Cathodic protection

CESCOR has an extensive and specific competence for the design of all cathodic protection applications. Luciano Lazzari, CESCOR’s president, is author with Professor Pietro Pedeferri of an acknowledged reference work Cathodic Protection.
CESCOR has personnel certified in accordance with the European Norm EN 15257.
Cathodic protection application, by galvanic anodes or impressed currents, include:

• Overland, onshore and subsea pipelines
• Offshore steel platforms
• Jetties, Piers and coastal facilities
• Above ground storage tanks
• Buried and tumulated tanks
• Well casing
• Water boxes
• Equipment
• Reinforced concrete structures
  
  

CESCOR provides underwater cathodic protection inspections, including proprietary and patented instrumentation to be installed on ROVs or handled by divers, including – probes, electronics, software – and EN 15257 certified personnel for the execution of inspections.

Applicable techniques include:

• Close-to-remote potential profile (proximity)
• Potential gradient profile (field gradient)
• Trailing wire.

These methods, properly combined, allow to assess the protection level of the structure and to detect coating faults.

Typical inspected structures are:

• Subsea pipelines – open sea and shore approaches
• Offshore platforms
• FPSO and SPM.
• Piers and marine terminals.

The services we provide include the issue of the Inspection Specifications and of the Inspection Report. Where deemed convenient, inspection results are interpreted using FEM modelling.

Modelling by Finite Element Method (FEM) and Boundary Element Method (BEM) is routinely used by CESCOR for Advanced Cathodic Protection Design.

Computer modelling is used to study current and potential distribution on complex structures, to optimize anode positioning in both galvanic anode and impressed current systems, in order to avoid under-protected areas, to anticipate possible risks of hydrogen embrittlement caused by local overprotection and to correctly interpret cathodic protection inspection results or monitoring system data.

Applications include offshore structures, ships, tank bottom, pipelines, equipment.

CESCOR performs Cathodic Protection inspection surveys of buried pipelines to verify that correct protection conditions exist all along the line and to detect any coating holidays. Inspections are performed by EN 15257 certified personnel.

Inspection techniques include:

• Close Interval Potential Survey (CIPS)
• Transverse Gradient Method (TGM)
• Direct Current Voltage Gradient (DCVG)
• Signal Attenuation Coating Survey (SACS)
• Alternating Current Voltage Gradient (ACVG).

Isolating joints verification, potential data logging, soil resistivity and other additional measurements are also carried out.

A very specific application of Cathodic Protection is the retrofitting of in-service offshore platforms, which strongly differentiates from the case of new structures because of the constraints represented by underwater installation.

CESCOR has executed numerous retrofit projects around he world experiencing different solutions, both with galvanic and anodes and with impressed current. Amongst impressed current systems, the most effective solutions are:

• De Nora LIDA® TSA™ anode (tensioned anode strings) 
• Remote Anode Sleds.

In all cases, the optimal design of the most convenient retrofit system is also based on FEM modeling or BEM modeling, in order to optimize the positioning of the anodes and of the permanent reference electrodes to be used for monitoring the protection conditions.