Posted to News on 28th Feb 2007, 11:42
Special torque multiplier for remotely operated vehicle
Norbar has developed an aluminium version of its torque multiplier tool for a remotely operated vehicle used to assemble the Langeled gas pipeline under the North Sea.
As an integral part of the first offshore gas field where all the production stations lie on the sea bed, the newly opened Langeled pipeline, bringing gas to the UK from the Norwegian Ormen Lange gas field in the North Sea, was a vast engineering challenge. The fasteners that secure the sections of pipe together had to be tightened to a precise torque setting using a calibrated instrument.
Remotely operated vehicles (ROVs) provide the only practical means of carrying out the required torquing operations. And one of the challenges was to find a tool capable of generating a high torque to the required degree of accuracy, but which was also capable of being carried by an ROV. The solution, developed by Norbar Torque Tools and its Norwegian distributor Verkty AS Industri, was a special version of the Norbar HT14 torque multiplier, manufactured from aluminium rather than steel.
Lightweight and durable
The bespoke design weighed-in comfortably below the required payload limit, but nobody was really sure whether the aluminium construction would prove sufficiently resilient for arduous duties in such a hostile environment. However, factory acceptance tests showed that the HT14 was actually far more durable than anticipated. The aluminium-bodied HT14 entered service in 2005 and played a key role in the construction of the 1200km pipeline.
The success of Verkty's customised Norbar torque multiplier has generated significant interest from the oil and gas industry. The companies are currently collaborating to develop a version with built-in torque transducers in the gearbox to give a real-time readout of the applied torque.
