Cathodic protection (CP) is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. A simple method of protection connects the metal to be protected to a more easily corroded "sacrificial metal" to act as the anode. The sacrificial metal then corrodes instead of the protected metal. For structures such as long pipelines, where passive galvanic cathodic protection is not adequate, an external DC electrical power source is used to provide sufficient current.
Cathodic protection systems protect a wide range of metallic structures in various environments. Common applications are: steel water or fuel pipelines and steel storage tanks such as home water heaters; steel pier piles; ship and boat hulls; offshore oil platforms and onshore oil well casings; offshore wind farm foundations and metal reinforcement bars in concrete buildings and structures. Another common application is in galvanized steel, in which a sacrificial coating of zinc on steel parts protects them from rust. Cathodic protection can, in some cases, prevent stress corrosion cracking.
External Corrosion Direct Assessment (ECDA) refers to a structured process done in four phases. ECDA improves safety of pipelines through assessing and reducing the impact of external corrosion on pipeline integrity. This process prevents corrosion defects proactively from growing to a size that may ultimately hampers the field equipment structural integrity by:
• Locating and addressing corrosion activity
• Fixing corrosion defects by means of coating and cathodic protection.
• Removing the causes of corrosion
ECDA cannot be successfully assessed on all pipelines. Therefore, other assessment methods precautions should be taken when selecting ECDA techniques.
ECDA is a continuous process to improve pipeline safety and monitor external corrosion. Through using ECDAs, pipeline operators or owners can identify and address locations where corrosion has occurred or has the potential to occur. Since buried pipelines are out of sight, it is a key concern for monitoring the integrity of this pipeline to many manufacturers and process engineers. So a comprehensive system needs to develop to the continuous evaluation of the buried structure’s condition. This system is known as ECDA.
MCPL offers the followng Cathodic Protection services:
• Consultancy Services
• Structure Condition Assessment
• Repair and Rehabilitation Studies
• Water and Soil Corrosivity Studies
• Concrete Testing and Analysis
• Failure Investigations
• CIPS and DCVG Surveys.
• Cathodic Protection Design
• Cathodic Protection Audits
• Cathodic Protection System Monitoring
• Cathodic Protection System Maintenance
• Cathodic Protection Installation Supervision
• Cathodic Prevention for New Structures.
• Durability Monitoring Systems
• Corrosion Rate Monitoring
• System Selection and Specification