EuroWire September 2023

Products

Hydromechanical spring clamping nuts

A joint press release detailed how “the alignment and quick connection of the tower was successfully performed with- out any personnel below the suspended load. The C1 Wedge Connection features pre-installed fasteners, and only light- weight tools are needed to finalise the connection.” The technology is DNV certified, as C1 Connections demonstrated that the connection works, has tested fatigue and ultimate capacity, and can be built full scale for large wind farms. Nord-Lock Group met C1 Connections with a common goal to simplify bolting assemblies, protect workers and build more robust applications. Christophe Cuypers, Nord-Lock Group tensioning key account manager, said, “I am extremely pleased that Nord-Lock Group can support this innovation with the design and testing of custom Boltight hydraulic tensioners – used to accurately pre-tension the C1 Wedge Connection.” Nord-Lock Group www.nord-lock.com pressure. This means that as the spring pack is compressed with increasing oil pressure, the spring force increases. At set pressure, the corresponding nominal clamping force is achieved as the reaction force of the plate spring package. To release the pressure or tension piston requires a higher hydraulic pressure that is proportional to the release stroke, up to a maximum value. The setting pressure is therefore only required for the initial installation, for exact force adjustment. In the actual operating cycle, the cylinders are driven either without pressure or with release pressure. For spring-loaded cylinders, a mandrel or tie rod is screwed into the threaded hole of the tensioning piston and secured (on request, in one piece or with special thread). Operation requires a hydraulic unit equipped with a pressure gauge, a pressure relief valve, a switching solenoid valve and a pressure switching device. Jakob Antriebstechnik GmbH www.jakobantriebstechnik.de

stressed plate spring package. The hydraulics are only needed for the release stroke of the elements, when the tie rod or pressure pin is released. This system ensures a high level of operational safety, since the clamping force is always maintained at full height, regardless of oil pressure or leakage losses. In operation, the pressure or tension piston is alternately acted upon by the plate spring package or the hydraulic

The spring-loaded cylinders of the ZSF series from Jakob Antriebstechnik offer robust and reliable clamping elements. The systems can be used wherever displaceable or movable machine parts must be temporarily clamped or locked. Other applications can be found in jig construction and for workpiece or tool clamping. The spring-loaded systems interact mechanically-hydraulically. The clamping force is applied mechanically by a pre hydromechanical

ZSF spring-loaded cylinders

A sea change for offshore installations To harness the power of wind, inno- vations from smaller specialist partners can enable faster, safer turbine by C1 Connections BV, is a fastening technology that can deliver the high capacity needed for this new generation of wind turbines.

installations and service. Nord-Lock Group, C1 Connections BV and Heerema Marine Contractors have collaborated on a new breakthrough. As wind turbines get larger, and are located in increasingly harsh environ- ments or on floating platforms, con- ventional bolted L-flange connections, which are complex to design, install and maintain, are reaching their limits. The C1 Wedge Connection™, developed

Turbine towers can be aligned to the foundations without personnel. The C1 Wedge Connection features a remotely actuated quick connection for a fast and safe release from the crane hook, after which operators can enter safely, push in the fasteners and apply the final preload using handheld Boltight™ hydraulic tensioners.

While traditional L-flange connections are exposed to sea corrosion, the C1 Wedge Connection is designed so that the most critical parts stay dry, mitigating corrosion. During an offshore test with Heerema Marine Contractors, C1 Connections demonstrated that its solution enables a safe disconnection of the tower from a grillage on a barge.

Boltight hydraulic tensioners

EF 6/76

www.read-eurofasteners.com

September 2023