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.

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 Composite Systems Used to Repair Transmission Pipelines

2006 ◽  
Author(s):  
Chris Alexander ◽  
Bob Francini
Keyword(s):  
Composite Materials ◽  
Third Party ◽  
Composite Repair ◽  
Critical Elements ◽  
Research Organizations ◽  
Repair Systems ◽  
Long Term Performance ◽  
Term Performance ◽  
Transmission Pipelines

For the past decade there has been relatively wide acceptance in using composite materials to repair damaged gas and liquid transmission pipelines. There have been numerous independent research programs performed by pipeline companies, research organizations, and manufacturers that have contributed to the acceptance of composites as a legitimate repair material. Additionally, insights have been gained by both pipeline operators and composite repair manufacturers during field installations. ASME has also responded by adding sections to both the ASME B31.4 and B31.8 pipeline codes, as well as currently developing a repair standard for non-metallic composite repair systems by the Post Construction Committee. Stress Engineering Services, Inc. and Kiefner & Associates, Inc. have been integrally involved in assessing the repair of pipeline systems, with the former having been involved in performing full-scale testing and analysis on most of the major U.S.-based composite repair systems. The purpose of this paper is to provide for the pipeline industry a third-party evaluation of composite repair systems and information that is needed to properly evaluate how composite materials should be used to repair high pressure pipelines. The contents of the paper will include discussions on what critical elements should be evaluated for each composite system, items of caution and concern, and the importance of evaluation to ensure safe long-term performance.

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.

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.

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.

Development of Industry Standards for Composite Repair Systems

2010 ◽  
Author(s):  
Chris Alexander ◽  
Franz Worth
Keyword(s):  
Repair System ◽  
Design Codes ◽  
Composite Repair ◽  
The Past ◽  
Design Variables ◽  
Industry Standards ◽  
Piping Systems ◽  
Current Design ◽  
Reinforced Steel ◽  
Repair Systems

A significant amount of work has transpired over the past several years in generating consensus-based standards that include ASME PCC-2 and ISO 24817 for developing composite repair systems. The intent in developing these standards has been to provide industry with guidelines for designing composite repair systems to ensure that damaged pipelines and piping systems are safely and properly reinforced. With the numerous composite repair systems currently available to pipeline operators, the importance of evaluating the capabilities of each system cannot be overstated. The fundamental design variables available to manufacturers are stiffness, strength, and thickness of the composite. A properly-designed repair system ensures that strains in the reinforced steel and reinforcing composite material do not reach unacceptable levels. This paper provides a basic overview of the design philosophy embedded into the current design codes, as well as presenting results associated with several specific studies that were conducted to evaluate composite repair performance.

Using Industry Standards for Designing Composite Repair Systems for Corroded Process Piping

2010 ◽  
Author(s):  
Chris Alexander ◽  
Franz Worth
Keyword(s):  
Repair System ◽  
Design Codes ◽  
Composite Repair ◽  
The Past ◽  
Design Variables ◽  
Industry Standards ◽  
Process Piping ◽  
Current Design ◽  
Reinforced Steel ◽  
Repair Systems

A significant amount of work has transpired over the past several years in generating consensus-based standards that include ASME PCC-2 and ISO 24817 for developing composite repair systems. The intent in developing these standards has been to provide industry with guidelines for designing composite repair systems to ensure that damaged piping and pipelines are safely and properly reinforced. With the numerous composite repair systems currently available to operators, the importance of evaluating the capabilities of each system cannot be overstated. The fundamental design variables available to manufacturers are stiffness, strength, and thickness of the composite. A properly-designed repair system ensures that strains in the reinforced steel and reinforcing composite material do not reach unacceptable levels. This paper provides a basic overview of the design philosophy embedded into the current design codes, as well as presenting results associated with several specific studies that were conducted to evaluate composite repair performance.

Repair of High Pressure Pipe Fittings Using Composite Materials

2010 ◽  
Author(s):  
Julian Bedoya ◽  
Chris Alexander ◽  
Tommy Precht
Keyword(s):  
Composite Materials ◽  
Structural Integrity ◽  
Burst Pressure ◽  
Metal Loss ◽  
Repair System ◽  
Composite Repair ◽  
Main Challenge ◽  
Repair Systems ◽  
Pipe Fittings ◽  
Original Metal

Pipelines and piping frequently suffer from metal loss that threatens their integrity and serviceability. Multiple repair options exist for straight sections of pipe; however, repair options for pipe fittings such as elbows and tees are typically limited to composite repair systems, or section replacement. The latter method can be costly as it often requires at least a partial shut down of the pipeline while the section is replaced. A composite repair system however, can be performed in place during operations at a greatly reduced cost. The main challenge with the composite repair system is the required demonstrated ability to restore integrity and serviceability to the same level as the original metal system. Over the past 10 years, Stress Engineering Services, Inc. has been greatly involved in evaluating the ability of many composite repair systems to restore the original pipeline structural integrity by testing methods and analysis methods. The current paper investigated the ability of the Armor Plate Pipe Wrap (APPW) system to restore the burst pressure of tee and elbow pipe fittings with 60% metal loss to that of a nominal thickness system. In this program four full scale burst tests were conducted: on 12-inch nominal pipe size (NPS) Y52 tee and elbow pipe fittings. All four fittings had 60% metal loss; two were repaired with APPW, and the other two were not repaired. Prior to burst testing, elastic plastic finite element analyses (FEA) were performed to adequately size the repair thickness. The results of the FEA calculations predicted the restoration of the burst pressures of the repaired fittings up to a 1.6% agreement with the actual burst pressure results. Furthermore, the burst pressure of the 60% metal loss tee was increased from 3,059 psi (unrepaired) to 4,617 psi, or a 51% improvement. The burst pressure of the 60% metal loss elbow was increased from 2,610 psi to 4,625 psi, or a 77% improvement. Both the analysis and testing results demonstrated that composite materials can restore the pressure integrity of corroded tee and elbow pipe fittings.

Advanced Insights on Composite Repairs

2012 ◽  
Author(s):  
Chris Alexander ◽  
Jim Souza
Keyword(s):  
Composite Materials ◽  
Test Sample ◽  
Repair System ◽  
Strain Gages ◽  
Composite Repair ◽  
Pressure Cycling ◽  
Repair Systems ◽  
Long Term Performance ◽  
Term Performance

In response to inquiries from pipeline operators regarding the long-term performance of composite materials, manufacturers have performed additional tests to evaluate the performance of their composite repair systems. Insights were gained through these additional tests that demonstrated the long-term worthiness of the composite system. Of particular importance were two types of tests. The first involved the application of strain gages between layers of the composite repair system that was used to reinforce a corroded pipe test sample. As the sample was pressurized the strain gages permitted a comparison between the measured values and design stresses per the ASME PCC-2 design code. The second series of tests involved pressure cycling a 75% corroded sample to failure. In addition to the inter-layer strain measurements, the pressure cycling provides an important insight regarding the long-term performance of the composite repair. This paper addresses how the ASME PCC-2 Code, along with additional well-designed tests, can be used to design a composite repair system to ensure that it adequately reinforces a given defect. As composite materials are being used to repair pipeline anomalies beyond the corrosion-only defects, it is essential that pipeline operators utilize a systematic approach for ensuring the long-term performance of composite repair systems.

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