Upgrade the existing Sacrificial Cathodic Protection System to ICCP system for 18m diameter existing tank bottom plate

摘要

The corrosion of metallic structures buried in soils or in contact with soils has long been a serious engineering and economic problem. All over the world many of buried structures such as (storage tanks, pipelines and critical structures foundations) are suffering from soil corrosion problems which affect mainly the external surfaces of these structures. This paper emphasizes a model defining adequate CP technique including pre-design, such that Current Drain Test and design requirements for upgrading the existing SACP system of external tanks bottom plates to permanent ICCP system. The upgraded ICCP system is in accordance with SABIC standards & specification, international codes and standards. Existing SACP system was commissioned on 1991, such that Zinc anode sheet was installed underneath tank bottom plate above an asphalt foundation. Inadequate protection was noticed after 13 years operation. ICCP distributed anodes system around the tank is one of significant CP technique where can be used to protect existing aboveground storage tank bottom. The anodes are distributed around the tank and installed in vertical ground bed configuration and away from tank ring beam. Such systems can achieve uniform potentials along the tank bottom surfaces.