This is why I own a CO Monitor..

[Superlyte27]

... and of course, the compressor may be just fine. It's unlikely, but possible that the steel tank has water in it, sat for weeks or months with air under pressure and rusted. As the metal rusts it produces CO. So, make sure your buddy gets a viz on this tank.

Now, this I didn't know. Rusting tanks will form CO? Anywhere I can read documentation on this?

 

[DandyDon]

... and of course, the compressor may be just fine. It's unlikely, but possible that the steel tank has water in it, sat for weeks or months with air under pressure and rusted. As the metal rusts it produces CO. So, make sure your buddy gets a viz on this tank.

I really don't think so.

 

[Superlyte27]

I really don't think so.

I just recreated the process on paper. There is no Carbon at all in the process. So, while there is Oxygen, there's no way to create something from nothing. No way to introduce Carbon into the tank for the C in CO


And yes, I understand that there is .038% of CO2 in breathing air. However, at the end of the process, it's still CO2, not CO, unless my calculations are wrong. I'm certain there are chemists here who can elaborate.


-edit-
I'm still doing calculations on this. I know there's about .02 -2% carbon in Steel. But, rust is FE2O3... no carbon in the reaction.

 

[Suzuki416]

... and of course, the compressor may be just fine. It's unlikely, but possible that the steel tank has water in it, sat for weeks or months with air under pressure and rusted. As the metal rusts it produces CO. So, make sure your buddy gets a viz on this tank.

Nice theory - however that presumes the cylinder doesn't read 20.9%

To be fair - I haven't checked... - as is really unlikely..

but we will see.

 

[DandyDon]

Nice theory - however that presumes the cylinder doesn't read 20.9%

To be fair - I haven't checked... - as is really unlikely..

but we will see.

No, if there was Carbon involved with the suggested process, the amount that would be used to produce 107 Parts Per Million would still be so insignificant that the loss wouldn't measure on a Nitrox analyzer that reads O2 in Parts Per Thousand, which is what one sees when the O2 level is given in Tens of Percent.

However, there is no Carbon involved with the suspect rusting, as explained by Superlyte27 above.

No need in looking for ghost answers, as the common ones will suffice: CO can enter a tank by tainted air intake and/or internal combustion, and the UK only allows a max of 3ppm. The portable compressor you described sounds like a qualified smoking gun to me, for either cause if not both. It would be nice to know what lubricating oil he uses, but I wouldn't expect the truth to be easy to obtain after his negligence almost killed someone.

 

[tanksforthememories]

Thanks DandyDon, I also ordered an Analox Co EII thanks to your endorsement. If you endorse any other publicly traded companies please let me know so I can buy shares....

 

[DandyDon]

Thanks DandyDon, I also ordered an Analox Co EII thanks to your endorsement. If you endorse any other publicly traded companies please let me know so I can buy shares....

I don't know if you'd want to buy stock in them, and there are other brands & models. Just get what it takes and use it on every tank. Easy precaution.

 

[DCRS]

Typically the CO monitor on an air compressor monitors the filtered air between the outlet of the compressor and the banks. It is possible to monitor the incoming air, but isn't usually done, because the compressor runs at a slight vacuum, so there is no driving force to push the air through the analyzer.

It is not likely that your air is medical grade because medical is tested after placing it in the cylinder, each batch fill has a sample analyzed, and then the entire batch is certified. It is way more likely that you analyze your air 2-4 times per year to prove that the process is correct. The standard for such a test is CGA Grade E.

But, as you allude, your air is tested and you have a CO monitor. Nice work.

Thank you ...sorry i misspoke it's modified grade e air ....we have all the extra filters on it .....
Chief was "if I'm going to breath it, it's going to be good air" so he spent the extra coin for the "best" filters ...

 

[SCUBA_Phil]

One other possible source of CO is the filter stack itself. Under normal running circumstances, it will still pull out the normal amount of CO in the air. After a few hours of run time, the filter stack itself will contain a significant amount of CO. If the system is not used for some amount of time (~week) and looses pressure, the CO will start to release from the filter stack. Once the the filter stack is back under pressure, the CO levels will return near zero. Hence it should be a very small amount of air that is contaminated. I always measure the CO level before allowing the air into my bank system. I have measured up to 40 PPM on my own system when it has been shut down for more than month. My system is ~7 SCFM

 

[DandyDon]

One other possible source of CO is the filter stack itself. Under normal running circumstances, it will still pull out the normal amount of CO in the air. After a few hours of run time, the filter stack itself will contain a significant amount of CO. If the system is not used for some amount of time (~week) and looses pressure, the CO will start to release from the filter stack. Once the the filter stack is back under pressure, the CO levels will return near zero. Hence it should be a very small amount of air that is contaminated. I always measure the CO level before allowing the air into my bank system. I have measured up to 40 PPM on my own system when it has been shut down for more than month. My system is ~7 SCFM

So your compressor was putting out some CO for the filter to build up like that. Did you check outflow without the filter? Find the source?

I never heard of the filter itself releasing stored CO. Very interesting, and scary that could happen with a one tank fill.