Method for producing a carcass, a method of producing a flexible pipe and a flexible pipe

A flexible pipe for conveying a fluid, said pipe comprising a center axis along the length of the pipe and from the inside and out;

• a carcass,
• an internal pressure sheath and
• at least one armor layer,
• said carcass comprises at least one first metallic strip and a cover strip, said first metallic strip comprises a first fold facing towards said center axis and a second fold facing away from said center axis, said cover strip comprises an anchor width section and a cover width section, and wherein said first and said second fold of said first strip being interlocked with said anchor width section anchored in said interlocking and wherein said anchor width section comprises weakening lines in at least a part of said anchor width section of said cover strip, wherein said weakening lines are fully penetrating the material of said anchor width section.

A method of producing a carcass for a flexible pipe, the method comprising:

• providing at least one first metallic strip and shaping said first strip to have a profile with a first fold adapted to face towards said carcass axis and a second fold adapted to face away from said carcass axis,
• providing a cover metallic strip with a length and a width,
• inserting an anchor width section of said cover strip into said first fold,
• providing that a cover width section of said cover strip extends beyond said second fold and
• helically winding said first metallic strip and said cover strip, to provide that said first fold engages and interlocks with said second fold and that said cover width section covers a helical interstice between windings of the first metallic strip on the inner side of the carcass,
• wherein at least a part of said anchor width section of said cover strip is subjected to a pretreatment before insertion into said first fold,
• wherein said pretreatment comprising a weakening treatment of resistance against length extension and/or a length extension of the pretreated part of the anchor width section, and
• wherein the part of said anchor width section subjected to the pretreatment comprises a width section which during helically winding of the at least one first metallic strip and said cover strip is subjected to tensile strain.

A method of producing a carcass for a flexible pipe, the method comprising:

• providing at least one first metallic strip and shaping said first strip to have a profile with a first fold adapted to face towards said carcass axis and a second fold adapted to face away from said carcass axis,
• providing a cover metallic strip with a length and a width,
• inserting an anchor width section of said cover strip into said first fold,
• providing that a cover width section of said cover strip extends beyond said second fold, and
• helically winding said first metallic strip and said cover strip, to provide that said first fold engages and interlocks with said second fold and that said cover width section covers a helical interstice between windings of the first metallic strip on the inner side of the carcass,
• wherein at least a part of said anchor width section of said cover strip is subjected to a mechanical pretreatment before insertion into said first fold,
• wherein said pretreatment comprising a weakening treatment of resistance against length extension and/or a length extension of the pretreated part of the anchor width section.