R407c

[Grizzly]

Is it just me, or has anyone else noticed that.
When pulling a vacuum on a system containing R407c.
The refrigerant tends to boil off more slowly than others.
Causing the Torr gauge it rise and fall more often than other types.
Discounting Moisture as these systems that I refer to have been known to be gas tight and moisture free.

Is it just the properties of this particular refrigerant?
Grizzly

[james10]

i think it's to do with the oil holding refrigerant with 407c if theres a leak the oil stains seem to be a lot bigger than most other refrigerants

[Grizzly]

i think it's to do with the oil holding refrigerant with 407c if theres a leak the oil stains seem to be a lot bigger than most other refrigerants

Spot on. James.
The oil stains do indeed seem a lot larger.
We have some chillers that are over 8 yrs old with large oil stains.
Which have yet to test positive for leaks and have yet to show signs of refrigerant shortage!
Discuss!!!
Grizzly

[james10]

Spot on. James.
The oil stains do indeed seem a lot larger.
We have some chillers that are over 8 yrs old with large oil stains.
Which have yet to test positive for leaks and have yet to show signs of refrigerant shortage!
Discuss!!!
Grizzly

I know what you mean if you ever come accross a Carrier 30gx phase one they have the large external oil pumps they are always covered in oil but as you say never test positive for leaks perhaps another nystery of refrigeration

[monkey spanners]

I don't use R407C so don't know!

I once spent a few hours looking for a leak on a compressor head, oil everywhere, but gave up as i couldn't find a leak no matter what i did!
Went back there years later just as the farmer was topping up the milk pump oil, he would put the jug on the compressor head as he undid the lid on the pump...

[Grizzly]

I
I once spent a few hours looking for a leak on a compressor head, oil everywhere, but gave up as i couldn't find a leak no matter what i did!
Went back there years later just as the farmer was topping up the milk pump oil, he would put the jug on the compressor head as he undid the lid on the pump...

God you know how to live!
The nearest I get to Agricultural is the Dairy's and they can be bad enough!
Do you ever get free samples?

don't use R407C so don't know!

Then you are the lucky one.
Grizzly

[monkey spanners]

Free samples? Depends on the customer, some would charge you for the mud on your boots if they could work out how to do it
I have a few cheese makers who give me cheeses sometimes. I did get some milk from a guy with a jersey cow heard recently which was very nice, he has his own bottling plant and milk round.

I only really have milk in tea or coffee now as it makes me ill if i have too much, I must try and get some work at breweries, that would be more like it


Years ago we did a few new dx milk tanks on R407C, they never worked as efficiently as R22 ones (we had monitoring equipment logging pressures temperature etc) and they suffered a lot of pipe fractures into the condensers, they were all changed over to R22.
All the new ones run on R404A.

Jon

[doctor freon]

Is it just me, or has anyone else noticed that.
When pulling a vacuum on a system containing R407c.
The refrigerant tends to boil off more slowly than others.
Causing the Torr gauge it rise and fall more often than other types.
Discounting Moisture as these systems that I refer to have been known to be gas tight and moisture free.

Is it just the properties of this particular refrigerant?
Grizzly

I thnik some earlier posters are on the right track. It is most likely do to interaction of the R407C and POE oil. The pure HFC's and/or HCFC's (R22) would not behave very differently from each other. However, the HFC solubility in POE is very high, even higher than R22 in mineral oil, so that this behavoir of long pump down time (slow degassing of the oil) is exactly what I would expect. Low temperatures would tend to increase the effect.