From bradshaw at utdallas.edu Thu Mar 25 15:43:38 2010 From: bradshaw at utdallas.edu (Keith Bradshaw) Date: Thu, 25 Mar 2010 14:43:38 -0500 Subject: [labnetwork] LN2 Dewar filling controllers Message-ID: <40190E926F94485B93FE27DCC0304407@campus.ad.utdallas.edu> We had a LN2 electric valve stick during filling and are looking for a better system. What do you use for filling the big LN2 dewars? We are filling from a 3,000 gallon tank. Cordially, Keith Bradshaw Keith Bradshaw 972-883-2099 RL 10 University of Texas at Dallas Clean Room NSERL building -------------- next part -------------- An HTML attachment was scrubbed... URL: From bob at eecs.berkeley.edu Fri Mar 26 15:46:09 2010 From: bob at eecs.berkeley.edu (Bob Hamilton) Date: Fri, 26 Mar 2010 12:46:09 -0700 Subject: [labnetwork] LN2 Dewar filling controllers In-Reply-To: <40190E926F94485B93FE27DCC0304407@campus.ad.utdallas.edu> References: <40190E926F94485B93FE27DCC0304407@campus.ad.utdallas.edu> Message-ID: <4BAD0F01.20603@eecs.berkeley.edu> Keith Bradshaw, I am about to install a Magnatrol 24V direct acting cryogenic fill valve on our fill station. We will preserve our manual shutoff valve and add a 1-hour spring wound timer for fills. We've found fills times for our 160 L cylinders takes about an hour given our bulk tank pressure of 40 psi and expect it to take longer, in the future, when we raise this 3000 gallon tank from 40 to 80 psi (i.e. a larger "flash loss"). It is interesting to read about your experience. I have no experience with electronic direct acting cryogenic valves and bulk fills. I did consider a pilot-operated valve using the tanks N2 pressure as the motive force but I went for the simpler direct acting route using an electromagnetic valve. Choosing 24V AC means I can run a cable to the fill station and avoid a 110V hazard. I'm not looking for any surprises so your warning is appreciated! Bob Hamilton Robert Hamilton University of California at Berkeley Microlab Facilities Manager Rm406 Cory Hall Berkeley, CA 94720-1770 510-642-2716 510-642-2916 (Fax) 510-325-7557 (Cell) bob at silicon2.eecs.berkeley.edu On 3/25/2010 12:43 PM, Keith Bradshaw wrote: > > We had a LN2 electric valve stick during filling and are looking for a > better system. > > What do you use for filling the big LN2 dewars? We are filling from a > 3,000 gallon tank. > > Cordially, > > Keith Bradshaw > > Keith Bradshaw > > 972-883-2099 > > RL 10 > > University of Texas at Dallas Clean Room > > NSERL building > > > _______________________________________________ > labnetwork mailing list > labnetwork at mtl.mit.edu > https://www-mtl.mit.edu/mailman/listinfo.cgi/labnetwork > -------------- next part -------------- An HTML attachment was scrubbed... URL: