propor vacuum technique....

[primmers]

since finding this site, i have learned a bunch...thanks to all..

my question now is..propor vacuuming..i have just used a pump for a hour and then went for it..im reading this is not the case..
i have done a search, but havent found what im looking for..id like to read a step by step procedure...also a recommended micron guage..also how does nitrogen help in the vacuum process..

[R12rules]

Yellow Jacket micron gage, cost about $275 but well worth it.

Pull down to 1000 or 500 microns and let it hold with gages blanked off.
Remove your schrader valve cores prior to the start of work.
Nitrogen acts as a blotter to absord moisture which might be present inside the sealed system.

I believe in TRIPPLE EVACUATION.

Pull down to2500 microns, break with nitrogen then repeat two more times. On the third time, continue evacuation until either 1000 or 500 microns are reached.
But I would certainly NOT go lower than 500.
Mineral oil inside the comprewssor begins to vaporize, (boil off), @ 275 microns.


If you evacuate with schrader valve cores still in place, you are being lazy.
If you do not practice tripple evacuation, you are not educated in this field properly.
And if you do not use a high quality micron gage when ever you use your vacuum pump ... you are simply a shade tree drunkard who poses as a technician.


Oh ... and you need to change your vacuum pump oil often.
Sometimes even more than once during an evacuation process.

Oil gets wet from what it is pulling out from within the sealed system. Wet oil inside the vacuum pump will NOT provide satisfactory results.


I didnt make up the rules ... we just live by them.


When ever you have a really wet system, you will need to employ a chill chamber in order to attract the moisture to the walls of the chill chamber BEFORE this moisture reaches the vacuum pump.

Use a four valve manifold set. Like Brute or Imperial.
Use braided stainless lines or copper lines so you dont have seepage in your hoses.

Charging hoses are not completely air tight. Even the best of them, which are the black charging hoses.


Evacuate using a 3/8" or better, center port hose. Never waste your time using a three hose/ two valve charging manifold to evacuate and recharge a sealed system.
It is very unprofessional indeed.



Now if this post dont stirr up some creative writting ... I dont know what will.



There are more ol' wives tales about this particular aspect of service practice than almost any other part of our trade.



non-condensibles & micron removal
http://hvac-talk.com/vbb/showthread.php?threadid=66819

[Edited by R12rules on 07-09-2005 at 06:05 PM]

[primmers]

god i hate being lazy and a shadetree drunk...

but i printed your reply and will forever change my ways..

garcia..

[shogun8]

The object of reducing the pressure in a system to a deep vacuum, known as pulling a vacuum, is to remove vapor from the system. It is measured in microns. Many manufacturers will say in their specifications that they want you to pull a vacuum to 250 or 500 microns and hold that pressure for a time span to prove there are no foreign vapors in the system. This would include water vapor. A pressure reading of 500 microns is actually 1/2 of a millimeter and cannot be readily detected with the naked eye with a column of Hg.” When the vacuum pump manufacturers say this, they mean in a clean system with nothing that can boil to a vapor. This will not work in a refrigeration system because we have oil in the compressor and piping that will emit small amounts of vapor. So listen to the teacher!

[igwt777]

R12rules

Very nice concentrated procedure. You covered all.

[Dad]

12...

you get bored again?

A nice job there.


Hey... where are my winnings?

[primmers]

while were on the topic, i work at 4000' and above
is there a chart for the 500 micron to hg to compensate for altitude?

[igwt777]

Originally posted by primmers
while were on the topic, i work at 4000' and above
is there a chart for the 500 micron to hg to compensate for altitude?

I hope this help!!

http://www.hyvac.com/tech_support/At...essure%202.htm

http://www.hyvac.com/PDFs/Literature...uct%20List.PDF

[R12rules]

Originally posted by lusker
12...

you get bored again?

A nice job there.


Hey... where are my winnings?

Thank you Dave for the kind words. Are you telling me you have not received your prize for the Chicken Soup award?

Hmmmmm.... I will make contact with the ebay seller whom I bought your Gerber thru.

Sorry you have had to wait.

[R12rules]

Originally posted by primmers
god i hate being lazy and a shadetree drunk...

but i printed your reply and will forever change my ways..

garcia..

That's funny.

Trouble is, a lot of us just get lazy when it comes right down to doing things the way we were taught.
Whenever we take short cuts, they will come back to bite us.
There are no winners when it comes to cutting a proceedure short. Only losers.


You also have to remember .... there are no perfect techs!
Some are great when it comes to troubleshooting.
Others do their best work in mechanical situations.
Some are best with electrical stuff.


But here in this forum community, we can all share what the best of the best have to offer.

[Dad]

Bob.. no soup for you!

Na.. it hasn't shown up as of yet.

Thanks.

[primmers]

well, i maybe the ..exception here, i worked for the buisness i now own for 2 years, working with a guy that went to refrigeration school and ran his dads buisness..
then the dad wanted to retire..offered the refrigeration thing to his son(who i worked under)...he didnt want it, it was offered to me..what was i gona do? i bought it, being only certified..i worked it for a few more years, and my daughter who was in insurance talked me into getting my licence..i also while working for the buisness as a employee did a school through the mail andcomputer...i learned nothing there...
i have only one competitor up here..and he has helped me out...but this site is a god's sent..
i hope you all will bear with me..

[Dad]

Primmers...

Now that we know the truth about you... we must convene the membership board to see if you quality to be here. If the board sanctions it we must go forward with your immediate expulsion and label you a danger to yourself....

























Seriously... welcome to the site and I hope we can live up to your expectations.


BTW, fill out your profile.