Integrity Operating Windows (IOWs) are sets of limits used to determine the different variables that could affect the integrity and reliability of a process unit. Put simply, IOWs are the limits under which a machine can operate safely. Working outside of IOWs may cause otherwise preventable damage or failure. For this reason, it's incredibly important to be aware of the IOWs for each machine that is in operation.
A common example of things IOWs can include is temperature limits on furnaces. Since leaving furnaces too hot can cause ruptures or damage to the metal, upper limits need to be set on the temperatures it’s allowed to work at. If the temperature is exceeded, then an operator should be given a certain amount of time to get it back under the limit.
It is important to develop limits for every possible damage mechanism that is likely to affect a component. This way the working within the limits for the machine will be able to prevent most likely types of damage that might affect it.
To start with, for every piece of equipment, an IOW plan should be created. A proper IOW plan will contain information for operators and others on how to respond to IOW alarms and variances along with how quickly they need to respond. It will need describe what process monitoring techniques and process sampling will be needed to provide assurance that the process stays within the established IOW limits.
API RP 584, Integrity Operating Windows (IOWs), is a standard by the American Petroleum Institute which covers IOWs and related topics. This standard deals with the parameters that should be established and the data required in order to set up a proper IOW plan. It talks about the different types of IOWs used for process units. It covers risk ranking, documenting, implementing, reviewing, changing, and updating IOWs.
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November/December 2018 Inspectioneering Journal
By Tim Hill at Quest Integrity Group
This article provides an overview of the key components in establishing IOWs, the levels of IOW limits, and the basic principles and application of API Recommended Practice 584 to achieve reliable fired heater performance. |
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November/December 2018 Inspectioneering Journal
By John Campo at PinnacleART
This article walks you through a three-step approach, while providing different scenarios, for identifying and proving the value of reliability improvement initiatives. |
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September/October 2018 Inspectioneering Journal
By Yousuf Hasani at Continental Marine Energy Sdn. Bhd. Malaysia
This article presents a management approach for the implementation of Integrity Operating Window (IOWs) under API RP 584 and discusses the IOW planning process and how input from other programs like RBI and Corrosion Management Plans is critical to establish appropriate limits. |
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March/April 2018 Inspectioneering Journal
By Cesar Espinoza at PinnacleART, and Sudhakar Mahajanam at PinnacleART
As RBI continues to proliferate across industry, there are still those that are reluctant to transition from a time-based to risk-based inspection approach - especially in the upstream oil & gas business. These 4 benefits might help to lessen the resistance to RBI. |
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September/October 2017 Inspectioneering Journal
By Daniel Cypriano at Petrobras, and Henrique Ventura at Petrobras
Although value-drivers often differ between facilities, all can agree that effective asset management strategies should lead to better decision making. In this case study, the authors detail how process-based risk management strategies can make for improved use of equipment. |
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March/April 2017 Inspectioneering Journal
By Fernando Vicente at ABB, and Laza Krstin at ABB
Myths, challenges, and good practices related to process piping integrity management activities that help inspection and maintenance managers make the right decisions to develop cost-effective piping inspection plans without compromising the asset’s reliability or performance. |
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March/April 2017 Inspectioneering Journal
By A.C. Gysbers at The Equity Engineering Group, Inc.
Integrity Operating Windows (IOWs) have a subset of operating variables that are important for degradation monitoring, but may not have direct operational controls. Per API RP 584 Integrity Operating Windows, these are known as IOW Informational Limits, which are often neglected or misunderstood by operations or technical personnel within a plant. |
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March/April 2017 Inspectioneering Journal
By Vibha Zaman, P.E. at Asset Optimization Consultants, and Leomar Penuela at Asset Optimization Consultants
This article discusses the use of the RBI methodology supplemented by a well-designed IOW program to assess and manage aging in fixed equipment and piping in hydrogen generation units. |
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January/February 2017 Inspectioneering Journal
By Israel D. Martinez at ORPIC
Evaluating remaining wall thickness of an asset is not enough to ensure its continued safe operation. Proactive strategies should be implemented to assess the entire environment affecting an asset’s condition, including the development of more effective inspection plans. |
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September/October 2016 Inspectioneering Journal
By John Reynolds at Intertek
Did you ever wonder where you fit into the entire hierarchy of a fixed equipment asset integrity management (FE-AIM) program? Or who is responsible and accountable for what aspects of FE-AIM at your site? All the way from top management down to those doing the work at the field level? That’s what I will try to address in this article. |
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January/February 2016 Inspectioneering Journal
By Greg Alvarado at Inspectioneering Journal
The enormous decline in oil prices over the past 14 months has definitely slowed projects and changed the energy and production landscape. Despite this, refineries, petrochemical plants, and chemical facilities must continue to run safely, responsibly, and reliably. |
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September/October 2015 Inspectioneering Journal
By Marc McConnell, P.E. at Pro-Surve Technical Services, and Nolan L. Miller at SASOL North America
If we could measure, understand, mitigate, and most importantly, control corrosion, we can do a better job of keeping the product in the pipes. To accomplish this task, we needed to know what is causing the corrosion and how to control it. |
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November/December 2014 Inspectioneering Journal
By Alphonse W. Hegger Jr., P.E. at Stress Engineering Services
Today, more than ever, refinery operators are focused on maintaining safe operations for their employees and extending the life cycle of valuable operating equipment to optimize efficiencies and avoid expensive unforeseen shutdowns. When process unit corrosion assessments, RBI methodologies, and IOWs are properly integrated into refining operations, the result is improved safety and longer run times. |
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September/October 2014 Inspectioneering Journal
By John Reynolds at Intertek
Based on my 45+ years of experience working with fixed equipment mechanical integrity (FEMI) issues in the refining and petrochemical processing industry, this article summarizes what I believe are the top 10 reasons why pressure vessels and piping systems continue to fail, thus causing significant process safety events (e.g. explosions, fires, toxic releases, environmental damage, etc.). |
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July 28, 2014 By John Reynolds at Intertek
Fixed equipment mechanical integrity (FEMI) failures are not caused by damage mechanisms; rather, they're caused due to failure to create, implement, and maintain adequate management systems to avoid failures. Nearly all failures that have occurred in our industry could have been avoided if these human systems were more robust and sustainable in providing the primary layers of protection for FEMI. |
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June 2, 2014 By John Reynolds at Intertek
Three new API standards have been published, and one has been revised and updated to a new edition. The standards are described in this post. |
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January/February 2014 Inspectioneering Journal
By Mike Urzendowski at Valero Energy
The intent of these two articles is to share lessons learned from recent experiences setting up a comprehensive HTHA review process across multiple refineries, and to help other operators define and mitigate the HTHA risk to an acceptable level. |
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October 14, 2013 By John Reynolds at Intertek
There are 10 essential Management Systems (MSs) needed for an effective PEI program that can achieve excellence. These 10 PEI MSs contain all the necessary information that describe what needs to be accomplished, and how to accomplish it, in order to achieve success in PEI. |
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October 7, 2013 By John Reynolds at Intertek
Knowing what needs to be accomplished in order to achieve excellence in pressure equipment integrity (PEI) is one thing, but knowing how to organize it all for success is quite another. |
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September 23, 2013 By John Reynolds at Intertek
These posts came about because, from time to time, I’m asked why some operating sites don’t seem to pay adequate attention to the need to protect and preserve pressure equipment integrity (PEI). Too often a few sites don’t seem to “get it” until they have a major process safety event associated with a failure of pressure equipment. When that happens, they are suddenly on... |
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July 22, 2013 By John Reynolds at Intertek
Without doubt management needs to ensure that the appropriate resources (human and budgetary) need to be provided for corrosion control and prevention. The C/M engineer/specialist or other responsible party needs to assure that management is advised annually at the appropriate time what resources will be needed for the next budget cycle. |
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November/December 2010 Inspectioneering Journal
By John Reynolds at Intertek
High Temperature Hydrogen Attack (HTHA) is a long known and still occurring degradation issue for fixed equipment construction materials in the hydrocarbon process industry where hydroprocess plants (hydrogen plus hydrocarbons) are in service. Though HTHA failures in these units are the focus of this article, it is important to recognize that HTHA damage can also occur in high pressure boiler tubes, hydrogen producing units, synthetic gas units, ammonia plants and other equipment where hydrocarbons may not be involved but high temperatures are involved. |
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March/April 2010 Inspectioneering Journal
By John Reynolds at Intertek
This article in the series will focus on two more of the necessary MSs for achieving excellence in PEI: Integrity Operating Windows (IOWs) and Management of Change (MOC). |
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March/April 2005 Inspectioneering Journal
By John Reynolds at Intertek
One of the more important uses of the 99 Diseases of Hydrocarbon Process Equipment is to determine how to safely operate process pressure equipment. Such a work process thereby minimizes the impact of any potential degradation mechanisms (the 99 Diseases), by establishing the appropriate boundaries for long and short-term safe process operation. Such boundaries are called Integrity Operating Windows (IOW's). |
Many refining, gas processing, and petrochemical plants have already identified the need to define Integrity Operating Windows, but most are still unsure how to extract the most value from them.
