System for storing and transporting a cryogenic fluid on a ship

An installation for storing and transporting a cryogenic fluid on a ship (1), the installation comprising:

• a sealed and thermally insulating tank (2) intended for the storage of the cryogenic fluid in a state of diphasic liquid-vapor equilibrium, the tank (2) having a ceiling wall comprising, in the direction of a thickness of the wall from the outside to the inside of the tank (2), a primary thermally insulating barrier (11) and a primary sealing membrane (10) intended to be in contact with the cryogenic fluid;
• a sealed line (14) penetrating through the ceiling wall of the tank (2) so as to define a passage for discharging the vapor phase of the cryogenic fluid from the inside to the outside of the tank (2), the line (14) comprising a bottom portion (15) of which a first end is situated inside the ceiling wall of the tank (2) and a second end is situated outside the ceiling wall of the tank (2) in a thicknesswise direction of the ceiling wall, and a top portion (16) fixed to the second end of the bottom portion (15);
• wherein the bottom portion (15), in contact with said cryogenic fluid, is composed of an alloy while the upper portion (16) comprises a stainless steel, said alloy of the bottom portion (15) having a lower thermal expansion coefficient than said stainless steel, and
• wherein the primary sealing membrane (10) is gas-tightly fixed to the bottom portion (15) of the line (14) around the line (14).