AMMRL: summary on pump maintenance of pumped magnet system

From: Ma, Dejian <dejma_at_indiana.edu>
Date: Tue, 20 Sep 2011 17:03:54 -0400

Thanks to all who replied my previous message. I appreciate it.

Below please find the replies I got. In brief, it seems necessary to do
the pump maintenance of the pumped magnet system although it is the
helium that's being pumped. Guess I will have to learn some new skill,
I never even did the oil change for my car myself before. :-)

Original message:

For those who have knowledge on pumped magnet system, could you please
share your pump maintenance experience? We have two BUSCH pumps for our
pumped 800 system. How do you change the oil and/or filter? Do you
have the job done by the company or do the job yourselves? How often? I
couldn't find relevant information from the archive.

Summary of replies:

---
I was told we shouldn't need to do this because it is He that is being pumped.
I.e., no air/O2 means the pump oil doesn't degrade and thus doesn't need to be
changed. If you find out different, I would love to know.
---
I just monitor the oil level and I do not change oil.
When the oil level is low, I will add some more.
A summary of your response is appreciated.
---
I have two Edwards pumps - one constantly working and one spare. While
changing oil once in three months in the working one, I let the spare 
run for 10-15 min and change oil in it once a year. Oil and mist 
filters have to be changed every three months, but I usually let them 
work longer - it depends on how much oil your pump spits out.
...Pump parts experience tear and wear, so does the oil. A good 
indicator for its quality is its color...
---
I have the same Pumped 800 and Busch pumps.  I do the oil and filter changes
myself.  the internal filter is tricky, but not impossible.  I change the oil
every 6 months or so. and replace the filters once a year.
...
The oil definitely turns very dark in color.  the heat of the pump use has an
affect, so I choose to err on the side of caution and regularly change the oil
and filters.
---
We have Edwards pumps on our Oxford 800.  We change the oil after 4 months
of operation and have the pumps rebuilt by our machine shop after 20 months
of operation.  Once (in ~10 years) we've had to replace a pump because it
didn't perform satisfactorily after rebuild.
We're having two sub-cooled Bruker systems installed right now and I was
told that the recommendation for their pumps is to add oil as needed to
maintain the proper level, but otherwise just let the pump run until it dies
and then replace.
---
We have a Bruker 800 pumped magnet. Bruker came and took care of our pumps
when they leaked. Every time I do my helium fill (~ every 4/5 weeks) I check
if the pumps are leaking and if the oil is still within the recommended
limits. ...
---
Thanks.
Dejian

Received on Tue Sep 20 2011 - 11:03:56 MST