Anne, I can tell you from my personal 10 years of university experience, I've nev er seen this happen (that does NOT mean it won't or can't - just that I've not seen it). I've had the tube break off (perhaps twice, but only once th at I can for sure remember) right at the fill tube, though, and I can tell you I was far more concerned with the integrity of the can flange at that p oint than whether or not I was getting liquid nitrogen on me (which I wasn' t...) That being said, there is a very good argument to be made for slow fills. This tends to be more efficient, and permit a more complete fill (which eit her translates into fewer fills if you fill at a specific level, or a large r reserve if you fill on a specific time schedule). If, as in our case, a graduate assistant or dedicated staff member is doing the fill, it does no good to rush the fill (vendors, on the other hand, have multiple deliveries to make in a single day and don't have the time to spare to do slow fills) . My vote is for the slow fill. Brad Norwood Bradley K. Norwood, PhD Laboratory Director Arista Laboratories 1941 Reymet Road Richmond, VA 23237 (804) 271-5572 ext. 307 (804) 641-4641 (cell) brad.norwood**At_Symbol_Here**aristalabs.com ************** D i s c l a i m e r *************** This e-mail message is confidential and may contain legally privileged info rmation. If you are not the intended recipient you should not read, copy, d istribute, disclose or otherwise use the information in this e-mail. Please also telephone us (804-271-5572), or fax us (804-271-5594), immediately an d delete the message from your system. E-mail may be susceptible to data co rruption, interception and unauthorized amendment, and we do not accept lia bility to such corruption, interception or amendment or the consequences th ereof. -----Original Message----- From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**list.uvm.edu] On Behalf Of An ne Skinner Sent: Thursday, January 29, 2009 3:15 PM To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU Subject: [DCHAS-L] LN2 and NMR We are involved in a discussion, rapidly getting acrimonious, about the best way to fill an NMR with LN2. One faction wants to fill as rapidly as possible; the other very slowly. The safety issue is as follows. Eventually the rubber hose used in filling will split. When this happens, if the fill rate is rapid the LN2 will spatter around, possibly onto anyone supervising the fill, especially as they try to turn off the flow. Has anyone any experience as to whether this is actually a threat? Thank you -- Anne R. Skinner -- /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ Dr. Anne Skinner Chemistry Department, Williams College 47 Lab Campus Drive Williamstown, MA 01267 anne.r.skinner**At_Symbol_Here**williams.edu Phone: (413) 597-2285 Fax No: (413) 597-4116 /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ /O\ Si Si Si Si Si Si Si Si Si Si Si Si Si Si Si \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/ \O/
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