Cleaning water circuit after a refrigerant leak

[wingman]

Hi,


recently I was called to a small chiller unit from Airwell (CLS302) It is charged with R407C.

It has been build 2006 and in 2007 they had a leak in one of the evaporators. They have changed the evaporator and compressor.

Now my problem, I still measure a leak with a electronic leak detector. Is there a way to clean out the piping if yes what product/method should I use?

Or should I -out of precaution - recover the unit and add a nitrogen charge to leak test the unit once again to make sure there is no leak and leave it with that ?

Kind regards

[Brian_UK]

Cleaning of the inside of the pipework will have no effect on a leak.

Is there evidence of oil etc around where you are detecting the leak?

[wingman]

Well I detect leaks on the purge valve of the buffer tank and close to the automatic purger.

There are traces of oil on the automatic purger. But I believe the previous company never cleaned up their mess.

[rude]

Is the unit working correctly? has it lost any gas? if its working fine id say there no leak and they just haven't cleaned up there oil. Or you could spray the area you suspect there is a leak with soapy bubbles and see if it bubbles up to indicate a leak.

If the unit is short on gas id reclaim and pressure test etc etc

[wingman]

@ rude, the unit is working correctly, the superheat is correct and indicates there is no shortage of refrigerant.

bubbles is no option because it's a closed evaporator. (chiller unit remember) I don't know the correct english term for that type of evaporator it's with plates an it has a water side and a refrigerant side. I would suspect you people call it a plate evaporator. Sorry for not being a native english speaker.

Anyway I have talked to the owner and explained the situation he asked to make a quote for recovering the unit and test both circuits with nitrogen for 24h.

Thanks all for your replies.