410a accident...

heating_seattle

I was replacing a coil in the attic of a 1.4 million dollar house when I had a little accident... I pumped all the refrigerant back to the compressor and made sure there was no pressure in the lines, then I attempted to sweat the connections off the coil. The liquid line popped off with no issue as its done 1000 times before, the suction line on the other hand turned into a flame thrower... It shot fire out about 3' into this attic and did not stop for about 10 seconds. I was freaking out trying to put this bitch out. I got the flame to stop coming out of the line and then used the extinguisher to put out the oil fire that developed on the platform. I'm not sure why this happened, I have sweat off fittings after pumping down and making sure its at 0 psi many times before and at most I got a little poof. Needless to say I learned a valuable lesson, always cut lines on an existing system. So while I was frantically trying to put this fire out I took about 5 breaths of the burnt 410a fumes, this stuff is nasty... I am wondering if youguys know how toxic burnt 410a is? About 12 hrs later I went into some sort of allergic fit, I sneezed about 100 times in a 5 min period then my eyes became swollen shut. It took about 12 hrs for the swelling to go away completely. I cant be sure that the two incidents are related but I'm inclined to think so.

nicktech

you'll be dead in a week, get you paperwork in order.


i got dibs on your torch!

beenthere

ROFL....


OP:

Probably more of a reaction to all the dust and fiberglass you stirred up, then to the R410A or POE you started on fire.

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siggy

Like an idiot I once tried to change out a compressor for a thru the wall pakage unit while it sat on a work bench bench in a maintenance room. The room had no windows so once that nasty smoke filled my mouth and I turned to take a breath of fresh air like I would outside I discover there was no fresh air. So I did like any other smart tech would do and tried to take of the suction line real quick. I spent about 2 hours in the hospital sucking strait oxygen. The funny part, I still consider myself an intelegent person!?!

jpb2

Hook up vacuum pump and ley it run while you're torching

beenthere

Don't do that.

It sucks in moisture then.

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jpb2

If you're gonna nitro purge, and tripple evac along with adding a drier. What does it matter? Not trying to start a fight but it can help.

beenthere

You can't remove moisture from POE oil by vacuum.

Filter driers don't remove all of the moisture in just one or 2 passes. It can take days to remove it(and running a good portion of those days). if all the oil is being circulated. If not, then the moisture will stay in the compressor, and you'll end up with a compressor burn out.

As a test. take a mason/canning jar. Put ½ a teaspoon of water in it. Then add 4 ounces of water. Let it sit for 5 minutes. Then vacuum the jar, and see how much moisture you don't get out(yes, you need to set up teh lid to pull a vacuum in advance.


Next, the more moisture you pull in while running the vacuum while your unbrazing, the longer the vacuum pump must run to pull to 500 microns. So you end up adding lots of time to get your vacuum down. And increasing the likely hood of having to change your vacuum pump oil once or twice, while pulling the system down.

It doesn't take much moisture to saturate your vacuum pump oil so that the pump can't pull as low of a vacuum as it should, or as fast as it should.

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phftter

yes, moisture does contaminate oil. if there is a sizeable amount of water in a system, you will need a cold trap to intercept the moisture before it hits the pump, nitrogen for sweeps, and heat.

heating_seattle

Yeah, I have sweat fittings on existing systems many times before with no problem. I think whatever problem I had with the coil trapped alot of oil right at the coil connections explaining the flame thrower... I probably should have hooked up the pump for a couple of minutes then dumped the vac before I sweat the fittings off but I never would have expected what happened.

beenthere

There have been serious injuries from unsweating coils, condensers, etc. When the systems was recovered, or dumped before unsweating.

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wb2

Burning refrigerant in an open flame creates Phosgene gas. A very toxic gas which has been used as a weapon in past wars. It creates a bluish green flame and fumes that burn your nostriles & eyes.....

Every tech breathes some......

Refrigerant oil is flammable isn't it.........

beenthere

As with any oil.

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dodge 2245

this happens all the time. had a tech get burnt on the hand. just cut out the coil and purge lines with nitogen and install new coil with a new dryer.

Archie79

Way back when i was still a "helper" I made the really bad mistake of heating up a sweat fitting and forgetting to reclaim the refrigerant. I ended up with a pressurized flame thrower for about 2 seconds. I ended up with some minor frost bite, and a REALLY PISSED boss. thank god it was R22, and it was on top of a well known and very large hardware business, so i doubt anyone but us noticed!!! (sorry, but im not sure if this site cares if we use franchise names or not?)

artco

Always nick the pipe with a saw or cutter before putting the torch on it.

I had a similar situation with a sweat drier on one stage of a 30 ton RTU.
I was an apprentice at the time and the mechanic I was working with had pumped the system down and had in fact cut the 7/8" tube on the outlet of the drier and had bent it slightly to the side in order to loosen the drier with water pumps and remove it while he tried to un braze the drier line closest to the liquid line shut off valve.
There was no pressure coming through the drier and we thought the system was clear to un braze. Well when he got it hot enough to melt the braze there was a loud bang and the pliers I was holding on the drier flew out of my hands and the drier rocketed straight up about 30 feet in the air. I was thankful we had cut the outlet line or God only knows what may have happened. The drier was plugged solid.
That was 40 years ago and from then on every time I have to remove anything ffrom a refrigerant circuit I cut through (nic) to make sure there is no pressure on either side.
As for breathing in any chemicals it is absolutly no good for your insides especially you liver, lungs and kidneys. Always try to work where it is well ventilated if you can.
Always stop and think before you make your decision how to make the repair. Sometimes we get hasty because we want to get the job done quick that is when we get reckless and accidents happen.

catmanacman

This is the reason you should cut the lines

sktn77a

In this case, carbonyl fluoride, the flourine equivalent of phosgene (carbonyl chloride), from burning R410a. Equally nasty stuff. But unless you had acute symptoms (burning in the eyes, throat and lungs), you'll live!

Don't do it too often, though.........