bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pipeline Diagnostics With Ultrasonic Meters
Authors: Gailey Nicole , Rasool Noman 
Published: November 2016

Canada and the United States have vast energy resources, supported by thousands of kilometers (miles) of pipeline infrastructure built and maintained each year. Whether the pipeline runs through remote territory or passing through local city centers, keeping commodities flowing safely is a critical part of day-to-day operation for any pipeline. Real-time leak detection systems have become a critical system that companies require in order to provide safe operations, protection of the environment and compliance with regulations. The function of a leak detection system is the ability to identify and confirm a leak event in a timely and precise manner. Flow measurement devices are a critical input into many leak detection systems and in order to ensure flow measurement accuracy, custody transfer grade liquid ultrasonic meters (as defined in API MPMS chapter 5.8) can be utilized to provide superior accuracy, performance and diagnostics.
This paper presents a sample of real-time data collected from a field install base of over 245 custody transfer grade liquid ultrasonic meters currently being utilized in pipeline leak detection applications. The data helps to identify upstream instrumentation anomalies and illustrate the abilities of the utilization of diagnostics within the liquid ultrasonic meters to further improve current leak detection real time transient models (RTTM) and pipeline operational procedures. The paper discusses considerations addressed while evaluating data and understanding the importance of accuracy within the metering equipment utilized. It also elaborates on significant benefits associated with the utilization of the ultrasonic meter’s capabilities and the importance of diagnosing other pipeline issues and uncertainties outside of measurement errors.
Past Bank Erosion as a Guide for Bank Erosion Prediction at Pipeline Crossings
Authors: Roberge Laurent , Ferris Gerald , Weatherly Hamish 
Published: November 2016

This paper presents a methodology which uses past bank erosion behaviour as a predictor of future performance. The methodology employed in the bank erosion study consists of the following main steps: identifying a reach to examine, classifying the watercourse, estimating key hydrotechnical properties, obtaining historical air photographs of the reach, georeferencing or orthorectifying the airphotos, mapping the position of the channel edge, obtaining the historical records of nearby gauges to estimate the return period of floods that have occurred between successive pairs of historical air photographs, and finally combining the results to provide correlations between the rates of bank erosion and the rarity of the floods that have occurred.
More than 70 bank erosion studies have been completed in the past two years at a variety of watercourses. This paper provides three case histories that illustrate the methodology and then proceeds to provide some tentative relationships that could be used to focus future bank erosion studies on those sites most active, and used to provide a preliminary estimate of the amount of bank erosion that could be expected in both design settings and existing pipeline integrity evaluations.
In this study wandering rivers are more laterally active than other channel pattern types. Although the smallest floods do not cause large-scale changes to the banks, significant bank erosion can be caused by either moderate (20-year) or extreme (100-year) events with a rough trend to larger bank erosion in larger floods. No significant correlation between the time elapsed between successive air photos and the magnitude of erosion was found, suggesting that bank erosion is an event-driven process rather than time dependent.
Full-Scale Elevated Temperature Testing of Composite Repairs in Bending and Compression
Authors: Sheets Colton , Rettew Robert , Alexander Chris , Axenova Tanya 
Published: November 2016

The increasing use of composite repair systems in critical and complex applications has brought greater scrutiny to their design and performance. This has been especially true in high-temperature, immersed environment applications where ambient temperature test results with industry standard de-rating factors are all that is available for design. Since this approach does not always adequately capture environmental effects or the performance of composite systems at elevated temperatures, it is beneficial to perform full-scale testing which accurately replicates the in-situ application. In order to accomplish this, a full-scale testing program was developed that subjected multiple composite repair systems to internal and external loads at temperatures up to 120 °C with and without water immersion.
This program involved the reinforcement of 12.75-inch × 0.375-inch pipe samples that had simulated corrosion defects. Full-scale load and pressure testing was conducted to simulate the long-term performance of the composite repair systems in the environmental conditions of the application. A strain based performance threshold of 0.4% strain at 120 °C and 100% SMYS was used to develop a competitive program that ranked the participating systems and reduced the number of acceptable repairs from six down to three. This approach increased the efficiency of the full-scale testing and allowed for more in-depth analysis of the top-performing systems.
The results of the full-scale testing of six composite repair systems at elevated temperature allowed for a quantitative measure of their effectiveness under in-situ conditions. Several of the systems were shown to provide inadequate reinforcement under these conditions; however, it was also observed that appropriately designed and installed systems are capable of meeting the intense demands of elevated temperature, harsh-service conditions.
The Development and Use of an Absolute Depth Size Specification in ILI-Based Crack Integrity Management of Pipelines
Authors: Foreman Geoff , Bott Steven , Sutherland Jeffrey , Tappert Stephan 
Published: November 2016

To provide a more insightful and accurate feature description from Crack In-line Inspection (ILI) reporting as per the Fitness For Service analysis in API 1176, individual crack dimensions must be established to a given accuracy. PII Pipeline Solutions established an absolute depth sizing specification conforming to the dig verification processes of API 1163. This change represented a significant shift from a traditional reporting format for depth sizing in “bands” of 1–2 mm, 2–3 mm and > 3 mm depths within crack ILI inspection reporting.
When assessing features with characteristics stated in a sizing band, the pipeline integrity assessment approach required a conservative assumptions that all of the features in that band must be treated as if they are in the deepest band value. The implication then meant that the specification created only 3 sizes of crack depths 1–2 mm, 2–3 mm, > 3 mm (± 0.5mm tolerance at 90% certainty). In practical terms a large quantity of features in the significant band of 2–3 mm must be treated as potential dig candidates with a depth of at least 3 mm, making length characteristics as the only severity ranking basis for any priority dig selection.
Previous attempts at establishing absolute depth sizing for crack inspection required a series of calibration digs. The large sample size over multiple inspection runs and pipeline sections allowed for a statistical specification algorithm is developed as part of the analysis process, therefore no additional reporting time, or excavation cost was involved. The new absolute sizing algorithm has provided operators with a means of prioritizing digs, based upon individual feature length and depths. Replacing the traditional depth bands with individual feature specific peak depths and thereby providing a major step forward in achieving a cost effective process of prioritizing crack mitigation in pipelines.
Following the dig verification process in API 1163, significant populations of infield NDE results were utilized on a variety of pipeline sections of different diameters. Predicted absolute depth estimation accuracy was determined for specific feature types and thereby created a depth tolerance, with statistical certainty levels established that match those available and recognized with metal loss ILI. This paper describes the process and the means by which an absolute depth crack ILI specification was established using characteristics from a significant set of real features. It also describes benefits realized within pipeline integrity engineering of moving to such a new reporting protocol.
Experimental Study on Inverse Fracture in Drop-Weight Tear Test and Other Laboratory Test: Current Activities in HLP Committee, Japan, Report 2
Authors: Tagawa Tetsuya , Fujishiro Taishi , Amano Toshihiko , Aihara Shuji , Igi Satoshi 
Published: November 2016

The drop-weight tear test (DWTT) has been widely used to evaluate the resistance of linepipe steels against long brittle fracture propagation. However, there is an ambiguity in its evaluation if the inverse fracture appears (100% shear area prior to cleavage fracture from the notch) on the DWTT fracture surfaces. Although cause of the inverse fracture is not fully understood, compressive pre-straining near the impact hammer has been discussed as a possible cause.
In the present work, DWTTs for X65, X70 and X80 were performed. In addition to conventional DWTT specimen with a pressed notch (PN), PN specimen with a back slot and specimens with a chevron notch (CN) or a static pre-cracked (SPC) were examined. The fracture appearances were compared in the different strength and in the different initial notch type. The frequency of the inverse fracture appeared in these DWTTs were different in each material and each specimen type, but there were no cases free from the inverse fracture.
The inverse fracture was investigated by fractography and the hardness profiles along the under layer of the fracture surfaces. Also, the strain histories during impact in DWTTs were measured by the digital image correlation technique based on the high-speed camera images.
The DWTT specimen purpose is to evaluate the brittle crack arrestability of the material in a pressurized linepipe. The DWTT results should be examined with a manner of a running brittle crack in a pressurized linepipe. A large scale brittle crack arrest test, so called temperature gradient ESSO test was also performed for X65 mother plate. The shear area fraction measured in DWTT fracture appearance was compared with the local shear lip thickness fraction in ESSO test. The count of the inverse fracture was discussed in comparison with the long brittle crack arrest behavior in ESSO test.
Fracture Behavior in West Jefferson Test Under Low-Temperature Condition for X65 Steel Pipe With High Charpy Energy: Current Activities in HLP Committee, Japan, Report 1
Authors: Amano Toshihiko , Igi Satoshi , Sakimoto Takahiro , Inoue Takehiro , Aihara Shuji 
Published: November 2016

This paper describes the results of pressure vessel fracture test which called West Jefferson and/or partial gas burst testing using Grade API X65 linepipe steel with high Charpy energy that exhibits inverse facture in the Drop Weight Tear Test (DWTT).
A series of pressure vessel fracture tests which is as part of an ongoing effort by the High-strength Line Pipe committee (HLP) of the Iron and Steel Institute of Japan (ISIJ) was carried out at low temperature in order to investigate brittle-to-ductile transition behavior and to compare to DWTT fracture behavior. Two different materials on Fracture Appearance Transition Temperature (FATT) property were used in these tests. One is −60 degree C and the other is −25 to −30 degree C which is defined as 85 % shear area fraction (SA) in the standard pressed notch DWTT (PN-DWTT). The dimensions of the test pipes were 24inches (609.6 mm) in outside diameter (OD), 19.1 mm in wall thickness (WT). In each test, the test pipe is cooled by using liquid nitrogen in the cooling baths. Two cooling baths are set up separately on the two sides of the test vessel, making it possible to obtain fracture behaviors under two different test temperatures in one burst test. The test vessel was also instrumented with pressure transducers, thermocouples and timing wires to obtain the pressure at the fracture onset, temperature and crack propagation velocity, respectively.
Some informative observations to discuss appropriate evaluation method for material resistance to brittle facture propagation for high toughness linepipe materials are obtained in the test. When the pipe burst test temperatures are higher than the PN-DWTT transition temperature, ductile cracks were initiated from the initial notch and propagated with short distance in ductile manner. When the pipe burst test temperatures were lower than the PN-DWTT transition temperature, brittle cracks were initiated from the initial notch and propagated through cooling bath. However, the initiated ductile crack at lower than the transition temperature was not changed to brittle manner. This means inverse facture occurred in the PN-DWTT is a particular problem caused by the API DWTT testing method. Furthermore, results for the pipes tested indicated that inverse facture occurred in PN-DWTT at the temperature above the 85 % FATT may not affect the arrestability against the brittle fracture propagation and it is closely related with the location of brittle fracture initiation origin in the fracture appearance of PN-DWTT.
Development Towards a Novel Approach for Assessment of Corroded Pipe
Authors: Wilkowski Gery M. , Krishnaswamy Prabhat , Uddin Mohammed , Punch Ed , Hioe Yunior 
Published: November 2016

This paper describes an initial feasibility effort completed in a Small Business Innovative Research (SBIR) Phase I project for DOT-PHMSA to develop a novel approach for the assessment of the remaining strength of corroded pipe. The goal was to assess what failure criterion might be for modern line-pipe steels (e.g., X80) compared to pre-1970 pipes that were used to validate the B31G and RSTRENG methodologies[1]. In the process, the methodology will be able to handle many situations that B31G cannot handle, i.e., high longitudinal stress, corrosion that is more circumferentially oriented than axially oriented, interactions of longitudinal and hoop stresses, and multiple adjacent corrosion patches without empirical criteria.
For the assessment of improved failure criteria, two series of SENT specimens were tested with a systematic variation in the bluntness of the notch from sharp crack to large radii. This was done for a 1960 vintage X52 steel, and a modern X80 steel. The sensitivity to notch acuity was much lower in the modern X80 steel, but both steels had ductile fracture start before maximum load even with the bluntest flaw.
To better assess the driving force, an automated meshing system was pursued, where field laser scans of corroded pipe surfaces were used to created detailed 3D FE meshes of the corrosion profile. One example case was used to assess all the nuances of creating the FE mesh in an automated system, which is quite complicated. The results were used to compare predictions for this case to B31G, Modified B31G, and RSTRENG predictions using the X80 steel pipe properties. In the process of these initial FE analyses, it was found that the assumption used in the B31G type analyses (including RSTRENG) used an equivalent flaw depth with the flaw actual length, whereas the more accurate procedure would be to use the maximum flaw depth with an equivalent length.
The system if developed is intended to be Cloud-based on the Ohio State Supercomputer Center, so that anyone world-wide could conduct such FE analyses without having to have a license for the FE solver software or a supercomputer. Such a validated FE analysis would also a B31G Level 3 analysis.
Basic Performance of Normal Incidence Method for Inspection of Middle Zone of Wall Thickness of LSAW Steel Pipes
Authors: Matsui Yutaka , Iizuka Yukinori 
Published: November 2016

This paper describes the performance of the ultrasonic normal incidence method as a technique for inspection of the middle zone of wall thickness of LSAW (Longitude Submerged Arc Welding) steel pipes. Generally, the tandem method is applied to LSAW seam inspection of the middle zone of wall thickness. However, it is difficult to adjust the locations and angles of each probe.
Therefore, the normal incidence method using one probe for inspection of the middle zone of wall thickness was studied. Because the probe arrangement is simple, it is possible to reduce the time and effort required to adjust the probe location and angle. In the normal incidence method, it is possible to transmit and receive a mirror reflection because the ultrasonic wave is transmitted perpendicularly to a planar flaw under a high refraction angle. As a result of comparison experiments of the normal incidence method and tandem method, the amplitude of the echo from flat bottom drilled hole (F.B.H.) is 12dB higher in the normal incidence method than in the tandem method. The normal incidence method also has wide area sensitivity in the circumferential direction, however, the amplitude of the reflection echo changes ±25% when the incidence angle of the pipe changes ±0.3°. Thus, in practical applications, strict control of the deviation of the pipe incidence angle is necessary. This suggests that the reliability of this technique can be improved by compensating for sensitivity variations, for example, fluctuations associated with tracking backlash.
Thermal Response of Gas Pipeline Metal to Gas Decompression
Authors: Godbole Ajit , Michal Guillaume , Lu Cheng , Venton Philip , Colvin Philip 
Published: November 2016

During natural gas pipeline processes that involve severe depressurization (e.g. blowdown), the gas experiences very significant cooling. The general impression in the industry has been that the adjacent pipeline metal also experiences cooling to a comparable extent. Should this actually be the case, the metal would be rendered susceptible to embrittlement. This would increase the possibility of fracture, thus compromising the integrity of the pipeline. To avoid the perceived possibility of fracture, pipeline design specifications tend to recommend special materials that can withstand low temperature. Such materials are often very expensive.
However, recent experimental and analytical investigations into the heat transfer effects during pipeline decompression have shown that although the gas does undergo considerable cooling during events such as blowdowns, the metal is not cooled to nearly the same extent. These investigations resulted in a model of the blowdown. The model was based on the finding that the thermal response of the pipeline metal at a particular location is largely determined by the formation of a sharp negative spike in the gas temperature as the decompression wave passes that location.
The present paper offers a more detailed version of the blowdown model, taking into account the transient temperature variations through the thickness of the pipe wall. The additional investigations offer insight into the phenomenon of ‘thermal shock’ in the pipeline metal. It is found that the metal response to a thermal ‘spike’ differs markedly from that to a thermal ‘shock’ imposed on the surface of the metal. It is shown that the possibility of damage due to unequal expansion/contraction in the material across the pipe wall thickness is minimal during a blowdown.
Probabilistic Assessment of Crack Detection ILI Effectiveness for Managing Stress Corrosion Cracking on Buried Pipelines
Authors: Tehsin Nauman , Al-Saif Abdulaziz , Qurashi Mosa M. , Polasik Steven J. , Bubenik Thomas A. 
Published: November 2016

Continuous management of Stress Corrosion Cracking (SCC) on buried pipelines is an important element of an Integrity Management Program. Crack detection inspection tools have been widely used in the pipeline industry for locating SCC. There are some potential limitations with these tools; therefore estimating the probability of detection (POD), probability of identification (POI) and sizing accuracy is essential to validate the inspection results. The relationship between field-identified and ILI-reported features is a key component.
This paper probabilistically assesses detection, identification, and sizing accuracy of a crack detection ILI tool. The paper also describes a procedure for estimating the true defect population from the number and severity of SCC features reported by an ILI using statistical analyses. As part of the analyses, transition matrices were developed.
The ILI data set was generated from 26 pipelines with a known history of SCC defects. Excavation data was collected from field reports where over 300 crack-like features were identified by Nondestructive Examination (NDE). The results obtained from the field were compared against the ILI reported features and ILI detection limits.
Statistical models using three-parameter (shape, scale, and threshold) Weibull distributions were found to best model the depth and length distributions. The statistical analyses were based on results from True Positive features (i.e., reported by ILI tool and found in the field), False Negative features (i.e. not reported by the ILI tool and found in the field to be above the detection threshold of the ILI tool), and Unreported features (not reported by the ILI tool and found in the field to be below the detection threshold of ILI tool).
To determine the impact of an excavation program after an ILI run, an approach was developed to analytically grow the defects over time. Probabilistic models were then used to predict ILI feature lists and simulate prior and future ILI results from the defect population. This task was performed by creating an inverse transition probability matrix. The methodology is the basis for the development of line-specific SCC Management Programs.
De Facto Hydrostatic Test Pressures: A Study in Double Stroking
Authors: Warman David J. , Gruzdowich Nicholas J. , Kleeman Harold E. , Boardman Sean C. , Duruike Ugochukwu N. 
Published: November 2016

The pipeline industry has traditionally utilized the double stroke method to limit pipe yielding during pressure testing. Yet few case studies are available which indicate the actual state of stress in a pipeline segment where the pressure — volume plot indicates that the double stroke point has been reached. Examination of a typical stress-strain curve of pipeline steel indicates that the double stroke point typically occurs midway between the elastic limit and the defined yield strength and that the elastic limit can occur at 80% of the defined yield stress.
The purpose of this paper is to develop a model to better understand the actual stresses a pipeline experiences during a hydrostatic test. For analysis, the double stroke point is used as the test case, which results in insights about the actual stresses seen on the pipeline and an understanding about what double stroking actually means. The double stroke point was chosen for analysis since it is commonly used as a ceiling on hydrostatic test pressure and, although literature provides clarity on its definition, few experiments and tests have been performed to gain a practical understanding of its affect on a pipeline.
Analysis was done on a real world example and the results were compared to a Monte Carlo simulation to model the sensitivity of the various parameters. The results of the real world test case of known pipe attributes indicated that the strains in all pipe joints would stay below 0.5% at the double stroke point. When a Monte Carlo simulation was applied to the pipe variables of the same test section, 0.5% strain was exceeded on several outlying joints, but in those cases the hoop stress utilizing Barlow’s equation was in-excess of 125% SMYS. The analysis in this paper provides a tool for predicting the range of actual stresses the pipeline is experiencing when hydrostatically tested, and in doing so, also provides a firmer grasp on what double stroking actually means for a pipeline.