Welding Tips and Tricks

hi guys

first of all, please excuse me if this horse has been beaten to death before but i don`t seem to be able to find anything searching the site (but then i`m not the smartest internet guy) so i need some help. if there`s a thread on the subject please give me some pointers to find it

this is my question, i need a backup bottle of argon and a friend says he gives me an used (tested recently) oxigen bottle, he says that can be used with argon no problem i`m worried about contamination but don`t know so i`m asking

thanks as always appreciate your attention

cheers
pete

penca wrote:hi guys

first of all, please excuse me if this horse has been beaten to death before but i don`t seem to be able to find anything searching the site (but then i`m not the smartest internet guy) so i need some help. if there`s a thread on the subject please give me some pointers to find it

this is my question, i need a backup bottle of argon and a friend says he gives me an used (tested recently) oxigen bottle, he says that can be used with argon no problem i`m worried about contamination but don`t know so i`m asking

thanks as always appreciate your attention

cheers
pete

Nope.
Argon bottles are used only with argon, and Oxy with only Oxy.

I don't think the valve fittings will interchange.

talk nice to LWS exchange oxy for argon of like size pay for the gas

They're all CGA510 inert fittings as far as I know John. An inert bottle is an inert bottle. It's not lined/impregnated like an acetylene bottle is.

Well you're all right to a certain extent, an inert bottle is an inert bottle, but Oxygen is not inert. The valves are different, but the cylinder itself is not. You could buy a CGA580 valve and replace the CGA540 valve that's standard on an Oxygen cylinder, that's one option. The cylinder can then be filled with Argon, Helium, or Nitrogen as well as most Argon/Co2 blends.

As Rick says, you might be better off asking your local cylinder fill if they would trade you for a cylinder with the right valve, as it's not all that easy to remove the old valve, it's hard to hold the cylinder while removing. You can use a tie down strap and strap it to an I-beam or the like, it can be done as long as there's no pressure left in the bottle.

Biggest problem is the fact that most cylinders over 80cf are not owned but leased and if you take it to be filled and can't prove ownership, the cylinder fill will not fill it, or worse, if they are the owner they will keep it all together.

Len

hi guys thanks for your answers

sadly the local fill is not that friendly and trading is not an option (i already asked), the bottle has its "papers" ok so they said they would fill it with o2 or argon no problem. they didn`t mention that the valves are different but they said if i wanted a new valve they could change it (replacement, valve included $40, a new cylinder runs about $350 best price around here). by your answers i see that argon contamination with o2 is not an issue and that`s good. i think it would be nice to keep the o2 valve and make an adaptor for argon but don`t know if it`s possible or legal.
does the bottle needs to be purged or anything before they fill with argon?
thanks again

pete

It really depends on your LWS, I swapped out a few oxygen tanks for argon over the years. Even swapped out an Acetlyene for oxygen once, but that is only because I knew the manager of the store well

Penca,
The correct answer is yes the cylinder should be purged and evacuated by a vacuum pump at least 3 times and then filled. Is this what your local cylinder fill will do, I can't say. If you can wait while they fill your cylinder then you can expect that they don't pull a proper vacuum because this takes time. If they ask you to leave the cylinder, then your chances are better that it was done right.

It's better that they change the valve for you so they can do a proper torque and leak check on the new valve.

Len

len thanks for clearing this up
i`ve been working with this gas company for a long time now i`ll leave the cylinder so they can do a proper job.
thanks

pete