<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<META content="MSHTML 6.00.2900.5803" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV><FONT face=Arial size=2>Dear Sumit, dear all,</FONT></DIV>
<DIV><FONT face=Arial size=2>John Philo seems, addressed the right
problemes of cell leaking !! <STRONG><FONT size=3>1)</FONT></STRONG> Since I
use partly double-</FONT></DIV>
<DIV><FONT face=Arial size=2>sector centerpieces of the age over 30 years, they
are some reasons that a cell may leak at several rotor speeds, even
at<U> zero rpm</U> (waiting for vacuum before run-start.) In
principle I put 2 housing-</FONT></DIV>
<DIV><FONT face=Arial size=2>plug-gaskets even at new centerpieces.
For older centerpiece I put about
5 housing-plug-gaskets</FONT></DIV>
<DIV><FONT face=Arial size=2>so that the housing plug (small screw that we
called 5 $ screw once they cost)) presses tight the (self
cutted ) gasket and prevent liquids to escape (zero rpm) even in such
low amount that you </FONT></DIV>
<DIV><FONT face=Arial size=2>don't see it on the vacuum indicator! (
sure the force should be limited, if not the cell
swell so you will get difficulties install the cell in to the rotor hole). <FONT
size=3><STRONG>2)</STRONG></FONT> In most cases I use Sapphire
Windows, </FONT></DIV>
<DIV><FONT face=Arial size=2>since you can tourqe the cell a bit
tighter then quarz ones. (Older centerpieces are not total
flat,</FONT></DIV>
<DIV><FONT face=Arial size=2>so you flatten them a bit better). An
additional reason is at highspeed SV speeds, that in case of on
sector leaking that causes high pressure, the middle wall breaks and then
usually the quarz window also breaks...<FONT
size=3><STRONG>3).</STRONG></FONT>I use in case of runs <U>not
over</U> 30000 rpm !! usually SE runs</FONT></DIV>
<DIV><FONT face=Arial size=2>double-sector-centerpiece - gaskets, (it
is quite hard to install them and they are very
expensive)</FONT></DIV>
<DIV><FONT face=Arial size=2>those used in alum/metal DS'tors, but it is
possible also if you find the trick to do it, so you
prevent leakages ( as also John menthioned) between the
sectors with all his consequences.</FONT></DIV>
<DIV><FONT face=Arial size=2>yours ariel</FONT></DIV>
<DIV><FONT face=Arial size=2><A
href="mailto:ariel.lustig@bluewin.ch">ariel.lustig@bluewin.ch</A></FONT></DIV></BODY></HTML>