Many times we have already spoken about cleaning of plate heat exchangers, related to revamping, cleaning and maintenance and fouling factor. The topic is wide and worth a more in depth analysis.

In case of plate heat exchangers that can be inspected, it’s clear that cleaning is easier, but relatively easy in fact. Let’s say that being made to be inspected, it is sufficient to dismantle and open the exchangers and wash them, using acids, cleansers and more or less aggressive fluids. And once they are cleaned, close them again.

But this is not enough. Because usually this intervention is also integrated with a dye penetrant testing, in order to ensure that plates are not broken, cracked or showing corrosion.

In fact, evident effects of corrosion can be eye catching, but there can be also micro crackings, maybe due to a bad maintenance, for example if the plates pack has been clamped too tight and plates have been crushed. This cannot be evident, and it can be checked out only using dye penetrants. A testing operation that is performed on the 100% of the plates.

Another operation that can be made, even if it’s not necessarily required, but sometimes it is, is to provide a substitution of gaskets.

Most of the times, the cleaning process involves the removal of gaskets, plates cleaning and re-mount of the gaskets, especially if these are clip-on gaskets, not glued. But there can be times when gaskets are worn out and so they must be replaced. In this case, the revamping involves also the substitution of the overall gaskets pack.

This is clearly a quite invasive operation, and also quite expensive that is worth to carry out on plate heat exchangers of a certain size. In case of very small plate heat exchangers, very often it cannot be worth the cost, and a complete substitution of the plates pack could be more cheap.

 

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