scholarly journals Failure in a pipe due to defective maintenance

2021 ◽  
pp. 1-7
Author(s):  
Juan Manuel SALGADO-LÓPEZ ◽  
José Luis OJEDA-ELIZARRARAS ◽  
Francisco Ignacio LOPEZ-MONROY ◽  
Mauricio TELLO-RICO
Keyword(s):  
Energy Efficiency ◽  
Failure Analysis ◽  
Preventive Maintenance ◽  
Visual Inspection ◽  
Energy Transport ◽  
Energy Losses ◽  
Environmental Damage ◽  
Transportation Process ◽  
Corrosion Pitting ◽  
Energy Transportation

Proper maintenance of energy transport pipelines is a part of energy efficiency since energy losses during transport are reduced with good maintenance practices as well as the mechanical integrity can be known. Moreover, it reduces the risk of accidents or environmental damage. This work is an example of the experiences that must be taken into account for optimal pipeline maintenance and consisted of a failure analysis performed on a 20-inch diameter "T" connection, which plays an important role in the energy transportation process and it was found to be partially buried with exposure to rainwater. Preventive maintenance consists of visual inspection, cleaning, and coating with paint. The results indicated that the failure begun due to fatigue with origin in weld defects and the fracture grew up due to an overload, which caused the crack to grow following the region of the material with loss of thickness induced by corrosion pitting.

Investigation of Thermal Effects in Direct Driven Hydraulic System for Off-Road Machinery

2016 ◽  
Author(s):  
Niko Karlén ◽  
Tatiana Minav ◽  
Matti Pietola
Keyword(s):  
Energy Efficiency ◽  
Hydraulic System ◽  
Energy Savings ◽  
Mechanical Energy ◽  
Hydraulic Model ◽  
Energy Losses ◽  
Total Efficiency ◽  
Ambient Temperatures ◽  
Wheel Loaders ◽  
Save Energy

Several types of off-road machinery, such as industrial trucks, forklifts, excavators, mobile cranes, and wheel loaders, are set to be operated in environments which can differ considerably from each other. This sets certain limits for both the drive transmissions and working hydraulics of these machines. The ambient temperature must be taken into account when selecting the hydraulic fluid since the viscosity and density of the fluid are changing at different operating temperatures. In addition to the temperature, energy efficiency can also be a problem in off-road machinery. In most off-road machines, diesel engines are employed to produce mechanical energy. However, there are energy losses during the working process, which causes inefficiency in produced energy. For better energy efficiency, hybridization in off-road machinery is an effective method to decrease fuel consumption and increase energy savings. One of the possible methods to save energy with hybrids is energy regeneration. However, it means that the basic hydraulic system inside off-road machinery needs to be modified. One solution for this is to utilize zonal or decentralized approach by means of direct driven hydraulic (DDH) system. This paper aims to investigate a DDH system for off-road machinery by means of modelling and analyzing the effect of the temperature. In the direct-driven hydraulic system, the actuator is controlled directly by the hydraulic pump which is operated by the electric motor. Specifically, it is a valveless closed-loop hydraulic system. Thus, there will be no energy losses caused by the valves, and the total efficiency is assumed to be significantly higher. In order to examine the DDH system, a thermo-hydraulic model was created. Additionally, a thermal camera was utilized in order to illustrate the temperature changes in the components of the DDH system. To reproduce the action of the system in different circumstances DDH system was run at different ambient temperatures, and the component temperatures in the system were measured and saved for the analysis. The thermo hydraulic model was proven capable to follow the general trend of heating up.

scholarly journals Failure Analysis of fractured Fixing Bolts of a Mobile Elevating Work Platform using Finite Element Methods

2019 ◽  
Author(s):  
DongHoon Choi ◽  
Jae-Hoon Kim
Keyword(s):  
Finite Element ◽  
Chemical Composition ◽  
Chemical Analysis ◽  
Failure Analysis ◽  
Visual Inspection ◽  
Standard Procedure ◽  
Fatigue Analysis ◽  
Certification Authority ◽  
Element Analysis ◽  
Safety Certification

Mobile elevating work platforms (MEWPs) consist of a work platform, extending structure, and chassis, and are used to move persons to working positions. MEWPs are useful but are composed of pieces of equipment, and accidents do occur owing to equipment defects. Among these defects, accidents caused by the fracture of bolts fixed to the extension structure and swing system are increasing. This paper presents a failure analysis of the fixing bolts of MEWP. Standard procedure for failure analysis was employed in this investigation. Visual inspection, chemical analysis, tensile strength measurement, and finite element analysis (FEA) were used to analyze the failure of the fixing bolts. Using this failure analysis approach, we found the root cause of failure and proposed a means for solving this type of failure in the future. First, the chemical composition of the fixing bolt is obtained by a spectroscopy chemical analysis method, which determined that the chemical composition matched the required standard. The tensile test showed that the tensile and yield strengths were within the required capacity. The stress analysis was carried out at five different boom angles, and it was determined that the fixing bolt of MEWP can withstand the loads at all the boom angles. The outcomes of the fatigue analysis revealed that the fixing bolt fails before reaching the design requirements. The results of the fatigue analysis showed primarily that the failure of the fixing bolt was due to fatigue. A visual inspection of the fractured section of the fixing bolt also confirmed the fatigue failure. We propose a method to prevent failure of the fixing bolt of the MEWP from four different standpoints: the manufacturer, safety certification authority, safety inspection agency, and owner.

Failure Analysis of Railroad Components

2021 ◽  
pp. 754-777
Author(s):  
Hans Iwand ◽  
Joel Hassebrock
Keyword(s):  
Fatigue Life ◽  
Failure Analysis ◽  
Safety Factor ◽  
Case Histories ◽  
Manufacturing Defects ◽  
Railroad Industry ◽  
Primary Mode ◽  
Mode Of Failure ◽  
Engineering Environment ◽  
Corrosion Pitting

Abstract Because of the tough engineering environment of the railroad industry, fatigue is a primary mode of failure. The increased competitiveness in the industry has led to increased loads, reducing the safety factor with respect to fatigue life. Therefore, the existence of corrosion pitting and manufacturing defects has become more important. This article presents case histories that are intended as an overview of the unique types of failures encountered in the freight railroad industry. The discussion covers failures of axle journals, bearings, wheels, couplers, rails and rail welds, and track equipment.

Performance of Oil Separator According to the Depth of the Outlet Tube

2015 ◽  
Author(s):  
Seongil Jang ◽  
Joon Ahn ◽  
Si Hyung Lim
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Pressure Drop ◽  
Separation Efficiency ◽  
Lubricating Oil ◽  
Tube Length ◽  
Working Fluid ◽  
Energy Losses ◽  
Refrigeration System ◽  
Outlet Tube

Recent years have witnessed a growing concern over saving energy because of global warming issues and energy price hikes caused by increased oil prices. The need to improve energy efficiency to reduce energy consumption has been raised. Refrigeration systems are also expected to have their energy efficiency improved. A refrigeration system’s the compressor uses lubricating oil. Lubricating oil, along with refrigerant, circulates in a refrigeration system. During this process, the pressure drop increases, and the heat transfer coefficient decreases. Moreover, insufficient lubricant may incur a decrease in performance and damage to a compressor. Therefore, an oil separator is used to separate the lubricant and return it to the compressor. Since an oil separator causes an additional pressure drop, energy consumption should be decreased by increasing the oil separator’s separation efficiency and decreasing the pressure drop. The recent increase in development of large-scale buildings such as skyscrapers and large supermarkets has also increased the demand for large refrigeration machines. At the same time, refrigeration piping is becoming longer, and refrigerant must circulate up to the highest points. A high-pressure head and long piping configuration inevitably increase the quantity of lubricant left on the pipe wall, which in turn increases the loss of lubricants. The increased length and fall height for lubricants to circulate with refrigerant increase the related energy loss. In order to use a compressor in a high-head long-piping refrigeration system, the separation efficiency of the oil separator must be improved. Doing so will also reduce energy losses. Even with an improved separation efficiency, however, an increased pressure drop means additional energy losses. Thus, an oil separator with high separation efficiency and low pressure drop should be designed. So using the Numerical analysis, designed a new oil separator. A series of numerical simulation has been carried out to study peformance of a cyclone type oil separator, which is designed for the compressor of a refrigeration system. Working fluid is R22, which is a typical refrigerant, and mineral oil droplet is supplied. Depending on the outlet tube length, separation efficiency varies from 98.74 to 99.25%. Considering both of the separation efficiency, outlet tube length of the separator has been designed as 158 mm and oil separator length is 310mm.

scholarly journals An Automatic Road Distress Visual Inspection System Using an Onboard In-Car Camera

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Thitirat Siriborvornratanakul
Keyword(s):  
Preventive Maintenance ◽  
Visual Inspection ◽  
Current System ◽  
Ease Of Use ◽  
Capital City ◽  
Inspection System ◽  
Maintenance Strategy ◽  
Road Maintenance ◽  
Proof Of Concept ◽  
Road Inspection

Speaking of road maintenance, the preventive maintenance strategy is preferable for most governments. Many governments possess special vehicles that can accurately detect and classify many types of road distresses. By running these vehicles frequently, small road distresses will be detected before growing into the big ones. However, because running these huge and expensive vehicles is not easy, in practical, it usually ends up with infrequent road inspection regardless of having automatic road inspection vehicles. In this paper, we focus on investigating and developing an automatic and nondestructive visual inspection system whose setup and usage are designed by considering the context of drivers, driving styles, and road conditions in Bangkok, the capital city of Thailand. Our proposal includes a workflow diagram of a vision-based road inspection system that is capable of detecting, classifying, tracking, measuring, and pricing road distresses. As for the proof-of-concept, our current system focuses on detecting one specific type of road distresses called pothole, using only one onboard in-car camera. Experimental results reveal that the context of Bangkok introduces many nontrivial challenges for vision-based analysis systems where maintaining both accuracy and ease of use altogether may not be easy.

Energy Efficiency Evaluation in a Pulp and Paper Industry in South Africa - A Case Study

2017 ◽  
Vol 32 ◽  
pp. 155-168
Author(s):  
Samuel A.O. Ilupeju ◽  
Hilton Maverengo ◽  
Freddie L. Inambao ◽  
Ntumba Marc Alain Mutombo
Keyword(s):  
South Africa ◽  
Energy Efficiency ◽  
Paper Industry ◽  
Significant Proportion ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Energy Utilization ◽  
Energy Losses ◽  
Base Case

Power consumption is becoming more expensive by the day. This is not far from the fact that power generation is facing a lot of challenges coupled with increasing demand. Industrial sector power demand shares a significant proportion of this generated power. It is therefore a necessary task to manage well industrial energy use through appropriate energy efficiency methods practice so as to minimise energy losses. In this study energy efficiency opportunities in pulp and paper (P&P) mill are identified and the saving potential is then quantified. An energy flow model with the help of an energy audit are used to quantify energy supply, generation, conversion and end use thereby exposing areas of energy losses of the mill. This analysis will serve as an eye opener to future and current P&P making operations in South Africa, and as a base case for stimulating changes toward more efficient energy utilization in the pulp and paper industry. Quite a reasonable energy losses avenues were identified, audited and options of improvements suggested. The results proved that quite a sensible amount of energy is lost in the P&P case study and a near future look into the opportunities and barriers have been noted.

Metallurgy Selection of Tubing in Sucker Rod Pump Wells Plagued with Pitting and Abrasion Issues

2021 ◽  
Author(s):  
Rishabh Uniyal ◽  
Rajeev Bansal ◽  
Suman Kumar Jaruhar ◽  
Sudipta Biswas ◽  
Sagun Devshali ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Primary Objective ◽  
General Corrosion ◽  
Uniform Corrosion ◽  
Mechanical Wear ◽  
Root Cause ◽  
Sucker Rod ◽  
Sucker Rod Pump ◽  
Cause Of Failure ◽  
Corrosion Pitting

Abstract Analysis of tubing failure of SRP wells with respect to uniform corrosion, pitting and mechanical abrasion has been carried out. The primary objective includes the identification of root cause of failure and suggesting alternate metallurgy. Many wells in an onshore field in ONGC were facing the acute problem of general corrosion, pitting and rod-tubing wear. The methodology for carrying out the study consists of a Failure Analysis of a retrieved sample of the failed tubing from one of the affected wells. This included a thorough visual inspection, Scanning Electron Microscope analysis and X-Ray Diffraction analysis. The results of these tests were backed up by software simulation in Honeywell Predict. Metallurgy selection involved multiple exhaustive simulation runs in Honeywell Software Socrates which was corroborated by relevant oilfield standards as well as literature available on the subject matter. Based on the failure analysis and simulation runs, it was concluded that besides the issue of uniform corrosion and pitting, many of the affected wells are also facing the problem of tubing failures due to abrasion and mechanical wear. It is pertinent to note that the major contributor of the frequent tubing failures in the candidate wells selected for the study were pitting and corrosion. Nevertheless, Abrasion always remains a key threat to the tubing string integrity in rod-pump wells. Therefore, the existing tubing metallurgy of N-80 grade Carbon Steel was deemed inadequate in the absence of reliable corrosion inhibitor continuous dosing facilities. A tubing metallurgy that takes care of both pitting corrosion as well as abrasion and mechanical wear was sought. UNS 41426/41427 or the modified version of 13 Chrome, commercia lly known as Super Martensitic 13 Chrome, are available in 95 ksi and 110 ksi grades. These grades have a maximum hardness of 28-32 HRC which is substantially high compared to L-80 13 Cr (maximum 23 HRC). Also, as this alloy has 4-6% Nickel, it provides added protection against uniform corrosion as well as pitting and hence was recommended. The paper specifically analyses tubing failure in Sucker rod-pump wells due to corrosion, pitting and abrasion. After exploring various viable options, adequate tubing metallurgy has been recommended that should take care of corrosion, pitting as well as mechanical wear problems.

Сomparative analysis of the calculation results of infiltration losses on the example of a residential building in Moscow

2019 ◽  
Vol 1 (2) ◽  
pp. 63-72
Author(s):  
Ju. S. Gribach ◽  
D. S. Gribach ◽  
O. I. Poddaeva
Keyword(s):  
Energy Efficiency ◽  
Construction Industry ◽  
Experimental Studies ◽  
Energy Losses ◽  
Construction Sites ◽  
Technical Literature ◽  
Regulatory Documents ◽  
Calculation Results ◽  
The Russian Federation ◽  
Using Data

Today, the problem of energy efficiency is one of the leading positions in world politics. On the territory of the Russian Federation, a sufficient number of regulatory documents in the construction industry have been developed and put into effect, which regulate the activities of designers and builders in the field of energy efficiency, including in matters of energy losses. However, today this direction is not sufficiently developed: more than 10 % is spent on air heating during infiltration, while the process itself requires the most detailed study. On the basis of scientific and technical literature, the staff of the National Research Moscow State University of Civil Engineering concluded that there is a dependence of air infiltration on the distribution of the velocity of wind flows along the building facades. It was also determined that the calculation of infiltration losses on the methods available to date overstates the results, which leads to large economic losses during construction. In this regard, a study of infiltration losses was carried out using data obtained from experimental studies of wind effects on the construction site. The article presents a brief methodology for carrying out this study, a description of the process of the experiment, as well as a comparison of the data obtained in the calculation according to SP 50.13330.2012, GOST R 55656-2012 and GOST R 55656-2012 with the results of an experimental study.Introduction:the regulatory documents used in the construction industry on the territory of the Russian Federation that regulate the activities of designers and builders in the field of energy efficiency, including in matters of energy losses, are described. An analysis of the technical literature regarding the subject under study is also presented, including issues related to heat losses and infiltration.Methods:methods for calculating infiltration losses according to SP 50.13330.2012, GOST R 55656-2013 and GOST R 55656-2013 are described using data on the aerodynamic characteristics of buildings obtained in the course of experimental studies of wind impact on buildings. A brief algorithm for performing physical modeling of air flow to construction sites, which was developed by the staff of the Educational, Scientific and Production Laboratory for aerodynamic and aeroacoustic testing of building structures of the National Research University MGSU, is presented.Results and discussions:the approbation of this research methodology is presented, and a comparative graph of the calculation results for all three methods is given on the example of a residential complex under construction in Moscow.Conclusion:the conclusion is made about the need to conduct experimental studies of wind impact on construction sites in order to obtain more accurate results of the calculation of infiltration.

Methodology for analyzing reliability of the equipment of electric locomotives 2ES10

2021 ◽  
pp. 28-39
Author(s):  
A. A. Vorobyov ◽  
◽  
R. S. Smetanin ◽  
Keyword(s):  
Preventive Maintenance ◽  
Rolling Stock ◽  
Careful Monitoring ◽  
Traction Drive ◽  
Pareto Analysis ◽  
Traction Motors ◽  
Transportation Process ◽  
Equipment Failures ◽  
Operational Failures ◽  
Repair Cycle

The article deals with the analysis of reliability of the equipment of 2ES10 electric locomotives with asynchronous traction motors as a complex system and equipment failures that are often encountered during operation. All submitted failures are divided by type of equipment. Based on the Pareto analysis, the main limiting units of these electric locomotives with the lowest reliability are determined. Based on the Pareto analysis, the frequently failing elements of the main limiting components are determined, which are the mechanical part, wheel pairs, brake equipment, traction drive and traction motors. These elements have a major impact on the safety of train traffic and therefore it is extremely important to constantly assess the condition of these elements. Attention is focused on the analysis of risks associated with the possible formation of operational failures, the system of planned preventive maintenance, methods and tools for assessing reliability, incorrect regulatory and documentation support and fixing operational defects, and their subsequent processing. Such a study makes it possible to improve the safety of the transportation process by careful monitoring of the most vulnerable areas of the rolling stock. This reveals the prefailure state before it occurs. The results of the study can be used as a basis for adjusting the current structure of the repair cycle in terms of reducing inter-repair runs.

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