From: ILPI <info**At_Symbol_Here**ILPI.COM>
Subject: Re: [DCHAS-L] Utility panel modification inside fume hood
Date: November 8, 2012 10:21:35 AM EST
Reply-To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
As a former researcher who set up several labs, I have a couple comments.
1. Careful with drilling holes - older hoods (80's vintage and earlier) are probably made with asbestos-containing transite and even newer ones may contain crystalline silica.
2. Coming in through the side panel shouldn't pose any issues - it's how some pre-plumbed hoods do it. Obviously, you can consult with the hood manufacturer.
3. Schlenk lines etc. that need heavy wall 1" ID vacuum hose to operate are a bit tricky. Usually, the pumps are located in the cabinet below the hood or on the floor, and the hose angles and sink locations do not permit very good options for coming in the side. You could plumb around those locations, but if there is ever any suck-back from the vacuum system, that impromptu manifold will be impossible to clean, troubleshooting leaks is not easy, and it provides that much more space to pump down and possible dry/degas. The shortest possible path is best.
My labs had wood cabinets under the hoods with sinks to the side. Our solutions was to modify the air foil on my hoods with a Dremel tool so the hoses could come in under the sash but still close all the way. Of course, this causes a small disturbance in the airflow pattern. Another option is to come up through the floor of the hood, but if you just drill a hole and caulk it, you have to worry about spill containment and leaks over time. So the best solution may be to mount some sort of floor flange which extends up above the floor surface and hook hoses onto that rather than threading a hose the whole way..
In fact, thinking about that some more, I'd use a flange with KF (QF) quick-connect fittings on one or both ends, so the researcher could *easily* disconnect the hose from the top or bottom and be assured that the connections are vacuum-tight (as opposed to the 'ole radiator clamp method). The bottom hose to the pump could be an all-metal bellows hose if the pump has the same kind of fitting, which is common on most modern direct drive pumps. Here's some KF flange info if you've never seen those before: http://www.lesker.com/newweb/flanges/flanges_technicalnotes_kf_1.cfm?pgid=0
If you can come in through a side wall of the hood, I'd go with the same idea. Blank flanges are available to cap the opening if the pump is not connected.
If you do anything requiring caulk, you may want to consider using an intumescent fire-rated caulk.
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On Nov 8, 2012, at 9:26 AM, Mary Ellen A Scott wrote:
Has anyone ever altered their their fume hood? Here's my issue:
Many of our researchers use a vacuum pump under the fume hood and plumb the vacuum hose through the utility panel in order to connect to the glassware inside the work area.
This leaves the panel off or ajar inside the hood disrupting the vortex and permitting harmful vapors to enter inside the hood and possibly the surrounding area.
We would like to drill a hole into the utility panel to permit vacuum hose to enter snugly and permit the hood to function properly..
Would there be any special safety concerns in cutting out a hole in the panel due to the while poly resin material?
Would you have a better idea on how to get the hose into the hood?
We have drilled through the work platform in the past but most researchers use the utility panel entry. It seems that entry through the front of the hood interferes with worker use, leaves sash open and takes up more space.
Thanks in advance for any advice.
Mary Ellen Scott, PhD.
Safety Specialist II
Case Western Reserve University
EHS - Environmental Health and Safety
Service Building 1st Floor Rm 113
2220 Circle Dr.
Cleveland, OH 44106-7227
"There is no science without fancy and no art without fact" =96 Vladimir Nabokov (1899-1977)
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