Milky color in site glass ?

[W.ma.RefrigTech]

I have a 1 1/2 hp semi piped to a 3 glass door freezer and the site glass looks like a milky coffee cream color?? Is this excessive water/moisture in the system mixing with the oil? If it is would you guys throw a special drier in the system after looking for a leak. Wondering if anyone has seen something like this before.

Thanks for your time,
J

[mikeref]

I have a 1 1/2 hp semi piped to a 3 glass door freezer and the site glass looks like a milky coffee cream color?? Is this excessive water/moisture in the system mixing with the oil? If it is would you guys throw a special drier in the system after looking for a leak. Wondering if anyone has seen something like this before.

Thanks for your time,
J
Hello there. You could be looking at a discoloured sight glass or the real colour of the refrigerant. What does the semi compressor oil look like? Either way, pump down and fit a good quality drier and if the sightglass comes apart, clean it or replace it. I'd take an oil sample out of compressor and if it looks the same as was seen in sightglass.. change it. Refrigerant may be U/S (un-serviceable) depending on oil and sightglass results.. mike.

[Emmett]

Sounds like water in the oil, but where could it have come from? Ive seen similar discription on water cooled system after condenser leak.

[NH3LVR]

I have seen this before and I do not know what caused it, but have always been curious.
Many years ago a friend of mine had a three blast freezers using R502 with two 30 Horsepower Copelands on each evaporator.
I noted at the time that the sight glasses had something in them like you describe. I looked at the Bohn literture and it said if this were seen to consult the factory. I did not do that.
Ten years later I was back in a nearby town and I discovered the same units had been moved there. The same color was seen in the glass.
I did some repiping on the units a few years later. while doing so I decided to replace the color elements in the glasses. I took a cotton swab and cleaned the inside of the glass. It wiped out easily and never came back. I do not recall the exact consistency of what I removed.
I do not think that this was water in the oil. The system was dry and the milky coating was not a fluid substance.
Whatever it was was something that the solvent properties of the R502 whould not remove.
After alll that I have no idea what it was.

[AndyHX]

I have it happen to me , when brazing in a new sight glass the oil in system smoked off and coated the inside of glass.

[Magoo]

Hi WmR.
I think you are looking at a stained oil sightglass lens from hot oil deposits, and the foaming oil behind it caused by low suction superheat, or else / plus rapid oil return from separator.
Recommend a pump down, remove and clean oil lense on compressor, a oil change with recommended oil. Check the sump heater is working, and recheck system. If still foaming do super heat checks on expansion valves to determine which one is saturating back.

[modvalve]

i have seen it when converting r12 units to r134a if you dont do at least 2 oil changes the mineral and synthetic oils when mixed together cause the refrigerant to go a milky colour