scholarly journals PENENTUAN TEMPERATUR OPERASIONAL “ROD HANGER TUBE HEATER” AGAR MENCAPAI UMUR OPERASI DESAIN

2016 ◽  
Vol 10 (3) ◽  
pp. 211-218
Author(s):  
Hadi Sunandrio
Keyword(s):  
Creep Test ◽  
Master Curve ◽  
Best Practice ◽  
Life Time ◽  
Time To Rupture ◽  
Mean Time

Rod Hanger Tube Heater yang sudah beroperasi sekitar ± 7 bulan akan tetapibelum dilengkapi dengan best practice berapa lama MTBF (Mean Time BetweenFailure) atau Life Time nya. Oleh karena itu dibutuhkan pengujian untukmengetahui berapa sebenarnya Life Time dari Rod Hanger, yang nantinya akanmenjadi acuan MTBF dari Rod Hanger tersebut. Pada tulisan ini akan disajikansuatu hasil pengujian mulur (creep test) dari Rod Hanger, yang kemudiandiekstrapolasi sehingga akan menghasilkan grafik LMP vs tegangan, yangmerupakan kombinasi tiga parameter yaitu waktu (time to rupture), logaritmategangan dan suhu operasi menjadi satu kurva yang disebut Kurva MasterLarson-Miller Parameter (LMP Master Curve). Selanjutnya parameter ini dapatdigunakan untuk menghitung umur pakai Rod Hanger yang dioperasikan padasuhu tinggi, dengan menggunakan persamaan Larson-Miller Parameter (LMP)

Creep Assessment of Large Size High Temperature Components Using Small Creep Test Specimens

2016 ◽  
Author(s):  
Balhassn S. M. Ali
Keyword(s):  
High Temperature ◽  
Creep Test ◽  
Nuclear Power ◽  
Power Plants ◽  
Elevated Temperatures ◽  
Life Time ◽  
Safe Operation ◽  
Large Size ◽  
Testing Techniques ◽  
High Temperature Components

Most of the large components in the thermal, traditional and nuclear power plants such as pressurized vessels and pipes are operating at elevated temperatures. These temperatures and stress are high enough for creep to occur. For variety of reasons many of these power plants are now operating beyond their design life time. It is -known fact that as the high temperature components aged the failure rate normally increases as a result of their time dependent material damage. Further running of these components may become un-safe and dangerous in some cases. Therefore, creep assessment of the high temperature components of these plants is essential for their safe operation. Mainly for economic reasons these components have to be creep assessed as they are in service. However, assessing the creep strength for these high temperature components as they are in service, it can be challenging task, especially when these components are operating under extremely high temperature and/or stress. This paper introduces newly invented, small creep test specimens techniques. These new small types of specimens can be used to assess the remaining life times for the high temperature components, using only small material samples. These small material samples can be removed from the operating components surface, without affecting their safe operation. Two of the high temperature materials are used to validate the new testing techniques.

scholarly journals One law to rule them all: Stretched exponential master curve of capacity fade for Li-ion batteries

2019 ◽  
Author(s):  
Eduardo Cuervo-Reyes ◽  
Reto Flueckiger
Keyword(s):  
Master Curve ◽  
Life Time ◽  
Cell Types ◽  
Li Ion Batteries ◽  
Stretched Exponential ◽  
Temperature State ◽  
Cell Type Specific ◽  
Li Ion ◽  
Common Behaviour ◽  
Standardised Testing

Li-ion batteries gradually lose their capacity with time and use; therefore, ageing forecasts are key to designs of battery powered systems. So far, cell-type-specific studies without standardised testing practices have lead to a variety of ageing models in which generality, simplicity, and accuracy seem exclusive. Previous studies hint to an interplay of multiple mechanisms leading to capacity loss, which depend on cell chemistry and are affected by temperature, state of charge, and cycling rate. Here we show that, despite this complexity, the time dependence of the actual capacity follows a unique master curve, for several cell types aged under various different conditions. We discuss the statistical origin of this common behaviour, and the testing practice required for the characterisation of a model. The master curve is a stretched exponential that describes many other phenomena in nature and is theoretically justified within a diffusion-to-traps depletion model. These findings provide a simple and broadly applicable framework for accurate life-time predictions.

scholarly journals Maintainability of electronic instruments for meteorological applications

MAUSAM ◽  
2021 ◽  
Vol 43 (4) ◽  
pp. 349-352
Author(s):  
N. SEN ROY
Keyword(s):  
Support System ◽  
Life Time ◽  
Important Application ◽  
Digital Systems ◽  
Terminal Phase ◽  
Failure Behaviour ◽  
Production Phase ◽  
Trouble Shooting ◽  
Recent Origin ◽  
Mean Time

The concept of Maintainability (M) of electronic instruments. though of recent origin, has Important application for meteorological equipments, which have special requirements. M is defined quantitatively in terms of mean time to repair and is Influenced by the failure behaviour of an equipment. An equipment goes through teething trouble, useful and terminal phase. Much of  maintainability can be incorporated during design and production phase. This reduces the effective overall cost of the equipment during its life time. Special maintenance support system is necessary for meteorological Instruments. Some recent tools for trouble shooting in digital systems have been discussed.

Fitness-for-Service Analysis of Skelp-End Welds in Spiral Pipes

2012 ◽  
Author(s):  
Ming Liu ◽  
Yong-Yi Wang ◽  
Steve Rapp
Keyword(s):  
Quality Control ◽  
Best Practice ◽  
Large Diameter ◽  
Life Time ◽  
Companion Paper ◽  
Control Measures ◽  
Loading Conditions ◽  
Integrity Risk ◽  
Static And Cyclic Loading ◽  
Extensive Fitness

For large diameter spiral pipes, there can be one skelp-end weld (SEW) in every 5–7 joints of pipes. The industry acceptance of SEWs is uneven although API 5L permits SEWs in finished pipes. A joint industry project (JIP) [1] was formed to develop uniformly acceptable inspection and test plans (ITPs) for SEWs. The development was conducted through two parallel processes: (1) fitness-for-service analysis of the SEWs under a variety of loading conditions expected in their life time and (2) consensus building based on the best practice and quality control protocols. This paper details the fitness-for-service analysis of SEWs. A companion paper provides a summary of the recommended ITPs developed in the JIP [2]. In the fitness-for-service analysis, the SEWs were subjected to a variety of loading conditions covering construction, commissioning, and normal service with and without internal pressure. For in-service loading, both static and cyclic loading was considered. The extensive fitness-for-service analysis demonstrated that there is no inherent integrity risk associated with the SEWs when these welds are manufactured, tested, and inspected using generally accepted quality control measures applied to helical seam welds. Additional inspection and quality control for coil end properties and T-joints are recommended in the companion paper.

STYLE: Project Overview

2010 ◽  
Author(s):  
Tomas Nicak ◽  
Elisabeth Keim
Keyword(s):  
Time Management ◽  
Nuclear Power ◽  
Power Plants ◽  
Large Scale ◽  
Best Practice ◽  
Structural Integrity ◽  
Life Time ◽  
Assessment Tools ◽  
Integrity Assessment ◽  
University Of Bristol

The purpose of this paper is to introduce a new EUROATOM project focusing on the structural integrity assessment of reactor coolant pressure boundary components (RCPB) relevant to ageing and life time management. The project started in January 2010 and will last 4 years. The project is coordinated by AREVA NP GmbH with 20 partner organizations from Europe, one collaborator from USA and one collaborator from Russia: AEKI, Hungary; AREVA NP GmbH, Germany (coordination, WP2 leader); AREVA NP SAS, France; Bay Zoltan, Hungary; British Energy Generation Ltd., UK (WP7 leader); CEA, France (WP1 leader); EDF, France; IdS, France; INR, Romania; IWM, Germany; JRC, Netherlands (WP4 leader); NRI, Czech Republik; NRG, Netherlands; SCK-CEN, Belgium; Serco Assurance Technical Services, UK (WP3 and WP5 leader); University of Bristol, UK; University of Manchester, UK; Technatom, Spain; Vattenfall, Sweden (WP6 leader); VTT, Finland. Within STYLE (Structural integrity for lifetime management – non-RPV components) realistic failure models for some of the key components will be identified. The range of assessment tools considered will include those for assessment of component failure by advanced fracture mechanics analyses validated on small and large scale experiments, quantification of weld residual stresses by numerical analysis and by measurements, stress corrosion crack initiation/ growth effects and assessment of RCPB components (excluding the reactor pressure vessel) under dynamic and seismic loading. Based on theoretical and experimental results, performance assessment and further development of simplified engineering assessment methods (EAM) will be carried out considering both deterministic and probabilistic approaches. Integrity assessment case studies and large scale demonstration experiments will be performed on Mock-ups of safety-relevant components. These will include a repair weld in an aged butt-welded austenitic pipe, a dissimilar narrow gap TIG weld (following the EPR design) and a cladded ferritic pipe. Moreover experiments on specimens and feature test pieces will be carried out to support the large scale Mock-up analyses. The end product of the project (“STYLE TOOLS”) will comprise best practice guidelines on the use of advanced tools, on improvement and qualification of EAM as a part of European Leak-before-break (LBB) procedures and on life time management of the integrity of RCPB components in European nuclear power plants. The project will interact with the European Network of Excellence NULIFE.

scholarly journals Multistage Creep Test of Inada Granite and Estimation of Long-term Life Time under Confining Pressure.

2000 ◽  
Vol 116 (2) ◽  
pp. 91-96 ◽  
Author(s):  
Tsutomu YAMAGUCHI ◽  
Seisuke OKUBO ◽  
Enrico MARANINI ◽  
Takashi NARITA
Keyword(s):  
Creep Test ◽  
Life Time ◽  
Confining Pressure

An Application of a Generalized Life Cycle Cost Model to a Typical Pump From Industry

2009 ◽  
Author(s):  
L. Y. Waghmode ◽  
A. D. Sahasrabudhe
Keyword(s):  
Life Cycle ◽  
Life Span ◽  
Life Cycle Cost ◽  
Cost Model ◽  
Life Time ◽  
Maintenance Cost ◽  
Repairable System ◽  
Repairable Systems ◽  
Generalized Model ◽  
Mean Time

The objective of this paper is to develop a methodology for effective implementation of life cycle costing (LCC) in design and procurement of repairable and non-repairable products. For this purpose, a generalized model for LCC of repairable and non-repairable products has been proposed. The equations of cost components of the proposed generalized model have been formulated for repairable systems based on the reliability and maintainability aspects to enable the life-time cost conscious design of such systems. The repairable systems typically have a life span of 10 to 20 years and experience multiple failures over their life span. The life cycle cost of a repairable system is significantly influenced by its reliability and maintainability. The life time energy and/or maintenance cost often dominate LCC for most of the repairable systems. Under the condition of constant failure rate the repairable system reliability is characterized by mean time between failures (MTBF) and maintainability by mean time to repair (MTTR). A higher value of MTBF and lower value of MTTR results into lower life cycle cost and therefore a due consideration to these factors is essential while designing repairable systems. The generalized LCC model presented in this paper will assist the designers to compare the life cycle cost of their different design alternatives at product design phase wherein most of the life cycle costs are committed. The developed generalized LCC model is applied to a typical repairable system, a pump from industry and the results obtained are presented.

SEM and Auger microanalysis studies of Cu-Be dynode surfaces at each activation condition

1978 ◽  
Vol 36 (1) ◽  
pp. 524-525
Author(s):  
T. Koshikawa ◽  
Y. Fujii ◽  
E. Sugata ◽  
F. Kanematsu
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Life Time ◽  
Activation Process ◽  
Beam Diameter ◽  
Activation Temperature ◽  
Electron Multiplier ◽  
Activation Condition ◽  
Activation Conditions

The Cu-Be alloys are widely used as the electron multiplier dynodes after the adequate activation process. But the structures and compositions of the elements on the activated surfaces were not studied clearly. The Cu-Be alloys are heated in the oxygen atmosphere in the usual activation techniques. The activation conditions, e.g. temperature and O2 pressure, affect strongly the secondary electron yield and life time of dynodes.In the present paper, the activated Cu-Be dynode surfaces at each condition are investigated with Scanning Auger Microanalyzer (SAM) (primary beam diameter: 3μmϕ) and SEM. The commercial Cu-Be(2%) alloys were polished with Cr2O3 powder, rinsed in the distilled water and set in the vacuum furnance.Two typical activation condition, i.e. activation temperature 730°C and 810°C in 5x10-3 Torr O2 pressure were chosen since the formation mechanism of the BeO film on the Cu-Be alloys was guessed to be very different at each temperature from the results of the secondary electron emission measurements.

Meeting the Best Practice for Hearing Aid Verification in Children: Challenges and Future Directions

2019 ◽  
Vol 28 (4) ◽  
pp. 877-894
Author(s):  
Nur Azyani Amri ◽  
Tian Kar Quar ◽  
Foong Yen Chong
Keyword(s):  
Clinical Practice ◽  
Hearing Aids ◽  
Best Practice ◽  
Hearing Aid ◽  
Evidence Based ◽  
Future Directions ◽  
Major Barrier ◽  
Klang Valley ◽  
Age Range ◽  
Fitting Hearing Aids

Purpose This study examined the current pediatric amplification practice with an emphasis on hearing aid verification using probe microphone measurement (PMM), among audiologists in Klang Valley, Malaysia. Frequency of practice, access to PMM system, practiced protocols, barriers, and perception toward the benefits of PMM were identified through a survey. Method A questionnaire was distributed to and filled in by the audiologists who provided pediatric amplification service in Klang Valley, Malaysia. One hundred eight ( N = 108) audiologists, composed of 90.3% women and 9.7% men (age range: 23–48 years), participated in the survey. Results PMM was not a clinical routine practiced by a majority of the audiologists, despite its recognition as the best clinical practice that should be incorporated into protocols for fitting hearing aids in children. Variations in practice existed warranting further steps to improve the current practice for children with hearing impairment. The lack of access to PMM equipment was 1 major barrier for the audiologists to practice real-ear verification. Practitioners' characteristics such as time constraints, low confidence, and knowledge levels were also identified as barriers that impede the uptake of the evidence-based practice. Conclusions The implementation of PMM in clinical practice remains a challenge to the audiology profession. A knowledge-transfer approach that takes into consideration the barriers and involves effective collaboration or engagement between the knowledge providers and potential stakeholders is required to promote the clinical application of evidence-based best practice.

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