Patent ID: 7347225

Claim:
Multi-structure pipe of great flexibility ( 1 , 10 or 20 ) intended to transport a fluid, including an assembly of at least two structures concentric to the axis of the pipe and means to contain the transported fluid, wherein said assembly of structures includes a first internal tubular structure ( 3 , 12 or 22 ) having a set of substantially circumferential low pitch helical slits ( 5 ) bordering hoop resistant bands, each said slit extending on an arc of more than 180 degrees and less than 360 degrees in order to define a continuous opposite high pitch first tension load band ( 7 , 11 or 21 ), and at least a second structure ( 13 - 15 or 23 ) having at least one other tension load band ( 6 , 13 or 23 ) with a helix of same direction and pitch as said first tension load band ( 7 , 11 or 21 ), and said other tension load bands ( 7 - 6 , 11 - 13 or 21 - 23 ) of said structures are maintained to a fix distance from said first tension load band by support on the outside of said first internal tubular structure ( 3 , 12 or 22 ) to provide the capacity in tension of the pipe.