Home fill station for dummies?

[Miyaru]

Someone recently sent me a picture with a bottle connected to their nitrox stick. It was RED, I was like wtf is that!!?? Turns out Canada O2 is red...who knew.

Red is flammable gasses here, and dark-red (not shown in the pdf) is carbonmonoxide.

 

[rjack321]

Well that won't happen. Acetylene takes a very special cylinder. The acetylene is actually dissolved in acetone in the cylinder. And any of the fuel cylinders will have that CGA valve (I forget the series). Propane (the old bottle style) is the same left hand thread as Acetylene.

The acetylene is flowing out of its own special (low pressure) cylinder, out to the torch, then if there are no check valves on the O2 lines a small quantity (in theory) can backflow into the now empty supply bottle. This has happened very rarely and is the reason why check valves are the norm on both cutting torch lines. Its not totally impossible but quite unlikely and part of why they vacuum tanks before refilling. They weren't in control of them and can then vouch for the contents if they don't top them off.

Getting N2 or argon on a helium supply bottle by accident is a legit risk. More than one shop has accidently filled trimix with argon instead of helium. At least around here, other than "o2 is green" there is no color standard for inert gases at all. Back when I stocked argon I made a special CGA580 to female QD fitting for the argon supply while all my heliums were CGA580 to male QD. Made that horrendous screwup less likely.

 

[stuartv]

The acetylene is flowing out of its own special (low pressure) cylinder, out to the torch, then if there are no check valves on the O2 lines a small quantity (in theory) can backflow into the now empty supply bottle. This has happened very rarely and is the reason why check valves are the norm on both cutting torch lines. Its not totally impossible but quite unlikely and part of why they vacuum tanks before refilling. They weren't in control of them and can then vouch for the contents if they don't top them off.

Getting N2 or argon on a helium supply bottle by accident is a legit risk. More than one shop has accidently filled trimix with argon instead of helium. At least around here, other than "o2 is green" there is no color standard for inert gases at all. Back when I stocked argon I made a special CGA580 to female QD fitting for the argon supply while all my heliums were CGA580 to male QD. Made that horrendous screwup less likely.

Is there any chance that a commercial supplier will deliver you argon when you asked for helium? I.e. give you a cylinder that says it's helium, when it's really argon? I'm thinking no, and you're just talking about the possibility of a gas blender at a shop hooking up to the wrong cylinder at the fill station. I'm going to solve that by never having argon.

 

[rjack321]

Is there any chance that a commercial supplier will deliver you argon when you asked for helium? I.e. give you a cylinder that says it's helium, when it's really argon? I'm thinking no, and you're just talking about the possibility of a gas blender at a shop hooking up to the wrong cylinder at the fill station. I'm going to solve that by never having argon.

Well you are going to be in a huge world of hurt if you make trimix with argon by accident. Do you trust the label with your life?

You need to test your helium. Before the days of actual analyzers this was easily done with a balloon.
normal voice = nitrogen
deep voice = argon
squeeky voice = helium

They are all using the same CGA580 valve and its not impossible to get them mixed up at any point in the supply chain. So test your inert gas.

 

[taimen]

Is there any chance that a commercial supplier will deliver you argon when you asked for helium? I.e. give you a cylinder that says it's helium, when it's really argon? I'm thinking no, and you're just talking about the possibility of a gas blender at a shop hooking up to the wrong cylinder at the fill station. I'm going to solve that by never having argon.

They have high quality standards, but anything can happen.
If you are using a divesoft analyser, it should pick this up and display foul air (trimix containing significant argon contamination).

 

[rob.mwpropane]

Well you are going to be in a huge world of hurt if you make trimix with argon by accident. Do you trust the label with your life?

You need to test your helium. Before the days of actual analyzers this was easily done with a balloon.
normal voice = nitrogen
deep voice = argon
squeeky voice = helium

They are all using the same CGA580 valve and its not impossible to get them mixed up at any point in the supply chain. So test your inert gas.

don't forget;

high af voice = nitrous

 

[rjack321]

don't forget;

high af voice = nitrous

Yes but nitrous does not use an CGA 580 inert gas valve. If I pulled the cap off a supply tank and found something other than a CGA540 or CGA580 something is very very wrong.

 

[rob.mwpropane]

Yes but nitrous does not use an CGA 580 inert gas valve. If I pulled the cap off a supply tank and found something other than a CGA540 or CGA580 something is very very wrong.

Gosh...did you really have to swing back to being so technical so fast... can I please have my 30 second chuckle?

Ok...back to your regularly scheduled "Home fill station for dummies" program.

 

[broncobowsher]

My divesoft analyzer will show Argon. I bought a used drysuit bottle once that had an Argon label on it. Hooked it up and sure enough it showed something like 20% Argon. So they got Argon once, used it, topped with air. But more important, the Divesoft did show it as Argon.

 

[stuartv]

My divesoft analyzer will show Argon. I bought a used drysuit bottle once that had an Argon label on it. Hooked it up and sure enough it showed something like 20% Argon. So they got Argon once, used it, topped with air. But more important, the Divesoft did show it as Argon.

Well, isn't that interesting! I would not have expected that.