Hydraulic Wrench Calibration
Hydraulic wrenches are perhaps the most linear of all torque tools when it comes to calibration results. These tools operate on a pressure versus displacement principle and normally produce extremely consistent results.
As with all torque tools they are subject to wear and tear and should be periodically serviced and calibrated. If any leaks are detected in the normal course of operation with this type of tool they should be tagged out of service immediately until the leak can be identified and repaired.
Calibration is performed in a test rig with a suitable torque transducer and readings are taken over the entire operating range of the tool.
Calibration results are then tabled in a torque versus hydraulic pressure format to allow the operator to select his desired torque output according to the hydraulic pressure of the pump used to operate this tool.
In addition the gauge used on the hydraulic pump should be periodically calibrated to ensure it is giving a correct indication of the hydraulic pressure applied to the tool as any variation will affect the resulting torque output from the hydraulic wrench.