Smart Bolting Tools for the Wind Power Industry
In today’s multi-megawatt wind towers, various types of bolting equipment are used to tighten the thousand or more bolted connections in each wind tower. The time when most of these bolts need to be tightened is during the site installation, and the bolting equipment used requires generators and lifting equipment in order to be operated.
By Marcel Birkhoff, General Manager, RAD Torque Systems BV, The Netherlands
The two conventional bolting methods used in the wind industry are torque tightening with hydraulic wrenches at 700 bar and bolt tensioning (stretching the bolt with hydraulic cylinders at up to 2,000 bar pressure). Both methods have their pros and cons but ultimately both systems apply a certain clamping load to the bolted joint. In general, most bolts in wind towers are torque-tightened with common size bolts such as M24, M36, M48, M56 and M64 requiring torque values from 2,000 up to 15,000NM.
