Back in March, your regular blog host Jim Cahill wrote about how the Fieldbus Foundation incorporated the NAMUR end-user association’s new recommendations for device diagnostic functions and status reports, known as NE 107. The result is the Fieldbus Foundation’s FF-912 diagnostics profile specification.
But what does FF-912 do for manufacturing facilities? In a recent article for Control Engineering Asia called “A Complete Turnaround,” Emerson’s Jonas Berge says it’s an important part of broader changes that herald “a new era in intelligent device management.”
Plants can make intelligent device management software part of asset management systems a natural part of everyday operations for years to come by following a simple process from audit, device alarm rationalization, work practice review, and training.
Of course, that’s because NE107 and FF-912 are propagating this alarm rationalization industry-wide.
The work processes have been established and standardization work has been started by an ISA committee – ISA108. This committee will define standard templates of best practices and work processes for design, development, installation and use of diagnostic and other information provided by intelligent field devices in the process industries.
So, what will this all do for daily plant maintenance? Well, for starters …
Device diagnostics can be configured to one of the status categories in the NAMUR NE107 recommendation: Failed, Off Specification, Maintenance Required or the slightly different Function Check. This simplified status signal makes device health easy to overview and is the basis for routing device diagnostic alarms to the right person regardless of communication protocol used by the device.
NE107 also defines standard icons and colors to signal the device status in the dashboard part of the device description file. Such a dashboard can be displayed both in the intelligent device management software as well as on the operator console.
The criticality of a particular loop and its devices device is application specific. The device alarm rationalization process ranks criticality based on process impact severity and allows maintenance to better prioritize their work. This requires engineering at system implementation.
And with some changes to work processes, “central ‘desktop maintenance’ planning can become a reality,” as Jonas Berge says.
The daily maintenance routine must start with checking the intelligent device management software alarm summary first for a prioritized listing of devices in need of maintenance, to know which devices are in most urgent need of service that day, and to schedule the day’s work accordingly.
For instance, device self-diagnostics such as built-in continuous valve friction monitoring in a valve positioner reports to the intelligent device management software when friction is high and the valve maintenance should be planned.
And of course, plant turnarounds.
For a plant turnaround, the planning procedure should be to check the software first, well before the turnaround, to determine which valves and which flow meters really need to be pulled out for maintenance or sent for calibration, and which ones do not.
Thanks to valve signature diagnostics in valve positioners and meter verification in flow transmitters, it is possible to tell which valves have suffered wear-and-tear and which flow meters have drifted. These tests are non-intrusive and can be done while the plant is still running.
Using this methodology, the scope of the turnaround maintenance can be reduced, freeing up resources for other turnaround tasks and also shortening the duration of the outage. The serious cases are prioritized and done first, while the rest are done if there is time left over. Savings from not wasting time and resources on valves and flow meters not in need of service include costs for cranes, hoists, scaffolding, fitters, riggers, instrument technicians, plus insulation and other material.
Jonas adds plenty more about basic system requirements, keeping device diagnostic software up to date, detecting abnormal process conditions using process-connection diagnostics, straightforward user interfaces, and more. Check it out!