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Narayanan Sambu Potty - One of the best experts on this subject based on the ideXlab platform.
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Optimization of Corrosion Allowance for Substructure Splash Zone Area
2013Co-Authors: Ong Shiou Ting, Fasri Mohd Fadzli, Narayanan Sambu PottyAbstract:Corrosion in Marine and Offshore Structures such as platform substructure is one of the issues to be considered during the design stage. The current Corrosion Allowance (CA) at the splash zone area for platform substructure in Malaysia is 12mm based on 30 years design life without considering the effect of coating performance and cathodic protection for the submerged splash zone area. This issue is crucial because many of the around 200 platforms and other marine structures in Malaysia are reaching their design life (DL) and a lower Corrosion Allowance would mean that they can continue to be used without strengthening the structures. The main objective of this study is to optimize the Corrosion Allowance for substructure splash zone areas for tropical climate recommended to new facilities in tropical climates (seawater surface temperature >20°C, e.g. Malaysia, Indonesia, Myanmar, Vietnam, etc). Herein, a study is conducted to reduce the requirement of Corrosion Allowance to 6mm on thickness for primary members of the jacket by gathering and correlating all the available codes and standard, analysis of actual field data, correlation between coating and cathodic protection effect towards splash zone. The implementation of the optimized Corrosion Allowance would benefit the owners of the marine structures such as oil and gas companies in terms of reduction in material and fabrication cost.
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Marine Corrosion of mild steel at Lumut, Perak
2012Co-Authors: Ong Shiou Ting, Narayanan Sambu Potty, Mohd Shahir LiewAbstract:The Corrosion rate of structural steels in the adverse marine and offshore environments affects the economic interest of offshore structures since the loss of steel may have significant impact on structural safety and performance. With more emphasis to maintain existing structures in service for longer time and hence to defer replacement costs, there is increasing interest in predicting Corrosion rate at a given location for a given period of exposure once the protection coating or cathodic protection is lost. The immersion depth, salinity, steel composition and water pollution will be taken into account. Various Corrosion Allowances are prescribed for structural members by different standards. There are no studies to determine the appropriate Corrosion Allowance for steel structures in marine environment in Malaysia. The objectives of the research are to determine the nature and rate of Corrosion in mm/year for steel structures in marine environment. It also tries to identify whether the Corrosion rate i...
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Study of marine structural Corrosion using Corrosion coupons in Lumut area
Malaysian journal of science, 2012Co-Authors: Narayanan Sambu Potty, Shiou Ting, Mohd Shahir LiewAbstract:The Corrosion rate in marine environments affects economic interest since the loss of steel in marine structures has impact on structural safety and performance. With emphasis to maintain existing structures in service, there is increasing interest in predicting Corrosion rate at a given location for a given period of exposure. Corrosion Allowances are prescribed for structural members by standards based on the Corrosion protection provided, expected rate of Corrosion and service life of structure. There are no studies to determine the appropriate Corrosion Allowance for marine steel structures in Malaysia. The research objectives are to determine the nature and rate of Corrosion and the effect of differences in the immersion depth and microalgae on the Corrosion rate. Two sets of Corrosion coupons of Type 3 Steel consisting of mild steel were immersed in seawater at Lumut in Malaysia. The Corrosion rate of the coupon is estimated based on the material weight loss with time. The Corrosion rate is controlled by oxidation in short term and bacterial activity in long term. Corrosion rate in the immersion zone is observed to be more than in the splash zone. The results are also compared with code prescriptions and discussed. (Keywords: rate of Corrosion, uniform Corrosion, pitting, Corrosion coupons, marine structures.)
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Prediction of Corrosion rates in marine and offshore structures
2011 National Postgraduate Conference, 2011Co-Authors: Ong Shiou Ting, Narayanan Sambu Potty, M. Shahir LiewAbstract:The Corrosion rate of structural steels in the hostile environments of the coastal, harbour or ocean zones effects the economic interest of offshore structures since both the loss of steel and pitting may have significant impacts on structural safety and performance. With the increasing emphasis to maintain existing structures in service for longer periods of time and hence to defer replacement costs, there is increasing interest in predicting Corrosion rate at a given location for a given period of exposure once the protection (coating or cathodic protection) is lost. A more accurate approach for engineering purposes is to develop predictive Corrosion Allowance based on Corrosion science, marine microbiology and good quality field data. The immersion depth, salinity, steel composition and water pollution will be taken into account to obtain useful data. The underlying approach is probabilistic because the input is not known precisely and may be natural phenomena such as weather conditions.
Dennis K. Williams - One of the best experts on this subject based on the ideXlab platform.
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ASME B31.3 End of Life Considerations: Corrosion, Mechanical Strength, and Small Bore Geometry
ASME 2010 Pressure Vessels and Piping Conference: Volume 1, 2010Co-Authors: Dennis K. WilliamsAbstract:This paper discusses the prescribed requirements contained within the ASME B31.3 Process Piping Code that specifically address the considerations of the design Corrosion Allowance when coincidently taken into account with the mechanical strength requirements of the same. In particular, the most significant effects of the least favorable Corrosion Allowances in combination with the mechanical strength requirements of ASME B31.3 are prevalent in thin walled, small bore piping of minimal geometric properties associated with the calculation of component stresses in the longitudinal direction. Careful examination of ASME B31.3 paragraph 302.4 reveals that the minimum required thickness of a piping component include Allowances for Corrosion and when taken in conjunction with paragraph 302.4.1, which requires that when necessary, the wall thickness shall be increased to prevent overstress, damage, or collapse, due to superimposed loads from handling or other causes. The effects of the aforementioned Code requirements are addressed and examples are presented for small bore piping (nps 2″ and below) that lead to a proposed small bore piping criteria for consideration by piping specification engineers. Finally, the results of the evaluation of various combinations of Corrosion Allowance and mechanical strength requirements in terms of metal cross sectional area and section modulus are presented in tabular form that support the proposed small bore piping criteria.Copyright © 2010 by ASME
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ASME B31.3 End of Life Considerations: Corrosion, Mechanical Strength, and Small Bore Geometry
ASME 2010 Pressure Vessels and Piping Conference: Volume 1, 2010Co-Authors: Dennis K. WilliamsAbstract:This paper discusses the prescribed requirements contained within the ASME B31.3 Process Piping Code that specifically address the considerations of the design Corrosion Allowance when coincidently taken into account with the mechanical strength requirements of the same. In particular, the most significant effects of the least favorable Corrosion Allowances in combination with the mechanical strength requirements of ASME B31.3 are prevalent in thin walled, small bore piping of minimal geometric properties associated with the calculation of component stresses in the longitudinal direction. Careful examination of ASME B31.3 paragraph 302.4 reveals that the minimum required thickness of a piping component include Allowances for Corrosion and when taken in conjunction with paragraph 302.4.1, which requires that when necessary, the wall thickness shall be increased to prevent overstress, damage, or collapse, due to superimposed loads from handling or other causes. The effects of the aforementioned Code requirements are addressed and examples are presented for small bore piping (nps 2″ and below) that lead to a proposed small bore piping criteria for consideration by piping specification engineers. Finally, the results of the evaluation of various combinations of Corrosion Allowance and mechanical strength requirements in terms of metal cross sectional area and section modulus are presented in tabular form that support the proposed small bore piping criteria.Copyright © 2010 by ASME
R.d. Mccright - One of the best experts on this subject based on the ideXlab platform.
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Impact of thermal loading on waste package material performance
Transactions of the American Nuclear Society, 2011Co-Authors: D Stahl, J. K. Mccoy, R.d. MccrightAbstract:This report focuses on the prediction of materials performance for the carbon steel Corrosion-Allowance container as a function of thermal loading for the potential repository at Yucca Mountain. Low, intermediate and high thermal loads were evaluated as to their performance given assumptions regarding the temperature and humidity changes with time and the resultant depth of Corrosion penetration. The reference case involved a kinetic relation for Corrosion that was utilized in a sensitivity analysis to examine the impacts of time exponent, pitting, and mirobiologically-influenced Corrosion. As a result of this study, the high thermal load appears to offer the best Corrosion performance. However, other factors must be considered in making the final thermal loading decision.
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Modeling the Corrosion of high-level waste containers: CAM-CRM interface
1998Co-Authors: P.j. Bedrossian, Joseph C. Farmer, R.d. MccrightAbstract:A key component of the Engineered Barrier System (EBS) being designed for containment of spent-fuel and high-level waste at the proposed geological repository at Yucca Mountain, Nevada is a two-layer canister. In this particular design, the inner barrier is made of a Corrosion resistant material (CRM) such as Alloy 825, 625 or C-22, while the outer barrier is made of a Corrosion-Allowance material (CAM) such as A516 or Monel 400. At the present time, Alloy C-22 and A516 are favored. This publication addresses the development of models to account for Corrosion of Alloy C-22 surfaces exposed directly to the Near Field Environment (NFE), as well as to the exacerbated conditions in the CAM-CRM crevice.
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Crevice Corrosion {ampersand} pitting of high-level waste containers: integration of deterministic {ampersand} probabilistic models
1997Co-Authors: Joseph C. Farmer, R.d. MccrightAbstract:A key component of the Engineered Barrier System (EBS) being designed for containment of spent-fuel and high-level waste at the proposed geological repository at Yucca Mountain, Nevada is a two-layer canister. In this particular design, the inner barrier is made of a Corrosion resistant material (CRM) such as Alloy 625 or C-22, while the outer barrier is made of a Corrosion-Allowance material (CAM) such as carbon steel or Alloy 400. An integrated predictive model is being developed to account for the effects of localized environmental conditions in the CRM-CAM crevice on the initiation and propagation of pits through the CRM.
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LONG-TERM Corrosion TESTING OF CANDIDATE MATERIALS FOR HIGH-LEVEL RADIOACTIVE WASTE CONTAINMENT
1997Co-Authors: J. C. Estill, R.d. Mccright, S. Doughty, G. E. Gdowski, S R Gordon, Kenneth J. King, F. WangAbstract:Preliminary results are presented from the long-term Corrosion test program of candidate materials for the high-level radioactive waste packages that would be emplaced in the potential repository at Yucca Mountain, Nevada. The present waste package design is based on a multi-barrier concept having an inner container of a Corrosion resistant material and an outer container of a Corrosion Allowance material. Test specimens have been exposed to simulated bounding environments that may credibly develop in the vicinity of the waste packages. Corrosion rates have been calculated for weight loss and crevice specimens, and U-bend specimens have been examined for evidence of stress Corrosion cracking (SCC). Galvanic testing has been started recently and initial results are forthcoming. Pitting characterization of test specimens will be conducted in the coming year. This test program is expected to continue for a minimum of five years so that long-term Corrosion data can be determined to support Corrosion model development, performance assessment, and waste package design.
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Engineered materials characterization report for the Yucca Mountain Site Characterization Project. Volume 2, Design data
1995Co-Authors: R.a. Konynenburg, R.d. Mccright, A.k. Roy, D.a. JonesAbstract:This is Volume 2 of the Engineered Materials Characterization Report which presents the design data for candidate materials needed in fabricating different components for both large and medium multi-purpose canister (MPC) disposal containers, waste packages for containing uncanistered spent fuel (UCF), and defense high-level waste (HLW) glass disposal containers. The UCF waste package consists of a disposal container with a basket therein. It is assumed that the waste packages will incorporate all-metallic multibarrier disposal containers to accommodate medium and large MPCs, ULCF, and HLW glass canisters. Unless otherwise specified, the disposal container designs incorporate an outer Corrosion-Allowance metal barrier over an inner Corrosion-resistant metal barrier. The Corrosion-Allowance barrier, which will be thicker than the inner Corrosion-resistant barrier, is designed to undergo Corrosion-induced degradation at a very low rate, thus providing the inner barrier protection from the near-field environment for a prolonged service period.
Ong Shiou Ting - One of the best experts on this subject based on the ideXlab platform.
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Optimization of Corrosion Allowance for Substructure Splash Zone Area
2013Co-Authors: Ong Shiou Ting, Fasri Mohd Fadzli, Narayanan Sambu PottyAbstract:Corrosion in Marine and Offshore Structures such as platform substructure is one of the issues to be considered during the design stage. The current Corrosion Allowance (CA) at the splash zone area for platform substructure in Malaysia is 12mm based on 30 years design life without considering the effect of coating performance and cathodic protection for the submerged splash zone area. This issue is crucial because many of the around 200 platforms and other marine structures in Malaysia are reaching their design life (DL) and a lower Corrosion Allowance would mean that they can continue to be used without strengthening the structures. The main objective of this study is to optimize the Corrosion Allowance for substructure splash zone areas for tropical climate recommended to new facilities in tropical climates (seawater surface temperature >20°C, e.g. Malaysia, Indonesia, Myanmar, Vietnam, etc). Herein, a study is conducted to reduce the requirement of Corrosion Allowance to 6mm on thickness for primary members of the jacket by gathering and correlating all the available codes and standard, analysis of actual field data, correlation between coating and cathodic protection effect towards splash zone. The implementation of the optimized Corrosion Allowance would benefit the owners of the marine structures such as oil and gas companies in terms of reduction in material and fabrication cost.
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Marine Corrosion of mild steel at Lumut, Perak
2012Co-Authors: Ong Shiou Ting, Narayanan Sambu Potty, Mohd Shahir LiewAbstract:The Corrosion rate of structural steels in the adverse marine and offshore environments affects the economic interest of offshore structures since the loss of steel may have significant impact on structural safety and performance. With more emphasis to maintain existing structures in service for longer time and hence to defer replacement costs, there is increasing interest in predicting Corrosion rate at a given location for a given period of exposure once the protection coating or cathodic protection is lost. The immersion depth, salinity, steel composition and water pollution will be taken into account. Various Corrosion Allowances are prescribed for structural members by different standards. There are no studies to determine the appropriate Corrosion Allowance for steel structures in marine environment in Malaysia. The objectives of the research are to determine the nature and rate of Corrosion in mm/year for steel structures in marine environment. It also tries to identify whether the Corrosion rate i...
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Prediction of Corrosion rates in marine and offshore structures
2011 National Postgraduate Conference, 2011Co-Authors: Ong Shiou Ting, Narayanan Sambu Potty, M. Shahir LiewAbstract:The Corrosion rate of structural steels in the hostile environments of the coastal, harbour or ocean zones effects the economic interest of offshore structures since both the loss of steel and pitting may have significant impacts on structural safety and performance. With the increasing emphasis to maintain existing structures in service for longer periods of time and hence to defer replacement costs, there is increasing interest in predicting Corrosion rate at a given location for a given period of exposure once the protection (coating or cathodic protection) is lost. A more accurate approach for engineering purposes is to develop predictive Corrosion Allowance based on Corrosion science, marine microbiology and good quality field data. The immersion depth, salinity, steel composition and water pollution will be taken into account to obtain useful data. The underlying approach is probabilistic because the input is not known precisely and may be natural phenomena such as weather conditions.
Robin Gordon - One of the best experts on this subject based on the ideXlab platform.
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An Investigation of the Tolerance of Riser to Corrosion Pitting
Volume 4B: Pipeline and Riser Technology, 2013Co-Authors: Yetzirah Urthaler, Mark Cerkovnik, Fengjie Yin, David Saldana, Robin GordonAbstract:When risers are designed it is common for Corrosion to be accounted for by including a Corrosion Allowance in the wall thickness [3]. However, when designing risers which are subject to fatigue loading from various sources, simply allowing extra thickness in the wall is inadequate to protect against the accelerated fatigue crack growth driven by Corrosion.This paper illustrates a methodology for assessing the fitness for service of a steel catenary riser with various levels of pitting Corrosion. The methodology uses FEA tools, as well as classical fracture mechanics, to predict the rates of crack growth and arrive at predictions of life. Once Corrosion begins and pits form, the structure may experience an increase in crack growth rate, caused by the influence of the chemistry of the produced fluid on the steel and by the stress effects of the pit geometry. Further complications arise if extreme storms cause riser stresses to exceed yield, which then requires the use of strain based methodology.The results of the illustrative study demonstrate that riser designs should account for the potential of accelerated crack growth where there is a potential for pitting Corrosion, and that by only adding a Corrosion Allowance to account for loss of burst capacity, an inadequate design can easily result.Copyright © 2013 by ASME
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AN INVESTIGATION OF THE TOLERANCE OF RISER FATIGUE TO Corrosion PITTING
2013Co-Authors: Yetzirah Urthaler, Mark Cerkovnik, Fengjie Yin, David Saldana, Robin GordonAbstract:When risers are designed it is common for Corrosion to be accounted for by including a Corrosion Allowance in the wall thickness [3]. However, when designing risers which are subject to fatigue loading from various sources, simply allowing extra thickness in the wall is inadequate to protect against the accelerated fatigue crack growth driven by Corrosion. This paper illustrates a methodology for assessing the fitness for service of a steel catenary riser with various levels of pitting Corrosion. The methodology uses FEA tools, as well as classical fracture mechanics, to predict the rates of crack growth and arrive at predictions of life. Once Corrosion begins and pits form, the structure may experience an increase in crack growth rate, caused by the influence of the chemistry of the produced fluid on the steel and by the stress effects of the pit geometry. Further complications arise if extreme storms cause riser stresses to exceed yield, which then requires the use of strain based methodology. The results of the illustrative study demonstrate that riser designs should account for the potential of accelerated crack growth where there is a potential for pitting Corrosion, and that by only adding a Corrosion Allowance to account for loss of burst capacity, an inadequate design can easily result.
