paint thinner in purging air conditioning pipes

[kefah]

its possible to purge the ac unit pipes with paint thinner
i use it to clean the evaporator of window type ac
so it cleaned it from oils and other contaminant
so what advantage and disadvantage

[Schultzy]

Why would you do that?

[frank]

I recall my tutor at college all those years ago giving me good advice......

"The only thing that should be inside your system is REFRIGERANT."

I always think of this when brazing, opening the system (to reduce air ingress) putting dye in etc.

If it's not supposed to be in there, try to keep it out.

[Frikkie]

Disadvantage is it might attack seals and seats of taps and valves, might leave residue, might damage surface treatments and you might get high on fumes or you might get dead on fumes because it might be explosive.

I would say it is not a good idea. Why do you want to clean out the oil anyway, I really don't understand your ideas here.

[R717]

its possible to purge the ac unit pipes with paint thinner
i use it to clean the evaporator of window type ac
so it cleaned it from oils and other contaminant
so what advantage and disadvantage

Hi Kefah,
Why are you cleaning out these system parts ? Are you retrofitting R134a into old R12 systems and want to remove the old mineral oil so as not to contaminate the new POE oil ?

If you are doing this, i have used R30 (Dichloromethane) for this but it is destructive to any orings , rubber seals, laquer on compressor windings, or any type of paint. Can only be used on all metal parts only. (Evaporators, condensers, pipes.) Not motors, compressors or valves !!

It boils at 40 c so any left inside the part will evaporate with vacuum pumping.

Also dont dump the dirty stuff, boil it, condense the vapor and it will leave the oil and dirt behind and give you clean R30 for the next cleaning job.

[kefah]

i want to use it to remove the oil from condenser and evaporater
so what you advice me to use

[install monkey]

nitrogen..

[Peter_1]

Thinner will desolve the coating on the windings of the compressor. But I don't see any harm for a disconnected condenser or evaporator.

[R717]

Thinner will desolve the coating on the windings of the compressor. But I don't see any harm for a disconnected condenser or evaporator.

I agree, you must be extremely careful what you do with a completely assembled system. But a system that has been separated into its basic parts can be cleaned by means appropriate to each part.

Manufacturers often use many types of solvents to remove machining oils and manufacturing lubricants from parts after they are made, these solvents are not detrimental to the part or the system they will be fitted to as great attention is paid to remove any trace of these solvents.

If you do the same you should be ok, but a solvent to clean a part on the bench would be totally destructive if used to clean the same part while connected to the system.

[kefah]

ok
after i use the thinner
how i will remove it from the condensor

[R717]

ok
after i use the thinner
how i will remove it from the condensor

Drain it as best as possible then blast out any residue with plenty of dry nitrogen with a little heat applied at the same time, it will help boil out anything left. Then vacuum pump it to a low vacuum for 1/2 hour or so then charge it with dry nitrogen and block up the pipe fittings untill you are ready to use it.

Good luck.

[kefah]

thank you all
please close the thread