Unplanned valve-related shutdowns have been eliminated, operational costs reduced, and maintenance time cut at Sweden’s Iggesund Paperboard by implementing predictive maintenance. Emerson Process Management’s Fisher® control valve diagnostic technologies are being used at the mill, a business of the Swedish Holmen Group.
The Iggesund mill is one of the most advanced, fully integrated pulp and paperboard mills in the world, with an annual capacity of 330,000 tons of Invercote, a multilayered solid bleached board. In order to maximize availability, the plant has moved away from scheduled maintenance of control valves to the predictive maintenance approach.
At the mill, diagnostic information from Fisher FIELDVUE® digital valve controllers is delivered to Emerson’s AMS® Suite predictive maintenance software for access by plant personnel. The AMS ValveLink® software application delivers the valve health data, enabling plant personnel to eliminate unplanned shutdowns, reduce inventory of new valves and spare parts, and decrease maintenance time.
Recognizing a Need for Improvement
“Almost 10 years ago we realized that our methods of maintaining control valves and field instrumentation could be improved,” said Peder Hägglund, technical manager at the Iggesund mill. “Over time we have installed over 200 of Emerson’s FIELDVUE controllers and used the diagnostic capabilities extensively.”
FIELDVUE diagnostics are accessible online. The real-time predictive diagnostics give a fast and accurate insight into valve health and the ValveLink software can be used to quiz the FIELDVUE devices for additional information or to run advanced diagnostic tests. Travel Deviation alerts are a primary indicator of control valve problems.
“The Travel Deviation alert is triggered when the control valve has not moved to its required position within a certain period of time,” said Tommy Nielsen, the site’s control valve specialist. “This alert can indicate many potential faults, such as an increase in friction, air leaks, mechanical faults, or a physical blockage. Other alerts that we find most useful are the Cycle Counter and the Travel Counter.”
The Cycle and Travel Counter alerts, both indicators that the loop may be oscillating, can be used to determine control loop stability. Oscillations can cause poor control and can, in extreme circumstances, lead to the loop being put into manual control. Poorly tuned loops can lead to quality issues, excessive raw material usage, an increase in energy consumption and premature valve wear. Iggesund’s maintenance department is increasingly employing these two alerts as they look to improve the mill’s overall performance.
Teamwork, Innovation Keys to Success
“The success of control valve diagnostics at our mill can be attributed to many factors,” continued Hägglund. “We have a genuine interest in innovative technologies, an enthusiastic team who have perfected the use of online control valve diagnostics, and the success they experienced has motivated people throughout the organization to drive the necessary improvements.”
“We have worked with many end-user organizations across all industries, helping them to develop operating procedures around control valve diagnostics,” said Wendy Nancarrow, the European director for Emerson’s Fisher valve instrumentation business. “Of all the companies we have worked with, we believe that Iggesund are one of the world leaders in the use of online control valve diagnostics technology to drive plant performance improvements.”
Fisher valves with FIELDVUE digital valve controllers are key components of Emerson’s PlantWeb® digital plant architecture that networks process automation systems and instrumentation to provide efficient operations and predictive technology-driven maintenance for process facilities worldwide.