Corrosion Assessment Method Validation for High-Grade Line Pipe

2010 ◽  
Author(s):  
Michael Besel ◽  
Steffen Zimmermann ◽  
Christoph Kalwa ◽  
Theo Ko¨ppe ◽  
Andreas Liessem
Keyword(s):  
Plastic Flow ◽  
Predictive Accuracy ◽  
Plastic Material ◽  
Assessment Method ◽  
Burst Pressure ◽  
High Grade ◽  
Line Pipe ◽  
Corrosion Defect ◽  
Von Mises Plasticity ◽  
Grade Steel

The present paper deals with the pressure containment and deformation capacity of corroded high-grade steel line pipe. Firstly, some well established models are investigated concerning their predictive accuracy if applied to high-grade line pipe steel. In particular, it will be shown that all models under consideration tend to overestimate the remaining strength in the case of high-grade steel pipes. Afterwards, FE-analyses are performed in order to study the local evolution of plastic flow in the area of the corrosion defect; at the same time, the burst pressure is predicted applying von Mises plasticity and a simple failure criterion. Although different defect geometries are associated with well pronounced differences in the evolution of the plastic flow around the corrosion defect no significant effect on the burst pressure is found. Finally, the main results of a hydrostatic burst test performed on a pristine X100 line pipe joint are presented. It appears that the material under consideration seems to have anisotropic plastic material properties which may have effect on burst pressure.

Through-wall yield ductile burst pressure of high-grade steel tube and casing with and without corroded defect

2020 ◽  
pp. 102902
Author(s):  
Deng Kuanhai ◽  
Peng Yang ◽  
Liu Bing ◽  
Lin Yuanhua ◽  
Wang Jiandong
Keyword(s):  
Steel Tube ◽  
Burst Pressure ◽  
High Grade ◽  
Grade Steel

On the effect of long corrosion defect and axial tension on the burst pressure of subsea pipelines

2021 ◽  
Vol 111 ◽  
pp. 102637
Author(s):  
Zhan-Feng Chen ◽  
Wen Wang ◽  
He Yang ◽  
Sun-Ting Yan ◽  
Zhi-Jiang Jin
Keyword(s):  
Burst Pressure ◽  
Corrosion Defect ◽  
Axial Tension ◽  
Subsea Pipelines

Theory and Application of the Parallel-Plate Plastimeter. Part 2

1935 ◽  
Vol 8 (4) ◽  
pp. 587-596 ◽  
Author(s):  
J. R. Scott
Keyword(s):  
Plastic Flow ◽  
Parallel Plate ◽  
Plastic Material ◽  
Compressive Load ◽  
Flow Equation ◽  
Simple Type ◽  
Plastic Properties ◽  
Further Development ◽  
Rubber Stock ◽  
Existing Data

Abstract In Part I (loc. cit.) the behavior of a plastic material in the parallel-plate (Williams) plastimeter was studied, and an expression was deduced showing how the rate of decrease in thickness of the sample during compression depends on the volume of the sample, its plastic properties, the compressive load, and the thickness itself. Subsequently, observations were published which showed that the basic principle adopted in this study was incorrect in certain particulars. Peek (loc. cit.), using these observations as a basis, deduced a new expression for the rate of decrease in thickness, though this is too complex for convenient practical use, except in an approximate simplified form. It has now been shown that the expression deduced in Part I, in spite of the inaccurate basis used, is sufficiently near to the truth to render substantially correct the conclusions there stated concerning the plastic properties of unvulcanized rubber stocks. By adopting the more accurate basis used by Peek, moreover, expressions for the rate of decrease in thickness can be deduced for materials showing more complex types of plastic flow than that considered in Part I or by Peek; this had proved impossible by the method previously used. The expression obtained by Peek for the simple type of plastic flow, as well as those now deduced for the more complex types, can be expressed in a form that furnishes a simple and rapid method of examining and analyzing experimental results. As a result of the work described in this paper, it is thus possible to determine, from results obtained with the parallel-plate plastimeter, whether or not a material such as unvulcanized rubber stock exhibits any of the types of plastic flow represented in the general form by Equation 1, and, if so, to find the values of the plastic constants of the material. The procedure is similar to that described in Part I, and consists simply in comparing, by superposition, a set of standard curves drawn on transparent paper with the curve plotted from experimental data. This further development of the method of studying plastic properties by means of the parallel-plate plastimeter should greatly increase its utility as an instrument of research. It has not yet been possible to apply the new method to a systematic study of rubber stocks, but from an examination of existing data it appears that these stocks, tested at 90° C., agree approximately with various forms of the generalized plastic flow equation already referred to.

Rubber Plastometer with Uniform Rate of Shear—Shearing-Cone Plastometer

1946 ◽  
Vol 19 (3) ◽  
pp. 822-831 ◽  
Author(s):  
G. H. Piper ◽  
J. R. Scott
Keyword(s):  
Plastic Flow ◽  
Mechanical Design ◽  
Plastic Material ◽  
Edge Zone ◽  
Uniform Rate ◽  
Wide Range

Abstract A new shearing-cone plastometer, suitable for investigating the plastic-flow relations of highly viscous materials over a wide range of stress, is described. A mushroom-shaped rotor, having upper and lower surfaces of conical type, is rotated in the plastic material contained in a cylindrical mould. With this type of shearing surface the rate of shear is uniform throughout the material, except for a small edge zone, thus overcoming some disadvantages of previous plastometers. The mechanical design is based on the Mooney shearing-disk plastometer except that provision is made for a wide range of speeds of rotation.

Girth Weld Strength Matching Effect on Tensile Strain Capacity of Grade X70 High Strain Line Pipe

2018 ◽  
Author(s):  
Hisakazu Tajika ◽  
Takahiro Sakimoto ◽  
Tsunehisa Handa ◽  
Rinsei Ikeda ◽  
Joe Kondo
Keyword(s):  
High Strain ◽  
Limit State ◽  
Full Scale ◽  
Bending Test ◽  
High Grade ◽  
Line Pipe ◽  
Bending Tests ◽  
Strain Capacity ◽  
Pipeline Project ◽  
Pipe Bending

Recently high grade pipeline project have been planned in hostile environment like landslide in mountain area, liquefaction in reclaimed land or the frost heave in Polar Regions. Geohazards bring large scale ground deformation and effect on the varied pipeline to cause large deformation. Therefore, strain capacity is important for the pipeline and strain based design is also needed to keep gas transportation project in safe. High grade steel pipe for linepipe tends to have higher yield to tensile (Y/T) ratio and it has been investigated that the lower Y/T ratio of the material improves strain capacity in buckling and tensile limit state. In onshore pipeline project, pipe usually transported in 12 or 18m each and jointed in the field. Girth weld (GW) is indispensable so strength matching of girth weld towards pipe body is important. In this study strain capacity of Grade X70 high strain pipes with size of 36″ OD and 23mm WT was investigated with two types of experiments, which are full scale pipe bending tests and curved wide plate tests. The length of the specimen of full scale bending tests were approximately 8m and girth weld was made in the middle of joint length. A fixed internal pressure was applied during the bending test. Actual pipe situation in work was simulated and both circumferential and longitudinal stress occurred in this test. Test pipes were cut and welded, GTAW in first two layer and then finished by GMAW. In one pipe, YS-TS over-matching girth weld (OVM) joint was prepared considering the pipe body grade. For the other pipe, intentionally under-matching girth weld (UDM) joint was prepared. After the girth welding, elliptical EDM notch were installed in the GW HAZ as simulated weld defect. In both pipe bending tests, the buckling occurred in the pipe body at approximately 300mm apart from the GW and after that, deformation concentrated to buckling wrinkle. Test pipe breaking locations were different in the two tests. In OVM, tensile rupture occurred in pipe body on the backside of buckling wrinkle. In UDM, tensile rupture occurred from notch in the HAZ. In CWP test, breaking location was the HAZ notch. There were significant differences in CTOD growth in HAZ notch in these tests.

scholarly journals Development of a Genomic Signatures-Based Predictor of Initial Platinum-Resistance in Advanced High-Grade Serous Ovarian Cancer Patients

2021 ◽  
Vol 10 ◽  
Author(s):  
Yuan Li ◽  
Xiaolan Zhang ◽  
Yan Gao ◽  
Chunliang Shang ◽  
Bo Yu ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Predictive Accuracy ◽  
Predictive Performance ◽  
Platinum Resistance ◽  
High Grade ◽  
Serous Ovarian Cancer ◽  
Single Nucleotide Variants ◽  
Tissue Samples ◽  
Platinum Sensitive ◽  
Platinum Based Chemotherapy

BackgroundHigh grade serous ovarian cancer (HGSOC) is the most common subtype of ovarian cancer. Although platinum-based chemotherapy has been the cornerstone for HGSOC treatment, nearly 25% of patients would have less than 6 months of interval since the last platinum chemotherapy, referred to as platinum-resistance. Currently, no precise tools to predict platinum resistance have been developed yet.MethodsNinety-nine HGSOC patients, who have finished cytoreductive surgery and platinum-based chemotherapy in Peking University Third Hospital from 2018 to 2019, were enrolled. Whole-genome sequencing (WGS) and whole-exome sequencing (WES) were performed on the collected tumor tissue samples to establish a platinum-resistance predictor in a discovery cohort of 57 patients, and further validated in another 42 HGSOC patients.ResultsA high prevalence of alterations in DNA damage repair (DDR) pathway, including BRCA1/2, was identified both in the platinum-sensitive and resistant HGSOC patients. Compared with the resistant subgroup, there was a trend of higher prevalence of homologous recombination deficiency (HRD) in the platinum-sensitive subgroup (78.95% vs. 47.37%, p=0.0646). Based on the HRD score, microhomology insertions and deletions (MHID), copy number changes load, duplication load of 1–100 kb, single nucleotide variants load, and eight other mutational signatures, a combined predictor of platinum-resistance, named as DRDscore, was established. DRDscore outperformed in predicting the platinum-sensitivity than the previously reported biomarkers with a predictive accuracy of 0.860 at a threshold of 0.7584. The predictive performance of DRDscore was validated in an independent cohort of 42 HGSOC patients with a sensitivity of 90.9%.ConclusionsA multi-genomic signature-based analysis enabled the prediction of initial platinum resistance in advanced HGSOC patients, which may serve as a novel assessment of platinum resistance, provide therapeutic guidance, and merit further validation.

Electrochemical Corrosion Finite Element Analysis and Burst Pressure Prediction of Externally Corroded Underground Gas Transmission Pipelines

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Ibrahim M. Gadala ◽  
Magd Abdel Wahab ◽  
Akram Alfantazi
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Reaction Kinetics ◽  
Moving Boundary ◽  
Electrochemical Corrosion ◽  
Burst Pressure ◽  
Element Analysis ◽  
Corrosion Defect ◽  
Nonlinear Stress ◽  
Pipeline Wall

An integrative numerical simulation approach for pipeline integrity analysis is presented in this work, combining a corrosion model, which is the main focus of this paper, with a complementary structural nonlinear stress analysis, using the finite element method (FEM). Potential distributions in the trapped water existing beneath pipeline coating disbondments are modeled in conjunction with reaction kinetics on the corroding exposed steel surface using a moving boundary mesh. Temperature dependencies (25 °C and 50 °C) of reaction kinetics do not greatly affect final corrosion defect geometries after 3-yr simulation periods. Conversely, cathodic protection (CP) levels and pH dependencies within the near-neutral pH range (6.7–8.5) strongly govern depth profiles caused by corrosion, reaching a maximum of ∼3 mm into the pipeline wall. A 0.25 V amplification of CP potential combined with a 0.5 mm widening in disbondment opening size reduces defect penetration by almost 30%. Resulting corrosion defect geometries are used for stress examinations and burst pressure evaluations. Furthermore, nonlinear elastic–plastic stress analysis is carried out using shell elements in order to predict the burst pressure of corroded pipes. Corrosion is modeled by reducing the stiffness of a damaged element that has the dimensions of the defect. The predicted burst pressures are in good agreement with those obtained using an experimental-based formula.

Strength Criteria Versus Plastic Flow Criteria Used in Pressure Vessel Design and Analysis1

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Xian-Kui Zhu
Keyword(s):  
Plastic Flow ◽  
Pressure Vessel ◽  
Yield Criterion ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Thin Wall ◽  
Strength Criteria ◽  
Integrity Assessment ◽  
Ductile Materials ◽  
Strength Design Criteria

This paper presents a critical comparison of the traditional strength criteria and the modern plastic flow criteria used in the structural design and integrity assessment of pressure vessels. This includes (1) a brief review of the traditional strength criteria used in the ASME Boiler and Pressure Vessel (B&PV) Code, (2) a discussion of the shortcomings of the traditional strength criteria when used to predict the burst pressure of pressure vessels, (3) an analysis of challenges, technical gaps, and basic needs to improve the traditional strength criteria, (4) a comparison of strength theories and plasticity theories for ductile materials, (5) an evaluation of available plastic flow criteria and their drawbacks in prediction of burst pressure of pressure vessels, (6) a description of a newly developed multiaxial yield criterion and its application to pressure vessels, and (7) a demonstration of experimental validation of the new plastic flow criterion when used to predict the burst pressure of thin-wall pressure vessels. Finally, recommendations are made for further study to improve the traditional strength design criteria and to facilitate utilization of the modern plastic flow criteria for pressure vessel design and analysis.

Evaluation of Strength Design Criteria and Plastic Flow Criteria for Pressure Vessels

2014 ◽  
Author(s):  
Xian-Kui Zhu
Keyword(s):  
Plastic Flow ◽  
Axial Flow ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Design Criteria ◽  
Strength Criteria ◽  
Integrity Assessment ◽  
Strength Design ◽  
Strength Design Criteria ◽  
Flow Criterion

The present paper evaluates the traditional strength design criteria and recently developed plastic flow criteria used in the structural design and integrity assessment for pressure vessels. This includes (1) a brief review of the traditional strength criteria used in ASME Boiler and Pressure Vessel (B&PV) Code, (2) a discussion of the shortcoming of existing strength criteria when used to predict the burst pressure of pressure vessels, (3) an analysis of challenges, technical gaps and basic needs to improve the traditional strength design criteria, (4) a comparison of strength theory and flow theory for ductile pressure vessels, (5) an evaluation of available flow criteria and their shortcoming in prediction of failure pressure of pressure vessels, (6) an introduction of newly developed multi-axial flow criterion and its application to pressure vessels, and (7) a demonstration of experimental validations of the new flow criterion when used to predict the burst pressure of pressure vessels. On this basis, several recommendations are made for further study to improve the existing strength design and integrity assessment methods of pressure vessels.

scholarly journals Correction for Longitudinal Stress in the Assessment of Corroded Line Pipe

1998 ◽  
Author(s):  
K. Andrew Roberts ◽  
Roy J. Pick
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Correction Factor ◽  
Circumferential Stress ◽  
Burst Pressure ◽  
Longitudinal Stress ◽  
Line Pipe ◽  
Element Modeling ◽  
Corrosion Pits ◽  
Assessment Procedures

It is common to assess corroded line pipe using ASME B31-G, its Canadian equivalent CSA Z662 Clause 10.8.2, or more recently RSTRENG. These techniques consider only the circumferential stress in the pipe in predicting the burst pressure of corroded pipe. This paper describes the results of experiments and finite element modeling to investigate the effect of longitudinal stress on the burst pressure of pipe with isolated corrosion pits. The results are used to develop a correction factor applicable to the assessment procedures listed above.

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