Emerson’s Fisher® Control Valve

Diagnostics Enable Operational Cost and Maintenance Time Reduction at Sweden’s Iggesund Paperboard

Emerson Process Management’s Fisher® control valve diagnostic technologies are being used for predictive maintenance to realise operational savings at Iggesund Paperboard, 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. It has an annual capacity of 330,000 tonnes of Invercote, a multilayered solid bleached board. In order to maximise 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.

"Almost ten years ago we realised that our methods of maintaining control valves and field instrumentation could be improved" said Peder Hägglund, the Technical Manager at the Iggesund mill. "Over time we have installed over 200 of Emerson’s FIELDVUE controllers and used the diagnostic capabilities extensively."

"We have worked with many end user organisations 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."

The FIELDVUE diagnostics are accessible online. The real-time predictive diagnostics give a fast and accurate insight into the health of the valves. 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 sites 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 can be used to determine control loop stability since both are indicators that the loop may be oscillating. 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. The maintenance department at Iggesund is increasingly employing these two alerts as they look to improve the overall performance of the mill.

"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 organisation to drive the necessary 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.

Extensive laboratory verification was performed on the Fisher 8580 to ensure reliability. Mechanical tests were conducted to determine cycle life, fatigue life, vibration resistance, temperature limits and pressure limits. In addition, tests were performed on materials for the Fisher 8580 valve body, disk, seals, shaft and bearings to assure resistance to conditions that could lead to deterioration in performance.

The new rotary valve can easily be installed in either a horizontal or vertical orientation with no detriment to performance or cycle life. This also enables left- or right-hand mounting of the valve actuator, allowing access for any installation.

The Fisher 8580’s disk design gives it an approximately linear flow characteristic to provide precise throttling control. The valve is offered with either a soft or metal seal, providing capability for enhanced shutoff. The interchangeable seal capability minimises parts inventory requirements.
To facilitate use in all world areas, the Fisher 8580 meets API, ASME, and EN standards. The valve body meets PN 10 through PN 40, CL150, and CL300 ratings. Face-to-face and raised-face dimensions meet EN 593, API 609, and MSS-SP68 standards.

Emerson Process Management, Tel: 0870 240 1978
Website: www.EmersonProcess.co.uk

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