| Using tensioning device |
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| Written by BRIFEN Australia | |||||||||||||||||||||||||
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The tensioning and detensioning of Brifen WRSB should be undertaken at the rigging screw and anchor locations. The procedure to check the tension across a rigging screw is as follows: Connect the POWERTEAM chains to the wire rope, so that one tension clamp is on one side of a rigging screw and the other is on the other side. The pull cylinder is connected by shackles in line to one of the tension clamps. Pressure is then applied to the pull cylinder by the hand pump and the resulting tension is shown on the pressure gauge. Pump the hand pump until the POWERTEAM chains are taut and will slightly loosen the rigging screw. This ensures that the POWERTEM system is now taking the load (tension) in the wire. ; "Temparature chart") Temparature chart Now increase the tension in the wire (on both sides of the POWERTEAM) by pumping the hand pump until the pressure gauge shows the required pressure reading (ie. tension) . It is essential that the rigging screw is also tightened simultaneously. When the gauge shows the required tension (pressure), turn the rigging screw another turn until the pressure gauge shows a slight drop in pressure. This indicates that the rigging screw has now taken over the tension in the wire rope and the wire has been tensioned to the required value. This procedure is now repeated at the other rigging screws and for the other ropes. The same procedure can be applied at the anchor locations, except that one clamp is connected to the wire on the anchor. SELECTING CORRECT TENSION USING POWERTEAM TENSIONING KITThe tension in the ropes varies with the ambient temperature. The Tensions increase when the temperature is cold and the steel contracts. Conversely, when it is hot the steel expands and the tensions decrease.As such, it is important to tension the fence according to the ambient temperature on the day, and the annual average local temperature! The Tensioning table (above), allows you to do this, as long as the ambient temperature at the time of tensioning is known. The following procedure should be followed. ; "Example") Example 1.Click on the state->2.From the list, pick your location (or the nearest one)->3.Determine Min & Max temperatures (see our example above). Or go to:www.bom.gov.au and follow the links. 2. Onsite, measure the temperature as you are tensioning. We recommend the use of a thermometer for this task. Do not place the thermometer on the road, on metallic surfaces or in the shade as misleading results will ensue. Also, do not cover the bulb with your hand. 3. You can work out the difference between AALT & the ambient temperature. Difference = Measured Temperature – AALT (see real life example and detailed explanation in Temperature chart - above) 4. Use this difference (in Temperature chart - above) to get the corresponding expected gauge reading.
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| Last Updated ( Thursday, 12 July 2007 ) | |||||||||||||||||||||||||
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