Experimental Study of Elevated Temperature Composite Repair Materials to Guide Integrity Decisions

2016 ◽  
Author(s):  
Colton Sheets ◽  
Robert Rettew ◽  
Chris Alexander ◽  
Denis Baranov ◽  
Patrick Harrell
Keyword(s):  
Experimental Study ◽  
Elevated Temperature ◽  
Composite Materials ◽  
Elevated Temperatures ◽  
Test Group ◽  
Small Scale ◽  
Composite Repair ◽  
Composite Systems ◽  
Repair Systems

Over the past two decades, a significant amount of research has been conducted on the use of composite materials for the repair and reinforcement of pipelines. This has led to vast improvements in the quality of composite systems used for pipeline repair and has increased the range of applications for which they are viable solutions (including corrosion and mechanical damage). By using composite repair systems, pipeline operators are often able to restore the structural integrity of damaged pipelines to levels equal to or even in excess of the original undamaged pipe. Although this research has led to substantial advancements in the quality of these repair systems, there are still specific applications where questions remain regarding the strength, durability, and effectiveness of composite repair systems, especially in elevated temperature, harsh environment conditions. This program initially involved composite repair systems from six manufacturers. The test group included both carbon and E-glass based systems. Performance based qualifications were used to reduce the size of the test group from the initial six systems down to three. The experimental study consisted of small-scale testing efforts that ranged from tensile tests performed over a range of temperatures to 10,000-hour material coupon tests at elevated temperatures. The elevated temperatures used for testing were intentionally selected by the operator to reflect the 248 °F design temperature of the target pipeline. Using small-scale qualification testing outlined in ASME PCC-2 – Repair of Pressure Equipment and Piping standard (Article 4.1, Nonmetallic Composite Repair Systems: High-Risk Applications) as a foundation, the test program described in this paper was able to demonstrate that, when properly designed, and installed, some composite materials are able to maintain their effectiveness at high temperatures. This study combined short-term and long-term testing of composite systems and demonstrated the advantages of a 10,000 hour test when aging properties are unknown. Finally, the study showed that, although high-temperature reinforcement using composite repair systems is feasible and commercially available, this capability is not standard practice across the composite repair industry. Proper analysis and verification using experimental methods, including full scale testing should be conducted prior to installation of a composite repair system in these types of harsh conditions.

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.

Full-Scale Elevated Temperature Testing of Composite Repairs in Bending and Compression

2016 ◽  
Author(s):  
Colton Sheets ◽  
Robert Rettew ◽  
Chris Alexander ◽  
Tanya Axenova
Keyword(s):  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Water Immersion ◽  
Full Scale ◽  
Composite Repair ◽  
In Situ Conditions ◽  
Depth Analysis ◽  
Repair Systems ◽  
Full Scale Testing

The increasing use of composite repair systems in critical and complex applications has brought greater scrutiny to their design and performance. This has been especially true in high-temperature, immersed environment applications where ambient temperature test results with industry standard de-rating factors are all that is available for design. Since this approach does not always adequately capture environmental effects or the performance of composite systems at elevated temperatures, it is beneficial to perform full-scale testing which accurately replicates the in-situ application. In order to accomplish this, a full-scale testing program was developed that subjected multiple composite repair systems to internal and external loads at temperatures up to 120 °C with and without water immersion. This program involved the reinforcement of 12.75-inch × 0.375-inch pipe samples that had simulated corrosion defects. Full-scale load and pressure testing was conducted to simulate the long-term performance of the composite repair systems in the environmental conditions of the application. A strain based performance threshold of 0.4% strain at 120 °C and 100% SMYS was used to develop a competitive program that ranked the participating systems and reduced the number of acceptable repairs from six down to three. This approach increased the efficiency of the full-scale testing and allowed for more in-depth analysis of the top-performing systems. The results of the full-scale testing of six composite repair systems at elevated temperature allowed for a quantitative measure of their effectiveness under in-situ conditions. Several of the systems were shown to provide inadequate reinforcement under these conditions; however, it was also observed that appropriately designed and installed systems are capable of meeting the intense demands of elevated temperature, harsh-service conditions.

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.

Fatigue Behavior of Metallic Pipes With Through-Wall Corrosion Damage Repaired With Bonded Metallic Patches

2020 ◽  
Author(s):  
Camila de Luca ◽  
Julia Sathler ◽  
João Fellipe Souza ◽  
Heraldo Mattos
Keyword(s):  
Experimental Study ◽  
Fatigue Behavior ◽  
Corrosion Damage ◽  
Composite Repair ◽  
Pressure Transients ◽  
Early Failures ◽  
Repair Systems ◽  
Inelastic Strains ◽  
Successful Repair

Abstract Composite repair systems have been gaining each time more space in industry, especially when it comes to repairing through-wall defects in pipes. They are simpler to apply, have no costly downtime and provide lower risks to the environment when compared to metallic repairs. ASME PCC-2 and ISO 24817 standards are responsible for defining the parameters necessary to a successful repair, however neither of them addresses a very common practice in such repairs, which is the addition of a bonded metallic patch over the defect. Several companies are adepts of such practice and it has already been proven that is actually the metallic patch and not the composite sleeve itself that sustains most of the load applied on the repair, and for that reason it becomes necessary to conduct further studies regarding the behavior of the patch alone. One important issue is to understand why the strength of similar repairs due to operation errors with very similar amplitude of pressure transients seems to vary randomly, with unexplained early failures. The present paper is concerned with an experimental study about how pressure variations can generate cyclic inelastic strains in the pipe, which can weaken the adhesion between pipe and patch, leading the repair to fail prematurely.

Quality of life of residents with dementia in traditional versus small-scale long-term care settings: A quasi-experimental study

2012 ◽  
Vol 49 (8) ◽  
pp. 931-940 ◽  
Author(s):  
Alida H.P.M. de Rooij ◽  
Katrien G. Luijkx ◽  
Juliette Schaafsma ◽  
Anja G. Declercq ◽  
Peggy M.J. Emmerink ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Experimental Study ◽  
Long Term Care ◽  
Small Scale ◽  
Term Care ◽  
Quasi Experimental

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.

Development and Evaluation of a Steel-Composite Hybrid Composite Repair System

2012 ◽  
Author(s):  
Chris Alexander ◽  
Carl Brooks
Keyword(s):  
Composite Materials ◽  
Hybrid System ◽  
Hybrid Composite ◽  
Carbon Materials ◽  
Repair System ◽  
Glass Composite ◽  
Composite Repair ◽  
Cyclic Pressure ◽  
Steel Composite ◽  
Repair Systems

Composite materials are widely recognized as a resource for repairing damaged pipelines. The fibers in conventional composite repair systems typically incorporate E-glass and carbon materials. To provide greater levels of reinforcement a system was developed that incorporates steel half shells and an E-glass composite repair system. In comparison with other competing composite technologies, the hybrid system has a significant capacity to reduce strain in corroded pipeline to a level that has not been seen previously. Specifically, the hybrid system was used to reinforce a pipe sample having 75% corrosion subjected to cyclic pressure at 36% SMYS. This sample cycled 767,816 times before a leak failure developed. Furthermore, recent testing has demonstrated that the hybrid system actually places the pipeline in compression during installation. This paper will provide results on a series of specifically-designed tests to evaluate the performance of the hybrid system and the implications in relation to the service of actual pipelines.

AN EXPERIMENTAL STUDY OF MICRO-VOID CREATION BY IMPURITY IN COMPOSITE MATERIALS DURING VARTM PROCESS

2011 ◽  
Vol 25 (31) ◽  
pp. 4204-4207 ◽  
Author(s):  
Yun-Hae Kim ◽  
Kyung-Man Moon ◽  
Byeong-Woo Lee ◽  
Joon-Young Kim ◽  
Dong-Hun Yang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Composite Materials ◽  
Environmental Control ◽  
Resin Transfer Molding ◽  
Transfer Molding ◽  
Large Structures ◽  
Vartm Process

The effects of impurities on the generation of voids in composites fabricated by vacuum-assisted resin transfer molding was investigated to help reduce mechanical weakening in large structures. Impurities were intentionally inserted into laminates, which were then observed optically. Internal voids were generated in specimens with impurities of 2 – 3mm thickness. The voids grew as the impurities' thicknesses increased to 4 – 5 mm. The voids' diameters were proportional to the thickness of the impurity. Void generation was shown to depend on the thickness of impurities. Environmental control during vacuum-assisted resin transfer molding was shown to be important for ensuring the quality of the resulting composites.

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.

Assessing the Use of Composite Materials in Reinforcing Offshore Risers and Pipelines

2011 ◽  
Author(s):  
Chris Alexander
Keyword(s):  
Composite Materials ◽  
Internal Pressure ◽  
State Of The Art ◽  
Management Service ◽  
Offshore Pipelines ◽  
Composite Repair ◽  
Composite Systems ◽  
Need To Evaluate ◽  
Bending Loads ◽  
Offshore Risers

Composite systems are a generally-accepted method for repairing corroded and mechanically-damaged onshore pipelines. The pipeline industry has arrived at this point after more than 15 years of research and investigation. Because the primary method of loading for onshore pipelines is in the circumferential direction due to internal pressure, most composite systems have been designed and developed to provide hoop strength reinforcement. On the other hand, offshore pipes (especially risers), unlike onshore pipelines, can experience significant tension and bending loads. As a result, there is a need to evaluate the current state of the art in terms of assessing the use of composite materials in repairing offshore pipelines and risers. The paper presents findings from a joint industry effort involving the Minerals Management Service, the Offshore Technology Research Center at Texas A&M University, Stress Engineering Services, Inc., and several composite repair manufacturers was undertaken to assess the state of the art using full-scale testing methods. Loads typical for offshore risers were used in the test program that integrated internal pressure, tension, and bending loads. This program is the first of its kind and likely to contribute significantly to the future of offshore riser repairs. It is anticipated that the findings of this program will foster future investigations involving operators by integrating their insights regarding the need for composite repair based on emerging technology.

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