Why develop integrity operating windows?
- New damage mechanisms may be introduced when changes to operating conditions affect key process variables, which can dramatically affect the remaining life of an asset.
- Corrosion rates may accelerate due to crude slate changes or velocity changes, and their effect on the asset may not be recognized until the next scheduled inspection - even if based on risk.
- IOWs identify possible process changes and operating conditions that can affect remaining life and the actions required to mitigate any newly imposed risk.
- Integrating IOWs and real-time corrosion models with your RBI program facilitates the right decision-making-process when these changes occur.
What the standards are saying:
- API RP 580 Section 6.4 - "It may be worthwhile to monitor key process parameters to determine whether operations are maintained within boundaries."
- API 510 Section 6.2 - "The likelihood of failure assessment should be repeated each time equipment or process changes are made."
- API 584 - This second draft of best practices and guidelines for IOWs is under review and has been under development for several years.
What the Owner Operators want:
When considering the implementation of IOWs, prudent Owner Operators want to ensure that the resulting implementation tracks the ongoing development of these standards and is aligned with other industrial standards and recommended practices, such as API 510, APII 570, API RP 571 thru 585, and API STD 653, as well as any in-house standards and risk policies resulting from the implementation.
What is the process of Integrity Operating Window development?
Asset Optimization Consultants implements IOWs following a series of work process steps in line with the Owner Operators best practices. When these are unavailable, AOC has work processes and procedures to augment or deliver new, corporate IOW guidelines. The RBI plan and corrosion study are based on historical operating and inspection data and assumes the assets are all operated within the design specification. With the development of IOWs, your people are equipped with a proper decision-making process to handle changes that occur to your operating conditions. Over time, the life of your asset remains protected.
In general, the process involves:
- Facilitating an IOW review team made up of key stakeholders from the Owner, including inspection, reliability, corrosion engineering, materials engineering, instrumentation, process, operations and maintenance.
- Collecting Data - A myriad of data is required, ranging from process documentation, corrosion studies, and maintenance histories to planned changes in operations and feedstocks. If these are not available, corrosion loops are established as well as identification of required instrumentation for IOW parameters.
- Prioritizing IOWs - The review team will identify and prioritize target IOWs, which can be based on numerous characteristics, loss of reputation, production loss, level and location of risk and consequences as indicted in the RBI study, and on health, safety or environmental impact. Likelihood can be determined from the RBI study or simply the timeframe for an unacceptable event if the process variable is exceeded.
- Recommending IOWs - Each IOW includes a recommended inspection/action response on the part of the operator/inspector/maintenance/reliability engineer.
- Implementing remedial actions - When an IOW is exceeded during operation, the defined personnel can implement the indicated remedial action per the IOW. This action can also include notifying the Reliability Engineering Department, which may need to determine whether additional action, such as a fitness-for-service review, if necessary.
- Integrating IOWs - IOWs should be integrated with other programs within the facility, including but not limited to RBI or inspection program, MOC (management of change), PHA, and of course, Operations.