<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
Tom, Craig, and Dennis:<br>
<br>
Thanks for each of your comments. I should have thought to mention
more about the details of our gases:<br>
<br>
We are using electronic grade HCl specified to be 99.995% pure.
While I think that there is one grade higher, at $1200 a cylinder it
should be pretty good ...<br>
Note: this is also set up with a DISS fitting (CGA 634 for HCl).<br>
<br>
For our purge gas we use 10% He in a balance of nitrogen, again with
a DISS fitting. Each of the component gases is of UH grade that, I
believe translates in to:<br>
<br>
<font face="sans-serif" size="2">Nitrogen:</font>
<br>
<br>
<font face="sans-serif" size="2">02
< 1ppm</font>
<br>
<font face="sans-serif" size="2">H20 < 3ppm</font>
<br>
<font face="sans-serif" size="2">THC < 0.5ppm</font>
<br>
<br>
<font face="sans-serif" size="2">Helium</font>:<br>
<br>
<font face="sans-serif" size="2">02
< 1ppm</font>
<br>
<font face="sans-serif" size="2">H20 < 2ppm</font>
<br>
<font face="sans-serif" size="2">THC < 0.5ppm</font>
<br>
<br>
<font size="2">After a cylinder change, we do a He leak check of the
purge gas following each cylinder change. I think that we are
currently using 30 purge cycles both pre- and post-purge ... it
sounds as if that should be bumped up. While I believe that we
have hastelloy running between cabinet and tool, I believe that
the components in the panel are all SS ... but I believe are
electopolished to <br>
<br>
We have a manifolded two-cylinder (plus purge) cabinet that
supplies an epi reactor. It is not uncommon to use a 60 pound
cylinder of HCl in a period of 1-2 weeks ... so, we unfortunately,
have a number of chances for problems each year.<br>
<br>
Thanks again for all of your input,<br>
<br>
John<br>
<br>
</font>
<br>
<div class="moz-cite-prefix">On 6/6/2014 1:07 PM, Tom Britton wrote:<br>
</div>
<blockquote
cite="mid:9820889A26AAC34EBEB01D62DFCEEB2E01157FE7@P3PWEX2MB006.ex2.secureserver.net"
type="cite">
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1">
<meta name="Generator" content="Microsoft Word 14 (filtered
medium)">
<!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]-->
<style><!--
/* Font Definitions */
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:"Arial Narrow";
panose-1:2 11 6 6 2 2 2 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{mso-style-priority:99;
mso-style-link:"Plain Text Char";
margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Balloon Text Char";
margin:0in;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";}
span.PlainTextChar
{mso-style-name:"Plain Text Char";
mso-style-priority:99;
mso-style-link:"Plain Text";
font-family:"Calibri","sans-serif";}
span.BalloonTextChar
{mso-style-name:"Balloon Text Char";
mso-style-priority:99;
mso-style-link:"Balloon Text";
font-family:"Tahoma","sans-serif";}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:935091519;
mso-list-type:hybrid;
mso-list-template-ids:-251645666 67698689 67698691 67698693 67698689 67698691 67698693 67698689 67698691 67698693;}
@list l0:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;
font-family:Symbol;}
@list l0:level2
{mso-level-number-format:bullet;
mso-level-text:o;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;
font-family:"Courier New";}
@list l0:level3
{mso-level-number-format:bullet;
mso-level-text:\F0A7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;
font-family:Wingdings;}
@list l0:level4
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;
font-family:Symbol;}
@list l0:level5
{mso-level-number-format:bullet;
mso-level-text:o;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;
font-family:"Courier New";}
@list l0:level6
{mso-level-number-format:bullet;
mso-level-text:\F0A7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;
font-family:Wingdings;}
@list l0:level7
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;
font-family:Symbol;}
@list l0:level8
{mso-level-number-format:bullet;
mso-level-text:o;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;
font-family:"Courier New";}
@list l0:level9
{mso-level-number-format:bullet;
mso-level-text:\F0A7;
mso-level-tab-stop:none;
mso-level-number-position:left;
text-indent:-.25in;
font-family:Wingdings;}
ol
{margin-bottom:0in;}
ul
{margin-bottom:0in;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
<div class="WordSection1">
<p class="MsoPlainText"><span style="font-family:"Arial
Narrow","sans-serif";color:#1F497D">Hi John,<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="font-family:"Arial
Narrow","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="font-family:"Arial
Narrow","sans-serif";color:#1F497D">Sorry to
hear about your HCl issue. As we all know, HCl is very
difficult to manage once it escapes. Neutralizing is seldom
effective in a clean room environment, and replacement of
metal components that have come in contact with the HCL is
the proper way to keep it from spreading. If the proper
leak test procedures are in place, one thing that could be
causing the leaks is residual moisture that may be present
due to either low quality purge gas or inadequate purging.
<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="font-family:"Arial
Narrow","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoPlainText" style="margin-bottom:6.0pt"><span
style="font-family:"Arial
Narrow","sans-serif";color:#1F497D">To solve
the problem of how to prevent leaks with HCl and other
corrosives these are the questions I would start with.
<o:p></o:p></span></p>
<p class="MsoPlainText"
style="margin-left:.5in;text-indent:-.25in;mso-list:l0 level1
lfo1">
<!--[if !supportLists]--><span
style="font-family:Symbol;color:#1F497D"><span
style="mso-list:Ignore">·<span style="font:7.0pt
"Times New Roman"">
</span></span></span><!--[endif]--><span
style="font-family:"Arial
Narrow","sans-serif";color:#1F497D">What is
the quality of the purge gas?
<o:p></o:p></span></p>
<p class="MsoPlainText"
style="margin-left:.5in;text-indent:-.25in;mso-list:l0 level1
lfo1">
<!--[if !supportLists]--><span
style="font-family:Symbol;color:#1F497D"><span
style="mso-list:Ignore">·<span style="font:7.0pt
"Times New Roman"">
</span></span></span><!--[endif]--><span
style="font-family:"Arial
Narrow","sans-serif";color:#1F497D">Are you
using a purifier on the purge gas?
<o:p></o:p></span></p>
<p class="MsoPlainText"
style="margin-left:.5in;text-indent:-.25in;mso-list:l0 level1
lfo1">
<!--[if !supportLists]--><span
style="font-family:Symbol;color:#1F497D"><span
style="mso-list:Ignore">·<span style="font:7.0pt
"Times New Roman"">
</span></span></span><!--[endif]--><span
style="font-family:"Arial
Narrow","sans-serif";color:#1F497D">Is H2O or
O2 analysis done on the gas system prior to gas
introduction?
<o:p></o:p></span></p>
<p class="MsoPlainText"
style="margin-left:.5in;text-indent:-.25in;mso-list:l0 level1
lfo1">
<!--[if !supportLists]--><span
style="font-family:Symbol;color:#1F497D"><span
style="mso-list:Ignore">·<span style="font:7.0pt
"Times New Roman"">
</span></span></span><!--[endif]--><span
style="font-family:"Arial
Narrow","sans-serif";color:#1F497D">How many
purge cycles on gas line prior to gas introduction?
<o:p></o:p></span></p>
<p class="MsoPlainText"
style="margin-left:.5in;text-indent:-.25in;mso-list:l0 level1
lfo1">
<!--[if !supportLists]--><span
style="font-family:Symbol;color:#1F497D"><span
style="mso-list:Ignore">·<span style="font:7.0pt
"Times New Roman"">
</span></span></span><!--[endif]--><span
style="font-family:"Arial
Narrow","sans-serif";color:#1F497D">How many
purge cycles post cylinder change are being done?
<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="font-family:"Arial
Narrow","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="font-family:"Arial
Narrow","sans-serif";color:#1F497D">If you
want, I can set up a conference call with Troy Reese, who
was the gas systems manager at ON Semi before he came to us,
and we can go over these questions. Troy is very
knowledgeable in these situations and we would be happy to
help wherever possible. He is also presenting with you at
the Bootie Camp coming up at the UGIM conference, so we can
talk about it there as well if necessary.<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="font-family:"Arial
Narrow","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="font-family:"Arial
Narrow","sans-serif";color:#1F497D">See you
at Harvard.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial
Narrow","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial
Narrow","sans-serif";color:#1F497D">Thank
you!<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial
Narrow","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial
Narrow","sans-serif";color:#244061">Tom
Britton</span><span style="font-family:"Times New
Roman","serif";color:#244061"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial
Narrow","sans-serif";color:#244061">Director
of Sales</span><span style="font-family:"Times New
Roman","serif";color:#244061"><o:p></o:p></span></p>
<p class="MsoNormal"><i><span
style="font-size:14.0pt;font-family:"Arial
Narrow","sans-serif";color:#244061">Critical
Systems, Inc.</span></i><span
style="font-size:14.0pt;color:#244061"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial
Narrow","sans-serif";color:#244061">Direct:
208-890-1417<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Arial
Narrow","sans-serif";color:#244061">Office:
877-572-5515<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:12.0pt;color:#1F497D"><a
moz-do-not-send="true"
href="http://www.criticalsystemsinc.com/"><i><span
style="font-family:"Arial
Narrow","sans-serif";color:blue">www.CriticalSystemsInc.com</span></i></a></span><i><u><span
style="font-size:12.0pt;font-family:"Arial
Narrow","sans-serif";color:#1F497D"><o:p></o:p></span></u></i></p>
<p class="MsoNormal"><i><u><span
style="font-size:4.0pt;font-family:"Arial
Narrow","sans-serif";color:#1F497D"><o:p><span
style="text-decoration:none"> </span></o:p></span></u></i></p>
<p class="MsoNormal"><span style="color:#1F497D"><img
id="Picture_x0020_1"
src="cid:part2.07020906.01020200@stanford.edu" alt="logo
for email signature png" border="0" height="38"
width="196"></span><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">-----Original Message-----<br>
From: <a class="moz-txt-link-abbreviated" href="mailto:labnetwork-bounces@mtl.mit.edu">labnetwork-bounces@mtl.mit.edu</a>
[<a class="moz-txt-link-freetext" href="mailto:labnetwork-bounces@mtl.mit.edu">mailto:labnetwork-bounces@mtl.mit.edu</a>] On Behalf Of John
Shott<br>
Sent: Thursday, June 05, 2014 1:09 PM<br>
To: <a class="moz-txt-link-abbreviated" href="mailto:labnetwork@mtl.mit.edu">labnetwork@mtl.mit.edu</a><br>
Subject: [labnetwork] Anhydrous HCl after it escapes ...</p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">Labnetwork Community:<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">Sooner or later, it seems, anhydrous
hydrogen chloride (or a number of equally corrosive materials)
is going to escape. At least that is our experience at the
Stanford Nanofabrication Facility. Despite our best efforts
to use quality components, do proper leak checking, etc., it
seems as if we end up with a leak either in a gas cabinet or
in a tool near a mass flow controller. At that point,
anything near the site of the original leak has been covered
with now moisture-laden hydrogen chloride ... which, I
believe, is far more corrosive than the original anhydrous
material.<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">For those of you who have encountered
similar situations, how do you recover or what to you
replace? Do you have effective means of neutralizing those
metal surfaces? Do your replace VCR gaskets with
thicker-than-normal or grooved "super gaskets"? Do you
replace the entire assembly? Do you leak check, put back in
service, and pray?<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">Thanks for sharing your experience and
insights,<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">John<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">_______________________________________________<o:p></o:p></p>
<p class="MsoPlainText">labnetwork mailing list<o:p></o:p></p>
<p class="MsoPlainText"><a moz-do-not-send="true"
href="mailto:labnetwork@mtl.mit.edu"><span
style="color:windowtext;text-decoration:none">labnetwork@mtl.mit.edu</span></a><o:p></o:p></p>
<p class="MsoPlainText"><a moz-do-not-send="true"
href="https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork"><span
style="color:windowtext;text-decoration:none">https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork</span></a><o:p></o:p></p>
</div>
</blockquote>
<br>
</body>
</html>