Moisture and POE

[Coolie]

I just heard something that doesn't sit right with me.

"You cannot remove moisture from POE."

I know that POE's are extremely hygroscopic, and that exposure to the atmosphere must be minimised.
It is however inevitable that some moisture will be absorbed by the oil when adding it into the system, or if there is a leak. I really can not see the wide spread use of POE's if you can not remove the moisture from the oil and therefore the system by vaccing/triple vaccing to a decent level, ie 500 microns minimum.

Discuss......

[chemi-cool]

Yes, I've heard that too.

Old Indian said once: Where there is smoke - there is fire....:cool:

When in doubt, always replace it.

[orebanjo]

What are the causes of overheating in reciprocating refrigerating compressors?

[norseman]

Hi Coolie.

I have to store some of this POE and by my ultra low temperature systems, I heat up the compressor and oilseparator with a heat gun and I think that make the moisture to migrate to the surface and by that easier can be pulled by vacuum. I go for lower than 50 microns to be sure. 500 is a no on my beauties.
If you have the moisture up as bad as a liquid as I had in a separator, the water stays under the oil and you can use a vacuum pump for a Year and still have it there. I really could hear every drop of water who
climbed to the oil surface now and then by a ticking explosion when it got into the very low vacuum over the oil surface. (Reason was oil supplied with water)

[dlc]

I read it too, the point the article made was that it
is virtually impossible to pull moisture from poe oil
by system evacuation. which given the conditions the a/c guys work in, makes you wonder why the industry is going to 410a. however system design and driers will do the work. also it seems most guys have a different interpretation of 'a good vacuum', so many micron guages available but no time alloted to actually leave it on the pump to acheive a good vacuum. i remember starting out and looking back it was amazing when helping the journeyman do a compressor change on a rooftop unit, the time it took to have a coffee was long enough for evacuation.
ahh the good old days of r-22

[charlie n]

The root of the problem is that POE oil is not oil. In the presence of moisture, POE lubricant breaks down into acid and alcohol. Neither of these products is very kind to surfaces needing lubrication.
No amount of evacuation will recombine these chemicals back into a lubricant.

[Fett]

I read it too, the point the article made was that it
is virtually impossible to pull moisture from poe oil
by system evacuation. which given the conditions the a/c guys work in, makes you wonder why the industry is going to 410a. however system design and driers will do the work. also it seems most guys have a different interpretation of 'a good vacuum', so many micron guages available but no time alloted to actually leave it on the pump to acheive a good vacuum. i remember starting out and looking back it was amazing when helping the journeyman do a compressor change on a rooftop unit, the time it took to have a coffee was long enough for evacuation.
ahh the good old days of r-22

Aye, although with the right company and a good customer. I have had a fair sized chiller system under a vacuum pump for 48 hours.

[lana]

Hi there,

Charlie n said it all.

If synthetic oil is contaminated with moisture then there is nothing you can do. When it breaks down to acid and alcohol then you have no oil.
The good practice is not to contaminate the oil.

Have a look at the pictures :
http://www.refrigeration-engineer.com/forums/showthread.php?t=21407

Cheers

[lawrence1]

If the system has an oil seperator you can fit a drier in the oil return line to remove moisture,,,works well.