Wireless galvanic cathodic protection comes to Australia

Australia’s first use of wireless remote monitoring and testing of galvanic cathodic protection installations.

With the widespread adoption of Industry 4.0 and Industrial Internet of Things (IIoT) technologies, the benefits of remote monitoring are more compelling than ever. Furthermore, businesses continue to face challenges around conducting site visits to inspect system performance because of the ongoing coronavirus pandemic. Unfortunately, problems like corrosion are not waiting for people to get back to site to control it. Here David Celine, managing director at cathodic protection specialist Omniflex, discusses the latest use of using remote monitoring technology to monitor and test a galvanic cathodic protection (CP) system in Australia and the benefits it brings.

Corrosion is a natural, electrochemical process where metals are gradually degraded and destroyed as part of an anodic oxidation process that compromises the metal structure. In galvanic CP applications, a steel structure is connected to a series of anodes made from a metal alloy with a more negative electrode potential than it, such as magnesium, aluminium or zinc. This guarantees that the metal structure is always the cathode of the electrochemical cell, and the metal alloy becomes a sacrificial anode that is consumed by corrosion, rather than damaging the structure.

Typically, galvanic CP installations are not regularly monitored, if at all, with many users wrongly assuming the simplicity of the systems will ensure their ongoing performance and asset protection. But in a world of increasing requirements for compliance, performance guarantees and reporting, strategic assets require more regular monitoring. In the absence of remote monitoring capabilities, this involves carrying out increasingly regular physical visits to sites by experts — something which is time-consuming and expensive at the best of times, even more so since the global pandemic started.

A classic problem
On a concrete bridge on the Gold Coast in Australia, galvanic CP protects the pre-stressed steel concrete pilesusing submerged aluminium anodes. The system faces the classic problem involving pre-stressed steel with cathodic protection - there is an ongoing risk of hydrogen embrittlement caused by over protection as salt levels change in the concrete and in the water.

If hydrogen embrittlement occurs, the steel will degrade and the structure will become unsafe, ultimately leading to its closure. Furthermore, operators cannot rely on manual inspections to counter this problem because, by the time you can visibly observe the signs of embrittlement, the damage is already done. With the risks being so high, installing remote monitoring technology was a no-brainer to ensure protection while also identifying any occurrences of over protection.

Australia’s first remotely monitored and tested galvanic CP
Omniflex recognised the need for remote monitoring for galvanic CP installations and developed the world’s first battery powered instrument for remotely monitoring and testing galvanic CP installations wirelessly via the web— The PowerView iGAL. The iGAL can not only monitor anode currents but also measure reference electrodes and coupon currents as well as perform instant off and depolarisation testing. The iGAL is designed to help asset managers monitor the corrosion of embedded metal structures while cutting down the need to physically visit the site to undertake time-consuming, costly and often hazardous surveys.

Having already proven itself in UK-based galvanic CP applications, the consultants managing the Gold Coastbridge’s CP system installed the iGAL onto the bridge to ensure its ongoing protection and monitor system performance. With the system now in place, the consultants can gather and monitor system performance 24/7, even when they were forced to work remotely because of the pandemic. The reality is that remote monitoring is no longer just the most cost-effective way of gathering system data, it is now the only way to do so in many cases.

www.omniflex.com

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