At critical bolted connections, regular maintenance is required. The bolt must be tightened at the same torque as all other bolts for maximal strength of the connection. The weakest link determines the strength of the complete connection. However, critical bolted connections can be liable to vibrations or temperature fluctuations, which can cause the bolt load to decrease and deviate from the other bolts. When the bolt load has decreased too much, the connection is not strong anymore leading to incidents, for example, the collapse of a bridge.
With the BoltSafe system users can monitor their bolted connections. The BoltSafe washers, available from AMS Instrumentation and Calibration , measure the bolt load and transfer the data by cable to the Power Data Interface-New Technology (PDI-NT). The PDI-NT is a connection box for interfacing the BoltSafe network. The box can be adjusted, so that it gives an alarm signal if the required bolt load becomes too low in a bolted connection. In this way, the possibility of a weak bolted connection can be prevented.
The users need to place a BoltSafe washer between the nut/bolt head and the flange surface, and measure with the PDI-NT the actual bolt load during the assembly. This way the correct residual bolt load bolted joint is ensured. After assembly, the actual bolt load can be monitored, so under/overload and expensive check ups can be avoided.
The BoltSafe washers have the following applications:
- Measure the load of different joints, and guard the tension
- Monitor and guard the bolt load of the anchor bolts
- Bolt calibration
- Bridge and tunnels
- Petrochemical plants
- Wind energy
- Hydro energy
- Bolting contractors
- Attraction parks
The BoltSafe washers have the following advantages:
- Required tension can be achieved exactly, and can be checked at all times
- Guard the condition of the application
- Save in maintenance costs in time and money (work faster, plug on the reader and read out the data)
- Monitoring of the application from a distance so that maintenance can be done