At the end of 2021, Freudenberg Sealing Technologies (FST) had a good reason to celebrate. After years of continuous, determined persuasion at Hitachi Energy (formerly ABB Power Grids), FST landed its big fish and secured 10 percent of the global market for gas-insulated high-voltage switching systems.
Energy production is not the only way to minimize stresses on the environment. Smart materials and sealing solutions used in distribution systems can make contributions as well.
For years, employees from various FST departments had tried to get a foothold initially at ABB Power Grids and later at the joint venture that it formed with Hitachi Energy in 2020. But competitors were firmly entrenched with the customer, and FST products had drawn no interest during the different rounds of bidding.
There was a turn for the better when a paradigm shifted for the entire “high-voltage world.” Sulfur hexafluoride (SF6) was – and in some cases still is – used in high-voltage stations. For example, it is used as a quenching gas to extinguish short circuits when electric arcs occur. They can take place in transformers during the step down of 110,000 volts from overhead lines to 10,000 to 30,000 volts for local distribution networks. The switches in the facilities are filled with a protective gas to prevent arcs from occurring, or extinguish them, if necessary.
“As a protective gas, SF6 offers a high degree of safety as an insulating medium because it is nonconductive. But the gas is 23,500 times as damaging to the environment as CO2, and, to make matters worse, it remains in the atmosphere for about 3,200 years,” said Artur Mähne, Global Segment Manager, Hydrogen Technologies. That’s why individual U.S. states, such as California, heavily restrict its use for environmental reasons. Alternative gases have been on the market for about eight years, but they cannot be used in existing systems without technical adjustments.
INTEREST AWAKENED
After FST provided Simmerrings® for a new switch and successfully completed the first tests, experts succeeded in bringing the Hitachi Energy development manager and his team to an early, virtual meeting. In late 2018, FST invited representatives of the customer to a webinar so it could present its products and material expertise. Seven Hitachi employees took part. “We succeeded in awakening their interest. In early 2019, Hitachi Energy invited FST representatives to visit its headquarters in Zürich to discuss chlorobutyl rubber, or CIIR, for short, for use with alternative quenching gases. An outstanding collaboration emerged between the customer and FST’s material development operations in Weinheim, the Lead Center in Oberwihl, the Zürich Service Center, and our corporate sibling, Klüber Lubrication,” said Sales Engineer Stefan Huser, who led the project.
Mähne was simultaneously pursuing the path through Hitachi’s global purchasing department. Although the engineers expressed great interest, the purchasing department initially remained unconvinced, and its commercial decision-making authority overruled technology interests – for the time being.
BLUE INSTEAD OF GRAY
FST’s next material development also struck a chord with engineers at the potential customer. “We brought a blue CIIR to the market as an alternative for the gray EPDM material, which had slight conductivity,” Mähne said. In contrast to gray or black materials, it contains no carbon. Rubber is normally a good insulator but contains soot in most cases which, in turn, is electrically conductive. The CIIR is based on a mineral silicic acid, which is not electrically conductive
Normally, a new development of this kind takes two to three years to prepare for the market. “Fortunately, we had already worked on a similar material for another customer and were able to carry many insights over to this application,” Huser said. “This allowed us to develop an appropriate material almost overnight and score points with Hitachi Energy.” FST had finally reached the stage where the technology and not the price was the priority. “We were able to position ourselves as a highly competent problem-solver.”
SIGNIFICANTLY LESS PERMEATION
The conversion from SF6 to a different gas – carbon dioxide – posed difficulties since this option did not have the same molecular structure. “Its smaller molecules made it significantly more difficult to seal the switch. As we know from bicycle tubes and balloons, small oxygen molecules can migrate through rubber. Our new CIIR, on the other hand, hardly allowed even the tiniest molecules to pass through,” said Mähne, spelling out the advantages of the new material. One excellent feature: The material is well-suited as a true all-around player that can be used with a climate friendly insulating gas for other static seals. Another positive side effect: The material can be retrofitted in most applications. So there is the possibility of replacing existing EPDM seals.
Like General Electric, Hitachi Energy is one of the pioneers that switched from SF6 to CO2. Many other manufacturers have now taken this step and are using the more environmentally-friendly gas.
The close cooperation with Klüber Lubrication, a Freudenberg company, proved to be a big help in putting the project on the right track. “The application in the switching system is actually dry. It is a lubricant-free medium, but the seal requires a reasonable amount of lubricant. Here a question came up: Which grease would come into consideration and how it would interact with the gas?” said Mähne. “FST’s testing expertise was another asset that we could use to our advantage.” Since the company has its own test rigs, the testing could be done on short notice. Even the customer’s concerns regarding the seal aging and lifespans were quickly allayed after simulations at Freudenberg Technology & Innovation.
Freudenberg Sealing Technologies
has secured 10 percent of the
global market for seals for gas-insulated
high-voltage switching stations.
CUSTOMER-SPECIFIC STORAGE
Besides expertise in products and problem-solving, FST had another trump card: the Service Center in Zürich. “We reserve a warehouse for Hitachi at our center in Zürich. That allowed us to go from a ‘make to order’ to a ‘make to stock’ process. Small quantities can be delivered quickly, affordably and without complications. Hitachi Energy requires special packaging and labeling, for example with a CIIR-sticker, to avoid confusion with a similar product. Extreme cleanliness is also very important for these products. “We set up a special clean room for Hitachi Energy. We use it to package the parts to prevent any contamination,” Huse said.
The success is impressive: FST has secured a 10 percent global market share for seals for gas-insulated, high-voltage switching stations.
Hitachi Energy
Hitachi Energy is a leading global technology company that is committed to a future that relies on sustainable energy. It serves customers in various sectors, including energy supply, industry and infrastructure, with innovative solutions and services along the entire value chain. Collaborating with its customers and partners, Hitachi Energy has done pioneering work in technology development. It is facilitating the digital change needed to speed the energy transition toward a carbon-neutral future. Headquartered in Zürich, Switzerland, Hitachi Energy employs about 38,000 people in 90 countries and generates a business volume of about $10 billion U.S.
[Source: Hitachi Energy]
https://www.hitachi-power-solutions.com/en/service/field/td/sf6/index.html
