Pumps & amp; seals flatness readings

Seal face flatness readings

The following chart describes the patterns you could observe if you looked through an optical flat at a lapped mechanical seal face that was illuminated by a monochromatic light source. For an explanation of how these patterns were formed you can read the paper Reading seal face flatness 6-3on another page in this web site.

I have left the white background to assist you in seeing the patterns a bit easier.

1 Helium light band 2 Helium light bands 3 Helium light bands 4 Helium light bands


  • On February 09, 2018