Explosion accident

[xeniosavg]

I would like to have your comments regarding the possible causes that may lead to the following accident.


A HVAC technician was injured while servicing a Server Room Air Conditioning unit made by LIEBERT HIROSS model Hiflex 4GOA. The injury occurred when the copper pipe between the compressor and the condenser exploded/ruptured. The copper pipe within the condenser which is located outside the building also ruptured violently.

</O:p
The accident occurred while the technician was about to replace the existing refrigerant (R407c) after a low pressure indication and poor performance by the air conditioner. The technician recovered or removed the existing refrigerant (R407c) and then proceeded with the evacuation of the system. As reported the explosion occurred a few minutes after he began the evacuation procedure.


<O:p</O:pThe following equipment was found at the scene of the accident:



<O:p</O:p

A two stage vacuum pump<O:p</O:p
A gauge manifold<O:p</O:p
A Chlorodifluoromethane R22 Cylinder<O:p</O:p
A SUVA 407c Refrigerant
<O:p</O:p
<O:p</O:p

The technician was slightly injured from the copper pipe fragments while the air-conditioning unit suffered a severe damage.<O:p</O:p

[stufus]

I have no idea what caused this particular incident , but a couple of questions.Are you saying the condenser coil and interconnecting discharge piping both ruptured ? If so was it simultaneous .And this happened whilst under vacuum? What was the R22 cylinder for ,what was in it ,and why was no recovery found at the scene.Was the pipe work electrically bonded.
There was an incident in Dublin a few years ago when a not so smart tech, for reasons best known to himself decided to pressure test a vrf system with oxygen.Needless to say it didn't go to well,the compressor opened up like a blooming flower.And three guys got laced with flying shrapnel.
I suspect there was more to this incident than what has been made public.:confused:

And should the tech not be on the list of what was found at the scene.:rolleyes:
Cheers
Stu

[Peter_1]

Don't post twice your question in different sections

[Brian_UK]

If you had done some searching here you would have found an answer to your story from 2008.

Read here....
http://www.refrigeration-engineer.com/forums/showthread.php?12313-Exploding-a-c&highlight=explosion

[stufus]

If you had done some searching here you would have found an answer to your story from 2008.

Read here....
http://www.refrigeration-engineer.com/forums/showthread.php?12313-Exploding-a-c&highlight=explosion
Cheers Brian
Very interesting read
Cheers
Stu

[big bear]

Was there any record of full/standing charges to what was recovered ? was there a change if there was then a leak was adoment . Did he pressure test with o.f.n (dry nitrogen) or normal nitrogen ??? sounds like he used something else . confused .com ???? something is not right and there is a offset to the story . Certaintly scares me very strange .

[Magoo]

My thoughts exacly Brian-UK,
sounds like system was purged inadvertently with oxygen, oxygen plus oil equals explosion.
Copper pipes do not explode under a vacuum, potentially implode perhaps.

The first thing at a welding course as an apprentice, was do not lubricate regulator fitting onto oxygen bottle. One of those little things that stuck in my mind.

[Brian_UK]

I think the point from the article in the link I gave is that the engineers (sic) concerned had been running the compressor and pumping ambient air possibly against a closed head due to a blockage or shut valve.

Eventually you can reach the point where the compressor mix of air/refrigerant and oil turn into a fuel mix and the compressor turns into a diesel engine - compression ignition.

You don't need to add extra oxygen, it can get enough from the atmosphere.

[NoNickName]

My message wasn't double posted.

[stufus]

My message wasn't double posted.
The Thread starter double posted , Two different sections.;)
I think you may have been found guilty by association :D
Cheers
Stu

[NoNickName]

No, my message was deleted by Brian_UK for double posting, which is not the case.

[Brian_UK]

My message wasn't double posted.
Sorry, my mistake.

The original poster doubled and I deleted/merged his second post. Unfortunately the deletion got attributed to you.

Post reinstated.