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.

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.

Strain-Based Design Methods for Composite Repair Systems

2008 ◽  
Author(s):  
Chris Alexander
Keyword(s):  
Finite Element ◽  
Composite Materials ◽  
Design Method ◽  
Design Methods ◽  
Strain Gages ◽  
Composite Repair ◽  
Reinforced Steel ◽  
Long Term Performance ◽  
Term Performance

Composite materials are commonly used to repair corroded and mechanically-damaged pipelines. Most of these repairs are made on straight sections of pipe. However, from time to time repairs on complex geometries such as elbows, tees, and field bends are required. Conventional design methods for determining the amount of required composite materials are not conducive for these types of repairs. Over the past several years, the author has developed a methodology for assessing the level of reinforcement provided by composite materials to damaged pipelines using finite element methods. Instead of stress as the design basis metric, the method employs a strain-based design criteria that is ideally-suited for evaluating the level of reinforcement provided to non-standard pipe geometries. The finite element work has been validated using experimental methods that employed strain gages placed beneath the composite repair to quantify the level of reinforcement provided by the repair. This paper provides a detailed description of the strain-based design method along with appropriate design margins for both the reinforced steel and long-term performance of the composite materials.

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.

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.

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.

Fine Particle Mass Monitoring with Low-Cost Sensors: Corrections and Long-Term Performance Evaluation

2019 ◽  
Author(s):  
Carl Malings ◽  
Rebecca Tanzer ◽  
Aliaksei Hauryliuk ◽  
Provat K. Saha ◽  
Allen L. Robinson ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Fine Particle ◽  
Low Cost ◽  
Particle Mass ◽  
Long Term Performance ◽  
Term Performance

Long-term performance of the Hancock bioprosthetic conduit for aortic root replacement

2008 ◽  
Vol 56 (S 1) ◽  
Author(s):  
CC Badiu ◽  
W Eichinger ◽  
D Ruzicka ◽  
I Hettich ◽  
S Bleiziffer ◽  
...  
Keyword(s):  
Aortic Root ◽  
Aortic Root Replacement ◽  
Long Term Performance ◽  
Term Performance
Sign in / Sign up

Export Citation Format

Share Document