AN Australian bolt tensioning system is winning friends locally and internationally by employing the power, precision and speed of hydraulics to replace slow, cumbersome and hazardous alternatives such as slogging wrenches.
HydraNuts from Technofast Industries Pty Ltd are being used by mine, quarry and energy resource operations on machinery such as crushers, dragline drum and drag pedestals, vibrating screens, heat exchangers, drive motors and other machinery.
Two of the most recent applications of the award-winning technology involved crushers being employed at the world's largest diamond producer, Argyle Diamonds in Western Australia and by Placer Dome's North Mara Gold Mine in Tanzania.
Instead of relying on traditional slogging wrenches or torque tools to fasten nuts with twisting forces of various degrees of accuracy, HydraNuts were used to apply hydraulic force axially and evenly without torsion.
This stretches the bolt with exactly the degree of force needed for fastening in different applications. Loosening the nuts is simply a matter of pressurising the HydraNuts, releasing their lock rings and then releasing their hydraulic tension.
Resource uses have also included the use of another member of the HydraNut family, Modular HydraJacs, on heat exchanger units, where it was used to evenly tension bolting on machinery flanges.
Members of the HydraNut family are also used to fasten drum bearing blocks to the pedestal of hoists and drums on draglines.
HydraNuts have also been used on a drum and dragline pedestal to quickly and accurately load pedestal bolts that had been previously traditionally slogged or hydraulically torque tightened.
During the previous tightening process, torsional forces could move the alignment of the drum, causing re-work. Because the HydraNut directly tensions the bolt, there are no torsional stresses applied and therefore no relative radial movement of the nut face to the adjoining face. This also prevents damage to the abutting faces and thread interfaces.
Installation of HydraNuts is simple. They are screwed into position on the bolt. A quick connect coupling is connected and pressure is applied by a hydraulic pump.
The hydraulic force applied (which equals the pressure multiplied by the hydraulic area within the nuts' hydraulic reservoir) delivers a known load and can therefore be precisely and repeatably applied.
The bolt is stretched and the lock ring is wound down to seat on the top face of the piston. The hydraulic pressure is released and the hose is disconnected. The HydraNut takes only minutes to tension any bolt size.
HydraNuts are also widely used internationally by industries such as energy and electricity generation, manufacturing, materials handling, offshore oil and gas, petrochemical, process engineering, science and laboratory testing, steel and other metals industries.
Technofast has achieved its global success with this technology by adapting it to specialised applications. For example, it is so effective that the high-temperature version has been commercialised by Technofast US partner Nova for the nuclear industry, where it speeds up the job of critical bolting procedures and reduces ionising radiation exposure times for workers.
This HiTemp HydraNut demonstrated its credentials when it won an internationally coveted global energy award at the Platts 2004 Global Energy Awards in New York, being selected from 200 finalists to take the Award for Commercial Technology of the Year ahead of some of the world's leading companies in their fields.
HydraNuts range in size from palm-sized models to a 616mm HydraSure nut used in steel rolling mills.
Among the highest force output HydraNuts are the 178mm models used by Westinghouse in the US. These each produce up to 5900t.