But how do you recognise when these evaporations occur in the mechanical seal?
Our applications engineer Philipp Arneth shows me at our test bench:
“By monitoring the mechanical seal with our ultrasonic technology, it is easy to see what condition the seal is in during operation.
If, for example, evaporation of pumping or sealing media occurs in the seal gap, this is reflected in the transmitted data,” Philipp explains to me.
You can see it clearly in the illustration: the lubricant – in this case water – changes from a liquid to a gaseous state. This leads to insufficient lubrication and solid contact in the gap. This operating condition alone already damages the seal, but it is also an effect that can be followed by many different damage processes. These effects can occur in processes where gases are dissolved in liquids (e.g. carbonic acid in beverages), in processes with high temperatures or a pressure difference in front of and behind the seal (e.g. with highly volatile substances in chemical processes).
On our test bench, the media temperature was influenced by varying the speed in order to demonstrate this effect.
When checking the results, Philipp is very satisfied: “Here you can see very clearly the evaporation in the seal and the seal condition outside the defined standard range.