Our thanks to Elma/Tovatech for allowing us to reprint the following article.
By Rachel Kohn, Ph.D., Tovatech
You’ve made an investment in an ultrasonic cleaning system because you know how efficiently ultrasonic cavitation removes contaminants from most any wettable surface. Here we present some tips on protecting your investment in the equipment, specifically the cleaning solution tank. We’ll cover the consequences of improper operating procedures (not that you would do that, of
course) and how to spot signs of potential problems.
Ultrasonic Cleaning Tank Construction
Stainless steel is the preferred material of construction for
ultrasonic cleaning tanks. That’s because of its high
resistance to cavitation action and chemical attack by
ultrasonic cleaning solutions. That said, highly acidic
cleaning solution chemistry should only be used in acidresistant
containers that can be immersed in a water
solution to which a surfactant is added. Ultrasonic waves
pass through the acid resistant container to act on objects
being cleaned in the acidic solution.
Takeaway: Do not use aqueous cleaning media with pH
values in the acid range (pH <7) directly in the ultrasonic tank if fluoride, chloride or bromide ions are present or can
be released from parts being cleaned. These can quickly
destroy stainless steel by crevice corrosion within a very
short period of ultrasonic operation.
Ultrasonic Cleaning Tank Signals
Cavitation erosion and pinholes occur in any tank but
can be slowed or minimized through proper use, regular
tank cleaning and filtration of the cleaning solution.
Cavitation erosion is the normal wearing of the tank
surface during use. It can be accelerated by dirt particles
that settle on the tank bottom as they fall from parts being
cleaned and abrade the surface. Acting as...
* Click to download article in PDF format