Guest barbonenet Posted March 14, 2015 Share Posted March 14, 2015 (edited) All this material need to apply Brass Acces Valve (1/4sae-1/4sae) or (1/4sae-7/16"-20) !!!! If you didn't find this valve, Drill Bit & TAP size to use, change!!!!!! What you Need 1x 2Stage Vacuum Pump (ebay) 1x TAP 7-16"-20 UNF (ebay) 2x O-Ring (better if you find O-Ring for Low Temp) 1x Loctite 243 1x Brass Acces Valve (1/4sae-1/4sae) or (1/4sae-7/16"-20) http://ph.parker.com/us/17054/en/refrigeration-access-valves/avu1f1-4 1x Drill Bit 9.5mm for Steel All this material need to apply Brass Acces Valve (1/4sae-1/4sae) or (1/4sae-7/16"-20) !!!! If you didn't find this valve, Drill Bit & TAP size to use, change!!!!!! Edited April 9, 2015 by barbonenet Quote Link to comment Share on other sites More sharing options...
Guest barbonenet Posted March 14, 2015 Share Posted March 14, 2015 (edited) First at all, search the correct Brass Access Valve....if you find Valve like post#1, you can go to next step! DEWAR CAP MOD -Remove cover cap of dewar. you can help with a screw -Now make an hole of 9,5mm with Drill, and then make thread with 7/16"-20 TAP (Attenction: Stay perpendicular and use OIL) this is a good job Ok the main work is done! -Now put on your valve Loctite 243 (here i use Teflon, but Loctite 243 it's better) ...screw up it (here i use Teflon, but Loctite 243 it's better) -change O-Ring and mount this modded Cap on Dewar (use a littlebit of grease on O-ring) put the second O-ring like me push push F I N I S H !!!!!! Edited April 9, 2015 by barbonenet Quote Link to comment Share on other sites More sharing options...
Guest barbonenet Posted March 14, 2015 Share Posted March 14, 2015 (edited) Renew Vacuum Attach 2Stage Vacuum Pump to your Dewar, and start up vacuum! Do vacuum for 30minutes..... then turnoff pump, and check vacuum after 1-2hour..... if dewar doesn't lost vacuum, turn on again Vacuum pump and remove quickly the tube from dewar!!! Turn off pump and screw up the valve caps!!!! Finish !!!! Tips: -For a better performance, warm up dewar before making vacuum!!! -If dewar lost vacuum, try to put more teflon on valve...... -if you know a Mechanic, you can ask if he can do vacuum with his Vacuum Pump (with his recharger for air conditioning). Ask here if you need help. Edited April 9, 2015 by barbonenet Quote Link to comment Share on other sites More sharing options...
Sergio73 Posted March 14, 2015 Share Posted March 14, 2015 WOW!!!! Nice work !!! Quote Link to comment Share on other sites More sharing options...
Guest barbonenet Posted March 14, 2015 Share Posted March 14, 2015 (edited) Thanks Edited March 14, 2015 by barbonenet Quote Link to comment Share on other sites More sharing options...
DrWeez Posted March 14, 2015 Share Posted March 14, 2015 Thanks, great info Quote Link to comment Share on other sites More sharing options...
der8auer Posted March 14, 2015 Share Posted March 14, 2015 Amazing stuff. Great work! Quote Link to comment Share on other sites More sharing options...
dinos22 Posted March 14, 2015 Share Posted March 14, 2015 awesome stuff man Quote Link to comment Share on other sites More sharing options...
nachtfalke Posted March 15, 2015 Share Posted March 15, 2015 nice work!! i recomanded to change teflon with threadlocker LOCTITE 243( medium strenght) Quote Link to comment Share on other sites More sharing options...
ogblaz Posted March 15, 2015 Share Posted March 15, 2015 Hi, great guide my friend, I did this a week ago and my dewars now evap rate is much better than before, I lost 10L in three days now its less than a liter per day. Its bad, but I think this is normal for my type of dewar. I took the plug out of the dewar, the vaccum was present but was bad, then i go and bought the 1\4 valve like you told me, took the plug and the valve to a guy with the mill and he made threads on the plug and the valve, i used locktite "rope", bought a new oring, and used silicone grease on the plug. In original is high vaccum grease, but its 30€ i dont think it makes much diference. Thanks again for all your help! Quote Link to comment Share on other sites More sharing options...
Guest barbonenet Posted March 15, 2015 Share Posted March 15, 2015 Nice suggestion locktite.....i didn't think to it i'll add it . After you apply this valve.....you can search if there is a little hole in your dewar....instead make vacuum, put inside air to 1-1,5bar and search the hole with soap.... Sorry guys it's too tecnic for my poor english;) Quote Link to comment Share on other sites More sharing options...
Crew Vivi Posted March 26, 2015 Crew Share Posted March 26, 2015 this is awesome thanks for the tips!! Quote Link to comment Share on other sites More sharing options...
ogblaz Posted April 7, 2015 Share Posted April 7, 2015 Its a shame that already the pictures are gone, somebody should put them to a more reliable server. Quote Link to comment Share on other sites More sharing options...
Guest barbonenet Posted April 7, 2015 Share Posted April 7, 2015 I put on another server. .....dropbox is not the best for share images...... Quote Link to comment Share on other sites More sharing options...
Guest barbonenet Posted April 9, 2015 Share Posted April 9, 2015 all picture are on......i puted image on altervista space...... Quote Link to comment Share on other sites More sharing options...
subaruwrc Posted April 19, 2015 Share Posted April 19, 2015 I should try this with my old dewar .. Quote Link to comment Share on other sites More sharing options...
Guest barbonenet Posted April 20, 2015 Share Posted April 20, 2015 I should try this with my old dewar .. Let we know Quote Link to comment Share on other sites More sharing options...
d0minat0r Posted September 7, 2015 Share Posted September 7, 2015 I need to do this on my dewar, lose 20l Ln2 for night Quote Link to comment Share on other sites More sharing options...
Guest barbonenet Posted September 7, 2015 Share Posted September 7, 2015 After that, your dewar will be as new;) Quote Link to comment Share on other sites More sharing options...
d0minat0r Posted September 8, 2015 Share Posted September 8, 2015 I need to make new round brass part.Can not pull out old part. Quote Link to comment Share on other sites More sharing options...
d0minat0r Posted September 8, 2015 Share Posted September 8, 2015 I still have some options in mind. I'll think more what I'm doing. All suggestions are welcome Quote Link to comment Share on other sites More sharing options...
ogblaz Posted September 8, 2015 Share Posted September 8, 2015 Just take to a shop so they drill thru the whole brass piece, make a thread and screw in the valve. Check the seals on the whole thing and you should be ready to vacuum the thing. Quote Link to comment Share on other sites More sharing options...
Guest barbonenet Posted September 8, 2015 Share Posted September 8, 2015 Just take to a shop so they drill thru the whole brass piece, make a thread and screw in the valve. Check the seals on the whole thing and you should be ready to vacuum the thing. yeah exactly. maybe the thread is perfect on the brass piece.....check if you can find a valve 1/4SAE for this thread. So, if you find a right valve for that thread, you have only to make an hole on the other side! Quote Link to comment Share on other sites More sharing options...
techjesse Posted September 13, 2015 Share Posted September 13, 2015 My Sponsored Taylor-Wharton 32L Liquid Nitrogen Dewar PGT Testing hold time in 90f temp to see if I need to use this excellent procedure. A special thanks to barbonenet Quote Link to comment Share on other sites More sharing options...
Guest barbonenet Posted September 14, 2015 Share Posted September 14, 2015 you' re welcome Quote Link to comment Share on other sites More sharing options...
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