Fitness for Service (FFS) is a best practice and standard used by the oil & gas and chemical process industries for in-service equipment to determine its fitness for continued service. FFS serves as a rational basis for defining flaw acceptance limits and allows engineers to distinguish between acceptable and unacceptable flaws and damage based on industry recognized and generally accepted good engineering practices (RAGAGEP).
The FFS of any particular material is determined by performing a fitness-for-service assessment per standardized methods and criteria. Performing accurate FFS evaluations is an integral aspect of fixed equipment asset integrity management as an alternative to using the original construction design code. The FFS of a piece of equipment may be viewed both in terms of current and future FFS or remaining life.
Most equipment can continue in service despite small flaws, and to repair or replace equipment that can still be used would be an unnecessary and costly expense. In addition, unnecessary weld repairs can do more harm than good and create unnecessary risks to personnel in many cases.
API RP 579-1/ASME FFS-1, Fitness for Service, Second Edition, is one example of a FFS methodology currently used by industry professionals. In general, most FFS assessment standards are broken into multiple levels. Each successive level (e.g., Levels 1, 2 and 3 of the referenced API 579-1/ASSME FFS-1 standard) requires increasing amounts of data, calculations, effort, and cost to arrive at the most accurate outcomes and possible longer equipment remnant life. In addition to calculations, FFS involves the consideration of additional data (e.g. pitting patterns and depths, corrosion morphology or shape and depth, crack depths and lengths, operating conditions, materials properties, etc.). Inspection information is often critical input to a FFS assessment.
Is this definition incomplete? You can help by contributing to it.
|
January/February 2019 Inspectioneering Journal
By Greg Garic at Stress Engineering Services, Inc.
The distinction between primary and secondary loads is certainly important in analysis of pressure systems. But this distinction is also important for plant operations and reliability engineers to keep in mind when dealing with day-to-day problems. |
|
January/February 2019 Inspectioneering Journal
By Houssam Sabry at ADNOC LNG, and Asad Ali at ADNOC LNG
An effective RBI system implementation results in, not only safeguarding your assets & people, but can also reduce unnecessary inspection activities that may be required due to conventional & nonsystematic approaches. |
|
November/December 2018 Inspectioneering Journal
By Greg Garic at Stress Engineering Services, Inc.
In this edition of the FFS Forum, Greg Garic addresses some issues associated with inspection of vessels that have been in service for a number of decades. He also provides some tips and guidelines for reliability and inspection to follow when inspecting these older vessels. |
|
September/October 2018 Inspectioneering Journal
By Greg Garic at Stress Engineering Services, Inc.
In this column, I touch on what I see as an underused FFS technique for corrosion assessment: point assessment of corrosion – a technique that does NOT require a thickness grid. The reason I find this technique useful is largely because it’s so easy and cheap to implement. |
|
July/August 2018 Inspectioneering Journal
By Greg Garic at Stress Engineering Services, Inc.
API 579-1 is a complex document covering several different types of equipment that may contain flaws or damage. Due to its complexity, this article condenses it into six things you need to know. |
|
May/June 2018 Inspectioneering Journal
By Geoff Clarkson at UTComp, Inc.
With no industry consensus documents in existence that provide guidance for determining FFS of FRP, this article provides a case study that illustrates how an existing European design standard on GRP tanks can be used to calculate expected changes in FRP for FRP vessels. |
|
May/June 2018 Inspectioneering Journal
By Dhananjay H. Rawal at Systech Consultancy Services
This article details the experience an oil company had when using FEA to evaluate the implications of a damaged pipeline. Specifically, it presents an efficient method that combines analytical techniques with FEA to determine the pipeline’s fitness for continued service. |
|
May/June 2018 Inspectioneering Journal
By Ralph E. King P.E. at Stress Engineering Services Inc., John Norris, P.E. at Stress Engineering Services, Dr. Kannan Subramanian, Ph. D., P.E. at Stress Engineering Services Inc., and Daniel Ayewah, P.E. at Stress Engineering Services Inc.
There is concern in the industry over recent findings of reduced toughness fittings and flanges at risk of brittle fracture. This article provides an overview; possible contributors; measures taken to address; and a proposed FFS approach to address the issue. |
|
March/April 2018 Inspectioneering Journal
By Simon Yuen, P.E. at Suncor Energy Inc., and Ken Gottselig at BP America Production Company
Hot spots – localized areas of overheating in pressure equipment – can lead to deformation or even loss of process containment. It is important to understand the effects of elevated temperature caused by hot spots on the mechanical integrity of equipment. |
|
September/October 2017 Inspectioneering Journal
By Arun Sreeranganathan at Stress Engineering Services Inc., and John Norris, P.E. at Stress Engineering Services
Fired heaters are among the most critical equipment in refineries and chemical plants, and failure of heater tubes presents significant safety and financial concerns. This article provides an overview of what a fired heater tube mechanical integrity program should include. |
|
September/October 2017 Inspectioneering Journal
By Tyron Kimble at Sonomatic
Due to its high-cost, Level 3 FFS is typically carried out after Levels 1 or 2 and only in extreme cases. However, advancements in inspection technology and improved use of inspection data have made Level 3 analysis more practical and affordable, even in less critical cases. |
|
November/December 2016 Inspectioneering Journal
By Nolan L. Miller at SASOL North America
This article will go through the methodology of each process that could be used in determining the structural component for the required pipe wall thickness, but will focus on the use of Beam Flexural Stress calculations and Beam Deflection calculations to determine the structural component of the required pipe wall thickness calculation. |
|
November/December 2016 Inspectioneering Journal
By Michael Turnquist at Quest Integrity Group
This article exhibits how modern inspection methodologies combined with innovative computational analysis practices demonstrate the value of conducting fitness-for-service (FFS) assessments on sectional piping. |
|
May/June 2016 Inspectioneering Journal
By Douglas Marriott at Stress Engineering Services Inc., Shannon Read at Stress Engineering Services Inc., and Arun Sreeranganathan at Stress Engineering Services Inc.
Aging equipment, along with more aggressive service, makes it more important than ever to carry out fitness-for-service (FFS) assessments in support of run/repair/replace decisions. Testing material in the service-degraded condition enables quantification of the material condition and provides increased accuracy in FFS evaluations of these components. |
|
March/April 2016 Inspectioneering Journal
By Tim Hill at Quest Integrity Group
Achieving fired heater reliability in conjunction with meeting performance standards can be a challenging feat. Performance is a measure of the degree to which the fired heater is in an operable condition at any given time. |
|
November/December 2015 Inspectioneering Journal
By Ralph E. King P.E. at Stress Engineering Services Inc., and Brian Olson at Stress Engineering Services Inc.
To ensure the mechanical integrity and fitness-for-service (FFS) of equipment, facility managers, reliability engineers, and inspection technicians must understand the HTHA damage mechanism. |
|
July/August 2015 Inspectioneering Journal
By Greg Alvarado at Inspectioneering Journal
Asset managers need to know when repairs and replacement are required for many reasons, including safe operation, accurate budgeting, replacement planning, and on-going reliability. When predicting design life based on a simple, linear corrosion rate versus remaining thickness, metallurgical degradation, or crack propagation rates are often not accurate or realistic. Even if the models are good, things change. |
|
July/August 2015 Inspectioneering Journal
By Joe Frey, PE at Stress Engineering, Inc., Lange Kimball at Stress Engineering Services, and Britt Bettell at Stress Engineering Services
This article introduces portions of a “Best-In-Class” Fitness-for-Service (FFS) program that includes the performance of regular visual inspections of pipe supports and hangers, coupled with in-situ load testing of suspect supports. This program can give the plant engineer the knowledge he needs to make sound operational and maintenance decisions. |
|
May/June 2015 Inspectioneering Journal
By David A. Hunter at Neptune Research, Inc.
In recent years, the growing use of composite repair systems for the rehabilitation of piping systems in the refining and chemical industries has increased the need for associated technologies for their manufacturing, installation, and inspection. One critical aspect of these repair systems is how to inspect and validate them for fitness for service. This article covers the testing completed for fiberglass and carbon fiber composite repair systems with specialty epoxy for full inspection capabilities. |
|
Blog
March 16, 2015
For many years, it has been common practice in the petrochemical industry to use fitness-for-service (FFS) evaluations to determine whether or not a finding during an inspection would prevent a part from being able to be returned to service. |
|
Blog
January 5, 2015 By Jeremiah Wooten at Inspectioneering, LLC.
There are numerous benefits to adding fitness-for-service (FFS) assessments to energy sector reliability projects. The acceptance of API 579/ASME FFS-1 is increasing across the energy sector and other industries, as these benefits have been demonstrated in a wide range of projects. |
|
Blog
December 22, 2014 By Nick Schmoyer at Inspectioneering
One of Inspectioneering's most popular topics is Fitness for Service (FFS). This blog post will provide you with some highlights from some of our most popular articles related to FFS. It's only a small sample of what we offer, but it should still prove useful to readers both old and new. |
|
May/June 2014 Inspectioneering Journal
By Luciano Narcisi at GIE
As an RBI consultant, I frequently get involved in discussions spawned from a misunderstanding of the relation between Risk Based Inspection (RBI) approaches and Fitness for Service (FFS) assessments. Questions like: If thickness is below the minimum required by design, why does the risk stay so low? |
|
May/June 2014 Inspectioneering Journal
By Hugo Julien, P.E. at GCM Consultants, Serge Bisson at GCM Consultants, and Guy St-Arneault, P.E. at GCM Consultants
Inspections, repairs, modifications, or Fitness-For-Service (FFS) assessments on an old, unfired ASME Section VIII (Div. 1) pressure vessel - Which ASME Section VIII (Div. 1) Code Edition should you use? |
|
March/April 2014 Inspectioneering Journal
By Hugo Julien, P.E. at GCM Consultants, and Guy St-Arneault, P.E. at GCM Consultants
Since important decisions will be based on the results of the fitness-for-service (FFS) determination, you need to be sure that you have a strong FFS team. But what are the key ingredients of a good FFS team? This article provides some guidelines to help you answer this question. |
|
January/February 2014 Inspectioneering Journal
By Antonio Seijas at Phillips 66 Company
Fired furnaces in the petrochemical and refining industry are critical pieces of equipment that can have a major impact on process unit safety, reliability, and economics. They are complex pieces of equipment, where tubes and other pressure boundary components might fail due to relatively short periods of upset conditions. |
|
November/December 2013 Inspectioneering Journal
By Michael Turnquist at Quest Integrity Group
While there are many types of damage mechanisms that can occur in a piece of equipment, localized metal loss is one of the most common. If an inspection reveals that metal loss has occurred, many questions are raised... |
|
November/December 2013 Inspectioneering Journal
By Ralph E. King P.E. at Stress Engineering Services Inc.
Auto-refrigeration is a process where an unintentional and/or uncontrolled phase change of a hydrocarbon from a liquid state to a vapor occurs, resulting in a very rapid chilling (refrigeration) of the liquid containing local equipment and/or piping. This phenomenon can result in a catastrophic ‘break-before-leak’ scenario commonly referred to as brittle fracture. |
|
September/October 2013 Inspectioneering Journal
By Joe Pikas at Technical Toolboxes
Even though oil and gas pipelines and their related facilities are generally safer for people and the environment compared to other means of transportation, occasional leaks and failures due to corrosion and other defects have become an issue in maintaining pipeline integrity. |
|
Blog
September 9, 2013 By Greg Alvarado at Inspectioneering Journal
We’ve been discussing Scalable Accuracy and its use related to Lifecycle Management technologies available to owner/operators. The last few topics have included Risk Based Inspection, Fitness for Service using Accuracy, the approach for Equipment Lifecycle Management and, to lay the foundation for proper thinking, making the case for Scalable Accuracy. |
|
Blog
August 26, 2013 By Greg Alvarado at Inspectioneering Journal
This blog post continues our discussion from the previous posts on scalable accuracy. We started with a post outlining the steps prior to using scalable accuracy. Then we walked through the scalable accuracy approach to Fixed Equipment LCM. While I normally start with RBI when discussing scalable accuracy, it will be easier to use an example of Fitness for Service as our starting point. |
|
Blog
August 19, 2013 By Greg Alvarado at Inspectioneering Journal
Continuing from last week’s blog, I want to go in depth into scalable accuracy for fixed equipment lifecycle management. In this post, I want to outline the scalable accuracy approach to fixed equipment lifecycle management. |
|
Blog
August 12, 2013 By Greg Alvarado at Inspectioneering Journal
In the next few blog posts, we will be going in depth on scalable accuracy. This post walks through the thinking needed prior to initiating. Then we will discuss two technologies immediately available to plant operators for fixed equipment life-cycle maintenance: Risk Based Inspection (RBI) and Fitness for Service (FFS). |
|
July/August 2013 Inspectioneering Journal
By James R. Widrig at Quest Integrity
Inspection and fitness-for-service assessments of critical in-plant piping systems are a concern for the chemical industry. This presents a potentially insurmountable task and discovery of a number of areas where the condition is at risk. |
|
Blog
April 29, 2013 By Greg Alvarado at Inspectioneering Journal
This is my second of three posts on Key Performance Indicators (KPIs) based on requests and discussions on the issue.  In part 1 of this series I provided a brief overview of KPIs and their ability to predict good, poor, and sometimes dangerous performance in our quests to achieve certain objectives and goals. |
|
Blog
March 3, 2013 By Greg Alvarado at Inspectioneering Journal
This is a question with which I frequently like to start the API RBI 580/581 training course when I am instructing. It is meant to provoke the attendees to really think hard about why they order an inspection or really think about inspection strategies. |
|
March/April 2013 Inspectioneering Journal
By Greg Garic at Stress Engineering Services, Inc.
If an operator finds cracking in a furnace waste heat boiler, excessive thinning in an absorption tower, or severe bulging in a converter, FFS assessments—not standard code analyses—are needed to evaluate the unit’s mechanical integrity. FFS assessments, according to the American Petroleum Institute (API), are “quantitative engineering evaluations that are performed to demonstrate the structural integrity of an in-service component containing a flaw or damage.” |
|
January/February 2013 Inspectioneering Journal
By Devon Brendecke, P.E. at Quest Integrity Group
The benefits of adding fitness-for-service (FFS) assessments to energy sector reliability projects are numerous. The acceptance of API 579/ASME FFS-1 is increasing across the energy sector and other industries, as these benefits have been demonstrated in a wide range of projects. Several of these benefits are illustrated in this article using real-world examples. |
|
September/October 2012 Inspectioneering Journal
By Peter Carter, PhD, PE at Stress Engineering, Inc., Joe Frey, PE at Stress Engineering, Inc., and Mike Guillot, PhD, PE at Stress Engineering, Inc.
An all too familiar scenario in power plants is one in which an inspection finding occurs late in an outage and consequently, the return to service date may need to be postponed to allow time for corrective action. Historically, cracks or thinned spots were typically repaired without question. |
|
January/February 2012 Inspectioneering Journal
By Devon Brendecke, P.E. at Quest Integrity Group
Thanks to constantly improving technology developments, inspection of atmospheric storage tanks has yielded better data which, when used as input, improves the accuracy of advanced assessment techniques. Coupling the improved inspection data with an advanced engineering assessment often means that tank operators are able to postpone repairs until the next shutdown, eliminate the need for repairs or be exempt from hydrostatic testing. |
|
January/February 2012 Inspectioneering Journal
By Greg Alvarado at Inspectioneering Journal
The various factors of the challenge, e.g. creating effective and then efficient inspection strategies, are at the crux of the decision process. Within each of these factors are questions that must be answered. The answers should be well thought through and provided as part of your risk-based inspection analysis process. |
|
January/February 2012 Inspectioneering Journal
The design and fabrication of nuclear pressure vessels and piping components are governed by the rules of Section III of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. This Code, which aims to to ensure high levels of structural integrity for safe nuclear plant operation, requires radiographic examination of Class 1 and 2 pressure boundary butt welds to detect structural flaws introduced during welding. |
|
November/December 2011 Inspectioneering Journal
By Greg Alvarado at Inspectioneering Journal
The original article on scalable accuracy which laid the groundwork for the concept was published in the March April 2011 issue of the Inspectioneering Journal, entitled Scalable Accuracy, Key Roles of Risk Based Inspection and Fitness for Service, Equipment Life-Cycle Management Process. This article is reprinted immediately following this article for ease of reference. |
|
March/April 2011 Inspectioneering Journal
By Greg Alvarado at Inspectioneering Journal
Two technologies, immediately available to plant operators for fixed equipment life-cycle management are Risk-Based Inspection (RBI) and Fitness for Service (FFS), two best practices that optimally work together or can standalone. Both have abilities of scalable accuracy. |
|
January/February 2011 Inspectioneering Journal
By John Reynolds at Intertek
In the first article in this series entitled How to Put It All Together - Guide to Organizing a Successful PEI Program, (1) I provided an overview of the necessary Management Systems (MS) for a successful program to achieve excellence in pressure equipment integrity (PEI). This is the sixth article in that series. |
|
November/December 2010 Inspectioneering Journal
Understanding, predicting, detecting and controlling high-temperature hydrogen attack (HTHA), have been elusive goals of materials engineers and scientists for over 70 years. The destruction of low alloy steel components exposed to hydrogen through the formation in the microstructure of high-pressure methane bubbles has led to many failures, fires, and sometimes deaths. |
|
May/June 2009 Inspectioneering Journal
By Fernando Vicente at ABB
In the oil and gas industry, pressure vessel integrity is a major concern. After internal and external inspections various anomalies or defects can be reported and repairs could be required for pressure vessels in order to restore its original condition. The first question for engineers, operators and managers is, can we keep operating at this pressure level? Is it safe? Or do I have to take it out of service to repair? |
|
September/October 2007 Inspectioneering Journal
The assessment procedures in this Standard can be used for Fitness-For-Service assessments and/or re-rating of equipment designed and constructed to recognized codes and standards, including international and internal corporate standards. |
|
May/June 2007 Inspectioneering Journal
By Greg Alvarado at Inspectioneering Journal
This is part 2 in a multi-part series. Part 1 set the stage in explaining the basics of RBI. As I am most familiar with API Base Resource Document 581, I will continue to use this technical basis for this article. |
|
May/June 2006 Inspectioneering Journal
Revisions to the California Code of Regulations Title 8 Petroleum Safety Orders are nearly complete and the new regulations should be published late summer 2006. The regulations will affect both drilling and production facilities and refining, transportation, and handling facilities. |
|
November/December 2005 Inspectioneering Journal
A few years ago, TWI investigated a corrosion failure in a 30 inch crude oil pipeline that regrettably led to an explosion and fire, and the death of several operating personnel. The pipeline was designed to ASME B31.4 and the investigation found that corrosion resulted from the break-down of the external coating. The exposed area of pipe was too large for the cathodic protection system. Pitting corrosion initiated at several locations that coalesced over a large area to cause failure by rupture. The lost production from this failure was 300,000 bbl/d. The corrosion in this pipeline was not detected before failure. However, if corrosion is found in service pressure equipment, there are safe guidelines available for inspection engineers to assess the fitness-for-service (FFS) of corrosion damage. |
|
July/August 2005 Inspectioneering Journal
By Jonathan D. Dobis at The Equity Engineering Group, Inc., and David N. French
This bulletin is part of a series of WRC Bulletins that contain the technical background and other information to evaluate damage mechanisms in various industries to facilitate the use of API 579. These bulletins, shown below, will be updated based on the latest knowledge and technology developed for identification of damage mechanisms. |
|
May/June 2005 Inspectioneering Journal
By Bob Stakenborghs, P.E. at Evisive Inc.
API is preparing to release the next edition of API 579 Fitness-For-Service (FFS) the first quarter of 2006. The many major enhancements that have been made to the next edition of API 579 will permit Owner-Users to evaluate new types of damage including HIC/SOHIC and Dentgouge combinations, and allow detailed remaining life assessments of components operating in the creep range. In addition, new procedures for stress analysis have been developed that will enhance the usability and accuracy o f Level 3 Assessments resulting in longer running times for damaged components. |
|
March/April 2005 Inspectioneering Journal
By Greg Alvarado at Inspectioneering Journal
We are happy to announce the 10-year anniversary of the inaugural issue of the Inspectioneering Journal! |
|
January/February 2005 Inspectioneering Journal
By Julian Speck at TWI Ltd., and Brigdet Hayes at TWI
The number of FFS assessments carried out by inspection engineers is expected to increase in the future, as operators "sweat" their ageing process equipment. The parameters required for assessments can be quite complex and interdependent. Therefore, a multidisciplinary peer review (involving stress analysts, NDE experts and materials engineers) is often necessary before acting on the findings of the even the most regular FFS assessment. Operators and inspection engineers using FFS assessments would do well to learn from previous failures. Author: |
|
May/June 2002 Inspectioneering Journal
By Greg Alvarado at Inspectioneering Journal, and C.P. Hsiao
We have discussed various factors that can affect the reliability of NDE techniques (i.e., probability of detection - POD and sizing accuracy) in Part 1. In general, it is difficult to quantify these uncertainties. In fact, it is impossible to fully quantify the uncertainties in NDE results. However, one can achieve a higher level of reliability by reducing or minimizing the uncertainties. We will discuss some of the steps one can take to minimize the uncertainties in NDE results. By minimizing or reducing the uncertainties in NDE results, FFS assessments can be less conservative, and thus provide more margin to the serviceability of the equipment. |
|
January/February 2002 Inspectioneering Journal
By Greg Alvarado at Inspectioneering Journal, and C.P. Hsiao
Safety, environmental and economic pressures are motivating process industry (e.g. refineries & petrochemical plants) operators to consistently improve equipment reliability performance, optimize expenses and more accurately target resources where they will provide the greatest benefit. These improvements yield improved return on net assets (e.g. pressure vessels, piping and tanks). Companies that can better assure that decisions about repairs or replacement of equipment are more accurately arrived at are heading in the right direction. In order to equip operators with tools for better decision making, the American Petroleum Institute, within the last few years, has introduced Recommended Practice (RP) 579 Fitness for Service (FFS), which had been in development for several preceding years. The latest versions of the widely used inspection codes; API 510 (pressure vessels), API 570 (piping) and API 653 (above ground storage tanks) now reference this RP as a tool for determining the fitness for service of these types of equipment when corrosion, cracking, or other forms of deterioration are found and in the case of re-rating equipment. |
|
November/December 2001 Inspectioneering Journal
By Greg Alvarado at Inspectioneering Journal
A typical risk based inspection (RBI) analysis should include past inspection results, tempered by confidence in those results. For example, API's (American Petroleum Institute) RBI methodology and software when calculating the likelihood of failure side of the risk equation asks for past inspection histories. This includes dates of past inspections for potential damage mechanisms, the effectiveness of those inspection techniques to find the anticipated damage and amounts of coverage. Via this logic, the program constructs a factor to represent the probable damage population scatter band and multiplies this times the entered corrosion rates, cracking susceptibilities or bulk damage rates. |
|
May/June 2001 Inspectioneering Journal
By Russell Orr at Metals Technologies Laboratories, CANMET, and John Bowker at Materials Technology Laboratory
The use of engineering critical assessment (ECA)of "fitness for service", for the evaluation of flaws and local wall thinning in pressure vessels is receiving a lot of attention in the petrochemical and utility industries. A rigorous methodology based on fracture mechanics and accurate flaw sizing can be used to assess the risk of operation of a damaged vessel by predicting the amount of damage that can lead to premature failure. |
|
March/April 2001 Inspectioneering Journal
By Gerrit M. Buchheim, P.E. at Becht Engineering Co., Inc.
With the publication of API RP 579 For Fitness-For-Service and the planned publication of API RP 580 for Risk Based Inspection in 2001, these technologies will find increasing application in maintenance and inspection planning. |
|
November/December 2000 Inspectioneering Journal
By John Reynolds at Intertek
Part 4 of this article continues to outline the 101 essential elements that need to be in place, and functioning well, to effectively and efficiently, preserve and protect the reliability and integrity of pressure equipment (vessels, exchangers, furnaces, boilers, piping, tanks, relief systems) in the refining and petrochemical industry. |
|
March/April 2000 Inspectioneering Journal
By Gerrit M. Buchheim, P.E. at Becht Engineering Co., Inc.
The release of API RP579 will bring about some changes to other existing API standards. The plan is to offer an integrated suite of API standards, where information is presented once and the other documents refer and are linked to that information. |
|
May/June 1996 Inspectioneering Journal
By Walter G. Reuter at INEL
The U.S. Department of Energy's Idaho National Engineering Laboratory (INEL) has a substantial interest in predictions for fitness-for-service as well as for lifetime extension. The ability to predict fitness-for-service is applicable to making initial lifetime prediction; making a repair, replace, or continue to operate decision when a defect is found that exceeds applicable codes and evaluating the ability to extend the lifetime of structural components. |
|
November/December 1995 Inspectioneering Journal
By Ted L. Anderson at Quest Integrity Group
An inescapable law of nature is that engineering materials contain flaws. Perfect materials and welds simply do not exist in the real world. A newly fabricated pressure vessel, for example, contains numerous imperfections and will probably degrade further in service. |
|
November/December 1995 Inspectioneering Journal
By Richard S. Boswell, P.E. at Stress Engineering Services, Inc.
Evaluations of aged and critical service vessels such as FCCU's and Delayed Cokers have been aided by the addition of two physical measurements referred to as structural characterizations. These are placed in perspective with the classic description provided by John Reynolds in his presentation of a multidisciplinary team effort in Fitness for Service (FFS) evaluations. |
