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Subject: Re: Diffusion Pump Cleaning
Date: Feb 06, 1:34 am
Poster: Dave Cooper
On Feb 06, 1:34 am, Dave Cooper wrote:
>I just got my hands on a nice little CVC "Blue Line" diffusion pump. Though on the whole it looks it fair shape, I'd like to clean it before I try to put it to use. Has anyone out there had experience doing this? What solvents are good, etc....
If the interior is not discolored and has no evidence of burned oil, a simple wash out with Acetone, followed by either Isopropanol or Methanol will probably be all you need. Be sure to let the interior dry thoroughly before putting a fresh charge of diff. pump oil. After air drying.. carefully apply a heat gun to the exterior surfaces to bring them up to 100 C or even a little warmer... CAUTION!!! Be sure there is NO liquid solvent inside when you use the heat gun. This "bakeout" desorbs most of the solvent and shortens the prep time after you refill and do the initial pump down.
Allow the pump to cool and fill with the proper diff pump oil for the pump. Be sure not to mix the oils or you will get poor pumping speed.
If you have overheated oil residue, inside.. you have several options. One is to use the hydroxide based oven cleaner to get the ugly stuff out. then follow up with a 5% phosphoric acid soak. Then use the acetone / alcohol sequence, dry out heat gun and you are ready to go.
Hope this is useful.