Hi David,
We do something similar here with our 400 Ultrashield. However, the idea of
a steel binder clip makes me a bit nervous. We just pinch and tuck the tubing
into the hole in the hoisting tab (lower left in the photo from Todd).
All the best,
Rick
Richard W. Fitch
Professor, Department of Chemistry and Physics
Councilor, Wabash Valley Section, American Chemical Society
Indiana State University
600 Chestnut Street
Science Building, Rm. S35E
Terre Haute, IN 47809
Phone: (812) 237-2244
Fax: (812) 237-2232
“Do an apparently simple experiment that gives you an important bit of information...”
Julius Axelrod
The love of money is the root of some evil. Fear and insecurity are the root of most of it.
> From: main_at_ammrl.groups.io On Behalf Of Todd Rappe via groups.io
> Sent: Tuesday, January 27, 2026 4:54 PM
> To: main_at_ammrl.groups.io
> Subject: Re: [AMMRL] helium plumbing on vintage Bruker magnets
I have not attempted such a modification, but my general process with fills
is to clamp the tube from the fill port stack (left in your photo) using a
binder clip and vent from the opposite stack (right) the clamp forces all
of the gas to vent out of one stack.
_____________________________________
Todd Rappe
Minnesota NMR Center <nmr.umn.edu >
612-625-9147 (office)
651-321-TODD (rings office and mobile)
612-624-8892 (magnet lab)
On Tue, Jan 27, 2026 at 2:30 PM Vander Velde, David via groups.io wrote:
Hi, I am now involved in managing a Bruker Ultrashield magnet (which I had
previously done decades ago) after a period of managing Ascend magnets. Prior
to the Ultrashield series, every magnet I worked with (Oxford or Spectrospin)
had a cross piece connecting however many helium stacks there were, with a
small one way valve on the single vent.. The Ultrashields came without this
piece, with just Tygon tubing connecting the stacks to a similar one way
valve. With the Ascend series, the cross piece came back, with a much more
robust one way valve which can stay in place during helium fills. (pictures attached)
I took care of Ultrashields for quite a while without understanding why the
cross piece went away, or what the really optimal way was to vent the cold
gas released during a helium fill. The two stacks on the mid field magnets
behave very differently--the one with the fill port and the helium sensor
appeared to be wide open to exiting helium, whereas the other stack was
extensively set up with baffles or other internal structures which impeded
the helium.
I have a very strong preference for filling magnets that feature the cross
piece, where how much helium is exiting through which stack is transparent
to me.
My questions are, has anyone modified their UltraShield with the Ascend style
cross piece? Alternatively, does anyone know of reasons why that would be a
bad idea?
--
Dave VanderVelde
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Received on Wed Jan 28 2026 - 06:52:56 MST