Neon Plant: Vacuum Pump Upgrade

[@WobblycogsUk]

Just finished this build series, very impressive work.

[@NeonPreservation]

thank you! it took a while, but i am pleased with how it turned out!

[@patriciap1214]

I am a refrigeration person I like your channel I like neon I know how to bend tubes with torches and do other things as far as your pump issue. Do you want to try to get a bigger welsh or do you want to use the right synthetic oil in it wells makes a good synthetic oil for that pump. Yo-yo is the home key to the back and the right well better the vacuum.

[@NeonPreservation]

eventually i will add a diffusion pump to the setup, which will significantly increase the pumping speed and ultimate vacuum. as per the manufacturer's recommendations, im using the oil designed for the pump, Welch DuoSeal 1407k oil.

[@ostroumovgeorgy8247]

Cool videos! Good luck with your neon workshop! Just one question: Do neon processing really need such a huge free air displacement? Tubes together with whole system looks like it have less then 1L... Isnt it ultimate pressure the most important characteristic instead of pumping speed?

[@NeonPreservation]

excellent question! you are correct that the tube does not have much volume, however when the tube is being evacuated/bombarded, the low pressure & heat causes all the impurities, water vapor, etc., to vaporize & outgas, which creates large amounts of additional volume that must be removed. the ultimate pressure of the vacuum pump *is* very important (the main reason i upgraded to the Welch pump); but the free air displacement is also very important, as there is a finite window to remove impurities from the tube while it is heated; once it starts to cool, the microscopic pores/imperfections in the glass will start to re-absorb/trap the contaminants. the higher displacement helps to remove more of the impurities before this happens. eventually i would like to add a diffusion pump to this setup. the diffusion pumps sold for the neon industry are usually rated around 600L/min, with an ultimate pressure around 0.005 microns. essentially, you want the most displacement and best ultimate pressure possible to create the cleanest tube. i hope this helps. if you're interested, i suggest reading this article about pump speeds & ultimate pressures regarding neon equipment: www.svpneon.com/VacuumPumpWork.html

[@ostroumovgeorgy8247]

@@NeonPreservation Thanks for explanation! And thanks for a link! My dream set up would be compact, probably a turbo pump, something like here: kzbin.info/www/bejne/mZSrnH6Lh6p7e6s He also have nice website on vaccum stuff! www.tubecrafter.com/

[@andrewphillip8432]

I’m trying to put together a roughly 5 gallon bucket sized vacuum chamber. Think a 1402 could pump it down to 5 micron in under an hour? I don’t have a lot of experience with this stuff unfortunately

[@NeonPreservation]

the Welch 1402 (running under ideal conditions) is rated for 160L/min of "free air displacement", which is about 42.3 gallons per minute. of course, the actual displacement is going to decrease exponentially as the chamber is evacuated, and other factors will affect that as well (e.g., temperature, vapor pressure of anything in the chamber, materials outgassing, etc.). that said, the 1402 is fantastic workhorse of a pump; it evacuates the the tubes i make to below 5 microns in just a couple of minutes. i haven't tried evacuating a volume as large as 5 gallons, but i do believe a well-functioning 1402 could do it in less than an hour. i think i need to get a large vacuum chamber and do some experiments of my own! :) good luck!

[@andrewphillip8432]

@@NeonPreservation cool that’s good to hear, I’ll probably pick one up soon. And thanks!

[@NeonPreservation]

no problem! remember to use the largest diameter possible on your vacuum tubing, fittings, etc., for maximum flow. cheers!

[@Alikhan-I12]

New tube is not emptying.