Biggest girth weld test gets underway

New frontiers in full scale fatigue testing have just been redefined by TWI's Structural Assessment team. It has completed destructive trials on pipe specimens no less than 30 inches in diameter.

This input pipeline, which the girth welded laboratory samples represent, forms part of the world's longest subsea export pipeline network from Nyhamna on the west coast of Norway, via Sleipner in the North Sea, to Easington in the UK.

In recent years more than 1000 full scale pipe fatigue tests have been successfully conducted at Abington. But only in recent weeks, following the installation of even greater capacity testing equipment, have very large diameter pipe welds been tested.

Norsk Hydro Produksjon AS commissioned the work for the Ormen Lange gas export project. It is the development operator for both the Ormen Lange process facilities and the Langeled pipeline infrastructure.

The combination of great sea depths, a highly irregular seabed, strong underwater currents, sub-zero temperatures and challenging wind and wave conditions, have imposed considerable technical challenges on all engineering parties.

TWI continues to invest in facilities to support fatigue trials, to ensure that it operates the world's leading test laboratory for the benefit of its Industrial Members. The recent expansion of the fatigue laboratories has enabled TWI to continue offering the quickest turnaround times for fatigue qualification testing of welded joints.

For further details of TWI's fatigue activities, please contact our Structural Assessment Section at email: STR@twi.co.uk