bluuebunny/crossref_metadata_2025 huggingface dataset:
L52058 Evaluation of Preheat Requirements for In-Service Welding
Authors: Yunovich  , Thompson
Published: August 2023

Accurate control of preheat is often required during pipeline welding, both for new construction and for in-service welding (repairs and hot tapping). Conventional methods of applying preheat, such as gas torches, are difficult to control, and can be slow and inefficient. Additionally, the rapid cooling associated with in-service pipelines tends to limit the effectiveness of any form of preheat. New equipment for induction preheating offers the possibility of achieving excellent levels of control together with high thermal efficiency, rapid response, and minimal disruption of accessibility to the weld joint.

The objective of this project was to develop guidelines for preheating welds made onto in-service pipelines and determine the capabilities and limitations of methods of applying preheat using equipment suitable for in-service applications. Field trial experiments were carried out on a 34-in. (863.6-mm) diameter × 0.281-in. (7.1-mm) wall thickness crude oil pipeline to compare the performance of induction preheating and flame preheating under actual in-service conditions. In general, induction heating was found to be much more effective than flame heating. The field trial produced some interesting insights into preheating for in-service welding applications in general and the use of induction heating for this purpose in particular. Guidance was developed pertaining to the appropriate preheat.
L51814 Survey Of Dry Low NOx Combustor Experience
Authors: Simmons
Published: August 2023

Air pollution has become a major public issue and it is now evident that unburned hydrocarbons, CO, and NOx must meet increasingly restrictive standards. The emissions of nitrogen oxides by gas turbines are of concern because of their high toxicity and their role in the formation of photochemical smog. The formation of NOx occurs in a gas-fired gas turbine when combustion temperatures exceed a critical level for sufficient time to allow atmospheric nitrogen and oxygen to combine. For those gas turbine applications where steam or ultra-pure water are readily available, then steam or water injection are preferable NOx control strategies. Because these attributes are usually not available at pipeline compression stations, the turbine operators in the pipeline industry have chosen to control emissions by a dry combustion process. An alternative would be a catalytic reduction of the NOx generated in the exhaust gas but this requires an investment in SCR hardware and continuous use of ammonia, which adds to operating costs. Historically, dry low emissions (DLE) systems have experienced a greater than expected number of start-up problems as new products were introduced to the marketplace. A need of the gas pipeline industry is to identify the operating problems experienced with DLE systems, to link these problems to their most probable cause, to estimate costs incurred, and to glean strategies for avoiding future problems.

A comprehensive PRCI sponsored survey of operators and manufacturers was completed which provides assistance to gas turbine operators in making NOx control procurement decisions and for budgeting operations and maintenance costs. This first ever detailed study provides information on typical operating costs and problems incurred with the currently operating DLE systems and serves as a guide for individual companies in the selection of cost effective low NOx combustion systems from available components offered by the OEM and after-market suppliers. The information developed by this report is intended to guide operators in estimating maintenance and repair costs to establish a lifetime cost of operation.
L51648 Fitness-For-Purpose Assessment Procedures for Sleeve and Branch Welds in Pipelines
Authors: Gordon  , Dong
Published: August 2023

�One of the major problems associated with developing fitness-for-purpose procedures for sleeve and branch welds is the prediction of the local stress distribution at the welds. Since the presence of a sleeve or branch will increase the local stiffness of the pipe and give rise to local stress concentration effects, the stress distribution at sleeve or branch welds cannot be readily estimated using simple stress analysis.

This project studied the structural behavior of sleeve and branch connections in pipelines. Because these connections create local stress concentration effects, where several potential crack orientations need to be considered, the stress distribution at these points cannot be estimated using simple stress analysis. In this research, finite element analyses were performed to determine: (1) the local stress distribution resulting from internal pressure and remotely-applied tensile and bending loads at sleeve and branch welds; (2) the effects of sleeve thickness and length; (3) the effect of poor fits (i.e., gaps between the pipe and sleeve); and (4) the effect of a through-wall crack at sleeve and branch welds in pressurized pipe.
L51751 Evaluation of Low Hydrogen Welding Processes for Pipeline Construction in High Strength Steel
Authors: Jones
Published: August 2023

As the use of higher strength and thicker walled pipe becomes more prevalent, the procedures that would normally guard against hydrogen cracking when welding with cellulosic electrodes, become less effective and it has become necessary to investigate the use of alternative low hydrogen consumables. Low hydrogen manual welding processes, suitable for pipeline girth welding, have been available for some time for the lower strength pipe grades, and latterly, for high strength pipelines (up to and including X80). Despite their availability and advantages in terms of reduced crack susceptibility, they have been rarely used in production up to the present time. Basic coated shielded metal arc (SMA) electrodes, suitable for vertical-down welding, are produced by some manufacturers at the strength level required for both the root welding and filling of pipeline girth welds. Self-shielded flux-cored wires (SSFCA) are also available for both root and fill welding, and in addition to the low hydrogen levels, these have the advantage of increased productivity. Both of these processes require different methods of deposition compared to welding using cellulosic electrodes, which necessitates specialized training of welders. It is thought that this, along with doubts concerning the reliability and speed of the processes in site conditions, has made contractors reluctant to adopt them. Furthermore, there was a dearth of independently produced information on the welding production performance of low hydrogen processes.

The objectives of this work was to generate data to enable users to make an informed judgement regarding the practical application of low hydrogen processes. Furthermore, it was intended to develop improved root welding procedures, which had been recognized as being significant process limitation. A further objective of this work was to collect data to permit an informed choice when choosing low hydrogen welding processes for modern high-strength steel walled pipe. The performance of low hydrogen vertical down electrodes (L4VD) and solid and flux cored wires for welding X80 linepipe is assessed with regard to ease of welding, productivity and weldment mechanical properties in comparison to cellulosic electrodes.
L00310 Movement of Underground Water in Contact with Natural Gas
Authors: Katz
Published: August 2023

This research was initiated to bring together the knowledge required to predict water movement in gas storage operations. The goal was to develop calculation procedures, which could be utilized directly by engineers in charge of the operation of storage fields. Engineering studies of water drive occurring in gas storage reservoirs pointed out the need for more definite procedures of calculation because of the cyclic nature of the storage operation.

The first year of the project was devoted to developing equations and procedures to ascertain, analyze and interpret the nature and the extent of water drive for various geometric models. Solutions to the equations and procedures for calculation were developed during the first year. Digital computing techniques were developed to permit the handling of the large number of calculations required by the nature of the pressure cycles. During the second year, field data were collected and analyzed for several storage and production operations. The field data were employed to compare predicted performance with observed behavior. These calculations required refinements and extensions of the equations developed during the first year. The organization of the entire material pertaining to the mathematical treatment of water drive gas reservoirs, applications of filed data, discussion of results and general conclusions were undertaken during the third and concluding year of the project.

This monograph covers the full range from the calculation procedures for practicing engineers to the complex mathematical developments required in deriving the relationships used and the computer programs for machine computations. This monograph is prepared for three groups: (1) the reservoir or field engineers for gas storage and producing operations, (2) computing center personnel in gas companies who are likely to become involved in water movement calculations, and (3) research engineers working on reservoir phenomena, who desire to find in one volume a summary of pertinent unsteady-state flow equations and their solutions.
L51627 Large Scale Collapse Testing
Authors: Wilkowski  , Scott  , Maxey
Published: August 2023

The design of deep water pipelines must consider external pressure loading which is applied to the line during construction or in service when the line is evacuated. A collapse failure can occur due to this external pressure alone or external pressure in combination with tension or bending loads which are imparted to the line during construction. Thus, there is an incentive for research to more accurately define the failure envelope for combined external pressure, bending, and tension for offshore pipelines.

Previous work concentrated on small scale testing and theoretical work. The purpose of the work in this project was to perform large scale tests to verify the previous work, and in particular to test a limited amount of seam welded Double Submerged Arc Welded (DSAW) pipe to compare with widely available seamless data. Deepwater gaslines normally are in the 16-24\ size range where DSAW and ERW (electric resistance welded) are the only available manufacturing processes. ERW pipe was not studied in this project.
L51621 Hydrogen-Related Failures at Mechanically Damaged Regions
Authors: Cialone H. , Williams D. N. , Groeneveld T. P.
Published: August 2023

Leaks attributed to hydrogen-stress cracking (HSC) initiating in regions of mild mechanical damage have been reported in cathodically protected pipe lines constructed from high-strength, microalloyed, controlled-rolled steels. The hydrogen is believed to be present in service from the cathodic potential applied. Laboratory studies were initiated to determine the factors that contributed to those unexpected failures. Strain aging at ambient temperatures as a result of deformation introduced during the mechanical damage, was found to be a significant factor. Smooth-bar specimens that were strained and then aged failed by HSC within one week, whereas specimens that were not strain aged did not fail by HSC. Result: The findings of this research indicate a potential sequence of events which may lead to hydrogen-related failures in regions of mild mechanical damage: (1) Following the damage, ambient-temperature strain aging which promotes sensitivity to HSC takes place in the mechanically damaged region, in a surface layer of the pipe wall which has been subjected to a critical level of strain. The time period for this step would be on the order of several years. (2) Electrochemical conditions which promote hydrogen charging develop at the pipe surface from the cathodic current applied (or possibly corrosion). (3) Local stresses in the mechanically damaged region are elevated above the threshold stress for HSC by the moderate stress concentration provided by the mechanical damage. For the X70 pipe studied, the stress elevation should be at least 20 percent above the nominal hoop stress. (4) An HSC crack initiates and grows in the strain-aged surface layer. (5) The crack propagates further by HSC, through the non-strain-aged portion of the wall, as a result of the high stress concentration at the crack tip. (6) When the crack grows to a critical depth, it propagates rapidly through the wall by overload and causes a leak.
L51690 Evaluation of Modern X-70 HFER Line Pipe
Authors: Groeneveld
Published: August 2023

In recent years, several pipe mills have produced heavy-wall, large diameter pipe from plates of microalloyed steels that were controlled-rolled to develop properties to meet the API 5LX Grade 70 or Grade 80 requirements and that were electric resistance welded (ERW) using advanced techniques. The use of advanced electric seam-welding practices on the steels produced using advanced steel making and processing methods offers the possibility of obtaining high strength line pipe at a lower cost than pipes produced from similar steels but with double submerged arc seam welds. The present study was undertaken to evaluate the properties of the pipe body and the ERW seam-weld region of a recently produced heavy-wall X70 line pipe. This report describes the evaluation of that pipe. The mechanical properties of the weld zone from this pipe were evaluated and reported under Task 18-89. Those data are included in this report. A high-frequency electric resistance welded (HFERW) X70 line pipe was evaluated to assess the strength properties, fracture behavior, thermal stability, and susceptibility to environmentally induced degradation that may affect its behavior in gas transmission service. A 20-inch-(508 mm)-diameter by 0.500-inch-(12.7 mm)-wall high-frequency, electric-resistance-welded (HFERW) X70 line pipe was evaluated to assess the strength properties, fracture behavior, thermal stability, and susceptibility to environmentally induced degradation that may affect its behavior in gas transmission service. The steel from which the pipe was produced was processed using advanced steel-making practices that resulted in a low sulfur content and was microalloyed with Cb, V, and Ti. The steel was controlled rolled with 75 percent of the rolling reduction being accomplished at temperatures below 1418 F (770 C); the finishing temperature was 1328 F (720 C) and the steel was hot coiled after finishing. The seam weld was produced by high frequency electric resistance welding and the seam weld region was post-weld normalized.
L51803 Failure Criterion for Stress-Corrosion Cracking in Pipelines
Authors: Leis  , Mohan
Published: August 2023

Failures due to stress-corrosion cracking (SCC) generally involve several adjacent, parallel, deep cracks that because of their proximity coalesce to form long flaws, which can cause ruptures.Recent studies indicate that such multiple flaws cause a local increase in compliance as compared to a single crack that represents the largest of the cracks involved.This means that the failure pressure for such a group of cracks can be poorly represented by a single flaw failure criterion, such as the Pipe Axial Flaw Failure Criterion (PAFFC) developed for the Pipeline Research Council International, Inc.

The objective of this project was to develop a failure criterion for the multiple flaw situations typical of SCC based on available literature data for a repeating pattern of cracks (a regular array of cracks). This report begins with a discussion of predicted failure pressures for several typical field failures due to SCC. This discussion clearly demonstrates significant errors in predicted failure pressure for the multiple cracking typical of SCC when the failure pressure is predicted in terms of available single-flaw failure criteria for part-through-wall flaws in pipelines. This is followed by an analysis based on available literature data. It is shown that the literature data fail to represent the essential features of typical patches of cracks that control SCC failures. Analysis representing realistic cracking patterns is then introduced and used in conjunction with PAFFC to show that very accurate predictions can be made if the typical nature of the SCC patch is embedded in the failure criterion.
L51758 Non-Destructive Assurance of Quality of Heat-Treated Fittings
Authors: Veer J. van der , Wortel J. van
Published: August 2023

Sometimes heat treated components fail to pass the specified minimum mechanical requirements (yield strength, Charpy V-notch toughness). The influence of the complete heat cycle on the end results is not well understood and without a N.D.T. method for determining these properties the pipeline companies have difficulty in determining acceptable and non-acceptable individual components. In the quality control process for heat treated components, it is important to have a non-destructive testing technique available for predicting the yield strength and, if necessary, Charpy V-notch properties. In order to quantify the influence of the thermal cycle on the essential mechanical properties of plate material FeE355 and evaluate a promising N.D.T method for predicting yield strength and toughness, five heats of plate material FeE355 received ten different normalizing heat treatments (combinations of three different austenitizing temperatures and 4 heating/cooling rates). The heat treatment conditions were chosen to obtain a wide range of ferrite grain sizes/yield strengths. Together with the as-delivered conditions 55 conditions of plate material FeE355 were examined. Theexamination included:- Ferrite grain size measurements directly on the outer surface of the material (after removal of the decarburized zone) by means of replicas.- Tensile tests at 20�C, in twofold for all 55 conditions.- Charpy V impact tests at three temperatures, each in threefold for all 55 conditions.- Ferrite grain size measurements on cross sections of one of the threaded ends of all 110 tensile specimens.
L51678 Repair Welding on the Residual Stress Distribution and Fracture Toughness in Girth Welds
Authors: McGaughy
Published: August 2023

This program completes a 2-year study investigating the effects of SMAW repair welding on the residual stress distribution and fracture toughness of pipeline girth welds. This second year of work, under contract PR-185-9104, has studied double part-wall, standard full-wall and modified full-wall repairs on GMA fabricated girth welds. The modified repair used a stringer bead technique in an effort to enhance the toughness of the repair region. The results of this study indicated the repair welds produced yield magnitude axial residual stresses on the inside and outside pipe surfaces. The hoop residual stresses were approximately equal to half-yield magnitude the inside surface while they were nearly zero in the weld on the outside surface of the pipe. The stress distributions were nearly identical regardless of the type of repair. Fracture toughness was reduced in the double part-wall and standard full-wall repairs. However, the modified full-wall repair produced toughness levels which exceeded the toughness of the original girth weld. This was attributed to grain refinement in the modified repair produced by the stringer bead technique.
L51543b Evaluation of Cost-Effective Measures to Comply with Storage Tank Regulations Vol 2
Authors: Tucker
Published: August 2023

Assesses the impact on the natural gas industry of recently proposed EPA rules specifying technical standards and financial responsibility covering buried tanks used to store certain petroleum products or chemicals. Reviews leak detection and monitoring methods, tank piping options, installation practices, and generate response procedures.Vol. I only approved for publication.
L51927 Guidelines for the Seismic Design and Assessment of Natural Gas and Liquid Hydrocarbon Pipelines
Authors: Honegger  , Nyman
Published: August 2023

Much of the current seismic practice can be traced to research conducted in the 1970s to develop design criteria and procedures for the Trans-Alaska oil pipeline. The major natural gas pipeline operators in California have implemented many of the procedures in these guidelines, in one form or another. The recognition of credible seismic hazards in other parts of the United States has been the primary driver for extending current practices in California to the rest of the United States. The experience in designing pipelines in seismically active regions of the United States has also provided a basis for specifying pipeline seismic design practices in other parts of the world.

This project was initiated to provide current seismic guidelines for the design and assessment of natural gas transmission pipelines. These guidelines were refined using two rounds of review by outside technical experts in 1999 and 2000. The PRCI ad hoc steering group for the project also provided regular input regarding the scope and technical content for these guidelines. A decision was made in late 2000 to expand the scope to liquid hydrocarbon pipelines (crude oil and refined products) based upon the identical analytical treatment of seismic design and assessment of these types of pipelines.
L51878 Methods for Assessing Corroded Pipeline-Review Validation and Recommendations
Authors: Fu
Published: August 2023

An assessment of the remaining strength of corroded line pipe is generally accomplished using the ASME B31G method and RSTRENG methods. These methods were developed using an early fracture mechanics relationship for toughness-independent failure of pressurised pipes and were empirically calibrated against a database of around 80 full-scale burst tests for thin wall pipes, dominated by pipes of grade B and grade X52. Applications of these methods to modern higher toughness pipe materials have not been fully justified. Neither of these methods is able to assess the significance of interactions between adjacent corrosion defects. Considerable effort, funded by Pipeline Research Council International, Inc. and by various industry groups, in particular in Europe, has in recent years addressed full-scale testing, analytical and numerical investigations, and the development of improved assessment methods.

This report presents the results of a comparative review of a number of existing and newly developed methods for assessing corroded pipelines and a proposed methodology for the development of integrated corrosion assessment guidelines. This study was funded by the Line Pipe Research Supervisory Committee of Pipeline Research Council International, Inc. (project No. PR-273-9803) and was carried out jointly by BG Technology (United Kingdom), Battelle Memorial Institute (United States of America) and Shell Global Solutions (the Netherlands). BG Technology was the lead contractor.
L51760 Low-pH SCC-Mechanical Effects on Crack Propagation
Authors: Chell
Published: August 2023

The objective of this project was to determine the roles and synergistic effects of pressure, pressure fluctuations, and hydrotesting on low-pH stress corrosion crack (SCC) growth. The project consisted oth three tasks: 1) to prepare test specimens and experimental apparatus and to establish a standard test protocol for conducting cyclic load tests and analyzing the test data; 2) to evaluate the effects of frequency, R ratio, and waveform on SCC growth in low pH environments; and 3) to evaluate the influence of hydrostatic pipeline testing on subsequent SCC growth in low-pH environments.
L51622 The Chevron Notched Drop-Weight-Tear-Test Specimen
Authors: Maxey  , Barnes
Published: August 2023

This research is aimed at finding a new type of notch that would produce propagation data similar to that produced by the PC DWTT. High-toughness materials and materials that had previously been studied were used assuming that if the new notch worked on these materials it would be satisfactory for lower toughness materials. Several notch modifications were tried and most were no better than the standard pressed notch used in the API specimen.

A search for a new type of notch for the standard drop-weight-tear-test (DWTT) specimen has been completed. This new notch specimen is to replace the precracked DWTT specimen which has been shown to predict full-scale behavior but has received-little support from pipe manufacturers. The new notch is a chevron notch causing fracture initiation to occur at a machined point located at mid-wall thicknessand about 0.2 inch below the specimen edge (i.e., at the same depth as the pressed-in notch of the standard DWTT). No precracking or other severe prestraining, which may create strain aging problems, is required to produce the specimen. A good correlation was obtained between the chevron-notched DWTT and the Charpy V-notch specimens for conventionally rolled steels; this correlation effectively ties the chevron notched data to past fracture research data and to published correlations thatdescribe fracture in terms of Charpy upper-shelf energy. A procedure is included for preparing and conducting the Chevron notched DWTT.
L51884 Assessing the Remaining Strength of Corrosion Defects in Low Toughness Linepipe Materials
Authors: Beavers
Published: August 2023

One of the principal causes of failures of transmission pipelines is volumetric metal loss due to corrosion. Various methods such as ASME B31.G, RSTRENG and the LPC methods have been developed to assess the severity of corrosion defects. The methods have developed to the extent that they are recognized by standardization bodies and regulators. However, all the methods have been developed and validated on high toughness materials. There is a concern that these methods may give non-conservative results if they are used for low toughness materials. If this is the case, guidance is required on the limits of applicability of the current methods, and new methods are required for application to low toughness materials.

To investigate these issues, contractor objectives and scope were: To test a range of representative defects in low toughness linepipe; to assess the failure mode of these defects; to determine if current assessment methods can be applied to low toughness materials; and to identify the factors influencing the failure of corrosion defects in low toughness line pipe.
L52308 Temperature Logging as a Cavern Mechanical Integrity Test
Authors: Buchholz
Published: August 2023

This work documents case histories, develops an analytical solutions to predict a temperature decreases that occurs when gas leaks out of a well, and performs a computational fluid dynamics analyses of a generic gas well.
PR-244-114501-R01 Review of Compressive Strain Capacity Assessment Methods Final Report
Authors: Yoosef-Ghodsi  , Ozkan  , Bandstra
Published: August 2023

Buried pipelines subjected to non-continuous ground movement such as frost heave, thaw settlement, slope instability and seismic movement experience high compressive strains that can cause local buckling (or wrinkling), in which the pipe wall buckles like a thin cylindrical shell in axial compression. In a strain-based design and assessment framework, excessive local buckling deformation that may cause loss of serviceability, or even pressure containment in some cases, is managed by limiting the strain demand below the strain limit. The determination of compressive strain limit is typically performed by full-scale structural testing or nonlinear finite element analysis that takes into account material and geometric non-linearity associated with the inelastic buckling of cylindrical shells. Before performing testing and numerical analysis (or when such options do not exist), empirical equations are used to estimate the strain limit. In this report a number of representative equations were evaluated by comparing strain limit predictions to full-scale test results. Work prior to this study has identified the importance of key variables that have the greatest impact on the local buckling behaviour. Examples of these variables include the diameter-to-thickness (D/t) ratio, internal pressure and shape of the stress strain curve. The evaluation focused on how existing equations address these key variables, and the performance with respect to key variables and in different ranges.
PR-000-15208-R01 Reciprocating Engine Speed Stability as a Measure of Combustion Stability
Authors: Choquette
Published: August 2023

Combustion stability is an important factor to maintain long engine life, achieve maximum engine efficiency, and help assure compliance with emission limits. Continuous combustion pressure monitoring is the best method to reliably detect combustion instabilities (misfires, late fires, auto-ignition, and detonation) but it is currently installed on a small portion of the reciprocating engines used in the natural gas transportation industry. This project evaluates the potential of using the engine speed to detect and warn equipment operators of the presence of combustion instabilities. The intent is to provide a low cost diagnostic monitoring method that can be readily retrofitted on the existing population of reciprocating engines used in the natural gas transportation industry.
L51610 Pulsed Gas Metal Arc Welding of API 5LX-80 Pipe
Authors: Author Unknown
Published: August 2023

This research program was undertaken to investigate the use of the pulsed- gas metal-arc welding (PGMAW) process for the field, girth welding of API 5LX-80 pipe. The specific program objectives were as follows: Determine the optimum shielding in gas, commercial filler wire, and weld procedure for the PGMA girth 5LX -80 pipe welding in the 5G position of API to determine the mechanical properties of PGMA girth welds deposited in five, API 5LX-80 pipes manufactured by different pipe mills. This report summarizes the materials, equipment, and procedures used, the results obtained, a discussion of these results, and conclusions. The PGMAW welding procedures that were developed are considered field-ready and can be used reliably for field, girth-welding operations.
L51669 Diverless Pipeline Repair Clamp-Phase II
Authors: Miller  , Lane
Published: August 2023

The general goal of the work described herein is to develop the capability to remotely repair minor leaks in pipelines residing in water depths beyond diver work depths. Wells are now being drilled and production facilities are being installed in these water depths at the time of this writing. A wide range of pipeline damage is conceivable. At the least severe end of the spectrum, leakage due to local corrosion or a latent weld defect is possible. More severe damage such as that caused by anchor snagging or mudslides would likely require a more extensive repair capability. This research is limited to addressing repair of minor leaks repairable by installation of a split repair clamp.

This report summarizes the Phase II research effort and results. The objective of Phase I was to lay a foundation for eventual development of specific equipment and systems needed to implement the diverless repair clamp. Phase I may be characterized more as an investigation to broadly identify the state of the art in diverless operations and an effort to identify specific technology weaknesses for more detailed study. Another objective of Phase I was to develop generic mechanical concepts for the diverless repair clamp. The objective of Phase II has been to narrow the research focus to select a most favored concept for the mechanical arrangement of the clamp itself and to conceptually describe a preferred method for deploying the clamp. Specifically, the objectives of Phase II were: 1. Develop conceptual designs associated with two different repair philosophies; 2. Investigate and evaluate alternative fastening technologies and clamp-type sealing mechanisms; 3. Investigate installation-related issues such as pipe preparation, ROV capabilities, and ROV interfaces; and 4. Evaluate the two conceptual designs from both a technical and practical standpoint.
L52330 Development of an Active Air Control System
Authors: Grauer  , Chapman
Published: August 2023

Develop an active air control system that, when installed on a turbocharged-engine system, will reduce NOX emissions below the levels of the system alone. While the turbocharged-engine system allows the natural gas compression industry to decrease pollutant emissions via increased air flow, the physics of the system and the environments in which these systems operate restrict further advancements. A new model, the Charge Air Integrated Manifold Engine Numerical Simulation (CAIMENS). The CAIMENS model was used to:

Quantify the effects of charge air imbalance between cylinders in terms of NOX production;
Illustrate that an imbalance in mass air flow creates a one-to-one imbalance in corrected trapped equivalence ratio
Reveal a 5% to 12% imbalance in air flow present in the candidate Cooper GMV engine which correlated to a 65% to 92% imbalance in NOX production; and
Provide detailed information that led to the specification of a mass air flow (MAF) sensor coupled with an air flow balancer (AFB), comprising the Active Air Control (AAC) system.

The research team proceeded by working with the ERLE team to select cylinder liners for the NGML air flow bench, and then expanded the air flow bench from one cylinder to two cylinders. The specified AAC system was installed on each of the two cylinders. The research team then conducted a series of experiments to evaluate and fine tune the AAC system. The AAC system was able to correct up to a 12.4% air imbalance. The end point of the project was an AAC system that could, with some engineering effort, be applied to field engines.

Benefit: The resulting technology was an active air flow control system consisting of an AFB integrated with a MAF sensor. The AFB has characteristics analogous to that of a throttle plate used in a carbureted internal combustion engine.
L20169 Gas-Liquid Flow in Pipelines - Research Results
Authors: Dukler A. E.
Published: August 2023

This study was directed to develop improved design equations based on the most advanced current understanding of two phase flow. As described in this report, the research project consisted of three phases: 1) The development of a data bank of information representing the widest range of operating conditions; 2) The evaluation of existing correlations; and 3) the development of improved correlations for predicting pressure drop.
L51428 Development of Thermodynamic Analysis of Gas Turbines for Pipeline Applications Summary Report
Authors: McIsaac B.D , Saravanamuttoo H.I.H.
Published: August 2023

Discusses development of thermodynamic models of gas turbines applicable to gas pipeline operations and their use in the prediction of engine health from field measurements, assessment of operating efficiency, and diagnosis of engine deterioration. Four engine types are considered: two-shaft, simple cycle; two-shaft, regenerative cycle; three-shaft, simple cycle; and single-shaft, simple cycle. The engine health monitoring software developed, available separately, is also described. (L51429)
L51430 Thermodynamic Models of Gas Turbine and Centrifugal Compressor Phase III EHM Software Development
Authors: Stulen
Published: August 2023

This document reports on Phase III of the PR-154-128 contract (see also Catalog Numbers L51428 and L51429). Phase III is a computer programming design effort to incorporate the knowledge gained in the previous phases into programs to be used as diagnostic tools by pipeline companies. This manual contains a description of the development of computer program design for a gas turbine engine health monitoring system and instructions for its use in terms of general functions and specific applications.
L51543a Evaluation of Cost-Effective Measures to Comply with Storage Tank Regulations Vol 1
Authors: Unknown Author
Published: August 2023

Assesses the impact on the natural gas industry of recently proposed EPA rules specifying technical standards and financial responsibility covering buried tanks used to store certain petroleum products or chemicals. Reviews leak detection and monitoring methods, tank piping options, installation practices, and generate response procedures.Vol. I only approved for publication.
L51507 Field Weldability of High-Strength Pipeline Steels
Authors: Pargeter
Published: August 2023

This document reports on research to assess the weldability of a range of high-strength (X80 grade) line pipe steels using both small-scale weldability trials, the Welding Institute of Canada test, and full-scale girth welds. Hardness and tensile tests were used to assess strength, and Charpy V and crack tip opening displacement tests were used to assess toughness. Experimental results are provided and a number of conclusions are listed.
L51618 Assess Mechanistic Multiphase Methods Large Pipe Diameter
Authors: Johnson
Published: August 2023

Document draws upon the mechanistic model developed in earlier work (L51527 and L51611) and develops an assessment against independent laboratory data at large pipe diameter. The principal comparisons involve flow regime maps, pressure drop and liquid hold-up slug flow regime characteristics in one instance. The laboratory data are from three sources.Also see L51583. PR-172-810 II
L51639 Technology of Submersible Remotely Operated Vehicles
Authors: Gregory
Published: August 2023

Report represents a significant compendium of information on the capabilities and limitations of submersible remotely operated vehicles. It is an excellent primer for an outsider or new engineer. It is also a good review for the experienced engineer who must contract for ROV services to make an inspection or repair.
PR-164-093705-R01 Flaw Characterization Using Guided Waves
Authors: Sanderson  , Mudge
Published: August 2023

This project was intended to implement a guided wave flaw sizing technique and to ascertain its applicability to a range of pipe and flaw sizes. The report summarizes the modeling and analysis of laser mapped real corrosion data and presents the results of the experimental work on the performance of the guided wave technique.
PR-186-12204-R02A Effects of Ethanol on Pump Stations and Terminal Facilities - Materials Tables
Authors: Norfleet  , Beavers
Published: August 2023

These are the material compatibility charts for the related guideline document.
L51594 Review Pipe Integrity--Stress State Measurement Techniques
Authors: Gray
Published: August 2023

Presents a state-of-the-art review of the technologies available for stress measurement in buried pipelines and recommendations regarding further development of such technologies appearing to have favorable application for natural gas transmission service. The technologies are grouped in terms of internal inspection devices, devices requiring external access to the pipe, and those that may be inserted from the ground on the pipeline right of way.
PR-309-11202-R01 Field Demonstration Test of Advanced Engine and Compressor Diagnostics for CORE
Authors: Beshouri
Published: August 2023

Pipeline engines fitted with modem automation and control systems serve as ideal candidates for On Board Diagnostics (OBD) and Diagnostic Monitoring (DM). OBD is very effective for real time performance monitoring, pollution prevention and safety monitoring in the engine room. Diagnostic Monitoring (DM) extends the capabilities of OBD by using extensive historical data to characterize unit specific characteristics thereby dealing with engines as individuals. The work to date has focused on the development of a methodology to support real-time multiparameter analysis and crosscheck of engine data to quickly, accurately and precisely diagnose engine faults. The methodology uses a spreadsheet interface in combination with Mean Value Engine Models and an analytic table to perform the diagnosis. Field gathered data was then used Advanced Engine Technologies Corporation (AETC) then developed a playback simulator to replay data provided by PRCI members to test the methodology and confirm the ability to automatically detect engine and compressor faults.
L51626 Fracture Current Fracture Prediction Models for Girth Welds
Authors: Scott
Published: August 2023

Interpretive study of published and recent research on Engineering Critical Assessment techniques that relate to pipeline girth welds and compares the relative conservatism/nonconservatism of the API 1104 ECA technique with those proposed by other organizations and countries. Objective: provide greater confidence in these approaches/gain greater acceptance by regulatory bodies.
L51178 Cathodic Protection Monitoring for Offshore Pipelines
Authors: Payer
Published: August 2023

In the search for new sources of fossil fuels, the offshore gas and oil fields continue to be among the most promising areas. Corrosion protection for offshore pipelines is provided by a combination of coatings and cathodic protection. While this combination is similar to that for buried onshore pipelines, several characteristics of offshore environments favor effectiveness and lessen degradation of corrosion protection compared to onshore service. Coatings are not exposed to alternate wet/dry conditions or soil stresses. Effective cathodic protection is favored by both the relatively low resistance of seawater and marine soils and the uniformity of environment. The former enhances the range of influence of a protective anode, and the latter enhances desirable current distribution. These favorable characteristics are opposed by the generally more corrosive nature of marine environments and presence of concrete coatings for buoyancy control.

The objective of this study was to determine techniques to evaluate the cathodic protection status of existing and future offshore pipelines; to make a preliminary analysis of the probable success of each technique; and to recommend a program to develop and demonstrate feasibility of one or more of the techniques. The program was to survey existing information with emphasis on personal contact with those pipeline companies and cathodic protection companies engaged in the protection of offshore pipelines.
L51629 Users Manual-Field Validation of the Low-Frequency Eddy Current Instrument-Software Listings
Authors: Bruce  , Fiore
Published: August 2023

When an eddy current probe is placed near a conductive material, the alternating magnetic field from the probe causes electrical currents to flow in the material. These currents have associated with them their own magnetic field, which opposes the original magnetic field from the coil. The result is that the impedance of the probe is greatly reduced by the presence of the conducting material. If the conductor is also magnetic, as is normal steel, the situation is similar though slightly more complicated. Here, the impedance of the probe may be either increased or decreased depending on the permeability of the material and the frequency of the alternating field. Anything that affects the flow of current in the conductive material will also affect the impedance of the eddy current probe. For example, the electrical currents cannot flow through a crack but must flow around it. The alteration in the currents also changes the magnetic field produced by the currents and, consequently, the impedance of the probe. Normally, the impedance change caused by a defect is much smaller than that caused by the presence of the material in the first place, and measuring this small change requires a bridge circuit much like the balanced bridge used with strain gauges. The balanced bridge allows one to amplify the small changes in impedance caused by defects in the presence of the much larger change caused by the presence of the conductive and magnetic pipeline steel.

The LFEC instrument is constructed using an� IBM-AT compatible portable computer. Inside the PAC-386 are two plug-in circuit cards that turn the PAC-386 into an eddy current instrument. The first, also commercially available, is a Spectrum DSP56000 digital signal processing card, while the second is a specially-built interface card for the eddy current probe. The PAC-386 is a standard MS-DOS machine and will operate most MS-DOS software. In the discussion below, it is assumed that the user is familiar with the MSDOS operating system.
L51700 Damage Assessment Tool
Authors: Beavers
Published: August 2023

This report documents the requirements and possible configurations of a tool or system to inspect and assess the repairability of a damaged submerged pipeline. This work was done in conjunction with research to develop a diverless repair clamp for repairing small leaks in deep water pipelines.
L51663 Seam-Weld Quality of Modern ERW-HFI Pipe
Authors: Groeneveld
Published: August 2023

Major advances have been made in recent years in the production of electric resistance-welded (ERW) and high-frequency induction (HFI)-welded line pipe, particularly in the area of automated process control procedures designed to ensure uniform, high-quality seam welds. ERW/HFI pipe produced from microalloyed, controlled-rolled steels can be obtained in larger diameters and heavier wall thicknesses than were formerly available, and with reportedly excellent seam-weld quality as well as pipe body properties. Thus, it is feasible to consider the application of ERW/HFI pipe in a number of additional applications in gas-transmission lines. The lower cost of the ERW/HFI pipe compared with double submerged arc welded (DSAW) pipe of comparable size has resulted in increased interest in the greater use of this product.

This work was undertaken to determine whether the seam weld quality of modern ERW/HFI pipe has been improved to justify more widespread use, particularly in critical locations, with resultant reductions in construction costs. The report describes the test protocol and results from six samples ranging from X60 through X70 pipe provided by PRCI member companies. Variations in weld zone properties in one of the samples are reviewed and attributed in some detail.
L51912 Corrosion-CP Monitoring of Locations Remote from a Test Station
Authors: Fourie  , Tullmin
Published: August 2023

It is accepted that many situations exist on pipelines where a significant length of the pipeline (typically 2000 ft to 5 miles) is either totally inaccessible or access is so difficult or expensive that monitoring is not done at the required frequency. The need for finding a technique to allow the corrosion engineer to monitor CP levels of inaccessible locations from an accessible remote location has therefore been identified.

A study to investigate all possible techniques available to achieve the above objective and to analyze typical scenarios requiring this approach has therefore been undertaken. Numerous techniques varying from pipe-to-soil type measurements, above ground current attenuation measurements, direct measurement of pipeline current, and measurement of the AC impedance response of the inaccessible section of pipeline were identified. In addition, some novel remote monitoring methods applicable to hostile inaccessible locations were identified. Analysis of these techniques in relation to the problem lead to the development of an algorithm to facilitate the choice of possible techniques under specific conditions.
L51497 Investigating the Weldability of Quenched and Tempered Pipeline Materials
Authors: Dorling
Published: August 2023

This program studied the effects of girth welding on the mechanical properties of four quenched and tempered pipeline materials. The study revealed the presence of low-toughness regions in the heat-affected zone of shielded metal arc welds in heavy-wall pipe and fitting materials rated for above-ground service. High-strength, microalloyed steels produced by other processes are also known to be susceptible to similar localized toughness degradation. Because the significance of these regions, with regards to service performance, is not fully understood, further research involving full-scale fracture testing is recommended.