An Operator’s Perspective in Evaluating Composite Repairs

2010 ◽  
Author(s):  
Satish Kulkarni ◽  
Chris Alexander
Keyword(s):  
Composite Materials ◽  
Performance Tests ◽  
Composite Repair ◽  
Research Programs ◽  
Recent Introduction ◽  
Industry Standards ◽  
Repair Materials ◽  
Girth Welds ◽  
Composite Repairs

For more than a decade composite materials have been used by pipeline operators to repair damaged pipelines. To validate the performance of composite repair materials, numerous research programs have been conducted. The recent introduction of standards such as ASME PCC-2 and ISO 24817 have provided industry with guidance in using composite materials concerning factors such as the minimum required repair thickness, recommended performance tests, and qualification guidance. Up until now, operators have developed individual requirements for how composite materials can be used and under what circumstances their use is deemed acceptable. To compliment these internal guidance standards, several operators have elected to conduct independent investigations to evaluate the benefits derived in using composite materials for reinforcing specific anomalies such as gouges, dents, girth welds, and wrinkle bends. This paper provides insights that can be used by operators in evaluating the use of composite materials in repairing damaged pipelines with an emphasis on incorporating the current industry standards.

Composite Repair Performance at Elevated Temperatures

2014 ◽  
Author(s):  
Chris Alexander ◽  
Jim Souza ◽  
Casey Whalen
Keyword(s):  
Composite Materials ◽  
Elevated Temperatures ◽  
Critical Role ◽  
Ambient Conditions ◽  
Composite Repair ◽  
Repair Materials ◽  
Performance Curves ◽  
Repair Systems ◽  
Composite Repairs

For the better part of the past 20 years composite materials have been used to repair damaged piping and pressurized components in plants, refineries, and pipelines. The use of composite materials has been accompanied by comprehensive research programs focused on the development and assessment of using composite technology for restoring integrity to damaged piping and pressurized components. Of particular interest are composite repair standards such as ISO 24817 and ASME PCC-2 that provide technical guidance in how to properly design composite repair systems. The vast body of research completed to date has involved assessments at ambient conditions; however, at the present time there is significant interest in evaluating the performance of composite repair materials at elevated temperatures. This paper is focused on the topic of high temperature composite repairs and addresses the critical role of utilizing temperature-based mechanical properties to establish a composite repair design. The backbone of this effort is the development of composite performance curves that correlate change in strength as a function of temperature. A discussion on supporting full-scale pressure test results are included, along with guidance for users in how to properly design composite repair systems for applications at elevated temperatures.

Repair of Dents Subjected to Cyclic Pressure Service Using Composite Materials

2010 ◽  
Author(s):  
Chris Alexander ◽  
Julian Bedoya
Keyword(s):  
Composite Materials ◽  
Extensive Study ◽  
Life Extension ◽  
Composite Repair ◽  
The Past ◽  
Extensive Evaluation ◽  
Research Organizations ◽  
Repair Systems ◽  
Primary Focus ◽  
Girth Welds

For the better part of the past 15 years composite materials have been used to repair corrosion in high pressure gas and liquid transmission pipelines. This method of repair is widely accepted throughout the pipeline industry because of the extensive evaluation efforts performed by composite repair manufacturers, operators, and research organizations. Pipeline damage comes in different forms, one of which involves dents that include plain dents, dents in girth welds and dents in seam welds. An extensive study has been performed over the past several years involving multiple composite manufacturers who installed their repair systems on the above mentioned dent types. The primary focus of the current study was to evaluate the level of reinforcement provided by composite materials in repairing dented pipelines. The test samples were pressure cycled to failure to determine the level of life extension provided by the composite materials relative to a set of unrepaired test samples. Several of the repaired dents in the study did not fail even after 250,000 pressure cycles were applied at a range of 72% SMYS. The results of this study clearly demonstrate the significant potential that composite repair systems have, when properly designed and installed, to restore the integrity of damaged pipelines to ensure long-term service.

scholarly journals Precise Design and Analysis of Wet Layup Composite Repairs

1999 ◽  
Author(s):  
Greg Kress
Keyword(s):  
Composite Structures ◽  
Heat Sinks ◽  
Underlying Structure ◽  
Composite Repair ◽  
Processing Equipment ◽  
Analysis Techniques ◽  
Repair Materials ◽  
Physical Limitations ◽  
Composite Repairs

Abstract The increasing size and cost of composite structures combined with the increased loading requirements placed on such components has heightened the need for performing durable and thoroughly analyzed composite repairs. Precise applications of composite repairs possess many difficulties from both a maintenance and engineering standpoint. The composite repair engineer is often limited by the repair materials and processing equipment that are available, the data to define the loads placed on the structure, and physical limitations such as the inability to remove a panel from the aircraft, heat sinks, and underlying structure. This presentation describes the repair configuration, materials and analysis techniques for performing the precise design and analysis of wet layup composite repairs.”

Developing Stress Intensification Factors for Composite Repair Systems Used to Repair Damaged Pipe

2010 ◽  
Author(s):  
Chris Alexander
Keyword(s):  
Composite Materials ◽  
Extensive Study ◽  
Life Extension ◽  
Composite Repair ◽  
The Past ◽  
Extensive Evaluation ◽  
Research Organizations ◽  
Piping Systems ◽  
Repair Systems ◽  
Girth Welds

For the better part of the past 15 years composite materials have been used to repair corrosion in high pressure gas and liquid transmission pipelines. This method of repair is widely accepted throughout the pipeline industry because of the extensive evaluation efforts performed by composite repair manufacturers, operators, and research organizations. Pipeline damage comes in different forms, one of which involves dents that include plain dents, dents in girth welds and seam welds. An extensive study has been performed over the past several years involving multiple composite manufacturers that installed their repair systems on the above mentioned dent types. The test samples were pressure cycled to failure to determine the level of life extension provided by the composite materials over a set of unrepaired test samples. Several of the repaired dents in the study did not fail even after 250,000 pressure cycles had been applied at a range of 72% SMYS. The primary purpose of this paper is to present details on how Stress Intensification Factors were derived using the empirically-generated data. The results of this study clearly demonstrate the significant potential that composite repair systems have, when properly designed and installed, to restore the integrity of damaged pipelines and piping systems to ensure long-term service.

State-of-the-Art Assessment of Today’s Composite Repair Technologies

2018 ◽  
Author(s):  
Chris Alexander ◽  
Richard Kania
Keyword(s):  
State Of The Art ◽  
Full Scale ◽  
Regulatory Agencies ◽  
Independent Research ◽  
Composite Repair ◽  
Sponsored Programs ◽  
Multiple Case ◽  
Multiple Case Studies ◽  
Conducting Research ◽  
Girth Welds

For almost 30 years composite repair technologies have been used to reinforce high pressure gas and liquid pipeline transmission systems around the world. The backbone of this research has been full-scale testing, aimed at evaluating the reinforcement of anomalies including, corrosion, dents, vintage girth welds, and wrinkle bends. Also included have been the assessment of reinforced pipe geometries including welded branch connections, elbows, and tees. Organizations sponsoring these research efforts have included the Pipeline Research Council International, regulatory agencies, pipeline operators, and composite repair manufacturers. Many of these efforts have involved Joint Industry Programs; to date more than 15 different industry-sponsored programs and independent research efforts have been conducted involving more than 1,000 full-scale destructive tests. The aim of this paper is to provide for the pipeline industry an updated perspective on research associated with composite repair technologies. Because of the continuous advance in both composite technology and research programs to evaluate their effectiveness, it is essential that updated information be provided to industry to minimize the likelihood for conducting research efforts that have already been addressed. To provide readers with useful information, the authors will include multiple case studies that include the reinforcement of dents, wrinkle bends, welded branch connections, and planar defects.

Advanced Techniques for Establishing Long-Term Performance of Composite Repair Systems

2014 ◽  
Author(s):  
Chris Alexander
Keyword(s):  
The United States ◽  
Operating Conditions ◽  
Repair System ◽  
Composite Repair ◽  
Design Life ◽  
Repair Systems ◽  
Long Term Performance ◽  
Term Performance ◽  
Composite Repairs

Although composite materials are used to repair and reinforce a variety of anomalies in high pressure transmission gas and liquid pipelines, there continues to be widespread debate regarding what constitutes a long-term composite repair. The United States regulations require that composite repairs must be able to permanently restore the serviceability of the repaired pipeline, while in contrast the Canadian regulations take a more prescriptive approach by integrating the ASME PCC-2 and ISO 24817 composite repair standards along with a requirement for establishing a 50-year design life. In this paper the author provides a framework for what should be considered in qualifying a composite repair system for long-term performance by focusing on the critical technical aspects associated with a sound composite repair. The presentation includes a discussion on establishing an appropriate composite design stress using the existing standards, using full-scale testing to ensure that stresses in the repair do not exceed the designated composite design stresses, and guidance for operators in how to properly integrate their pipeline operating conditions to establish a design life. By implementing the recommendations presented in this paper, operators will be equipped with a resource for objectively evaluating the composite repair systems used to repair their pipeline systems.

Long-Term Evaluation of the Bonding Strength of Composite Repairs

2012 ◽  
Author(s):  
Khalid Farrag ◽  
Kevin Stutenberg
Keyword(s):  
Shear Strength ◽  
Elevated Temperatures ◽  
Water Solution ◽  
Effect Of Temperature ◽  
Shear Tests ◽  
Composite Repair ◽  
Testing Program ◽  
Repair Systems ◽  
Composite Repairs

The long-term performance of composite repair systems depends on their structural integrity and interaction with the carrier pipe. The adhesives used in the composites are critical components that not only bond the repair to the pipe, but also bond the individual layers of the repair to one another. The durability of the inter-laminate adhesive bond is required to ensure adequate load transfer between the pipe and the composite layers over the predicted lifetime of the repair. A testing program was performed to evaluate the shear strength of the adhesives used in composite repairs. The testing program evaluated the performance of seven commercially-available composite repair systems and it consisted of short-term and long-term shear tests on the adhesives and cathodic disbondment tests on the repair systems. The long-term shear tests were performed for 10,000 hours on samples submerged in a water solution with pH value of 9 and at various loading levels at temperatures of 70°F, 105°F and 140°F. The results of the long-term tests at elevated temperatures were extrapolated to predict the shear strengths at longer durations. The 20-year shear strengths of the composites were estimated using: (a) direct extrapolation of the best-fit curves and (b) the application of the rate process procedure. The results demonstrated the significant effect of temperature on the bond strength of the composites and provided a comparative analysis to evaluate the long-term shear strength and cathodic disbondment of the composite repair systems.

The Role of Composite Repair Technology in Rehabilitating Piping and Pipelines

2014 ◽  
Author(s):  
Chris Alexander
Keyword(s):  
Quality Control ◽  
High Pressure ◽  
Composite Materials ◽  
Research Council ◽  
Mechanical Damage ◽  
Control Measures ◽  
Composite Repair ◽  
Repair Technology

Composite materials have been used to repair high pressure pipelines and piping for the better part of 20 years. The initial aim of composite repair technology was focused on reinforcing corrosion. However, composite materials are now used to reinforce a wide array of anomalies and features including dents, mechanical damage, vintage girth and seam welds, wrinkle bends, elbows, tees, branch connections, and even cracks. In this paper the author provides an industry overview including results and insights from multiple research programs sponsored by composite repair manufacturers, pipeline operators, and the Pipeline Research Council International, Inc. Discussions will also be included regarding the important role that the ASME PCC-2 and ISO 24817 composite repair standards have in ensuring that quality control measures are in place. The ongoing focus of these efforts has been to demonstrate to industry the capabilities that composite repair systems have to provide long-term solutions for reinforcing damaged equipment.

Long-Term Duration of Composite Repair Systems for Pipeline Defects

2021 ◽  
Vol 1035 ◽  
pp. 870-877
Author(s):  
Lian Xun Ming ◽  
Deng Zun Yao ◽  
Bin Chen ◽  
Zhen Heng Teng ◽  
Lin Wang
Keyword(s):  
Composite Materials ◽  
Water Immersion ◽  
Prediction Equation ◽  
Field Application ◽  
Composite Repair ◽  
Micro Cracks ◽  
Aging Properties ◽  
Repair Systems ◽  
Hydrolysis Of

Composite repair systems of buried pipeline will be affected by moisture and other factors due to anti-corrosion and construction problems. These environmental factors will reduce the service life of the composite system. In this paper, the performance of composite and interface between composite and steel under the action of water were studied. It was found that the formation of micro-cracks on the surface of composite materials and the hydrolysis of epoxy resin were the important reasons for the Performance degradation. Moreover, the aging properties of composite materials and their interfaces under water immersion were analyzed by residual strength theory, and the life prediction equation of composite materials and interfaces were obtained, which can be useful to the field application of composite repair systems.

Performance and Integrity Issues for Composite Reinforced Steel Pipelines With Cathodic Protection

2010 ◽  
Author(s):  
Robert A. Denzine ◽  
Davion M. Hill
Keyword(s):  
Cathodic Protection ◽  
Composite System ◽  
Metal Composite ◽  
Composite Repair ◽  
Reinforced Steel ◽  
Point Bend ◽  
Soil Corrosivity ◽  
Corrosive Environments ◽  
Composite Repairs

Composites have seen increased usage for repair of pipelines. The performance of the entire metal-composite system has not been extensively addressed with regard to corrosion of the substrate and adhesion loss when the conditions are wet and the substrate is cathodically protected. In this work we have investigated the influence of corrosive environments on the performance of composite repair systems for pipelines. Earlier in this work we used FEA models to evaluate a composite patch for pipelines and the present research includes the experimental results for both patch and full-wrap composite repairs in simulated and field environments. The effect of impacts, cathodic protection, long term immersion, and soil corrosivity have been investigated by monitoring variables related to potential and conductivity of the electrolyte. We have also tested mechanical properties via four point bend on specimens intentionally exposed to ASTM cathodic disbondment tests. We have also evaluated the performance of these repairs in a modified ASTM G8 cathodic disbondment test with the addition of high pressure cyclic loading. By monitoring these variables, loss of adhesion and integrity in the composite-metal system is addressed.

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