Here’s some more info from local tame engineers
Hi Gary
I trust all is good with you !!
Could you kindly post this on the mailing list for me.
Cheers
Andy
This is my understanding.
A very long time ago, a lab technician in Europe made a huge mistake.
This caused the nitrogen vessel to become completely blocked with a
large amount of solid ice.
After a few days the nitrogen vessel ruptured and released a huge amount
of high pressure gas.
The small release valve on the vacuum valve could not cope with this
large amount of pressure, and the upper part of the cryostat ruptured
and hit the ceiling !!!!
After this Oxford supplied the retro fit kits, they were used like this.
Once the magnet was installed, these ' extended retro fit bolts were
fitted and NOT tightened down, leaving a gap of a about 1/4 inches, so
that if this ever happened again, the top half of the magnet would lift
up and the gas could release from the two halves.
On the very old 500's, with a round base, they supplied additional leg
clamps as well.
Kind regards
Andy Hield
Quench Cryogenics Limited
Email; andy.hield_at_quenchcryogenics.co.uk<mailto:andy.hield_at_quenchcryogenics.co.uk>
Hi Gary
I personally carried out numerous retrofits and as Andy Heild has stated the
reason behind the need for the action taken.
The retrofit itself consisted of removing the bolts around the OVC flange and
replacing them with new bolts and a thick foam washer that would allow the
OVC to move on the bolts compressing the rubber washer.
This would allow the pressure to be released and thus prevent the scenario =
that Andy described.
Kind regards.
Paul
Dr Gary S Thompson NMR Facility Manager
CCPN CoI & Working Group Member
Wellcome Trust Biomolecular NMR Facility
School of Biosciences, Division of Natural Sciences
University of Kent, Canterbury, Kent, England, CT2 7NZ
☎:01227 82 7117
✉️: g.s.thompson_at_kent.ac.uk
orchid: orcid.org/0000-0001-9399-7636
On 15 Aug 2024, at 14:46, Wendy Breyer <web216_at_lehigh.edu> wrote:
Hi,
Gary's recollection is correct - since my last post, I learned that the retrofit
bolts are supposed to allow the bottom part of the magnet to separate a small o
distance from the top in the event of overpressure... and my cryoprobe should
be OK even if the magnet quenches (fingers-crossed).
Thanks,
Wendy
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#1508): https://urldefense.com/v3/__https://ammrl.groups=
.io/g/main/message/1508__;!!PvDODwlR4mBZyAb0!WhgIZExJxHSnueO55E51gwpeF-8Pvc=
Ofc9kU6PGQ4zEsVFAUg9y5gWWayD8RcET0E9yVEuocskbJd_AlZnn_FPO8vqzU$
Mute This Topic: https://urldefense.com/v3/__https://groups.io/mt/107818605=
/7559972__;!!PvDODwlR4mBZyAb0!WhgIZExJxHSnueO55E51gwpeF-8PvcOfc9kU6PGQ4zEsV=
FAUg9y5gWWayD8RcET0E9yVEuocskbJd_AlZnn_FPwXg3bT$
Mute #bruker:
https://urldefense.com/v3/__https://ammrl.groups.io/g/main/mut=
ehashtag/bruker__;!!PvDODwlR4mBZyAb0!WhgIZExJxHSnueO55E51gwpeF-8PvcOfc9kU6P=
GQ4zEsVFAUg9y5gWWayD8RcET0E9yVEuocskbJd_AlZnn_FCiB3mt2$
Mute #hardware:
https://urldefense.com/v3/__https://ammrl.groups.io/g/main/m=
utehashtag/hardware__;!!PvDODwlR4mBZyAb0!WhgIZExJxHSnueO55E51gwpeF-8PvcOfc9=
kU6PGQ4zEsVFAUg9y5gWWayD8RcET0E9yVEuocskbJd_AlZnn_FBepGxKS$
Group Owner: main+owner_at_ammrl.groups.io
-=-=-=-=-=-=-=-=-=-=-=-
Received on Thu Aug 15 2024 - 09:34:19 MST