Step 7: Test the Pump

I used a jam jar with a silicone baking mat to test the final seal.

The inner cones were bolted into place then the oil was added. The assembly was placed into a shop vise and I used a propane torch to heat the bottom of the pump. In the future a stove element will be used but this was just a test..

I attached the pump to the vacuum port then ran the pump for about a 1/2 hour. I was able to get a vacuum of around 130 microns.

With no water cooling and constant heating got the vacuum down to less than 22 microns. This is far deeper than my refrigeration pump has ever gone!!! I need to water cool the pump body to get some extreme vacuums!

That is 0.022 TORR.. Let the games begin!

I will be making extensive use of this pump in the near future for some amazing instructables!
<p>Dear bro!</p><p>Diffusion pump oil is not available <br>in my country and also I can't bear the expense in importing of DP oil. <br>Here in my country side there are a lot of silicone base oil to which i <br>can use as a low vapor pressure oil, but think is I really dont know <br>which staff has to use.in this purpose. Can you do me a favor?..... If <br>you can help me out in this project of making oil for diffusion pump. <br>And also i need help in making diffusion pump.</p>
<p>Thanks for this !!!!</p>
<p>Thank you...I finally understand how a diffusion pump works. Been looking at these awhile and scratching my head. You might link to this swf with an animated cross section of how it works on a molecular level.</p><p>http://www.edwardsvacuum.com/uploadedFiles/Resource/Corporate/About_Us/diffusion_pump.swf</p>
<p><a href="http://www.edwardsvacuum.com/uploadedFiles/Resource/Corporate/About_Us/diffusion_pump.swf" rel="nofollow">http://www.edwardsvacuum.com/uploadedFiles/Resourc...</a></p>
I'm curious what sort of torch you are using? As well as the rough total amount you ended up spending? Thanks! Very cool!
The torch is a Smith Little Torch. Quite small for this job but I used what I had. <br> <br>The Stainless metal was $1 per pound at my local scrap yard &quot;Federal Metals Calgary&quot;. The retail parts were under $10 and the tubing was purchased over 10 years ago for about $20.
I'm a bit lost. Some background, a working principle and a schematic would make this a great instructable. Also, could you explain a bit more about the construction? For example in step 6, where does the copper coil come from? It's just there all of a sudden without explanation. Thanks.
Sorry about that. I got in the zone with the build. The copper tube is a gravity feed cooling apparatus. Wrap 3-4 coils of copper tube around the body of the pump. Braze this tot he body. Water is gravity fed in a steady drip to facilitate cooling of the pump body and allow the pump to cool the heated oil.
You win a follower with this pump i am making my own but i have a question can i use 2 fridge compresors in series as a mechanical pum i know that the ideal pump is the rotary vanes one, but here in Mexico they are really expensive i know that one can get a vacuum of 100mbar
Awesome project! <br><br>Surely you can aluminize using this vaccum pump, isn't?
Thanks! <br> <br>That is definitely one of the plans!
I envy you a bit... Is there something like good envy?
Yep, called &quot;admiration&quot; and &quot;inspiration&quot;.

About This Instructable




Bio: Bit of a background in various electrical and mechanical fields, obscure sense of humour and typically willing to help...
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