David,

Sorry to hear of the diff your pump plight.  Edwards advice sounds pretty
good.  I would only add that you might want to finish off with multiple
rinses of ethanol before your 75°C bake.  Acetone disolves Santovac 5
(albeit slowly), but is pretty subborn about hanging around in the diff
pump even after a good long vacuum bake.  Acetone residuals seem to bring
alot of noise to measurements of masses 44, 45, and 46, even after baking.
I would definately replace the viton 'O' rings on the filler ports.

Best of luck!

Bruce

_________________________________________________________
        Bruce H. Vaughn, Stable Isotope Lab
        Institute of Arctic and Alpine Research
        University of Colorado  CB 450
        Boulder, Colorado  80309

        Office: 303-492-7985                 [log in to unmask]
        Lab:  303-492-5495                    FAX: 303-492-6388
_________________________________________________________
>

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.