Could you help me judge this vacuum pump?

Every fusor and fusion system seems to need a vacuum. This area is for detailed discussion of vacuum systems, materials, gauging, etc. related to fusor or fusion research.
Martin Shahi
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Could you help me judge this vacuum pump?

Post by Martin Shahi » Thu Aug 29, 2013 4:11 pm

Hi everyone! I have found this vacuum pump here: http://www.ebay.co.uk/itm/ALCATEL-2008A ... 4ac702930b
and I would very much like to know what you think of it. Refurbished it should have the following specifications:
7CFM
1X10-4 torr ultimate pressure

I'm hoping to build a full fusor reactor and I would like to know if this would fit the bill with a diffusion pump as well (which I have yet to find so any help in that
area is greatly appreciated too).
Thanks!

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Nick Peskosky
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Re: Could you help me judge this vacuum pump?

Post by Nick Peskosky » Thu Aug 29, 2013 4:32 pm

Martin,

The Alcatel 20XX series pumps are terrific backing pumps (I personally own an Alcatel 2021i) and if the pump listed in the auction runs in an even halfway decent manner you should be more than off to the races in pulling a vacuum. The inlet/outlet seem to be covered in dirty grease and the pump's exterior is a little worse for the wear but none of these cosmetic issues will ultimately impact the serviceability of the pump. My advice would be to message the seller and ensure that the pump was in the functional condition prior to having its high-vac oil drained. I word of caution, 400$ is a pretty hefty price tag for a pump in this condition especially considering the seller is charging for shipping. Even though high vacuum equipment is scarce across the pond I'd recommend you keep your eyes peeled and wait for a while until you see a pump come along in the 100-200$ price range. Lastly, refurbishing is likely not needed for Fusor applications unless the pump has a broken vane/ruptured gasket in which case you should probably search for another pump anyway. Numerous threads on this forum discuss disassembling/cleaning these pumps as well as flushing the pumps with oil in order to return them to the mTorr pumping range suitable for backing a typical diffusion pump or TMP.
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Martin Shahi
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Re: Could you help me judge this vacuum pump?

Post by Martin Shahi » Thu Aug 29, 2013 4:41 pm

Thank you very much for your advice! I shall ask the seller about the pump's functionality and I will try and negotiate the price down. Any advice regarding good diffusion pumps?

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Chris Bradley
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Re: Could you help me judge this vacuum pump?

Post by Chris Bradley » Thu Aug 29, 2013 4:53 pm

Guilty!

Martin Shahi
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Re: Could you help me judge this vacuum pump?

Post by Martin Shahi » Thu Aug 29, 2013 4:55 pm

Guilty? I'm sorry I don't understand.

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Richard Hull
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Re: Could you help me judge this vacuum pump?

Post by Richard Hull » Thu Aug 29, 2013 5:07 pm

Here is where a small use of the quotes or a single, self generated, sentence referencing the quilty plea might have helped. We get either a flood or a drought.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

Martin Shahi
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Re: Could you help me judge this vacuum pump?

Post by Martin Shahi » Thu Aug 29, 2013 8:22 pm

Richard Hull wrote:Here is where a small use of the quotes or a single, self generated, sentence referencing the quilty plea might have helped. We get either a flood or a drought.

Richard Hull
Like this? Also do you have any advice regarding a good diffusion pump?

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Richard Hull
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Re: Could you help me judge this vacuum pump?

Post by Richard Hull » Thu Aug 29, 2013 8:36 pm

I was speaking to Chris Bradley's failure to clarify. "Guilty"

Regarding advice on selecting a good diffusion pump.....No. I have no advice at all... other than that which I gave in the long FAQs I wrote a while back on diffusion pump selection, cleaning and use!!!
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

Martin Shahi
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Joined: Thu Aug 29, 2013 1:06 pm
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Re: Could you help me judge this vacuum pump?

Post by Martin Shahi » Fri Aug 30, 2013 8:03 am

Richard Hull wrote:I was speaking to Chris Bradley's failure to clarify. "Guilty"

Regarding advice on selecting a good diffusion pump.....No. I have no advice at all... other than that which I gave in the long FAQs I wrote a while back on diffusion pump selection, cleaning and use!!!
I read this FAQ but unless I am mistaken I didn't see any brand recommendations in it like you wrote in you FAQ regarding mechanical pumps.

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Richard Hull
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Re: Could you help me judge this vacuum pump?

Post by Richard Hull » Fri Aug 30, 2013 2:48 pm

Brands?! What does that have to do with anything? If it is a diffusion pump and the heater works, it's OK.

As noted in my FAQ, select an air cooled unit with a 2 to 4 inch throat. Big Belly Bob's diff pump is as good as the finest Varian. They are like just tubes with a heater and a jet stack dropped in them. Zero moving parts.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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