DNV GL published a revised version of Class Note 30.9, sloshing analysis of membrane LNG tanks.
Class Note 30.9 has since its first release in 2006 been a unique reference for sloshing assessment of membrane type LNG tanks. Like no other document it provides in-depth description and guidance on how to perform the assessment.
Items covered by the Class Note are sloshing fundamentals, assessment basis and principles, sloshing impact load assessment, sloshing load assessment for pump tower structures. It also covers structural resistance and strength assessment of load bearing insulation, strength assessment of the inner hull structure supporting the insulation and strength assessment of in tank pump tower and tower supports.
The original version of the Class Note was ahead of its time in many ways, and pointed the way for much of the development seen in sloshing assessment methodologies in the years following its release, mainly in the period from 2007 – 2010. Although still relevant in many respects, there was a need to revise the document to bring it in line with the current assessment practice followed by DNV GL and the main players in the industry.
The revised version of the document contains the following main changes:
The revised Class Note 30.9 entered into force from August 2014. Copies of the document can be downloaded from DNV Exchange .
Press Release, September 5, 2014; Image: DNV GL