LALman wrote:
I usually wipe out the grove with a kimwipe dampened with P&T methanol and then gently wipe the o-ring the same way to get it clean. Sometimes the o-ring stretches a bit doing that and it does not want to seat uniformly all around. So I run a dry kimwipe around the seated ring back and forth to smooth it into place.
I've been advised in the past to put APIEZON L grease on a kimwipe and rub it together so its absorbed into the kimwipe then lightly grease the large o-ring. Followed by wiping off as much as possible with a kimwipe before reseating it. The APIEZON L grease is supposed to be a good "getter" for residual offgassing in the vacuum chamber.
Other operators say never never do this.
I have always used Apeizon L, as far back at the 5970 days. I still have a tube given to me by our Agilent service engineer more than 20 years ago. Never had a problem with it. I usually but just a bit on my finger tips and rub them together, then slide the o-ring through my fingers, this way I can feel if there are any nicks, scratches, or contaminates like lint on the surface. Then I pull it through while holding it in a kemwipe to remove any excess before putting it back in.
Our roughing pumps are old (more than 10 years). We changed the oil in one pump but it failed shortly after we turned it on in the initial start up so we went to pump two (changing oil again before use) and I assumed it was good since we were able to get our turbo pump to turn on.
Are they the small E2M1.5 or equivalent pumps that are small enough to fit up under the vacuum chamber? I have never had one of those last very long and replaced all of mine with Edwards E2M2 pumps scavenged from our old 5970s and 5971/72s. Many of them are 30 years old and have run non stop the whole time with only an annual oil change, no other maintenance. Maybe that is why they made them obsolete
because they were too well built.