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Corrosive influence - The Dangers of Galvanic Corrosion

Peter Barter
Peter Barter on Engineering · Apr 22, 2020

Prevention is always better than a cure. Avoiding issues in the first place, rather than attending to them once they’ve occurred, is plain common sense. So why do so many industrial facilities install piping networks where gaskets and flanges are made from different metals, opening their doors to one of industry’s most unwelcome (and costly) guests – galvanic corrosion?

Corrosion isn’t just a technical, operative or maintenance issue – it’s a business-critical challenge.

The cost of corrosion

The degradation of metals within industry environments is dangerous (leading to fugitive emissions and accidents), inefficient (with the capacity to halt production) and often very, very costly, in terms of both maintenance and facility downtime.

In fact, a study by NACE International, the worldwide authority on corrosion, revealed that the global cost of the issue to industry is a staggering USD 2.5 trillion… or, in other words, 3.4% of global GDP at the time of research.

That is a ridiculous amount of money leaking out of the pockets of businesses across the globe. Money that, now more than ever, we simply cannot afford to waste.

Galvanic corrosion is arguably one of industry’s most pressing problems, but what is it, and how can we take the right preventative medicine?

Dangerous reaction

Galvanic corrosion is also known as dissimilar metal corrosion, which gives a fairly obvious clue as to why this electrochemical reaction takes place. When two dissimilar metals, such as steel and graphite, are coupled and exposed to a corrosive electrolyte (such as moisture) they corrode.

One of the metals becomes the anode in the reaction and corrodes faster than it would as a standalone material. The other (the more noble, with less chemical reactivity – for example silver or platinum) becomes the cathode and corrodes slower than it would on its own. Gaskets containing graphite are a particular area of concern, as graphite is the most noble metal there is. This is important as the greater the difference in nobility between the metals, the greater the rate of galvanic corrosion.

This degradation, with one of the materials undergoing a ‘supercharged’ process, undermines the integrity of the seal (or wider industrial infrastructure) and increases the likelihood of failure.

This is of particular concern in industrial segments such as hydrocarbon facilities, where leaks and failure can have catastrophic consequences, and maritime, with seawater acting as an all too effective electrolyte.

So, that’s the problem.

But what about prevention?

One of a kind

The solution is, frankly, right in front of our faces.

If dissimilar metals, such as those used in spiral wound gaskets, lead to dissimilar metal corrosion… then, well, don’t use dissimilar metals.

A solution such as Pipeotech’s DeltaV-Seal is the answer. The one-piece, CNC manufactured DeltaV-Seal is made from the same metal as the flanges it mates with. This means there is no electrochemical reaction, no anode and cathode, and no galvanic corrosion. And of course, no leaks.

The DeltaV-Seal is a ‘fit and forget’ solution. It has three unique sealing rings that deform on installation, filling any irregularities and creating the perfect seal, with no need for retightening or maintenance. No fire or blow out risk means no safety concerns and, with the problem of galvanic corrosion neatly sidestepped, no deterioration over the long-term, no matter how demanding the environment.

Make no mistake, galvanic corrosion should not be underestimated – but it can be avoided. And we can think of (at least) 2.5 trillion reasons why that is a good idea.

Give us a call, or drop the team a mail, to find out how we can help you prevent the problem of corrosion on your piping infrastructure… once and for all.


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