Pipework Flushing

[frank]

We've got a site where we are about to change 2 cassette systems operating on R22 to new systems operating on R407C.

Due to the length of the pipework runs and the difficulty factor in replacing the pipework we are considering re-using the pipework and have looked at using a flushing agent.

Has anyone got any experience of this? any tips appreiciated.

[botrous]

well we used to flush systems with R22 , i donno about another agents , more information will be appreciated

[chemi-cool]

Hi Frank,

I have written here something about a flushing agent.
It will be faster to go to the shop and read the lable then find the post.

I'll be back soon.

Chemi

[chemi-cool]

It finnished and gone.

The original was R 114 and R 11 so there are many replacements on the market.

Got one for you and I'm sure it will do the job just fine
http://www.honeywell.com/sites/sm/ch...lv/ACFlush.htm

Chemi

[Karl Hofmann]

For automotive work I used to use brake parts cleaner to remove mineral oil when doing a retrofit. I used a one litre pressurised bottle, and force it through at 80 or 90 psi, then I used to pass plenty of nitrogen through to ensure that all the cleaner evaporates.

I have recently built a closed loop flushing machine using an old robinair recovery unit which basically forces your choice of refrigerant (In my case R134a) through the system using the push pull method, but passing the returning refrigerant (and contaminants) through a disposible automotive reciever drier before the vapour is returned to the storage tank, via an oil separator. Seems to me that you could use the similar idea on domestic a/cs, if you join the two ends of the pipework at one end then you can form a closed loop and flush away.

Hope that this helps

[eggs]

Frank, we installed 2 Mitsubishi electric cassettes, specially made for this kind of job.
Just give them the first service a couple of weeks ago. Fine, running great.
If you havn't heared of them, i'll find out which models they were tomorrow, from my sidekick.

Cheers


eggs

[Peter_1]

These units has a special filters mounted in it. You let them run first some days on this special filter and via the shut off valves, you then switch to the other circuit.

[jsimon]

mitsubishi power inverters are specially built for this
use the dip swithes for the first few hours then reset
this remove all the s### from the system

[BritCit_Juve]

If you are replacing the units with R407C units but wish to reuse the pipework then you need to flush the pipework out with a suitable flushing agent such as Endoflush to remove all traces of the mineral oil.
This is usually pumped around the system so it would be as well to leave the evaporator attached untill afterwards.
Alternatively and with a lot more hard work you could change the oil in the current compressor before changing the system. leave it running for a week then rechange the oil. once the mineral oil concentration is below 5% then change the system.
To check the concentration you would need to get a test kit from your supplier and take a sample which you then send off.
The R407C system can cope with a maximum of 5% mineral oil in the polyolester oil.

BritCit_Juve

[Shibhrac]

I would imagine that the pipes which you want to reuse them are still the correct size for the new installations.if they are so i would advice you to use Rx11 the new replacment for R11 which now being band and was using in such flush.