adding liquid refrigerant though low pressure side

[coldkeeper1]

I understand that multi-component refrigerants such as r-404a must be charged into the system in liquid form. This can be accomplished rather easily whenever the system is in vaccum or with just a little charge on it. But what happens when the system already contains a good amount of charge? I know how difficult is to add liquid charge through the high side under this situation. A few years ago, I learned about a device designed to allow liquid charging through the low side without risking the compressor. I´ve been unable to find this device with the local suppliers. Does anyone of you would know how to fabricate a similar device, maybe with a capillay tube or expansion valve? Thank you

[Grizzly]

Or just throttle the liquid supply through your manifold gauges.
Meaning regulate the liquid being fed into the low side by viewing it's flow through the sight glass.
By means of opening and closing the supplied valve into the manifold.

Be cautious though as remember you want the refrigerant to flash off in the sight glass before it enters the compressor.
That way any glide becomes irrelevant as the refrigerant can't separate but is being fed into the compressor.
Be careful though you have to monitor and control the flow.
Grizzly

[NoNickName]

What about using a heating tape around the cyilnder? That way you could easily warm the liquid up over the condensing temperature...

[RUSTY]

HI, you could use a reclaim unit to charge liquid into the receiver.

[BUSHY]

i dont think it would be a smart idea to heat a bottle up

[shooter]

Use a roll of copper pipe in between to heat it up you can easily see if going to fast just look at the frost or condens you will see on the pipe. if needed speed put it under water.
if you fill complete bottle do not worry at all as everything will get into the system.
and it will mix up again.

[TRASH101]

If you are "trimming" the charge then do like grizzley suggests or you can buy a charging vessel with a manually adjusted orofice, to expand the liquid.

If you need to put a lot in then in most cases pump the unit down then you can dump liquid straight in.(you might want to let it equalise for a while before restarting:))

[TRASH101]

http://www.stridetool.com/tools/autospecialty/actoolaccess_01.html

This link is one of those charging devices although different to the one I was thinking of.

[Brian_UK]

i dont think it would be a smart idea to heat a bottle upWhy not? it is done a lot of the time.

Specialist heater mats are used.

[Brian_UK]

http://www.stridetool.com/tools/autospecialty/actoolaccess_01.html

This link is one of those charging devices although different to the one I was thinking of.A little off-line with that option I think ;)

[Pooh]

I teach all my students to charge liquid by regulating the flow through the manifold valve, it has worked for me for too many years to admit and I have never damaged a compressor doing it.
Sorry but I do not like the idea of heating the bottle to a temperature were all the component refrigerants in a zeotropic blend are in vapour state as you would have a bomb on your hands, as you raise the temperature you raise the pressure and evaporating temperature.

Ian

Ian

[NoNickName]

Sorry, I didn't make myself clear. I didn't want you to heat the bottle over the critical point, but just above the condensing temperature.

[nike123]

Sorry, I didn't make myself clear. I didn't want you to heat the bottle over the critical point, but just above the condensing temperature.

Heating bottle only works with one component refrigerants.

[Peter_1]

i dont think it would be a smart idea to heat a bottle up
Why not? This is the fastest way but you have to know what you're doing of course. Like everything in our job.
The high pressure will expand to the other side.
We've charged big gas cylinders in packs/racks with 3/8 tube and heating them up with a roof burner.Even the paint on the bottle remains intact.

[philfridge]

[ I´ve been unable to find this device with the local suppliers. Does anyone of you would know how to fabricate a similar device, maybe with a capillay tube or expansion valve? Thank you




You could use a pressure coupling line fitted to your gauges to restrict the liquid while charging. ;)

[Electrocoolman]

Hi Coldkeeper,

Do you have access to 'ITE' tools in your location. They sell a flash charger which is what you want.

http://www.ite-tools.com/

You could try and make one using an inline sightglass, a small length of capillary tube and a couple of brass unions. Possibly use one end section from a copper pressure coupler. The short length of capillary ends just inside the sight glass and 'flashes off' the refrigerant....which you can see and monitor in the sightglass.

[NoNickName]

Heating bottle only works with one component refrigerants.

Why? :eek:

[nike123]

Why? :eek:
I should be more prcise. I meaned zeotropes, because of temperature glide.
If you heat zeotrope mixture, than one component evaporate sooner then other and goes in to system, and other component stays in liquid phase and in charging cylinder.
Therefore, you end up with changed composition of unknown characteristics in your system.

[NoNickName]

Not true. If vapour is superheated more than the glide, you are evaporating all of the components.
Poor zeotropes... they have such a bad reputation.

[nike123]

Not true. If vapour is superheated more than the glide, you are evaporating all of the components.
Poor zeotropes... they have such a bad reputation.

If you have liquid in drum you have saturated, not superheated refrigerant.
At least, that is frequently said here!;)
Also, every refrigerant manufacturer said that zeotropes should be charged in liquid state (stated at packing, or stamped on botle).:eek:

[NoNickName]

Not true. Refrigerant must be charged in liquid state, but at any temperature.

[nike123]

Not true.

What is not true? That refrigerant in drum is not saturated therefore not superheated until it is liquid inside, or that every refrigerant manufacturer said that zeotropes should be charged in liquid state.
I don't get what you are negating here!


Refrigerant must be charged in liquid state, but at any temperature.
Where in my posts I negate this? I only saying that zeotrope refrigerant should not be charged in gas phase, heated or not! My reasoning is stated in above posts.
Did we got here some misunderstanding, because, for both of us, English is not native language?

[NoNickName]

Actually my mistake. I've got little time to post and that doesn't allow me to answer properly.
The cylinder can be heated so that it flows in the circuit more easily. It shall be charged in liquid phase, of course, not in gas phase, but as long as you charge all of the cylinder, it doesn't matter whether you charge liquid or vapour.

[GXMPLX]

It's called a suction accumulator! And if pressure on the vessel is high you use recovery equipment with a suction acuumulator. This should not harm compressor as long as it doesn't overflow, so whatch it.

[nike123]

It's called a suction accumulator! And if pressure on the vessel is high you use recovery equipment with a suction acuumulator. This should not harm compressor as long as it doesn't overflow, so whatch it.

:confused::confused::confused:What are you talking about?:confused:

[GXMPLX]

you get them at www dot emersonflowcontrols dot com, recovery equipment at www cpsproducts dot com

[nike123]

you get them at www dot emersonflowcontrols dot com, recovery equipment at www cpsproducts dot com

Let see if I understand your point.
Do you mean that you use this (http://www.emersonclimate.com/flowcontrols/loadProducts.do?why=storagedevices) when charging liquid in system? Also, you use it when recovering liquid from high side? Is that correct?

P.S. I see that you are situated in UK , so language barrier should not be a problem. Try to be more descriptive. Mind reading is myth.;)

[Peter_1]

Read once this , written by the biggest French gas manufacturer http://www.climalife.dehon.com/do-refrigerant-fluid-mixtures-break-down-if-there-is-a-leak/faq/show/id/1

[GXMPLX]

Let see if I understand your point.
Do you mean that you use this (http://www.emersonclimate.com/flowcontrols/loadProducts.do?why=storagedevices) when charging liquid in system? Also, you use it when recovering liquid from high side? Is that correct?

P.S. I see that you are situated in UK , so language barrier should not be a problem. Try to be more descriptive. Mind reading is myth.;)

Noooou and Yup! I am not even near the UK but 6 time zones away (this explains my delays), language could be a problem mostly because of my &%$ spelling/typing mistakes! And English is a second language for me.
You use equipment the way the manufacturer intends it to be used. If the system is in deep vacuum you first have to breake it letting liquid refrigerant in if you have zeotropic refrigerants and preferably charge full cylinders only (I'm assuming you cannot do this or vapour/liquid charging would not be a problem if you charge whole cylinders). Use the recovery to suck gas from the system (you have to make sure it is NOT taken from a place that mixture gas/liquid could occur, use the discharge valve of the compressor or condenser inlet (some systems could have more issues involved here) and NOT the receiver. Use places where it is in the right composition and use it to presurize the refrigerant cylinder (impossible to use a disposable one). On the outlet of the cylinder you have two choices, you either evaporate the liquid with your manifonld valve and make sure only vapour comes out using a sight glass (slow and requieres all your senses) or you use a suction accumulator between the cylinder and the system and you have your hands free to check the correct amount is being fed. If you are not sure the total amount has come out of the suction accumulator you have to use it like a precharged cylinder.

"Also, you use it when recovering liquid from high side? Is that correct?"
I'm not sure I get your point here I suppose you are asking if the same recovery eq. is used and that is a YES! I use CR700. If you refer to the suction accumulator, I use the cylinder with the recovery machine's suction to the gas valve and a connection to the liquid line of the system to the liquid valve of the cylinder so it acts like a suction accumulator.

All this is described in the recovery equipment manufacturer's manual.
And please don't hesitate to contact me directly if you :rolleyes: disagree.

[icecube51]

just an idea,:o

make in copper pipe a spiral of approx 1mtr , a sight glass and 2 connections whit 2 small refrig tubes of 0.50 cm, both ends whit a valve, one end whit the manifold,so you have for about 2 mtr of charge.
one end at the bottle and the other end at the LP side.

close the LP side en open the bottle,when the tubes are filled, close the bottle en open the valve at the LP side, when needed you can heat up the copper pipe thill there is almost nothing left. close the LP side en start over till it is at the right point.

it works for me to, its slow but accurate.:cool:


Ice

[mahmoud4871]

Or just throttle the liquid supply through your manifold gauges.
Meaning regulate the liquid being fed into the low side by viewing it's flow through the sight glass.
By means of opening and closing the supplied valve into the manifold.

Be cautious though as remember you want the refrigerant to flash off in the sight glass before it enters the compressor.
That way any glide becomes irrelevant as the refrigerant can't separate but is being fed into the compressor.
Be careful though you have to monitor and control the flow.
Grizzly

I am using the same way for charging large tonnage chillers "Air cooled and Water cooled" for several years without any problems.

[haslie]

r407c refill totally liquids.backward the refrigerant cylinder as follow the instruction at cylinder.

[NoNickName]

r407c cylinder does not have to be used upside down.

[nike123]

r407c cylinder does not have to be used upside down.

That depends on cylinder. If cylinder haven't got pickup tube then it needs to be turned upside down.

[sighman]

Read through this thread and thought 'geez some poeple make life hard!' Easiest way is as stated, using manfold to flash off liquid so that vapour enters is the way to go.

Heating of bottle should only be done by hot water or purpose made heater blanket/pad - direct flame not a smart idea!

I remember the device original poster is talking about - they had one at college, from what I remeber it was a glass pot with an oriface in it, perhaps a bit delicate for most poeples work vehicles!

[NoNickName]

That depends on cylinder. If cylinder haven't got pickup tube then it needs to be turned upside down.

I wonder who is selling cylinders without the tube. Major suppliers do not require to put it upside down.

[Porkington]

I have to agree with sighman, why are you people making things so difficult.

The original post doesn't state what the size of the system is. Its pretty much down to common sense.... if you're throwing liquid into the suction/low side of a compressor thats 1HP and trying to kill it, well you might well succeed. I myself have never had any problems charging with liquid into the low side of a system providing you use your brain when doing it. That goes for domestics to 200HP packs.

There used to be an adapter called "Quickcharge" that allowed you to use the vapour side of a bottle and it charged the system with liquid in small amounts. It came out when R134a first came on the scene.

[Peter_1]

Yeah, and the original poster is only 13 years old, so who cares.

Someone read the article I mentioned? You can charge R407c in gaseous phase

[Peter_1]

There used to be an adapter called "Quickcharge" that allowed you to use the vapour side of a bottle and it charged the system with liquid in small amounts. It came out when R134a first came on the scene.
And R134 isn't even a zeotrope, (begins with a '1')

[Porkington]

Yet it is a blended refrigerant which is why they suggested using the "Quickcharge". The fact that it isn't a zerotrope means f'all.

[nike123]

Yeah, and the original poster is only 13 years old, so who cares.

Someone read the article I mentioned? You can charge R407c in gaseous phase
Yes you could but refrigerant need to leave gas cylinder in liquid phase!
That article doesn't refer to charging of refrigerant. It refers to leaking of system.


2 - A mixture with a high variation (for example R-407C) does not break down in a gaseous state in the presence of its liquid, or when it stops. In operation, the probability of a mixture breaking down is virtually nil.

[nike123]

I wonder who is selling cylinders without the tube. Major suppliers do not require to put it upside down.
We have here few Chinese and Indian without pickup tube!

[expat]

I am most bemused by this thread, though have read it with interest.

If you have time to do it the way Grizzly said it would be the easiest and simplest of options. If you don't then you use a recovery machine.

Isn't this obvious?

If you don't have access to a recovery machine, the next most obvious choice is heating the bottle to give it positive pressure over the system being charged. Heating belts are readily available in most sales catalogues.

All these other convoluted ideas (all be them good) are only necessary if you have to improvise to save time. Improvisation which would only be required due to a lack of forethought.

GXMPLX, your written English is of a very high standard. Indeed, much better than that of many native speaking English. Your spelling mistakes are sparse (sometimes ony additions, like an e on the end of break) and only once did I read in your posts a semantic error that sounded a little French. Other than that I honestly thought you were English and in England.

I wish I could write as well in my second language as you do!

ps where's Weston then. I thought you were in a little village in Cornwall.:D

[IceMan08]

whoah, I finally made it to the end of this thread! Just use your gauges! also I think the piece of kit your taling about is called a visi or vizi vapour. Its about the size of a drinks can and you can see the gas going in as liquid and flashing off.

[IceMan08]

found it on just****inggoogleit.com
http://www.trutechtools.com/cart/index.php?main_page=product_info&cPath=15&products_id=175&zenid=b79a1ae76cf6b8ac772cacc609bc4395