DNV Awards AiP for New LNG Fuel Tank Insulation

Risk management and assurance experts DNV, have granted an Approval in Principle (AIP) to PASSER Marine for the development of a new LNG fuel tank insulation system.

The new concept is designed for prismatic ‘type B’ LNG tanks – which according to IMO rules require a partial secondary barrier – and includes a leakage detection system capable of safely managing and containing fuel leaks.

Svein Konradsen, COO of PASSER Marine AS said: “The system we have developed is cost-effective and production-friendly and the pandemic has been challenging for many companies and for the development of this particular design.
The required testing has been difficult to finalise due to testing interruptions and limited possibilities to travel, but finally we have been able to submit the necessary documentation which I am very pleased to say was accepted by DNV.”

As LNG fuelled vessels are increasingly being deployed for deep-sea shipping, fuel tank sizes need to increase from 300-1000 m3 fuel capacity to up to 10,000-20,000 m3 leaving less room for cargo. Hence the increased interest in alternative fuel tanks in the industry – known as ‘type B’ – which are prismatic in shape and more volume efficient than traditional cylindrical ‘type C’ tanks. Between 95 and 99% of LNG fuelled ships contain type C fuel tanks, but many newbuilds on order contain ‘type B’ specifications.

“There are several insulation concepts under development that provide an integrated secondary barrier and leakage detection system, but there are few proven systems available on the market,” said Monika Johannessen, DNV Maritime Head of Department, Gas Carrier Excellence Centre.

An AiP is widely recognized in the industry as an early phase verification level for new design concepts or for existing designs in new applications