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Thread: Leakage check

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    Leakage check



    Hi

    I just installed a mini SPLIT system pipes and I am about to vacuum it.

    As I don't have nitrogen I applyed air with a small air compressor the type we use to tires.
    ( using a refrigeration filter in-line).

    I spread soap and saw some bubbles on connection.

    I tightened the connection and saw no bubbles anymore.

    The manometer read 87 PSI for 30 minutes and then drop to 84PSI.

    1- If there is not bubble anymore at 87PSI, can I make sure there is not leakage ?

    2- What is the better choice to flare a tube ? at minimum or maximum

    I did it at minimum possible, almost even with the flare tool surface.
    I notice when I do it too large the nut seems very hard to tighten.

    Moises



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    Re: Leakage check

    get a fridgie to do the install- pressure test on a r410a system is around 40 bar, 28 bar with 407c/r22 systems- your air compressor will cut out at 10 bar!- buy nitrogen- oxygen free

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    Re: Leakage check

    Quote Originally Posted by install monkey View Post
    get a fridgie to do the install- pressure test on a r410a system is around 40 bar, 28 bar with 407c/r22 systems- your air compressor will cut out at 10 bar!- buy nitrogen- oxygen free

    This equipment is an experiment. I can reinstall it over and over if necessary.

    I think if I become practical at doing the flare I will have not to worry so much with accurate leakage test at least in small units.

    Please give me opinions.

    At the point it is, can I check possible leakages in vacuum with some chances of succeed ?

    Which is the best option to flare, large or small length of tip the pipe at the flare tool surface ?
    Last edited by Acrisoft; 20-12-2012 at 11:04 AM.

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    Re: Leakage check

    .

    Hello Moises.

    You are playing at what most on here, consider as our chosen
    profession and you are asking us to give you advice on doing things
    that are actually illegal in Europe.

    Pumping low pressure air into an AC system is everything we are taught
    not to do and yes we are taught. We have to go to college and learn for
    years and we work with more experienced engineers for years learning our
    trade and then we have to take expensive exams to prove we are competent
    to do the work.

    What you are doing, as much as I understand your eagerness is wrong by
    our standards and if we were to do it we could get into serious legal trouble.

    So please don't be offended if we refuse to give you advice, when what you
    are doing is breaking all the rules we stand by.

    Regards

    Rob

    .

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    Re: Leakage check

    Thank you Rob. Your right.
    But I was just testing an equipment that belongs to me. I will buy nitrogen soon.

    I was only trying to find de ideal size of the flare, because I saw many techs doing it in different ways.

    I know air may contain an considerable amount of moisture.

    Moises

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    Re: Leakage check

    1 meter.

    Good luck.


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    Re: Leakage check

    Brian - Newton Abbot, Devon, UK
    Retired March 2015

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    Re: Leakage check

    Quote Originally Posted by Rob White View Post
    .

    Hello Moises.

    You are playing at what most on here, consider as our chosen
    profession and you are asking us to give you advice on doing things
    that are actually illegal in Europe.

    Pumping low pressure air into an AC system is everything we are taught
    not to do and yes we are taught. We have to go to college and learn for
    years and we work with more experienced engineers for years learning our
    trade and then we have to take expensive exams to prove we are competent
    to do the work.

    What you are doing, as much as I understand your eagerness is wrong by
    our standards and if we were to do it we could get into serious legal trouble.

    So please don't be offended if we refuse to give you advice, when what you
    are doing is breaking all the rules we stand by.

    Regards

    Rob

    .
    Well written, well stated and not offencive.
    In fact you have reminded us all Rob that in our eagerness to help and advise. We sometimes forget just how many years "WE ALL" have to slog to attain said knowledge.

    Moises good luck,

    Grizzly

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    Re: Leakage check

    Hi Moises
    Keep up the good work. Your steps for self learning can be commended and as you yourself have identified the steps and improvements you require to successfully accomplish your goal, this is the very best learning available. When you vacuum and get down to 2 Torr or less you will know your system is leak tight and its far less risky than high pressures.

    Its not the see and do approach, its not the formal learning approach geared to passing the exams for a "fee"
    You can flare and pressure test with your air comp to your hearts content and you have not broken any law I can see. When refrigerant is released into the system we get into some grey areas but as you are not doing this for profit. I do not see anyone ever being able to prosecute. In the UK anyone can walk into a automobile wholesaler or internet and buy refrigerant gas for their car ac or even any other requirement. I do not see the pickets protesting outside Halfords!!

    Until the supply of refrigerant is policed and controlled there will always be a grey market. If we do not experiment we do not learn as human beings and most of our progressive developments were done by people being told they will never succeed and they should not be doing it!

    I think Bob may have to monitor some of his bodily gas discharges for Global warming potential!
    Last edited by hookster; 21-12-2012 at 07:09 AM.
    I love the smell of Ammonia in the morning!

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    Re: Leakage check

    Quote Originally Posted by hookster View Post

    I think Bob may have to monitor some of his bodily gas discharges for Global warming potential!
    Gas discharges, me, spouting hot air



    Regards

    Rob

    .

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    Re: Leakage check

    Quote Originally Posted by hookster View Post
    Hi Moises
    [snip]When you vacuum and get down to 2 Torr or less you will know your system is leak tight and its far less risky than high pressures. [snip]
    Remember that a leak test under a good vacuum is a form of reverse pressure test to 1 bar, 14.7psi, only; not much of a test really.

    A pressure test does need to be made under a positive pressure.
    Brian - Newton Abbot, Devon, UK
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    Re: Leakage check

    Not to mention all the various leaks that can be sucked tight but leak under positive pressure...


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    Re: Leakage check

    in Australia asoon as you let that gas into the system you are looking at a 10,000 dollar fine.

    Due to the fact that if you have a small leak that you couldnt pick up with your low pressure test and your whole charge of gas leaks to our already patchy ozone . you might aswell have run 10 cars all year with the amount of damage it does. < figures are just a guess >

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    Re: Leakage check

    Quote Originally Posted by Simeonx1 View Post
    in Australia asoon as you let that gas into the system you are looking at a 10,000 dollar fine.
    Which is itself insane. In my use of electronics freezer spray, I release more r134a into the atmosphere every year than would be in my car AC. Having said that, the freezer spray is a cheapest way of getting 134a for my car AC

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    Re: Leakage check

    Quote Originally Posted by Simeonx1 View Post
    in Australia asoon as you let that gas into the system you are looking at a 10,000 dollar fine.

    Due to the fact that if you have a small leak that you couldnt pick up with your low pressure test and your whole charge of gas leaks to our already patchy ozone . you might aswell have run 10 cars all year with the amount of damage it does. < figures are just a guess >
    Were only doing it for our own conscience.
    China is pumping out R22 etc like there is no tommorrow.

    You can still buy a split at Bunnings, go figure!

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    Re: Leakage check

    .

    Where do you think the majority of the gas goes?

    Copied from
    Technical Support Organisation RA EMA Technical Information

    "Although there are some difficulties in substituting HCFCs, they are challenges both the Chinese
    government and the AC Industry must face. China is the largest AC manufacturing base in the
    world. The AC industry in China uses 70,000 to 80,000 metric tons of R22 each year. As companies
    with a strong sense of responsibility, many of the Chinese room AC manufacturers would like to
    become pioneers in substituting R 22."


    In rich Countries like ours and yours there is a lot of misunderstanding
    regarding the control and release of refrigerants in Countries like China
    and India.

    We are a bit hypocritical living in our air-conditioned ivory towers looking down
    on other nations because they want the same life style as us.

    China my be one of the largest contributors of waste emissions into the atmosphere
    but where do you think the majority of all the produce ends up. It ends up in Countries
    like mine and yours.

    If I cleared my house of all the Chinese made products (especially TV's, PC's and fridges)
    I would have nothing left.

    It's a bit hypocritical of us to call China when all they are doing is making the stuff we want
    for cheap.....

    Regards

    Rob

    .

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    Re: Leakage check

    If I cleared my house of all the Chinese made products (especially TV's, PC's and fridges)
    I would have nothing left.
    This statement is true but a bit naive, we, by buying this cheap stuff, have destroyed most of our industries in favor of the Chinese.

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    Re: Leakage check

    Quote Originally Posted by chemi-cool View Post
    This statement is true but a bit naive, we, by buying this cheap stuff, have destroyed most of our industries in favor of the Chinese.
    No not Naive, that was my point.

    We have systematically reduced our ability to produce anything and
    on the back of that we now have a reduction in our pollution levels,
    but we still want to watch TV on 40" plasma screens, driving air-conditioned
    cars along nice tarmacked roads to AC controlled offices and other work areas.

    We then like to relax sipping cold larger and eating food and nibbles sourced
    at the lowest price (despite the effect on farming) that has been sold by a select
    few supermarkets.

    We all use mobile communications that are built in part from rare and hard to source
    commodities that when they are less than a few years old, we discard for the next new
    version at even cheaper cost.

    And we look down on the Chinese and Indians because they want to do the same.....

    Rob

    .

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    Re: Leakage check

    Easy Boys!
    We all are more than a little hypocritical in some topic.
    However we can all help as well.
    I hate most new regulations, however they soon become the norm.
    Who remembers when compulsory Helmets for motorbikes became law?
    Or the compulsory wearing of a seat belt?
    I even strap in loose boxes or data files which on my back seat now, All without questioning.
    How about.
    Drink driving!
    Recovering gas, Venting to atmosphere. anti flash back valves.
    Dedicated valves and special regulators.
    I suspect I have missed loads.

    If you had canvassed me when any were being introduced. I would of seen red.

    I cannot as you say criticise any for I have been there too!

    Cheers guys!
    Last edited by Grizzly; 22-12-2012 at 02:48 PM.

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    Re: Leakage check

    Quote Originally Posted by Grizzly View Post
    Easy Boys!
    We all are more than a little hypocritical in some topic.
    However we can all help as well.
    I hate most new regulations, however they soon become the norm.
    Who remembers when compulsory Helmets for motorbikes became law?
    Or the compulsory wearing of a seat belt?
    I even strap in loose boxes or data files which on my back seat now, All without questioning.
    How about.
    Drink driving!
    Recovering gas, Venting to atmosphere. anti flash back valves.
    Dedicated valves and special regulators.
    I suspect I have missed loads.

    If you had canvassed me when any were being introduced. I would of seen red.

    I cannot as you say criticise any for I have been there too!

    Cheers guys!
    it will soon be an offense to fart in public the way things are going

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    Re: Leakage check

    Well that's me buggered!

    Yeah!
    It does feel like that sometimes.
    Hey Life is not fair, is it!

    Nice to see you with us Quality.
    Grizzly

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    Re: Leakage check

    .

    I've already been accused of venting too much.

    He must know me

    Rob

    .

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    Re: Leakage check

    It is far safer to recommend a vacuum holding test than a high pressure test to the untrained. If in the written example he had already tested to 6 bar with a compressor then carried out a 2 Torr holding test. It is from all practical experience guaranteed that this work would be leak free.

    Christmas always brings out the best in my release of my own stored GWP gas! I blame the Brussel Sprouts!!
    I love the smell of Ammonia in the morning!

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    Re: Leakage check

    Hi

    I was a fridge repair man in the past and also electronic technician.

    But high pressure systems seem very different and dangerous for me.

    I finally installed the SPLIT AC and it's working.

    I have two AC in my apartment now.

    The first one the tech installed without pressure test.

    I pressure tested mine with 120PSI air compressed although I know it is not enough and then vacuum it for 2 hours.

    I imagine if a guy ( as the tech) is able to do a very nice flaring he will not have to worry too much about leakage in mini SPLITS.

    But I my case ( self study) if manifold remains between 29" to 30" hg in manometer
    can I roughly say there is not leakage ?

    I mean: would even a very small leakage cause the pressure to raise form something
    as 25" hg in a couple of minutes after the vacuum pump is turned OFF ?


    Moises


    Quote Originally Posted by hookster View Post
    It is far safer to recommend a vacuum holding test than a high pressure test to the untrained. If in the written example he had already tested to 6 bar with a compressor then carried out a 2 Torr holding test. It is from all practical experience guaranteed that this work would be leak free.

    Christmas always brings out the best in my release of my own stored GWP gas! I blame the Brussel Sprouts!!
    Last edited by Acrisoft; 29-12-2012 at 06:03 PM.

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    Re: Leakage check

    Here's an example of what happens without proper testing.

    I recently repaired a mini fridge that had it's evaporator ice picked. I replaced the evapoator because it was a cheaper option than repairing in this case so I had every joint to resolder. I did a 120# nitrogen test for about an hour and after vacuuming I let it sit for about a half hour. I put 2.2 ounces of R134A and fired it up. All systems go. I returned it to it's owner and in about a week I got a call that the beer was warm. I made a house call and found that the charge was low.

    I got lucky and found the leak with bubbles. It was on a new bullet drier with service valve. The leak was where the two tubes went into the end of the drier. I replaced that drier and welded the ends shut on the leaker and pressured it with 120# nitrogen. That was four days ago. I'm now down to 25#.

    The point being that this tiny leak was on the high side that can get up to 200#. It took over a week to lose enough of the charge to affect the cooling. A short pressure and vacuum test didn't find it but I might have found it with bubbles had I thought to test the factory welds(epoxy?) too.

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