On demand we can make inside leakage test on your unit, finding out, is there any cracked or hole plate in your heat exchanger.
For this test, the unit can be on-site, and assembled. After discharging fluids from the unit, we fill up one side by former gas (95% Nitrogen and 5% Hydrogen).
On the other side, circulating air through the unit, we measure H concentration by our ultra sensitive Hydrogen detector (sensitivity is 0.5ppm). If there is some beginning crakings or dot-corrosion, the smallest and fastest Hydrogen molecule will be the first which can pass through the hole.
The crakings or dot-corrosion can be find as initial stage when water molecules can not pass the hole or crack yet due to their big size.
With this method you can use preventive maintenance against crackings and dot-corrosion. In dairy and brewing industry, the traditional theory was that cross contamination prevented by booster pump in the regenetrative section of the PHE.
However, researches prooved that microorganisms may pass cracks from lower pressure side to higher pressure side due to osmotic force (reference: Raimund Kalinowski, Brauindustrie 08/2007)