Sources of CO in compressed air

[JohnN]

Apologies if this is not the correct group for this posting. I'm curious what real-world experiences people have had with CO contamination in their tanks.

My understanding for compressors run by electric motors, CO contamination can come from poorly maintained equipment (old oil / old filters) or having the intake poorly placed (sucking in car/smoke/whatever).

If we could exclude the poor placement of the intake, is it really possible to get CO without having the air taste 'funky' ? If the shop is doing partial-pressure blending of EAN, wouldn't that preclude this type of contamination?

 

[BRT]

Consider that a high pressure compressor is a diesel engine without fuel. Add a little fuel in the form of oil and you could get CO.

 

[Doc]

.... is it really possible to get CO without having the air taste 'funky' ?

Yes.​bbbbb

 

[kwinter]

is it really possible to get CO without having the air taste 'funky' ?

Of course. If it tasted "funky" then we would not have had the incidents we have had among extremely experienced divers who have been sickened or died from CO contamination.

 

[KD8NPB]

Hot weather
Intake restriction
Filter restriction

All can lead to high compressor temps which can cause the oil to flash and kinda "smolder" which generates CO.

 

[clownfishsydney]

Of all the hundreds of divers I have been and are friends with, I have never heard once of someone getting CO or knowing of someone who got CO in a tank.

Until I read Scubaboard, I had never actually heard of anyone getting CO in a tank apart from being sucked in from a petrol engine exhaust.

 

[tursiops]

Of all the hundreds of divers I have been and are friends with, I have never heard once of someone getting CO or knowing of someone who got CO in a tank.

Until I read Scubaboard, I had never actually heard of anyone getting CO in a tank apart from being sucked in from a petrol engine exhaust.

You are not very close to Mexico....

 

[bl6394]

<snip>
If we could exclude the poor placement of the intake, is it really possible to get CO without having the air taste 'funky' ? If the shop is doing partial-pressure blending of EAN, wouldn't that preclude this type of contamination?

Partial-pressure blending of EAN involves initially filling with O2 (then topping with Air). Hydrocarbon contamination and / or poor O2 filling technique - could result in combustion and combustion by-products.

Bjorn

 

[JohnN]

Partial-pressure blending of EAN involves initially filling with O2 (then topping with Air). Hydrocarbon contamination and / or poor O2 filling technique - could result in combustion and combustion by-products.

Bjorn

Interesting question, CO "normally" forms with incomplete combustion. In an O2 rich environment, wouldn't things tend to go to CO2 plus a raft of burned hydrocarbon byproducts? Wouldn't this be terribly obvious to the folks filling the tank and the poor person breathing the gas?

 

[Dive-aholic]

Carbon Monoxide « Rob Neto

Of all the hundreds of divers I have been and are friends with, I have never heard once of someone getting CO or knowing of someone who got CO in a tank.

Until I read Scubaboard, I had never actually heard of anyone getting CO in a tank apart from being sucked in from a petrol engine exhaust.

I had a buddy die on a dive and had to pull his body out of the cave after he breathed CO. Since then I've tested every single cylinder I breathe from and make sure my buddies and students also test theirs. I have had positive CO readings in 2 different locations in the world (not both Mexico). Neither was high enough to require not diving but any reading is of concern. I also know of a couple of positive CO findings in Florida. It isn't widespread, but it's there. And my life is worth more than the $150 it costs to buy a CO analyzer.