For those interested, I've compiled the email response I've received
concerning the move of our 300 MHz Mercury-Vx. Sorry for the length, but
I did get quite a few responses; I've removed full names and locations
(I do not feel comfortable publishing these) and only included responses
which did not specify "confidential" by any means.
Thanks again to the community for the numerous responses,
Axel
-----------------------------------
Here is my original post:
AMMRL'ers,
There has been talk of a move for our 300MHz Mercury-Vx to a near by
location (on the same floor). I've looked over the archive and found
many tips on moving an NMR instrument but my real concern is the
post-move difficulties not mentioned. Frankly, this instrument has been
in its current location many years before my arrival and is working fine
(routine synthetic chemistry applications) with a minimal amount of
maintenance.
My questions for those of you who have moved a comparable instrument:
1) Were there some unexpected changes in the
performance/maintenance of the instrument after the move?
2) What are the potential troubles associated with the move alone
(failing o-rings? Dewar damage? Quenching?)
3) How much down time do you evaluate the move to have taken
(until the instrument was fully operational as before the move)?
4) Was it worth it? Did you evaluate the cost of the move (done by
yourself and/or done by certified Varian employees)?
There have to be horror stories which are not mentioned in the archives
.. I'm really interested in those too!
The current location is in a corner of an analytical lab and the move
could be to a small central room surrounded by three hall ways. To place
everything, the spectroscopist would practically have to sit in the 5
gauss field - should I be concerned by this? Anyhow, I'm of the opinion
that high-tech instruments such as NMRs should not be moved unless the
moon is crashing down to earth :-) Am I alone?
I've also looked over the minimal room size (8x10 feet can you believe
it?) for this instrument and the recommended room layouts by Varian -
practically though, what would be the minimal room size that you the
users recommend? The radial 5 gauss line is at about 6 feet ...
Axel
-------------------------------
I think such a move can be done cheaply, depending on what kinds of
doors you are going through. I have moved 300 and 200 MHz NMR's on the
same floor without discharging the magnets (this is the main cost of the
move). We also moved a 200 widebore and a 300 between floors charged. I
guess what I would say is that if the doors are wide enough and high
enough, and the floor is smooth, I wouldn't think twice about moving the
magnet charged - it might even be worth taking the moldings off the
doors if they need to be widened. I haven't had a magnet problem result
from such a move, although lots of problems are theoretically possible.
Regarding the room size, that is small, but it might be OK depending on
what is in the walls. I am sure you will hear from others of instruments
in such small rooms. I have had magnets within 2 feet of a wall and had
few shimming problems.
We've moved a few spectrometers ourselves, and have not experienced any
significant problems associated with the moves. We've even moved 300s
on temporary basis to get them out of the way of remodeling work.
There's no doubt that many things can go wrong, but obviously in our
case, all went ok.
If you are moving the 300 on the same floor, it's even possible to move
the magnet at-field. I would recommend you have a professional do this
(especially if you have to get through some doorways). Some maintenance
may be needed on your magnet soon (somewhere between 12 and 18 yrs is
typical for a supercon needing new o-rings), so perhaps this would be a
good time to do that. If the magnet is not that old (a Mercury cannot
be), then do not do this.
The space is small, but can be workable. We have a Mercury 300 in an
only slightly larger space, 10x12, and it has an SMS sample changer with
it in that room. The user almost sits in the doorway, but others can
get past to get to the sample changer.
I don't suppose any of this is necessarily what you were hoping to hear,
but perhaps it will help alleviate undue concerns. A move of a 300
should (hopefully) not be a major issue. I would wholeheartedly agree,
even so, that a move of an NMR spectrometer should not be done unless
absolutely necessary.
We moved a Varian 300 MHz last year and really it all went smoothly. We
moved it live. The fringe field on a 300 narrow bore just isn't that
much and we took reasonable care. We moved it up one floor (using the
freight
elevator) and along a couple hallways, maybe 50+ yards total.
1) the instrument worked fine after the move. Some adjustment (not
much) in the RT shims was required. Re-cryoshimming wasn't necessary.
The boil-off rates were unchanged within about a day after the move.
2) There is a danger of quench of course so be careful - analyze your
"move route" and the doorways you must pass thru. Top off the LHe before
and afte r the move. We have an all aluminum "dolly" that we built a
few years ago for moving magnets. We lifted the magnet onto the dolly
and away we went.
The console can be moved quite easily.
3) We had three days downtime although I think you can do it quicker.
We did one day to get it ready to move, moving day, and a day to
reassemble and shim etc. I think you could get it all done in one long
day if you hustled.
4) Moving it ourselves was definetly worth it. Varian wanted $10K to do
it!
We did it ourselves for $0, though I admit we had all the gear on hand
to move it ourselves.
The move was really not that bad - its all the worrying beforehand
that's the bad part.
I've move a 200 & a 400 each twice at field. We got away with it each
time. The 200 (a Varian R2D2) took less than an hour to shim to spec
after the move, and was in a room of about 8x8. (The 400 somewhat
longer.) Your experience may differ (a lot, or a little) but you may be
able to get away with a lot.
1. No.
2. None for those moves.
3. In those cases, it was a matter of room prep more than anything.
4. Absolutely worth it. No cost analysis necessary - down time was
less than two days per instrument.
Again, your experience may vary. But you might be amazed what these
magnets can do.
I do not have experience with moving a magnet, but I just want to point
out one major concern with sitting an NMR magnet in such a small room.
Air quality and safety are a big concern with the constant boil off of
liquid nitrogen and helium. Be sure that the small room in question has
adequate ventilation, possibly with an emergency venting system (in case
of a magnet quench). An Oxygen monitor/detector would also be
necessary.
In 1995, we moved a GE QE-300 live down 2 floors and down 2 long halls.
The instrument was fine before and after. No horror stories for that
instrument move. Around the same time, [name removed] moved a 10 year
old system and changed o-rings. It lasted 5 more years. There were
some horror stories with that system, due to circumstances unrelated to
the move.
Hope this helps,
About 3 years ago we moved our entire company 25 miles north. At that
time I had a Mercury 400 on site. We also owned a Mercury 300 that was
in CA that we were moving to Delaware. In addition I had purchased an
Inova 500 that needed to be set up.
We changed the seals on all the magnets that we moved, which is almost
always done. The systems all performed up to spec after the move. It
took us about 3 weeks by the time we de-energized the magnet, warmed it
up, crated and transported it, changed the seals, pumped down the vacuum
and re-energized and then re-shimmed and met specs. So...there was no
degradation of performance after the move.
I would not recommend moving the magnet energized. I have seen that
done but the potential for damage to the magnet is significant. You
might end up quenching anyway and the seals really should be changed
during a move. It takes a bit more time to blow out all the cryogens and
warm the magnet up but it's worth it.
I would really, REALLY recommend getting Varian to handle the move for
you. You will need to find riggers yourself. When we were [name
removed] we gave one of our systems to a university. It was an Inova
300 with one of the original Varian magnets with the Indium seals. They
hired a small outfit to set the system back up. The people who were
hired had only worked for Bruker and knew nothing about Induim seals.
The seals weren't changed and the end of a rather lengthy story is that
the magnet was trashed. Varian will be more expensive but at the end,
your system will meet spec. I believe that they will do a site survey
for you as part of the price to tell you whether your room is big
enough.
I agree with you about not moving high tech equipment but there is at
least one place that I know of where they move magnets around routinely
with no serious consequences (except financial).
But if the moon is crashing down to Earth, I think we have other, more
serious problems to worry about than our dear NMR spectrometers... ; - )
Which is also why I think (here in California) that strapping NMR magnet
to ceiling beams etc. is missing the mark, because, again, if we have a
tremor or quake of any significant strength, I will not worry too much
about 'my' 4 spectrometers, but much more about my family. Other than
that, yes, I certainly do agree with you that NMR spectrometers should
be placed in a proper locale, not to moved for the foreseeable future.
We have a 400 Mercury VX (incl. SMS 50) in a second floor setting (a
triangular shaped room with sun-lit windows on the hypotenuse!) where
the magnet was located, close to the windows(!), at about the half-way
mark of the hypotenuse (situated before I was hired...). When we needed
to accommodate a new spectrometer in this same room (again, not by my
choice) we did have Thuan Truong, a Varian service engineer help us move
it live. We moved it only ~8-10 feet by sliding a dozen, or so, steel
rods long enough to extend under the frame the magnet sits in. I don't
know if your 300 has the same frame (see attached picture) as our 400.
But it CAN be done with an energized magnet and without any serious
side-effects. I think we had contract drawn up with Varian, but I do
not recall how it was phrased or what the dollar amount was - but I
think we paid Thuan and Varian by the hour. Granted it was a VERY short
distance (how far would you have to go?) and we got done in less than a
day, including Thuan shimming it back up to meet specs. A very pleasant
experience, though.
I have experience moving two complete NMR systems (a Varian Gemini 300
and a Bruker AC 250), both at field. The Varian was one of the old style
"quench-o-matic" R2D2 models and the other was a more conventional
Oxford style magnet. Both of these moves took place while I was working
in the Chemistry Department and were a little more involved than simply
moving the instrument to another room on the same floor. The magnets and
consoles were both moved from the sub-basement to the fourth floor.
These moves involved two elevator rides as well as a "sloped"
breeze-way.
We first moved the consoles to their new homes as that was the easy
part. We then filled the magnets with helium and nitrogen the day before
the move (our assumption was that the magnet would be more "stable" when
full). We then lifted the magnet with an engine hoist (yes it was steel)
and nylon straps. An aluminum tripod would probably be a better choice.
The legs were removed and the magnet gently placed on a wooden cart
(basically a skateboard on steroids). We the pushed the magnet as
delicately as we could to it's new location. Both moves went without a
hitch. The time required for each move was less than a day. We were
taking spectra before we went home.
To directly answer your questions:
1) We saw no unexpected degradation to the spectral quality.
2) The biggest potential problem was a quench. We figured if it did
quench, we would just re-energize the magnet in it's new location.
3) As I said, we were able to do the entire move(s) over the course of a
couple days.
4) Absolutely. The move was 100% free.
If you have any questions, please feel free to contact me.
All of the bad things you list have some probability of occurring. We
have moved systems like this several times without major problems.
However, if you are not accustomed to doing this sort of thing, what
seemed minor problems to us might be major problems for you. I would
recommend having it moved by someone with experience, but that doesn't
have to be Varian. I would get some quotes from third party vendors. Be
sure you know the terms. For example, will they reenergize the system
if it quenches or if the helium consumption doesn't return to normal
after the move?
Another consideration is the five gauss field. We generally insist on
keeping the five gauss envelope out of public areas. It sounds like this
would not be the case in your proposed new location.
1) No
2) Depends on how you move it. This is a relatively small magnet so you
can probably move it live. You have to clear the path and make sure
nothing magnetic is around. In our case, the door frames were magnetic
and we made sure it went through the center so that any tug was
symmetric. HOWEVER, we chose to move it live because we didn't have the
leads to bring is down. The further you have to move it the more
strongly I would recommend that you bring it down, move it, and ramp it
back up. I will be putting a 300 wide bore on an elevator in a few
months and that one I will bring the field down and move cold.
3) If you move live, a couple of days. If you bring it down move and
ramp back up, a week. You have to wait for it to settle down and cryo
shim.
4) We felt the cost for Varian to move it was prohibitive given small
academic budgets and excellent support staff who could do it. We
wouldn't have even called Varian except that we didn't have the leads.
They should not be moved with out good reason. The higher the field, the
better the reason had better be. The chemistry department here is
undergoing extensive renovations so whole laboratories are moving.
Are you going to move the magnet energised or not? To answer that,
you'll need to study the width and height of each doorway or passage
between other instruments, gaps or bumps in the floor between locations,
and what moving equipment is available. Floor imperfections are not
critical, but you should be aware of where you'll need to lift or go
slow. A 2" gap at an elevator door should be bridged; thresholds can be
lifted over. I assume it has either an R2D2 Varian magnet or the AlOx
Oxford magnet. Either is light enough to easily lift by hand with 2-4
guys. Slide two 6' pieces of 1X4 lumber under the legs for handles, set
it on a low wooden furniture dolly, and away you go! Turn or remove the
stacks to make it shorter. I do NOT recommend trying to pass an
energised magnet through a single-wide steel door. A steel double-door
is OK, but you need to tie back the doors and keep the magnet centered
in the passage. Wooden doors should be OK, but check the frame also.
If the magnetic environment through the entire move is not hazardous,
then I'd move it energised.
If energised, you must top up the LHe in the magnet, and remove all LN2
from the magnet before lifting. Replace the LN2 after the move. The
magnet will likely require cryoshimming in the new location, even if you
move it energised. You'll need a shim power supply and the magnet
energisation stick to do that. If you aren't able to cryoshim it
yourself, I can recommend Triangle Analytical to do it (they're also
capable of the entire move and setup). Triangle is headquartered in
Cary, NC.
http://www.triangleanalytical.com/index.htm
If you run down the field, of course you'll need a magnet power supply
to re-energise. With no field, the LHe level is not so important, but
you should still empty the LN2 from the magnet, then replace it after
the move (this reduces the suspended mass in the magnet dewar, reducing
the possibilty of internal breakage). If you don't refill all cryogens
immediately after the move, the magnet temperature will begin to rise,
necessitating additional cryogens and time to recool it.
Another issue is the console. Be sure to mark in you own hand
everything you disconnect, because the cables sometimes get switched
over the years. Assuming you don't have a cryoshim or magnet power
supply, the cheapest move would be to do the actual move yourself, and
then hire Triangle to come in and re-energise the magnet and cryoshim it
to spec. However, if time is a concern I would hire Triangle to do the
whole shebang.
BTW, computers, consoles and other electronics work OK in fields
exceeding 50G. About 50-100G is the maximum field for the console, due
to the fans. The magnet leg box contains solenoid valves and preamps
with no problems. The host computer could be in another room, because
the only connection to the console is the internet cable.
Total time without spectra, with the magnet moved de-energised, but
cold:
Day 1, de-energise the magnet, disconnect and move the console and host,
remove LN2 from magnet and move magnet.
Day2, refill cryogens, set up console and host, re-energise, possibly
cryoshim.
Day 3, cryoshim, RT shim, possibly begin specs.
Day 4, RT shim, meet specs.
This might be a typical field engineer's schedule with unlimited access.
If access is limited to business hours, the work could take up to twice
as long. I'd expect quotes for the work to be in the $10,000 ballpark.
[...] I've moved, installed, or repaired ~100 magnets.
Received on Mon Sep 11 2006 - 13:37:00 MST