US Patent 10513896 Method of installing an unbonded flexible pipe

The present invention relates to a method of installing an unbonded flexible pipe with a bore for transportation of fluid wherein the unbonded flexible pipe comprises an outer sheath, an inner sealing sheath inside the outer polymer sheath, an annulus between said outer sheath and said inner sealing sheath and at least one metallic armor layer comprising iron located in said annulus, wherein the method comprises filling at least a part of the annulus with a corrosion promoting liquid before or after installing the unbonded flexible pipe between a first installation and a second installation.