From shott at stanford.edu  Tue Apr 12 14:52:45 2011
From: shott at stanford.edu (John Shott)
Date: Tue, 12 Apr 2011 14:52:45 -0700
Subject: DCS Problems ....
Message-ID: <4DA4C9AD.6010702@stanford.edu>

DCS Users:

As you may be aware, we currently do not have DCS available for these 
critical tools.  Yesterday morning, we found that the cylinder heater 
that keeps the DCS sufficiently warm to keep adequate vapor pressure had 
gotten too hot ... 28C rather than 18C.  That was enough that when DCS 
got into the regulator and gas panel (which is closer to 18C) we got 
liquid condensation.

In these cases, it is best to use the onboard venturi vacuum generator 
to pump this out to make sure that there is no liquid trapped in the 
delivery line (which will result in erratic flow and flow faults).  
Unfortunately, the burn box that treats the effluent from the venturi 
has developed blockage and is in need of a thorough cleaning.  We will 
take that opportunity to replace the quartz liner and heater element 
that will avoid a future problem.

We are currently dis-assembling, thoroughly cleaning, and reassembling 
that burn box.  We are hopeful that we may have this unit fully cleaned 
and rebuilt by the end of business tomorrow.

We apologize for this outage, but will hope to be back in service soon.

Let me know if you have any questions,

John



From shott at stanford.edu  Wed Apr 13 15:51:24 2011
From: shott at stanford.edu (John Shott)
Date: Wed, 13 Apr 2011 15:51:24 -0700
Subject: DCS service restored ....
Message-ID: <4DA628EC.4080907@stanford.edu>

Fans of tools that use DCS:

I am pleased to report that the DCS service has been restored following 
a complete rebuild of the burn box that services the toxic/flammable gas 
vault.

I'd like to thank Mike Dickey, Ray Seymour, Ted Berg, Maurice Stevens, 
and Mary Tang for all jumping in to help with various aspect of this 
project so that we could effect this rebuild in a timely fashion.

If you have never seen or dealt with the insides of a burn box that is 
used as an abatement system for a facility such as ours, you should know 
that this is unpleasant and potentially hazardous work.  The materials 
found inside a burn box are typically toxic, corrosive, and often burst 
into flames when exposed to air.

I'm sure that the above members of "Team Burn Box" would appreciate a 
word of thanks the next time that you see them.

Happy processing,

John