>I am seeking advice on cleaning solvents and procedures to remove diffusion
>pump oil (Santovac 5) from the pipework of a mass spectrometer
>(VG/Micromass PRISM SeriesI).    The chilled water line that cools the
>Diffstaks broke and the thermal trip failed to turn the diffusion pump
>heaters off, so the Diffstaks remained hot for 8 hours with no circulation
>of cooling water.  After removing both the source and collector Diffstaks
>(150L/s), there was evidence of condensation of Santovac on the baffles in
>the pipework leading to the collectors.  The baffles in the pipework under
>the source did not have visible evidence of diff pump fluid and the source
>and source housing visually appeared to be clean.  The pipework containing
>the inlet and changeover diffusion pumps (40 L/s) was contaminated with
>diff pump oil.  Has anyone had experience with such a calamity and what is
>the best way of going about cleaning the contaminated pipework.  Edwards
>recommends cleaning with GENKLENE (stabilized trichloroethane) followed by
>rinsing with acetone and baking at 75 oC.  Any advice as to how to proceed
>would be most appreciated.  Also, has anyone replaced their diffusion pumps
>with turbos on an older model PRISM?
>
>Grieving in Gainesville,
>David Hodell
>
>David Hodell
>Professor of Geology
>University of Florida
>P.O. Box 117340
>Gainesville, FL  32611-7340
>http://ess.geology.ufl.edu/hodell/hodell.html
>
>Please Note: My new e-mail address is [log in to unmask]
>All mail to the old address will be forwarded to the new one.

David,

I have same problems with my VGs - (although have not experienced oil
backing up like you - thank god) - the heaters just don't shut themselves
of, they keep cycling.  I suggest putting in a breaker that shuts the
heaters off when the cooling water is off.  You could also install a water
pressure sensor that shut the diffs of at least temporarily.  In case of
short water shut down, the presurre valve would reactive the diff heaters.

Best luck,

Hal Karlsson


Dr. Haraldur R. Karlsson
Associate Professor of Geosciences
Deptartment of Geosciences
Texas Tech University
Box 41053
Lubbock, TX 79409, USA

(806)-742-3130 voice
(806)-742-0100 fax