[labnetwork] BCL3 - Gas Line Heaters and Protocols

[Dennis Grimard]

Dean:

I would add the following comments: (1) limit the number if 90 degree weldments ... Use large radius bends whenever possible, (2) use close source supplies (place low vapor pressure gas bottles in close proximity to the tool), (3) refrain from using a single source to supply more than one tool, and (4) minimize secondary enclosures with exhaust air flow (VMB's).

I developed these rules of thumb while at IBM ... For production tools they are essential for a reliable supply to your tools.  In a research environment they are good suggestions.  

Heating is always an option.  I would start with simple insulation first.  Watlow may make heat jackets specifically designed for lines (they make a large line of heat jackets for pump vacuum lines).  They may not make them anymore but they did years ago ... There are other companies that may still make them.

Lastly, the demand of the line is important too.  That is, low flow conditions minimize the impact of not following these rules because the line acts as a supply as the gas condenses.  As long as the flow is low the condensed gas will just revaporize to meet the need.

Dennis S Grimard, Ph.D.
Managing Director
Lurie Nanofabrication Facility
1246D EECS Bldg
University of Michigan
Ann Arbor, MI 48103

(734) 368-7172 Cell

On Aug 26, 2013, at 3:09 PM, Dean Sutter <ds120 at gatech.edu> wrote:

> Hello,
> 
> AT GT Nano we have a hard plumbed BCL3 line coming from a central gas room, running several hundred feet into the sub fab eventually connecting to the tools.
> 
> We have been internally debating the necessary protocols and physical installations necessary  to ensure a safe and properly functioning delivery mechanism.
> 
> These discussions have included the elimination of the central approach, replaced with a local gas cabinet and shorter runs since maintaining and being able to monitor line heaters on a several hundred foot of line, buried in plumbing up in the ceiling  is our primary concern.
> 
> So, we are seeking a benchmark from existing facilities that use BCL3.
> 
> Anyone care to volunteer to explain their installation and operating/safety protocols?
> 
> Thanks
> 
> -- 
> Dean A. Sutter
> Associate Director,
> Research Operations and Industry Engagements
> 
> dean.sutter at ien.gatech.edu
> 404 894 3847 - Office
> 404 558 1844 - Cell
> www.ien.gatech.edu
> 
> 
> 
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