Every shutdown is a major investment of time and resources, but can be optimized using the latest tools and extensive maintenance expertise.
With three pulp mills in Chile, Empresas CMPC S.A. is the world’s fifth largest producer of pulp. Its Santa Fe Mill produces bleached eucalyptus pulp on two fiber lines. When preparing for a shutdown of fiberline 2 a few years ago, the mill entered into a predictive maintenance contract with Metso’s local service center for help in identifying which of the many valves needed service.
Altogether 74 control valves were identified as critical use, and Metso service personnel downloaded the performance data with the Metso FieldCare condition monitoring software three months before the shutdown. All the valves selected had been equipped with Neles® ND9000™ intelligent valve controllers when the line was built four years earlier.
“This predictive work helped to reduce the number of valves to be maintained and reduce the time invested by the planning personnel for this task,” says Javier Gonzalez, Electrical & Instrumentation Superintendent at CMPC Santa Fe.
Only 10% of the valves needed extensive work
Of the 74 valves, FieldCare showed that seven needed to be taken out for workshop maintenance and nine more required only minor servicing. Metso service personnel worked together with the mill to develop the list of spare parts needed for shutdown. This list helped to reduce the spare parts cost, previously purchased based on historical data.
As a comparison, on line 1 with older valve positioners, the mill’s maintenance department took out all 80 critical valves from the process because of the lack of accurate knowledge of their condition.
Metso’s predictive maintenance resulted in substantial savings on line 2 by eliminating unnecessary assembly and disassembly work and reducing the man-hours required during the shutdown. Javier Gonzalez continues, “It is necessary to add also the time and administrative work that was reduced related to spare parts purchases, due to the analysis and the improved delivery time of these items due the service contract.”
Less variability saves the environment – and money
Operating according to the continuously tightening environmental laws and regulations is one of the many challenges at today’s pulp and paper mills. Metso’s valves and intelligent positioner solutions enable pulp and papermakers not only to improve their environmental performance but also to gain significant financial benefits.
For example, a pulp mill in Courtland, Alabama, USA, was able to reduce its carbon footprint by 160 tons just by improving the control performance of its processes. When an oversized valve was replaced with a better-suited Metso valve and an intelligent valve controller, process variability decreased, saving 0.43 tons of caustic every day and 150 tons annually. The increase in profit through savings in caustic consumption amounts to approximately USD 48,000 per year.
Ecoefficiency stands out
Metso’s flow control products are safe, durable and ecoefficient. They are manufactured with minimized use of raw materials and energy, and are designed to eliminate emissions.
So much more with intelligent diagnostics
To keep pace with – and actually one step ahead of – the industry’s needs, Metso’s technology know-how has expanded from reliable, high-quality valve solutions to a broad range of intelligent valve controllers and software solutions.
Intelligent valve controllers improve the control of industrial processes. They maximize the availability of valves and minimize the variability of control loops, in addition to increasing and maintaining mill safety. High availability and easy interpretation are the key success factors in effective data analysis.
Metso Valve Manager™ takes predictive control valve maintenance to a new level
One of the latest innovations is Metso Valve Manager™, representing 3rd generation diagnostics. It takes predictive control valve maintenance to a new level by making the available information more user friendly and more easily understandable. This, in turn, improves maintenance efficiency and process performance as well as brings significant cost savings.
Valve Manager™ is capable of processing the collected diagnostics information to visualize the condition of the valve in question with five different indices: control performance, valve condition, actuator condition, positioner condition and the condition of the operating environment. With this information, maintenance managers, engineers and process operators are capable of making educated decisions concerning the control valve maintenance without in-depth valve know-how.
Unexpected shutdowns can be avoided and the control valve performance can be maintained at an optimum level by continuously monitoring the condition of the installed base at the mill and by taking the necessary preventive actions based on the available diagnostics information. Also, with the help of the diagnostics, the available maintenance resources can be more efficiently allocated during shutdowns.
3rd generation soon also for on-off and ESV valves
Currently, Metso is developing its valve solutions further to bring these features available for the on-off and ESD valves as well. The technology benchmark devices on the on-off side, such as Metso’s SwitchGuard™ intelligent on-off valve controller, already include diagnostics features that are especially designed for on-off applications.
Text by Marjaana Lehtinen
Published in 2/2013 Results automation magazine as part of 'Reliable valves increase process efficiency and lower total costs'.