ELECTRIC TIGHTENING EQUIPMENT BY NORBAR
There are now many electric tightening devices on the market, which claim to be precise when tightening to large torques in the order of 500-6,000 Nm or more. Based on our experience, we have found that the values reported when measuring instruments from other manufacturers often do not correspond to reality.
Norbar is aware of the complexity of precision tightening and, after more than 10 years of development, introduced a new EVOTORQUE 2 electric tightening tool model at the end of 2016, which meets the torque and angle tightening accuracy requirements regardless of the type of coupling. The device has a compact design, works on 230 V. The tightening information can be stored in electronic form or stored in the device memory and then used back. Another important advantage of this device is the possibility even after years to check the tightening of a particular joint and to find out possible deviation due to non-tightening, vibrations, selection of unsuitable material, relaxation of a screw joint, environment, or also overtightening of the joint in the range of 100 - 7,000 Nm.
| CALIBRATED RANGE OF HAND TOOLS PRODUCED | TOOL WEIGHT | MASS OF REACTION |
|---|---|---|
| 200- 1,000 Nm | 10.4 kg | 1.5 kg |
| 270- 1,350 Nm | 10.4 kg | 1.5 kg |
| 400- 2,000 Nm | 10.8 kg | 1.5 kg |
| 540- 2,700 Nm | 12.85 kg | 2.6 kg |
| 800- 4,000 Nm | 12.85 kg | 2.6 kg |
| 1 200- 6,000 Nm | 16.8 kg | 3.9 kg |
| 1 400- 7,000 Nm | 16.8 kg | 3.9 kg |
| Accuracy to angle | +2° |
| Torque accuracy | +3% |
| Vibrations | > 2.5 m/s2 |
| Memory | 3,000 pieces of torque, angle, date, time and sequence data |
The calibration sheet is a part of the delivery.
See the included information leaflet.
They also wrote about the EvoTorque2 device in the Wind Energy Network 11/2017 magazine, https://www.windenergynetwork.co.uk/:
DEFINITIVE TORQUE CONTROL AND TRACEABILITY
Tightening essentially entails applying a moderated rotary force on a threaded joint.
When the torque is below or above the manufacturer's tolerance (under-tightening or over-tightening), it can cause significant damage in the turbine structure. This under-tightening or over-tightening situation has one key technical consequence, i.e., possible vibration in the turbine, which poses a risk of fatal failure.
Norbar’s development focused on maximum accuracy and reliability when checking already tightened joints or when applying torque on already tightened screw joints. Because Norbar is aware of the risks related to the slow response of the control unit as well as the so-called maximum flow currents in these electric motors, where, due to the loss of control, this can result in up to 100% dragging.
SOLUTION
Tools that are able to tighten the joints exactly to the required torque, check the pre-tight joints and then upload this data, exist. EvoTorque2 by Norbar allows users to tighten connections precisely and reliably and creates a record to confirm this fact, providing complete traceability of tightening for user teams and archiving of this data for subsequent maintenance of machinery and for the need to prove towards customers.
EvoTorque2 is capable of unbelievable checks under severe conditions – if the joints have not been tightened, the tools will show the torque values to ±3% accuracy. If the torque is applied again to the joints that have already been tightened, the results will be within ±5% of the set value.
TESTING
In the re-tightening test, EvoTorque2 demonstrated a clear advantage by achieving total accumulated stretching of around 15-20% (depending on the joint hardness) of the set target torque for 18 consecutive start-ups on the pre-tightened joint. This successive tightening would most likely result in damage to these tools or joints when using ordinary electrical tools. This tool is necessary for final tightening if you require precision and recording of tightening data.
The power of most electrical tools decreases as the engine temperature increases during use, resulting in less accurate torque values. The accuracy of EvoTorque2 does not change as a result of engine temperatures or temperature differences in general, thus allowing joints to be tightened in a series with guaranteed credible results.
ON THE GRID
The supply of wind farms is mostly provided by small generators with long supply cables, which increases the quality of the power supply. As a result, most electrical tools will not work or their output torque will be uncertain.
EvoTorque2 is immune to voltage fluctuations thanks to engine control technology – the engine will continue to function correctly or will indicate if the voltage exceeds the tolerance.
NEW ADVANTAGES OF TRACEABILITY AND CONTROL
Any torque or angle measured by EvoTorque2 may be recorded with a note of the corresponding date and time. The device memory is capable of retaining up to 3,000 of these values. They can be downloaded to a PC either using a USB cable or wirelessly using Bluetooth Smart.
The tightening modes include “Torque”, “Torque and Angle” and “Audit”. The first two modes allow the user to solely select the moment or combination of the target torque and angle.
INDEPENDENT TESTS
In addition to the above, EvoTorque2 has achieved the OK/PAA/APPROVAL standard in independent tests and calibrations carried out on a number of Spanish wind grids. This makes it the only electric tightener permitted to be used in the final tightening on the wind power plant.
The tools also represent a third party approved noise level that does not exceed 70 dB (A) and the vibration level is 0,304 m/s2, which significantly reduces health and safety risks such as loss of hearing or white finger disease during use.
EVOTORQUE2 TOOL RANGE
EvoTorque2 is available in 110 V and 230 V versions and sealed for IP44. The range covers requirements from 100 Nm to 7,000 Nm.
FEATURES AND BENEFITS:
- Up to 12 user IDs and their results can be saved. This is an undisputed advantage where tools are used by several users, e.g., in shift operation.
- There is an option to set a work ID for specific tasks (torque or torque+angle), e.g., a base screw, etc. Up to 20 work IDs can be set to a work group and up to 5 work groups can be set.
- The tasks may be grouped under one title. This is useful for multi-step flange tightening. This makes it possible to not only check the connections of one tower, but all the towers of the wind power plant and between several power plants.
- Users can now select the target torque for “Snug Torque” and “Angle Target”, i.e., threshold torque + target angle and target torque. This will make it easier to check joints for cross-tightening.
- "Operation Direction" – designed to enable the user to release any joint that has tightened.
- "Turn Angle" – this function guarantees that the joint must rotate by a certain set angle during tightening. This avoids the situation when a series of joints are tightened several times.
- To accelerate tightening, a two-phase tightening process has been implemented.
- EvoTorque2 calculates the number of its use and it is therefore possible to see how many times the tools have been used since the last zeroing.
- The tool has 2 locking levels that limit the user’s access to the tool’s options.
- Level 1 allows selection of pre-set targets
- Level 2 allows the tool to only be used in the already selected setting.
- The tools have newly expanded capabilities in ASCII mode, so it is possible to create user software according to the requirements of third parties for collection of measured values.
