We have Praxair and they supplies the fittings. Before, we had Airgas and Bruker kindly provided it. Try to contact Bruker.
Ana Gudzon.
________________________________________
From: Stephen Peurifoy [stephen.peurifoy_at_millersville.edu]
Sent: Thursday, March 15, 2012 10:06 AM
To: ammrl_at_ammrl.org
Subject: AMMRL: LHe fills and fittings
Hello all,
I have a couple of (related) questions about liquid helium fills:
First, there seem to be two general LHe dewar pressurization
methods. Some facilities use a rubber "boot" on the outlet of
the transport dewar with a side connection for helium gas.
Other places pressurize through the dewar vent port. Is this
just a handed-down tradition thing or are there reasons for
choosing one method over another?
Second, does anyone know of a supplier for the oddball fittings
involved in this? The transport dewars we get from our supplier
have what appears to be a male 3/4-20 UNEF fitting. The female
nut on our LHe transfer line stinger looks like 7/8-20 UNEF.
I've trawled the internet for hours and haven't found a source
for compatible fittings but maybe I haven't used the right
search terms. There's a 7/8-20 UNEF to 1/2 NPT plastic adapter
in our "boot" so clearly someone makes these. Our cryogen
supplier was no help and none of the plumbing places I've checked
have fittings that size with that fine a thread pitch.
Thanks,
Steve Peurifoy
Chemistry Department
Millersville University of Pennsylvania
Millersville PA
Received on Thu Mar 15 2012 - 14:19:00 MST