Tank for very low temperature liquids

A tank for holding a cryogenic liquid, comprising:

• a pressure-resistant layer having an inner shell and an outer shell;
• and
• an airtight resin layer on an inner surface of the inner shell,
• wherein the inner shell is comprised of a fiber-reinforced resin composite which can withstand temperatures above a melting point of the airtight resin layer, and
• the outer shell is comprised of another fiber-reinforced resin composite which can be cured at a temperature below the melting point of the airtight resin layer, and
• wherein the tank has an opening at a portion of the tank and said tank further comprises:
• a joint section having a first end engaged with the opening and a second end protruding outwardly from the tank, the first end having a flange, a part of which is attached at a periphery of the opening between the inner shell and the outer shell of the pressure-resistant layer;
• and
• an additional airtight resin layer covering a portion of said airtight resin layer, said portion of said airtight resin layer being at an inner periphery of the opening and at an unattached part of the flange.