GAS DOME STRUCTURE FOR A SEALED, THERMALLY INSULATED VESSEL

The invention concerns a gas dome structure (1) for a sealed and thermally insulating tank arranged inside a double hull defined by an inner hull (5) and an outer hull (4); the gas dome structure (1) comprising: - an outer drum (20) capable of passing through two openings (18, 19) provided respectively in the outer hull (4) and in the inner hull (5); - an inner drum (23) that extends inside the outer drum (20), is secured to said outer drum (20) and is intended to be sealingly connected to the sealing membrane (9); - an intermediate insulating gap (24) arranged between the inner drum (23) and the outer drum (20); - le outer drum (20) comprising first and second collars (21, 22) that protrude radially outwards from the outer drum (20) and that are respectively suitable for being welded to the outer hull (4), around the opening (18) provided in the outer hull (4), and to the inner hull (5), around the opening (19) provided in the inner hull (5). Figure to be published: 4