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Welding Cylinder Question
- Thread starter fatboy99
- Start date
NASTYZEN
Well-known member
Oxy. usually around 2500 psi. and Ace. no more than 300 Psi.
rlitman
Well-known member
It's that "usually" that gets ya.
It depends on the neck ratings of the tank, and the temperature.
Acetylene will always be the same, but temperature will change the "full" pressure a whole lot.
The oxygen, argon, and C25 (and other high pressure gases) will be filled to what the tank is rated for. Look here:
http://www.airgas.com/content/details.aspx?id=7000000000243
The service pressure is stamped on the cylinder, however if it is marked with a +, then it is actually 10% more than that number in PSI.
It depends on the neck ratings of the tank, and the temperature.
Acetylene will always be the same, but temperature will change the "full" pressure a whole lot.
The oxygen, argon, and C25 (and other high pressure gases) will be filled to what the tank is rated for. Look here:
http://www.airgas.com/content/details.aspx?id=7000000000243
The service pressure is stamped on the cylinder, however if it is marked with a +, then it is actually 10% more than that number in PSI.
Jim Johnstone
Well-known member
Read the numbers on the shoulder of the cylinder, it should say something like 3AA-2400 or 3AA-2015 etc. The numbers after the 3AA is the working pressure.
trbomax
Well-known member
Oxy,argon, and mix tanks can be as low as 1800 if they were filled from a manifold.A lot of places will fill this way instead of sending them back to a filling station that has a pump.What they do is connect 3 or 4 tanks on a daisy chain with the first the "fullest" and the last "empty". As the tanks equalize out,they are swapped back up the chain,and the formerly "full" tank sent out.They can "fill" 3 emptys from 3 fulls and get 6 to send out,but they will only be at 1800 instead of 2200.
Acetelyne tanks are sold by volume,not pressure. They are filled with cotton saturated with acetone,this absorbes the acetelyne gas. There will always be a chalked number on the side of the tank that tells how much was put in.I always sort thru and find the "heavy" tank, since the price is the same.
edit) bottom line is that if your getting low pressure tanks all the time,find a new supplier thats not stealing from you. We would do this with ourown tanks if we were getting low on numbers or needed one for a service truck that was mt,but we were stealing gas from ourselves,a different thing altogether!
Acetelyne tanks are sold by volume,not pressure. They are filled with cotton saturated with acetone,this absorbes the acetelyne gas. There will always be a chalked number on the side of the tank that tells how much was put in.I always sort thru and find the "heavy" tank, since the price is the same.
edit) bottom line is that if your getting low pressure tanks all the time,find a new supplier thats not stealing from you. We would do this with ourown tanks if we were getting low on numbers or needed one for a service truck that was mt,but we were stealing gas from ourselves,a different thing altogether!
Last edited:
OK I just looked at the tank's the oxygen tank is stamped 2015 the argon and argon/co2 tank's are stamped 2265. My pressures have been between 800 psi and 1500 psi from my current supplier. We use Praxair at work and Ive never picked up a cylinder that has less than 2000 psi. By the way the tank I picked up that had 800 psi was returned and was a lengthy discussion about how I had used some from the pick up time and return time That was a total of 20 min. I live 10 min from the supplier. I own all my tank's so I think Its time to switch suppliers.
Murphy4570
Well-known member
Yeah, F that supplier. They are outright stealing from you if they're short-filling the tanks like that.
rlitman
Well-known member
800 PSI. Yeah, he's either trying to rob you blind, or a complete idiot.
I know that my supplier has 6000+ PSI tanks on his filling station with a regulator, so he can fill my 2015PSI tanks up completely using the daisy chain described by trbomax.
All I can think, is if he were to transfill from one tank to another in that method, but do it way too fast so that the contents of your tank got very hot, then your tank could appear to be up to maybe 1800PSI when he's done, but under 1000PSI after it's cooled down. That's my only guess, but filling tanks too fast (ESPECIALLY with oxygen) is ridiculously dangerous.
When I'm getting an oxygen tank refilled (on the days that I don't just exchange), it takes almost half an hour. My tank is placed in a water bath to keep it cool, and a rule of thumb I recall was to fill high pressure tanks at no more than 100PSI per minute (don't hold me to that).
I know that my supplier has 6000+ PSI tanks on his filling station with a regulator, so he can fill my 2015PSI tanks up completely using the daisy chain described by trbomax.
All I can think, is if he were to transfill from one tank to another in that method, but do it way too fast so that the contents of your tank got very hot, then your tank could appear to be up to maybe 1800PSI when he's done, but under 1000PSI after it's cooled down. That's my only guess, but filling tanks too fast (ESPECIALLY with oxygen) is ridiculously dangerous.
When I'm getting an oxygen tank refilled (on the days that I don't just exchange), it takes almost half an hour. My tank is placed in a water bath to keep it cool, and a rule of thumb I recall was to fill high pressure tanks at no more than 100PSI per minute (don't hold me to that).
Jim Johnstone
Well-known member
Any have decent fill operator with a cascade system should be able to hit your rated pressure within 20 PSI. I work for a scuba shop and do tons of air/oxygen and mixed gas fills and it's not rocket science.
You are right that if it was hot filled, it will cool and the pressure will drop, but not that much. A tank hot filled to 1800psi might cool to 1500 or so, if he was getting 800, he's being flat out ripped off.
A few other things to note, 100psi/minute is the rule of thumb with O2, air and inert gasses we fill faster, and it's been pretty widely accepted in the scuba industry that submerging them in water during the fill is a waste of time. The only thing that THEORETICALLY could help is if the tank blew up, the water might absorb some energy, but if you're near it when it blows, you're up **** creek.
You are right that if it was hot filled, it will cool and the pressure will drop, but not that much. A tank hot filled to 1800psi might cool to 1500 or so, if he was getting 800, he's being flat out ripped off.
A few other things to note, 100psi/minute is the rule of thumb with O2, air and inert gasses we fill faster, and it's been pretty widely accepted in the scuba industry that submerging them in water during the fill is a waste of time. The only thing that THEORETICALLY could help is if the tank blew up, the water might absorb some energy, but if you're near it when it blows, you're up **** creek.
800 PSI. Yeah, he's either trying to rob you blind, or a complete idiot.
I know that my supplier has 6000+ PSI tanks on his filling station with a regulator, so he can fill my 2015PSI tanks up completely using the daisy chain described by trbomax.
All I can think, is if he were to transfill from one tank to another in that method, but do it way too fast so that the contents of your tank got very hot, then your tank could appear to be up to maybe 1800PSI when he's done, but under 1000PSI after it's cooled down. That's my only guess, but filling tanks too fast (ESPECIALLY with oxygen) is ridiculously dangerous.
When I'm getting an oxygen tank refilled (on the days that I don't just exchange), it takes almost half an hour. My tank is placed in a water bath to keep it cool, and a rule of thumb I recall was to fill high pressure tanks at no more than 100PSI per minute (don't hold me to that).