Smart CCP – Detecting Minor Damages in the Coating of Cathodically Protected Buried Pipelines

Cathodic corrosion protection (CCP) is a technical system which is used to reliably protect underground steel pipes against external corrosion. For high pressure gas pipelines of public gas supply with an operating pressure > 4 bar, the installation of this protection method is even stipulated. Remote monitoring systems are used to check the effectiveness of CCP based on measurements. The generated data can also be used to assess the condition of cathodically protected pipes. The remote CCP monitoring technology used at present has been designed to collect tho measurement parameteres which are required to prove the effectiveness of CCP and send the information as raw data to the evaluation centre. This technology, however, is not suited for a permanent monitoring of cathodically protected pipelines. For a continuous monitoring, a new technology has to be applied which generates a constant stream of CCP measurement data at a high sampling rate which is processed and evaluated in situ, so that only relevant information will be transmitted to the evaluation centre. This technology, which is innovative in the field of CCP, is called online monitoring. The motivation to advance remote monitoring technology to an online monitoring is to detect possible external impacts which may be dangerous to pipelines early, and avoid catastrophes, such as the severe gas accident on 30 July 2004 near the town of Ath in Belgium. Online monitoring is capable of detecting dangerous external impacts, such as for instance from an excavator bucket, on buried pipes with cathodic protection, and promptly transmit a danger alarm.