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Date: Fri, 23 Sep 2011 09:00:23 -0400
Reply-To: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: Ken Kretchman <ken_kretchman**At_Symbol_Here**NCSU.EDU>
Subject: Re: 4% hydrogen mixture
Comments: cc: Eugene_Ngai**At_Symbol_Here**comcast.net
In-Reply-To: <A4BDFFCAC336824B8501F8FA6E1DA2D4AC51F65585**At_Symbol_Here**EXCHMBA.ornl.gov>
While I have been long operating with the understanding that this mixture
is well below a flammable concentration, based on company testing and
other data also from long ago, I am copying Eugene Ngai of Chemically
Speaking who has a great deal of experience with gas suppliers and CGA
with extends over many years...
thanks
Ken
>>> "Jeskie, Kimberly B." 9/23/2011 8:14 AM >>>
Long story short, the reason I ask this question is that we have a long
standing debate with our research community who feel strongly that they
have chosen the 4% mixture because it gives them the reducing environment
they need while limiting the hazard, that's why they use it. The DOT
classification is based on P-32 and the building codes (which is where the
debate starts) generally site DOT as the go to place for deciding how to
class materials for the quantities allowed inside buildings. That's where
we keep coming up against a logistics nightmare. No one can agree on how
to account for this mixture and most everyone agrees that using the full
volume of a 4 % mixture just doesn't make common sense.
One of our Fire Protection Engineers has suggested that the sources of
information we use to make these decisions may be dated and an analysis
may be the ticket to put this issue to bed. The P-23 pamphlet references
Bureau of Mines Bulletin 503-1952 and much of the 503 date is based on
simple, ad hoc tests on an apparatus dating back to the 1920s. Some of
the data is based on earlier work dating back to the 1870s and 1880s. DOT
references and accepts ASTM E-681 to classify flammability of gases.
So...we're debating on whether or not to test the mixture under this newer
standard, and it sure would be great if it has already been done.
Kim
Kimberly Begley Jeskie, MPH-OSHM
Operations Manager
Physical Sciences Directorate
Oak Ridge National Laboratory
(865) 574-4945
-----Original Message-----
From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**list.uvm.edu] On Behalf Of
Todd Perkins
Sent: Thursday, September 22, 2011 7:05 PM
To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
Subject: Re: [DCHAS-L] 4% hydrogen mixture
Do you mean test the mixture for flammability per CGA publication P-23?
My understanding is that the data is based on experimental observatio
n as well as calculation. I've never had reason to question the data. Have
you observed something different?
Todd Perkins
Regional Safet Director
Airgas Mid America
Thanks,
Todd
- Sent from my mobile phone
On Sep 22, 2011 11:41 AM, Jeskie, Kimberly B. <jeskiekb**At_Symbol_Here**ORNL.GOV>
wrote:
Has anyone actually tested a 4% hydrogen/ 96% argon mixture using ASTM
E-681, as opposed to just taking the P-23 data or the Bureau of Mines
Bulletin 503-1952 at face value? Kim Kimberly Begley Jeskie,
MPH-OSHMOperations ManagerPhysical Sciences DirectorateOak Ridge National
Laboratory(865) 574-4945
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