This guest blog post was authored by Ian Verhappen, an automation industry consultant and chairman of the ISA103 Standards Committee for the FDT Group, in conjunction with an ISA co-hosted webinar on proactive condition-based maintenance strategies.
According to industry estimates, most installed measurement instruments are “smart.” Smart devices provide more than just the process variable measurement using the 4-20mA signal. In order to maximize your investment in smart measurement devices, better manage your operations, lower your operating costs and improve plant reliability, intelligent information from those devices should be available to operators, technicians and other specialist who can put it to work to better manage the operation. Because without a better view of the diagnostic condition and performance status of your devices, you have limited ability to take proactive action that can have significant, positive impact on plant reliability.
Intelligent Device Information
Smart measuring devices can communicate many categories of information using different field communication protocols. In addition to multiple measurements (with newer devices reporting as many as eight process variables), devices can report important device diagnostics and process information.
Think of the usefulness of the diagnostics in your automobile or your computer: The diagnostic system in your automobile performs hundreds of measurements and adjustments, continuously, to provide a quick indication of the status and potential availability (or lack thereof) of your car. Using device configuration or asset management applications, you can get the same type of diagnostic warnings of device malfunction or status from your installed smart instrumentation.
By improving the view of the condition of a device, you take the important step to make your smart device a specialist in your quest to improve plant reliability. We all know that you cannot continue to do “business as usual” and expect different results. With minimal or non-existing upgrade or process improvement budgets, there is the need to better utilize installed assets. And, rather than chasing arbitrary or forced cost cutting campaigns, focus on getting and using the stranded information sitting in your smart measurement assets.
Pending diagnostic warnings, however, are only helpful if a warning is investigated, and appropriate action is taken. Your smart measurement device has the ability to provide valuable diagnostics information − but it’s valuable only if you’re checking to see if there is a problem. A PC-based device configuration and management application is a cost-effective solution providing remote access needed to review and analyze potential process problems thus helping you avoid unplanned situations.
Move From Reactive To Proactive
Many newer or updated control and asset management systems enable intelligent device diagnostic information to be accessible and available for immediate use. For those that don’t, there are many different cost-effective products that make access to intelligent device information possible. This diagnostic information enables you to change your maintenance activities from reactive − work on what’s broken − to more proactive or even predictive activities, such as fixing small problems before they turn into bigger problems that may cause an unplanned outage or shutdown.
Imagine the benefits of using real-time device diagnostics to reduce the number of trips to the field, prevent an unscheduled shutdown or reduce the length of a scheduled shutdown. Whether you are part of the reliability, maintenance, process improvement, management or other plant function, putting this valuable information to work can produce big results with relatively small investments and low-risk.
By accessing more information from your smart measurement device than just the process measurement, you are changing how you view that device - making smart installed assets your specialist in the quest for improved plant reliability. Why? Because maintenance costs are driven by device and plant reliability. The higher the reliability, the lower your maintenance costs. Likewise, the lower the plant reliability the higher your maintenance cost (as measured by overall equipment effectiveness or asset utilization) Improved plant reliability typically translates into increased capacity, product quality, availability and even safety!
A Reliability Specialist
In 2002, the MOL Group’s Danube Refinery in Százhalombatta, Hungary, set out to improve profitability using its installed smart technology and only three years later, decided to overhaul its maintenance systems with a new, unified asset management system strategy. The combination of the two has changed the way MOL runs maintenance, and the way it looks at diagnostic data.
The company connected many of the plant’s smart devices, such as control valves and instruments used in critical control loops, directly into the plant’s asset management system. This has resulted in an online diagnostic system in which instrument signals are directly connected to plant maintenance and control systems.
“On-line diagnostics provided by the these instruments does something more than preventive maintenance,” said József Bartók, automation engineer at MOL Danube Refinery. "This ensures the stable operation of the system and increases the precision of control.” Beyond fixing what breaks or keeping the plant running, a reliable, stable operation contributes to bottom-line profitability.
For example, when the head pressure control was slow on one unit, it led to the assumption that a valve was stuck and in need of removal and repair. But technicians, using on-line diagnostic tools, used device diagnostic data to interrogate the valve and found that the cause was damage to the current-to-pneumatic converter in the intelligent positioner − but not the whole valve. Operators put the valve in manual and the fix took a half hour of instrumentation work. This repair saved the plant at least two days of unscheduled downtime, worth at least $834,400.
Before using device diagnostics, about 60 percent of the control valves were selected for repair in a typical plant shutdown. While all faulty valves were likely corrected, others may have been removed unnecessarily due to a lack of data indicating the true health of the device. With device data, the company estimates average savings of $70,000 per unit, per shutdown; it’s no longer necessary to disassemble and repair failure-free control valves during a shutdown. Because their asset management systems were DTM enabled, they were able to work with different field communication protocols and have access to the predictive notifications they needed to avoid unplanned outages.
Having a better handle on valve performance also allows MOL to pull fewer valves at turnaround time, substantially reducing maintenance costs and shortening the time needed before production is resumed. "Ten years ago, we pulled all of the valves," said Gabor Bereznai, MOL instrumentation and electrical department head. "Now, we pull two dozen instead of 200, saving $20,000 to $70,000 per turnaround. The device configuration and management application provides fast detailed device checks with a visualized faceplate and a simple to understand device overview.” As shown in Figure 1, there is a significant reduction in the number of control valves that have to be removed, repaired and replaced during a unit turnaround.
Integrate Intelligent Device Diagnostics
The intelligence in your installed smart measurement devices might be one of the most under-utilized assets available in your plant today. By integrating the intelligent device diagnostics into an asset management or automation system, you begin the process of monitoring the device status allowing the opportunity to improve plant reliability. Using solutions available from your automation providers, you will identify minor problems before they become critical − lowering maintenance and operating costs and improving plant reliability.
So take the first step and make your smart assets your new reliability specialist. With device and asset management solutions that range from working with a single device (such as using a handheld or PC-based application) to a fully integrated smart device information implementation in your control, PLC or asset management system, the view of a more reliable plant will come into focus.
About the Author
Ian Verhappen, P.Eng., CAP, is a senior project manager at CIMA+ where he specializes in industrial communications networks, including Foundation Fieldbus technology; control system migrations/upgrades; process analyzers; sample systems; and oil sands automation. Ian, an ISA Fellow, has been involved in digital communications since 1994. He helped to install the first multi-vendor Foundation Fieldbus project in 1996. Since then, he has served as both a project engineer/designer and an external review consultant for a number of companies in pulp and paper, mining, food processing, water and wastewater, oil sands processing, petrochemical and refining industries. Ian is an active ISA volunteer leader, serving as Vice-President of ISA Standards and Practices and a former ISA District 10 Vice President. As a leader in automation practices, he has worked closely with the Standards Council of Canada and the International Electrotechnical Commission (IEC). He currently serves as Canadian Chair of IEC TC65, SC65B and SC65E. He is co-author of several ISA books, including A Guide to the Automation Body of Knowledge and Foundation Fieldbus. An inductee into the Process Automation Hall of Fame, Ian earned a bachelor of science degree in environmental science and a bachelor of chemical engineering degree, both from the University of Alberta.