Cathodic Protection Systems
Cathodic protection is a common method used to protect immersed parts of steel surfaces from corrosion. Offshore structures such as Offshore Jackets ( Offshore wind and Oil Processing Facilities), FPSOs, Floating Steel Structures are are in continuous operation for long periods of time to be protected as a whole as well as individual components which are attached to the structure. The protection can be provided by the use of electronegative materials such as magnesium, zinc or aluminium (sacrificial-anode cathodic protection).
Eventus, with its top tier partners (member of NACE Industrial Corrosion Society) in manufacturing sacrificial anode cathodic protection systems, is able to provide top quality CPs as per international codes and standards. Our scope is not limited to supply but also, engineering during FEED Phase, site surveys, installation and periodic controls of CPs done by our competent team members.
Type of anodes are as follows:
Zinc alloy anodes have a nominal potential of -1.10 VDC with respect to copper copper sulfate reference.
It is a high efficient anode ranging from %90 to %95. Zinc galvanic anodes can be casted and fabricated
in wide variety of physical shapes and suitable for different methods of mounting. Zinc anodes with a
backfill is used in soils having low resistivity commonly less than 2000 ohm.cm. These anodes are also
commonly used as a galvanic anode for marine application on steel ship hulls and to mitigate induced AC
on coated pipelines.
As galvanic anodes, magnesium anodes are available in two alloys, high potential (-1.75 VDC w.r.t
Cu/CuSO4) and standard (-1.55 VDC w.r.t Cu/CuSO4) ones. The magnesium alloys have an efficiency of %50 at
Maximum which means that half of the metal alloy is consumed in self-corrosion during its life. They may be
produced in wide variety of shapes as ribbons or blocks and available packaged with special backfill for
maximum possible efficiency in underground use. These anodes are most useful in applications where the
soil resistivity is moderately high includes fresh water and most soils.
Aluminum are mainly used in seawater environments. Different alloys are specified in international
standards for different marine and offshore applications. The potential of aluminum anodes as galvanic
anode is between -1.10 VDC to -1.15 VDC w.r.t Cu/CuSO4 depends on alloy composition and efficiency
between %85 and %95.
EN 12496:2013 – Galvanic Anodes for Cathodic Protection in Sea Water and Saline Mud
TS 9234 – Cathodic Protection – Galvanic Anodes