Liquid natural gas (LNG) at atmospheric pressures, remains as a liquid at -162°C. As the temperature increases, gas is evolved which is flammable and under certain mixtures with air is explosive when in the presence of an ignition source.
As designers have looked more at the risks posed by accidental release of Cryogenic Liquids onboard FLNG assets, it has become more apparent that the steel structures used for these facilities could be prone to brittle fracture. This could potentially lead to structural failure. If fire ensues soon after this cryogenic release then further escalation may occur, particularly if the passive fire protection does not function as expected.
The need for effective, tried and tested solutions to mitigate the risks posed by cryogenic liquid gas exposure was identified nearly 20 years ago. In the last 10 years, as the FLNG industry has accelerated, development has intensified for cryogenic spill protection (CSP) systems. Indeed construction of a leading FLNG asset was nearly stopped due to the lack of an effective solution. In response, the owner initiated studies into the most effective CSP materials to ensure progression of the project.
Since then, the industry has developed a better understanding of the risks posed by these LNG liquefaction assets and the consequences of not addressing these risks appropriately. Working closely with owners and design engineers to address these project specific risks and to develop robust solutions, has therefore become of paramount importance in developing this appropriate response.
This paper covers the initial requirements of protection against cryogenic spill. It considers the solutions developed to meet all the industry standards and describes those finally adopted by the first FLNGs under construction.
