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How Nova Scotia Power Implemented Its AM Program: Equipment Integrity Through PdM and RBI

How Nova Scotia Power Implemented Its AM Program: Equipment Integrity Through PdM and RBI by Warren Rodgers

How Nova Scotia Power Implemented Its AM Program: Equipment Integrity Through PdM and RBI

by Warren Rodgers

Image collage of NSPI

Aging assets, changing utilization, demographics and regulatory changes precipitated the need for an innovative and comprehensive asset management (AM) program at Nova Scotia Power Inc. (NSPI). Building on the elements of PAS55 and ISO55000, NSPI constructed a program for its power production business. The universal challenges of an aging infrastructure and workforce, along with industry specific and regulatory changes, demanded a shift in the company’s organizational philosophy toward asset management. Many of the company’s generating equipment assets are 30 to 40 years of age and had reached a point where new strategies were required. Among those strategies is the implementation of condition-based monitoring (CBM) techniques.

Many of the company’s generating equipment assets are 30 to 40 years of age and had reached a point where new strategies were required.

Predictive maintenance (PdM) and risk-based inspections (RBI) are an integral part of Nova Scotia Power’s asset management approach. These two elements are part of asset CBM strategies through, for the most part, noninvasive means. They provide information on deficiencies that feed the probability portions of risk assessments. Knowledge of a deficiency allows for an estimation of probability to timely mitigate prior to a failure, ultimately reducing impact and improving reliability.

PdM and RBI programs fall into the category of asset condition management and form elements within the overall strategic asset management program shown in Figure 1. It was important to NSPI to utilize common reliability tools and systems in such a way as to fit its organization’s capacity and need. For example, the augmentation of maintenance strategies using PdM and RBI facilitates reliability programs, but fits within functional maintenance strategies for rotating and static equipment. The key elements contained within each layer make up NSPI’s strategic asset management portfolio.

Figure 1: Elements in the approach to asset management at NSPI

In concert with the strategic asset management approach in Figure 1 is the mechanism by which system condition information feeds risk profiling for decision makers in Figure 2. Note the application of PdM/NDT on the lower right of Figure 2. As demonstrated in the figure, they form part of the overall maintenance strategy for any asset. An increase in deficiencies noted in the PdM or nondestructive testing (NDT) environment indicates an increase in risk influence based on worsening condition and the risk level, hence the decisions around mitigating that risk.

Figure 2: The mechanism for delivery of equipment risk assessment to identify high risk assets

CBM is defined by the more general analysis of equipment condition from many sources. NSPI equally takes on a number of forms for CBM, including automated monitoring, manual testing, predictive pattern recognition and the human senses. CBM for NSPI is also augmented by:

PdM: A third-party vendor with full-time equivalent (FTE) stations at NSPI plants supplies all vibration analysis, oil analysis, infrared (IR), ultrasound, electric motor testing and gas finder IR. Weekly deficiencies and recommendations are uploaded to the computerized maintenance management system (CMMS) program. By contracting out the service, NSPI aligns itself to best practices, imparts high quality assurance/quality control (QA/QC) and repeatable, consistent testing and data interpretation. Another important part of the relationship is access to specialized engineering resources required for special analyses.

Risk-Based Inspection: Starting with flow assisted corrosion (FAC) and high energy piping failure detection (HEP), separate programs are underway, partnering with third-party services to support program design, develop risk registers and inspection protocols. The deployment of FAC and HEP inspections resulted in NSPI adding over 10,000 measurement locations on piping in its stations alone. Future programs will include oil piping, tanks and vessels, and other static equipment that utilize NDT in a more classic sense.

Defining a purpose, protocols, methods and objectives for a fleet-wide program is the starting point to the delivery of these programs. By conducting gap analysis against those elements, NSPI created justification for a formal program that incorporates the needs of its regulators, insurers, plant staff, executives and leadership. Managing the development of a company-wide program is handled best as a project.

Starting with equipment and plant surveys allows for the design of practical routes and provides the service provider an opportunity to build its equipment databases matching NSPI’s. Technical applications followed with the appropriate alarms, trend requirements, measurement points and documentation of the process.

NSPI designed the RBI approach very similarly, but due to the nature of the nondestructive examination (NDE) environment versus the PdM one, it becomes necessary to treat the deployment a little differently. The primary challenge comes from the increased amount of measurement points required to track on any one system or component. For example, to check pipe thickness on an elbow, one may have to record up to 20 grid assigned points. To track each of those and repeat them in the future, they must exist as separated objects within a database. An example is the development of NSPI’s critical piping program. After the database was created, no less than 13,000 measurement points were generated for tracking.

Another primary difference between PdM and NDT is the nature of the frequency of most testing. For many assets, there is only a need to conduct NDE over many years or, in some cases like oil tanks, over decades. This means creating systems that are not reliant on people dependent procedures is necessary. Development of such processes requires more time and resources to design.

Once successful in addressing the plant and business unit differences, creating a business accepted strategy and objectives puts you most of the way there. The technical details in the program must be documented and become standards for the organization. This way, as people change roles, the processes will be consistently applied. The system, program and the processes must be measured with well-planned key performance indicators (KPIs) and open for continuous improvement.

Figure 3: The process for delivering a found deficiency to the CMMS/business unit

Continuous improvement is a hallmark of any successful business model. Allowing room for growth and meeting the ever changing expectations of business is built into the program at NSPI. The primary method is through formal, regularly planned meetings between the contract administrators on both sides to cover such topics as safety, operations, budgeting, technical issues and staff.

These mechanical integrity programs have gained acceptance by demonstrating the successes of preventing equipment failures, making informed decisions and work management excellence. NSPI deploys a common monitoring strategy across a fleet, providing staff and management with measures of success over time and ultimately, informed decision-making.

Understanding the health of equipment is a growing challenge as assets age and utilization changes.

If a business is not prepared to open up the program occasionally to look beyond its own boundaries, it will become stagnant and ineffective. Understanding the health of equipment is a growing challenge as assets age and utilization changes. Since the 2012 deployment, NSPI has generated, on average, over 850 deficiencies per year in the fleet and direct many resources and funding in the form of maintenance dollars or capital projects where they are needed most. By deploying rigorous and comprehensive PdM and RBI based programs, NSPI ensures that the overall asset management program will meet these challenges and others in the future. Success hinges on a good foundation, understanding the needs and differences between RBI (NDT) and PdM tools and techniques, advancing technology, inspiring change and striving for continuous improvement.