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Case Study: Improvements in a Piping Program Yield a 3X ROI

Learn how we implemented a piping reliability program that turned a compliance project into a 3X Return on Investment (ROI) for a refiner. The implementation of this program was an important, calculated step in the operator’s evolution toward an effective RBI program.


The impact of LOC events can range from a loss of profit to serious Health, Safety, and Environment (HSE) consequences. A strong, integrated mechanical integrity (MI) program can help facilities satisfy compliance regulations, improve reliability performance, and prevent LOC events from occurring. Having standardized, scalable asset strategies that strategically target inspections will help facilities proactively identify potential risks, understand those risks and drivers, and prevent LOC events before they occur.

The Challenge

This refiner experienced two massive LOC events at multiple sites, which resulted in astronomical expenses and compliance violations. One of the events was caused by a leak in a section of insulated carbon steel piping that had thinned over time due to corrosion. As a result of the event, the refiner was required to implement inspection strategies across various piping classes to prevent future leaks.

Before the events, the refiner struggled to proactively identify and mitigate LOC risks and lacked an integrated, holistic MI program. Additionally, there was no formal system in place to flag assets that violated the acceptable range for process operating conditions. Further, some sites relied more heavily on the knowledge of experienced materials engineers and inspectors than others, and as a result, the quality of document organization varied by site.

To address these challenges and meet compliance, the operator needed to develop and implement a series of inspection strategies across its fixed equipment and piping that would enable employees to proactively identify, manage, and mitigate LOC risks at a system level and satisfy Recognized and Generally Accepted Good Engineering Practices (RAGAGEP). Specifically, these strategies needed to include a defined set of integrity operating windows (IOWs), change management criteria, and processes that would guide when to act on assets before they violated the acceptable process condition ranges.

Initially, the refiner attempted to implement these strategies on its own and quickly realized it needed additional resources and MI expertise. Additionally, some site leadership worried that they would not have the necessary resources to keep up with the increased level of inspection required when the initial and recurring inspection intervals started to overlap. Ultimately, Pinnacle was brought in to implement a standardized program that would strategically target areas to inspect and could be replicated across all sites.

Pinnacle's Solution

As part of the solution, the Pinnacle team worked with the refiner to create a set of corporate piping standards. These standards, which were rolled out across four sites, focused on improving the operation and maintenance of the operator’s fixed equipment and preserving the piping’s pressure boundaries. The primary goal of the implementation was to provide the refiner with standardized drawings that could be leveraged by multiple sites and disciplines, including inspectors, processes, designs, and turnaround planning.

The scope of the project included the following:


The objective of this step was to create a solid, system-level foundation for the inspection strategies in an expedited timeline. During this stage, the team developed a deep understanding of the operator’s piping, operational elements, and equipment by gathering and systemizing critical asset data from the piping process flow diagrams (PFDs), piping and instrumentation diagrams (P&IDs), and process data.

System-Level Damage Mechanism Identification (DMR) & IOWs

After all critical data was gathered from existing documentation, the Pinnacle team identified the damage mechanisms and associated inspection strategies that could apply to those systems. Each system had specific damage mechanisms based on stream chemistry, materials of construction, and operating conditions. In addition to identifying whether the damage mechanism was local or generalized, the strategies specified whether the failure mode was cracking or thinning and the type of LOC event that was likely to occur if the asset failed.

After the system-level damage mechanisms were assigned, the team implemented a series of IOWs to help the facility identify potential damage mechanisms and the associated parameters that cause the damage.

With an IOW system in place, operators will receive an alert when the IOW parameter exceeds or crosses a specific operating threshold and can then adjust the facility’s conditions to bring the parameter back into the normal operating range, if feasible, or take other action as appropriate. The series of IOWs was prioritized by the level of urgency and classified the time and magnitude of potential failure. Some parameters, like sulfur content or temperature, may be inherent to the process. Regardless, to attain the desired reliability, remedies will be identified and recommended appropriately.


The objective of this step was to conduct a more detailed analysis of the operator’s piping. After identifying the damage mechanisms and implementing IOWs at the system level, the team took a deeper dive into specific circuits, which enabled a deeper and more accurate understanding of specific process conditions and their potential impact on materials of construction and damage mechanisms.

For this project, the established systems were further broken down into circuits based on relevant considerations such as temperature, fluid velocity, and piping material.

ISO Correlation

The next task involved taking the circuits from the previous circuitization step and translating them to the inspection drawings, allowing inspectors to identify the start and stop points in the field and correlate CMLs to the circuits.  Additionally, during circuitization and ISO correlation, the team validated, defined, and marked deadlegs of potential concern within the systems.

Circuit-Level DMR

Damage mechanisms for each circuit were identified based on the materials, design and operating properties, and practices. The mode of damage, e.g., localized versus generalized corrosion, cracking, metallurgical, mechanical, creep, and brittle fracture, were considered along with their potential damage severity.

CML Optimization

Next, the Pinnacle team completed CML Optimization, which included the identification of potential CMLs and selected CMLs:

  • Potential CMLs (PCML): Understanding and leveraging the damage mechanisms identified during the circuit-level DMR and IOW meeting, the team identified every PCML location per associated inspection strategy development.
  • Selected CMLs: Once all PCMLs were placed, the team totaled the counts and applied inspection requirement guidance, which leverages pipe class and damage mechanism susceptibility.
  • CML Numbering and Datamining: Once selected CMLs were finalized, the team numbered them per circuit according to flow order. Flow order is important in understanding and using the system dynamics. Key information was populated for each selected CML, which included damage mechanism morphology, characteristic locations of damage (e.g., weld, HAZ, base material, elbows, 12 o’clock position, ID or OD, extrados versus intrados, etc.) diameter, component type, pipe schedule, nominal thickness, and corrosion allowance. This information was utilized to determine the proper methods of inspection (e.g., radiographic or ultrasonic), which would be captured in the CML nomenclature as displayed (i.e., consistent with) in the refinery’s inspection data management system (IDMS) and piping isometrics. This information was also confirmed for accuracy or flagged for an update when a selected CML coincided with an existing CML.

Inspection, Testing, and Preventive Maintenance (ITPM)

The team conducted a high-level review of the elements required for an inspection per circuit. During this review, the team detailed crucial information, nondestructive evaluation (NDE) types, selected CML counts, and deadlines/inspection intervals which gave inspectors a chance to review the drawings and provide feedback. The team also aligned its inspection efforts so that previously planned activities could be expanded to acquire readings and groups of CMLs could be evaluated together to avoid large numbers of CMLs coming due for inspection at the same time.

Asset Strategy

A formal asset strategy report was delivered during the project. These asset strategies detailed the necessary resources needed to complete the work and any potential issues that could occur. Most importantly, these strategies illustrated how inspections would be affected by the changes in inspection methods and pipe class. The report also included summaries of the new CMLs and NDE inspection methods.

IDMS Update

The Pinnacle team then uploaded the information into the IDMS. This step will help the team better maintain its asset history and will create standardization across multiple sites. This database will include all validated information and assessments, previous inspection results and summaries, and will alert facility leadership of future inspection dates.


Evergreening is one of the most important aspects of a MI program. During this stage, the Pinnacle team worked with the site’s employees to sustain the MI program over time. The evergreening phase consists of helping the sites manage any changes and evaluate the above steps for potential changes that need to be implemented. For example, one site may need to replace a carbon steel circuit with stainless steel. For that change to be implemented smoothly, the team would review existing damage mechanisms and susceptibilities and likely need to update damage mechanism assignments, exclusions, and susceptibilities. Additionally, the team would rework the placement of potential CMLs and would need to check the selection requirements based on the new information. Following that, the team would rework the selection, update the ISOs with the new CML locations and names as well as other critical fields, and would ensure these updates are captured in the IDMS.

Additionally, the program implementation established a systematic inspection strategy that can be replicated across additional sites and equipment types. The standardization of inspection strategies at these four sites reduced the operator’s CML count by 27.4% and enabled the operator to proactively identify, manage, and mitigate LOC risks, helping the operator meet compliance.


The program implementation yielded a 3X ROI for the operator. The inspection strategies cost approximately $100MM to implement and the resulting deliverables identified over 200 integrity threat recommendations (ITRs). Since these ITRs were identified prior to causing failures, the operator was able to prevent the significant costs that would occur if the piping failed. The operator calculated that if 50% of these threats had resulted in failure events, the probable cost of incidence (COI) would have totaled hundreds of millions of dollars.

Additionally, the program implementation established a systematic inspection strategy that can be replicated across additional sites and equipment types. The standardization of inspection strategies at these four sites reduced the operator’s CML count by 27.4% and enabled the operator to proactively identify, manage, and mitigate LOC risks, helping the operator meet compliance.


The implementation of piping inspection strategies helped the refiner take a step towards having a more integrated, holistic MI program. With these new strategies in place, the operator is able to better focus its approach to risk management across various classes of piping and will ensure that these sites meet compliance.

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