DCHAS-L Discussion List Archive
Date: Thu, 12 Nov 2009 10:51:03 -0500
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: ILPI <info**At_Symbol_Here**ILPI.COM>
Subject: Re: Hood Sash Cables
In-Reply-To: <742A43346DE3BB47842910A69D6707C10DCDACC876**At_Symbol_Here**EX071012.bemisco.net>
Does anyone have any information on cable breakage, or has
anyone heard of an incident of both sash cables breaking at the same
time causing the sash to completely
fall?
Someone
commented earlier that the chance of both cables breaking at the same
time is essentially zero. I
agree.
However, there is (unfortunately) a
reasonably good chance (in academic laboratories in particular) that
when one cable fails and the hood sash becomes "sticky" or hard to move
that the problem will simply be lived with rather than corrected,
particularly when a hood is not used regularly or it is not "assigned"
to one person in particular. In those cases, the hood is being
operated on one cable and the remaining one is stressed and likely to
fail even faster. Which could easily set up the catastrophic
failure scenario.
In my academic career I
encountered probably 2 hoods that did not have working cables, both in
"overflow" or generally unoccupied labs.
A
specific recommendation I'd make is adding "hood sashes operating
properly" to your weekly/monthly lab safety checklist which should
already cover other aspects of safe hood
operation.
Rob Toreki
