System Flush After Burnout

[jdenyer]

Back in the good old days of CFC's and before the prohibition on venting we used to use R-11 to flush a system out after a hermetic burnout. Are there any substitutes that work well? I have seen a product in the Johnstone catalog that is supposed to flush a system after a burnout. Anyone ever use, and if so how did it work? Thanks is advance to all that answer.

[duckman373]

If it's not oil or refrigerant, I would be cautious putting it into the refrigerant system. Most manufacturers also agree with that. Nitrogen, an oil change, and multiple drier changes will take care of the system if you have a burnout.

[selfemployed]

Ditto to 373's post. I know they make stuff for flushing, just don't use it. I remember someone saying ( there is only 2 things that belong in a refrigeration system).

[R12rules]

Do a search of this site for system cleanup. We have chatted about this topic alot!


I do use that flush that Johnstone sells. The non pressurized stuff, that is.

Then I chase it with a gas we all know and love.
Then I follow that up using dry nitrogen.

But I am aware of my system in how it will respend to whatever it is I am putting into it.

Furst you have to isolate your coils, then your controls and the compressor itself. All must be flushed seperately.

The compressor must have an oil change since this is where much of your crap will eventually end up anyway.

Suction filters are great, when you keep an eye on them to avoid severe pressure drop.

I have heard it said that POE will clean a system faster than roto rooter.
That's fine, just as long as you got the driers in place to sop up the slop. So to speak



Stop and ponder what is happening inside the system.

Then ask yourself what types of contamination do you have to deal with on this particular project.

Is it particulates or chemical?

zzzzzz ......... ooops, I ;m falling asleep at the keyboard. guess its time to sign off and trun in for the night.


(long day for sure)

[mikep]

Back in the good old days, you were misinformed about using R-11 to flush a system. R-11 (or any other flushing agent) gets trapped and will pool at low points, bends and other places in the circuit. R-11 mixes with residual oil left in the system and stays there. It does not vacuum off like you think it would. After you evacuate, charge and start-up a "flushed out system" you will notice lower than normal discharge and suction pressures. Sometimes you will see a sudden pressure drop then a surge as the solvent slugs through the txv. Even a tiny amount of flushing agent left in the system will lower the viscosity of your oil. I do not need to explain further what that can lead to.

[rayr]

Mike u are soooooo right about the being misinformed. Was really bad when evaps were in basements where the temp was 70 or below. And it was a Pia disassembling the system to flush it out. I started using oversize suction line filter driers in the late 60's. Have had systems with soot down the suction line a couple of feet. Usually cut out the line when it is that bad. Most times heavy contamination is limited to suction line. Keep a close watch on the pressure drop across drier and all will be well. I have never lost a compressor after changing due to a repeat burnout. And started doing refrig. service and a/c service in 1960.

[duckman373]

Originally posted by rayr
I have never lost a compressor after changing due to a repeat burnout. And started doing refrig. service and a/c service in 1960.
[/B]

And I only pay 10 bucks a month for the info I get from you people. They don't have bargains like that at Big Lots.

[R12rules]

Back in the good ol days ... if you used a flushing agent, like I use today on a small system. And you follow the brief guidelines I wrote, you will never be dissapointed.


Isolate your system components.

Flush, then follow up using that other gas we all use to follow a flush with. (DONT MAKE ME SPELL IT OUT!!!)

Then follow that with nitrogen.

Isolate components. That means they are not connected together.
Each part of the system can individually be fulshed, cleaned and cleared of all residue. No porblema.

The follow up gas, (which is to remain nameless), carries away all traces of the flushing agent. This agent is used in liquid form, but of course.

Be it the good ol' R-11 or this new flush stuff which Johnstone sells. I mean, the non pressurized solution sold in the one gallon plastic bottles.

Finally we use the nitrogen to blow all of the residual "gaseous vapors" out of the components.

This leaves the sysem free to be weled or flared back together again. CLEAN!


No hidden pockets. No trapped oil with flushing agent mixed together.

[rayr]

Glad u said SMALL system!!!

[R12rules]

Originally posted by rayr
Glad u said SMALL system!!!

But of course ... you get something big and the rules go out the window!

I cannot imagine "flushing" a system which had a one hundred pound charge!

"Big" riquires filtering and ... maybe taking a sample of what the various parts of the system are like AFTER the "situation" has occured.

[condenseddave]

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That's it, don't go sticking other crap in there, no matter what the salesman tells you. Even if he buys you lunch.

[mikep]

R12Rules, your procedure is very thorough, but costly and time consuming. Let the drier do the work.

[jdenyer]

Sorry it took me so long to get back here, been really busy.I pretty much figured just refrigerant and oil, but now that I have gotten some responses I will just change the refrigerant and oil and add a filter drier. Thanks to all that responded.

[refer dude 2479]

Originally posted by jdenyer
Back in the good old days of CFC's and before the prohibition on venting we used to use R-11 to flush a system out after a hermetic burnout.

Well when I got in the trade it must have been about the same time as you. We used to do the R-11 thing. It was time consuming and the side effects of not getting all of the R-11 out were almost worse than not doing the clean-up. Then a magical thing happened. Sporlan came out with a service kit that you could use to clean up the systems by running them. It was a 4 core filter shell with flexible hoses at inlet and outlet and an assortment of adaptor blocks that fit just about any compressor suction connection there was. You inserted 4 of Sprolans New Magical suction clean-up cores and ran the system until the oil tested clean, which by the way was tested with a New Sporlan Acid Test kit. The idea caught on and now every one under the sun sells suction filter driers. Either replaceable (the recomended type) or permanant(for you A/C guys) To clean a system it is a mater of driers and cores until; the oil tewsts clean, and then a final oil change. A lot less hassle than flushing and evacuating a forgien gas from the system.

Cleans as it cools.