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.

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.

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.

New Method for In-Trench Pipeline Support

2012 ◽  
Author(s):  
Geoff W. Connors
Keyword(s):  
Cathodic Protection ◽  
Welding Process ◽  
High Strength ◽  
Test Water ◽  
Poly Type ◽  
Additional Protection ◽  
Injection Molded ◽  
Heavy Loads ◽  
Sand Piles

Protection of the pipe during and after pipeline construction is of paramount importance for safety and pipeline integrity. Areas of rock and stone are often encountered during construction of new pipelines. Even with modern pipeline coatings, additional protection for the pipe is necessary where rock or stone exposure is significant. Historically, additional pipe protection used in these types of situations is achieved through adding either a significant layer of sand or select backfill above and below the pipeline (sand padding) and/or by attaching a high-impact resistant, poly-type rock shield around the pipeline during the pipeline installation process. To accommodate sand padding, some form of intermittent support of the pipeline is generally required to elevate the pipeline off the trench bottom. Similar intermittent support is also recommended practice when using poly-type rock shields to keep the pipeline from fully resting on trench rocks. Current methods of in-trench support involve sand piles, sand bags, spray foam and individually formed foam pillows — each with drawbacks: i) Sand Piles are difficult to install and often oval or dent the pipe when improperly placed. ii) Sand bags require hand placement for proper support. In open trenches, this can be time consuming and unsafe. Improper placement can cause the pipe to oval or dent. iii) Spray-in foam is considered to be an obstruction of cathodic protection currents. Newly constructed pipelines full of hydrostatic test water and one metre cover can cause foam to compress excessively. iv) Foam pillows are light and easily placed — but can float out of position and compress or crack under heavy loads. As with all foam, cathodic shielding is always a concern. A new, engineered method of in-trench pipeline support is now available — the Structured Pipeline Pillow (SPP). SPP’s are injection molded and made from high strength, environmentally inert polypropylene or polyethylene resins. Designed to support any size pipeline, SPP’s are most effective with larger diameter, heavier pipelines. One SPP is engineered to carry a single 40′ joint of heavy wall pipeline filled with hydrostatic test water. Compared with current methods, SPP’s: i) Stack tightly for transport. ii) Are light enough for installation from outside the trench and resist floatation when ground water is present. iii) Help ensure the pipeline is centered in the trench during the pipeline installation. iv) Maintain long-term pipe clearance above rocky trench bottoms. v) Ovality and denting concerns are reduced. vi) Allow cathodic protection an easy path to the pipeline. vii) Will never biodegrade. In their extended stacking mode, SPP’s tested well as an effective alternative to wooden skids for many situations such as pipe stockpiling; stringing along the rights-of-way (ROW); and even for some low level skidding during the welding process.

scholarly journals Thickness and corrosion resistance optimization of Micro-ARC oxidation coating on Mg-Al-Li-Zn alloy using Taguchi approach

2020 ◽  
pp. 62-66
Author(s):  
Do Le Hung Toan, Shuo-Jen Lee Do
Keyword(s):  
Corrosion Resistance ◽  
Processing Time ◽  
Electrical Potential ◽  
Surface Protection ◽  
Alkaline Electrolytes ◽  
Micro Arc Oxidation ◽  
Corrosive Environments ◽  
Zn Alloy ◽  
Main Factor

Micro arc oxidation method has been developed in the field of surface protection of magnesium alloys and considered as a simple, highly effective, commercial and environmentally friendly method in industry. MAO coatings are fabricated on novel Mg-Al-Li-Zn alloy to improve the anti-corrosion performance of surface by using friendly alkaline electrolytes under a high electrical potential. The Taguchi method and optimal analysis are used to identify the effects of the three factors including current density, processing time and electrical frequency on coating’s characteristics. The results have shown that the main factor that affects coating thickness and corrosion resistance of coating is the processing time. The results obtained by optimal conditions are consistent with prediction values of Taguchi analysis. The thickness of the coating can help to improve the long-term corrosion protection of a MAO coating in corrosive environments.

Long-Term Photoelectrochemical Cathodic Protection by Co(OH)2-Modified TiO2on 304 Stainless Steel in Marine Environment

2018 ◽  
Vol 165 (4) ◽  
pp. H3154-H3163 ◽  
Author(s):  
Xuan Xie ◽  
Li Liu ◽  
Runze Chen ◽  
Gang Liu ◽  
Ying Li ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Marine Environment ◽  
Cathodic Protection ◽  
304 Stainless Steel

Long Term Performance of Fusion Bond Epoxy Coated Pipelines

2004 ◽  
Author(s):  
Robert Worthingham ◽  
Matt Cetiner
Keyword(s):  
Service Life ◽  
Cathodic Protection ◽  
Laboratory Tests ◽  
Large Diameter ◽  
Service Temperature ◽  
Line Pipe ◽  
Coating Type ◽  
Long Term Performance ◽  
Term Performance

TransCanada Pipelines has been using fusion bond epoxy (FBE) external coatings for large diameter line pipe since the early 1980’s. Overall, this coating type, when applied in accordance to the CSA Z245.20 standard provides excellent protection and long term service life. However, some reports from the field described the periodic occurrence of blistering and disbondment of the coating. In order to understand the magnitude and causes of these phenomena, an investigative program was initiated. Laboratory tests and a program of field examinations were carried out. Some of the variables considered were: age of the coating; service temperature; cathodic protection (CP) levels; and soil type. No evidence of a pipeline integrity threat associated with fusion bond epoxy deterioration was found at any of the locations examined. Observations and correlations of coating to exposure conditions will be presented.

The Methodology for the Selection of Technologies for the Removal of Microorganisms from ETICS

2016 ◽  
Vol 820 ◽  
pp. 200-205 ◽  
Author(s):  
Naďa Antošová ◽  
Katarína Minarovičová
Keyword(s):  
Decision Making ◽  
Thermal Insulation ◽  
Composite System ◽  
Biological Materials ◽  
Decision Making Process ◽  
Strategic Reasoning ◽  
Unicellular Organisms ◽  
Selection Of

The paper has the ambition to point out the validation of conceptual and a strategic reasoning in the design of solution of “green façade” with external thermal insulation composite system (ETICS). The text deals with selected information derived from long-term research on contamination of ETICS by biological materials (mostly unicellular organisms - algae). The paper concludes with a draft of decision-making process.

Influence mechanisms under different immersion methods and different strengths of concrete in corrosive environments, and verification via long‐term field test

2020 ◽  
Vol 21 (5) ◽  
pp. 1853-1864
Author(s):  
Rongling Zhang ◽  
Lina Ma ◽  
Peng Liu ◽  
Huisu Chen ◽  
Han Xing Zhu ◽  
...  
Keyword(s):  
Field Test ◽  
Corrosive Environments ◽  
Term Field

Mechanical Characterization of Atomic Layer Deposited (ALD) Alumina for Applications in Corrosive Environments

2009 ◽  
Vol 1222 ◽  
Author(s):  
Kuang-Shun Ou ◽  
I-Kuan Lin ◽  
Ping-Hsin Wu ◽  
Zhi-Kai Huang ◽  
Kuo-Shen Chen ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Interfacial Strength ◽  
Atomic Layer ◽  
Fatigue Loading ◽  
Damage Level ◽  
Alumina Films ◽  
Indentation Tests ◽  
Corrosive Environments

AbstractIn this work, thin ALD alumina films were fabricated for evaluating their capabilities as a barrier material for corrosive environments. The fracture toughness and the corrosion-resisting properties after fatigue cycle of these thin ALD alumina films have been characterized. Indentation tests indicate that the ALD alumina/Al structures could enhance both the yield strength of the metal and the effective fracture toughness of the coated ALD alumina films and this result could be useful for designing nanocomposite structures. However, the test results also indicate that the interfacial strength of the ALD/Al structures was prone to degrade under fatigue loading under corrosive environment. This could potentially be a problem for the long term reliability of related devices operated under a harsh environment. In addition, the strong correlation between indentation behavior and fatigue loading for the structure indicate that nanoindentation response could be possibly used to indicate the damage level of microstructures for future reliability evaluations.

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