Fisheries Queensland director killed by Carbon Monoxide

[kelemvor]

I've been testing tanks for CO for about 2 years now and found 2 contaminated tanks (filled the same day). The shop overhauled their compressor and refilled the tanks.

I've heard of at least one incident at Wayne's in cave country... I don't remember the details but they were posted on SB and CDF.

CO happens. If you test your tanks, then it's not that big of a deal when it does happen.


Oh, since it has come up in the discussion. The compressor used to fill my two tanks was electric. We assume that the CO got into his intake on top of the building, but aren't 100% certain.

 

[DandyDon]

Oh, since it has come up in the discussion. The compressor used to fill my two tanks was electric. We assume that the CO got into his intake on top of the building, but aren't 100% certain.

If an electric compressor overheats, it can partially burn its own oil, producing CO internally. Not well known, but factual - and who knows how common.

 

[kelemvor]

If an electric compressor overheats, it can partially burn its own oil, producing CO internally. Not well known, but factual - and who knows how common.

Not the first time I have heard about that, and I'm not even a "professional" diver. It could be what happened in this case, or it could have come from the intake. I doubt the shop knows - if they do then they never told me.

I think I remember the incident at waynes being some kind of internal flash fire relating to oxygen in the nitrox bank or something along those lines. That's probably where I read about compressors burning their own lubricants, too.

 

[OzMikeM]

Has anyone tried using one of the CO meters available on Ebay.

Something like this?
LCD Digital Carbon Monoxide Handheld Meter CO Gas Tester Detector MetF0 | eBay

For that price even if they aren't 100% accurate they should at least indicate a problem with gas.

 

[DandyDon]

Has anyone tried using one of the CO meters available on Ebay.

Something like this?
LCD Digital Carbon Monoxide Handheld Meter CO Gas Tester Detector MetF0 | eBay

For that price even if they aren't 100% accurate they should at least indicate a problem with gas.

Yeah, maybe. I realize that a lot of quality electronics are made in Malaysia, but confidence in a product made there and shipped from there by a company I've never heard of is challenged. Do you know much about the company?

Basic Error: +/-5%(f.s),+/-10ppm: So if it reads zero, you figure that it can't be over 10ppm? Wonder how accurate it is after a year?

Response Time: 60 Seconds: It seems that you could direct tank air towards the sensor for a full minute, if you weren't voted off of the boat. If you're going to try this one, I'd suggest gallon ziplock bags.

1. Turn the unit on and place it in the bag;
2. Crack the tank before placing bag over less you open too fast and send the bag flying. I've done that.
3. Take at least one bag/day for your trip and carry a spare in your dry bag as they develop leaks.
4. I like the bags that have a zipper type handle on the zip.
5. Watch you watch to ensure you wait a full minute.

Would you really trust it, enough to call a dive if it gave a 50ppm reading?

 

[cruiser]

I've got my Analox CO tester, even though they're not manufactured anymore. It's working fine and Analox still does maintenance, although it doesn't require much.

 

[2airishuman]

I'm curious as to the mechanics of how tanks filled from the same compressor could end up with markedly different levels of contamination. Do you know how that works?

There are a number of possible causes.

Let's start out by making it clear that there is hopcalite in the filtration system, which converts CO to CO2, rendering it non-hazardous at concentrations ordinarily encountered. Therefore, in order for CO to be present in a dive cylinder, one of five conditions must be present:

1. An intentional decision to use unfiltered air, or use air that was not filtered for CO.
2. A mistake in operation that led to the filtration being ineffective, such as using the wrong filter by accident, or having the input and output lines to the filter column reversed, or using bulk media and packing it incorrectly.
3. A mechanical failure of the filtration system, for example, a failure of an O-ring allowing unfiltered gas leak past the filter, or the failure of the pressure maintainer valve allowing a low pressure/high velocity condition to develop
4. Exhaustion of the filter media by saturation with a large amount of CO contamination over a protracted period of time.
5. A reaction that produces CO occurring downstream of the filter, such as hydrocarbon contaminants spontaneously combusting in the presence of highly oxygen-enriched air.

Of these, #3 and #5 can be specific to a particular cylinder of air.

As for where the CO comes from, well, either it's in the input air stream or it's produced by the compressor. Either can be a problem, and either can be transient. Input airstream can be affected by wind direction, whether the water heater (etc) is running, and whether there's a truck with the engine idling at the loading dock. Elevated CO from the compressor comes with overheating, so it gets worse with higher output pressure and with longer run times. Two cylinders on the boat may have been filled at the same time but one filled from the cascade with last night's air and the other filled from the compressor with today's air.

 

[Johnoly]

..I've heard of at least one incident at Wayne's in cave country........

Please understand I've never heard of a verified CO tank at that place so I'm not calling you out. {links are welcomed} But the system in place there is one of the world's largest cascade systems and in the old day's before the inline analyzer, we used 3-4 T-bottles and "moved the cup" method to fill our tanks. A multi bank system gives the diver so much more dilution of CO from flashover. To get a bad reading from one of the world's largest cascade systems, I would bet the compressor would throw it's 3rd/4th stage piston and break before being able to get a detectable hit of high CO levels in the bank. I have never seen or heard of a direct compressor fill at that facility and why would you with that massive banking system.

A flashover is a very violent reaction and expansion inside a piston stage and will almost always results in damage to the cams / crank in a very short time. That is why the overwhelming majority of high CO readings DON'T come from banked systems, but rather 'direct fill' to the tank. That facility has over 100,000 cubic feet of stored gas onsite! It's next to impossible to generate a high enough CO reading. Again, I'm not calling you out cause I haven't heard of it, but I've filled many times at the facility you mentioned and it's one of the top rated, largest in the US and known worldwide.

 

[Jack Hammer]

Please understand I've never heard of a verified CO tank at that place so I'm not calling you out. {links are welcomed}

It happened, I was there and personally know and spoke with 2 individuals who got CO in their tanks from it. Mine were fine, I filled and analyzed them before the incident. IIRC a filter stack melted, somewhere i have pictures I took. Wayne didn't hide it, he started calling and letting everyone know what happened and made sure the word got out. Considering how on top of maintenance he usually is and how many systems he's set up for others it speaks volumes about the saying that it can happen to anybody.

 

[Anthony A.]

I've tried a few over the years. The PocketCO greatly disappointed me. Some that I found very usable...

Analox made a great one. No longer available as the market balked at the price, but if you can buy a used one, they will still help with updating.

The CooTwo is outstanding. You can get it in a model that tests of CO and O2 at the same time.

The Sensorcon works great and is the most economical. You can make an adapter to fit a tank, but I just use one gallon Ziplock bags - a new one every day as they do wear out quickly. Carry it in the bag, crack the valve before placing the bag over, catch a bag full of air, and watch for change. The reason I say crack before placing is I once shot a bag & PocketCO overboard when I opened the valve.
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I appreciate that these may be difficult to find and service where you are, but there are other good ones. Good luck on your search.

The cootwo looks excellent with the lpi adaptor but price + having to change the sensor every year would be way to expensive for me.

The sensorcon seems to fit the bill price wise. Im sure I can make an lpi adaptor to work with it. How often do you have to recalibrate it and is the only method of doing so using a gas container like shown in one of their videos? Does the sensor ever need to be changed?