bluuebunny/crossref_metadata_2025 huggingface dataset:
L51666 Surface Preparation and Coatings on the Susceptibility of Line Pipe to Stress-Corrosion Cracking
Authors: Bruce  , Li
Published: August 2023

Within the last decade, a number of gas pipeline companies throughout the world have identified the presence of Stress-Corrosion Cracking (SCC) on their pipelines. While the cause of the SCC resulted from a multitude of factors, there appeared to be a commonality relating to pipeline coatings. Although SCC has occurred under polyethylene/PVC tapes and enamel coatings, not a single incident has been recorded where SCC has occurred on a fusion-bonded-epoxy coated line. The three major factors that were thought to account for the difference in the SCC performance of the various coatings were; (1) resistance of a coating to disbonding, (2) the ability to pass current through the coating and thereby protect the disbonded regions and (3) the surface preparation of the line pipe prior to coating application. These factors were addressed in this three-year program for PRCI.

This report examines the relationship between coatings and surface preparation and the likelihood of subsequent stress corrosion cracking. Standard Cathodic disbondment tests, measurements of potential gradients beneath disbonded coating, electrochemical measurements of current passages through coatings and actual SCC tests are described and results reported.
L52294 Corrosion Assessment Guidance for High Strength Steels
Authors: Chauhan Vinod
Published: August 2023

For the burst tests on high strength line pipe investigated in this report, standard assessment methods used by the pipeline industry generally give conservative failure predictions. For a small number of test points the ASME B31G, Modified ASME B31G and the LPC-1 methods gave non-conservative failure predictions when used to assess defect depths greater than 50% of the pipe wall. However, for machined defects, particularly those that are rectangular flat bottomed patches the use of ASME B31G and Modified ASME B31G to predict failure pressures may be inappropriate because the area of metal loss can be underestimated. Therefore the results need to be treatedwith caution. The RSTRENG method is the most reliable and conservative method forpredicting the failure pressure of corroded pipelines. RSTRENG predicts conservative failure pressures for defect depths up to 80% of the pipe wall in line pipe of strength grades up to X100. Modifying the flow stress to equal the arithmetic mean of the specified minimum yield strength and the ultimate tensile strength adds conservatism tothe calculated failure predictions. The non-linear FE method gives failure predictions within a scatter band of ~�10%, although in a number of cases the failure predictions are nonconservative. This level of scatter is typical. More accurate modeling of the geometry and material properties, to take into account of any through wall variation, should reduce the observed scatter.
L51752 Water Crossing Design and Installation Manual
Authors: Author Unknown
Published: August 2023

The pipeline industry has recognized the need for a reference guide to assist design personnel in the selection of the most environmentally appropriate and cost-effective construction techniques for pipeline water and wetland crossings. Operating companies have already been developing, implementing, and perfecting water and wetland crossing techniques and associated preventative, mitigative, and monitoring procedures in order to minimize the impacts on water quality and associated habitat. However, these activities, to date have largely been performed on an individual basis with little transfer of technology or information, which has led to duplication of effort inmany areas. This document outlines relevant background studies and investigations, crossing technique selection and design, methods of prevention and mitigation, inspection and monitoring, restoration and the present regulatory framework under which pipeline watercourse crossings are assessed and constructed. The specific study contents and design procedures are presented as a guide from which qualified personnel can develop specific programs and mitigative techniques.
L51776 Evaluation of Ultrasonic Technology for Volumetric Weld Inspection of Pipeline Girth Welds
Authors: Dijkstra
Published: August 2023

The work performed in this project can be regarded as a continuation of an earlier PRCI project: "Evaluation of Ultrasonic Inspection Techniques for the Root Region of Girth Welds" (project PR-220-9123), which was completed by the end of 1995. In that project, the performance of modern systems for mechanized ultrasonic inspection of girth welds in pipelines was evaluated with the emphasis on the weld root, which can be considered historically as the most difficult part of the weld when it comes to conventional ultrasonic inspection. In the current project, this was extended to the entire weld. Already in report PR-220-9123, it was stated that a structured evaluation would also help to arrive at a generic approval of mechanized UT systems for use in pipeline industry, to reduce or replace job-specific qualification tests. This point is still valid. The results of the first project, and hopefully also of this one, will be an important basis for international efforts currently being undertaken to develop such approvals, as well as to arrive at adapted acceptance criteria for weld defects. The current project was, similarly to the previous one, built around a number and a variety of representative test welds, using different welding techniques. These were inspected with Rotoscan, also using improvements (such as simultaneous TOFD), partly initiated on the basis of the work done in the previous project, and with radiography. They were then destructively tested for correlation with the NDE results.
L51710 Active Noise Silencing
Authors: Jay
Published: August 2023

Many natural gas compressor stations which were previously located away from residential areas are now being encroached upon by surrounding building developments. Furthermore, an increased awareness of community noise issues has proved to be the impetus for investigating and developing more effective noise control methods and treatments for natural gas compressor facilities. This project investigates the feasibility of applying Active Noise Cancellation (ANC) to the exhaust of a large, internal-combustion reciprocating type engine. Large reciprocating internal combustion engines pose significant challenges for the noise control engineer. In the case of the engines employed at Tennessee Gas Pipeline Company Compressor Station 229, these engines radiate extremely low frequency exhaust noise into the surrounding environs. These engines produce discrete frequencies in the exhaust spectra with a particularly strong component at 26.5 Hz, which corresponds to the fundamental firing frequency (the 5.0 rotational order) of the engine; significant attenuation of the raw exhaust noise can be particularly difficult due to the sound power and spectral content. Traditional methods would necessitate a very large silencer in order to realize improved attenuation of the exhaust noise, relative to the existing silencer.

Measurements were conducted at the error microphone location, at 1.0 meter from the exhaust outlet and at the property line. At a distance of 1.0 meter the WNCT integrated active / passive silencer yielded 84.5 dBA (92.3 dBL) while the original equipment silencer yielded 92.7 dBA (98.8 dBL). Band-limited (DC - 200 Hz) measurements were taken at the error microphone location; control off (WNCT passive - only): 109.8 dBL overall, 107.7 dBL 26.5 Hz component. With control on (WNCT active + passive) at the same position overall noise was 99.7 dBL with the 26.5 Hz component reading 89.1 dBL. Far-field A-weighted reductions were inconclusive due to the presence of other contributing noise sources possessing similar noise characteristics. Flow resistance measurements indicated that back pressure had been reduced by 95% relative to the original equipment silencer through the use of the integrated WNCT active / passive silencer.
L51713 Effective Procedure Variables for Weld onto In-Service Pipelines
Authors: Gibson  , Maxey
Published: August 2023

The ability of the flowing contents to remove heat from the pipe wall causes welds made onto in-service pipelines to cool at an accelerated rate and makes these welds particularly susceptible to hydrogen cracking. Several approaches exist for qualifying procedures where the thermal conditions produced by the flowing pipeline contents are simulated, allowing the ability of a procedure to produce sound, crack-free welds to be demonstrated.

This report documents the various methods that can be used, under a number of different conditions, for simulating the proper cooling effects that will be experienced when welding on in-service pipelines. Three candidate methods were selected and evaluated based on their simplicity and their ability to produce realistic weld cooling rates. Several field trials were undertaken in conjunction with actual in-service welding operations conducted by PRCI-member companies, and using a flow loop at the GRI Metering Research Facility, to collect weld cooling rate data to establish which procedure qualification conditions are applicable for various actual in-service conditions.Several field trials were undertaken and documented within this report on actual in-service welding operations as well as using a flow loop at the Gas Research Institute (GRI) Metering Research Facility to collect weld cooling rate data to establish which procedure qualification conditions are applicable for various in-service conditions and pipe repairs.
L51726 Guidelines for Riser Splash Zone Design and Repair
Authors: Young
Published: August 2023

This report provides guidelines for riser and splash zone design, provides a detailed overview of existing riser repair techniques and products, and provides guidelines identifying the capabilities and limitations of riser reinstatement systems. The objectives of this study were to establish the current state of technology for riser design and capabilities of riser repair systems; and to provide guidance for selection of a repair system with minimum down time and loss for production in the event of unanticipated damage.
L51880 Influence of Higher Design Factor on Structural Integrity of X70 and X80 Pipelines
Authors: Nessim
Published: August 2023

Most pipelines in Class 1 areas are currently designed to a utilization factor of 0.72 using steel grades of up to X70. Using higher strength steels and/or a higher design factor can reduce the wall thickness and construction cost of such pipelines. High strength steels tend to have high yield-to-tensile ratios and lower overall post-yield tangent stiffness. This raises concerns about the potential for excessive plastic deformations under high hydrostatic test pressures. Combined with a high design factor, high steel grades will also lead to thinner pipe walls and reduced tolerance to thickness-dependent failure mechanisms such as corrosion, cracks, and dent-gouges. This effort evaluates the ability of a newer pipelines to safely operate at higher yield stresses.
L51906 The Role of Redox and Corrosion Potentials in the Corrosion of Line Pipe Steel
Authors: King  , Jack
Published: August 2023

A combined lab and field program has been performed to study the external corrosion behaviour of buried linepipe. The overall aim of the project was to attempt to correlate pipe damage with measurable soil properties, in particular the redox potential as measured by buried soil probes. The lab component of the project involved the measurement of weight-loss corrosion rates in three types of soil, under saturated and as-received moisture conditions, and under permanently aerobic, permanently anaerobic or cyclic anaerobic/aerobic redox conditions. The soil conditions and coupon corrosion potentials were monitored during the course of the tests. In the field component of the study, pipe-depth soil properties were monitored using permanent NOVAProbes to measure the redox potential, soil resistivity, pH and temperature. Daily readings were taken at some locations with the aid of a custom-designed datalogger. Corrosion information was obtained from buried weight-loss or electrochemical coupons, from pipe excavations or from data from repeat in-line inspection runs.
L51821 Evaluation of Weldable 13 Percent Chromium Steels for Linepipe Applications
Authors: Woollin
Published: August 2023

The overall aim of the project was to demonstrate the ability to produce welds suitable for linepipe applications in nominally weldable 13%Cr stainless steels covering the range of grades being marketed as low cost alternatives to 22%Cr duplex stainless steel. This included the following: (i) Development of welding guidelines giving sound joints in weldable 13%Cr steels, with minimum preheat requirement. (ii) Quantification of the mechanical, corrosion and environmental cracking properties of weldments in weldable 13%Cr steels. (iii) Quantification of the effect of brief PWHT cycles on weldment properties in weldable 13%Cr steels.
L51960 Acoustical Pipe Lagging Systems Design and Performance
Authors: Stevens R. D. , Chapnik B. V. , Howe B.
Published: August 2023

Noise levels radiated from the exterior of a pipe wall can significantly contribute to the overall noise levels on the site of a gas plant and at neighboring properties. The noise inside the piping is generated both by the gas compressor itself, and by the flow of gas through valves, elbows and fittings. Sound inside the pipe couples to the pipe wall by exciting vibration modes, some of which are radiated from the exterior of the pipe into the air. Piping is geometrically circular, which provides it with considerable increased stiffness versus a flat plate, and thereby assists in its ability to contain low frequency sound inside the pipe. At high frequencies, where the wavelength of sound is short compared to the dimensions of the pipe, the response of the pipe approaches that of a flat plate, and considerably more sound is transmitted. Between the low and high frequency ranges lies the ring frequency, at which the wavelength of sound is equal to the circumference of the pipe; at this resonant frequency, a maximum amount of noise is transmitted out the pipe wall. For smaller pipe sizes, the ring frequency occurs above 5 kHz. For larger pipe sizes on the order of 24 inches to 36 inches, the ring frequency occurs in the range 1 kHz to 3 kHz. These frequencies fall in the most audible range of the sound spectrum. Low frequency sound is not usually of concern for pipe radiated noise, unless the source generates considerably low frequency energy. Acoustical lagging systems typically include one or more layers of porous insulation, to absorb sound and decouple vibration, and one or more layers of an impervious, heavy barrier material to contain the sound. The test configurations for this study were based on systems reported as commonly being used by PRCI member companies. Most of the member companies use fixed-in-place lagging configurations in which the various materials are applied in discrete layers to the pipe during installation. Self-contained, removable blanket systems are also in use by some member companies instead of fixed-in-place configurations, or around equipment such as valves where periodic removal of the lagging is necessary. This study provides a review of acoustic lagging systems for above ground gas piping to minimize noise.
L52048 Evaluation of the Interaction of Mechanical Damage on Welds
Authors: Dinovitzer
Published: August 2023

Failures in transmission pipelines are often the result of mechanical damage. The US DOT has indicated that 20 to 40 percent of the serious pipeline incidents in any given year are related to mechanical damage. This damage is due to third party activities, mishandling during construction, pipeline bedding material consolidation, or ground movement.

This project report includes a discussion of the following work: Development of a criteria for weld interaction with restrained rock dents, pipe ovality and wrinkles; Development of a means of considering pressure fluctuation severity in these criteria, and Development of guidance and recommendations on how to consider the effects of soil confinement.
L22279 Further Studies of Two Methods for Repairing Defects in Line Pipe
Authors: Kiefner
Published: August 2023

An essential requirement of most pipeline systems is that they remain in-service even when repairs must be carried out or when branch lines must be added, This need has led to the development of widely accepted practices of making in-service repairs and hot-taps. While both of these practices necessarily entail some risks (i.e., because of the pressures or contents of the systems) experience has shown that they can be carried out safely and effectively. In the case of repairs to defective areas, however, the approach has historically been one of well-justified overconservatism, that is, repairs have usually been made only to relatively innocuous defects that might not have caused a problem even if left alone. In many cases costly shut-downs and pipe replacements were effected when an in-service repair would have sufficed simply because the effectiveness of the known repair methods had never been evaluated.

This report describes a program undertaken to evaluate the degree of effectiveness of full-encirclement split sleeves and deposited weld metal with respect to repairing a variety of potentially serious defects. The evaluations were made on full-scale line pipe samples containing different kinds of actual and artificial (machine-cut) defects. The ultimate goal was to arrive at criteria for making safe permanent repairs through an understanding of how and why these repairs strengthened defective areas. The study revealed that when properly used, either type of repair can greatly improve the strength of defective areas of pipe.
L51515 Monitoring and Intervention on Pipelines in Mining Subsidence Areas
Authors: Kiefner
Published: August 2023

Longwall mining can constitute a threat to the integrity of a pipeline by way of surface subsidence and soil strains. The subsidence and soil strain phenomena associated with longwall mining have been studied in detail both in the United Kingdom and the United States. Empirically-based methods are available to predict both subsidence and surface soil strains. These methods can be used to estimate the possible effects of subsidence on buried pipelines.

The objectives of this study were to review the effects of longwall mining subsidence on pipelines and to develop concepts for preserving the integrity of pipelines affected by such subsidence. Presented in this report is a discussion of the subsidence phenomena and terminology, calculations for hypothetical settlement cases, the appropriate monitoring and intervention responses with respect to any possible effects on a pipeline, and examples of actual pipeline monitoring experience. A suitable strain monitoring technique is described in this report.
L51775 Susceptibility of Modern ERW Pipe to Selective Weld Seam Corrosion in Wet Environments
Authors: Lukezich
Published: August 2023

Grooving corrosion is a phenomenon by which the weld seam of electric resistance welded (ERW) pipe is preferentially attacked in wet natural gas environments containing CO,. The attack initiates as an aligned string of pits which grow and intersect, forming a round-bottomed groove of damage centered on the weld seam. The susceptibility of ERW pipe to this damage mechanism is known to be related to the chemical composition (particularly the sulfur content) of the pipe, the welding process employed, and the use of a post weld heat treatment. Of particular concern to the natural gas pipeline industry is the fact that at the resent time there are no effective means for predicting the susceptibility of a specific lot of ERW pipe to grooving corrosion, prior to placing the pipeline in service.

The objective of this program, therefore, is to begin the development of an accelerated laboratory test technique which may be useful as a screening test to establish the susceptibility of an ERW weld to grooving corrosion. A stepped potential, potentiostatic electrochemical test method was used to evaluate the susceptibility of ERW welds from five different pipe samples to grooving corrosion in environments representative of natural gas production. Three of the welds were believed to be susceptible to grooving corrosion and the remaining two were believed to be non-susceptible. Testing was performed under a variety of conditions (environment chemistry, temperature, and levels of polarization) in an attempt to identify conditions which enabled the correct differentiation between the susceptible and non-susceptible specimens.
L51793 The Effects of Water Chemistry on Internal Corrosion of Steel Pipelines
Authors: Sridhar  , Dunn
Published: August 2023

The ability to safely transport wet, untreated natural gases through pipelines offshore or at other inaccessible locations is an important factor in the development of new gas fields. The internal corrosion rate of steel pipelines varies in a complex way with the gas composition, specifically CO2 , O2 , and H2 S, and condensed water chemistry. Estimating the corrosion rate of steel at inaccessible locations from the analysis of the gas and water composition from an accessible location will enable a better determination of the need for corrosion inhibitors. Quantitative understanding of the corrosion rate of steel under these conditions will be key to an accurate risk assessment of pipelines from internal corrosion.

Previous work examined the effects of gas composition and slow liquid flow conditions on corrosion of steel. A parametric equation was developed that essentially reflected the deleterious effects of CO2 and O2 , and the beneficial effect of H2S on corrosion (Lyle, 1997). While this study provided important information regarding the deleterious effect of oxygen in the gas phase, the effects of condensed water composition, especially scale-forming species such as calcium and magnesium, were not examined. Furthermore, a better thermodynamic and kinetic understanding of the effects of the gas and liquid phase composition was needed. The present project, while an extension of the previous project, breaks important new ground: (i) the water chemistry typically found in pipelines is included in the tests; (ii) the scale and corrosion product formation is examined using a thermodynamic speciation software; (iii) surface analysis of the corroded samples is performed using laser Raman spectroscopy in order to confirm the thermodynamic model prediction; and (iv) electrochemical tests are conducted to understand the corrosion kinetics. A discussion of the general literature on internal corrosion is presented in the next section, followed by a summary of results from previous SwRI projects in this area. The thermodynamic approach and results are presented in Chapter 2. The experimental results are presented in Chapters 3 and 4, respectively, along with a discussion of the results in terms of thermodynamic and kinetic framework. Chapter 5 summarizes the results of this project and provides recommendations for further investigations. Details of the thermodynamic calculations, electrochemical experimental results, and analyses of the corrosion products are presented in the appendices.
L51796 Document CEM Experience in Natural Gas Transmission Industry
Authors: Crocker  , Raju  , Yang
Published: August 2023

Since passage of the 1990 Clean Air Act Amendments (CAAA), continuous emission monitoring system (CEMS) vendors, manufacturers, research organizations, parametric emissions monitoring system (PEMS) vendors, consultants, and source owner/operators have been developing strategies to satisfy compliance monitoring requirements that may eventually apply to many gas turbines and engines. A variety of CEMS and PEMS approaches have been developed, and evaluated to determine overall performance and cost. In addition, a few natural gas transmission companies have been required to install and operate CEMS on specific engines and turbines in order to comply with existing State permitting requirements or emissions trading programs.Within the next five years, the Environmental Protection Agency (EPA) is expected to promulgate a series of stationary source, air emission regulations that will have a significant impact on many industrial sources. In addition, EPA will be issuing regulatory revisions, policy manuals and guidance documents to further clarify the implementation and enforcement of rules recently promulgated - e.g., Title V Permitting, Compliance Assurance Monitoring (CAM) and Credible Evidence rules. As a part of each of these anticipated rules, revisions, and supporting documents, EPA will require and continue to refine corresponding compliance monitoring procedures and performance specifications. For the natural gas transmission industry, the anticipated regulatory changes could result in substantial increases in the cost of environmental compliance. Costs associated with pollution control (including reductions in engine/turbine efficiency), compliance monitoring, emissions reporting and recordkeeping may all increase as a result of pending regulatory requirements.

This report has been prepared to document the natural gas transmission industry's experience operating continuous emission monitoring systems (CEMS) on reciprocating engines and stationary gas turbines and to discuss some of the more critical, technical issues that will have to be addressed if pending regulatory changes require the use of CEMS. In particular, this report provides technical discussions regarding the performance, operation, maintenance and costs of a CEMS program for compliance monitoring of nitrogen oxides emissions.
L52344 Background of Linepipe Specifications
Authors: Wang
Published: August 2023

Some of the future pipelines are expected to be constructed in remote areas. The environment in these areas can impose higher longitudinal plastic deformation on the pipelines. Such environmental conditions include, but not limited to, frost heave and thaw settlement in the northern arctic region, seismic activity, slope instability, mine subsidence, upheaval buckling, etc. The overall industry experience for this type of loading is very limited.

The other trend in new pipeline construction is the move towards higher internal pressure (design factor of 0.80 as opposed to the more traditional 0.72 for Class 1 designs) and the use of high strength linepipes (API 5L Grade X70 and higher). The ability to operate at high international pressure enhances the economic return of the pipelines and provides additional incentive to select high strength line pipe.

The focus of this report is the mechanical properties of the linepipes and their influence on pipeline performance. The alloy design of steels, plate and coil rolling practice, and pipe manufacturing process can have profound effects on the resulting mechanical properties of the linepipes. The specifications of these manufacturing parameters leading to the final mechanical properties are out of the scope of this report.
L52339 Small Scale Low Constraint Fracture Toughness Test Results for High Strength Pipelines
Authors: Park
Published: August 2023

This is the fifth report of a series of seven reports detailing the small-scale mechanical testing performed on the trial welds in this consolidated program. An outline of the reporting flow is given in the Introduction to the Summary of Mechanical Properties report 277-T-08. The present report contains the results of application of the low-constraint tensile toughness test, supplemented with results of shallow-notch bend tests, to the three series of welds in the consolidated program, including tests on base metal, weld metal, and HAZ.
L00210 Noise Abatement Volume 1 - Physiological Psychological and Legal Aspects of Noise
Authors: Sharp James , Damewood Glenn , Sparks Cecil , Hanchett Miles
Published: August 2023

In an effort to better understand the detrimental effects of noise on worker productivity and general well-being, this report presents data gathered in the following three areas: (1) physiological and psychological effects of sound on man; (2) a nationwide survey of legislation concerning compensation for loss of hearing; and (3) a survey of anti-noise legislation in use in communities in the United States.
L51443 Evaluation of Flaw-Depth Measurement Accuracy Using Ultrasonic Inspection Techniques
Authors: Gruber George J.
Published: August 2023

The objectives of this project were to: 1) Establish the accuracies of four ultrasonic flaw-sizing techniques; and 2) Provide a direction for future work in the transfer of flaw-characterization technique(s) from the laboratory to field use. The four ultrasonic techniques for sizing flaws in pipeline girth welds were evaluated against a set of seventeen girth-weld flaws that included cracks, incomplete fusions, inadequate penetrations, slag inclusions, a gas pocket and a porosity. The correlations were poor for the results obtained by two versions of the decibel-drop technique. The best results were obtained from the supplemented satellite-pulse observation technique.
L00070 Flow of Natural Gas through High-Pressure Transmission Lines
Authors: Johnson
Published: August 2023

This document examines the data and formulas used to calculate the flow of natural gas through pipelines. Because of the lack of sufficient data, flow tests were made on 29 pipelines, covering a total of 757 miles. Comparisons were made between the coefficients of friction and the internal diameter of the pipe as expressed by the pipeline flow formulas and as determined from the tests used in this investigation. A special series of tests on small experimental pipeline were made to determine the relative delivery capacities of a pipeline when gas was flowing in the direction of increasing and decreasing diameters. In addition, a study was conducted of the physical and chemical properties of natural gas that influence flow.
L51529 Deposition Transport Models for Compressor Station Emissions
Authors: Reid  , Rooney
Published: August 2023

Report investigating applicability of existing models of the formation, transport, and deposition of acid species to natural gas pipeline compressor stations. Provides recommended statistical, Lagrangian and Eulerian models for mesoscale and long-range and suggested enhancements as necessary.
L51527c State-of-the-Art Report on Multiphase Methods Vol 3
Authors: Rothe
Published: August 2023

Three volumes. Report based on a multi-year effort to develop a Two-Phase Flow Design Manual. Intended to assess the current application of multiphase flow hydraulic methods to system design. Volumes are as follows: Vol. 1, Guide to Quick Calculations; Vol. 2, Guide to Computerized Calculations; and Vol. 3, Theoretical Supplement.
L51538b Guidelines for Subsea PL Repair and Tie-In Systems Vol 2
Authors: Unknown Author
Published: August 2023

Gives a detailed overview of existing and development maintenance and repair systems. Guidelines identify economies, capabilities and limits of repair systems for a wide-range of water depths, pipeline diameters, and sea (local) conditions; damage assessment included.
L51520 Parametric NOx Control Method Tests for In-Use Engines
Authors: Dietzmann
Published: August 2023

Technical report presenting results of an experimental program to reduce NOx emissions through changes in operating controls. Concludes that meaningful reductions can only be achieved at unacceptable engine operating conditions.
L51611 State-of-the-Art Methods for Multiphase Flow Pipelines
Authors: Kiefner  , Alexander
Published: August 2023

This report concisely documents the state-of-the-art in two-phase flow methods to the design of pipelines for the gas and oil industry. The report is written in a manner suitable for use by analysts who want to develop computerized methods to perform the multiphase calculations. The approach used in the methods described here provides a general structure for the multiphase flow methods to be used in pipeline design. The underlying theories for the determination of the flow regime and the calculation of pressure drop and holdup are mechanistic. The fundamentals of the underlying theory permit scaling of the predictions to pipe sizes or gas densities (pressure) where data are lacking.
L51615 Ultrasonic Inspection of the Root Region of Girth Welds
Authors: Groeneveld  , Elsea
Published: August 2023

Describes a test program involving two ultrasonic inspection techniques to permit characterization of pipeline girth weld defects which could discriminate benign weld profile features. The dual-probe method and the time-of-flight diffraction method are described and tested in computer simulation extending the technique to detect planar defects in the root region of pipeline welds.
L51553 Assessment of Mechanistic Methods for Multiphase Lines
Authors: Crowley
Published: August 2023

Report in the format of a technical note describing mechanistic analysis methods developed in the course of a series of research projects involving pressure drop and liquid hold-up prediction in multiphase flow. The calculated results are compared with data from the A.G.A. Gas-Liquid Pipeline Data Bank (L51521).
L51687 Subsea Repair of Gas Pipelines without Water Flooding
Authors: Abraham
Published: August 2023

This study documents the state-of-the-art equipment and procedures available for use in isolating mid-line subsea pipeline repairs to prevent back-flooding. The study notes the lack of effective non-intrusive methods and the potential for cost savings when suitable methods are developed.
PR-348-09602-R01 Determine New Design and Construction Techniques for Transportation of Ethanol
Authors: Chambers
Published: August 2023

This report summarizes results of the research study titled, �Determine New Design and Construction Techniques for Transportation of Ethanol and Ethanol/Gasoline Blends in New Pipelines� (WP #394 / DTPH56-09-T-000003). It was prepared for the United States Department of Transportation, Pipeline and Hazardous Materials Safety Administration, Office of Pipeline Safety. The technical tasks in this study included activities to characterize the impact of selected metallurgical processing and fabrication variables on ethanol stress corrosion cracking (ethanol SCC) of new pipeline steels, develop a better understanding of conditions that cause susceptibility to ethanol SCC in fuel grade ethanol (FGE) to support better monitoring and control, and develop data / insights to provide industry-recognized standards and guidelines to reduce the occurrence of ethanol SCC. This research was approached through a collaboration of Honeywell Process Solutions (Honeywell), the Edison Welding Institute (EWI), and Electricore Inc. (prime contractor) with oversight and co-funding by the Pipeline Research Council International (PRCI) and Colonial Pipeline.

The program's tasks were as follows:

Evaluation of Steel Microstructure Effect on Ethanol SCC Resistance
Effects of Welding and Residual Stress
Evaluation of Surface Treatment Effects
Evaluate Effects of Pipe Manufacturing Process
Specification of Polymeric Materials for New Construction
Control and Monitoring of Oxygen Uptake
Internal Corrosion Monitoring
Standardization of SCC Test Methods
Roadmap for Industry Guidelines for Safe and Reliable Pipeline Handling of FGE
PR-179-12603-R03 Energy Meter Performance Assessment Phase 1 Amendment - Blinded
Authors: Olsen  , Wise
Published: August 2023

Many pipelines utilize system chromatographs at delivery locations. The energy content of the gas delivered can have a significant time skew from the chromatograph. Therefore, the energy content of the gas at a delivery point may differ significantly from its associated system chromatograph. On lean burn engines with tight emission controls, changes in the energy content of the fuel gas can significantly alter the amount of air required to maintain emissions compliance. A reliable, low cost, and fast responding energy meter is desired for both scenarios described. Four Energy Meters are evaluated with six different gas compositions representative of gas compositions encountered on natural gas pipelines. The Energy Meter data is compared to a Micro GC to assess accuracy. After evaluation of the Energy Meters the same six gas compositions were operated in a CFR engine to measure methane number. The measured methane numbers are compared with methane numbers computed from energy meter data.
L00377 Noise Control Handbook Volumes 1 and 2
Authors: Pish
Published: August 2023

The initial objective of this program was to define noise effects and criteria both for employee hearing protection and prevention of community noise intrusion, and thereafter turned to the development of analytical and engineering techniques to identify, diagnose, and control noise problems at gas pipeline installations.

A first and vitally important step in any effective noise program is the development of a systematic approach to defining existing noise conditions and evolving a comprehensive control approach. Effective noise control programs can be developed which both evaluate compliance and identify the nature and intensity of significant sources without overreaction or over-expenditure. This report shows the major steps needed in any noise abatement program.
PR-015-14214-R01 Liquid Leak Detection Technology Review for Aboveground Facilities
Authors: Siebenaler  , Cortes
Published: August 2023

Liquid pipeline companies operate a number of different facilities, such as pump stations, that are part of the transport stream of hazardous liquids. Many of these facilities are typically unmanned and have a number of sources (e.g., flanges, valves, tanks, etc.) that can leak. The consequences of such a leak are heightened as the amount of time passes until the leak is detected. There is a need for a technology (or group of technologies) to be deployed at such sites to autonomously detect and raise an alarm in the event of a leak. A project was conducted to identify and evaluate (on paper) potential solutions for deployable technologies. The work on this project focused on leaks that originate at aboveground facilities in which the product either pools on the ground (e.g., crude oil, jet fuel, etc.) or changes phase above the ground upon exposure to atmospheric pressure (e.g., propane, liquefied natural gas, etc.). This work differs from prior PRCI research on continuous monitoring for buried assets in that continuous, subsurface detection is not required.
L51492 Evaluation of the Kaiser Effect in Pipe Steels
Authors: Godinez
Published: August 2023

Acoustic emission (AE) proof testing is a particularly attractive method of nondestructively examining large structures such as pressure vessels and pipelines because a total volumetric examination can be made with AE sensors mounted at relatively large intervals over the surface of-the structures. The proof test, to be effective, requires an increase in pressure that is significantly greater than previously applied pressure in order to elicit AE from existing defects. In the case of gas pipelines, however, overpressure of gas in the line represents a considerable risk. It is therefore desirable to develop a means of using AE to examine gas pipelines without excessive overpressure in the line. Even in a flawed structure, AE is significantly reduced or absent during reload to a previously attained stress. This is known as the Kaiser effect. The Kaiser effect is defined in ASTM E610 as \the absence of detectable acoustic emission until previously applied stress levels are exceeded.\" This quieting of AE during reload is believed to be connected with the reduction of compression yield which accompanies the increase in tensile yield as a result of the Bauschinger effect. This project was undertaken to evaluate the Kaiser effect recovery at several pressurization levels in pipeline steels to minimize over-pressurization during AE proof testing of pipelines.

The experiment to measure the Kaiser recovery was designed so that it would include the major types of defect scenarios and would cover the range of stress levels which a pipeline can experience. The defects, which were included in the tests, included the commonly occurring defects such as fatigue cracks, stress corrosion cracks, and corrosion pits. A specimen without flaws was also included. The effect of stress on the Kaiser recovery was studied by loading the specimens to four levels of stress: 25, 50, 75, and 90 percent of the yield strength of the material. The recovery of the Kaiser effect was measured by loading the sample to the same stress levels at certain intervals of time ranging from 10 minutes to 30 days. These tests were done to measure the acoustic emissions due to loading with an increase in the time during which the Kaiser effect could possibly recover.
L51389 The Removal of Detrimental Magnetic Fields at Pipeline Tie-Ins
Authors: Proctor Noel B.
Published: August 2023

Pipelines frequently develop an induced magnetic field caused by any one of the following: pipeline inspection methods; induced electrical currents in the pipe; adjacent pipelines; terrestrial currents; and/or the interaction with geomagnetic fields. The induced magnetic field can become intense enough to interfere with pipeline repair procedures that involve arc welding. This report provides some background on the origins of magnetic fields in pipelines, and presents a technique for demagnetizing the area immediately surrounding any surfaces to be welded. A step-by-step procedure is given for reducing the residual magnetic field to a practical level low enough for welding purposes.
L51445 Investigative Procedures for Examination of Failures in the Field
Authors: Kiefner  , Eiber
Published: August 2023

The ability to conduct a failure investigation depends on the quantity and quality of the evidence collected in the field. If, for example, the samples or evidence containing the origin or origins is not located in the field and taken into the laboratory, it is not possible to determine the probable cause. The need exists for a standardized recommended practice for pipeline failure data gathering.

The purpose of this report is to describe the procedures used in conducting the field examination portion of a failure investigation, to provide a basis for the selection of samples, and outline information that may be helpful in determining the cause of a failure. When confronted with a number of feet of broken twisted pipe strewn along a pipeline right-of-way, it can seem like an impossibility to reconstruct what caused a failure. Yet in several hundred investigations that have been conducted by the authors, the causes have been established. The field portion of the investigation has been divided into four steps: (1) Survey the failure site and fracture to define the nature of the fracture, (2) Locate the fracture origin or origins, (3) Estimate the probable cause, and (4) Select appropriate samples for detailed laboratory examination.

The procedure described herein is suggested for guidance in conducting the field-examination phase of failure investigations. It may not be necessary for all failures and, in some cases, additional information and steps may have to be implemented depending upon the specific suspected cause. The authors believe the procedure presented will be useful and serve as a building block.
L51637 Development of an Ultrasonic Stress Corrosion Cracking Detection Vehicle
Authors: Barton  , Card  , Pope
Published: August 2023

Stress corrosion cracking poses a serious threat to aging underground cathodically protected gas pipelines. As coatings deteriorate, conditions conducive to both corrosion and stress corrosion cracking become more common. There have been many ruptures in various pipelines throughout the world attributed to SCC. One of the most important steps in combating failure by stress corrosion cracking is regular, reliable and cost effective monitoring of the pipelines. Current methods available (including hydrotesting and MT) are either expensive, time consuming, or not entirely reliable. Regular testing of pipes would also improve understanding of stress corrosion cracking initiation and propagation.

Field trials of a prototype remote control stress corrosion cracking (SCC) detection vehicle� took place from the May 21st 1990 to the June 1st 1990, at Peterborough in South Australia, as part of an agreement with the Pipeline Research Committee, of the Pipeline Research Council International, Inc. The present vehicle is self-contained, battery powered and is controlled by an on board computer. The vehicle can operate in an evacuated line and maintains a telemetry radio link with a monitoring computer at the pipe entry position. The detection system consists of two piezoelectric ultrasonic wheel probes fired by dedicated electronics. The vehicle is programmed to move through a certain section of pipe to record areas of ultrasonic activity corresponding to SCC in the bottom section of the pipe.
L51485 Field Welding Procedures for Welding RE Treated Linepipe with the GMAW-S Process
Authors: Crowley
Published: August 2023

Describes the results of short circuit GMAW process development using a new gas mixture with CRC type welding equipment and assesses the hydrogen levels produced by the new gas mixture. A wide range of welding procedural conditions were used to examine all expected operating parameters. The results of both the field welding trials and the procedural experiments showed that the shielding gas mixture has to be modified to lower hydrogen levels to avoid porosity formation. However, the hydrogen analyses showed conclusively that even a 1% hydrogen shielding gas produces results equivalent to a low-hydrogen SMAW process.
L51731 Analysis of DOT Reportable Incidents on Gas Transmission and Gathering June 1984 through 1992
Authors: Eiber  , Miele  , Wilson
Published: August 2023

There is always a safety concern when there is release of liquified natural gas or gas from an LNG facility. There are certain parameters of an LNG leak which require the incident to be reported to the U.S. Department of Transportation (DOT)/Office of Pipeline Safety (OPS).

The objective of this study was to analyze the reportable incident data on gas transmission and gathering lines onshore and offshore to:(1) assess the safety record of the gas-transmission industry and (2) identify areas where corrective actions are appropriate. The particular focus was on areas or items that continue to cause service incidents so that the industry can focus its research in these areas. The 30-day incident report data presented herein were obtained from the U.S. Department of Transportation (DOT)/Office of Pipeline Safety (OPS). These data are for the time period from June 1984 through 1992. As of February 9, 1970, all gas-transmission companies were required to notify the OPS of a reportable incident. Each company experiencing a reportable incident is required to submit a report on Form RSPA F7100.2* within 30 days