Search found 24 matches

by Jeremy Adams
Wed Jul 11, 2018 9:51 pm
Forum: Vacuum Technology (& FAQs)
Topic: Tips on Roughing Pressure
Replies: 2
Views: 1888

Re: Tips on Roughing Pressure

The manual is vague and says that a 'High Vacuum Pump Oil' is required but does not specify a brand or type. I can try to get in contact with someone who knows about this oil but it's unlikely they will confirm it works for my pump specifically (which is why I posted here to see if you guys know mor...
by Jeremy Adams
Wed Jul 11, 2018 6:25 pm
Forum: Vacuum Technology (& FAQs)
Topic: Tips on Roughing Pressure
Replies: 2
Views: 1888

Tips on Roughing Pressure

It turns out my dual stage 12 CFM roughing pump is only reaching 40 microns at its lowest. I would prefer it to reach at least 15 microns for roughing my diffusion pump. It is only about one year old and doesn't have much wear so it should be capable of achieving close to its rated ultimate pressure...
by Jeremy Adams
Sat Jun 30, 2018 7:32 pm
Forum: Vacuum Technology (& FAQs)
Topic: Back-Streaming Diffusion Oil
Replies: 10
Views: 4697

Re: Back-Streaming Diffusion Oil

I am using ECO-704 Silicone Diffusion pump oil (which is an improved formula of DC-704). This fluid is pretty viscous but I should probably have a baffle on my diffusion pump exhaust just in case there is any back flow.
by Jeremy Adams
Fri Jun 29, 2018 4:59 pm
Forum: Vacuum Technology (& FAQs)
Topic: Back-Streaming Diffusion Oil
Replies: 10
Views: 4697

Re: Back-Streaming Diffusion Oil

Oil was being sucked out from the diff pump exhaust hole (the diffusion pump outlet) which was connected to the roughing pump. Perhaps we need a forline exhaust baffle? The pressure of the roughing pump was about 7x10^-2 torr at its lowest.
by Jeremy Adams
Fri Jun 29, 2018 4:44 pm
Forum: Vacuum Technology (& FAQs)
Topic: Back-Streaming Diffusion Oil
Replies: 10
Views: 4697

Re: Back-Streaming Diffusion Oil

The roughing pump is not connected to the diffusion pump in the picture above because it was taken after I disconnected the bellows and noticed oil flowing backwards to the roughing pump. Also aluminum at the top of the diffusion pump is around a blank flange, just there to keep it clean. The diffus...
by Jeremy Adams
Fri Jun 29, 2018 3:09 am
Forum: Vacuum Technology (& FAQs)
Topic: Back-Streaming Diffusion Oil
Replies: 10
Views: 4697

Back-Streaming Diffusion Oil

Hello, Today I was running my pumping system - a 2 stage roughing pump connected to an oil diffusion pump when I found that my roughing pump was actually pulling oil out of the diffusion pump through a bellows connecting them. The bellows was dripping in diffusion pump oil on its connecting end to t...
by Jeremy Adams
Thu Jul 13, 2017 2:27 am
Forum: Vacuum Technology (& FAQs)
Topic: Vacuum System Not Performing. Why?
Replies: 3
Views: 1601

Vacuum System Not Performing. Why?

Hi Everyone, Today I did a vacuum test and switched on the hot cathode gauge about 55 minutes in to running the system (ample time for the diffusion pump to warm up and pump down a small space where the gauge was attached). As soon as the filament flicked on it started releasing gas into the glass w...
by Jeremy Adams
Tue Jan 03, 2017 2:45 am
Forum: Vacuum Technology (& FAQs)
Topic: Pressure Gauge Problems
Replies: 6
Views: 2912

Re: Pressure Gauge Problems

Thank you for the advice, I was confused on where to connect the roughing pump and connected it to the "rough port" instead of where it should've been connected. The pictures of the pressure gauge were taken while it was turned off. It was running at to high of a pressure because of my incorrect rou...
by Jeremy Adams
Mon Jan 02, 2017 3:13 pm
Forum: Vacuum Technology (& FAQs)
Topic: Pressure Gauge Problems
Replies: 6
Views: 2912

Pressure Gauge Problems

Happy New Years Everyone! So today I gave my vacuum system a run to see what pressure I could get out of it. It is an oil diffusion pump (a reliable edwards diffstack model 63) and roughing pump. They are both in great condition and the roughing pump has been consistently working properly. The diffu...
by Jeremy Adams
Tue Oct 04, 2016 1:36 pm
Forum: Vacuum Technology (& FAQs)
Topic: Turbo pump grease
Replies: 5
Views: 2624

Re: Turbo pump grease

Thanks for the info. I contacted Kryox and also found some greases in the links below. I get that the grease might not work in our pump, but trying something to get our pump to work is better than not. http://store.tmcindustries.com/CHRISTO-LUBE-MCG-109-Grease-2-oz-Syringe_p_405.html http://store.tm...