if you only pull 500 microns of vacuum for your customer, you are not
getting all of the water out and are going to be making hydrochloric acid
for them, so they can buy a new unit from you, Mr. Con Artist.
quit ripping off the customer and change your pump oil or buy a new pump and
start pumping with good enough equipment, and for a long enough time, to get
down to 50 - 75 microns for an hour.
if you don't understand what the oil has to do with the final amount of
vacuum, or don't understand what are "microns" or don't have a precision way
to measure them, PLEASE RETIRE, because YOU SUCK, you INCOMPETENT HACK
-----BEGIN PGP SIGNED MESSAGE-----
Bull feathers. If you are making acid, it's because you are a hack,
but for different reasons: No nitrogen while brazing, no drier
no vacuum pump can purge all the acid without an oil change and
flush, once contamination of "burnt freon" has taken place.
Why do you think, back in the old days, some techs used to flush the
lines with R11, R13 or dichloromethane, after a hermetic burnout?
With a single-stage vacuum pump, a good idea is to triple evacuate,
-----BEGIN PGP SIGNATURE-----
Version: PGP 7.1
-----END PGP SIGNATURE-----
Answer one question
on how many units did you work that do run at
-85 degrees Fahrenheit and must make -100
yes you can use R-11, R-114 and few others
but field person must use what is readily available
and don't come telling people what is in book
but from your own experience work done.
ANYTHING I POST I HAVE ALREADY DONE IT
I do not IMAGINE IT I did it
I suggest not only to you but to any that read this
get some books on ultra low temperature and start
reading before you come back to me
with some stupid answers that you have no idea
of what the heck you are talking about it is bloody disgrace
that some of you. servicing air conditioners and nothing ales
as long as you being doing this and you think you are expert
on refrigeration, with answers and posting you gave
if I was to gave you to clean my bathroom I strongly believe
that my bathroom would be insulted,
and Johnny this does not only pretend to you.
You have big company
don't new a/c installs have to be evacuated to 300 microns? in
automotive we use 600 microns, but we also use 0-rings instead of
I'd really like to see the vaccuum pump that will pull it to 50
" in automotive we use 600 microns"
WHAT KIND OF BULLSHIT "MECHANIC" ARE YOU??
I am in automotive A/C, and we use 50-75 microns vacuum, if you use 600 then
you are screwing your customers, and blaming O-rings for your insufficient
vacuum is ridiculous, what the hell do you think the seals your manifold
gauge set, hoses, and all other equipment are made up of?
you need to be in the special olympics, rather than working on automotive
A/C, you stupid retard hack
Most manufacturers installation instructions say evacuate to 350
microns, then insure that the vacuum holds for at least a minute after
closing off the vacuum pump. Their instructions (and their warranty)
are good enough for me.
I do not want blow you bobble however I think
that you are depending far to much on micron gauge
am I? nut no I am not I have been doing refrigeration work
guess? for over 40 years and field work since 1969
first good mechanic must visualized ( presume lost of gas)
how refrigerant was lost if is on high side or low side
if is on high side take in consideration what it will take to
fix the leak or problem and go from there on, it could
need just half hour or couple hours that determine how long
you will keep system open and to get it fix.
Low side leak again examined problem was the unit running
with no refrigerant in the system or did unit shut down on safety
how long was it with out any refrigerant in it, all this things
must be taken in consideration, only then you can
decide how long you will need to have it on vacuum
low side could be from hour to overnight and more if it
happen that solid water got into system, first you must
purge it with nitrogen (GN2) try to blow out all water as
possible then and only then put it on vacuum.
Now micron gauge With reading on the gauge
of 100 MICRONS YOU CAN STILL HAVE WATER
IN THE SYSTEM? impossible I have news for you
It is possible! how? well while water boils at low pressures
but it ALSO FREEZES and once it get frozen it does not
boils any more. Procedure is to pump system down
for couple hours then purge the system with GN2
let it sit for hour with GN2 in it then put on vacuum again
this procedure you may have to do few times depend
on size of the unit it self. I would also recommend changing
of oil "filter drier must" open and clean oil separator if there
is one plus add oil filter on return line On POE system
oil change is must and do not put clean oil in until
you have evacuated system first.
and no you are not boiling oil out what you see is oil bubbling
you are taken out residue of gas and moisture
Good luck Dido say that
Frozen water changes directly from the solid into the vapor phase under low
pressure conditions, due to a phenomena known as 'sublimation'.....IOW, no
"boiling" is needed.
Well, I spose it was rather unrealistic of me to expect an illiterate
fuckwit such as yourself to actually comprehend much if any of the
information contained within the link I posted, and I guess I might be one
of only a few that actually paid much attention in 9th grade science
Still, appreciate if you don't send me anymore email on the topic.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.