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News
Technology Transfer Improves Indicator Bolt
RotaBolt has developed the next generation of Indicator Bolt through the application of advanced bolting technology, increasing the extension monitoring performance of the existing fastener by dramatically improving correlation.
The standard Indicating rod bolt uses direct length measurement to gauge the delivery of load. The new version gives a much more accurate measurement of bolt extension to guarantee the uniform delivery and maintenance of load. RotaBolt has applied technology to produce bolts which are individually load test calibrated and fitted with a special indicator to measure extension. Every bolt even has its own certificate of extension measurement.
These improved bolts are a generational step forward for direct length measurement, commented Rod Corbett, managing director of RotaBolt, as a centre of bolting excellence, we have been able to apply our expertise to dramatically improve the performance of the existing indicator bolts.
The new fasteners were developed as part of a project where standard direct length measurement fasteners had been specified and designed-in, but were failing to perform to expectations. RotaBolt was called in and conducted an extensive programme of research and development.
Bolted joint specifications were reviewed, including theoretical calculations and tightening procedures, the assurance of the original design of the indicating rod was improved, and technology was then applied to increase performance and improve correlation. RotaBolt also worked closely in on-site training and testing, to successfully deliver the desired reliability for the client.
BreakBolt Launched
The BreakBolt is a unique safety fastener that is designed to deliberately shear at a predetermined tension level. The new bolts have been supplied to Vetco for use on specific offshore well head applications where a breakaway potential was required as a primary safety feature in the design of the riser system.
The BreakBolt is engineered to shear at a pre-set ultimate tensile load and has a specially machined waist, which reduces the tensile stress area, allowing the bolt to shear once it has reached the required tolerance. The bolts are tested to destruction at an independent test house and are certificated to their desired break load.
Designing a RotaBolt that would perform a controlled break under set conditions seemed a relatively straightforward task to begin with, commented Rod Corbett, managing director of RotaBolt, but it has been a major learning curve and has taken a great deal of research and development to perfect the procedure.
Rotabolts are Standard Fit on Terex Comedil Cranes
Over the last twelve months, Rotabolts have been fitted to over 50 cranes produced by Terex Comedil and are now standard fit on all HD23 22.6 and 26.6 crane towers. The technology contained within the unique Rotabolt design has provided Comedil with bolted joint reliability and assurance, essential in crane assembly and operation.
Pierluigi Tomasi, head of the technical department at Comedil commented, Fitting Rotabolts to our tower cranes and the undercarriages on our HD23 has given us a reliability that we couldnt achieve with tensioning tools and applied torque. Rod Corbett, managing director of Rotabolt added, Being able to guarantee the integrity and safety of bolted joints in critical locations is vital this is exactly what Rotabolts achieve. We are delighted that Terex Comedil are now reaping the rewards of assured reliability through the application of our technology, particularly in an area where safety and performance are of paramount importance.
The Vision A World First
Rotabolt has launched the worlds first safety bolt that constantly monitors tension across a bolted joint and gives a clear visual indication - visible from up to 25 metres away - as soon as any tension is being lost.
The new bolts operate on the same internal air-gap technology as the original Rotabolt but have a specially developed visual indicator which appears as an unbroken yellow line across the head of the bolt. As soon as any tension is lost across the bolt, the indicator instantly rotates by ninety degrees to show a distinct right angle break in the yellow line.
Sparrows Offshore have installed the Rotabolt Vision on one of the cranes on the Marathon Oil U.K. Brae Bravo Platform in the North Sea. The Vision bolts have performed very well - we have had no problems, commented Sparrows Offshore Project Engineer, Stephen Gowans, Within one hour we can carry out an eyeball check of all the bolts on the A frame of the crane. Previously, with a standard bolt, this is an operation that would have taken us all day.
