Nitrogen purging

[teyber]

hello!

just getting together birthday and christmas stuff. Got lathe, thermometer, brake, et cetera ordered but i still need to handle nitrogen. This is like killermiller's thread, however in a earlier stage :D

So i am thinking a 20 cuft cylinder of industrial grade nitrogen. I think that sounds about right? Today is sunday and i cannot get ahold of airgas, the price of that shouldn't be more then 50-75$ correct?(not including nitrogen itself). I now am looking for a regulator and have no idea what to look for. this is a possibilitly. Will the 580 inlet fit on our types of nitrogen tanks? do i want a higher quality one then that? How much more is it for one with a flow meter?(i cannot find one with flowmeter...:shakes: ) but the most important question is how do i connect the nitrogen with the different size tubing? like how do i get from the regulator to the 1/4" tubing or say regulator to the 3/8" tubing?

thanks so much. i appreciate all of your help.

Reed

[teyber]

edit: sorry hyperlink didn't work. Here was the one i was talking about:
http://cgi.ebay.com/New-Hobart-Union-Carbide-Inert-Gas-Regulator-CGA-580_W0QQitemZ320174306617QQihZ011QQcategoryZ26237Q QrdZ1QQssPageNameZWD1VQQcmdZViewItem

[killermiller]

There is coupler that goes from the nitrogen cylinder to a standard npt thread. Mine goes to 1/2. Any inert regultor will work. You can find them on ebay for 15 bucks or so.

someone should confirm but this will work
link (http://cgi.ebay.com/ARGON-REGULATOR_W0QQitemZ300174395035QQihZ020QQcategoryZ 67058QQssPageNameZWDVWQQrdZ1QQcmdZViewItem#ebaypho tohosting)

[killermiller]

You would just use an NPT to flare fitting that you can get from lowe/Ace hardware/Home Depot... Then you just use a hose and your manifold.

[teyber]

But if im brazing, don't i not want the hoses anyplace near because of heat?

THanks for link thats pretty good though :D. So nitrogen-regulator-manifold-fitting-part getting brazed?

[killermiller]

I would just connect the hose between the reg and a 1/4 inch access and slip that into the suction of the compressor and go from there. Not permanent and will still be able to flush out the air and prevent oxidization. Once you braze another access port on then use that one. Then the hose will never be near heat.

You dont' even have to use the manifold. I don't have a flow meter so the manifold lets me control how much flow I want. 20cf should be enough. I have a 40cf I bought used full of nitrogen and 2 recover cylinders for about $140. Not bad since Air Liquide wanted $200 for the cylinder alone. It costs me 80 buck to fill it up though.

[jinu117]

100 PSI delivery is no where enough to do leak testing properly.

[runmc]

You would consider that a purging regulator. It is good for low volumn air flow like you would use while purging. Keep in mind though that you can not get the regulator to delivery any more than 100psi as jin says. I was thinking only 60psi was possible with that particlar. :shrug:

[[XC] gomeler]

Yup that's just like my my CGA320 reg I use for CO2. I rotate the valve all the way out so I'm flowing roughly 5 psi to atmosphere then I have a segment of capillary tubing that's brazed into a fitting that attaches to the regulator. I then use that capillary tubing for all my purging and it works like a charm. Flows enough CO2 to keep the copper safe.

[teyber]

sorry to revive zombie thread: but does anybody recomend argon over nitrogen? this way if i ever get a mig welder it could save a big $$ investment... Any pro's/con's? can it be leak and pressure tested in our systems?

thanks. Reed

[n00b 0f l337]

Works just fine, used with purging on aluminum TIG welding quite a bit if I remember correctly.
Costs more then nitrogen though.

[jinu117]

Argon is more of truer inert gas than Nitorgen for sure and better suited. Except one thing... gas is more expensive. In my case I believe it would add about $80 for monthly gas cost.

[[XC] gomeler]

Yup, argon works fine but costs $$$ It's as inert as it gets though

[teyber]

Argon is more of truer inert gas than Nitorgen for sure and better suited. Except one thing... gas is more expensive. In my case I believe it would add about $80 for monthly gas cost.

monthly? shiot... Im looking to buy a cylinder, are you talking about hiring one? even a little 20cuft one? @nol... this would be for MIG

But if its 80 montly average for use, i think ill stick with nitrogen... (like 80$ in average use of the gas itself after initial cylinder investment)...

[jinu117]

No No, that's not it.
I just use a lot of nitorgen in general... all those purging, triple evac, adds up when you deal with more than one unit a day (be it R&D or what not).
On units that has previously been charged, I found it to better actually do 4 evacs with nitrogen purge to reduce time I spend on pump greatly in total.
Let me see if I can find phone number for one of intersting craiglist ad. The guy delivers tank with full gas for quite decent price (I am not sure if it is just for inland) which I've been thinking about as 80cf one seems too small some times even with backup 22 or 25cf one I have on aside. Except the prospect of taking the damned tank in my car and driving for gas swap later.. -_-;

[teyber]

No No, that's not it.
I just use a lot of nitorgen in general... all those purging, triple evac, adds up when you deal with more than one unit a day (be it R&D or what not).
On units that has previously been charged, I found it to better actually do 4 evacs with nitrogen purge to reduce time I spend on pump greatly in total.
Let me see if I can find phone number for one of intersting craiglist ad. The guy delivers tank with full gas for quite decent price (I am not sure if it is just for inland) which I've been thinking about as 80cf one seems too small some times even with backup 22 or 25cf one I have on aside. Except the prospect of taking the damned tank in my car and driving for gas swap later.. -_-;

haha ah i understand. I am not dealing with 1 unit per day though:eek: Problem is that if i buy nitrogen, i believe nitrogen is lighter then air, therefore it rises. When you want the inert gas to stay down when welding to avoid oxidation, you want something heavier then air, correct? Would it be cheaper to use nitrogen now and get argon if i get a mig welder? or will nitrogen work with mig welder? maybe i should just get arc...

80CUFT is huge! i was originally thinking 20cuft of nitrogen, is that a joke? Really have no idea here.

thanks!

Reed
p.s. that craigslist would be great! and i think im considered inland empire... or at least very close to it.

[killermiller]

Teyber, you will be suprised how fast you will go through it. Especially if you find you like to pressure test at high pressures. Purging, not so much. You just give a big shot and then reduce flow to keep air from settling within the tubing.

As far as the gas density, I don't think you will notice. The flow will go whichever way you point the tube.

[tim-]

as you always have flow you won't have a problem with it to "fly away".. but for sure argon is a better inert gas, it's "heavy" and it's used when you tigweld as well as mig welding.. it depends on material you weld ofcourse..

if you arn't welding (alot more then you braze) I would stick with the nitrogen since it cost alot less and works okay.

[teyber]

alright, sorry to bring back dead thread. I will post pics later.

I went over to airgas. I spend 160$ on a 60cuft cylinder, (which he said is more like 50cuft). I got a 150$ regulator, which he cut down to 90$ for me. he also said that anytime i refill, its only 15$ to refill with nitrogen, and 33$ to refil with argon! im super happy with that. im a little bummed with the 160$ for cylinder, especilaly when i got quoted for 140$ earlier and 90$ on ebay, but im getting this for my birthday and i wasn't paying for it. however i should mention with that earlier quote they said 40$ for every fill-up of nitrogen. So if i ever need argon, a simple drive and 30$ bucks and they swap me for a 60cuft of argon.

Yay! Regulator has delivery psi of 200psi. I spent an extra 75$ to get one over the 100psi one... i won't be getting another regulator. This one is really high quality.

Lol the closest airgas was in the ghettooo, lol.

Pics up later.
Reed

[tim-]

you should invest in a flowregulator for purging. otherwise, nice :)

here the price is the same to fill 5, 10 ,20,50L nitrogen bottles, tha handling cost more then gas.

[teyber]

you should invest in a flowregulator for purging. otherwise, nice :)

here the price is the same to fill 5, 10 ,20,50L nitrogen bottles, tha handling cost more then gas.

yes, my dad was getting a little overwhelmed with the 344$ trip(30 for tax, 44 for 2 propane fillups) so i did not want him to think i was abusing it. I will one-day buy one on ebay. regulator/flowmeter combos have poor delivery psi, so i wanted a good ol' regulator. I will do some research on a flowmeter that screws right on to the regulator, and can handle the 200psi delivery.

p.s. is 200 psi delivery enough for leak testing?

thanks so much. Im darn excited :D
(my b-day tomoro! turn 16)
Bummer tim...

[tim-]

teyber:
you have to use 2 seperate regulators.

i have one for purging and one for pressuretesting. but as I'm lazy i have purging regulator on argon bottle and pressuretest regulator on nitrogen.

[teyber]

teyber:
you have to use 2 seperate regulators.

i have one for purging and one for pressuretesting. but as I'm lazy i have purging regulator on argon bottle and pressuretest regulator on nitrogen.
shoot me:down:
What psi regulator should i use for purging? i guess this super-expensive regulator will be for pressure/leak testing. This sound right? I found for 10$ and 6$ to ship a flowmeter that attached to the regulator but was only 25-psi max delivery. Would this be o.k. and then remove it when im leak testing?

thanks so much for your help.

P.S. do you notice any difference between purging with argon and nitrogen?

Reed

[tim-]

about purging.

I got the argon bottle mainly 'cause of tig & mig/mag welding and there it's a huge differance, wrong gas affect results directly.

for brazing, I havn't notice much difference if any at all since purging gas only have one perpose here, keep oxygen away. I'm pretty sure most hvac shops use nitrogen for purging as well, we did it at school when we brazed vapour units.

if you don't have 2 different bottles go for two regulators or an extension for your. you need about 2-3L/min flow for purging. so, not much at all.

I've seen regulators for about 30-50usd on the net. you don't need much more expensive ones since you don't need 2stage regulator (ie always keep outlet pressure the same when the bottle pressure decrease).

I don't think it's good to mount/dismount the regulators to often, for me it would be 2-3times a day if I just had one bottle.

regards
Tim

[teyber]

about purging.

I got the argon bottle mainly 'cause of tig & mig/mag welding and there it's a huge differance, wrong gas affect results directly.

for brazing, I havn't notice much difference if any at all since purging gas only have one perpose here, keep oxygen away. I'm pretty sure most hvac shops use nitrogen for purging as well, we did it at school when we brazed vapour units.

if you don't have 2 different bottles go for two regulators or an extension for your. you need about 2-3L/min flow for purging. so, not much at all.

I've seen regulators for about 30-50usd on the net. you don't need much more expensive ones since you don't need 2stage regulator (ie always keep outlet pressure the same when the bottle pressure decrease).

I don't think it's good to mount/dismount the regulators to often, for me it would be 2-3times a day if I just had one bottle.

regards
Tim
Thank you!
Yes, if you mig or tig weld i understand how you need argon because its heavier then air, right?
2-3l//m... sweet! will hardly have to fill it up. I do not plan on getting a second tank, this thing was really expensive. Next tanks i invest in will be oxy/acetylene.(one day...). I really think i want to just get a attachment to mine, as really i feel i want to use this expensive regulator. Yeah this is a single stage.

thank you so much for your help my friend.

regards

[tim-]

well I think one part is that is 'cause it's heavier, but also chemistry in there.. I don't have to much knowledge, I just follow the recommendations.

the attachment you mentioned doesn't work since it's just a measuring device and doesn't regulate flow. your pressure regulator isn't precise enough for tune it for flow.

about the dismount/assamble frequently, I don't know how much you use your equipment but if it's just for your own perpose and small scaled building I wouldn't see it as an issue to swap regulator ones in a while.

[teyber]

O.k. well, the buyer doesn't give much info, so i can't tell if its different then the last one, but is this any better?
http://cgi.ebay.com/New-Welders-Gas-Flowmeter-Carbon-Dioxide-Argon-Helium_W0QQitemZ120194572066QQihZ002QQcategoryZ113 743QQssPageNameZWDVWQQrdZ1QQcmdZViewItem#ebayphoto hosting
if not, i will invest in a very cheap flowmeter. And while on that subject, what do you use for connecting? does tubing with a worm drive clamp work? Since, for example, i would be brazing copper tubing to copper tubing, it will not have a fitting. So getting an expensive hose with proper fitting to regulator and on other end doesn't seem practical because one end won't have fitting.

or do you only purge when connecting manifold to access ports?

[tim-]

thats exactly the same idea as you show me in the pm. you need a regulator. I've send you an ebay link to a specific regulator which fit on your cga580 thread.

personally I have quickcoupler on my outlet since I use same bottle for both welding and purging.

I have one sae 1/4" (regular schrader valve for service hose). normally it's possible to use the access valves, but if not you have to tape a hose to a pipe end. you have to improvise sometimes :)