Some of our hydraulic plants and gears foam in such a strong way that the foam oozes out of the tank or gear. What is the reason for this?
Oils behave the same as other fluids: A clean product hardly tends to foam. However, for reasons of safety, an active ingredient, mostly based on silicone, is added to the oil during the production to prevent foaming. Nevertheless, foaming can occur under certain circumstances. Surface foam, which lies on the surface as a stable layer of up to 5 cm in height, is no cause for alarm. Only when the foam increases extremely or even swells out of all openings is it a cause for concern. There are several reasons why an oil foams:
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