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Good Diffusion pump?

Posted: Fri Mar 09, 2018 2:29 pm
by Noah_Finlinson

Re: Good Diffusion pump?

Posted: Fri Mar 09, 2018 5:09 pm
by Rex Allers
Sorry about being a net-cop, but the heading of the group you are posting in says this,
"Do not post simple questions here. Use the New User Chat area"

Your post is very basic, that comes up with many new members, and also contains ephemeral links that don't need to be preserved long-term as they will be in the Vacuum Technology section.

Re: Good Diffusion pump?

Posted: Fri Mar 09, 2018 10:59 pm
by Jerry Biehler
First one is a 6" pump, way too big. Second should be about right. Looks to be a custom flange and you will have to make your own adapter.

Re: Good Diffusion pump?

Posted: Fri Mar 09, 2018 11:58 pm
by Noah_Finlinson
Rex Allers wrote: Fri Mar 09, 2018 5:09 pm Sorry about being a net-cop, but the heading of the group you are posting in says this,
"Do not post simple questions here. Use the New User Chat area"

Your post is very basic, that comes up with many new members, and also contains ephemeral links that don't need to be preserved long-term as they will be in the Vacuum Technology section.
No, thank you for informing me. I am still quite new to this and I was not very observant. Thanks and have a good day!

Re: Good Diffusion pump?

Posted: Sat Mar 10, 2018 3:53 am
by ian_krase
Neither of those are conflat flanges. They don't have the chunky dimensions and knife-edge. Like most diffpumps, they have plain pipe flanges, in some cases with o-ring grooves. These may be standardized or may be oddball flanges you will need to make an adapter for.

Re: Good Diffusion pump?

Posted: Fri Mar 16, 2018 10:52 pm
by prestonbarrows
Definitely not conflat flanges. Conflats have 'knife edges' with ~30 degree 'triangles' to create metal-to-metal seals. What you have shown are square profile o-ring grooves. Totally acceptable, but you will need to measure the grooves and purchase the proper o-ring to fit inside it. Diff pumps typically are o-ring sealed, no worry there.

Diff pumps are also notoriously bomb-proof. Unless there are literal bullet holes visible in the sides, you can usually safely assume they will perform well once properly cleaned, filled with the proper oil, and run at the proper conditions.

Re: Good Diffusion pump?

Posted: Sat Mar 17, 2018 2:50 pm
by ian_krase
Ehhhh, sometimes ignoramus surplus ironmongers will lose the Christmas Tree from the center and not tell anyone.

Re: Good Diffusion pump?

Posted: Sat Mar 17, 2018 9:06 pm
by John Futter
Noah

We frown on people who repeat what others have written it wastes server space
You should not have copied Rex's reply into your reply ----totally redundant

this is not Farcebook or Twotter it is a repository of good information that does not need dilution

Re: Good Diffusion pump?

Posted: Mon Mar 19, 2018 1:54 am
by Richard Hull
Thanks John. Your reminder about not copying what is in the immediate prior post is one of my pet peeves. I have posted on it often. I often wonder what drives people to do that.......

Richard Hull

Re: Good Diffusion pump?

Posted: Mon Mar 19, 2018 9:20 pm
by Adam Binns
https://www.ebay.com/itm/Varian-Air-coo ... SwjlBaMdwi if you live in the US this is a great deal as it has a throttling valve as well as being air cooled.
I'm not going to bother buying it as down under the outlet voltage is different as well as the shipping being 90 dollars.
I believe Richard hull recommends an air-cooled pump because they don't need a constant supply of water to run.

Re: Good Diffusion pump?

Posted: Tue Mar 20, 2018 10:49 am
by Richard Hull
Water cooled diff pumps are great, but only if.......

1. You have a water faucet and sink or drain nearby the fusor or are willing to construct a water line from you sink drain and faucet to the fusor, where ever it is located.

Or....

2. To avoid running up your water bill, make a full recycling water system with a suitable water pump with all lines to a bath of ice water reservoir or a small automotive heater core, (radiator with a fan) and then to a normal reservoir and back again.

I choose the zero-point-zero hassle of an air cooled diff pump.

Richard Hull