Tank for storing gas

A tank comprising a multilayer structure, for the storage of compressed gas, comprising at least the following three successive layers, from the inside to the outside:

• at least one sealing layer consisting of a composition comprising on a majority basis at least one semi-crystalline thermoplastic polyamide, having a melting temperature (Tf), measured according to the standard ISO 11357-3:2013, less than or equal to 280° C.,
• at least one intermediate composite reinforcing layer consisting of a fibrous material in the form of continuous fibers impregnated with a composition comprising on a majority basis at least one semi-crystalline thermoplastic polyamide, having a glass transition temperature (Tg) measured according to the standard ISO 11357-3:2013, less than 100° C.,
• at least one outer composite reinforcing layer consisting of a fibrous material in the form of continuous fibers impregnated with a composition comprising on a majority basis at least one polyphthalamide having a glass transition temperature (Tg), measured according to the standard ISO standard 11357-3 2013, higher than 80° C.,
• the outermost sealing layer being welded to the innermost intermediate composite reinforcing layer, and
• the outermost intermediate composite reinforcing layer being welded to the innermost outer composite reinforcing layer.