The PM 1 pilot paper machine stands in the core of the competitiveness of the leading pulp and paper technology company Metso. The pilot machine is used to develop new papermaking technologies and to test the products of Metso’s customers. PM 1 is located at Metso’s Paper Technology Center in Jyväskylä, Finland, where Metso showcases its capabilities and competitiveness.

Metso is known worldwide for a culture of innovation and agility to adopt novel ideas that promise improvement. A rebuild of PM 1 in late 2009 well illustrates this culture. Metso was quick to accept a new product presented to them by Outokumpu, their long-time partner in stainless steel supply: lean duplex process pipes.

Outokumpu had recently introduced a comprehensive set of piping products in the company’s proprietary lean duplex grade LDX 2101®. The new products promised to Metso major material saving in the process pipes of PM 1’s former section, coupled with good corrosion resistance.

“When Outokumpu presented to us this new solution, we introduced it into our product development,” says Metso Procurement Manager Jari Mäntynen.

“The high strength of the duplex material translates into more lightweight process pipes, which again translate into increased cost-efficiency,” he elaborates on the benefits.

The former section of a paper machine. Courtesy of Metso

Metso relied on Outokumpu’s expertise on corrosion resistance and other know-how on welding, material handling and areas of application.

Mäntynen comments on the service provided by Outokumpu in the project: “We received good support from the start. Their people came to us, bringing us the information in person. Overall, we had good direct contacts with Outokumpu in this project.”

The pulp and paper industry is a heavy user of stainless steel, from pulp mill equipment to the wet end of paper machines. Metso and Outokumpu have a long history together in building industry-leading machinery and equipment from a wide range of Outokumpu stainless steel products, including shells for suction rolls, and plate and other flat products for headboxes, vessels and tanks.

Outokumpu’s duplex LDX 2101® has in recent years established itself as a competitive alternative to conventional, austenitic grades in pulp and paper processes owing to its many strengths in comparison: high mechanical strength, corrosion resistance close to that of austenitic 1.4404 (316L), high resistance to stress-corrosion cracking, and good mechanical properties. Duplex LDX 2101® can be successfully applied at most stages of pulp and paper making. It even replaces super-austenitic grades in pulp processes at high temperatures.

Outokumpu’s palette of LDX 2101® products has been complete save one key component: pipes and fittings. In autumn 2009, Outokumpu fulfilled this void, introducing Outokumpu Duralite™ Piping System products in duplex LDX 2101®.

“This is the last piece of the puzzle, which completes the picture,” says Jarkko Pajusalo, Outokumpu’s General Manager for the Pulp and Paper Segment. “We have made focused efforts to develop LDX 2101® applications for pulp and paper processes and finally, with the Duralite™ Piping System, our customers can take full advantage of duplex LDX 2101® in their processes.”

Sören Nytomt, an Outokumpu Application Engineer in Duralite™ solutions, lists the products’ benefits and properties:

“First, we now have a comprehensive set of lean duplex pipes and fittings available from stock.

“Second, the high proof strength of the duplex material enables up to 50-percent wall thickness reduction compared to austenitic grades in tubes and pipes designed to withstand internal pressure. This level of reduction translates into significant weight savings and consequent significant cost savings.

“All items in our standard stock are designed for operating conditions of no less than 16 bar and 50 °C. Smaller dimensions are applicable for much higher operating pressures.”

Nytomt sees wide potential for the lean duplex piping products in pulp and paper applications. Metso’s Mäntynen confirms, “There is definitely a place for these products.”