Large fasteners tightened for wind

This is especially true of wind turbines and other large pieces of critical machinery. However, German company, ITH, has developed a tool that will tighten all the bolts in a cylindrical assembly together at the same time. The hydraulic system was on show at the ITH stand at the Hannover Fair in April, where it was being demonstrated simultaneously tightening a ring of alternate bolts. The biggest advantage of the device is the accurate joining and uniform torque applied on all the bolts. By ensuring much better concentricity and axial alignment in the joint, eccentric loads are reduced. These cause fatigue and ultimately damage the gear train as the bolts work themselves loose. This allows much smoother running of the part, resulting in it lasting much longer. And if the items being joined are pipe sections, machine bolt tightening greatly reduces the possibility of leaks. The larger the items being connected, the more important the bolted joint becomes. ITH makes bolt tensioning cylinders for thread sizes up to 510mm and is able to design different shapes of bolt tensioning cylinders depending on the space restrictions of an application. It can cope with multi stage bolt tensioning cylinders for radially confined spaces or single stage bolt tensioning cylinders for axially confined spaces. Over 80% of bolt tensioning cylinders are a bespoke design for specific circumstances.