Argon detection

[krafft.t]

Hello everyone,

I got a question about the safety when working with gas like argon. I use my TIG welder in my cellar (basement) and for my safety I have a ventilation system.
Because argon is heavier than air the ventilation system sucks in air from the bottom and the ceiling of the cellar. Fresh air is automatically pulled in from an opening on the other side of the room.

I was wondering what would happen when I forgot to close the argon and for any reason the argon would go out of the bottle and stay in the room (ventilation system turned off). Is there a way to detect the argon?

As far as I know the only way to measure it would be to measure the level of oxygen in the room. If there is too much argon the oxygen level would go down.
Can I also use a carbon dioxide detector to do the job? I don’t think so but I wanted to be sure.

I would like to have a detector that monitors the room for gas to be sure that everything is alright.

Thank you for your help.

[Country Metals]

An oxygen detector is what you want. It's not just the argon, welding in a small area isn't too good. Do you have a timer on your filtration so it runs for 30 minutes after your done.

An argon sensor at the bottle will detect a a small leak long before the o2 sensor does.

Keep a bottle of soapy water around and use it often.

Sent from my SM-G960U using Tapatalk

[SlowBlues]

Welding in a basement is a perfect storm of potential disasters, but I'm sure you're well aware of that and take proper precautions. I would use the oxygen sensor bc it's much cheaper than anything that can detect argon, maybe a couple for redundancy. use soapy water or bubble blowing liquid from the dollar store often as stated above. also having a way to remotely turn on your ventilation before you go down would be a good idea, as was the timer for after you leave. assuming the basement is also used for regular basement duties I might set the bottles outside and run a long air hose in if it was at all feasible. I rarely adjust gas after the initial opening of the valve for the day so not too inconvenient, though you might forget to turn off the tank if it's somewhere else.

[thegary]

oxygen sensor with a low limit alarm around 19% located about 2ft off the floor unless you have pets down there too. If so then put it a few inches off the floor. Argon is heavier than air so it will collect on the floor area first, the more you introduce the higher it will go and displace oxygen in the process.

[FlaJoe]

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[rlitman]

oxygen sensor with a low limit alarm around 19% located about 2ft off the floor unless you have pets down there too. If so then put it a few inches off the floor. Argon is heavier than air so it will collect on the floor area first, the more you introduce the higher it will go and displace oxygen in the process.

I've covered this subject in other threads here, so I suggest you use the search function.
However, to reiterate:

1) CO2 has the same molecular weight as argon. If CO2 does not pool in your basement, then argon will not either.
2) Your exhale more gas than your TIG welder does, though only perhaps 5% of your exhaled breath is CO2. So, assuming you are running your TIG welder CONTINUOUSLY, it displaces as much oxygen as 20 people. But just about nobody TIG welds at 100% duty cycle.

Back to the OP, your ventilation sounds good for the argon issue (a basement is NOT a "confined space"), but not necessarily from other welding issues (that's a subject for a different thread). There's no harm in monitoring the room's oxygen level.

How big is this room? Work it out in cubic feet, and then see how much releasing an entire argon cylinder int he room will dilute the air. My guess is that unless it's a REALLY small room, it's insignificant.

[shasti]

You can have a portable gas leak detector to identify argon gas leak.

[Munkul]

without a ventilation system switched on, there's a risk of argon (or CO2, or nitrogen) being released faster than it can dilute into the air mixture. That's when it starts pooling at the bottom. It's a well documented problem with purging tanks and vessels in industry.
The most common and cost effective method of detection is with an O2 monitor, as suggested. Problem with personal O2 monitor, is that it needs calibrated (or "bumped") regularly, or it's sensor reading drifts off. It's not a problem as long as you know how to use it properly. I don't have any experience with fixed installations.

I work with, and am up to date with, current confined space practice.
A basement isn't a confined space until it has a specified risk. If there's a risk of low oxygen levels, then that's a specified risk.
If you have several mitigation factors, such as good ventilation/extraction, AND a monitoring system, as well as your own common sense checking the gas valves are turned off, leak checking etc, then that risk suddenly becomes very low It sounds like you're going the right way about it.

If it were me on my own, i'd be happy enough with the ventilation system, leak-checking and remembering to turn the gas off after use.
But if there's more than just yourself to think about it, then I'd be seriously thinking about a fixed O2 monitor and alarm.

I don't think a personal monitor is the right way to go - you'll get utterly sick of using it every time and there never being a problem, and end up discarding it.

[William McCormick]

without a ventilation system switched on, there's a risk of argon (or CO2, or nitrogen) being released faster than it can dilute into the air mixture. That's when it starts pooling at the bottom. It's a well documented problem with purging tanks and vessels in industry.
The most common and cost effective method of detection is with an O2 monitor, as suggested. Problem with personal O2 monitor, is that it needs calibrated (or "bumped") regularly, or it's sensor reading drifts off. It's not a problem as long as you know how to use it properly. I don't have any experience with fixed installations.

I work with, and am up to date with, current confined space practice.
A basement isn't a confined space until it has a specified risk. If there's a risk of low oxygen levels, then that's a specified risk.
If you have several mitigation factors, such as good ventilation/extraction, AND a monitoring system, as well as your own common sense checking the gas valves are turned off, leak checking etc, then that risk suddenly becomes very low It sounds like you're going the right way about it.

If it were me on my own, i'd be happy enough with the ventilation system, leak-checking and remembering to turn the gas off after use.
But if there's more than just yourself to think about it, then I'd be seriously thinking about a fixed O2 monitor and alarm.

I don't think a personal monitor is the right way to go - you'll get utterly sick of using it every time and there never being a problem, and end up discarding it.

A small cellar has over 6,000 cubic feet of air in it. A T-tank holds 345 cubic feet, it will not be the Argon that kills you.

Sincerely,

William McCormick

[Munkul]

https://www.hse.gov.uk/welding/asphyxiation-hazards.htm

[Kelvin]

So...I guess the bottom line is, "Don't leave the argon bottle valve opened, the torch valve opened and/or the tig pedal depressed with the machine running and solenoid open and then pass out drunk on the floor of a very small, tightly-sealed room."

Sounds like that needs to be a lockout/tagout operation to me.