Butterfly valve performance – 40 years and counting
The story of the 40-year-old Neles butterfly valve series began back in 1973 when the co-founder of Neles Oy, Antti Nelimarkka, asked his team to finalize a sketch he had drawn in his legendary notebook. The challenge had been to develop a butterfly valve that could withstand temperatures up to 600 °C (1,100 °F) and still maintain excellent tightness and durability characteristics.
The first of its kind
It was clear that only a metal-seated valve could work in such conditions. However, no such designs had existed before. After two years of development, the Neles R&D team came out with a Neldisc valve that immediately proved to be an exceptional success. The U-shaped metal seat and elliptic disc formed a unique triple offset valve design, which are used in many butterfly valve products today. At that time, however, this was a first. Furthermore, the first deliveries at the end of 1975 exceeded all expectations.
New applications discovered throughout the years
In 1982, based on the proven design, a low-temperature cryogenic, high-performance butterfly valve was developed to expand into liquefied natural gas applications. And from there, many other possibilities for this product were discovered. For instance, butterfly valves are excellent for control applications, as there is no seat friction in the control range and the valve’s rangeability is surprisingly high.
Further doors opened with the realization that butterfly valves close much faster than other valves, such as ball valves, offering excellent performance in ESD and other on-off applications.
Designs based on customers’ needs
Today’s Neldisc family members are numerous and available in all major end designs. Many options exist for demanding applications that require high-cycling resistance, steam jacketing, erosion resistance and much more. Thanks to the flexible basic design concept, the valve’s functionality can easily be extended to cover new applications.
Metso’s butterfly valve offering is currently the most comprehensive in the entire valve industry. And many new success cases have been created based on actually customer requests.
Next-generation design for next 40 years and beyond
Over the past 40 years, Metso has supplied more than 700,000 Neldisc valves throughout the world with numerous memorable Neldisc valve deliveries. One of the most important was in 2004 when Metso delivered an 80” Neldisc butterfly valve, the biggest Neldisc unit manufactured until then, to a gas plant in the Middle East. In 2013, a heavy 80” double-flanged valve was delivered together with over 280 other butterfly valves for a cracked gas application at the Sadara polyethylene plant in Saudi Arabia.
The development of Neldisc butterfly valves is still in full swing. The next-generation Neldisc design is already in the works, aiming to set the industry benchmark in the field of high-performance butterfly valves during 2016. With this facelift, Metso is honoring the 40th anniversary of the first-ever metal-seated butterfly valve – and is planning to ensure this valve’s success for at least the next 40 years.
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