Damn! :shocked2: Yes, I know you are an expert, but that is just wrong - and so illustrative of why we can't fix this ongoing problem.
I guess you didn't know that an electric powered compressor can produce dangerous CO levels internally?
Yep. Thank you.
I repeat! If you are using the proper oil, and you are using the proper compressor for the job at hand, it should never overheat. If you have a compressor with a 2 hours service rating, and you are trying to run it 12 hours, you are using the wrong compressor. This isn't the compressor's fault. It's also not the oil's fault. It's your fault for using the wrong tool for the job.
If you need a compressor that will run 20 hours straight, without overheating, there are a ton of them out there. I can take pictures of ours if you like. It can run for 20 hours and the temperature doesn't climb even a degree.
Now, if you are running a compressor that hasn't been serviced, needs a valve job, ring job, has wrong oil in it, or only has a short service rating and it starts to overheat, well, then yah, you MAY get incomplete combustion of the oil causing CO. But who's fault is that?
---------- Post added July 3rd, 2013 at 07:06 PM ----------
Aren't there special lubricants which are supposed to mitigate the risk of oils breaking down into co2?
Yes, it's very hard to get the proper oils to burn. We used Monolich(sp) for years. I'm told there's better stuff out now.
---------- Post added July 3rd, 2013 at 07:09 PM ----------
Yes, except the diver never knows what was used, how the compressor was maintained, etc. unless he happens to also be the compressor operator. There is only one way to know if a tank is safe, by testing the gas in the tank. Every tank used, even if the other hundred off the same compressor were ok.
The oil we use is readily available. The service interval is on a placard right on the compressor with last service and next service date, the air quality report is in plain sight. However, unless people know what they are supposed to be looking for, none of this information tells the general public a single thing. They don't know what's acceptable for oil. They don't know how often that oil should be changed, or how often the compressor gets a valve job or what grade of air they should be breathing.
Education, like what is available on a lot of SB, helps.
---------- Post added July 3rd, 2013 at 07:14 PM ----------
Unfortunately that is not the case. There are numerous examples of electric-motor driven compressors which have produced carbon monoxide internally. The most famous one is likely the Montreal fire service compressor that would reliably produce CO only 3 hours into a run when the compressor reached a temperature hot enough to autoignite the compressor oil. Carbon monoxide levels as high as 250 ppm were found in the SCBA tanks.
Carbon monoxide and water vapor con... [J Toxicol Environ Health. 1997] - PubMed - NCBI
Poorly installed compressors with little to no ventilation and running mineral oils will reach temperatures which can ignite the lubricating oil. If there is no catalyst in the purifier the CO will go straight into the tank or storage banks.
DAN has published two articles now over the last decade on the rate of CO contamination in dive air and the laboratories (TRI and Lawrence Factor) report a failure rate of 3 percent at 10 ppm. The bulk of compressors out there are electrically powered so the large majority of those failures are from electric and not gas-powered compressors.
Here is a CO poisoning incident which was from an electrically driven compressor where the final stage malfunctioned (personal communication).
August 2008 Volume 18 Number 8
I think you guys are missing my point.
A properly functioning compressor should not produce CO due to overheating. YES GIVEN HIGH ENOUGH TEMPS EVEN THE BEST OIL CAN START TO BURN...
My point, which clearly wasn't stated clearly (based on all the responses) is that a compressor shouldn't be overheating. Why is the compressor overheating? It shouldn't be overheating just because it's running long is my question and point. Even then... lets say a compressor is overheating, how hot is it getting? Why is it getting hot? Bad oil, wrong oil, bad valves, mechanical issues, consumer model instead of commercial model trying to run all day. What's the greater issue?
---------- Post added July 3rd, 2013 at 07:21 PM ----------
I can't find the flashpoint of Del1 Synthetic Oil anywhere. Anyone know what it is? Just wondering when it starts to break down.