Leak-free under extreme conditions: Titelstory in the 6+7/2022 Issue of the Austrian Trade Magazine 'Betriebstechnik'
2 Ausgabe 6/7–2022 COVER 24° tube connectors with cutting ring are ge- nerally very durable and are regarded as the universal stan- dard for connecting metric tu- bes with outside diameters bet- ween 4 and 42 mm in hydraulic systems, reliably and without leaks. “For the application with the extreme conditions at the Lim- mern pumped storage plant, however, it would have been better to use a different joining solution – tube forming – from the outset, ” explains Uwe Bröl- los. He is the Key Account Ma- nager at Fluidtec AG in Kreuz- lingen, the authorised STAUFF partner for Switzerland. When leaks were discovered in 2019, only a few years after commissioning of the pumped storage plant, he was consulted as an expert for hydraulic line systems. The damage analyses showed that cracks had formed in some of the cutting ring tube connections, caused by the per- manent vibrations at the power plant. Uwe Bröllos recommended successively replacing the cut- ting ring connections with the STAUFF Form Evo forming system that was specially deve- loped for high-pressure appli- cations and strong vibrations. Forming: the “elite division” among tube connections The principle: The STAUFF Form machine is used to resha- pe the tube end so that a positi- ve connection is created during installation with a conventional fitting body and a union nut. STAUFF formed connections at Swiss pumped storage plant Leak-free under extreme conditions The hydraulic lines at the pumped storage plant Linth-Limmern in the Swiss Alps carry approx. 18,000 litres of oil. This requires absolute leak protection, because the connection systems for the lines are subject to strong vibrations. Unwilling to compromise in the future, the owners are having the origi- nally used cutting ring fittings successively replaced with the STAUFF Form Evo system. Foto: Axpo Power AG