LNG tank system sets the standard
JAPAN's NKK's Tsu Works expects to complete the fitting of a Technigaz Mark III membrane tank system into a liquified natural gas (LNG) carrier by July.
The 18,800 cubic-metre carrier is being built for Asia LNG Transport of Malaysia to transport LNG from Malaysia to Saibu Gas Co, a gas company serving the northern part of Kyushu.
The project, believed to be a world first, will ensure that the tank is constructed to take into account both thermal contraction - caused by the cryogenic temperature of LNG (-162? Celsius) - and load-bearing insulation, a problem faced by many carriers.
The tank's cargo containment system - consisting of mastic, back plywood, glass-fibre reinforced polyurethane foam, bridge pad, face plywood and corrugated membrane - is being built inside the vessel's hold.
This new-generation LNG carrier incorporating the Technigaz Mark III system has advantages such as a high volume efficiency and compact design, good bridge visibility, easy maintenance thanks to a low, flat upper deck, excellent manoeuvrability and outstanding safety and strength ensured by the double-hull structure.
This and other features have been achieved through the adoption of original NKK technologies based on membrane-type LNG tank technology introduced from France's Societe Nouvelle Technigaz in 1971.
The company also organised and trained a welding team of 40 specialists to undertake the welding of the stress-free, corrugated membrane by advanced TIG automatic welding techniques.
To enhance safety, the vessel employs a full double-hull structure supporting all the cargo tank surfaces.