Pulse tools generate pulses instead of continuous torque:
Pulse tools must be tested on a static transducer (standalone transducer connected to a torque measuring instrument or a test bench equipped with static transducers):
Some of these tools have a shut-off valve that stops the tool when the target torque is reached. In that case, a mechanical joint simulator is needed between the tool and the transducer:
For pulse tools, only a portion of the energy of the pulses generates torque into the joint:
To regulate the pulse tools, follow this procedure:
|1||Regulate the tool to a low torque|
|2||Tighten the joint|
|3||Measure the residual torque with a quality control torque wrench|
|4||Adjust the tool torque and repeat steps 2 and 3 until reaching the desired residual torque|
The real residual torque found in the joint after the tightening operation depends from the joint mass and stiffness, the adapters used, the bolt friction coefficient.
To have the same torque reading between the torque measured on the torque analyzer system (or test bench) and the residual torque value, a Torque Correction Factor must be specified in the torque analyzer system.