ALL ABOUT BOLT TIGHTENING
Posted on: October 25, 2017
The bolted joints relax after tightening due to gasket creep and embedment. Elastic interactions occur when multiple bolts are bolted in a joint and loosen a joint. The method of applying force to joint members to tighten a bolt is called bolt tightening.
Bolt tightening machines
The various machines for the process of bolt tightening are:
- Electric torque wrench
- Electric torque wrench-angle version
- Pneumatic torque wrench
- Pneumatic torque wrench-angle version
Electric torque wrench:
An electric torque wrench is one of the widely used bolt tightening machine. It is a combination of intermediate transmission with a planetary transmission and an electric drive. The drive includes an electronic control circuit and an electric motor. The torque controller sets the device to the desired torque.
Electric torque wrench-angle version
An electric torque wrench- angle version has the same machine set up and working except the fact that it can be set at a particular angle to tighten any bolt or nut.
Pneumatic torque wrench
Electric, pneumatic torque wrench is a collaboration of a planetary transmission with an intermediate transmission and a drive generated by a pneumatic motor. This bolt tightening torque machine has a torque wrench that collaborates with the pressure control unit set up by the water trap, a manometer and an oil lubricator for the compressed air.
Pneumatic torque wrench – angular version
This torque machine has the same machine architecture and working like that of the pneumatic torque wrench. The advantages of using this machine are that the torque can be adjusted and it has a more occupational safety.
Bolt tightening methods
The various methods used for bolt tightening operation are:
- Torque control method
- Rotation angle method
- Torque gradient method
- Elongation measurement method
- Loading method
- Elastic method
Torque control method
In this method, bolt tightening is controlled by the torque value. Bolt tightening is controlled by the torque value. It is the most general method of bolt tightening as it’s very easy. However, dispersion band of axial tension is wide, and efficiency is not up to the mark.
Rotation angle method
The bolt tightening is controlled by the angle bolt is tightened up to a definite angle by snug torque.
Torque gradient method
In this method, the bolt is tightened from the proportional point till the yield point is not reached.
Elongation measurement method
In this method of bolt tightening, the bolt tightening is controlled by the elongation of the bolt.
Loading method
The tightening of the bolt is controlled by the load.
Heating method
The elongation of the bolt is achieved by heating and is controlled by the temperature.
In all these methods various devices are used which one can get from a local store or even from an online store. One who wants to use the device on an immediate basis, the offline shopping of the same ( from a local store) can be more helpful as in the online store one can have a device at a low rate, but immediate availability of the same is not possible.
Powermaster - Manufacturers of Tube Tools, Bolting Tools and Spring Balancers 
Leave a comment