On 8 November 2012, during normal operations, a powerful steam leak occurred at the Mongstad facility in Hordaland. No-one was seriously injured in the incident and the material damage was slight. However, the incident had a large potential for injury, with a risk of multiple fatalities.
A two-inch steam pipe ruptured abruptly, allowing large volumes of superheated steam and water to flow out rapidly, at an estimated rate of 16.9 kg/s. Had the leak occurred a few hours later, up to four people might have sustained life-threatening injuries or been killed.
The leak occurred due to heavy corrosion beneath the pipe insulation. In sections of the fracture zone on the steam-pipe, there remained a wall thickness of only some 0.5mm of the original thickness of 3.9mm.
The primary cause of this heavy corrosion on the outside of the pipe is thought to be wetting of the insulation over a long period as a result of corroded and damaged exterior metal sheathing, and periodic blowdowns in the steam-pipe having produced optimum temperatures for corrosion to take place. There may in addition have been leaks from a steam heating pipe.