Here are two useful safety related items for use during magnet fills.
LN2 stainless steel transfer line as adapted from one I saw used by Magnex. The
Teflon ferrules are absolutely necessary to prevent damaging the LN2 port. Also
remember to jus barely snug up the nut of the elbow once you place it on the LN2
port. These parts are for use on 0.5" ports. The 13 mm Bruker ports require
modifying the elbow parts to fit unless one can find a 13 mm tube by 3/8 female
NPT elbow.
Stainless steel transfer line
1 each Western Enterprises CGA-295 Nitrogen Hose 72" part number WMH-2-16 ~ $197
Other hose lengths are available. See website
1 each CGA-295 to 3/8 male NPT adaptor part number F-32 ~ $5
http://www.westernenterprises.com/enterprises/PDFS/wi33.pdf
Swagelok
1 each Ferrule set Teflon includes 1 back and one front ferrule T-810-SET ~$3
1 each Stainless steel elbow SS-810-8-6 For 1/2" tube with female 3/8" NPT ~$25
To eliminate the fumbling with the cross bar vent during a helium fill. I
adapted the idea from another lab that I can't remember. They used a 0.5"
standard ball valve that you can buy at any plumbing supply store. After
consulting with Walter Osgood from the Bruker Magnet group, I decided to use
this valve. The construction is over-kill for the application, but I wanted a
1" diameter bore for the valve AND a lower temperature lubricant and stem seal
for the valve. The L65 valve specified is rated to -53C. While this may not
seem low enough, you will be able to quickly CLOSE the valve after a "normal"
helium fill without resorting to using a heat gun. The idea is that you can
then minimize the amount of time the magnet is exposed to air. We have used
this setup at Bayer on seven magnets (3-Magnex and 4-Oxford) with out a problem.
The caveat is not to fill too fast nor too slowly or you risk freezing the
valve. I always disliked fumbling with the clamps and o-rings while holding the
transfer line spewing liquid helium out the end. This solved the problem and
also allows a large enough opening if there is a quench.
Parts for magnet vent valve
The brass valve from Swagelok is a low temperature unit with Teflon seals and 1"
diameter female threads.
B-L65TF16 ~ $155
The parts below are from Nor-Ca1
1 NW-25B-1 MPT 1" to NW25 adapter ~$80
1 3T-NW-25B 1" Tee ~$75
2 NW-25-Cp clamp ~$7
2 NW-25-CR-AV viton "o"-ring $6
Peter C. Demou Phone: 203-812-2967
Bayer Pharmaceuticals Corporation FAX: 203-812-3655
400 Morgan Lane email peter.demou.b_at_bayer.com
West Haven, CT 06516
Received on Mon Apr 26 2004 - 10:24:41 MST