Search found 452 matches

by ian_krase
Wed Feb 08, 2017 5:20 am
Forum: New User Chat Area
Topic: Diffusion Pump Design Text?
Replies: 7
Views: 1481

Re: Diffusion Pump Design Text?

Cool, thank you.

Looks like I'll probably need to go to the university library for that book. Another for the list, I guess.
by ian_krase
Fri Feb 03, 2017 6:07 am
Forum: New User Chat Area
Topic: Diffusion Pump Design Text?
Replies: 7
Views: 1481

Re: Diffusion Pump Design Text?

I guess so, kinda. It also matters that I'm trying to keep my system *extremely* small and lightweight (and able to be backed by a mech pump that is also small and lightweight). Really small diff pumps are not as common.
by ian_krase
Thu Feb 02, 2017 8:54 am
Forum: New User Chat Area
Topic: Diffusion Pump Design Text?
Replies: 7
Views: 1481

Re: Diffusion Pump Design Text?

One of the homebuilt diff pumps I saw was running with silicone oil made by vacuum evaporating the lighter fractions from some kind of silicone lubricant. I'm thinking that with my sub-2-inch design, I should be able to use one of the tiny 100 ml bottles. Sadly, I don't have access to sophisticated ...
by ian_krase
Thu Feb 02, 2017 8:02 am
Forum: New User Chat Area
Topic: Diffusion Pump Design Text?
Replies: 7
Views: 1481

Diffusion Pump Design Text?

Does anybody have any tips on designing diffusion pumps, or suggestions of texts on how to design them? Strong's Procedures in Experimental Physics has a bewildering variety of illustrations of strange diffusion pump designs -- some inside-out or upside down, some with multiple rocket-engine-style d...
by ian_krase
Sun Jan 29, 2017 7:37 am
Forum: New User Chat Area
Topic: Pneumatic Valve Into Manual Valve?
Replies: 2
Views: 455

Re: Pneumatic Valve Into Manual Valve?

I was afraid of that.

With a bit more searching (and creative use of search terms) I found a good deal on a KF16 manual valve. I still need to find a KF25 one.
by ian_krase
Fri Jan 27, 2017 5:15 am
Forum: New User Chat Area
Topic: Pneumatic Valve Into Manual Valve?
Replies: 2
Views: 455

Pneumatic Valve Into Manual Valve?

Pneumatic vacuum valves are pretty common at a very good price on Ebay, with the corresponding manual valves (having pretty similar design) being... less common. I do not have the space or facilities to provide compressed air for pneumatic valves. So, I'm curious whether the way these things are put...
by ian_krase
Fri Jan 27, 2017 4:53 am
Forum: New User Chat Area
Topic: Bolts for vacuum chambers
Replies: 12
Views: 1597

Re: Bolts for vacuum chambers

I'm curious why plain high-grade carbon steel bolts are not used for atmosphere-side bolting. Minute contamination? Rust transfer to stainless?
by ian_krase
Sun Jan 22, 2017 4:30 am
Forum: New User Chat Area
Topic: What is this device?
Replies: 6
Views: 951

Re: What is this device?

IIRC aviation (military aviation? Aviation in general?) has lots of really unusual AC power delivery specifications.
by ian_krase
Wed Jan 18, 2017 9:39 am
Forum: New User Chat Area
Topic: What HV pumps can I rough with the mech pump I have?
Replies: 22
Views: 2684

Re: What HV pumps can I rough with the mech pump I have?

Yeah. I'm not sure what to do though, last time I tried turning off the pump on an evacuated chamber with no isolation valve did not go well. Do I just need to get a real vacuum valve?
by ian_krase
Tue Jan 17, 2017 6:35 am
Forum: New User Chat Area
Topic: What HV pumps can I rough with the mech pump I have?
Replies: 22
Views: 2684

Re: What HV pumps can I rough with the mech pump I have?

Well, today I tried it...

Got to 300 microns, which isn't great but which is much better.

How hot is it normal for a pump to get?

Just moving the valve causes a jump from 300 um to 600 um, and then the pressure rises about 150 um in 30 seconds which doesn't sound too good.