Membrane LNG tanks are constructed of a laminate of thin plate invar (Fe-Ni) and a heat-resistant (perlite) box. Invar is 0.5 mm to 3.0 mm thick -extremely thin compared to the ship structure, and requires highly skilled tungsten inert gas (TIG) welding. Although machine welding centered an relatively simple components has been developed in Europe, complex components continue to require highly skilled welders. TIG automatic welding has been developed for use on the raised edges of tank corners, a type of component requiring high-level welding skills. These welds are highIy confined, and the joint shape changes in a complex manner. Key technologies include seam tracking for the weld line, automatic setting of welding condltions, and miniaturization to within 7kg per unit. The apparatus that was developed is effective for automated, efficient high-level TIG welding, and the first Japanese example of such application in the fabrication of membrane LNG ships is currently being studied.
Automatic TIG welding for raised edges of tank corners on membrane LNG tanks
Automatisches WIG-Schweißen hochgeborstener Tankbehälter-Kanten von Membran-Flüssiggas-Tankschiffen
Technical Review - Mitsubishi Heavy Industries ; 38 , 2 ; 52-56
2001
5 Seiten, 7 Bilder, 1 Tabelle, 1 Quelle
Article (Journal)
English
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