Calibration and Pressure Relief of Hydraulic Wrenches and How to Solve the Stuck Problem
(Last Updated On: December 9, 2021)
In the process of using hydraulic torque wrenches, users often encounter three problems: how to calibrate the hydraulic wrench, how to relieve the pressure of the hydraulic wrench, and how to solve the problem of stuck of the hydraulic wrench.
TorcStark will introduce the solutions to these three common problems in detail for you.
How to calibrate a hydraulic torque wrench?
1. Place the hydraulic wrench and torque sensor on the torque verification workbench. Use the connecting shaft and the adapter to connect the three. During the connection process, attention must be paid to make the worktable firm and stable, and to keep the torque sensor and the hydraulic wrench torque axis level and strictly coaxial. 2. After adjusting the mutual position, fix the support arm end of the hydraulic wrench and the work surface firmly to ensure that the two do not move in mutual position during the process of applying force to the hydraulic wrench. 3. According to the rated torque value of the hydraulic wrench, the range of the calibration torque sensor should be selected correctly, and the zero position of the calibration device and the pressure gauge of the hydraulic wrench should be adjusted separately before installation. 4. Install the hydraulic wrench on the calibration device correctly, and then apply it to the rated torque value step by step according to the selected verification point, read out and record the torque value of each point, this procedure is carried out at least three times. 5. After each applied to the rated torque value, remove the load, check the calibration device and the hydraulic torque wrench indicator return to zero, and readjust the zero position.
Preparations to be done before hydraulic wrench calibration
Before calibration, adjust the zero position of the indicator of the calibration device and the torque value of the hydraulic wrench (corresponding pressure value on the pump station).
According to the size of the square shaft (socket) driven by the hydraulic wrench, select the adapter used to connect with it.
Check carefully whether the quick connectors of the oil pipes of the manual high-pressure pump are connected reliably and whether there is oil in the pump.
Connect the standard torque sensor, the workbench machine conversion joint and the hydraulic torque wrench, and fix them on the same axis.
After confirming the calibration direction of the hydraulic wrench, find the reaction fulcrum, which must be safe, reliable and stable. Then start to load and calibrate it according to the verification procedure.
Hydraulic wrench calibration cycle
There is a certain connection between the calibration cycle of hydraulic wrenches and the frequency of use. TorcStark recommends: Generally, tighten/remove bolts 5000 times or after one year of use, the hydraulic wrench can be calibrated once.
How to solve the stuck problem of hydraulic torque wrench
Before the hydraulic wrench is stuck, check the pressure on the hydraulic electric pump, and then increase the pressure of the electric pump station above the previous pressure. For example, the working pressure was 30Mpa before, so adjust the pressure of the pump station to 35Mpa. Keep pressing the high-pressure oil filling button without releasing it, and at the same time, pull the release trigger downward by hand, and the hydraulic wrench can be removed from the nut smoothly at this time.
If the hydraulic pump is at the maximum pressure of 70Mpa before it is stuck, then the pressure should not be adjusted, but still be maintained at the pressure of 70Mpa, and then pull the release trigger downward by hand.
Note: When you push the release trigger, you must push it with your hands. Never use tools such as a sledgehammer to hammer it.
Maintenance of hydraulic wrench
After the hydraulic wrench has been used for a long time, regular maintenance should be carried out on it. For example, the hydraulic oil needs to be replaced every 500 hours of work.
After each use, wipe clean the hydraulic wrench, the exterior of the pump station, and the oil pipe joints.
If it is not used for a long period of time, it is best to regularly pressurize the hydraulic wrench and pump station to prevent the seal from aging.
If it is not used for a long time, place the hydraulic wrench in a dry and sealed environment, which can effectively extend the service life of the hydraulic wrench.
How to relieve pressure of hydraulic torque wrench?
If the hydraulic wrench cannot release the pressure, it is mainly because the hydraulic wrench is stuck and cannot release the pressure. Some users may hit with a sledgehammer when encountering this kind of situation, which will not only damage the wrench, but also seriously affect the safety of the on-site operators.
In fact, there is a small inconspicuous part on the driving hydraulic wrench, namely the release trigger. I believe many people will not notice that the release trigger is located on each side of the hydraulic wrench. Its main function is: when the hydraulic wrench is stuck and cannot be removed, it can be easily removed by pushing the trigger.
Pull the release trigger to solve the problem that the hydraulic wrench cannot release pressure. The specific methods are as follows:
In such situations, just check the pressure of the hydraulic pump before the hydraulic wrench is stuck, and then increase the pressure of the pump station above the previous pressure. Then, keep pressing the button for high-pressure oil filling without releasing it, and at the same time, pull the release trigger downward by hand. At this time, the hydraulic wrench can be removed from the nut smoothly.
The above is about the calibration method of hydraulic torque wrench and pressure relief. If you have encountered other questions about hydraulic wrenches, or have experience in operating hydraulic wrenches, please leave a message in the comment area.