bluuebunny/crossref_metadata_2025 huggingface dataset:
PR-015-13606-R01 Ultrasonic Meter Performance in Liquid Transients
Authors: Hawley  , Thorson
Published: August 2023

This research evaluated the performance of select ultrasonic meters in natural gas flows before, during, and after transient liquid contamination from compressor oil and glycol. The research program evaluated the performance recovery characteristics of each ultrasonic meter after an extended period of dry gas flow and after meter cleaning. The diagnostics of the meters were also monitored to determine if they could be used to determine the presence of liquid contamination.
PR-317-10701-R01 Temperature Logging as a Mechanical Integrity Test (MIT) for Gas-Filled Caverns
Authors: Voegeli Sam
Published: August 2023

This report documents the work performed to evaluate the possibility that temperature log anomalies (�cold spots� or departures from temperature linearity with depth) can be indicators of well leaks. The natural gas cavern storage industry does not have a methodology for accurate gas-filled cavern well Mechanical Integrity Tests (MITs). Analyses of some temperature log anomalies in North American gas cavern well completions revealed that temperature log anomalies can be indicators of well leaks. The challenges in applying this technology to quantify gas-filled cavern MITs are threefold: (1) Does a temperature anomaly (�cold spot�) always indicate a leak? (2) Can a leak magnitude be correlated to a temperature log anomaly magnitude? and (3) What protocol should be used for executing such an MIT?

This report is not intended to completely address all three issues noted above. However, the research presented here is one of many steps needed to evaluate the possibility of temperature logging as an MIT. Research activities discussed in this report involve computational fluid dynamics (CFD) modeling of both a well and cavern. Specifically, the response from a representative cold spot introduced in the cement sheath of a well and the response from an actual leak are addressed.
PR-015-143601-Z01 Drying Time of Residual Hydrotest Water in Crevices and Dead Legs
Authors: Das  , He
Published: August 2023

The objective of this project was to evaluate the effectiveness of the dewatering process after hydrotesting and to examine the internal corrosion threat posed by residual water trapped in crevices and water pushed into a dead leg. A "time to dry" calculation for both cases was conducted based on pipeline operating conditions. Analysis of the evaporation of water trapped in crevices indicated that maintaining low pressures and high temperatures are the most effective measures for drying the trapped water. At the lowest pressure of 14.7 psi and at 100 �F, trapped water can be dried in days. At increased pressure or decreased temperature, a pipeline may become saturated with water vapor, completely stopping evaporation. Other factors such as crevice geometry, water content, and water type had insignificant effects on water drying from a crevice. The geometry considered for water drying in a dead leg included the entire dead leg, a section of the main line, and a section of the lateral line in a horizontal orientation. Analysis indicated that gas flow in the main pipe forced the accumulated liquid water from the dead leg to move upstream in the main and subsequently evacuate through the lateral and pipe exit. The process of purging 99% of the liquid water from the dead leg was rapid, usually within minutes into operation of the pipeline. However, the small droplets, streaks and globules of water that are left behind may take a longer time to evaporate or be purged. A sloped dead leg configuration may enable a standing pool of water to accumulate in the dead leg, which would take substantially longer to evaporate than small water droplets. Further study that ac-counts for different dead leg orientations is recommended to provide a more complete understanding of the internal corrosion risk in dead legs.
PR-179-13207-R01 Variable Fuel Composition Air Fuel Ratio Control of Lean Burn Engines
Authors: Ladd  , Neuner  , Olsen
Published: August 2023

This research evaluates the effects of variable fuel quality on a large bore 2 stroke natural gas engine by varying ethane in the fuel gas from 5 to 25%. Four control strategies were evaluated at ~2 g/bhp-hr NOx, constant boost control, trapped gas ratio (TGR) control, trapped equivalence ratio (TER) control and a novel NOx sensor feedback control methodology. These control approaches were evaluated during variations in intake manifold temperature, relative humidity, ethane volume percentage, and engine speed. Emissions, combustion parameters, controller performance, and engine performance were measured and compared. During a second phase of testing the impact of fuel quality and other parameters (ignition timing, air manifold temperature, and TER) on detonation was explored at ?15 g/bhp-hr NOx. Techniques to quantify detonation were also evaluated, including a commercial accelerometer based system by Altronic. It was determined that ignition timing was the most effective method to control engine detonation. Fuel composition and TER were shown to have a significant effect on the severity of detonation. It was noted that persistent detonation lead to a steady increase in NOx production, but NOx values alone were inadequate to quantify detonation. At completion of engine testing the operational parameters were analyzed to create predictive models to determine if the engine would begin to detonate based on fuel composition, ignition timing and TER. The generated models accurately predicted the detonation level of the engine.

This report has a related webinar.
PR-453-134504-R02 Pipeline On-Bottom Stability Software Upgrade Milestone II
Authors: Abdolmaleki Kourosh , Rawlinson Andrew
Published: August 2023

The scope of work for phase I of PR-453-134504 included implementation of the Verley and Lund [1] clay soil model in Level 2 of the PRCI on-bottom stability (OBS) software. Throughout the implementation process, a number of apparent discrepancies between the code and the documentation in relation to the pipe-soil interaction (PSI) model were identified and raised with PRCI.

In Phase 2 INTECSEA was tasked to formalize these observations and provide more background information to PRCI for further clarification.

The execution strategy was to host a series of meetings with a focused group of PRCI team members to review various topics of soil model in Level 2 and prepare a technical note that captures the issues discussed.

This document presents the technical note on the PSI topics and clarifies INTECSEA's suggestions for further work on this matter. A summary of the technical queries along with ITS recommendation is presented in Table 1-1. Further detail on each topic is available within the report.
PR-015-15610-R01 Effect of Upstream Piping Configurations on Ultrasonic Meter Bias
Authors: Hawley  , Grant
Published: August 2023

This project investigated the performance of four different brands of commercially available ultrasonic meters installed in an AGA-9 default configuration in two different header designs. The diagnostics from the flow meters were analyzed to determine if they could be used as an indication of bias in the flow measurement. The results from this project were also compared to previous PRCI projects where similar headers were experimentally tested and modeled using CFD. The results of this report are blinded as to meter make/model.
L30570 Earth Current Effects on Buried Pipelines - Telluric Gradients and Their Effects
Authors: Gideon  , Hopper  , Thompson
Published: August 2023

This report is the third phase of a research program to determine the effects of earth currents on buried metallic structures such as pipelines. In the past, stray currents from direct current sources have been observed to cause severe corrosion problems. For this reason, the research program was initiated. The first phase of the program (detailed in Catalog #L30500) consisted of the develoopment of a mathematical model which simulates the conditions and the effects upon a pipeline system located in a soil environment transmitting earth current caused by a direct current system. The second phase consisted of field tests on pipelines in Ohio and Vancouver, B.C. This phase of the research program has been an effort to obtain data on the effects of natural earth currents on buried structures and to assess their possible significance.Four pipelline companies contributed data to this project. This report describes the equipment, sites, pipelines, procedures, and results. This work has shown that effects caused by telluric gradients can be observed on pipelines. However, it is concluded that these effects do not contribute significantly to corrosion.
L51885 Analysis of DOT Reportable Incidents for Gas Pipelines 1985 Through 2000
Authors: Zelenak  , Haines  , Kiefner
Published: August 2023

This document presents an analysis of "Reportable Incidents" on gas transmission and gathering pipelines in the U.S. during the 16-year period from 1985 through 2000.
BTOOJ1O External Corrosion Probability Assessment for Carrier Pipes Inside Casings
Authors: Rankin  , Mahrous
Published: August 2023

This report contains the results of review of literature related to external corrosion of carrier pipes inside casing, descriptions of related corrosion mechanisms, descriptions of related corrosion detection techniques and methodologies, and the results of cathodic protection shielding and related testing using realistic pipe-casing models. The report additionally contains methodologies for Casing Corrosion Direct Assessment (CCDA) and risk assessment, descriptions of corrosion prevention and remediation methods, descriptions of monitoring techniques, and recommendations for future research. The primary intent of this report is to provide pipeline operators with a consolidated body of work that will assist the pipeline operators with development and implementation of procedures for dealing with external corrosion and cathodic protection issues related to carrier pipes inside casings, or that will assist with improvement of existing pipeline operator procedures.
PR-015-15601-R01 Pulsation Effects on Ultrasonic Meters Phase II
Authors: George Darin , Grant Christopher
Published: August 2023

Transmission and storage operations frequently move natural gas using reciprocating compressors that may generate flow pulsations. Most measurement systems cannot accurately measure the flow rate of a pulsating gas stream, and the resulting errors can cause inaccurate gas volumes and accounting imbalances. A previous PRCI research project tested whether recent advances in ultrasonic meters may allow them to function without measurement error in pulsating flows. This project expanded on the previous work and tested similar ultrasonic meters to look for relationships between ultrasonic meter transducer sampling rates, the frequency and amplitudes of pulsations from reciprocating compressors, and meter accuracy. Diagnostics and flow data were collected from the meters and analyzed, and a useful relationship was found between the pulsation conditions and the meter measurement error. The findings were used to recommend a basis for installing ultrasonic meters in gas pipelines with varying pulsations. Additional testing evaluated a fast-response differential pressure transducer connected across a plate flow conditioner as a potential pulsation diagnostic tool.
PR-214-144500-R01 Weld Hydrogen Cracking Susceptibility Characterization
Authors: Dinovitzer Aaron
Published: August 2023

Hydrogen cracking has been and continues to be observed in both heat-affected zones and weld metals. High carbon equivalent weldment heat-affected zones (HAZ) combined with rapid cooling have been related to the development of hydrogen cracking susceptible microstructures. Weld metal cracking is observed in both high and low strength weldments and is a particular concern for root passes due to the use of cellulosic electrodes, parent metal dilution, applied load, and weld fault stress riser effects promoting cracking. The risk of HAZ and weld cracking are increased for repair and in-service welds and/or welds deposited on older generation materials (e.g., pipe or fittings) and this can pose a significant risk to the integrity of welded connections. This report presents the result of the first year of research toward the application and extension of the �Slow Bend� testing technique used to quantify the hydrogen cracking susceptibility of a weldment. This testing is being used to quantify the susceptibility of a microstructure to hydro-gen cracking by defining the critical combinations of strain and hydrogen concentration that result in cracking in a given material. The testing and modelling results complete in this first year of work are planned to support the definition of a Hydrogen Embrittlement characterization technique considering the effects of strain and hydrogen concentration for a material.
PR-343-06605-R01 Analysis of Recalibration Data in the Public Domain
Authors: Group Letton-Hall
Published: August 2023

Public domain information on USM recalibration was reviewed. Additional publications have addressed the stability of USM�s that are permanently installed in the flow calibration loops at Certified Flow Calibration facilities.
QI1L4BF Comparison of Direct Assessment to Other Pipeline Integrity Assessment Methods
Authors: Kiefner  , Haines
Published: August 2023

The purpose of this project is to compare the attributes of three pipeline integrity assessment methods: direct assessment, hydrostatic testing, and in-line inspection.

Technical Perspective:
In conjunction with on-going work by others to establish methods for conducting direct assessments and to establish the reliability of those assessments, this report shows how the evolution of direct assessment has brought it to a level that makes it comparable to other pipeline integrity assessment methods.

Technical Approach: The benefits and limitations of hydrostatic testing, in-line inspection, and external corrosion direct assessment are discussed. The report points out how the work by others on external corrosion direct assessment leads to a calculable level of the probability of a failure after such an assessment. The other methods of pipeline integrity assessment, hydrostatic testing, and in-line inspection also assure a maximum probability of failure. The probability of failure becomes the basis for comparisons between any two or all three methods.
L51564 Emissions Data for Engines Used by the Gas Pipeline Transmission Industry
Authors: Fanick  , Dietzmann  , Urban
Published: August 2023

Final Report; covers the annual phases of a two-phase effort to expand the data collected in the companion document (Compilation, L51565). Each annual section is approximately 100 pages and describes the test procedure and selection criteria for the 22 engines and 6 turbines added by the project.
L52361 Smart USM Diagnostics - Phase I
Authors: Zanker
Published: August 2023

It has long been known that all ultrasonic flow meters, especially those that exploit multiple paths to achieve higher accuracies are capable of extensive self-diagnosis. However, each manufacturer of the technology has tended to develop diagnostic tools specific to each particular device. This has led to a confusing mix of offerings that are not transportable between meters, and whose interpretations are not always consistent.
L52052 Control of Horizontal Beam Width with Phased Array Transducers
Authors: Zhang
Published: August 2023

Accurate defect sizing is becoming more and more critical in pipeline welds due to the application of Engineering Critical Assessment, demanding deep sea applications, the arrival of high performance piping, and increased public safety demands. This project improved horizontal beam focusing for automated ultrasonic testing; curved arrays, focused lenses and electronic focusing using phased arrays were investigated. Two target applications were selected: thickwalled risers and tendons, and thinner walled high performance pipes for onshore.

Extensive computer modeling was performed to optimize the focusing. The recommended array for thick-walled pipes has 360 elements in three rows, and is mechanically curved. The results from this 1.5D and a standard 1D array on a thick-wall calibration block showed that the 1.5D array had significantly better sizing. Also important, side lobes were significantly reduced.

Computer modeling showed that a 60 element, 1 mm pitch array with a 100 mm curvature gave significant improvements over the standard unfocused array. The experimental results showed a significant improvement; the curved array oversized FBH reflectors by only ~1 mm, instead of the 4�6 mm from the unfocused array. These curved arrays can be used on PipeWIZARD with no modifications to the general mechanics or software.
L52103 Differentiation of Corrosion Mechanism by Morphological Feature Characterization - Experimental
Authors: Brossia  , Sridhar
Published: August 2023

Natural gas pipeline systems often contain liquid water and other corrosive agents such as salts, CO2, H2S, O2, and bacteria. The ability to differentiate between corrosion mechanisms is crucial, if corrosion control and mitigation schemes are to be effective. The present project was undertaken to determine whether pipeline steels develop characteristic morphological features that are diagnostic to distinguish between abiotic and biotic pitting corrosion. The present report describes the experimental approach taken to conduct the tests. A separate report (by Exponent Failure Analysis Associates, Menlo Park, CA) will describe the findings and implications of the research.

The work conducted has led to the development of a unique test system that enables introduction of bacterial consortia under conditions simulating operational pipelines. The test system also promotes the growth of sessile over planktonic bacteria. A significant difficulty encountered in conducting the tests is ensuring truly abiotic conditions. Several different steps and procedures were attempted to sterilze the testing system, however, due to its complexity this still proved highly difficult. It is suggested that future abiotic tests either be conducted in a completely separate system or biocides introduced to kill any opportunistic bacteria that may be present or introduced into the system.
PR-218-074503-R01 Effectiveness of Current ROW Monitoring Processes
Authors: Kiefner John
Published: August 2023

The objective of this project was to assess the effectiveness of oil and gas operators transmission operators to prevent unauthorized excavations and encroachments on their rights of way in order to protect their buried pipelines from being damaged.
PR-015-08606-R01 Assessment of Dirty Meter Performance
Authors: Grimley
Published: August 2023

Like most metering technologies, ultrasonic meters are known to be affected by the buildup of material inside the meter and surrounding pipe due to common pipeline contaminants. The buildup affects the metering accuracy by reducing the flow area sampled by the ultrasonic transducers and by changing the shape of the velocity profile through the creation of additional roughness elements on the pipe wall. The goal of this project was to relate the contamination level to the measurement error. The approach was to evaluate the flow measurement performance of two commercially-available ultrasonic flow meters under conditions in which there were various levels of coating on the pipe upstream of the test meter. The tests were performed under controlled conditions in the SwRI Metering Research Facility (MRF) High Pressure Loop and were designed to compare the baseline (clean pipe) flow measurement performance of each meter to the performance attained with various levels of coating on the upstream pipe.
PR-362-06208-R01 Evaluation of Byproduct Emissions from Gas Turbine SCR Catalyst
Authors: Swanson Dr. Larry , Samuelson Christopher
Published: August 2023

The primary objective of the test program was to evaluate byproduct emissions at steady state and transient operating conditions for two commercially available SCR catalysts used in gas turbine applications. Both NOX removal efficiency and ammonia slip behavior were also examined to validate expected catalyst trends and activity. Even though the study replicated expected field catalyst process conditions as well as possible (e.g., flue gas temperatures, space velocities, and inlet species concentrations), the data and results are from pilot-scale testing only, and consequently may differ from actual gas turbine field tests.
PR-418-123710-R01 Mitigating the Hazards Produced by Ruptured Pipelines
Authors: Merilo  , Shockey  , Simons
Published: August 2023

Identifies concepts for mitigating the hazards that can result from a ruptured pipeline. SRI was asked specifically to evaluate blast hazards and identify ideas, materials, methods, and technologies that show promise for mitigating blast effects in high-consequence areas. This report presents indings, recommends concepts for hazard mitigation, and lays the groundwork for evaluating and further developing the envisioned concepts through computational modeling and small-scale testing.
PR-201-124503-R01 Composite Material Reinforcement as an Alternative Method for Determination of MAOP
Authors: Alexander
Published: August 2023

The objective of this project is to evaluate reinforcing technologies, specifically, the use of composite materials for the MAOP determination of high-pressure gas or liquid transmission pipeline systems. Reinforcing a pipeline using composite materials is not for the purpose of providing strength to a damaged section. Rather, the intent is to use composite materials to establish a Maximum Allowable Operating Pressure (MAOP) with an improved safety factor as required by DOT 192 for pipelines that have been subjected to encroachment involving the construction of facilities on or near the pipelines. Emphasis in this discussion is placed on the increased safety factor that is most often accomplished with line replacement using thicker-wall pipes or higher grade steel. The objective of the MATR-3-9 project is to evaluate reinforcing technologies, specifically, the use of composite materials for the MAOP determination of high-pressure gas or liquid transmission pipeline systems. This report provides a state-of-the-art assessment of composite materials in their current usage in reinforcing and repairing damaged pipelines. A discussion is also included regarding the technical aspects for properly designing a composite system for reinforcing non-damaged pipelines, as well as limits that should be imposed on the proposed methods.
L52113 Circumferential MFL In-Line Inspection for Cracks in Pipelines
Authors: Nestleroth
Published: August 2023

Circumferential MFL is a new implementation of a widely used technology that has potential to provide improved detection and quantification of axially oriented defects such as cracks, seam weld defects, mechanical damage, and groove corrosion.

The objective of this project was to improve detection of cracks by changing the implementation along with using data from overlapping and complementary inspection techniques. Two technology advancements were investigated: combining high- and low-magnetization technology for stress detection and combining axial and circumferential MFL methods.

While circumferential MFL and the performance enhancements developed on this project may have limitations, this technology is reasonably well suited for assessing long axially oriented corrosion, which is a challenging anomaly for traditional axial MFL.
PR-273-07202-R01 Gas Turbine Driven Compressor Station Efficiency Improvement Study
Authors: Henderson A.
Published: August 2023

Investigate the application of techniques which could be used to increase the efficiency of gas turbines applied to gas transmission compression facilities.
PR-179-15212-R01 Methane Reduction Data Analysis for 2-Stroke Lean Burn Natural Gas Engines
Authors: Ladd  , Stevens  , Olsen
Published: August 2023

Existing test data from the Engines and Energy Conversion Laboratory and other sources are analyzed to examine the impact of retrofit technologies and operating parameters on greenhouse gas emissions. CO2, CH4, and CO2e (equivalent CO2) emissions are the focus of the study. The data analysis is focused on 4 main categories, engine performance maps, retrofit technology, uncontrolled parameters, and NOx permit level. Examination of the impact of HP replacement is also performed.
PR-328-153721-R01 Development of an Industry Test Facility and Qualification Process for ILI Technology
Authors: Cazenave Pablo
Published: August 2023

The project "Development of an Industry Test Facility and Qualification Processes for in-line inspection (ILI) technology Evaluation and Enhancements" aims to expand knowledge of ILI technology performance and identify gaps where new technology is needed. Additionally, this project aims to provide a continuing resource for ILI technology developers, researchers and pipeline operators to have access to test samples with a range of pipeline integrity threats and vintages and in-line technology test facilities at the Pipeline Research Council International, Inc. (PRCI) Technology Development and Deployment Center (TDC), a PRCI managed facility available for future industry and PHMSA research projects. An ILI pull test facility was designed and constructed as part of this project based on industry state of the art and opportunities for capability improvement. The major ILI technology provid-ers, together with pipeline operator team members, reviewed the TDC sample inventory and de-signed a series of ILI performance tests illustrating one of multiple possible research objectives, culminating in 16 inch and 24 inch nominal diameter test strings. The ILI technology providers proposed appropriate inspection tools based on limited knowledge of the integrity conditions in the test strings, a series of pull tests of the provided ILI tools were performed and the technology providers delivered reports of integrity anomaly location and physical dimensions for perfor-mance evaluation. PRCI engaged Blade Energy Partners, Ltd. (Blade) to conduct the evaluation of the ILI data obtained from repeated testing on the 16 and 24 inch pipeline strings at the TDC. Blade Energy was also requested by the PRCI Project Team to incorporate prior work concerning the development of the PRCI ILI test facility to serve as a final report for the PRCI project. The resulting data was analyzed, aligned, compared to truth data and evaluated by Blade, with the findings presented in this report. Quantitative measures of detection and sizing performance were disclosed in-confidence to the individual ILI technology providers. For instances where ILI predictions were outside of claimed performance, the vendors were given a limited sample of actual defect data to enable re-analysis, thus demonstrating the potential for improved integrity assessment with validation measurements.

This report has a related webinar.
PR-244-05405-R01 Effectiveness of Prevention Methods for Excavation Damage
Authors: Chen  , Chebaro
Published: August 2023

This report describes the development, validation, and application of a fault tree model that estimates the frequency of mechanical damage events. The intended application of this model is to quantify the effectiveness of damage prevention methods in terms of their potential for reducing impact frequency, and to assist with the selection of damage prevention methods.
L52004 Sizing Stress Corrosion Cracking in Pipeline Specimens from the Outside Surface
Authors: Selby  , Spanner
Published: August 2023

The EPRI NDE Center examined specimens of carbon steel piping containing SCC, distributed by Battelle Columbus on behalf of the Gas Research Institute. Time of Flight Diffraction (TOFD) and phased-array UT techniques were used. The techniques were applied both manually and using an automated data acquisition system. This interim report conveys the results of both techniques. Beginning in 1997, EPRI used TOFD to measure the depth of cracks in three specimens designated for practice. In 1998 and 1999 GRI performed a round-robin test of several candidate crack depth sizing techniques. Each candidate was used to inspect two field removed pipe sections containing SCC. After all the techniques results had been submitted, the two specimens were sectioned to determine the true crack depth of each of the 12 specified measurement locations. EPRI participated in the round-robin using two separate implementations of an advanced ultrasonic technique known as phased array. EPRI and AEA continued to participate in GRIs investigations by applying the techniques to additional SCC specimens provided by GRI in 2000. The results of inspecting the spools were transferred to inspection vendors in May of 2002. This final report provided by EPRI summarizes the results of all of the investigations.
NG-18-105-R01 Evaluate the Susceptibility of High-strength Pipeline Steels to Hydrogen-Stress Cracking
Authors: Groeneveld T. , Elsea A. R.
Published: August 2023

A report that summarizes the field studies conducted as part of the Hydrogren-Stress-Cracking Phase of the NG-18 Research Program. These studies involve the evaluation of the sensitivity of pressurized high-strength steel pipe sections to hydrogen stress cracking under pipeline environmental conditions.
PR-164-9111-R01 Critical Hardness Values for Avoiding Cracking During Welding on Pressurized Pipelines
Authors: Threadgill
Published: August 2023

This is a final project report which documents the attempts to find a field useable hardness tester that could be used to predict the risk of cracking in the heat affected zone. Only one instrument was identified that performed with reasonable consistency. The maximum hardness value below which the researcher considered the risk of cracking to be minimal is provided. The Welding Supervisory Committee is not completely convinced of the validity of that hardness value. Because the report endorses one manufacturer, it is designated for member only use.
GRl-96-0307 Current Market Drivers and Probable Trends in the Utilization of Natural Gas Storage
Authors: Beckman Kenneth , Determeyer Peggy , Mowrey Earle , O'Connor Peter
Published: August 2023

Interest in and demand for natural gas storage services are evolving due to a number of factors, including fundamental market shifts in the demand for natural gas and due to factors such as regulatory changes. The understanding of these shifts is fundamental to GRIs allocation of funding for Research and Development in the area of natural gas storage.

The regional trends and responses regarding present and anticipated natural gas storage requirements closely parallel the historical availability of those services. Respondents in areas of shortage value reliability over cost and respondents in areas of abundant supply value price over other criteria. With projected increases in peak day requirements for most industrial and regional segments, flexibility in storage services will be critical, and a need for cost-effective peaking service is evident. The demand for natural gas storage services will continue to be tailored to specific industrial and regional requirements.
NR196801 Types of Pipe Defects
Authors: Eiber
Published: August 2023

Knowledge of the various types of defects and the examples used, have resulted from failure investigations sponsored in past years by individual pipeline companies and pipe manufacturers. One of the important observations from the examination of leaks or breaks is that, except in a very few cases of gross overload from secondary stresses, there has always been a defect of some type present at the origin of the failure.

This report contains a summary of the various types of defects that have been observed to cause failure in line pipe. The description of defects has been divided into two categories: (a) those in the pipe prior to the test after construction and (b) those introduced into the pipe following the test after construction. The injurious defects in the pipe prior to the pre-service test can be eliminated by the hydrostatic test if the test pressure level is high enough-i.e; any of these defects that remain after a high-pressure test will not be serious enough to produce a leak or break later during service. The one exception to this is the occasional hard spot, which is present in the pipe wall prior to the pre-service test but is not removed by the test--such a defect has been known to later produce a leak or break because of the phenomenon of hydrogen-stress cracking.
L52020 Extension of Strain Design Criteria to Buried HAZ Defects
Authors: Wang  , Cheng
Published: August 2023

This project is a part of a multi-year effort intended to develop alternative defect acceptance criteria for pipelines experiencing high longitudinal strains.� A systematic investigation of various factors affecting the tensile strain limits of buried girth weld defects is conducted.� By using the concept of crack driving and apparent toughness, the baseline tensile strain limits of girth welds with buried defect are established for a wide range of pipe grades, wall thickness, defect size, and material toughness.� The relative influence of various factors affecting the strain limits of girth welds with buried defects is characterized.
L52099 Develop Predictive Accelerated Test Methods for Coatings
Authors: Ruschau
Published: August 2023

The objective of this work was to develop predictive accelerated test methodologies for external pipeline coatings, with a focus on FBE. The test method(s) should not only provide an indication of long term performance of the coating system but should also provide a means of ranking competing candidate coatings under the given test conditions based on realistic test methods, and should provide a quantitative system for rating coatings on a pass/fail basis for qualification purposes.
L52135 Humidity Control for Power and Emissions
Authors: Olsen
Published: August 2023

NOX emissions regulations below 1.0 g/bhp-hr are being implemented in some parts of the country (e.g. Houston). Increasing engine efficiency is one way to increase gas transport. However, a dilemma that often occurs is techniques that reduce NOX emissions often simultaneously decrease engine efficiency.
An alternative approach to increasing gas transport is to increase the power output, or brake mean effective pressure (BMEP), of the large bore natural gas engines presently in service. The onset of knock typically limits the maximum power output of spark ignition engines; water injection can eliminate knock and enable a power increase.

In this work, the feasibility of in-cylinder water injection is demonstrated as a technique for reducing emissions and increasing BMEP. A water injection system was developed for the Cooper-Bessemer GMV-4TF engine. Two locations for water injection were evaluated, near the spark plug and opposite the spark plug in the end gas. Testing was conducted for both NOx reduction and increasing power.
L52031 In-Situ Pipeline Mechanical Property Characterization
Authors: Tiku  , Pussegoda  , Luffman
Published: August 2023

The focus in the present study was to establish whether there is a reasonable correlation between the Charpy Vee Notch (CVN) toughness and the non-destructive Potential Difference (PD) measurements of ferritic-pearlitic steels having a range of CVN toughness values. Complete material characterization was carried out for six steels procured for this program. The characterization included chemical analysis, microstructural information, tensile properties and CVN transition curves. In addition, most of the data including the CVN transition curves were available for five suitable pipe line steels from a recent publication in the literature.
NR198602 Evaluation of an X70 Pipe Fabricated from an Accelerated-Cooled C-Mn-V-Cb Steel
Authors: Williams  , Maxey
Published: August 2023

The demand for high-strength line pipe with good low temperature toughness has resulted in the development of a number of new types of line pipe for gas transmission service. Radically different steel compositions and highly advanced processing methods have been used by pipe producers to satisfy this demand. In 1984, the Pipeline Research Committee initiated a research program to evaluate representative samples of these new pipes.

The objective of this program is to obtain an independent measurement of pipe properties and to examine metallurgical characteristics that may affect the behavior of pipe in gas-transmission service. This report presents the results obtained from the evaluation of anX70 pipe fabricated from an accelerated-cooled C-Mn-V-Cb steel. The present report describes the evaluation of the second line pipe that was examined as part of this program.
NR197903 Examination of the Properties of a Y65 Quenched-and-Tempered Fitting
Authors: Williams
Published: August 2023

�In an earlier study the tensile properties measured with specimens taken from a quenched-and-tempered 30x30x30x0.625-inch Y60 tee manufactured in the mid-1960s were found to be appreciably lower than those reported by the supplier. Also, the impact properties were quite variable as a function of the orientation of the specimens and their location within the fitting. Because this fitting was produced about 15 years ago, it was thought that these observations might not be valid for present-day fittings. To check this, a second fitting, a quenched-and-tempered 24x24x24x0.5-inch Y65 tee manufactured early in 1978 was purchased and subjected to a similar evaluation. This report describes the results obtained from the evaluation of this new fitting.
L52015 Seam Weld Integrity of New High Strength Steels
Authors: Beavers
Published: August 2023

There is a concern that there may be areas of low toughness in the seam welds of submerged arc welded linepipe. These are typically associated with the Coarse Grained Heat Affected Zone (CGHAZ), and manifest themselves through low values obtained in Charpy impact and CTOD tests. Although this problem is not new, there has been renewed concern amongst linepipe users and manufacturers with the introduction of higher strength grades (X80 and upwards).

A study was carried out using typical parameters for X70 and X100 grade material to investigate the structural performance of low toughness seam welds. Two-dimensional elastic T stress solutions for cracked flat strips can be used for constraint based analyses of long axial pipeline defects. Constraint based analysis has predicted the experimental ring tension results in X70 and X100 material with acceptable accuracy. Analysis of a range of surface breaking and buried defects has shown that low toughness levels in the HAZ are unlikely to adversely affect the integrity of high strength linepipe.
L52006 Shape Resolution Accuracy and Calculated Remaining Strength for Corrosion Defect Clusters
Authors: Grant
Published: August 2023

Reliable predictions of the remaining strength of corroded pipelines are dependent on the availability of an accurate description of the defect shape that is detected by in-line inspection (ILI) tools. This is particularly the case for complex shaped defects that are closely spaced. If only the maximum defect dimensions are recorded and subsequently used in a defect assessment then a low remaining strength is likely to be predicted for the corroded pipeline. However, if the defect profile had been more accurately mapped then improved predictions of the remaining strength can be determined from the subsequent defect assessment. This report examines the critical dimensions of metal loss defects that are subsequently used in deterministic assessments.
3DWXATZ Inhibitive Effect of Organics on Near-neutral pH SCC
Authors: Been  , Lu  , King
Published: August 2023

The objectives of the current project are to confirm the earlier observation of an inhibitive effect of organic soils on the stress corrosion cracking of pipeline steels and to determine the mechanism of this inhibition.� Identification of an inhibitor for near-neutral pH SCC that may be naturally present in some locations could perhaps be deliberately added in other locations.
L51435 Gas Expansion Studies
Authors: Maxey
Published: August 2023

The report examines how decompression velocities are determined and indicates the general theory and assumption used. It also presents experimental data relating to special cases of decompression, both single phase and two-phase, that are of interest on gas transmission pipelines. The report concludes that no simple graphical or tabular solution exists for describing the two-phase decompression, but that each design is unique.
L52078 Ambient Temperature Effects on Turbocharger Performance
Authors: Chapman  , Keshavarz  , Johnson
Published: August 2023

The objective of this project was to either validate the current correlations or develop a new correlation that are used to compare compressor maps. Most compressor maps are presented at standard temperature and pressure. In order to compare data that is not collected at these conditions, correlations are used to relate the data to standard conditions. This project analyzes the validity of currently used correlations and provides improved correlations as needed.
L51514 Flow Tolerance of Spiral-Welded Line Pipe
Authors: Kramer  , Wilkowski  , Maxey
Published: August 2023

The goals of this research program were to: (1) assess the mechanical and fracture properties of spiral-welded pipe, (2) characterize the crack initiation and maximum load carrying capacity, and (3) determine stress magnification factors for helical flaws. Flattened-strap tensile tests, Charpy V-notch (CVN) tests, and JIC fracture toughness tests were performed to meet the first objective. Results showed that tensile properties are independent of specimen orientation, while CVN data varied by as much as 3 to 1 for parallel vs. transverse machined specimens. Full-scale pipe fracture experiments were conducted to meet the second and third objectives. Results showed that crack initiation was parallel to the rolling direction regardless of the principle stress direction. Stress magnification factors were also developed for through-wall and surface cracks under longitudinal and circumferential stresses. These factors allow design engineers to predict the critical bending stress, circumferential stress, and flaw size for spiral-welded pipe.
L51857 Evaluation of Digital Image Acquisition and Processing Technologies for Ground Movement Monitoring
Authors: Randell
Published: August 2023

Ground movement may occur due to landslides, seismic activity, adjacent earth works, thaw settlement of permafrost, frost heave, or a variety of other causes. When soil moves relative to a pipeline, loads are imposed on the pipeline that will tend to stress it. Portions of the pipeline are anchored or loaded by the moving soil mass, while adjacent portions are anchored in the intact soil and tend to restrain the pipeline. These soil movements and restraints set up stresses within the pipeline that, depending upon the magnitude of the stresses and the nature of the pipeline, may cause damage or failure of the line.

The objectives of this project were to evaluate and, where appropriate, enhance the ability of satellite-based interferometric synthetic aperture radar (InSAR) and airborne laser range-finding to delineate and monitor slope movements along pipeline right-of-ways. Particular emphasis was placed on operational issues, and especially the problems associated with applying these technologies in areas where natural vegetation precludes a straightforward analysis.
GRI-00-8717 Effect of Soil Constituents on Near Neutral pH SCC Propagation
Authors: Beavers  , Gerst
Published: August 2023

The objectives of the research were to verify the preliminary observation from the previous TCPL research that some soils contain constituents that promote near-neutral pH SCC and to identify possible constituents.

Crack growth tests were performed on samples of susceptible line pipe steel in two of the most potent cracking soils from a previous research project performed for TransCanada Pipelines, followed by analyses of the soil/electrolyte environments at the completion of the tests.� Corrosion potential and corrosion rate measurements also were performed on specimens of the line pipe steel in the electrolytes.
L52005 Reliable Diagnosis of SCC During Field Inspection
Authors: Duncan
Published: August 2023

Direct assessment (DA) is one method pipeline companies use to assess the extent and severity of stress corrosion cracking and other defects on their pipeline system. Successful integrity management of a pipeline is dependent, in part, on proper interpretation of the defects encountered in the DA program. The objective of this project was to prepare a document containing a compilation of types of crack-like magnetic-particle testing (MT) or visual indications found on underground transmission pipelines for the purpose of proper interpretation of their type and cause. Pipe samples containing various types of defects were inspected by means of black and MT, optically photographed, and then metallographically sectioned and photographed. The MT photographs and metallographic photomicrographs were compiled in an Access Database.
L51966 Correlation of Soil Conditions and SCC Initiation Phenomena to Microbial Induced Corrosion
Authors: Jack
Published: August 2023

This study builds on past work �The Role of Redox and Corrosion Potentials in the Corrosion of Line Pipe Steel� (PR 261-9711) that investigated conditions associated with external corrosion on pipelines. This report specifically assesses the effect of prior exposure to microbially active soils on the initiation of near neutral pH stress corrosion cracking (SCC) in line pipe steel and corrosion rates for line pipe steel in microbiologically active soils under various conditions.
L51976 Critical Assessment of the Remaining Strength of Corroded Pipe Using MFL Signals
Authors: Crouch  , Smith
Published: August 2023

This report covers experimental work done to investigate the use of magnetic flux leakage signals from in-line inspection for measuring biaxial stress in the pipe wall. Test results show that the ratio of lowfield signals to high-field signals correlates well with the difference between axial and hoop stress. If data from pressure transducers are available, the hoop component can be backed out, leaving a good estimate of axial stress. Also in the report is a detailed discussion of the development and validation of a corrosion assessment method, SAFEGTI, that uses the MFL data and produces an estimate of failure pressure which is more accurate and less conservative than the other commonly used algorithms for biaxially loaded pipelines. Axial loading may occur from subsidence, land shifts, or from thermal effects.
L51973 Encroachment Monitoring Via Earth Observation Data
Authors: Mchugh  , Power  , Randell
Published: August 2023

The objective of the pipeline encroachment monitoring was to demonstrate the feasibility of using
earth observation (EO) satellites for early detection of third party encroachment activities.
Examples of encroachment activities include road construction, cable laying, farming, and
residential or commercial development. Such activities may not occur directly on the pipeline
right-of-way, but the associated heavy equipment may drive over the pipeline.