Intrinsically safe ICCP systems: key considerations

CP systems protect critical infrastructure from corrosion, and their design can become much more complicated if the system is intended for use in environments where volatile materials are housed. This is due to the risk of excess voltages and currents sparking a major explosion.

Therefore, all systems designed for these areas must be intrinsically safe and compliant. This article explores the best practice for using CP systems in hazardous environments, such as those found in South Africa’s Sunrise Energy project.

Located in Saldanha Bay, South Africa, Sunrise Energy is Africa’s largest open-access liquefied petroleum gas (LPG) import terminal. By enabling the import of LPG in large quantities, it advances the province’s oil and gas sector by boosting regional energy security and downstream competition.

On large-scale LPG projects like this, it is vital that CP systems are used to protect structures against corrosion. Normally, after being installed, CP systems are left to operate manually and are monitored periodically, especially when they are used on structures that are underground or submerged in water. This is the case in the Sunrise Energy project, which houses up to 5500 metric tonnes of explosive LPG stored in underground bullets that are protected using impressed current cathodic protection (ICCP).

Safety first

Because of the hazardous nature of the operating environment, the ICCP system used must comply with IEC 60079 standards. In South Africa, these standards define the requirements for electrical equipment in explosive atmospheres, and all CP systems in the hazardous area must conform to this as a minimum requirement.

Electrical equipment must also be able to operate safely in these settings by limiting the amounts of electrical and thermal energy available as a potential ignition source — because a single spark from a power leak could create an ignition source for a massive explosion that could endanger lives. This is achieved by only allowing low voltages and currents to enter the hazardous area, and by preventing any significant energy storage from occurring.

Furthermore, because the storage bullets are kept underground and are difficult to access regularly for inspections, the system must have remote monitoring capabilities to ensure ongoing protection.

The benefits of remote monitoring

Remote monitoring can be used to check performance and system integrity. Remote monitoring of CP systems in this way offers several key benefits for customers. Firstly, as regulations continue to evolve, data accessibility and transparency are more important than ever, and cloud-based remote monitoring platforms provide businesses with a single, easy-to-access repository for all live and historical data.

Secondly, by automatically monitoring and recording data relating to asset performance and system status, all abnormal events — such as power outages or system failures — can be reported directly to all relevant personnel without delay. This enables site managers and engineers to act immediately, which leads to significant reductions in maintenance costs as well as avoiding any unnecessary downtime.

Thirdly, the ongoing maintenance costs are lower for enterprises that use remote monitoring technologies to monitor their CP systems. This is because they don’t need to physically inspect difficult-to-access systems, like underground LPG containers, or pay for engineers to conduct routine onsite inspections. Furthermore, the duration of any necessary onsite inspections is lessened because preliminary testing can be done remotely before the visit. This reduces the overall cost and minimises any disruption caused by the inspections.

The solution Omniflex provided for Sunrise Energy has several key benefits, including automatic regular testing, long-term cloud-based data logging, and alarm condition alerts via SMS and email. It was installed in field marshalling panels, with the HMI panel located in the control room allowing full system monitoring and testing.