Date: Fri, 5 Mar 2010 15:22:06 -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: Stanley K Lengerich <LENGERICH_STANLEY_K**At_Symbol_Here**LILLY.COM>
Subject: Re: Emergency purge mode for fumehood
In-Reply-To: <B25C370F3F6ADF4D94FE33CE1698D1B10714675B**At_Symbol_Here**MBX03.stf.nus.edu.sg>


The emergency purge is a useful feature for many situations, and can be 
very helpful in purging smoke from a fire in the hood. While it can fan 
the flames, this is not the root cause of your problem. The flexible 
connection would have melted sooner or later; the purge probably just sped 
up that process a little. Fume hoods should never be connected with 
flexible, nonfire-rated duct. It's best to hard duct everything with steel 
duct, but if you absolutely have to have a flex connection, they do make 
some flexible steel connections, they're just not as flexible as most 
non-steel ones.

Regards,

Stan


The emergency purge is a useful feature for many situations, and can be very helpful in purging smoke from a fire in the hood. While it can fan the flames, this is not the root cause of your problem. The flexible connection would have melted sooner or later; the purge probably just sped up that process a little. Fume hoods should never be connected with flexible, nonfire-rated duct. It's best to hard duct everything with steel duct, but if you absolutely have to have a flex connection, they do make some flexible steel connections, they're just not as flexible as most non-steel ones.

Regards,

Stan

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