SCC colonies. This created the need to develop a more comprehensive approach to locate and identify every significant SCC colony in the pipeline. Several options were considered but the one that was selected as best meeting the performance criteria was the use of an ultrasonic intelligent pig running in a liquid medium. This pigging operation had to be carried out while the pipeline continued in operation with minimal disruption to gas transmission operation. This had never been done before in Australia. The initial intelligent pigging program of the first 162 km (101 miles) of the pipeline was conducted in early 2005 with an additional 292 km (181 miles) pigged in early 2006. This paper provides information on the approach taken to overcome the many technical, operational and commercial challenges of this operation. Water was chosen as the liquid medium and a major issue was the introduction and removal of water from the pipeline while it remained in operation. This could not have been achieved without the co-operation of producers, shippers, network owners, network operators, technical regulators and contractors. The paper also looks at the how the results obtained from the pigging will be used to enable the SCC to be managed in a safe and efficient manner and confirming the safety and fitness for purpose of the MSP now and into the future.

Development and Experiences of a Circumferential Stress Corrosion Crack Management Program

2018 ◽  
Author(s):  
Neil Bates ◽  
Mark Brimacombe ◽  
Steven Polasik
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Crack Detection ◽  
Circumferential Stress ◽  
Management Program ◽  
Corrosion Cracking ◽  
Pipeline System ◽  
Average Growth ◽  
Proactive Management ◽  
Inspection Data

A pipeline operator set out to assess the risk of circumferential stress corrosion cracking and to develop a proactive management program, which included an in-line inspection and repair program. The first step was to screen the total pipeline inventory based on pipe properties and environmental factors to develop a susceptibility assessment. When a pipeline was found to be susceptible, an inspection plan was developed which often included ultrasonic circumferential crack detection in-line inspection and geotechnical analysis of slopes. Next, a methodology was developed to prioritize the anomalies for investigation based on the likelihood of failure using the provided in-line inspection sizing data, crack severity analysis, and correlation to potential causes of axial or bending stress, combined with a consequence assessment. Excavation programs were then developed to target the anomalies that posed the greatest threat to the pipeline system or environment. This paper summarizes the experiences to date from the operator’s circumferential stress corrosion cracking program and describes how the pipeline properties, geotechnical program, and/or in-line inspection programs were combined to determine the susceptibility of each pipeline and develop excavation programs. In-line inspection reported crack types and sizes compared to field inspection data will be summarized, as well as how the population and severity of circumferential stress corrosion cracking found compares to the susceptible slopes found in the geotechnical program completed. Finally, how the circumferential SCC time-average growth rate distributions were calculated and were used to set future geohazard inspections, in-line inspections, or repair dates will be discussed.

Getting to Know Your Bends to Support SCC Management

2020 ◽  
Author(s):  
Chris Wood ◽  
Fernando Merotto ◽  
Brian Kerrigan ◽  
Ramon Loback ◽  
Pedro Gea
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Crack Detection ◽  
Axial Stress ◽  
Corrosion Cracking ◽  
Inspection System ◽  
Pipe Material ◽  
Baseline Assessment ◽  
Limited Information ◽  
Metallographic Examination

Abstract Nova Transportadora do Sudeste (NTS) own and operate a gas transmission system in Brazil constructed in 1996. One of the confirmed primary integrity threats to this system is axial stress corrosion cracking. The pipelines vary in diameter, weld type, manufacturer and age. One of the pipelines failed in 2015 due to an axial stress corrosion crack. Since the failure, NTS have executed an intense inspection campaign to detect and size axial cracking within their network. The 2015 failure occurred on a field bend. The inspection campaign and following dig campaign has confirmed that cracking (both axial and circumferential) within field bends is the primary integrity threat. Brazil has a challenging terrain and approximately 40% of joints within the network were subject to cold field bending. The influences of the pipeline geometry within these areas have resulted in localised elevated stresses where the axial stress corrosion cracking colonies are initiating and growing. To date, no cracking (axial or circumferential) has been verified within their straight pipe joints. NTS initially took a conservative baseline assessment approach using API 579 Part 9, due to the limited information regarding the pipe material and complex stress state. In addition to the hoop stress from internal pressure, the baseline assessment also considered weld residual stress and bending stress due to ovalization to determine immediate and future integrity. An intensive dig campaign is underway following a crack detection in-line inspection campaign using electromagnetic acoustic transducer technology. A large number of deep cracks were reported by the in-line inspection system, these were verified to be deep and repaired with a type B sleeve. However, at one site an entire joint was removed for further analysis, to investigate the crack morphology, confirm material properties and refine the predictive failure pressure modelling. This paper outlines how NTS have combined a burst test, mechanical testing, FEA modelling, fractography and metallographic examination to further understand the feature morphology and stresses within these areas and how they have been able to reduce conservatism from their baseline assessment with confidence and adopt a plastic collapse approach to accurately predict failure.

scholarly journals Remote detection of stress corrosion cracking: Surface composition and crack detection

2018 ◽  
Author(s):  
Cliff J. Lissenden ◽  
Igor Jovanovic ◽  
Arthur T. Motta ◽  
Xuan Xiao ◽  
Samuel Le Berre ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Crack Detection ◽  
Surface Composition ◽  
Corrosion Cracking ◽  
Remote Detection ◽  
Detection Of Stress
Sign in / Sign up

Export Citation Format

Share Document