Posted by Brad Herrick on September 26, 2001 at 21:14:02: via: or 64.50.21.211
In Reply to: Re: HC Accidents ??? posted by Peter Coll on September 26, 2001 at 14:45:35:
I have seen this article before, and it is poor comedy at best. MACS has promoted the big scare tactic for so long I cannot trust them to be factual. here are my questions about this "article" :
1) The complaint was "No A/C", and the article states that the technician was able to generate a "thorough repair estimate" from a "quick visiual inspection" ...... What total BS! With a visibly overheated compressor clutch, several different failures could have occured - some that would not be obvious.
2) He connected gauges to the system, and saw "no pressure" . After this "accident", did anyone investigate the technician's gauge set and the vehicle's service fittings to see why there was no reading??
3) "with no pressure in the system, it didn't seem necessary to connect a recovery machine" - - HUH?? Even if the system had leaked down so close to atmospheric pressure that the gauges did not register, there is still plenty of gas to release. You are supposed to recover to a state of vaccuum before opening the system. According the the Neutronics "test" he vented R12, R22, and R134
4) "When he removed the line, flames and flaming droplets of oil shot out" What EXACTLY was the source of ignition here? Was the technician using a torch? Evert time I start my BBQ, I open the gas valve, and it still takes several hot sparks from the igniter to start a flame. The oil in any A/C system is flammable, and with proper ignition will burn.
5) "Burning droplets melted spots on his plastic glasses" Burning droplets of WHAT? A "droplet" of R290 at 87F does not last but a second, and will not stick to any surface. I have tried to damage a pair of plastic safety glasses with oil heated to 350F, but was unsucessful - I was also unable to keep said droplets burning even while they were at 350F. Oil does not burn well unless atomized, like in a furnace.
6) "The burning oil set the truck on fire" and "There was no damage to the truck" - hmmm, not much of a fire, considering the "melted spots" on his glasses.
7) An entire week passed before the job was re-started. If such a bizzare occurance occured in my facility, I doubt the truck would have been ignored. In fact, such an unsafe item would have drawn lots of attention.
8) "Even though the system had been open all that time, when the discharge line was removed from the compressor, more sputtering oil dripped out" - " Like a sparkler" Was the oil in fact burning? Was it oil at all? The description here does not indicate the presence of either R600 or R290, since it had been open a week at 87F.
9) The compressor and dryer were sealed and sent to MACS. The units were tested for residue after a week of sitting in the sun open. I will assume that the Neutronics equipment is sensitive enough to measure residual ammounts in this condition. The report says "24.7% Hydrocarbons" Since every seal, hose and all of the lube oil in the system is a hydrocarbon, I find this less than conclusive. I personally doubt the results given the long open time. The article even states "if it was packaged properly they can usually what referigerant was in the system.
10) The paragraph guessing at the cause is speculative at best. Perhaps the schrader seals did swell, perhaps not. I have never encountered on that did not work due to seal swelling, but have seen many that leaked. "There's not enough information to determine the cause of the fire" That much is a true statement. The speculation that a chemical reaction caused the fire might hold up if a powerful oxidizer was found in and around the equipment. Of course, samples were not sent to an actual Laboratory, so there is no real factual data available, just the word of MACS. I know of no possible reactions between the components listed that would cause such an incident. To attempt to blame a hydrocarbon referigerant is a joke.
Hydrocarbon referigerants are widely used in the US industrial sector, mostly refineries. In that industry I can find no reports of any kind of fire resulting from a referigeration system. I think the story you makes a good campfire tale, but I suspect the technician was actually injured while lighting his crack pipe.