Boiler Tube Failure Mechanisms

Unless the root cause of a fossil boiler tube failure is accurately identified, there's a good probability that history will repeat itself. This new SI Webinar provides an overview on determining the responsible tube failure mechanism, with an emphasis on accurate metallurgical analysis to properly identify the failure's root cause. The Webinar includes advice on removing, marking, and shipping pipe samples; a checklist of needed failure background information such as tube location and specifications, design and operating parameters, operating hours, total starts, and cycle chemistry; plus precautions on how to distinguish between look-alike failure mechanisms. As part of SI's ongoing efforts to help clients eliminate boiler tube failures, SI has recently expanded its chemical analysis, mechanical properties test, microstructural analysis, and cycle chemistry capabilities.

Presented on: May 20, 2008
Instructor: Wendy Weiss
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About the Instructor

Wendy Weiss has a MS in Materials Science and Engineering from the University of Texas at Austin, and a BS in Materials Engineering from the New Mexico Institute of Mining and Technology. Her specialties are failure and metallurgical analysis, materials evaluations and inspection, and risk assessment and risk management.

Financial Risk Optimization for Run/Repair/Replace Timing

Plant component run, repair, or replace decisions are often tough calls. Plant owners need unit reliability, but are pressured by aging equipment and available repair/replacement budgets. This SI Webinar offers a different approach to financial risk optimization (FRO), using financial/decision analysis methods already employed by corporate financial planners. The presentation includes a comprehensive overview of FRO; how to determine high-risk components using failure history data and plant personnel interviews; how to estimate probability of failure v.s. time from history data and interviews; incorporation of probabilistic remaining life analysis results after component inspection; the structure of a risk-based methodology that optimizes run/repair/replace timing to minimize risk; and determination of highest-risk-driving components and how they affect run/repair/replace decisions.

Presented on: September 24, 2008
Instructor: David Mauney
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Generator Rotor Inspection & Life Assessment

Many generator rotor components—including rotor bores, retaining rings, rotor tooth-top dovetails, and shafts—require close inspection and life assessment. This SI Webinar covers inspection techniques, including linear phased-array (LPA) ultrasonic dovetail inspections, as well as LPA inspections of rotor shafts for under-coupling cracking initiated by fretting fatigue. The presentation also discusses how to analyze inspection data for each of the above components.

Presented on: March 6, 2008
Instructors: Larry Nottingham, Scott Rau
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About the Instructors

Larry Nottingham holds a BS in Mechanical Engineering from the University of Pittsburgh, and has over 35 years of experience in design, maintenance, and nondestructive evaluation of turbines, generators, and other power plant equipment. He also has extensive experience in development and delivery of advanced nondestructive evaluation systems and procedures for numerous power plant applications, with emphasis on turbine and generator components and high-energy piping.

Scott Rau, PE has a MS in Structural Engineering from the University of California, Los Angeles. He has extensive experience in stress analysis, including finite element analysis and modeling of structures and components with linear or non-linear behavior; dynamic system response and time history analysis; and transient thermal elastic-plastic analysis. Rau has performed remaining life evaluations of over 50 high-energy piping systems, and of similar numbers of steam turbine and generator rotors.

High-Energy Piping Lifing Techniques

When performed correctly, lifing provides a heads-up on potential high-energy piping problems. This new SI Webinar outlines lifing procedures, concentrating on high-temperature main steam and hot reheat piping systems. Pre-inspection evaluation topics include SI's Vindex™ risk-ranking methodology; piping stress analysis; creep or creep-fatigue life fraction calculations; and MPC OmegaPipe Analysis. Post-inspection evaluation topics cover correlation of microstructural damage levels with Life Fraction Consumed and NDE detection sensitivity; fracture mechanics-based creep or creep-fatigue crack growth analysis; MPC OmegaPipe Life Assessment; and metallurgical plug sample analysis to refine analytical life predictions.

Presented on: August 19, 2008
Instructor: Mario Berasi
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About the Instructor

Mario Berasi has a BS in Mechanical Engineering from the University of Pittsburgh, and a MBA from the University of Akron. He is experienced in fossil plant condition assessment for utility and industrial clients. Berasi is also expert in finite element analysis techniques, as well as structural analysis and creep fatigue evaluation of fossil-fired boiler components.

Inspection Technologies for Boiler Tubing

Careful planning is essential for successful boiler tubing inspections, and this recent SI Webinar discusses exactly how to ensure that all inspections proceed as anticipated. Topics covered include defining what you're looking for and where to look; identifying optimal inspection techniques for each damage mechanism; qualifying inspection personnel; providing inspection support functions and preparing the area to be inspected; defining acceptance criteria; and developing a contingency plan for either additional analysis or immediate repair. SI's Webinar also emphasizes the importance of properly documenting every inspection as part of a fossil unit's record.

Presented on: June 3, 2008
Instructor: Matt Dowling
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About the Instructor

Matt Dowling holds a BS in Mechanical Engineering from the University of Connecticut, and has 15 years of experience in condition assessment and repair welding of critical boiler piping and auxiliary components. Dowling has authored numerous technical papers on specialty repair welding techniques for the fossil power industry.

Inspection Technologies for High-Energy Piping

High-energy piping inspections are high-stakes examinations that require impeccable planning. This new SI Webinar discusses all the necessary steps, including pre-planning the inspection, prioritizing inspection locations, identifying the correct inspection technique for the specific condition, and in-process auditing to ensure that inspections are on track. The Webinar uses a case study of seam-welded hot reheat piping inspection to illustrate the correct approach. Inspection of creep strength-enhanced ferritic steel components is also discussed.

Presented on: July 31, 2008
Instructor: Larry Nottingham
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About the Instructor

Larry Nottingham holds a BS in Mechanical Engineering from the University of Pittsburgh, and has over 35 years of experience in design, maintenance, and nondestructive evaluation of turbines, generators, and other power plant equipment. He also has extensive experience in development and delivery of advanced nondestructive evaluation systems and procedures for numerous power plant applications, with emphasis on turbine and generator components and high-energy piping.

Life Management Issues for Creep Strength Enhanced Ferritic Steels

A summary of in-service experience with Grade 91 steel will be presented. It is apparent that the advantages offered by creep strengthened ferritic steels, such as Grade 91, can only be realized with careful control of composition and fabrication methods. Appropriate quality assurance checks must be performed to ensure that properties meet requirements. Where these tests indicate that properties are marginal or below expectedalues, follow up programs must be carried out to underpin analysis of long term performance. Because of concerns over accelerated creep damage development in weld HAZs, there are significant benefits to using advanced NDE techniques to identify and characterize defects.

Presented on: October 14, 2009
Instructor: Jonathan Parker
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About the Instructor

Jonathan Parker, Director, Technology Developmoent, has expertise in characterization of materials structures and properties has been applied to solving problems of failure cause analysis, optimization of manufacturing processes and remnant life assessment of components.

Overall Approach to Boiler Tube Failure Reduction

Boiler tube failures remain the primary cause of forced outages at fossil-fired units, but most are preventable. This new SI Webinar presents a proven approach to reducing boiler tube failures that relies on correctly identifying and addressing root causes and on optimizing unit cycle chemistry. Management-supported, multi-disciplinary teamwork that enlists the support of all engineering, operation, and maintenance staff is also a key part of the plan. The root-cause approach has been endorsed by EPRI® for 20 years. SI provides complete boiler tube failure reduction support, including metallurgical analyses, deposit and scale analyses, nondestructive examination, life assessment, root-cause analysis, and root-cause analysis training.

Presented on: May 8, 2008
Instructor: Barry Dooley
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About the Instructor

Barry Dooley holds a B.Eng and a PhD—both in Metallurgy—from the University of Liverpool, as well as a D.Sc. from Moscow Power Institute. His special expertise is in programs on cycle chemistry, boiler tube failure reduction, cycle chemistry improvement, heat-recovery steam generator reliability, and flow-accelerated corrosion. He is author or co-author of over 260 technical papers, editor of 14 international conference proceedings, and co-author of books on boiler tube failures, steam turbine damage mechanisms, and flow-accelerated corrosion in power plants. Dooley is also executive secretary for the International Association for the Properties of Water and Steam (IAPWS).

Overall Approach to Managing Degradation of High-Energy Piping

High-energy piping at fossil-fired units is susceptible to a host of damage mechanisms: creep, fatigue, creep fatigue, corrosion fatigue, and flow-accelerated corrosion. This Webinar provides an overview of SI's approach for managing degradation in main steam, cold reheat, hot reheat, and feedwater piping. The approach includes diligent review of unit history and data, prioritization to allocate resources to highest-risk components, and appropriate inspection, monitoring, and maintenance. The Webinar includes discussion of Vindex™, SI's vulnerability index methodology for risk-ranking girth welds within a single HEP piping system or across several systems.

Presented on: July 1, 2008
Instructors: Steve Gressler, Mario Berasi
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About the Instructors

Steve Gressler, PE holds a BS in Metallurgical Engineering, University of Pittsburgh. Throughout his career he has been involved in failure analysis and maintenance of power generation systems and equipment, with experience in laboratory analysis, field inspection, maintenance practices, and engineering evaluation related to fossil power plant components, particularly boiler and high-pressure piping. Gressler is an expert in optical and scanning electronic microscopy.

Mario Berasi has a BS in Mechanical Engineering from the University of Pittsburgh, and a MBA from the University of Akron. He is experienced in fossil plant condition assessment for utility and industrial clients. Berasi is also expert in finite element analysis techniques, as well as structural analysis and creep fatigue evaluation of fossil-fired boiler components.

Turbine Disk Rim Inspection and LPRimLife Analysis

This presentation addresses the challenging decisions utility owners/operators are facing relative to cracking in turbine rotor disk rim blade attachment dovetails. As the turbine fleet ages, indications of significant cracking in the dovetails are occurring at an increasing rate. Repair options are expensive, and replacement options even more so. Consequently, utilities are frequently challenged to justify when it is appropriate to repair or replace and, on the other hand, when continued operation for a specified interval is justified on the basis of acceptable risk of failure. The presentation will discuss various ultrasonic inspection techniques used for the detection of indications the attachment region of LP rotors. Examples of the ultrasonic indications will be presented, including specific examples of single indications occurring on a single hook and regions where two or more hooks had indications stacked at the same circumferential location. Sizing means will be shown as well. The analytical portion the presentation will discuss the use of the LPRimLife code used in the lifetime analysis of blade attachments. LPRimLife assesses the risk of attachment failure from stress corrosion cracking as a function of continued operation. SI developed LPRimLife under an EPRI research contract, and has since provided assessments services to numerous power producers. The impact of several analysis variables will be discussed including the proximity of indications to the notch block; single hook versus stacked indications; and, overspeed trip limits.

Presented on: December 10, 2009
Instructors: Ronald O'Hara, Clifford Lange
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Turbine & Generator Rotor Bore Inspection & Life Assessment

Overly conservative assessments of the probability of turbine and generator rotor bore catastrophic failure can lead to unnecessary repairs or replacements. This SI Webinar discusses a balanced approach to inspection and life assessment to maximize the life of rotors, covering inspection, identification of damage mechanisms, operating condition assessment, material properties, acceptance criteria, and repair/replace/reinspect scheduling. SI's Webinar also includes information on new NDE techniques and new analysis tools for rotor bore applications.

Presented on: February 6, 2008
Instructors: Larry Nottingham, Scott Rau
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About the Instructors

Larry Nottingham holds a BS in Mechanical Engineering from the University of Pittsburgh, and has over 35 years of experience in design, maintenance, and nondestructive evaluation of turbines, generators, and other power plant equipment. He also has extensive experience in development and delivery of advanced nondestructive evaluation systems and procedures for numerous power plant applications, with emphasis on turbine and generator components and high-energy piping.

Scott Rau, PE has a MS in Structural Engineering from the University of California, Los Angeles. He has extensive experience in stress analysis, including finite element analysis and modeling of structures and components with linear or non-linear behavior; dynamic system response and time history analysis; and transient thermal elastic-plastic analysis. Rau has performed remaining life evaluations of over 50 high-energy piping systems, and of similar numbers of steam turbine and generator rotors.

Turbine Steam Chests and Valve Assessment

Details coming soon.

Presented on: December 17, 2009
Instructors: Allen Porter, Dan Peters
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About the Instructors

Allen Porter has an MS in Material Science from Southern Methodist University, and holds ASNT Level III Certification in ultrasonic and eddy-current testing. He has over 20 years of experience in the application, development, and qualification of nondestructive examination techniques and systems for the power generation and aerospace industries. Porter's expertise includes application of advanced NDE solutions, notably ultrasonic phased-array and eddy-current array technologies, and his experience spans procedure development, certification, and training in automated and phased-array ultrasonic inspection, as well as eddy-current inspection.

Vindex™: Ranking Procedure for High-Energy Piping Girth Welds

Limited inspection budgets put utilities in the difficult position of determining which high-energy piping and header girth welds to inspect. This new SI Webinar describes Vindex™ — Vulnerability Index — a semi-quantitative damage-ranking methodology that takes both inspection history and component characteristics into account. SI-developed Vindex provides structured risk-ranking for welds within a single piping system or across several systems. The damage consequences considered in SI's Vindex methodology consist of safety and/or lost power generation.

Presented on: July 16, 2008
Instructor: Scott Rau
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About the Instructor

Scott Rau, PE has a MS in Structural Engineering from the University of California, Los Angeles. He has extensive experience in stress analysis, including finite element analysis and modeling of structures and components with linear or non-linear behavior; dynamic system response and time history analysis; and transient thermal elastic-plastic analysis. Rau has performed remaining life evaluations of over 50 high-energy piping systems, and of similar numbers of steam turbine and generator rotors.