A new burst pressure model for thin-walled pipe elbows containing metal-loss corrosion defects

2019 ◽  
Vol 200 ◽  
pp. 109720 ◽  
Author(s):  
Qingguo Wang ◽  
Wenxing Zhou
Keyword(s):  
Burst Pressure ◽  
Metal Loss ◽  
Thin Walled Pipe ◽  
Corrosion Defects ◽  
Thin Walled

Repair of Leaks in Thin Wall High Pressure Pipelines Using Composite Reinforcing Technologies

2020 ◽  
Author(s):  
Chris Alexander ◽  
Salem Talbi ◽  
Richard Kania ◽  
Jon Rickert
Keyword(s):  
High Pressure ◽  
Operating Conditions ◽  
Thin Wall ◽  
Nitrogen Gas ◽  
Composite Repair ◽  
Pressure Cycling ◽  
Thin Walled Pipe ◽  
Corrosion Defects ◽  
Thin Walled ◽  
Pipe Materials

Abstract A study was conducted to evaluate two composite repair technologies used to reinforce severe corrosion and thru-wall leaking defects in thin-walled pipe materials; conditions where the welding of conventional Type B steel sleeves cannot be conducted. This program involved the reinforcement of simulated 85% corrosion defects in 6.625-inch × 0.157-inch, Grade X52 pipe materials subjected to cyclic pressure and burst testing. The test matrix also included repaired pipe samples with thru-wall defects that were pressurized using nitrogen gas and buried for 90 days. The program was comprehensive in that it evaluated the following elements involving a total of 81 reinforced corrosion defects. • Corrosion features with a depth of 85% of the pipe’s nominal wall thickness in thin-walled pipe material (i.e., 0.157 inches, or 4 mm). • Thru-wall defects having a diameter of 0.125 inches (3 mm). • Repairs made with leaking defects having 100 psig (690 kPa) internal pressure. • Strain gage measurement made in non-leaking 85% corrosion defects; it should be noted that the remaining “15%” ligament was 0.024 inches (0.6 mm); to the author’s knowledge, no high-pressure testing has ever been conducted on such a thin remaining wall. • Long-term 90-day test that included pressurization with nitrogen gas, followed by relatively aggressive pressure cycling up to 80% SMYS followed by burst testing. This is the first comprehensive study conducted by a major transmission pipeline operator evaluating the performance of competing composite technologies used to reinforce severe corrosion features with thru-wall defects. The reinforcement of leaks has not been accepted by regulatory bodies such as the Canadian Energy Regulator (CER), or the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA). A goal of the current study is to validate composite repair technologies as a precursor to regulatory approval. The results of this study indicate that viable composite repair technologies exist with capabilities to reinforce leaks in pipelines that experience operating conditions typical for gas transmission systems (i.e., minimal pressure cycling).

scholarly journals A FEA Method for Mathematical Calculation and Prediction Analysis Cross-sectional Ovalization of Tubes under Rotary Straightening

2021 ◽  
Vol 2083 (4) ◽  
pp. 042057
Author(s):  
Ziqian Zhang ◽  
Ying Zhong
Keyword(s):  
Process Parameters ◽  
Element Model ◽  
Simulation Method ◽  
Stress And Strain ◽  
Cross Sectional ◽  
Bending Deformation ◽  
Deformation Stage ◽  
Thin Walled Pipe ◽  
Thin Walled ◽  
Flattening Process

Abstract The section flattening phenomenon (namely Bazier effect) will occur in the large bending deformation stage of thin-walled pipe in the continuous straightening process. The maximum section flattening amount and the residual section flattening amount are important process parameters, which are the basis for calculating the subsequent process parameters of the flattening circle, and directly determine the roundness of the final pipe and the product quality. However, it is hard to be obtained by the theoretical or experimental methods. Therefore, based on the structure and process parameters of the leveler, a finite element model was built to simulate the section flattening process. Then, ANSYS/LS-DYNA software was used to dynamically simulate the bending flattening phenomenon of thin-walled pipe in the continuous straightening process, and the stress and strain nephographic of the flattening deformation zone was obtained. By recording the position curve of the key nodes in the preventing process, the section flattening amount of the thin-walled pipe in the large bending deformation stage in the continuous straightening process was determined. The simulation results show that the dynamic simulation method can effectively predict the section flattening of thin-walled pipe in the process of continuous straightening.

Meshless Simulation of Fracture in Thin-Walled Pipe Structures

2009 ◽  
Author(s):  
S. J. Liu
Keyword(s):  
Dynamic Fracture ◽  
Fracture Criterion ◽  
Sph Method ◽  
Shell Analysis ◽  
Stress Point ◽  
Particle Hydrodynamics ◽  
Thin Walled Pipe ◽  
Smoothed Particle ◽  
Point Integration ◽  
Thin Walled

A meshless shell method for dynamic fracture problems based on normalized Smoothed Particle Hydrodynamics (SPH) is presented. The SPH method is corrected by a normalization in order to fulfill completeness requirement. Instability are controlled by stress-point integration. The method is modified for Mindlin-Reissner shell analysis. Stress based fracture criterion is incorporated based on the visibility method. The method is applied to two dynamic fracture problems in thin-walled pipes including fluid-structure interaction. The results are compared to experimental data and they are very promising.

Effect of Thickness Measurement Procedure on Stress Analysis of Pipes With Local Metal Loss

2013 ◽  
Author(s):  
Nobuyuki Yoshida ◽  
Atsushi Yamaguchi
Keyword(s):  
Decision Making ◽  
Measurement Procedure ◽  
Thickness Measurement ◽  
Burst Pressure ◽  
Metal Loss ◽  
Element Analysis ◽  
Fea Model ◽  
Laser Displacement Meter ◽  
The Difference ◽  
Corrosion Under Insulation

Fitness-For-Service (FFS) assessment using Finite Element Analysis (FEA) has been a problem in deciding yes-no which vary from evaluator to evaluator. The difference in decision making is caused by the degree of freedom in modeling a FEA model. In this study, burst pressures of pipes with local metal loss were calculated by using FEA in order to investigate the influence of thickness measurement intervals on FFS assessment. The analyzed pressures by FEA were verified by burst tests. A pipe specimen, which was thinned by corrosion under insulation in the actual plant, was used for the burst tests. Shape of the pipe specimen was measured by laser displacement meter and extracted at several types of interval. It is concluded that the analyzed pressures in various measurement intervals showed almost no difference, but were higher than the actual burst pressure of the specimen.

Validating ILI Accuracy Using API 1163

2014 ◽  
Author(s):  
Lucinda Smart ◽  
Harvey Haines
Keyword(s):  
Burst Pressure ◽  
Metal Loss ◽  
Internal Corrosion ◽  
Know How ◽  
Pressure Calculation ◽  
Loss Data ◽  
Pipeline Segment ◽  
External Corrosion ◽  
Corrosion Pits

It is important to validate the accuracy of in-line inspection (ILI) tools to know how many excavations are needed to maintain the integrity of a pipeline segment. Performing sufficient excavations is important to ensure there are no defects left in the pipeline that have even a remote chance of failure. In some cases additional excavations may be necessary to ensure safety where in other cases no excavations may be necessary. This paper looks at using spatially recorded metal-loss data collected “in-the-ditch” to measure the accuracy of ILI tool results. Examples of spatial in-ditch data are laser scans for external corrosion and UT scans for internal corrosion. Spatially mapped metal loss, because all of the corrosion area is mapped, has the advantage of allowing more comparisons to be made for a given corrosion area and also allows the interaction among corrosion pits to be studied for examining burst pressure calculation accuracy. From our studies we find the depth error for shallow corrosion 10%–20% wt deep is often not representative of deeper corrosion in the same pipeline and the interaction criteria for ILI tools needs to be larger than the interaction criteria for in-ditch data. Examples are shown with these types of results, and by interpreting the results in conjunction with API 1163, certain ILI runs are shown that require no excavations where others may require additional excavations than suggested by normal +/−10% wt ILI data.

Assessment of Interacting Corrosion Defects in Thin-Walled Pipes

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Ahmed A. Soliman ◽  
Mohammad M. Megahed ◽  
Ch. A. Saleh ◽  
Mostafa Shazly
Keyword(s):  
Nonlinear Finite Element ◽  
Metal Loss ◽  
Test Results ◽  
Defect Depth ◽  
Element Analysis ◽  
Shell Elements ◽  
Codes Of Practice ◽  
Useful Life ◽  
Corrosion Defects ◽  
Interaction Rule

Abstract Corrosion in pipes is usually found in the form of closely spaced defects, which eventually reduce the pipe pressure carrying capacity and piping planned useful life. Codes and standards have been developed to evaluate the effect of such form of metal loss on the piping pressure carrying capacities. However, predictions of such codes are usually conservative, and hence, there is a need to assess their degree of conservatism. The present paper utilizes nonlinear finite element analysis (FEA) in estimating pressure carrying capacities of defective pipes, and hence provides an evaluation of codes degree of conservatism. Shell elements with reduced thickness at the corrosion defect are adopted and their accuracy is assessed by comparison with those of solid elements as well as experimental test results. The influence of defects interaction is investigated by considering two neighboring defects in an inclined direction to each other. The influence of inclination angle, inclined proximity distance between the two defects, and the defect depth to wall thickness ratio are investigated. Comparisons were made with predictions of codes of practice in all cases. Code predictions were found to be conservative compared to FEA results. Furthermore, the interaction rule embedded in the codes for checking for interaction leads to inaccurate predictions for closely spaced defects as it does not include the effect of defect depth.

Working Body for Deformation of Thin-Walled Pipe Billets

2019 ◽  
Vol 945 ◽  
pp. 628-633 ◽  
Author(s):  
S.B. Maryin ◽  
Phyo Wai Aung
Keyword(s):  
Production Costs ◽  
Compression Load ◽  
Advantages And Disadvantages ◽  
Different Types ◽  
Thin Walled Pipe ◽  
Thin Walled ◽  
Working Bodies ◽  
Fast Flow ◽  
Rigid Matrix ◽  
Transfer Pressure

In this paper we consider different types of working bodies and fillers used in the manufacture of hydro-gas systems of aircraft from thin-walled pipe billets, and also explored the advantages and disadvantages of liquid, fusible, solid, elastic, loose and combined fillers in the deformation of pipe segments by means of distribution, crimping, forming and flexible. As a result of the research, a device for distributing pipe billets along a rigid matrix and a working body made of granular polyurethane and ice, the main advantages of which are: good rheological properties (fast flow); high ductility and viscosity; high ability to transfer pressure throughout the metal zone; ability to withstand high compression load; ease of entry into the workpiece and removal from the finished part; low production costs.

Validity of the LAPA Method for Assessment of Defects Reported by In-Line Inspection Tools

2004 ◽  
Author(s):  
Richard Fletcher ◽  
Louis Fenyvesi
Keyword(s):  
Alternative Assessment ◽  
Reliable Method ◽  
Burst Pressure ◽  
Independent Validation ◽  
Defect Profile ◽  
Corrosion Defects ◽  
Pipeline Corrosion

Over recent years, RSTRENG has gained acceptance as a reliable method of assessing the effect of pipeline corrosion defects, while reducing the conservatism inherent in some of the alternative assessment models. The Length Adaptive Pressure Assessment (LAPA) algorithm has been developed to apply an adaptation of the RSTRENG methodology directly to the results of a magnetic in-line inspection. Adoption of the LAPA technique offers substantial accuracy and efficiency benefits over the more conventional processes, but the industry requires confirmation of the method’s validity before it can take advantage of these. The paper will describe the LAPA validation work performed by PII, and independent validation undertaken by TransCanada Pipelines and other pipeline operators. The independent validation took the form of a comparison of LAPA-based burst pressure calculations with RSTRENG calculations based on direct infield measurements of the defect profile. TransCanada also performed a series of burst tests to quantify the accuracy of the LAPA calculations.

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