1/4” copper also works and you can get it at Home Depot and
it’s malleable
David
Associate Professor
Dept. Of Pharmacology
University of Colorado
School of Medicine
Tel (303)-724-3600
On Apr 1, 2026, at 11:58 AM, Sameer Al-Abdul-Wahid via groups.io wrote:
Dear AMMRL,
We’ve been operating our “all‑metal” helium
recovery system for almost three years with very good results. One minor issue
we continue to encounter is the accumulation of ~20 mL of water in our
purifier every few months.
Our magnet‑side connections are shown in the attached photo. During
a fill, we open the blue‑handled valve to provide a high‑f
low path directly to the recovery system. Otherwise, that valve remains closed
and boil‑off helium exits through the upper Tygon tube, passes through
the flow meter, and returns to the recovery system via the lower Tygon tube.
The magnet is protected by a downstream check valve.
We suspect that the Tygon tubing and/or the associated fittings may be the
source of the water ingress. We are therefore considering replacing the Tygon
with 1/4" stainless steel (Swagelok) tubing & fittings. As part of the revision,
we also plan to add a three‑way valve to vent the magnet.
If anyone has experience with similar issues or recommendations, I would be
grateful for your input. I’m happy to compile a summary for the group.
Thanks for your time,
Sameer
--
Sameer Al-Abdul-Wahid, Ph.D.
Manager, Nuclear Magnetic Resonance Centre <
http://nmr.uoguelph.ca/ >
University of Guelph
519-824-4120 x58914 / s.wahid_at_uoguelph.ca
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Received on Wed Apr 01 2026 - 11:53:07 MST