hoe do you clear domestic blockages r134a etc.

[john squibb]

i frequentlyu get situations of not cold / not freezing etc,
gauges read deep vacuum / patial vacuum more gas dose not help
evacuate& recharge does not help
i suspect capilary blockage duh!
but how do you clear it what tool is there?
please help guys
many thanks john in the uk

[bernie]

There is a product out there Rx-11 flush.
You inject it in to an open system, after it is injected it will slowly boil off and attack the sludges that block your cape tube.
Its important to back it with nitrogen to aid in pushing the junk out of the open line.
If possible the best thing to do is replace the cap. Some guys like to install a new liquid line, t.ev on the evaporator.
If you can, sell a new condensing unit with a reciever on it, and then a new T.E.V. ,now your in business.
All are cheaper than replacing the entire box.

[bernie]

Never mind, just saw (domestic blockage)!!!!
Throw it out, unless its yours. The repair will cost more than a new refrigerator.
Bernie

[cpt. cascade]

Hi im new to your forum. my name is john and ive been working on cascade systems, ultra low refrigeration, for 9 years. any way


Oil loging is a big problem when you start getting down around -60 c. Alot of the time we are able to defrost the unit alowing the oil to migrate back to the compressor, however much of the time the reason for the oil log is that the oil has lost some of its vescocity. I think part of this loss is due to the actual freezing of the oil.

In the field, if you have to get it working right then, we will add either propane or ethane, pentane is also used,. Now keep in mind this isnt propane for your barbeque, this is a much cleaner labratory grade. Notice these are all petroleum products, that is what gives them the flushing capabilitie,.


Now, depending on if your restriction is an oil log or a restriction.
id say first try and defrost it. If that doesnt work. Add a little propane, the p/t of propane is about the same as r-22, the draw back is that it is flamable. So be careful!

i dont know the cost of the propane. im a worker b and dont pay the bills, cant be to much $

or evacuate and get 250 psi nitrogen and try shovin out your restriction.


I doubt all that work is cost efective, but i thought id give you some options

some restrictions on domestic units, can mean a dead unit.

[Gary]

R134 systems use POE oil. This is wonderful stuff, but it has a serious flaw:

POE is a very effective solvent. It cleans the inside of your system like nothing else can. Thats the good news. The bad news is that it deposits all of that gunk in the drier, which can cause a restriction.

[cpt. cascade]

If you got enough gunk in your system to block the drier, then your not doin your job. clean that sucker! in cascade systems after a nice soothing flush, we do a nitrogen pressure test 250psi. after that we must atain at least 50 microns. i can eat outa my systems. god i love my job

[angryk]

Most POE oil cap tube restictions I come across are on sealed units. By sealed, I mean the way they come from the manufacturer, with no service access. I suppose it can be said that the manufacturer did not use proper methods upon manufacture, but the sheer number of restrictions that occur is enough for me to rule out that possibility. High heat is definitly the cause on most I come across, i.e. dirty condenser. I am really suspicious of those copper spun drier that are OEM installed, they really like to clog up solid, I don't feel they are up to the task of being on a POE oil system. Sometimes you may be able to get away with just replacing the drier. I really like sporlan's C-032 CAP/T drier, I've had excellent success with them. That being said, Can anyone enlighten me on what actually clogs the drier and cap tube. I've heard some say wax, could that be the insulation from the compressor windings breaking down? I've also heard somthing about the drier itself breaking down. Comments?

[cpt. cascade]

burnt, nasty oil is what i was always told. like cookin down vegtable oil to vasaline . I do agree with you on most of what ya said, exept, i prefer 052s driers. oh and question: on hh driers, your not suposed to leave those little guys on are you?

ive been doin this since i was 12 so i forgot alot.

[Prof Sporlan]

I really like sporlan's C-032 CAP/T drier, I've had excellent success with them.

Need the Prof say more?

That being said, Can anyone enlighten me on what actually clogs the drier and cap tube.

Sludge and varnish, from oil breakdown, dirt, oxide, flux, metallic particles, and other unspeakable organic and inorganic matter present in the refrigeration system just waiting to collect at the expansion device...

POE oil, as Gary previously notes, is perhaps the finest solvent the refrigeration industry has ever seen, and it will do an exceptional job of cleaning the insides of a refrigeration unit and depositing the debris... somewhere...

I've heard some say wax, could that be the insulation from the compressor windings breaking down?

Wax is a funny thing, and not completely understood, though it tends to be more of a problem with certain refrigerants and oils. R-502 low temp systems were particularly susceptible to wax problems, and it occasionally showed up with R-22 refrigeration systems. Wax can come from other sources, however. Process fluids used in making tubing and refrigeration components are also suspect. Sporlan developed the "HH" core to address problems of wax.

I've also heard something about the drier itself breaking down.

It is possible for any filter-drier to break down if the chemistry in the system is sufficiently bad. For example, a very high acid condition can overwhelm and break down a drier. Here, you are better off with a core type filter-drier, such as the C-032-CAP-T where you have a greater desiccant mass and a binder to keep things together than you have with a loose fill drier.

[angryk]

Thanks prof.. As always you are very helpful. Cascade- The only filter/driers not to be permanently left in a sysyem are on the suction side.

[frank]

John K

This is from the Copeland link that Herefishy posted - seems like you can leave a suction drier in place after all

Q20. Should a suction line filter drier be installed before or after an accumulator?
ANSWER: A drier is designed to be a temporary device to clean a system after a burnout. The suction line acts like a chimney during the burn and the soot carries into the accumulator. The soot will need to be caught before entering a newly installed compressor. For this reason we suggest that the drier be installed between the compressor and the accumulator. It should be removed within 48 hours and replaced until the system is cleaned and acid free. At this time it may be removed or a filter left in place. The filter may be installed up stream of the accumulator to keep the accumulator from being contaminated.

[Andy]

Hi,
when building compressor packs in the past I have tended to fit danfoss filter housings, the ones used on the liquid line with removable suction felt cores or mesh filters. After a burnout, just fit a burnout core and run until an apreciable pressure drop occurs, then replace and keep replacing until the pressure drop is as per a new core.
Regards, Andy

[cpt. cascade]

The reason i ask is because one of my co-workers was trying to tell me that HH driers should only be used temporaraly. I had been useing hh driers on all my bunouts. Now i just flush the heck out of em, and hope my 052 does the job. So is he just totally wrong?


I also had another question. As i have mentioned before oil loging is a big problem for cascade systems. Often we will have a unit at temp (-80), when we move the freezer to another location and plug it in, the unit oil logs. I think it might have something to do with the migration of the refrigerant and oil caused by the pressure differences. Any thoughts on a solution?
Do you think mounting an oil strainer directly over the oil seperator's outlet might help? As the pressure would flow it would have to go through the strainer, catching oil and returning it to the oil sep via gravity. would that pose to much of a restriction on my system? Am i just bangin my head on a wall? What do you guys think?

Thanks guys, great forum

[Dave Goodings]

Alright Capt
I would be asking the question what type of oil seperators are you using as the new coalescer filter/seperators remove a lot more of the oil that would circulate in the system, I know a few of the pack manufacturers are using these for oil seperation with a good success rate so they may be worth considering one of the guys may have more details on these
Regards Dave

[Prof Sporlan]

The reason i ask is because one of my co-workers was trying to tell me that HH driers should only be used temporaraly.

It's standard practice to replace "HH" driers used in the suction line to clean up a system following a burnout. Suction filters as opposed to filter-driers are better suited for permanent suction line service.

A filter-drier with the "HH" core, or for that matter, any filter-drier may be left in the liquid line permanently, provided it is not taking excessive pressure drop, and has available water and acid capacity.

[cpt. cascade]

temprite 900 series. sorry about typo

[adacus1]

I work on larger than domestic systems but have found that one of the quickest ways to plug a system is to use cheap filter/driers. The tendency is always for the dessicant to leach into the system. Use a solid core drier always, I prefer the Sporlan C164.

On R134a systems with any significant mineral oil content - There shouldnt be any - then mineral oil breakdown can create a sludge in the system

[Gary]

Use a solid core drier always, I prefer the Sporlan C164.

What do you have against the Sporlan C165, or the C084. or the C304S, etc.?

[adacus1]

It fits it works and has always worked in the systems I work on

[adacus1]

Yes I use others so should have said use Sporlan Catch-all as they have never let me down in any way.

Yes I use C304 / 305 on larger systems and use the 304 on smaller systems when changing burnt out compressors and need to clean the system. bigger capacity use one size larger filter / drier.

[john squibb]

whAT ON EARTH ARE YOU GUYS TALKING ABOUT i only asked how do you go about clearing a blockage in a domestic refrigerator
im in england and only service dom ref.
when i havea blockage i cantgo any futher but would like to.
i have heard about a bottle jack type device to pump out the blockage
but where from & how do you connect it

i use the lokring system as i work with r600a
i asume you would connect apressure device to the free end of the capilary tube and pump for england

please help you techno wizards but go easy on the lingo !

john

[condenseddave]

I have a pump made by a company called Thermal Engineering Company.

The thing comes as a kit, with a selection of lead wires sized to fit inside of cap tubes.

The pump, which looks like a small bottle jack, is filled with refrigeration oil, and connected to the end of the cap tube.

The pump thens pressure cleans the cap tube. The lead "chasers" are optional, but very effective.

They fall into the evap and stay put after the cleaning is done. I have never seen any adverse system reactions to this, but I only use the lead wire when the pump cannot unblock the cap alone.

The link to the kit:

http://www.thermal-eng.com/HTML/5101.htm


Here is their homepage:

http://www.thermal-eng.com


I've had this thing for years, and didn't really use it all that much until about a year after POE hit the scene.

It is really a useful tool to have. I wouldn't put one on every truck, but I don't do a lot of systems that size anymore. I run across the clogged caps on the small 404a under counter freezers quite a bit.

I'll also echo the sentiments of those who like the C-032-CAPT driers (and the 052,s...) for these systems. They are the greatest.

[Tejbir Singh]

we clean the caps by using the nitrogen straight from cylinder with out any regulators as this will give us a pressure of around 1500-2000 psig which is sufficent to clean any sludge oil from the caps but remember to free both ens of the cap free to reduce any risk of accidents which normally burst the evaporator

[nike123]

we clean the caps by using the nitrogen straight from cylinder with out any regulators as this will give us a pressure of around 1500-2000 psig which is sufficent to clean any sludge oil from the caps but remember to free both ens of the cap free to reduce any risk of accidents which normally burst the evaporator

And how you connect capillary to nitrogen cylinder in safe manner?

[lowcool]

suicidal tendency i think nike,could just imagine a capillary flailing around madly

[Sledge]

Is there literature explaining clearly sizing and application of filters and driers. How does one know if there is remaining capapcity in a filter drier for acid and moisture. In the past I have just left the thing in unless there is a fault.

[kiwireeferman]

whAT ON EARTH ARE YOU GUYS TALKING ABOUT i only asked how do you go about clearing a blockage in a domestic refrigerator
im in england and only service dom ref.
when i havea blockage i cantgo any futher but would like to.
i have heard about a bottle jack type device to pump out the blockage
but where from & how do you connect it

i use the lokring system as i work with r600a
i asume you would connect apressure device to the free end of the capilary tube and pump for england

please help you techno wizards but go easy on the lingo !

john

Turn off power, wait a couple of minutes. use a proper cappillary cutter to cut the cappillary tube about 20mm from the dryer oulet.
If you have liquid exiting the dryer your problem is the tube itself. If no liquid then the dryer is choked.
If it's the tube remove suction from compressor and wack in about 100ml of solvent (RX11 or similar) with around 300psi of nitrogen. Put the free end of the cappillary into a container to catch the crap. It may need to be left for a day or so for the solvent to disolve the gunk.
When it starts to come through put your finger over the end of the cappillary, on and off to give a pulsing action.
As you have captured the solvent exiting, you have a good idea if you have got out what you put in.
Flush till the solvent is clear. Good luck.

[lowcool]

300psi their goes the cooling plate,cut the capillary for refrigerant flow,im not one to procrastinate but it would not hurt one to supposedly help the enviroment.just in case.
sorry i see the 300 psi is free flowing.
cheers