ISO/NP 26674

Cathodic protection for external surfaces of steel offshore floating structures

Scope

1 Scope
This document defines the requirements and giver recommendations for the external cathodic protection of submerged metallic surfaces of steel offshore floating structures which are static during their usual operating conditions.

This document addresses:
— design and implementation of cathodic protection systems for new floating steel structures and their appurtenances;
— cathodic protection by either galvanic anodes or by impressed current, or by a combination of both [hybrid systems];
— cathodic protection of appurtenances to floating structures including their mooring or station keeping provisions and any interfacing connections to other structures, offshore or onshore;
— cathodic protection in sea water or brackish waters and saline sediments;
—cathodic protection of structures fabricated principally from bare or coated carbon manganese steels;
— the control of any galvanic corrosion due to coupling between carbon manganese steel and more noble materials, such as corrosion resistant alloys (CRAs) including various grades of stainless steels and various copper nickel alloys etc;
— the control or mitigate hydrogen embrittlement or hydrogen induced cracking of possibly sensitive materials including high yield steel alloys, stainless steels and various copper nickel alloys etc;
— cathodic protection of any sea chests and water intakes up to the first valve;
— inspection, performance assessment and monitoring of cathodic protection systems installed on existing structures;
— assessment of residual life of existing cathodic protection systems;
— design and implementation of retrofit cathodic protection systems for improvement of the protection level or for life extension of the protection;