Mineral to Polyolester Oil Systems - Clean up?

[mecassa]

I have come across a few system which have become restricted by oil gelling on the liquid line due to "incomplete" refrigerant/oil retrofits. I am aware the maximum mineral oil content in a changed over poe system should not exceed 5%, otherwise gelling of the oil will occur, however, is there a preferred method of cleaning up this gel? Your input on this matter would be greatly appreciated!

[Mark]

Hi,mecassa
One option is draining the oil from the various components but this is not allways practical.
second is to reclaim the old refrigerant/oil,add the correct charge of replacement oil,recharge with the reclaimed refrigerant and restore operation.The refrigerant will then mix the old oil into solution with the new oil.
After running for a day or so a appropriate compressor drier,oil, filter change is required, this process will need to be done until the oil contaminants level drops to an acceptable level.
I will be interested to hear other peoples methods after doing several R12 retrofits a while ago it took several oil changes. this method obviously cannot be done with every retrofit.
Hope this helps.
Best regards Mark

[frank]

Excuse my ignorance mark but how do you tell when the oil contaminents drop to an acceptable level?

I haven't done many change overs so I'm up for learning

[Mark]

Cant remember where the test kit came from frank

A Refractometer does the same apparently,i havent used one of these though .........yet
Refractometer

Best regards Mark

[dill]

Any good refrigeration wholesaler will supply you with test kits. A good few years back I retrofitted a ransco cascade system from R13 to R23. I changed the oil charge 7 times until it got below 4% on the test kit, I still experienced the "black goo" sticking on the tev filters. The only cure I found was very regular maintainance checks including 6 monthly oil and filter changes. On complex kit chemical clean ups can be very expensive and time consuming. dill.

[Mark]

Any good refrigeration wholesaler will supply you with test kits.

For everyones benefit which one/s .

Best regards Mark

[dill]

mark, I got my kits from RPW MANCHESTER, but if you have any trouble try the web, there are tons of sites listing refrigerant oil test kits. I know at the moment the wholesalers are up "the wall" buying each other out and closing depots down. It's some time since I bought any but I can't see it being a problem obtaining these kits. Regards dill.

[Latte]

Hi Guysm
Dont like to sound pesermisic at all but usually its not worth the hassle. Work out the labour charges to keep coming back, reclaiming, fit new drier & oil, Vac out and regas not to mention the cost of the oil,driers & gas. It would have to be a large system to really make it worth it. Otherwise condemn it

Regards

Raymond

[Latte]

Hi Guys,
Just for info, at the moment the only supplier that i can find that sells Refractometers is HRP Pt No 178799 £380 Retail.

NRS will do a test for you at £75 a time (BARGAIN)

Regards

Raymond

[chemi-cool]

Hi mecassa,

The agent I'm using for a long time is called R-141b, you can read about it here:http://www.atofinachemicals.com/msds/436.pdf

The way I do it, is disconnecting the compressor tubes and the reciver. and the TEV.
Flush the system at least twice. Replace compressor and reciver and you have a clean shiny unit ( inside) ready for any refrigerant.

A bit expensive but fantastic results.

Chemi

[Mark]

Hi,dill

Cant find it in my RPW catalogue ,do you have a part number.

Best regards Mark