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Article
Publication date: 1 February 2021

Yuan-Jian Yang, Guihua Wang, Qiuyang Zhong, Huan Zhang, Junjie He and Haijun Chen

Gas pipelines are facing serious risk because of the factors such as long service life, complex working condition and most importantly, corrosion. As one of the main…

Abstract

Purpose

Gas pipelines are facing serious risk because of the factors such as long service life, complex working condition and most importantly, corrosion. As one of the main failure reasons of gas pipeline, corrosion poses a great threat to its stable operation. Therefore, it is necessary to analyze the reliability of gas pipelines with corrosion defect. This paper uses the corresponding methods to predict the residual strength and residual life of pipelines.

Design/methodology/approach

In this paper, ASME-B31G revised criteria and finite element numerical analysis software are used to analyze the reliability of a special dangerous section of a gas gathering pipeline, and the failure pressure and stress concentration of the pipeline under three failure criteria are obtained. Furthermore, combined with the predicted corrosion rate of the pipeline, the residual service life of the pipeline is calculated.

Findings

This paper verifies the feasibility of ASME-B31G revised criteria and finite element numerical analysis methods for reliability analysis of gas pipelines with corrosion defect. According to the calculation results, the maximum safe internal pressure of the pipeline is 9.53 Mpa, and the residual life of the pipeline under the current operating pressure is 38.41 years, meeting the requirements of safe and reliable operation.

Originality/value

The analysis methods and analysis results provide reference basis for the reliability analysis of corroded pipelines, which is of great practical engineering value for the safe and stable operation of natural gas pipelines.

Details

International Journal of Structural Integrity, vol. 12 no. 6
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 March 2001

P.K. Dey

The existing method of pipeline health monitoring, which requires an entire pipeline to be inspected periodically, is both time‐wasting and expensive. A risk‐based model…

2488

Abstract

The existing method of pipeline health monitoring, which requires an entire pipeline to be inspected periodically, is both time‐wasting and expensive. A risk‐based model that reduces the amount of time spent on inspection has been presented. This model not only reduces the cost of maintaining petroleum pipelines, but also suggests efficient design and operation philosophy, construction methodology and logical insurance plans. The risk‐based model uses Analytic Hierarchy Process (AHP), a multiple attribute decision‐making technique, to identify the factors that influence failure on specific segments and analyzes their effects by determining probability of risk factors. The severity of failure is determined through consequence analysis. From this, the effect of a failure caused by each risk factor can be established in terms of cost, and the cumulative effect of failure is determined through probability analysis. The technique does not totally eliminate subjectivity, but it is an improvement over the existing inspection method.

Details

Journal of Quality in Maintenance Engineering, vol. 7 no. 1
Type: Research Article
ISSN: 1355-2511

Keywords

Article
Publication date: 9 January 2007

Ghada M. Amer

The paper proposes to present the effect of the high voltage transmission lines on the metallic pipelines by calculating the induced voltage due to mutual inductance…

6526

Abstract

Purpose

The paper proposes to present the effect of the high voltage transmission lines on the metallic pipelines by calculating the induced voltage due to mutual inductance between the two circuits especially in short circuit conditions of high voltage overhead transmission lines.

Design/methodology/approach

The electro magnetic transient program (EMTP) is used to simulate the high voltage transmission lines in normal case and in different faulty case conditions. A software is built on MATLAB program (M‐file) to study the effects of various parameters on the magnitude of the induced voltage such as: separation distance between the high voltage transmission line and the metallic pipeline (horizontal distance), different cases of short circuits and normal operation case, the screening factor, and the soil resistivity.

Findings

The three‐phase to ground fault gives the least induced voltage, and phase to ground fault case is the most serious case. The induced voltage decreases with increasing the soil resistivity until 400 Ωm and after this, the induced voltage in the metallic pipeline increases with increasing the soil resistivity for all phase fault types.

Research limitations/implications

It does not deal with all types of interference such as capacitive interference.

Practical implications

This technique helps to know the electrical influence exerted by power line on a pipeline. So it can prevent the pipeline from posing a shock hazard rather than corrosion.

Originality/value

This paper presents the effect of the high voltage transmission lines on the metallic pipelines by calculating the induced voltage due to mutual inductance between the two circuits especially in short circuit conditions of high voltage overhead transmission lines.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 26 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 13 September 2011

Qingjun Zhu, Alin Cao, Wang Zaifend, Jiwen Song and Chen Shengli

The purpose of this paper is to analyze and solve abnormal variation of pipe‐to‐soil potentials of an oil‐transfer pipeline.

Abstract

Purpose

The purpose of this paper is to analyze and solve abnormal variation of pipe‐to‐soil potentials of an oil‐transfer pipeline.

Design/methodology/approach

Pipe‐to‐soil potentials of an oil‐transfer pipeline varied abnormally at several locations. Visual detections find the pipeline is buried near an electric railway and there are several anodic ground beds nearby. Corrosion patterns of the pipeline and examination of the soil reveal no microbiological corrosion. The potential gradients indicate the pipeline might not be attacked by stray currents. However, whole day measurements of one pipeline pile show there are two kinds of stray currents influencing the pipeline: AC stray current and DC stray current.

Findings

The highest pipe‐to‐soil potential reaches 12.958 V when there are AC stray currents. In addition, the biggest and lowest DC pipe‐to‐soil potentials are 0.888 V and −5.90 V, respectively. Radiodetection pipeline current mapper measurement finds there is some bitumen coating breaking points on pipeline. These make the stray currents enter the pipeline and stray current corrosion happens easily. As a result, stray current corrosion happens.

Originality/value

The potential gradients cannot indicate stray current corrosion under all circumstance.

Details

Anti-Corrosion Methods and Materials, vol. 58 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 6 June 2016

Bo Hu, Runqiao Yu and Jian Liu

This paper aims to clarify the transient electromagnetic method used for the nondestructive testing of the corrosion of an in-service buried metal pipeline in trenchless state.

Abstract

Purpose

This paper aims to clarify the transient electromagnetic method used for the nondestructive testing of the corrosion of an in-service buried metal pipeline in trenchless state.

Design/methodology/approach

The paper designed corrosion models indoor and infield for testing. A method for calculating the residual wall thickness of metal pipelines was also proposed. The calculation method was verified by the test results. In the test, the receiving probe was improved by the addition of a Mn-Zn ferrite core. The amplitudes of the test results obviously increased, and the calculation accuracy was improved.

Findings

The paper states that the transient electromagnetic method can detect the uniform corrosion distribution of a certain section of a pipeline. A multi-channel profile of the induced electromotive force and the calculated values of the residual wall thickness can be used to confirm the position and degree of corrosion defects, respectively.

Research limitations/implications

The transient electromagnetic method is more effective for large-area corrosion than for localized corrosion (pitting).

Practical implications

The paper includes implications for the development of nondestructive testing method of the corrosion of an in-service buried metal pipeline.

Originality/value

This paper proved the feasibility and reliability of using transient electromagnetic method to test the corrosion of a buried metal pipeline based on experimental study.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 January 2016

Gan Cui, Zili Li, Chao Yang and Xiaoyong Ding

Under normal conditions, there are different protection objects inside and outside the gas station, so two sets of independent cathodic protection systems are adopted. At…

Abstract

Purpose

Under normal conditions, there are different protection objects inside and outside the gas station, so two sets of independent cathodic protection systems are adopted. At the same time, an insulating flange is applied at the position where trunk pipelines access to the gas station, which realizes electrical isolation of the structures inside and outside the station. However, as a result of short distance between the two cathodic protection systems, there will be stray current interference between them. The purpose of this paper was to study on the interference between cathodic protection systems of gas station and long distance trunk pipeline.

Design/methodology/approach

Based on the above, in this paper, first, the mathematical model of interference between cathodic protection systems was established and the control equations solved using the boundary element method. Second, the influence of cathodic protection system of gas station on long distance trunk pipeline and the influence of cathodic protection system of long distance trunk pipeline on gas station were studied separately using BEASY software. Finally, a new thought of cathodic protection design for local station was put forward.

Findings

It was concluded that there were serious interference problems between the cathodic protection systems of gas station and long distance trunk pipeline. By moving the potential control point to area outside the influence scope of anode ground bed could avoid the influence of cathodic protection system of gas station on long distance trunk pipeline. By moving the auxiliary anodes away from gas station could avoid the influence of cathodic protection system of long distance trunk pipeline on pipelines in gas station. The new thought of cathodic protection design could avoid the interference between the cathodic protection systems effectively.

Originality/value

It is considered that the results can guide cathodic design for gas station and long distance trunk pipeline. The results can also avoid the interference corrosion between the structures in gas station and trunk pipeline.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 17 December 2018

Ziqing Yang, Gan Cui, Zili Li and JianGuo Liu

In recent years, the demand for oil and gas pipelines has increased rapidly. Due to the restrictions of the pipeline routing, pipelines are generally laid in parallel or…

Abstract

Purpose

In recent years, the demand for oil and gas pipelines has increased rapidly. Due to the restrictions of the pipeline routing, pipelines are generally laid in parallel or in the same trench, which results in stray-current interference between the independent cathodic protection (CP) systems. The purpose of this paper is to study the interference between the long-distance parallel pipelines and to obtain the optimized operation for the CP systems.

Design/methodology/approach

In this study, first, the numerical model of parallel pipelines was established using the boundary element analysis software (BEASY). Second, the effects of horizontal distance between parallel pipelines, coating damage rate, soil conductivity and anode output current on the interference of parallel pipelines were studied. Finally, by varying the layout or the output currents of CP stations, an optimized operation scheme osf long-distance parallel pipelines was put forward.

Findings

Simulation results showed that with a decrease in soil conductivity or coating damage rate, the interference increased. Moreover, the interference decreased with an increase in horizontal distance between two parallel pipelines or a decrease in anode output current. It was found that there are three methods to reduce the interference between long-distance parallel pipelines: to reduce the output currents of CP stations, combined protection and to close part of the CP stations. Among them, to close part of CP stations was the optimized scheme because of the lowest operating and maintenance cost.

Originality/value

The optimized operation scheme proposed in this study can not only solve the interference between parallel pipelines but also provide guidance for the parallel pipelines to be built in the future. Reasonably arranging the cathodic protection stations using numerical simulation can avoid the interference in the cathodic protection systems, and reduce the construction cost.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

Book part
Publication date: 22 February 2017

Brenda G. Valles

The school-to-prison pipeline is a booming pipeline that is the cause for alarm. Increasingly, this pipeline includes more of Chicano males, and this dynamic is reflected…

Abstract

The school-to-prison pipeline is a booming pipeline that is the cause for alarm. Increasingly, this pipeline includes more of Chicano males, and this dynamic is reflected in low rates of high school graduates going to college contrasted with the growing number of Chicanos in the juvenile justice and court systems. This study focuses on the impacts of the school-to-prison pipeline on Chicano students. Furthermore, utilizing a CRT and LatCrit framework, this study centers the experiential knowledge that Chicano students contribute to conceptualizing ways of disrupting the school-to-prison pipeline. Themes of this study include the following: (1) Chicano student experiences with the school-to-prison pipeline, (2) innovation of discipline policy and practice, and (3) effective alternative practices to a zero tolerance framework. Through this, Chicano students point to a praxis grounded in community to clear educational pathways and interrupt the school-to-prison pipeline.

Details

The School to Prison Pipeline: The Role of Culture and Discipline in School
Type: Book
ISBN: 978-1-78560-128-6

Keywords

Article
Publication date: 17 June 2022

Wei Liu, Hongyan Zhu and Wangzhen Li

The dynamic characteristics prediction and frequency-modulation of pipeline was an important work for the design of aircraft hydraulic structure.

Abstract

Purpose

The dynamic characteristics prediction and frequency-modulation of pipeline was an important work for the design of aircraft hydraulic structure.

Design/methodology/approach

A complex pipeline was deemed as a combination of several segments of straight-pipe-element (SPE). The 3D vibration equations of each SPE were established in their local coordinate system based on Timoshenko-beam model and Euler-beam model, respectively. The dynamic-stiffness-matrixes were deduced from the dispersion relation of these equations. According to the complex pipeline layout in the global coordinate system, a multi dynamic stiffness matrixes assembling (MDSMA) algorithm was carried out to establish the characteristic equations of the whole complex pipeline. The MDSMA solutions were verified to be consistent with experimental results.

Findings

The MDSMA method based on Timoshenko-Beam model was more suitable for the short span aviation pipeline and the vibration at high frequency stage (>350 Hz). The layout affected the pipeline's in-plane stiffness and out-plane stiffness, for the Z-shaped pipe, each order natural mode took place on the ZP and NP alternately. Reasonable designs of bending position and bending radius were effective means for complex pipeline frequency-modulation.

Originality/value

A new dynamic modeling method of aircraft complex pipeline was proposed to obtain the influence of pipeline layout parameters on dynamic characteristics.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 18 March 2022

Donghai Wang, Wei Sun, Zhihui Gao and Hui Li

In many cases, the external pipelines of aero-engine are subjected to random excitation. The purpose of this paper is to reduce the vibration response of the pipeline

Abstract

Purpose

In many cases, the external pipelines of aero-engine are subjected to random excitation. The purpose of this paper is to reduce the vibration response of the pipeline system effectively by adjusting the hoop layout.

Design/methodology/approach

In this paper, a spatial pipeline supported by multi-hoops is taken as the object, the methods of solution of the vibration response of the pipeline system by using pseudo excitation and hoop layouts optimization with amplitude reduction of vibration response as the goal are presented. First, the finite element model of the spatial pipeline system is presented. Then, an optimization model spatial pipeline is established. Finally, a case study is carried out to prove the rationality of the random vibration response analysis of the pipeline system. Furthermore, the proposed optimization model and genetic algorithm are applied to optimize the hoop layout.

Findings

The results show that the maximum response variance after optimization is reduced by 32.8%, which proves the rationality of the developed hoop layout optimization method.

Originality/value

The pseudo excitation method is used to solve the vibration response of aero-engine pipeline system, and the optimization of the hoop layout for aero-engine spatial pipelines under random excitation to reduce random vibration response is studied systematically.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 8
Type: Research Article
ISSN: 1748-8842

Keywords

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