bluuebunny/crossref_metadata_2025 huggingface dataset:
L51866 Field Studies to Support SCC Life Prediction Model
Authors: Leis
Published: August 2023

One objective of this project was to gather and analyze SCC field data on lines being retested for use in assessing the validity of current or future SCC models. The scope of this initial study was limited to colonies of SCC in one valve section of a pipeline that runs from Texas to the northeast of the United States. This valve section had an early history of high pH SCC. The susceptibility since has been controlled through hydrotesting and modifications to the gas compression to meet upstream demand while reducing the discharge temperature. In addition to collecting data to validate models of SCC, data were also developed to evaluate the suitability of a hand-held tool to measure the depth of SCC, because such results can be critical in the use of models in making serviceability and maintenance decisions.
L51654 Spatial Densities of Stress-Corrosion Cracks in Line-Pipe Steels
Authors: Parkins  , Leis
Published: August 2023

There was a need to define the spatial density of stress-corrosion crack arrays that develop in operating gas-transmission pipelines and in laboratory test specimens of line-pipe steel, to improve understanding of the factors that control the density and provide data to test models of pipeline cracking. Within the broad definition of crack density are included the locations, numbers, lengths, depths, and degree of linkage of cracks.

An analysis has been conducted of location, numbers, lengths, depths, and degree of linkage of stress-corrosion crack colonies in samples from the field and from laboratory tests. This has provided data to test any model of the cracking of pipelines. Thus, it is shown that crack densities are of the order of 5 cracks/mm of distance normal to the crack length direction and that the depths and lengths of cracks are distributed according to log normal and Weibull functions. During the growth stage of cracks in a colony, their spatial distribution is not random, because of the interaction of their associated stress fields. That interaction also results in the coalescence of cracks, an extremely important part of the overall growth process, and that interaction is defined quantitatively to provide further information to which modeling must aspire.
L52209 Application of Repair Coatings to Wet Surfaces
Authors: Ruschau  , Tossey
Published: August 2023

The field application of pipeline repair and rehabilitation coatings can be greatly dependent upon the ambient conditions on the day of the scheduled repair. In some cases, such as the application of FBE at girth welds, temporary shelters can be built over the girth weld area to protect pipe from the elements. However, for the majority of pipeline applications, coatings must be applied to a pipe surface that is not optimized for coating application. Specifically, pipelines which are in service during the repair coating operation will be at the temperature of the product flowing through them regardless of the ambient temperature. This poses a very large problem when the temperature of the pipeline is below the dew point of the ambient air, because condensation will occur continuously on the pipe surface.

The objective of this work was to determine the performance implications of applying pipeline repair coatings to wet or damp surfaces. Six liquid repair coatings were applied to steel substrates with varying degrees of surface wetness. Three coatings were standard epoxies; three were specially formulated for wet surface tolerance. The coatings were tested for cathodic disbondment resistance, mechanical strength, and how each coating interacts with water during curing. FTIR and DSC analysis of each coating when mixed and cured in wet conditions (water added to the mix) showed no evidence of water interacting with the coating and changing the chemical structure or the chemical properties. Thus it was concluded that the wet surface tolerant coatings, while manufacturers may claim that they were formulated to absorb and accommodate water, in reality just have a better ability to displace water than standard repair coatings.
L51903 Damage to FBE and Liquid Epoxy Coating from Hydrogen Outgassing from Welds
Authors: Payer
Published: August 2023

Hydrogen in welds and its affect on performance from the perspective of cracking and embrittlement of steels has been widely studied, and welding procedures have been developed to minimize the deleterious effects of hydrogen. The practical problem is whether hydrogen outgassing from welds causes damage to FBE and liquid epoxy coatings on pipelines. FBE coatings on longitudinal welds made at pipe mills have developed defects because of hydrogen outgassing. Field welds are often coated shortly after welding, inspected and either buried or submerged, and there is a greater chance for more hydrogen in the field welds than mill welds. If coating damage occurred by outgassing, the damage could go undetected and affect the pipeline corrosion control.

The objectives were to examine hydrogen outgassing as a cause of damage to FBE and liquid epoxy coatings, to collect and contrast experience with hydrogen in longitudinal welds and circumferential welds, to quantify hydrogen pickup and release from steel pipe and welds. Methods and practices are identified to avoid damage to FBE and liquid epoxy pipeline coatings from hydrogen outgassing. The approach was to examine epoxy coatings applied over welds for damage from hydrogen outgassing and to conduct experiments to determine the amount and rate of hydrogen desorption (outgassing) from welds. The effects of hydrogen desorption on coatings was examined for commercial FBE and liquid epoxy coatings along with screening tests with liquid glycerol and clear epoxy. Hydrogen desorption was measured directly on welds, and a model was developed to describe the outgassing of diffusible hydrogen and the amount of diffusible hydrogen remaining in the weld.
L52274 Survey and Interpretive Review of Operator Practices for Damage Prevention
Authors: Kiefner
Published: August 2023

Pipeline incident data show that about 22 percent of the pipeline incidents reported to the DOT for the period from 1995 through 2003 was caused by excavation damage. Only incidents from all forms of corrosion account for a higher proportion of the incidents, and the corrosion proportion is around 24 percent.

This work presents the results of a survey and interpretive review of pipeline operator practices for the prevention of damage to pipelines from mechanical excavating equipment. A recent joint industry-DOT project has produced a compendium of practices and technologies for preventing damage to pipelines. The work described herein represents a follow-on effort to determine how effective these practices and technologies have been with respect to preventing damage. The project was aimed at determining which techniques are effective, which are not effective, and which would be worth further investigation.
L51886 Performance of Magnesium Anodes
Authors: Yunovich  , Thompson
Published: August 2023

Magnesium anodes are provided to the corrosion control industry by a number of domestic and international manufacturers and distributors. Due to the difficulty and time involved in performance testing, anode composition is commonly the only criterion used for quality control by the end users. However, experience has shown that compliance of the anode chemical composition with the ASTM B843 Standard Specification for Magnesium Alloy Anodes for Cathodic Protection can be misleading and does not always differentiate between the anodes of different quality. Thousands of magnesium anodes are produced annually and provided by a number of suppliers to the corrosion control industry. Though the composition of the anodes from the various sources is comparable, the performance of the magnesium anodes is often radically different. Many of these materials have been shown to meet the compositional and potential specifications, and yet have had measured efficiencies as low as 7%.

The objectives of this project were: (1) to develop quality and performance standards determined by laboratory tests and field exposures. The project included testing a variety of anodes submitted by the manufacturers/distributors and the end users, representing all spectrum of the ASTM G97 Standard Test Method-based efficiency values; the anodes were characterized with respect to the Anode source, manufacturing process, macrostructure, chemical composition, anode type (standard/H-1 family /AZ63 family versus high-potential), and microstructure. Other investigations comprised assessment of the ASTM G97 Standard Test Method parameters that were most likely to make the most significant impact on the resulting anode efficiency values, e.g., testing environment (standard testing solution and saturated backfill), and current density (the low 1/10th of the standard'), the ASTM G97 standard, and the high (10X standard) values). Testing in saturated backfill was used for a comparison between the laboratory- and the field-based efficiencies.
L52187 Decompression Response of High-Pressure Natural Gas Pipelines Under Rupture or Blowdown Conditions
Authors: Botros  , Geerligs  , Given
Published: August 2023

The Pipeline Research Council International, Inc. found that Scandpower has software that is capable of predicting the transient response of a pipeline segment transporting either conventional or enriched dense phase natural gas mixtures when subjected to a controlled blow down or an uncontrolled rupture event. Consequently PRCI expressed a desire to pursue an experimental work to provide the basis for evaluating the adequacy of the existing software and/or define further development if any. NOVA Research and Technology Corporation (NRTC) was awarded a contract to perform the experimental work and compare results with prediction by the OLGA 2000 software.

The existing NPS 2 stainless steel decompression tube test rig at TCPL Gas Dynamic Test Facility (GDTF) in Didsbury, Alberta, Canada, has been expanded specifically for this project. The initial length of 30 meters was extended to 172 meters in order to simulate a longer length to diameter (L/D) ratio. Two sets of tests were conducted: one to simulate pipeline rupture and another to simulate controlled blowdown. Rupture was simulated by a rupture disc located at one end of the tube, while blowdown was affected by a typical blowdown stack and a reduce-bore ball valve. The test scope included three gas mixtures (conventional, medium rich and rich) and three initial pressures: 10, 14 and 20 MPa.
L52298 Augmenting MFL Tools With Sensors that Assess Coating Condition
Authors: Nestleroth
Published: August 2023

External coatings are routinely used to protect transmission pipelines from corrosion; however, coatings may degrade or disbond over time enabling corrosion to occur. Transmission pipeline operators often use magnetic flux leakage (MFL) in-line inspection tools to detect metal loss corrosion defects. Rather than finding the cause of a problem, failure of the coating within a corrosive environment, MFL corrosion surveys only find the result of the problem, corrosion defects that may permanently alter the pressure carrying capacity of the pipeline. Stress corrosion cracking (SCC) can be detected using in-line inspection (ILI) technology, but the availability of tools is limited and the cost of inspection is high compared to MFL inspection. SCC almost always occurs at coating faults; direct coating assessment could indicate future problems that could degrade the serviceability of the pipeline.

In this project, a new sensor was developed to assess external coating that could work with currently available ILI tools for minimal additional cost to perform the inspection. The sensors, electromagnetic acoustic transducers (EMATs), generate ultrasonic waves that are guided by the pipe material around the circumference of the pipe. The coating material and adherence can influence the propagation of the ultrasonic waves; changes in ultrasonic signal features were attributed to coating faults. This development used modeling and experiments to establish a more optimal configuration for coating assessment. A multiple feature approach was used. A commonly used feature, signal amplitude, provided good sensitivity to coating condition but was influenced by inspection variables. One unique feature identified in this development is arrival time of the ultrasonic wave. For the wave type and frequency selected, the wave velocity was different for bare and coated pipe. Therefore, disbonded or missing coating can be detected by monitoring arrival time of the ultrasonic wave, a feature that is amplitude independent. Another feature for assessing coating, absorption of selective frequencies, was also demonstrated. Coating assessment capability was experimentally demonstrated using a prototype EMAT ILI tool. All three detection features were shown to perform well in an ILI environment as demonstrated at Battelle"s Pipeline Simulation Facility and BJ Inspection Services pull rigs. Improvement to the prototype occurred between each test; the most significant improvement was the design and construction of a novel set of thick-trace transmitting and receiving Printed Circuit Board (PCB) EMAT coils. Implementation variables such as moisture and soil loading were shown to have a minimal influence on results.
PR-004-12602-R02 Performance of H2S Sensors
Authors: Donatello
Published: August 2023

Three hydrogen sulfide (H2S) monitors calibrated to detect concentrations between the ranges of zero to fifty parts per million (ppm) were acquired by the PRCI project advisory team and sent to GTI for evaluation. The three tested monitors were from different manufacturers using different detection methods and technologies. Each of the three H2S monitors was evaluated using testing protocols to determine the accuracy, precision, and signal response of each monitor.
L51464 Kinetics of Stress-Corrosion Cracking in Pipe Steel at 175F
Authors: Marschall
Published: August 2023

The kinetics of stress-corrosion crack (SCC) growth in gas transmission pipelines is not well understood. Several factors in pipelines act to make the SCC situation less pessimistic than it might at first appear. First, SCC cannot occur in a pipeline as long as the protective coating remains intact. Second, even if breaks in the coating do develop with time, it is unlikely that the electrochemical potential existing in that region will be constantly in the critical range for cracking. Third, unlike the laboratory specimens cited earlier, the steel will not be subjected to a constant rate of strain. Rather, it will be subjected to an essentially constant stress (perhaps with small fluctuations of a low frequency) that does not exceed 72 percent of the specified minimum yield strength (SMYS). This will result in a very low rate of strain (due to creep and stress cycling) and a rate that will diminish with time. Fourth, the temperature of the pipeline will usually be lower than the value of 175 F that is frequently used in laboratory experiments; stress corrosion cracking rates diminish substantially as temperature is lowered. In addition, the critical potential range for cracking is narrower at lower temperature.

The study of the effect of crack depth on crack-growth rate employed a pre-cracked cantilever-bend specimen. The method of loading the specimen and monitoring the crack growth is illustrated schematically. The stress at the crack tip was calculated by assuming the beam depth to be equal to the amount of un-cracked material below the notch and ignoring any stress concentrating effect of crack. Addition of the direct-current electric-potential (d-c E.P.) wiring for measuring crack growth required no alteration of the electrochemical cell or the loading fixture. Direct-current leads (14 gauge copper wire) were attached to the specimen outside the cell and potential probe leads (24 gauge iron wire) were spot-welded across the notch mouth. Upon completion of each test in the crack-depth-effect series, the specimen faces were polished and etched metallographically to confirm that intergranular stress-corrosion cracking (IGSCC) had occurred. The specimen was then fractured at a low temperature to reveal the total amount of crack growth by IGSCC.
L51537 Power Line Fault Current Coupling to Nearby Natural Gas Pipelines
Authors: Maxey
Published: August 2023

Electric and natural gas utilities often find it advantageous to share rights-of-way. Available methods for evaluating electrical effects on gas pipelines have been difficult to use at best, and at worst, incorrect. A generalized approach that addresses inductive and conductive interferences has not been available. Initiated to fill that need, this work is part of a research effort cosponsored by EPRI and the Pipe Line Research Council International, Inc. (PRCI)

�A generalized approach to the analysis of the effects of transmission line faults on natural gas transmission pipelines has been developed and is presented in this report. A state of the art user-friendly computational tool has been developed and verified for the analysis of interference between electrical power lines and nearby buried or aboveground pipelines. This computer program, ECCAPP, is distinguished by its ability to model and analyze accurately complex, realistic interactions between pipelines and power lines, using easily obtained input data. The final report consists of three volumes. An independent fourth volume was also developed to simplify the installation of the ECCAPP software.Volume 1 contains the theory upon which the ECCAPP computer program is based. A parametric analysis and graphical charts have been formulated using ECCAPP to permit estimates to be made in the field or during preliminary analyses for situations that are not too complex. A discussion of various useful mitigation methods is included. The discussion is based on previous research work and on the results of the parametric analysis.Volume 2 is a detailed user's manual which describes not only how to use the program itself, but also which engineering data must be sought during an analysis and how to assimilate it into a computer model. A detailed sample problem is included. A detailed \Glossary of Terms\" used by ECCAPP as well as suitable input data forms to be filled by power line and pipeline engineers are provided in the appendices.Volume 3 discusses the modeling and performance of pipeline insulation or coating.
L51729 Gas Scrubber Performance Evaluation - Measurement Methods
Authors: Svedeman
Published: August 2023

Scrubbers and separators are used in natural gas pipelines to remove solid and liquid materials from the gas stream. Failure to remove the entrained materials from the gas can result in equipment damage, increased pressure drop due to liquid accumulation, flow measurement errors, and corrosion. The performance of separators is rarely tested after a separator is installed because there is a lack of test instrumentation and it is difficult to conduct tests at the high pressures. The only indicators of poor separator performance are recurring problems in downstream equipment or the detection of accumulated materials in downstream piping. Instrumentation is needed that can verify separator performance when the unit is installed and to periodically monitor separator performance.

The report documents results of instrument tests. The objectives of the instrument evaluations were to verify that the instruments could be used to measure particles penetrating a separator, to provide a comparative evaluation of the instruments, and to identify any measurement problems that could be encountered in field testing. One important result was that the separator minimum removable drop size increased as the operating pressure increased. This trend is not generally known, since there is a lack of test results for pressures above atmospheric pressure. The separator performance test results are documented in this report.

Two different particle measuring instruments were evaluated for documenting separator performance. The two instruments were the video imaging system with automatic image analysis and the laser-based phase Doppler particle measuring system. The instruments were evaluated in laboratory tests that were conducted on a commercially available vane-type separator. The objectives of the instrument evaluations were to verify that the instruments could be used to measure particles penetrating a separator, to provide a comparative evaluation of the two instruments, and to identify any measurement problems that could be encountered in field testing. The video imaging system has a number of attractive attributes, but it was not able to measure the small diameter drops at the separator exit. The primary limitation was that the optical system could not clearly image the small drops (in the range from 5 to 30 um). The phase Doppler particle measuring system was capable of measuring all of the parameters needed to document the separator performance. Based on the instrument evaluations, future efforts on developing measurement methods for documenting separator performance should focus on adapting the phase Doppler system to field testing.
L51753 Natural Draft Aerial Coolers
Authors: Jebrail F.F. , Kistler R.S.
Published: August 2023

In recent years, environmental regulations have tightened and community involvement in environmental issues has increased. The pipeline industry has responded by attempting to reduce the negative economic and environmental impact of conventional air-cooled heat exchangers, which are characterized by high noise levels, excessive energy consumption, and high maintenance costs. While industry has had limited success in reducing air cooler noise using silencers and timed variable-speed fans, these solutions are costly. The most effective noise reduction method is to reduce or eliminate noise at its source. The primary goals of this investigation were to address key technical issues and to document natural draft aerial cooler (NDAC) design knowledge. The following objectives were identified:

- Form a project team from PRCI-recommended aerial cooler manufacturers to design a quiet aerial cooler

- Conduct technical and economic analyses to determine the actual operating needs and constraints of NDACs

- Conduct market analyses to evaluate and identify the marketing issues associated with NDACs

- Document the results of the project in a final report

In recent years, the number of environmental permits mandating the use of natural draft aerial coolers to reduce noise has increased. Natural draft aerial cooler technology can potentially eliminate noise and improve operational energy efficiency. A broad group of applications could benefit from this technology, including natural gas, engine jacket water, auxiliary water, and engine lube oil cooling. With noise regulations and penalties becoming increasingly stringent, natural draft heat transfer technology is becoming more important. No organization has as yet fully investigated it. The technical and economic feasibility of NDACs were investigated for natural gas, engine jacket water, auxiliary water, and lube oil cooler applications.
L51797 Life Management of the RB211-24C Gas Turbine
Authors: Bernstein
Published: August 2023

Gas turbine engines are in common use in the Gas Pipeline industry to drive gas compressors in compression facilities. One of the major cost factors in the operation of these turbines is the repair or replacement of the hot section components. Technology that can extend the operational life of these components, or increase the ability to repair these components, is of immediate financial and operational benefit to members of PRCI. The RB211 gas turbine engine is commonly used in compression facilities. The life of the model 24C HP turbine blades is currently inadequate, leading to early replacement at a cost of approximately $300,000 per set. Actual life is not known by the users (or the OEM) and existing estimates are unreliable.

Since users do not have adequate means to predict the point at which the blades must be retired, this study of the RB211-24C HP blade life factors was initiated to provide users with guidance for blade maintenance. The objectives of the project were to define the life factors affecting the repair and replacement decisions for the RB211-24C HP turbine blades. This includes determining the operative degradation modes of these turbine blades; the expected life of these blades as a function of engine operation; the potential to repair these blades, and the potential to obtain additional life and durability of the blades by the use of more protective coatings.
L51847 Fatigue Strength of Seamless Line Pipe and Modern ERW Line Pipe
Authors: Andrews
Published: August 2023

To resolve the question as to whether or not ERW pipe might prove inferior to seamless pipe in terms of resistance to cyclic stresses, the PRCI member companies decided to fund the project described herein to assess the performance of ERW pipe versus seamless pipe. Presented herein are the results of a research project on the serviceability of seamless line pipe and modern high-frequency-welded ERW (electric-resistance-welded) line pipe. Full-scale samples of both kinds of pipe were subjected in a laboratory environment to pressure cycles simulating hundreds of years of service. Four samples of ERW pipe and one sample of seamless pipe were tested. Each sample consisted of a 20-foot length of the material fabricated with end caps. Coupons were cut from the remaining pieces to accommodate tensile and impact tests and base-metal metallography. The 20-foot specimens were subjected to pressure cycles ranging from a minimum of 100 psig to the pressure level corresponding to 46 percent of the measured ultimate tensile strength of the material.
L51902 Cathodic Disbondment of Pipeline Coatings under Realistic Field Conditions.pdf
Authors: Payer
Published: August 2023

The primary objective of this study was to determine the cathodic disbonding behavior of several pipeline coating materials under realistic conditions and to compare the results with laboratory tests that are commonly used to evaluate CD performance of coatings. Laboratory tests were run under more realistic conditions to simulate field conditions for three types of coatings. The move toward more realistic conditions was accomplished by:-substitution of soil extract solutions for the 3% NaCl solution,-application of a lower level of polarization during the test, either -1.0 or -1.1 VŒ CCS instead of Œ 1.4 V-CCS for the standard test condition,-addition of sand to simulate a moist soil rather than a fully immersed condition,-elevated temperature to examine the effect of temperature.A standard cathodic disbondment test was run for direct comparison.
L52056 Enhancement of PRCI Thermal Analysis Model for Assessment of Attachments
Authors: Bruce  , Yushanov
Published: August 2023

Welds made onto in-service pipelines tend to cool at an accelerated rate as the result of the flowing content"s ability to remove heat from the pipe wall. These welds are therefore likely to have high heat-affected zone (HAZ) hardness values and to be susceptible to hydrogen cracking. The use of thermal analysis modeling allows welding parameters (i.e., required heat input levels) to be selected based on anticipated weld cooling rates. Both the Battelle model and the recently developed PRCI Thermal Analysis Model for Hot Tap Welding assume that the pipe material is the most susceptible material being welded. Some attachments (e.g., hot formed fittings, etc.) have a significantly less favorable chemical composition (i.e., higher carbon equivalent level) than the pipe material. As a result, for some in-service welding applications, the attachment material may be more susceptible to cracking than the pipe material.

Modifications were made to the finite-element solver of the PRCI model to enable hardness prediction in both the pipe and attachment material. The source code for the modified finite-element solver was provided to Technical Toolboxes - PRCI"s commercial partner for software marketing and distribution. The required modifications to the user interface were also developed. In addition, user interface modifications required to rectify a number of faults that were identified and to improve the user interface were also developed. The incorporation of these enhancements and improvements, which are described herein, will require modification by Technical Toolboxes of the Visual Basic-based version of the software that is currently being marketed (V4.2.1). Following the incorporation of these enhancements and improvements, validation trials should be carried out.
PR-186-073508-R01 Environmental and Stress Factors that Produce SCC in Existing Ethanol Facilities
Authors: Beavers  , Gui  , Sridhar
Published: August 2023

The potential exists for stress corrosion cracking (SCC) of carbon steel pipelines transporting fuel grade ethanol (FGE) and FGE- gasoline blends. The objective of SCC 4-3 Phase 2 was determine if inhibitors are effective in preventing SCC growth under more realistic field conditions than those found in the slow strain rate (SSR) tests performed previously. The results of the research demonstrated that: 1. Un-notched SSR test results generally correlated well with the results of the crack growth tests using precracked CT specimens, although the latter test technique was somewhat more aggressive. 2. The notched SSR test technique was so aggressive that it was not useful for screening SCC inhibitors. 3. E-50, prepared with a simulated FGE was consistently more potent as a cracking agent than SFGE. 4. Some commercial inhibitors were effective in inhibiting ethanol SCC under many of the test conditions. 5. The commercial inhibitors, in general, were less effective in E-50 than in SFGE. 6. Ammonium hydroxide, at a relatively low concentration, was by far the most effective inhibitor evaluated. 7. For one commercial inhibitor, a higher concentration was needed to inhibit SCC in one lot of corn based FGE than in SFGE. 8. Water inhibited, but did not completely arrest, SCC in the crack growth tests in SFGE. 9. Sustained crack growth was observed in SFGE in which no chloride was added. 10. Evidence of loss of inhibition, at low concentrations, was observed in an inhibition scheme for batching of FGE with gasoline in which a high initial dose, followed by a low maintenance dose was used.
L52337 Weld Design Testing and Assessment Procedures for High Strength Pipelines
Authors: Tyson
Published: August 2023

This is the last report of a�c reports detailing the small-scale mechanical testing performed on the trial welds in this consolidated program. This report summarizes and compares the results of all of the mechanical tests applied primarily to welds of rounds 1 and 2, including tensile results and their correlation with microstructure, Charpy test results, conventional (through-thickness-notched) toughness tests, and low-constraint toughness tests.

The reports contains a summary of the mechanical properties of the experimental single and dual torch GMAW-P X100 pipe welds prepared for this consolidated program. It summarizes the detailed results reported in Final Reports 277-T-05, 277-T-06 and 277-T-07. The intent of this summary is to provide insight and understanding of the significance of the results and the implications for mechanical testing of weldments to extract properties essential for strain-based design (SBD).
PR-277-103700-R01 Guidelines for Preventing Underground Facility Damage as a Result of HDD
Authors: Puckett
Published: August 2023

Despite the advances that have been made in the horizontal directional drilling (HDD) industry over the past 40 years, damage to existing underground facilities as a result of HDD operations remains a serious concern. HDD poses a unique risk of damage to underground facilities due to the fact that obstructions along the drilled path are seldom evident during construction. HDD operations also have the potential to cause damage even when a seemingly adequate separation distance is maintained between the drilled path and existing facilities. As a result of these issues, damage prevention practices in the HDD industry are becoming increasingly important as facility corridors become more congested. In order to effectively reduce the potential for facility damage resulting from HDD operations, it�s important for those involved in HDD design and construction to understand why facility damage can occur and how it can be prevented. The objective of this report is to present guidelines that will both reduce the potential for damage to existing facilities during HDD operations and improve the accuracy with which the location of completed HDD installations is documented.
L52349 Essential Welding Variables - Development of Optimized Welding Solutions for X100 Line Pipe Steel
Authors: Rajan
Published: August 2023

This is the sixth in the series of nine topical reports that detail the research leading to the development of the optimized welding solutions for X100 line pipe steel. Collectively, these reports have highlighted the essential welding variables and the methodology for monitoring and controlling them.

In this report, the essential welding variables are examined in greater detail. Initial identification of the primary variables was accomplished using a thermal-microstructural model. The outputs from this model were used in developing a statistical test matrix for welding experiments in flattened X100 pipe to validate and corroborate the identification of the primary welding variables.
L00000 Effect of Pipe Roughness on Orifice Metering Accuracy
Authors: Bean Howard , Murdock J.W.
Published: August 2023

This report describes research done to determine the effect of pipe roughness on orifice meter accuracy. This report specifically analyzes a four-inch diameter tube. Results of the study conclude that tubes of this size can be honed without affecting their accuracy. As an overall conclusion from this and previous studies in normal metering practice, the honing of tubes will not change the coefficient in any pipe size. It is recommended that honing or polishing of meter tubes is permitable and further investigation of roughness effect is no necessary.
L52341 Summary of Publications-Single-Edge Tension SE(T) Tests
Authors: Tyson
Published: August 2023

A low-constraint test designed to reduce unnecessary conservatism in the measurement of toughness for use in the assessment of flaws in pipeline girth welds has been developed. The test was first proven on nominally homogeneous material (pipe base metal) to check the practicality of the procedures and to study the effects of the controlling geometric parameters (a/W, etc.) on toughness. The intent of this report is to reference the publications resulting from this work and to summarize the principal conclusions.

This is the third report of a series of seven technical 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 technical report 277-T-08. The present report highlights the principal results of preliminary application of the toughness test procedure that have been published in a series of papers in the open literature.
L51442a Field Measurement of Liquid Holdup in Commercial Two Phase Flow Pipelines A
Authors: Gregory
Published: August 2023

This report contains the results of a research program in which gamma ray densitometers were used to make direct measurements of the liquid volume fraction in two and three phase pipelines. The calibration and analysis procedures that were developed for the densitometers are described. Also included are the results of several special tests to investigate the sensitivity and operating characteristics of these instruments.Test were conducted at one oil field and three gas fields for pipe diameters ranging from 4 to 16 inches. The project concluded that the densitometers can provide useful data from two phase pipeline even when the liquid hold-up is very small. However, It is recommended that they not be used to obtain liquid holdup data for three phase pipeline, except under conditions described in the report.
L22276 Study of Exhaust Emissions from Natural Gas Pipeline Compressor Engines
Authors: Urban  , Springer
Published: August 2023

This study builds on the results of a baseline emissions survey conducted by the Southwest Research Institute and sponsored by the American Gas Association. The baseline survey obtained a wide variety of data on the operating conditions and emission rates of gas turbines and reciprocating engines at rated speed and load under on-site field conditions. In this study, the results of the survey are used to estimate the role of gas transmission equipment as a source of NOx, CO, and hydrocarbon emissions, and to assess current control methods for reducing NOx emissions. This study only involves reciprocating engines and gas turbines over 1,000 horsepower.
L51407b Pipeline Nomograph for Point Sources B
Authors: Unknown Author
Published: August 2023

This item consists of two nomographs plotting pipe thickness, modulus of elasticity, equivalent charge weight, standoff distance, and circumferential or longitudinal stress. The two graphs cover different ranges of equivalent charge density and standoff distance. The equivalent energy release for several different types of explosives are provided.
L51442b Field Measurement of Liquid Holdup in Commercial Two Phase Flow Pipelines B
Authors: Gregory
Published: August 2023

This report contains the results of a research program in which gamma ray densitometers were used to make direct measurements of the liquid volume fraction in two and three phase pipelines. The calibration and analysis procedures that were developed for the densitometers are described. Also included are the results of several special tests to investigate the sensitivity and operating characteristics of these instruments.Test were conducted at one oil field and three gas fields for pipe diameters ranging from 4 to 16 inches. The project concluded that the densitometers can provide useful data from two phase pipeline even when the liquid hold-up is very small. However, It is recommended that they not be used to obtain liquid holdup data for three phase pipeline, except under conditions described in the report.
L51422 Welding REM Treated PL Steels with GMAW-S Process
Authors: Li
Published: August 2023

The fundamental weld metal deposition behavior of the short-circuiting GMAW-S process has been investigated for changes in electrode composition and polarity, shielding gas composition, welding speed and heat input (voltage and current). The results have been applied to analyzing the arc physics and resulting metal deposition characteristics when welding rare earth (RE) treated pipeline steels.
L51481 AE Monitoring by Experimental and Theoretical Evaluation of Wave Propagation
Authors: Sancar
Published: August 2023

A detailed analytical model of a buried pipeline was derived and numerically exercised to evaluate frequency spectra, group velocities, amplitude ratios, axial power flow parameters and soil damping coefficients to determine parameters regarding optimum AE inspection. The analytical and experimental results of this program are described in this report.
L51433 Plume Rise from Gas Turbines and Reciprocating Internal Combustion Engines in Gas Transmission
Authors: Balentine  , Williamson  , Zubrick  , Coerr
Published: August 2023

Measurements of exhaust plume rise from a gas turbine and three compressor engines were made and the observed results were compared with predicted plume heights from existing plume rise models. Alternative plume rise models were developed based on the observed data for use in estimating gas turbine and compressor engine plume rise. The present study was designed to determine the most accurate and suitable plume rise model or models to be used with gas turbines and reciprocating engines used in the gas transmission industry.

Zip file contains field test data and test protocol.
L51546 Field Testing Criteria for Cathodic. Protection of Buried Pipe
Authors: Barlo
Published: August 2023

(Interim report) Summarized the interim results of three years of field tests of the cathodic protection criteria for 13 field sites. Tests are planned to continue for a total of five years. Results to date indicate current criteria are in most cases conservative.
L51500d Crankshaft Stress Reduction through Improved Alignment D Vol 4
Authors: Smalley
Published: August 2023

Four-volume report covering a two-year investigation of factors affecting crankshaft stress due to engine alignment conditions including foundation/grouting effects, unpredictable thermal growth and case load deflections. Two volumes are year-end reports, and two volumes are topical reports covering field tests (one sole-plate mounted and one grouted engine).
L51535 Girth Welding Line Pipe Made of Stainless Steel Either Solid or Internally Clad - Phase II
Authors: Hale
Published: August 2023

Girth welds were produced using a manual CTAW procedure in solid and clad stainless steel line pipe. Corrosion behavior in CO2 and NaC1 solution simulating wet gas was evaluated.Girth Welding Line Pipe Made from Stainless Steel Either Solid or Internally Clad -- Phase II. See also L51498.
L51547 In-Situ Detection of Disbonded Coating
Authors: Jordan
Published: August 2023

Reports on an industry survey to determine frequency of disbonded coating. Using represented disbondment, tests were conducted using modified EMAT pigs to detect problem area. Laboratory testes were encouraging, but field tests indicated additional development work was necessary.
L51429 Thermodynamic Models of Gas Turbines and Centrifugal Compressors
Authors: MacIsaac B.D.
Published: August 2023

Gas Turbine and Centrifugal Compressor Engine Health Monitoring Computer Program Supporting software package to Development of Thermodynamic Models of Gas Turbines for Pipelines-Summary Report. Consists of engine health monitoring program stored on magnetic tape. Coded in ANSI Standard 1966 Fortran with some codes (to drive the lineprinter and video terminal when graphics are being produced) specific to the project computer system (DEC RT-11). Tape contains 21 files
L51455 Base Reference Temperature
Authors: Gibson  , Maxey
Published: August 2023

Overall objective of this program is to develop a method of determining the base reference temperature for a buried pipeline. This report presents Phase I of the program which consisted of a literature review and industry survey.
L51531 Evaluation and Testing of Leaks from Available Types of Threads Used in Gas Storage Operations
Authors: Schmidt
Published: August 2023

Technical report on a project intended to quantify natural gas losses in storage wells attributable to threaded casing connectors. Tests were conducted on a simulation apparatus of 5.5-inch K-55 casing using API 8 Round, Long, and Short threaded connections and a representative premium connection.
L51573a Pipe Connection Methods and Effects on Deepwater Construction
Authors: Litzelfelner
Published: August 2023

A study to review and evaluate the various mechanical pipeline connectors currently available for J-curve pipelay methods offshore. The connectors were compared by listing the advantages and disadvantages of each. A test program to evaluate connectors was developed.
L51596 Flux Distribution - Pipeline Flaws
Authors: Lord
Published: August 2023

Describes the use of finite element analysis to carry out magnetic flux leakage studies intended to optimize the design of pipeline flaw detection vehicles based on this technology. The report provides predictions based on this approach supported by experimental measurement for a wide variety of defect shapes.
L51592 Development of Pipeline Stability Design Guidelines for Liquefaction and Scour
Authors: Litzelfelner
Published: August 2023

Documents and evaluates the current state of the art for assessing offshore pipeline stability for both liquefaction and scour conditions. Includes a PC-based computer program to assess pipeline stability conditions. The PC program includes a soil liquefaction program, a scour program, and a data base of referenced reports. 3 diskettes
PR-309-06201-R01 Pre-Production and Production Ion Sense Hardware and Cylinder Level Sensing
Authors: Beshouri  , Huschenbett
Published: August 2023

In 2001, the Compressor and Pump Station Technical Committee (CAPSTC) recognized the importance of cylinder level sensing and control to minimize NOx emissions while maintaining optimum engine performance, therefore, a CAPSTC member brought the concept of ion sense to the committee as an alternative to fiber optic pressure sensors for continuous combustion performance monitoring. Derived from automotive technology, ion sense utilizes post ignition ionization measurements from a standard spark plug to monitor the combustions process. Based on successful feasibility tests at Colorado State University�s (CSU) GMV-4, the commercialization team focused their efforts on developing a product for Open Combustion Chamber (OCC) Two Stroke Cycle (2SC) lean burn engines. By 2010, the commercialization team of Advanced Engine Technologies Corporation (AETC), Altronic, and Mecel developed commercial hardware and conducted extensive mapping and long term testing on three different 2SC OCC engines operated by three different companies.
PR-218-104509-R01 Field Validation of Surface Loading Stress Calculations for Buried Pipelines
Authors: Zand Benjamin
Published: August 2023

The objective for this two phase project was to validate surface loading criterion for pipelines with shallow burial. This is the report of the first phase of this project which focused on field measurements of the stress in shallow buried pipe while it is being crossed by heavy equipment. During the second phase, this data will be compared with the predictions of the most prevalent models currently used for surface load stress analysis for pipelines with shallow cover. The objective of the two phase study is to have a validated model for surface loading of shallow buried pipe. In the phase I, Kiefner and Associates, Inc. instrumented three buried pipe segments at the Spectra Energy Berne Station in Southeastern Ohio. The station was PRCI approved. The line was instrumented with strain gauges in order to make direct measurements of the stress in the pipeline as heavy equipment crosses over the pipeline. The data generated in this first phase and, if necessary, additional data from a second phase will be compared with the current Spangler, Iowa and CEPA models used for surface load stress analysis during the second phase.
PR-343-14607-R01 Miniaturized Gas Chromatography and Gas Quality Sensor
Authors: Hall  , Brown
Published: August 2023

In natural gas transmission and distribution, many metering stations utilize gas chromatography to ensure the gas complies with the pipeline�s gas quality tariff provisions and to determine the chemical energy content of the gas for billing purposes. It is also used as a check on the operation of gas ultrasonic flowmeters through a calculation of the speed of sound in the gas. Because of limitations on existing gas chromatographs (GC�s), including high installed cost, analysis time, carrier gas consumption and others, there is a desire to consider alternate technologies for natural gas analysis. PRCI has sponsored a study of technologies that utilize the variation in absorption/scattering of optical wavelengths by different molecules. The purpose of this study is to extend that study to the use of additional technologies, such as MEMS (Micro-Electro-Mechanical Systems). This is not a new approach, but recent advancements offer a greater possibility of achievement of the desired goals than in the past. This study reviewed and evaluated work in process with MEMS technology to provide a smaller, less ex-pensive, lower-power and faster GC that can be utilized in a Class 1 Division 2 area. Developments at both commercial firms and in university MEMS research programs have been included. Since there have been several programs to evaluate �energy meters� that attempt to measure gas quality by calculating the BTU content of a gas sample, this study focused on micro-GC�s that can make a much more precise measurement of gas quality.