Recent Completed Project on Metallography, Accelerated Rupture Testing and Remaining Life Assessment of Superheater & Reheater Tubes

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ETD is pleased to announce the successful recent completion of a metallography, accelerated rupture testing and remaining life assessment project of superheater & reheater tubes.

It is reported by the client that they had hired a sub-contractor to perform accelerated rupture testing and remnant life assessment work for 1 superheater and 1 reheater tubes (of T91 materials). This contractor had completed the creep test and RLA based on an iso-thermal basis with reference to Manson-Haferd curve. Recently, the client hired a second contractor to do the same job. This second contractor had done the creep test and RLA based on an iso-stress basis. The actual service stress in this case is relatively low. The client had found that the results from these two contractors differed greatly; the results of second contractor showed unrealistically high remaining life and they did not consider progressive wastage.

Therefore, ETD was approached with a request to perform the same work (accelerated rupture testing and RLA) again for these two coal-fired tubes to provide an estimate for the remaining life of the components.

The scope of the work carried out included the following tasks:

i.  Metallography - Metallography of two tube samples were carried out to establish the creep damage (i.e. creep cavitation & microstructure degradation) levels. The microstructure and any degradation characterised using damage classification for creep damage of the relevant materials. Specific scope in this task included:

  • Visual examination of the tube samples including internal and external appearance;

  • Assessment of condition of internal and external surfaces including identification of inclusions/ contaminations, scale/ deposits, welding defects etc (if any exists) and obtain photos of evidence;

  • Dimensional examination - OD measurement at 12-6 and 3-9 O’clock positions at fixed length intervals throughout the entire tube length.

  • Tube wall thickness measurements for all aforementioned clock positions.

  • Metallographic examination of the tube samples using optical microscopy to assess the condition of internal and external surfaces, to identify phase changes in microstructure / material degradation/ precipitations and also to identify the damage mechanism(s);

  • Estimation of tube operating temperature based on measurements of steam-side oxide thickness;

  • Hardness testing and evaluation to determine the equivalent tensile strength values (using published hardness/ UTS correlation tables) to assess the mechanical strength or softening of the materials.

ii.  Accelerated Stress Rupture Testing - A programme of isothermal rupture testing was then performed comprising three specimens from each of the two tube samples to be tested. The tests were performed at conditions designed to achieve target durations of 500, 1000 and 3000 hours as proposed by ETD. After reviewing the design and operating parameters, the test conditions (i.e. temperature, stress etc) was selected by ETD based on previous experience and reference database to give failures at the above number of hours.

All these tests will be conducted by ETD’s collaborative accredited laboratory in Europe and according to the international and ECCC specifications.

iii.  Analysis of Creep Test Results and Remaining Life Calculations - The results from the above rupture testing programme were compared with standard data for the relevant steel grade to establish where, within the upper and lower bounds, the material creep properties lie. Hence an equation describing the actual creep strength of the ex-service material being modelled. This equation was then used to estimate the creep life at the service conditions.

Provided that the as-installed tube wall thickness and service hours to date are known, then the corrosion rate (wall thinning rate) can be calculated using the thickness measurements from the first task. This corrosion rate was used to determine the combined effect of creep and corrosion on the component remaining life at the effective operating temperature estimated in the first task.

A final report, detailing the findings of the tasks undertaken, was issued for comments by the client. It will include photographic records from the metallographic study and provide details of the remaining life estimate based on accelerated rupture testing. Any possible causes for concern will be highlighted. The influence of material degradation and other microstructural changes were also discussed in this report.

For more information about our life assessment services please click here.

Recent Completed Project on Condition and Life Assessment Study of Radiant Tubes

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ETD is pleased to announce the triumphant completion concerning matters on Condition and life assessment of radiant tubes for a Petrochemical Plant in Asia.

The client requested a quotation on vertically hanged Radiant tubes which have been in operation since Jan-2014. Significant permanent bowing due to unbalanced counterweight effect during first 2 years in operation was observed. Sudden temperature drop was noticed during instrument failure in June-2017. During the 4 years operation period, no tube rupture, no tube bulging, no dimensional difference or growth on diameter was observed.

Due to high temperature operation of radiant tubes, losing strength / metallurgical property due to carburization, oxidization, micro and macro cracks, grain issues, precipitation, creep, etc. was expected.

The scope of the work to be carried out included:

  • Visual and dimensional examination of the tube samples including internal and external appearance;

  • Assessment of condition of internal and external surfaces including identification of inclusions/ contaminations, welding defects etc (if any existed);

  • Chemical analysis of base material to determine the chemical composition of the tube material to establish actual material constituents;

  • Metallographic examination of the tube samples using optical and scanning electron microscopy to assess the condition of internal and external surfaces, to identify phase changes in microstructure / material degradation/ precipitations and also to identify the damage mechanism(s);

  • Further examination using Scanning Electron Microscope (SEM) to confirm any damage or material degradation;

  • Hardness testing and evaluation to determine the equivalent tensile strength values (using published hardness/ UTS correlation tables) to assess the mechanical strength or softening of the materials;

  • Basic review of design drawings, design & operating parameters, previous failure and maintenance history;

  • Perform condition assessment and remaining life assessment based on the findings of above investigations.

  • Preparation of a report covering results of all above investigations, results of life assessment and recommendations for any suitable actions to be taken for safe operation of the component.

The client required a comprehensive report covering all the metallurgical analysis to evaluate the condition and life assessment of the tubes and to characterise any observable damage.

For more information on our Life Assessment services please click here.

Recently Obtained Project Best Practices Guidelines for the Management of Pressure Parts in a Power Plant

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ETD is pleased to announce another triumphant achievement with guidelines for the Management of Pressure Parts in a Power Plant for a North African based plant.

The client has a program to develop a best practice manual for the management of pressure parts in a power plant. The thermal power plant is comprised of many high temperature and high-pressure components that are a critical part of the power generating cycle. These systems are susceptible to damage if not operated and maintained properly. Failure of these components is usually very catastrophic and could pose a risk to human life as well as incurring major downtime of a facility and associated costs of lost production. In most jurisdictions these systems are governed by regulatory bodies in order to ensure that they are maintained to a standard.

As ETD have carried out various practical review and survey type projects on risk assessment, condition assessment, life assessment and cost analysis studies including review of clients’ data on cost issues, risk events, maintenance programs, reliability and availability of plants, fleet wise comparison/benchmarking of plant performance for European, USA and Asian utilities, etc. Therefore ETD were asked to prepare a best practices document that identifies various pressure components in a boiler/ HRSG, describes the damage that can occur to them both under base-load and flexible operating conditions, the existing inspection and monitoring techniques, the development of new and more recent innovative techniques, repair practices and strategies and how to use all of these techniques to keep pressure parts in good condition and operate a power plant efficiently and at an optimum cost. This document included a management framework to ensure that all parts are being operated and maintained according to established standards in the industry and meet all the regulatory requirements. ETD have also carried out comprehensive reviews of related areas such as ‘on-line monitoring tools’, ‘developments in risk-based maintenance programs and inspection techniques’, ‘guidelines for CCGT/HRSG lifing and risk-based approaches’, ‘plant cycling (both conventional and CCGTs/ HRSGs)’, damage due to cyclic operation and risk-based inspection, power plant component replacement strategies and technical and financial risks, etc. Through its Group Sponsored Projects (GSPs) ETD has developed new and more sophisticated techniques for power plant inspection and these have included the development of the portable Scanning Force Microscope (SFM), Electrical Discharge Sampling Equipment (EDSE) - a spark erosion device for ‘boat sampling’, and its precision portable hardness tester known as the ‘Smart Sleeve’.

The document will explain the different challenges with respect to fired and non-fired boilers and describe the importance of burner adjustment to avoid flame impingement. It will cover the degradation mechanisms affecting the materials and the degradation rate. The understanding of these factors can lead to appropriate re-inspection intervals and to the establishment of effective inspection methods.

Both time-dependent and time-independent degradation mechanisms will be discussed. Waterside and fireside corrosion, flow assisted corrosion, the performance of different alloys in boilers and steam pipework, preservation while off-line, why when and how to chemically clean pressure parts, inspection, testing and record keeping procedures, keeping the steam turbine and condensers in good order, feed heaters, boiler feed pumps boiler chemistry and blowdown, steam blowing, efficiency checks, pressure tests will be discussed. Alternative methods to hydro testing, such as detailed NDE using new state-of-the-art NDE techniques, will be discussed to help limit the damage to pressure components in old plants. In terms of component preservation both dry and wet preservation techniques for long and short-term preservation will be discussed and guidelines provided.

The maintenance philosophy/ strategy should be based on the belief that it is possible to avoid unwanted equipment failures and unnecessary maintenance activities through appropriate application of various techniques supported by proven processes and procedures carried out by well-managed and competent personnel. To ensure maintenance management can achieve the business objectives such as plant availability and reliability targets, maintenance performance needs to be reported and monitored. This would then be used as input for initiating the improvement cycle. This improvement program will trigger revision of the maintenance strategies and/or change in the way utilities operate the plant. This is performed continuously to ensure that any operator can deliver what is expected by the owner.

The outcome of this project will be a manual for the management of pressure parts of power plant. This manual will offer a practical guide as to how the integrity of boiler / HRSG pressure parts is managed with emphasis on the best practices.

This study will help the participants to understand how a successful pressure part management program can deliver benefits related to better informed strategic decisions, increased operational efficiency, safety and integrity of the equipment.

For more information on our guidelines & reports, please click here.

Recently Obtained Project on Best Practices Guidelines for the Operation and Maintenance of Steam Turbines and Auxiliary Equipment

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ETD is pleased to announce it has just successfully won the project of guidelines for the operation and maintenance of steam turbines for a North African based plant.

The Steam Turbine (ST) is a critical part of the power generating cycle in thermal power plant and plays a key role in the conversion of thermal energy into mechanical energy in order to efficiently drive the generator and produce electricity. The ability to convert this energy in the most economical, reliable and efficient way possible is critical. Therefore, the overall system equipment has to be maintained and operated appropriately to ensure that the performance objectives are achieved.

As ETD have carried out various practical review and survey type projects on risk assessment, condition assessment, life assessment and cost analysis studies including review of clients’ data on cost issues, risk events, maintenance programs, reliability and availability of plants, fleet wise comparison/benchmarking of plant performance for European, USA and Asian utilities, etc. Therefore ETD were approached to develop a manual with best practice guidelines in the operation and maintenance of steam turbines and all associated auxiliary equipment of power plants to ensure performance needs are met and further improved. It was intended that these guidelines for the operation and maintenance of steam turbine and auxiliary equipment will include sufficient information for the users to effectively manage the equipment safety and integrity. ETD have also carried out comprehensive reviews of related areas such as ‘on-line monitoring tools’, ‘developments in risk-based maintenance programs and inspection techniques’, ‘guidelines for CCGT/HRSG lifing and risk-based approaches’, ‘plant cycling (both conventional and CCGTs/ HRSGs)’, damage due to cyclic operation and risk-based inspection, power plant component replacement strategies and technical and financial risks, etc. Through its Group Sponsored Projects (GSPs) ETD has developed new and more sophisticated techniques for power plant inspection and these have included the development of the portable Scanning Force Microscope (SFM), Electrical Discharge Sampling Equipment (EDSE) - a spark erosion device for ‘boat sampling’, and its precision portable hardness tester known as the ‘Smart Sleeve’.

This manual is aimed to introduce plant staff to the role of steam turbines and their auxiliaries in power stations and provide an understanding of their workings and benefits. There are significant variations in the design and structure with the various manufacturers and this will be generally addressed.

The manual will offer a practical guide as to how steam turbines and their associated auxiliaries are constructed, operated and maintained with emphasis on the best practices. The construction sections detailed design principles and the materials utilised. Later sections will cover best operating and maintenance issues under varying operating scenarios and finally the thermodynamics and efficiency considerations of steam turbines will be addressed.

For more information on our other specialist services including operation and maintenance, please click here.

Recent Completed Project on Failure Analysis of HRSG IP Economiser Outlet Header Tube

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ETD is pleased to announce the successful recent completion of a root cause failure analysis project for a North American based plant.

The plant was experiencing a failure of the IP Economiser outlet header tube. During the HRSG inspection, a pin hole leak was observed on the stub tube of IP Econ OH and the plant decided to replace the portion. The pin hole leak was found 6mm away from header-tube weldment (fillet weld). After the incident, the client completed extensive inspection on the header and dye penetrant test and no abnormalities were found. Therefore, ETD was invited to submit a proposal to carry out failure analysis of this IP econ tube sample removed from the failed area. The work involved performing tube failure analysis study based on laboratory testing and assessment of one removed tube sample.

The objectives and scope of the work to be carried out for one tube sample was:

  • Visual and dimensional examination of the tube sample, including examination of the failure/damage location appearance and condition of internal and external tube surfaces and any deposits;

  • Metallographic examination of the tube sample to assess the condition of the microstructure and to identify the damage/failure mechanism(s);

  • Hardness testing and evaluation to determine the equivalent tensile strength values (using published hardness/UTS correlation tables) to assess the mechanical strength or softening of the tube material;

  • Chemical analysis of base material to determine the chemical composition of the tube material to establish actual material constituents;

  • Chemical analysis of internal oxide/ deposits to determine the presence of impurities and constituents that may lead to the failure (depending on the oxide thickness);

  • Estimation of tube operating temperature based on measurements of steam-side oxide thickness, and evaluation of remaining creep life;

  • Review of design drawings, tube arrangement, operating parameters, previous failure and maintenance history;

  • Root Cause Failure Analysis (RCA) based on the findings of above investigations;

  • Report covering results of investigations, failure analysis & recommendations for remedial actions to prevent repeat tube failures.

ETD has established expertise in the failure analysis. For more information about our failure analysis services please click here.

Recent Completed Project on Review of Tube Deposit Analysis Reports and Provide Recommendations for Boiler Chemical Cleaning

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ETD is pleased to announce the recent completion of a root cause failure analysis project.

A European based client approached ETD to provide a quote concerning matters on its boiler and was asked to perform review of 10 reports for tube deposit analysis and make recommendations for boiler chemical cleaning.

The scope of the work carried out included:

  • Reviewing previous 10 reports of tube deposit analysis conducted by a third party;

  • Reviewing design drawings of tube arrangement, design & operating parameters, previous failure and maintenance history of the boilers;

  • Making some risk calculations to establish the criticality of the situation to determine whether the boiler chemical cleaning is required immediately or not;

  • Making recommendations on the cleaning solvents (i.e. suitable solvents used for boiler tube chemical cleaning purposes) based on the results of reports review;

  • Preparing a final report covering results of all above investigations & recommendations for any suitable actions to be taken for safe operation of the boiler.

ETD has established expertise in the failure analysis. For more information about our failure analysis services please click here.

Recent Completed Project on Providing Services for Thermo-Mechanical Fatigue (TMF) Testing, Data Analysis and Life Assessment and Providing Materials Database

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ETD is pleased to announce the successful recent completion of a Thermo-Mechanical Fatigue (TMF) Testing project.

A Middle Eastern client is currently performing research on advanced materials for Gas Turbines. One of the scopes of this research is to study the effect of thermal fatigue on gas turbine hot section components. The management’s interest is to conduct Thermal Fatigue Tests (TMF) on gas turbine blades and vanes. The client does not have the facilities and expertise to conduct these tests. Therefore, they decided to collaborate with international research companies which have the expertise and test facilities for thermal fatigue testing and are prepare to train their engineers in such testing, post-test data analysis, life assessment, and, support in technology transfer and capacity building.

ETD were approached to send proposal for such a collaborative project by providing services for Thermo-Mechanical Fatigue (TMF) testing, TMF data analysis & Life assessment and provide material database with particular reference to GT Materials.

The scope of the work included:

  • Conducting TMF tests for gas turbine materials – ETD provided services for TMF testing. Dependent upon the size of the components being sampled, the tests were small-scale specimen tests on GT materials of interest to the client.

  • Post Analysis of TMF Samples after Fracture – Post-test assessment was performed on all the TMF specimens after fracture. This analysis was performed to assess the damage and to determine the material degradation. Photographic evidence of the microstructures and hardness measurements were performed to be compared with the acceptable or expected range to provide further insight into the condition of the material.

  • Performing component life assessment – ETD performed life assessment of the selected materials based on the results of the TMF tests

  • Providing database of gas turbine materials for creep-fatigue mechanism – In principle, creep is the dominating damage mechanism at most GT high temperature critical locations. In light of ETD experience, the effects of creep interactions cannot be ignored in HGP lifetime assessment. Therefore, ETD provided a materials database considering creep fatigue interaction mechanism of gas turbine materials. This was done by collecting data from various sources including ETD’s various industry and research links, published literature and its own sources.

  • Submitting a Final Report – A report was then issued detailing the findings with photographic records including test results, data analysis, microstructure images and component integrity analysis results.

For more information on our Life Assessment services please click here.

Recent Completed Project on Root Cause Failure Analysis of Waterwall Tube Sample

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ETD is pleased to announce the successful recent completion of a root cause failure analysis project.

A Middle Eastern based client was experiencing frequent boiler water wall tube failures and some of the tubes have ruptured. Due to the number of frequency of tube failures experienced in boiler water wall the urgency to be able to identify the problem and take palliative measures to stop or reduce the failure is evident. ETD was approached to provide a quotation to perform Root Cause Failure Analysis (RCA) of a Waterwall Tube Sample.

The principle objective of this investigation was to examine the failed tubes samples (two samples from two separate incidents) in order to determine the failure / damage mechanism(s), to assess the micro structural and mechanical condition of the tube material, to examine the internal and external surfaces of the tubes for corrosion / oxidation damage and to examine them for the presence of cracks and manufacturing defects. This led to the identification of the root cause of the failures and allowed ETD to make recommendations concerning remedial actions that may be possible for improving the tube life and avoiding repeat failures.

The scope of the work carried out was:

  • Review of the plant operation and tube failure history;

  • Visual and dimensional examination of the two tube samples;

  • Metallographic examination to determine the failure/ damage mechanism(s) to assess the micro structural condition of material and to identify any micro structural deterioration or defects (cracking, corrosion, etc.);

  • Hardness evaluation;

  • Chemical analysis of the tube bore deposits to determine the cause(s) of cracking and the chemical cleaning agent most appropriate for the job.

  • Deposit thickness will also be determined which also determines if chemical cleaning is required and what type. Recommendations will be made for suitable chemical cleaning companies, if required.

A full report was then issued detailing the findings of the investigation with all analytical data and photographic records. Including recommendations for appropriate chemical cleaning solvent formulation based on the analytical data.

For more information on our Failure Analysis services please click here.

ETD nominated for the 2nd year running as ‘Best Practice Representative’ by the UK Parliamentary Review

European Technology Development Ltd. (ETD) is an SME based in Surrey, UK, and has been established now for over 20 years. It provides technical consulting services to power & process plant worldwide. ETD’s services are supported by its state-of-the-art research carried out mainly in collaboration with the UK, European and international industry and research institutes. ETD was first given the UK Parliamentary Review ‘Best Practice Representative’ Award in 2017. This year again it has received the 2018 ‘Best Practice Representative’ Award for its innovative Research & Development and support to industry worldwide. ETD’s Parliamentary Review coverage can be viewed here.

  ETD’s Managing Director Dr Ahmed Shibli with Rt Hon The Lord Pickles, Chairman of The Parliamentary Review, in the Houses of Parliament, UK.

ETD’s Managing Director Dr Ahmed Shibli with The Rt Hon Lord Pickles, Chairman of The Parliamentary Review, in the Houses of Parliament, UK.

Founded with former UK minister The Rt Hon David Curry, The Parliamentary Review's primary aim is to showcase the work of a number of leading UK organisations across the public and private sector. The publication features exclusive forewords from the Prime Minister and the BBC's Andrew Neil alongside unique content from representative organisations within each policy sector. The resulting document serves as a reliable and balanced projection of how British industry has been affected and what may be expected in the future as a result.

Writing in last year's Review ETD emphasised the importance of international collaboration, with 90 per cent of their business coming from overseas (Europe, North America, Japan, South Africa and Asia). In this year's article they turn their attention to highlighting the importance of partnerships with British universities and research institutes.

With comments from the prime minister regarding a "Modern Industrial Strategy that is strengthening the foundations of our economy", the 2017/18 edition of The Parliamentary Review presents a summary of the opportunities and concerns for consultancy and engineering firms alike.

Daniel Yossman, executive director of The Parliamentary Review, has praised this year's Review as one not to be missed. "With representatives from across the country coming together to raise standards and share best practice, this year's Review provides some of the most shrewd reading for politicians, educators, and business leaders alike."

Writing in The Review, the prime minister says that "British politics provides ample material for analysis in the pages of The Parliamentary Review."