PRODUCTION OF SPHERICAL TANK FOR LIQUEFIED NATURAL GAS TANK, ETC.

Japanese Patent JP3793592

B2

PURPOSE: To provide a production method of a large basically spherical liquefied natural gas tank, etc. with an aluminum plate. CONSTITUTION: In a first stage, flat plates 4, 5 are welded by welding equipment preferably having a brushing device of a welding groove and a cutter for removing reinforcement of weld. In a second stage, a welded flat plate assembly is cut to a prescribed shape so as to be a structural pattern of the spherical tank. In a third stage, the flat plate assembly is bent to the shape of part of a sphere. In a fourth stage, the end parts 6, 7 of the plate assembly is machined to a shape suitable for a next welding process by a milling cutter. In a fifth stage, two of the bent assemblies are joined each other by using an operation device 3 having a tilting support structure part.