Rookie Needs Help ASAP

[JJ_MacD_RMC]

Hello,

I have a handfull of questions about refrigerant recovery, so any help with any of them would be much appreciated.

First, here's what I am doing. I work in a Scrapyard, draining ***** from fridges (among a million other jobs). I was sent to a course to get my ODP card, was given the worst crash course ever, and was sent on my no-so-merry way.

Here are my problems.

1) What is the proper technique for tapping a refrigerator to recover the *****? I was told to simply look at the tubes on the back, find the one that runs from the top of the fridge down to the condensor, punch it, and I was set. Is there more to it? What about vapour and liquid recovery at the same time?

2)I have manuals for both of my recovery units. One is a Robinair, the other is a Yellow Jacket. Both are as old as dirt. In each manual, they say to let the unit run until "system reaches an adequate vac level". What is an adequate vac level? Therre is no indicators on the gauges, and I have no clue how much vac pressure there needs to be.

3) Is there a better puncture tool then the Yellow Jacket vice grips? I can do 3 or 4 fridges then my tips are shot and need to be changed. This can get expensive when I am doing 30 fridges a day, 2-3 days a week...

Sorry for my first post being so long, but I need these answers ASAP. Any help is much appreciated.

Thanks,

J.J. Mac

[chillin out]

3) Is there a better puncture tool then the Yellow Jacket vice grips? I can do 3 or 4 fridges then my tips are shot and need to be changed. This can get expensive when I am doing 30 fridges a day, 2-3 days a week...

I think you may be puncturing the wrong pipe. On the compressor there are 2 pipes and a small stub, either attach onto the stub or go onto the larger of the other 2 pipes.

2)I have manuals for both of my recovery units. One is a Robinair, the other is a Yellow Jacket. Both are as old as dirt. In each manual, they say to let the unit run until "system reaches an adequate vac level". What is an adequate vac level? Therre is no indicators on the gauges, and I have no clue how much vac pressure there needs to be.

You need to get a gauge fitted or use a set of gauges.

Chillin

[JJ_MacD_RMC]

I have gauges for each unit. The Robinair has them built in, the YellowJacket has both built in as well as a manifold. I can see the vac pressure but what is adequate? I don't understand what the actual number should be... Or should it just go to Vac and when it's there, I stop?

As for tapping, I wasn't even aware I could attatch to that stub. And is that a Liquid or Vapour point? Or does that even really matter, considering I am just removing the *****, not replacing it or anything...

[taz24]

I have gauges for each unit. The Robinair has them built in, the YellowJacket has both built in as well as a manifold. I can see the vac pressure but what is adequate? I don't understand what the actual number should be... Or should it just go to Vac and when it's there, I stop?

When you pull the refrigerant from the fridge you only need to go into a slight vac. It depends on the type of gauge you are using but if the vac is measured in Hg then just take it to about 5inch Hg, if the gauges are in bar then just go to -0.2 of a bar.

Does not matter too much just go under the zero.

As for tapping, I wasn't even aware I could attatch to that stub. And is that a Liquid or Vapour point? Or does that even really matter, considering I am just removing the *****, not replacing it or anything...

If you pierce the steel pipe it will blunt the tips of the vice grips, So pierce the coper stub on the comp.
With the fridges off and stood for a while all the refigerant is vapour (unless it is very cold) so it does not matter where you remove it from. You will only have liquid and vapour if the system is running.

Cheers taz

[JJ_MacD_RMC]

Thanks Taz, that helps alot.

[The MG Pony]

When you pull the refrigerant from the fridge you only need to go into a slight vac. It depends on the type of gauge you are using but if the vac is measured in Hg then just take it to about 5inch Hg, if the gauges are in bar then just go to -0.2 of a bar.

Does not matter too much just go under the zero.





If you pierce the steel pipe it will blunt the tips of the vice grips, So pierce the coper stub on the comp.
With the fridges off and stood for a while all the refigerant is vapour (unless it is very cold) so it does not matter where you remove it from. You will only have liquid and vapour if the system is running.

Cheers taz

NO! NO! In Canada BY LAW you must go to 20" of Hg for Low temp gases and 25"Hg for High temp gases ie R-134a R12.

At that vac wack the side of the compressor with a hammer to get the gas out of the oil.

Go into the bullet strainer or the suction line, no where ells. All ways ensure to leave 20% of the tank empty for expansion room.

[JJ_MacD_RMC]

NO! NO! In Canada BY LAW you must go to 20" of Hg for Low temp gases and 25"Hg for High temp gases ie R-134a R12.

At that vac wack the side of the compressor with a hammer to get the gas out of the oil.

Go into the bullet strainer or the suction line, no where ells. All ways ensure to leave 20% of the tank empty for expansion room.

Where is the "Bullet Strainer"? Or which suction line are you referring to?

[Brian_UK]

Hi JJ

I think that we are perhaps overloading you with terms that you don't know yet.

Hopefully this might make things a bit easier for you, anyone else who wants to jump in and help then please do so.

Any schematics about would be useful.

So, here goes...

Starting from the compressor, the black can.

There should be at least two pipes coming out of the can, one slightly smaller than the other. This smaller pipe is the discharge pipe and is the compressor outlet.

This pipe containing hot, high pressure gas, goes to the condenser coil which is normally the black painted pipe coil on the back of the fridge.

In the condenser the gas is cooled and turns into a liquid. This liquid pipe is connected to the filter/drier or bullet strainer. It looks like a section of pipework that is about four times the diameter of the pipe from the condenser and maybe 3 to 4" long.

From the strainer there is a much smaller diameter pipe which is the capillary line which goes to the evaporator (the cold box/coil) inside the fridge.

The liquid goes through the capillary line and expands and changes back to a gas, which cools down the fridge. From the evaporator the pipe returns to the compressor. This suction pipe is the largest diameter pipe in the whole system.

There is often a process tube sticking out of the compressor and this tube doesn't go anywhere. It was used to charge the system first of all and is sealed off after use.

The pipework around the system can be copper or steel or aluminum but the process tube is going to be copper; so use that one to save your piercing pliers from too much damage.

[JJ_MacD_RMC]

As long and tedious as that was to read, I could have really used that a few months back when I started this. Thanks so much, that helps alot.

[Brian_UK]

Sorry about that, it's always easier to talk than it is to write...

[slingblade]

Question.
What do you do with the gas after recovery?
just curious.

[Brian_UK]

Question.
What do you do with the gas after recovery?
just curious.

That's the subject of another thread Sling...
http://www.refrigeration-engineer.co...ad.php?t=14651

[JJ_MacD_RMC]

So now to my other question, are there different tapping tools I can look into, or are the crappy pliers my only option?

[The MG Pony]

the pliers are actualy the good ones!

[JJ_MacD_RMC]

So then it's just my personal errors that are making me think they are junk?

[NH3LVR]

With the fridges off and stood for a while all the refigerant is vapour (unless it is very cold) so it does not matter where you remove it from. You will only have liquid and vapour if the system is running.Cheers taz

If it has enough liquid to reach saturation, would we not have liquid and gas at the same time?