bluuebunny/crossref_metadata_2025 huggingface dataset:
L51971 Coating Gap Analysis
Authors: Papavinasam  , Revie
Published: August 2023

Using an online survey that was completed by 58 persons from around the globe, the gaps have been identified in knowledge and operational expectations of coatings presently in service, as well as of coatings that may be under consideration for future service.

A database of about 500 references on pipeline coatings has been developed in Reference Manager(R) based on published literature and on a search of records. In order to facilitate transfer of data from Reference Manager(R) to MS ACCESS(R), another widely used software package, a program has been written using Visual Basic. Using this program, all databases (including those developed in previous GRI projects) in Reference Manager(R), can be converted into MS ACCESS(R). Based on the comparison between practical requirements and scientific knowledge, action plans for filling the gaps have been prioritized. The prioritized list and the rationale for the prioritization are described in this report.
L52040 The Mechanisms of High-pH and Near-Neutral pH SCC-Unresolved Issues and Experimental Techniques
Authors: Fessler
Published: August 2023

Key unresolved issues related to the mechanisms of high-pH and near-neutral-pH stress-corrosion cracking (SCC) were identified based upon a review of the technical literature. It was determined that the mechanism of high-pH SCC is well understood, the key outstanding issue being related to the factors that affect the micro-creep properties of a steel, which seem to be the primary determinant of its susceptibility to SCC. The mechanism of near-neutral-pH SCC is not so well understood. Both dissolution and hydrogen appear to be involved, but their relative roles remain to be determined. Some experimental methods that have been used to study near-neutral-pH SCC may have produced misleading results, in that they may have introduced other failure mechanisms such as corrosion fatigue or hydrogen embrittlement, which would not be expected under normal operating conditions for a gas pipeline. Additional research into the liquid environment responsible for near-neutral-pH SCC, the time dependence of crack growth rates, and metallurgical factors influencing the susceptibility of a steel would be useful.
L41016 Helium-Bearing Natural Gases Of The United States Analyses And Analytical Methods
Authors: Beavers  , Parkins
Published: August 2023

The primary purpose of the report is to present the results of this work in tabulated form. A secondary purpose is to make public the historical background of the helium survey and to describe the methods of collecting gas samples and them. Detailed descriptions are given of the analytical equipment and procedures used in making the analyses.
L51768 Pipeline Free Span Design-Volume 1 Design Guideline
Authors: Kirk
Published: August 2023

Vol. 1, Design Guideline

The first phase of the project was dedicated to the testing and calibration of a numerical model. The model is capable of predicting the dynamic cross-flow response of a pipeline span caused by vortex shedding. The numerical model was originally developed by Exxon Production Research Co. (EPRCo), Lambrakos (1991) and has been made available to the project. This project results in minimization of intervention work in relation to submarine pipeline design without jeopardizing pipeline safety. The main objective of the Guideline is to present procedures and methodologies for evaluating free spans in submarine pipeline systems. The Guideline addresses specifically vortex-induced vibrations caused by wave and current action. A force model describing the cyclic lift force generated by vortex shedding has been tested and calibrated as part of the Guideline preparation work. This model is adequate to use for calculating the hydrodynamic response of a free spanning pipeline.

Vol. 2, Software and User Guide

The second phase of the project concentrated on the development of the Guideline document itself and the associated software and how to operate the software, FREESPAN, used for assessing free spanning submarine pipelines.

�
L51572 Demonstration of Realtime Radiography on Pipeline Girth Welds
Authors: Light
Published: August 2023

Conventional radiography has been the accepted nondestructive testing (NDT) method used for many years to either accept or reject a field weld in the pipeline industry. However, conventional radiography requires the expense of film, developing chemicals, and manpower for film development. It also normally has a delay of 2 hours or more between when the weld was radiographed and when the radiographic film of the weld is available for interpretation. Over the last few years, a newer approach to performing radiographic testing, called real-time radiography, has been used in several different types of field inspection operations. The real-time radiography system forms the image with optical imaging in lieu of photographic film.

The objectives of this project were to (1) Integrate various optimized real-time radiographic components (identified as a result of the previous project) into a field-usable, real-time-radiographic inspection (RTRI) system for single-wall inspection of pipeline girth welds and (2) Demonstrate the system in the field.
L52022 Validation of Current Approaches for Girth Weld Defect Sizing Accuracy
Authors: Lozev
Published: August 2023

Computational tools based on probabilistic fracture mechanics have been developed to enable reliability-based fitness-for-service assessments of flawed girth welds. The same tools are readily adapted for establishing maximum allowable defect sizes to achieve targeted weld reliability. Sensitivity studies have shown that of the various input parameter uncertainties, measured defect height often has the greatest impact on the probabilities of both fracture and plastic collapse. A reduction in sizing uncertainty should thus dramatically improve predicted reliabilities. The increasing use of mechanized ultrasonic testing (UT) in pipeline construction, driven by the demands of engineering critical assessment (ECA) -based acceptance criteria, highlights the need to quantify this uncertainty, particularly for systems incorporating pulse-echo (P/E) and time-of-flight diffraction (TOFD) methods and phased-array (PA) technology.

EWI collected third-party independent data and statistically characterized the systematic and random errors in girth weld defect sizing, as measured by mechanized UT using P/E and TOFD methods, as well as PA ultrasonic technology, in support of pipeline reliability assessments.
L22277 Retrograde Condensation in Natural Gas Pipelines
Authors: Bergman  , Tek  , Katz
Published: August 2023

The natural gas pipeline industry had an increasing number of interruptions or interference of flow by natural gas due to the presence of condensates in the pipelines. Frequently the customer or the distributing pipeline operating at lower pressures is the recipient of the liquid condensate reaching them sometime in the late fall or winter during a period of high demand for natural gas. This project investigated the causes of the formation of liquid hydrocarbons, ways to predict when condensates will form, and preferred methods of condensate removal when formed inadvertently.
L00972 Magnetic Flux Leakage of Small Defects in Line Pipe
Authors: Robichaud
Published: August 2023

It is the purpose of this project to evaluate the MFL technique in detecting pipeline defects. This involves obtaining data on the leakage fields produced by a wide variety of defects and evaluating the effects of uncontrolled variables that may affect the leakage field. The program was divided in two parts, program 1 and program 2. Program 2 was completed first. Its main objective was to develop a method to calculate the MFL for defects common to buried pipelines. To accomplish this, a series of Fortran time-sharing computer programs were written to model the MFL phenomena. The programs can model the MFL produced by inclusions, voids, cracks, corrosion and hard spots, the computer programs were verified successfully by comparing experimental MFL signature to the results obtained using the computer model.
L01972 Calculation of Field Due to a Reluctance Variation Zone
Authors: Robichaud
Published: August 2023

A library of Fortran time sharing computer programs was written to model the magnetic field of the magnetic flux leakage technique. The model is two-dimensional and assumes linearity. Solution of the field is achieved through the iterative relaxation method.

Leakage fields of interest are those produced by defects within pipeline walls such as inclusions, voids, cracks, corrosion and hard spot. The programs can model the field produced by any of the above defects, both within the plate and in the surrounding airspace. The information obtained using this model will then be used to evaluate the magnetic leakage field technique in detecting pipeline wall defects.
L52090 Near-Neutral pH SCC - Dormancy and Re-Initiation of Stress Corrosion Cracks
Authors: Bruce
Published: August 2023

The objective of this research project was to identify the environmental, metallurgical, and mechanical conditions that lead to dormancy and re-initiation of previously dormant stress corrosion cracks. These parameters would assist pipeline operators in mitigating near-neutral pH SCC on their systems, and allocating resources for pipeline maintenance.

Unload-reload transients were found to increase the crack growth rate in the majority of the experiments and to re-initiate dormant stress corrosion cracks in several cases. On the other hand, there was no consistent effect of the presence or magnitude of overloads on crack growth behavior. The simulated hydrostatic tests had relatively little effect on the crack velocities for near dormant conditions, but consistently inhibited subsequent crack growth for actively growing cracks.

The results of analyses of the data and modeling suggest that the R ratio (ratio of minimum to maximum pressure) and frequency of pressure fluctuations on an operating pipeline can be used as a tool to rank segments of pipelines base on the mechanical driving force for propagation of near neutral pH SCC. The concept of a critical crack tip strain rate, which can be related to the R ratio and frequency, also can be used to reasonably predict whether a given set of loading conditions will lead to dormancy.
L52203 Internal Corrosion Direct Assessment of Gas Transmission and Storage Lines
Authors: Sridhar
Published: August 2023

Internal corrosion occurs where water or other corrosive electrolyte accumulates. This is the principle used in Internal Corrosion Direct Assessment (ICDA). The objective of the project is to perform field validation of the dry gas ICDA methodology and develop a wet gas ICDA methodology. The project showed that the principle of the dry-gas ICDA methodology is valid However, many uncertainties remain both in data collection as well as detailed examination. The data and model uncertainties were addressed using a probabilistic method, combined with field data using a Bayesian updating method. An approach to wet gas ICDA was indicated, but further validation was not within the scope of this project.
L51400 Detection of Internal Undercut in Pipeline Girth Welds
Authors: Macecek M
Published: August 2023

Nondestructive testing measurements of the depth of internal undercut in pipeline girth welds. The incidence of internal undercut results in severe economic penalties during the construction and operation of pipelines. There are three phases of the effort documented in this zip file.
CWI1988-Andi-16 Neutron Diffraction of Axial Residual Strains Near a Crack in a Girth Weld
Authors: Holden T. , Root J. , Hosbons R.
Published: August 2023

The purpose of the present measurements was to measure the axial residual strains at the 6:00 position of a girth-weld in the presence of a crack which had been propagated a few millimeters from the inside diameter of the line pipe. Residual strains have been measured in the axial direction of a cracked girth weld in a line pipe. The crack was approximately 3 mm deep and ran 20 cm around the circumference near the mid weld. The residual strain distribution was compared to the distribution before the crack was introduced. The crack appears to introduce a large bending moment in the weld and the strain distribution shows that the tube is close to plastic collapse.
CWI1988-Andi-12 Neutron Diffraction of Axial Residual Strains in the Vicinity of a Girth Weld
Authors: Holden T. , Root J. , Hosbons R.
Published: August 2023

Recent research has shown that neutron diffraction is a practical non-destructive method for determining residual strains in the vicinity of a girth weld in line pipe. The basis of the technique is that the distance between planes of atoms is used as a miniature, directional, internal strain gauge, just as for X-ray measurements. However, the penetration of neutrons into metals ls from 1000 to 10,000 times greater than that of X-rays, so that measurements may easily be made throughout the thickness of steel pipe including the region of the weld itself.

The purpose of the present measurements was to characterize the axial residual strains remaining in linepipe after two pieces had been joined with a girth weld. This report summarizes the measurements of the axial residual strains in each of two pipes of thickness 11 and 16 mm at the 6:00, 1:30 and 10:00 positions.
L51472 Effects of SNG-Hydrogen Gas Mixtures on High Pressure Pipelines
Authors: Holbrook J. , Cialone H.
Published: August 2023

Evaluates the effect of the introduction of hydrogen operating at high pressures on the mechanical properties of line pipe.
PR-457-14201-R03 Variable NG Composition Effects in LB 2S Compressor Engines - Prediction Enhancement
Authors: Jacobs Timothy , Hedrick Jacob
Published: August 2023

Phase II of the project has focused on improving the initial analysis performed in the first phase by enhancing the various aspects of predictive combustion for lean burn spark ignition natural gas engines under variable composition fueling. These enhancements have incorporated validation data from a Cooper-Bessemer GMVH-10C3 engine located in New Jersey, which improves upon the lack of field data to bound the scope of composition variation. In simulation related endeavors, effort was made to improve the fundamental combustion physics related parameters, namely laminar flame speed, by developing a code base for distributed computing of the chemical kinetics solver, Cantera, and was key to improving upon the chemistry modeling used in the previous phase. Methods to improve numerical convergence were employed to reduce the time to solve large mechanisms, such as the Saudi Aramco Mechanism (v1.3).

Modeling of pre-chamber combustion from first principles, common input experimental heat release analysis and simulated heat release generation were additional components of improving model matching with pre-chambered engines. In its current state, manual optimization is required to tune the heat release curves based on guesses about the initial charge mass state, scavenging efficiency, fuel delivery and thereby the trapped equivalence ratio.
NR199002 Monitoring Hydrogen Cracking in Sleeve Welds
Authors: Balda S.
Published: August 2023

The objective of this work was to determine the time interval for hydrogen induced cracking in hot tap/sleeve maintenance welding by using pipe/consumable combinations known to produce hydrogen induced cracking.
L51540 Corrosion Criteria for J-Tube Risers
Authors: Coiwell J. , Pednekar S. , Han M.
Published: August 2023

The state-of-the-art survey showed that a number of risers have been installed, using the J-tube method, in a variety of water depths and in a range of diameters. Many different coating types have been used, but neoprene appears to be the most popular. There was one reported riser failure after 10 years of service that was attributed to a damaged coating and an improperly set bottom plug. In the experimental program, two coating types were used, and the riser pipes were pulled through the 3-tube test stand that was constructed in Houston; these were a two-part urethane and 1/2-inch thick neoprene. The use of inhibitors was also studied.
PR-3-122-R01 Crack Detection Sensors During Welding
Authors: Findlan Shane , Hyatt Roger
Published: August 2023

The objective of this research was to demonstrate through a laboratory simulation that acoustic emission techniques could be used to detect the occurrence of cracking during the welding of girth joints in gas transmission pipelines.
TAPS-5096 Mitigation of External Corrosion of a Buried Pipeline with Pulsed Cathodic Protection
Authors: Chin D. , Sabde G. , Sun Z-W
Published: August 2023

This report describes a study to determine the feasibility of using an external power source to cathodically protect the pipe surface beneath a disbonded coating. The relative advantages of using a pulsed current versus those of a direct current power supply were experimentally examined. Two main tasks were carried out during the project period; they were: i) a cathodic protection screening study using a small laboratory cell filled with either 0.6 M NaC solution or Atigun Valley ground water and ii) a cathodic protection test of a steel pipe buried in Atigun Valley soil. The second task simulated the field conditions of the Trans-Alaska Pipeline (TAPS) in the Atigun Valley Pass. These experiments were supplemented by four supporting tasks including: a literature review on the state-of-an of the cathodic protection technology for underground pipelines in high resistivity soils; potential measurements with a model crevice cell to simulate the disbonded coating with a holiday; polarization measurements of a TAPS steel coupon in neutral aqueous solutions; and electrochemical characterization of the polyethylene tapes used on the Trans-Alaska Pipeline.

Reference material only, not a PRCI related research project.
PR-430-133757-R01 PHMSA Comprehensive Study to Understand Longitudinal ERW Seam Failures
Authors: Mittelstadt Benjamin
Published: August 2023

In 2011, the US Department of Transportation (DOT) Pipeline and Hazardous Materials Safety Administration (PHMSA) initiated a project known as the "Comprehensive Study to Understand Longitudinal ERW Seam Failures" (PHMSA Phase 1 ERW Study). The project deliverables were thirteen (13) individual 'task reports' and a summary report which included considerations for failure history, characteristics of ERW seams that make them susceptible to failure, fracture mechanics and fatigue models, selective seam weld corrosion, integrity assessment, and non-destructive examination (NDE) methods. As of the development of this report, a second phase of the PHMSA research program is now under way including full scale testing and validation of integrity assessment and NDE methods.

This report is a summary of an industry critical review performed by several representative PRCI member companies of the PHMSA Phase 1 ERW Study. It is recognized that a second phase of the research is currently under way by PHMSA, however PRCI's member companies wanted to review and capitalize on relevant information and data presented in the current body of knowledge. Ultimately, this and other work performed throughout the industry will provide the foundation for developing and validating integrity management programs for pipelines constructed of vintage ERW line pipe.
PR-201-163707-R01 Effectiveness of Low Field MFL Technology Measuring Loading at Branch Connections
Authors: Vyvial Brent
Published: August 2023

Unsupported branch connections or branch connections under loads due to unstable support conditions are an integrity threat and potential failure location in pipelines. No industry accepted method currently exists to assist operators in identifying problematic branch connections in a measurably-reliable way. Low field magnetic flux leakage (LF-MFL) offers one potential method to identify stressed sections of pipeline. The purpose of this project was to evaluate the ability of LF-MFL in-line inspection (ILI) technology to characterize loading conditions around branch connections and to validate the use of LF-MFL ILI to identify stressed branch connections. The results of this work will provide operators with guidance for using LF-MFL ILI tools to identify integrity threats.
PR-15-9222-R01 Gas Scrubber Performance Evaluation
Authors: Svedeman Steven
Published: August 2023

The objectives of this work was to determine scrubber performance requirements and to identify candidate instrumentation and test methods for scrubber performance testing. Included in this report are the gas cleaning requirements needed to provide proper compressor operation, minimize metering device inaccuracy, and limit emissions from vent and blow down lines.
NG-18-R03 Analysis of Impact-Test Results
Authors: W C. , Bert  , McClure G. M. , Grover H. J.
Published: August 2023

Evaluates the impact of carbon content with respect to the API-5LX52 specification.
PR-180-524-R01 Generation and Disposal of Oily Waste from Natural Gas Transportation Facilities
Authors: Unknown Author
Published: August 2023

Evaluates (1) the generation and disposal of used oil and oily waste at natural gas transportation facilities, and (2) the existing and anticipated regulations for their impact on handling these wastes.
PR-350-114511-R02 Refined Methodology for Assessment of Weld High-Low Misalignment Phase 2
Authors: Wang Yong-Yi , Kotian Kunal , Jia Dan
Published: August 2023

High-low misalignment in girth welds introduces local bending stress and thus can potentially have detrimental effects on the load capacity of girth welds. However, long-term pipeline service experience demonstrates that pipelines can survive a large degree of high-low misalignment without an appreciably negative impact on the safety and integrity of the pipeline. This project is intended to understand the effects of misalignment on the performance of girth welds.

Under Phase 1 (preceding phase) of this project, the effect of weld high-low misalignment on nominally defect-free girth welds was investigated. In this Phase 2 work, the focus is on understanding the influence of high-low misalignment on the stress capacity of girth welds with planar flaws.

From the work so far, it appears that moderate levels of high-low misalignment, approximately 1/3 of pipe wall thickness, can be permitted without a negative impact on the stress capacity of girth welds, provided certain quality control measures are taken, such as ensuring a smooth weld transition profile and minimizing the propensity of hydrogen assisted cracking. The work done in Phases 1 and 2 also provides a foundation for the follow-on work in Phases 3 and 4 of this project, which focus on drafting code-ready recommendations and communicating the recommendations to the standards committees.
PR-420-153722-R01 Pipeline Right-of-Way Ground Movement Monitoring from InSAR
Authors: Robert Gillian
Published: August 2023

Longwall mining induces large surface motion that may impact active pipelines. Typical remediation for longwall mining involves shutting down and exposing the pipeline. The use of InSAR has the potential to provide accurate measurements confirming the expected ground movement that will occur with the mining operations. Used correctly, with an appropriate survey design, InSAR can provide extremely high densities of ground movement over time. Exploiting the wide-area capabilities of InSAR could become an important part of integrity management for pipelines where longwall mining is a consideration.

InSAR surveys are well suited to the observation of spatially and temporally smooth movements. These movements can be very small (millimetres in months) or larger in areal extent and movement. We have previously shown the ground movement (of 9.8 ft in 12 years) along a pipeline associated with an enhance oil recovery operation.

This work examines some of the design considerations necessary to observe fast, large scale deformation with InSAR. This is accomplished through modelling and through the examination of data captured over a pipeline/longwall mine in Pennsylvania. The qualitative description of the passage of the miner is very good. The local ground conditions in Pennsylvania make a more thorough examination of the ground movement available from SAR less accurate than it would be in regions better suited to InSAR measurements (for instance Wyoming).
PR-363-17602-R02 Gap Analysis in Liquid Volume Proving Methods
Authors: Robson Brendan
Published: August 2023

The overall aim of the project is to identify the best practices in measurement system design and proving procedures in order to reduce measurement uncertainty. This is in recognition that improvements made to the calibration of flow meters would have a direct correlation in reducing system measurement uncertainty, improving overall pipeline balancing, and, amongst other benefits, reducing the minimum detection thresholds of leak detection systems.

The project includes an extensive literature review of proving practices, standards, developments and case studies. This was balanced by an industrial survey which collected views, experiences and priorities. A gap analysis was then conducted on the literature and survey results to meet the project's recommendations on areas of improvement and derived priorities.

The proving of ultrasonic and Coriolis flow meters requires special attention. By analyzing the existing literature, the project considers such concerns and presents suggestions for these devices in particular.

This report has a related webinar.
PR-218-104509-R02 Field Validation of Surface Loading Stress Calculations for Buried Pipelines Milestone 2
Authors: Zand Benjamin
Published: August 2023

In this work, the Canadian Energy Pipeline Association (CEPA) equation for prediction of hoop stress in a buried pipeline was validated using the Milestone 1 experimental data. The Milestone 1 testing program included a 24-inch outside diameter (OD), 0.25-inch wall thickness (WT) pipe specimen in sand (24-inch Sand); a 12.75-inch OD, 0.5-inch WT pipe specimen in clay (12-inch Packed Clay); and a 24-inch OD, 0.25-inch WT pipe specimen in clay (24-inch Dumped Clay). Two different depths of cover (DOC) values of 2 and 3 feet were used in the testing and the test specimens were crossed by a variety of construction equipment, namely a dump truck, a bulldozer, a front loader, and a vibratory compactor. The testing was conducted at internal pipe pressures of zero, 550 and 750 psig.
PR-616-164506-R01 Management of Geohazards Affecting Engineering and Construction of Pipelines
Authors: Sancio Rodolfo
Published: August 2023

The available literature includes numerous publications describing approaches, methods, and recommendations, for identifying, characterizing, and mitigating geohazards, as well and case histories of pipelines affected by geohazards and how their effects were mitigated. However, these publications are not comprehensive; separately provide information for identification, characterization, and mitigation; do not include all geohazards affecting pipelines; or may not have been developed specifically for pipelines.

PRCI identified this gap and commissioned the development of a guidance document to succinctly incorporate geohazard management guidance into a single volume addressing i) the types of geo-hazards affecting pipelines, ii) the typical process used in practice to identify and characterize geohazards throughout the various project stages, iii) the techniques used to mitigate the geohazards, and iv) the approaches and methods recommended to project teams of owners, operators, engineers, and contractors to successfully execute projects. The guidance document is intended for a wide audience that includes technical and nontechnical managers at companies owning and operating pipelines, geoscience and engineering teams involved in studying and assessing pipeline integrity hazards, and construction staff, regulators, lenders, and other stakeholders involved in executing pipeline projects.
PR-015-153602-R01 Vapor Corrosion Inhibitors Effectiveness for Tank Bottom Plate Corrosion Control
Authors: Shukla Pavan , He Xihua , Pensado Osvaldo , Nordquist Andrew
Published: August 2023

Soil side corrosion of the above ground storage tanks bottoms is a major challenge for the midstream operators owning tanks farms. In North America subcontinent, a large fraction of tanks are installed with an active cathodic protection (CP) system to protect the tank bottom from corrosion. However, CP systems could fail, and sometime even with the CP system, corrosion can occur. In addition, several tanks without CP system could experience elevated corrosion including pitting corrosion. Vapor corrosion inhibitors (VCIs) are being promoted as alternative corrosion control measures in addition to the CP. This study was conducted to determine whether the VCIs are effective in mitigating corrosion to a level comparable to a working CP for tank bottoms, what is the best way to monitor efficacy of VCIs, and whether the VCIs compatible with CP or not. Extensive amount of laboratory scale and limited field testing was conducted. Both laboratory and field data were rigorously analyzed. It was found that the VCIs are effective in mitigating corrosion when vendor specific recommended dosages are used, and the electrical-resistance based corrosion rate monitoring technique does show the effect of VCIs. Regarding VCI and CP compatibility, VCIs indirectly affect the CP as exposure of tank bottom steel to VCIs change its native potential which in turn changes the CP current demand. Overall, VCIs were found to be a viable alternative corrosion control measure.
PR-312-16202-R02 GHG Emission Factor Development for Natural Gas Compressors
Authors: Coulson Wendy , McCarthy James
Published: August 2023

The U.S. EPA Greenhouse Gas (GHG) Reporting Program (GHGRP) requires compressor stations and underground storage facilities to measure compressor vent, rod packing, and seal emissions for facilities subject to 40 CFR, Part 98, Subpart W. The objective of the project is to gather and evaluate 2011 - 2016 Subpart W compressor vent and seal methane emissions data from site measurements, and present final results of an analysis to develop methane Emission Factors (EFs) based on these data. The EFs and analysis of relative contribution from different sources can be used: (1) as alternatives to current emission factors for compressor methane emissions used for Transmission and Storage (T and S) operations in EPA's annual GHG inventory; (2) to provide an EF based emission estimate for Subpart W that replaces ongoing annual GHGRP vent measurements; and (3) to document the relative contribution of different compressor leak/seal sources and support alternative leak mitigation strategies. Comparisons of the EPA Annual GHG Inventory EFs to Subpart W based EFs in this report show consistently lower compressor emissions than estimates based on historical data or reports. Large leaks, which stem from less than 3% of the compressor measurements, increase the EFs by 26% to 194%, thus greatly impacting the EF results. Alternative EFs are provided for transmission and storage compressor methane emissions.
PR-003-063509-R01 Models for Predicting Delayed Fatigue Failure of Pipelines at Mechanical Damage
Authors: Leis Brian , Zhu Xian-Kui
Published: August 2023

Because where potentially serious damage is found it is dug and dealt with, models that assess damage severity have no relevance in that context. But, as in-line inspection tools become better adept in identifying and characterizing potential damage, models will be needed to screen the ILI results, to determine whether a dig is warranted, and when that must happen. While criteria like B31G might be used to assess metal loss due to a gouge, the usual complexity of mechanical damage cannot be assessed simply in terms of length and depth, so validated models that can account for the complexity are required. Such models could then be evaluated parametrically to develop prioritization guidelines useful with modern inspection technologies.

PRCI Projects MD-4-3 and MD-4-4 were initiated to develop such models, with the results of full-scale testing generated in Project MD-4-1 serving as the basis to assess their validity. This report presents the work done as part of PRCI Project MD-4-4, which targeted an improved model for predicting time and/or cycle-dependent failure of dent and gouge damage. In addition to meeting that objective, this project also developed the basis to predict immediate failure consistent with the scope of Project MD-4-1, which as of this reporting had not emerged from the work of Project MD-4-3. Technology framed in the context of PR3-9305 was used to predict the immediate failure due to burst testing of gouged pipe done as part of MD-4-1, and found to accurately predict those collapse-controlled failures. Technology framed in that same context also was used to predict the delayed failure due to fatigue that developed in cyclic pressure testing of gouged pipes that also was done as part of MD-4-1, and found to reasonably predict those outcomes. However, there were some results that indicated the need to better quantify the crack driving force in terms of re-rounding, and the population of defects that can develop when the damaged pipe re-rounds in the wake of damage.
PR-334-174504-R01 Suitability of Line Pipe Materials for Sour Service Literature Research Summary
Authors: Hill Richard , Molinari Aquiles Perez
Published: August 2023

Literature search focused on contributing factors for the appearance of near surface hard zones in line pipe steels manufactured using TMCP plate has been developed. Additional literature search was conducted on the influence of near surface hard zones on sulfide stress cracking of line pipe steels manufactured using TMCP plate.

It can be inferred from the collective research evaluated that the chemical composition, rolling temperatures, scale formation during hot rolling and the accelerated cooling process contribute to the likelihood of forming near surface hard zones in TMCP plates used for LSAW line pipe.
PR-201-164502-R01 Study to Evaluate Delamination and Disbonding of Composite Repairs
Authors: Sheets Colton , Vyvial Brent
Published: August 2023

Composite reinforcement systems have seen extensive use in the pipeline industry over the last two decades as solutions to address a range of pipeline integrity threats. Despite their widespread use, few options exist for reliable inspection of installed composite reinforcement systems. Additionally, there is a lack of well-defined criteria for acceptable flaw types and sizes when found during inspection of the composite repairs. The purpose of this study was to provide information regarding the current state of available composite inspection techniques as well as the impact of delamination and disbondment defects on the performance of composite repairs. The results of the work will provide operators with guidance on using inspection technologies to assess the integrity of installed composite repair systems.

This report has a related webinar.
PR-306-16602-R01 Effect of Calibration Gas Blend on Chromatograph Accuracy
Authors: VATIN Alice , COURTOIS Yann , Fabre Jean-Luc
Published: August 2023

This report describes the tests results carried out on five natural gas gross calorific value analyzers depending on the calibration model. Three analyzers were conventional gas chromatographs. Two analyzers were new generation gas chromatographs. Twenty-three gas blend were used for this study including three calibration gas blend. Therefore, the report enables the most suitable linear calibration model to be chosen, in order to minimize gross calorific value measurement errors with respect to methods.
PR-283-16201-R01 Improved SoLoNOx Taurus 60 Control Algorithm to Reduce Part Load Emissions
Authors: Cowell Luke , Camou Alejandro , Carlos Ivan , Truesdel Dustin
Published: August 2023

An executed NDA is required from Solar Turbines to have access to this document.

The low load control algorithm for Solar Turbines' TaurusTM 60-7802S has been modified and evaluated in a field trial at the TransCanada Glenville Compressor Station. The algorithm has been modified to extend the bleed valve operating range to lower engine speed settings covering operation from idle to 50% load. The pilot fuel schedule has also been optimized with the new bleed valve schedule. The new control algorithm is designated as Enhanced Emissions Control (EEC).

A Mobile Emissions Lab (MEL) and three site visits for extensive low load emissions mapping were used to document the emissions performance of the test unit over 20 months from August 2016 to April 2018. Data was collected over a wide ambient temperature range from -7 to 97 �F.

The field trial has demonstrated that the new algorithm results in a significant reduction in NOx, CO and UHC emissions from idle to 50% load. Reductions in CO and UHC emission of 35 to 99% were demonstrated from idle to 50% load. NOx emissions reductions were slightly less ranging from 50 to 20% from idle to 50% load, respectively. The emissions performance above 50% load were unchanged when comparing the EEC to the production algorithm. Continuous emission measurements indicate that emissions of NOx and CO above 50% load were very consistent with average levels of 10 and 2 ppm, respectively. No clear emission variation trends were evident with ambient temperature or engine speed (load). By extending the load range with temperature control, by modulating the bleed valve, the engine heat rate was increased slightly from idle to 50% load. No measurable impact on heat rate was detected from 50 to 100% load. An improved BAM 2.0 with Active Control was included in the field trial. The BAM 2.0 demonstrated reliable performance and hardware durability over the test period. The Active Control also performed as designed to modulate the pilot fuel flow to maintain combustion stability as required, typically at cold ambient conditions with no measurable effect on emissions.
PR-185-173600-R01 Reference Stress for Metal-loss Assessment of Pipelines
Authors: Zhu Xian-Kui , Leis Brian , McGaughy Tom
Published: August 2023

This project focused on quantifying the reference stress to be used in predictive models for assessing the effects of metal loss on pipeline integrity. The results of this project will work in concert with the outcomes of project EC-2-7 that examined sources of scatter in metal-loss predictions with respect to the metal-loss defect geometry. The methodology for developing a new reference stress included empirical and finite element analyses along with comparison of full-scale experimental results that indicate the failure behavior of defect-free pipe has dependence on the strain hardening rate, n, of the pipe steel. Since the strain hardening rate is often unreported in qualification test records and mill certification reports, the development of a new reference stress will seek to include the utilization of the ratio of yield-to-tensile strength (Y/T) as a surrogate for n. This approach ideally would be insensitive to pipe grade, and thus, allow broad application of the reference stress without increasing scatter or bias across grade levels.

This work also compared the resulting metal-loss criterion with the new reference stress relative to the B31G and Modified B31G models using a dataset of approximately 75 full-scale burst test results for test vessels containing isolated defects. This comparison was performed by C-FER Technologies under sub-contract to EWI and quantified the prediction bias and prediction variability of the new criterion relative to those widely in use.
GRI-03-0083 NO2 Emissions from 2SC Large Bore Natural Gas Engines
Authors: Tassitano Jim , Olsen Daniel , Mitchell Charles , Willson Bryan
Published: August 2023

NO2 emissions data from previous EECL projects on a large bore, slow speed, two-stroke lean burn engine is reanalyzed, looking at the effect of engine variables on the formation of NO2. Included are variations of operating conditions, fuel delivery, and ignition systems. By looking at the emission trends found in the data, techniques may be proposed for the reduction of NO2 emissions. An investigation into the effectiveness of catalysts on NO2 emissions is performed using data taken from previous testing on a medium bore, high speed, four-stroke lean burn engine. A summation of the current understanding of NO2 formation is also included. This is done through a thorough literature review. A chemical kinetics study was carried out through the use of the Chemkin 3.7 program suite. Kinetics simulations were performed to analyze EECL data and locate possible sources of NO2 in the engine.
PR-214-114500-R01 Fatigue Life Assessment of Dents with and without Interacting Features
Authors: Tiku Sanjay , Eshraghi Amin , Dinovitzer Aaron , Rana Arnav
Published: August 2023

The long-term integrity of a dented pipeline segment is a complex function of a variety of parameters, including pipe geometry, indenter shape, dent depth, indenter support, pressure history at and following indentation. In order to estimate the safe remaining operational life of a dented pipeline, all of these factors must be accounted for in the assessment.

The current project provides pipeline operators with a methodology for assessing and managing dent fatigue, thus making it possible to prioritize response and remedial action(s) in an informed manner. The methodology allows the users to carry out dent ranking/prioritization and dent fatigue life assessment. In addition to the development of the plain dent fatigue life assessment methodology, dent weld and dent metal loss interaction criteria have been developed to ascertain their effect on the fatigue life of a dent.

The dent assessment methodology utilizes dent shape information that can be derived from in-line inspection (ILI) data, operating pressure spectra and pipeline material grade. A three-level approach has been developed for assessing the fatigue life or cyclic pressure loading dependent fail-ure of pipeline dents. All three assessment levels draw upon information regarding pipeline operational, material and mechanical damage data. The assessment level selection and accuracy of the results are based upon the complexity of the features, the availability of required data and the level of detail and certainty in the input data. The three levels provide a range of alternatives for integrity management, where the appropriate method to use is dependent on the desired outcome and the available information.
PR-000-18COMP-R03 Damage Prevention Compendium
Authors: Marlow Thomas
Published: August 2023

The PRCI Technical Committees have carried many research projects related to the subject of Damage Prevention. This report; therefore, presents a summary of past PRCI-funded studies in the area of Damage Prevention. Since studies sponsored by other industry groups (e.g., INGAA, EPRG, APIA, CEPA, etc.) or by individual pipeline companies are not included, this report does not represent a review of the topic in the broader industry-wide sense. Instead, it is designed to provide a guide to past work so that current TC members can identify and locate project reports that might be of use in addressing their current day-to-day damage prevention issues.
PR-471-16206-R02 Suction Piping Effect on Pump Performance CFD
Authors: Chatagny Laurent
Published: August 2023

CFD simulations of pump suction piping coupled to a double suction volute pump were performed with oil at a viscosity of ~90 cSt. Two variants of the suction piping were modeled in order to investigate their effect on the pump performance. Measurement data obtained during PRCI project CPR-15A were used to validate the CFD setup. The CFD results were mostly in line with the measurements, in particular performance and pressure tap values in the suction piping. The pump rotor forces predicted by CFD however showed significant differences to the measured values. The CFD setup presented in this report provides a basis framework for further CFD investigations.

This work will benefit the liquids pipeline station designers and operators and also CFD analysts by providing CFD comparisons to benchmark measurements.
PR-214-153739-R01 ERW Fatigue Life Integrity Management Improvement-Phase III
Authors: Dinovitzer Aaron , Tiku Sanjay , Eshraghi Amin
Published: August 2023

While the general fracture mechanics methodology for calculating fatigue lives is well documented and validated, its application in the definition of pipeline system fatigue lives have differed from field experience. The source and magnitude of the conservatism inherent in the calculated fatigue life estimates are a concern when establishing integrity management programs. Of particular interest, are the fatigue life estimates used in the integrity management programs for Electric resistance welding (ERW) pipeline systems that are primarily concerned with pipe wall anomalies oriented along the pipe axis.

In this project, fatigue crack growth rate parameters were generated for pipe body and ERW. Axial flaws of different sizes were machined in pipe body and weld center line of two different pipe geometries and subjected to cyclic pressure tests. Fatigue crack growth rate of the flaws in the full-scale fatigue tests was monitored. The full-scale fatigue tests results were compared to existing codified treatments to quantify the level of conservatism inherent in the current state of practice. Recommendations were provided to enhance the precision and manage conservatism in fatigue crack growth rate calculations used in integrity management.

This report has a related webinar.
PR-214-174517-Z01 Development of Sleeve End Fillet Weld Stress Intensity Factor Calculator
Authors: Dinovitzer Aaron
Published: August 2023

The objective of the project documented in the following report was to simplify the use and further demonstrate the application of the complex formulation developed for the stress intensity solutions developed in the previous project. The primary output of the project is a set of software tools (i.e. a Microsoft Excel based tool and a standalone executable software tool) that allows for the rapid calculation of the stress intensity factor solutions along with a set of sample calculations illustrating the use of the software tools. Additionally, a set of sensitivity analyses have been performed that illustrate the effect of various parameters on the SIFs.
PR-214-134502-R01 Weld Hydrogen Cracking Risk Management Guide
Authors: Dinovitzer Aaron
Published: August 2023

PRCI and other organizations have funded research and development programs related to weld hydrogen cracking to develop tests, define hardness limits, understand diffusible hydrogen delivery, evaluate hydrogen cracking delay time and define weldment material hydrogen cracking susceptibility. These projects have produced results that can be used in developing or approving welding procedures, and electrodes or consumables. With all of this information available, hydrogen cracking is still being observed in new construction and in-service welds. This report has assembled samples of this information to provide an outline of current practice and knowledge. From this overview, gaps in knowledge or tools have been identified to support defining the path forward and enhance our understanding of how to predict the occurrence and preclude hydrogen cracking from weldments. Some concepts, identified in this document, are demonstrated to illustrate what can be achieved in support of weld hydrogen cracking management.