seal face fluid film thickness

[jet1749]

I am aware that a minimum film thickness for a product such as water would be 1 micron, but what about a maximum film thickness bearing in mind solids of between 50-80 micron present in the product.

 

[JJPellin]

The presence of solids should not affect the film thickness. In fact, I have often heard that the presence of some particles in the fluid is irrelevant, because a properly designed and operated mechanical seal makes an excellent filter. That is to say, if the film thickness is less than 1 micron, particles larger than that cannot get between the faces. Unfortunately, in the real world a seal is likely to see some upsets that would cause the faces to open up (vibration, product flashing, misalignment of stationary and rotating parts). If the faces open up, the larger solids can get in and then the faces can close back with the solids there. If one face is soft (carbon) the particles might imbed. If the faces are hard, the particles may be ground up, doing some face damage in the process. I believe a typical film thickess for water would be less than 1 micron.

 

[therealkilkenny]

What is the application that you are working with? I am working at the University of Sheffield on a Technique for measuring the oil film thickness in bearings, but also face seals.

Is this any use?