Key Points for Installation and Maintenance of Fastening Systems
- What are the requirements for bolt torque during the installation of the fastening system?
The bolt torque must be applied strictly in accordance with the design requirements. The torque values vary for bolts of different specifications and different application scenarios. Generally, for bolts used in ordinary railways, the torque is within a certain range. For example, the torque of an M24 bolt may be required to reach 300 - 400N·m to ensure that components such as elastic clips and fishplates are tightly connected to the rail and prevent loosening. On high-speed railways, the accuracy requirement for bolt torque is even higher, and the deviation range is controlled within a very small value to ensure the stability of the track structure.
- What are the precautions for installing elastic clips?
When installing elastic clips, it is necessary to ensure their accurate position, with both ends evenly pressing on the rail and closely fitting the rail without obvious gaps. The elastic clip should not be over-deformed during installation to avoid affecting its elasticity and clamping force. For different types of elastic clips, such as type I and type II elastic clips, the installation methods and requirements are slightly different, and the corresponding specifications must be strictly followed to ensure that the elastic clips can normally play the role of fixing the rail and reducing vibration.
- How to conduct a preliminary inspection after the installation of the fastening system?
The preliminary inspection includes visual inspection to check whether all components are installed in place, and whether the elastic clips, fishplates, etc. are deformed or damaged. Check whether the bolts are tightened, and a torque wrench can be used to randomly check whether the torque value meets the requirements. It is also necessary to check whether the gauge is within the standard range, which can be measured with a gauge ruler. If the gauge deviation exceeds the allowable range, the position of the components of the fastening system needs to be adjusted.
- What does the daily maintenance of the fastening system include?
Daily maintenance requires regular inspection of bolt torque to prevent bolts from loosening due to train vibration and other reasons. Generally, the torque of bolts at key parts is checked once a month. Check whether the elastic clips have fatigue fractures or plastic deformations, and replace them in time if necessary. Clean the surface debris of the fastening system to avoid debris affecting the contact and connection between components and keep the track clean. Check the wear of components such as fishplates and arrange for replacement when the wear is severe.
- What aspects need to be paid special attention to for the fastening system after severe weather?
After heavy rain, check whether the fastening system has rusted due to water immersion, especially in parts such as bolts and elastic clips, and carry out anti-rust treatment in time. After strong winds, check whether the connections of all components are loose, as strong winds may intensify train shaking and cause the fastening system to loosen. After extremely cold weather, pay attention to checking the low-temperature performance of components such as elastic clips to see if they become brittle due to low temperatures, affecting their fastening effect.