Airports, which store large reserves of jet fuel in aboveground storage tanks (ASTs), are increasingly turning to Vapor phase Corrosion Inhibitors (VCIs), as a smart solution for protecting tank floors from corrosion, complementing or replacing traditional cathodic protection (CP) methods, according to the US-based Cortec.

ASTs at airports are subject to stringent regulations to ensure physical and environmental safety, including preventing corrosion of tank floors, which can lead to hazardous leaks if left unchecked. Measures to prevent corrosion can save time and money by reducing the need for repairs, says the company which manufactures environmentally friendly, VpCI and Migratory Corrosion Inhibitor (MCI) technologies.

Cathodic protection has been a common method for inhibiting corrosion by sending an electrical current through the tank pad which offsets the normal electrochemical reaction of a corrosion cell. However, uneven tank floors can create air pockets, preventing consistent contact with the treated sand pad and allowing corrosion to occur in those areas.

“While CP has long been a go-to for corrosion inhibition, the last two decades of tank protection have seen CorroLogic VCIs become a new industry standard that offers a smart solution for protecting storage tanks at airports and beyond,” says a spokesman for Cortec.

VCIs, such as Corrologic, work differently. Once placed under the tank floor, they diffuse throughout the void space, forming a protective molecular layer on all reachable metal surfaces. This vapour action affords protection independently or in conjunction with CP, with research suggesting a possible synergistic effect between the two methods, he says.

Unlike CP, VCIs do not require a power source and can be applied at any stage of a tank’s lifecycle, including during construction or after the tank is in service, minimising downtime and the cost of draining large volumes of fuel, the spokesman points out.

Positive results from two decades of field trials have led to the underlying VCI technology being included in industry standards: API Technical Report 655 and AMPP SP21474-2023, he adds.

“As with any industry that involves ASTs, the aviation sector needs solutions to corrosion that make sense practically and economically. CorroLogic measures up to that standard as a relatively non-invasive technology with vapour-phase action that complements the deficiencies of other protective strategies and continues working even when CP power is off,” the spokesman concludes.