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Thread: Micron gauge and vac loss
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23-04-2010, 01:58 PM #1
Micron gauge and vac loss
I need some advice if possible please. I am installing a few small splits and purchased a vacuum gauge recently a vg64 supco. Previously i bought and used a refco digimon gauge set and hoses. However on using it to install a small split the lowest it would indicate was -930mbar or about 95% vacuum. Below this the unit does not indicate the absolute vacuum. What a load of rubbish what is the point?
Anyway for the remaining splits i bought the vg64. I have decided to bench test it so that i can get and maintain a vacuum prior to connected it to the split line sets.
So getting to the point, i have the vg64 connected to the digimon via the low line and the hi closed and then the yellow hose connected to the vacuum pump (a cc31)
After vacuuming for 20 minutes and getting down to below 250, i close the low tap on the digimon isolating the line to the vg64, i have a leak as the microns slowly increase to over 2000 over 30 or 40 minutes, i have improved the situation by putting some vacuum oil on the hose couplers and tightening. However the microns still increase. Is it possible for the hoses to be leaking, i have tried swapping with the spare hoses in the digimon kit but its the same.
Could the REFCO hoses be outgassing???
Also supco advises to use copper hoses as service hoses and for coupling the vacuum pump to the system as they say that it is unlikely rubber hoses will hold a vacuum. Please help me as im pulling my hair out at this point!
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23-04-2010, 01:58 PM #2
Re: Micron gauge and vac loss
Also how tight should the couplers be on the hoses should they be hand tightened or some kind of vice grip used gently? Thanks
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23-04-2010, 05:34 PM #3
Re: Micron gauge and vac loss
After some testing and a process of elimination i think the digimon gauges are leaking slightly on the valves. Is this for real? I shall be purchasing a ball valve shut off on Monday and isolate the outdoor unit, a hose, the vacuum pump and a ball valve.
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23-04-2010, 11:03 PM #4
Re: Micron gauge and vac loss
Can anyone tell me so i can ponder it over the weekend if i need a good set of rubber charge hoses to hold a vacuum like yellow jacket etc or will a normal set of refco hoses hold a micron rating. If so why does supco recommend against ordinary hoses?
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24-04-2010, 08:57 AM #5
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24-04-2010, 09:00 AM #6
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Re: Micron gauge and vac loss
Ordinary hoses are designed for positive pressures and they are not suitable for vacuum job.
Find something like this:
http://www.appioninc.com/products/mgakitfeatures.html
http://www.appioninc.com/products/cat-tools.html
Put isolation valve and Supco vacuummeter directly on system. After evacuation is done to acceptable level, isolate system from hoses and vacuum pump and watch for pressure rise.Last edited by nike123; 24-04-2010 at 09:05 AM.
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24-04-2010, 09:26 AM #7
Re: Micron gauge and vac loss
Im in Ireland so may be tricky getting those lines. I can get yellow jacket plus 2 hoses with ball valves but it doesnt say anything on their web site about being vacuum certified.
If i purchase a ball valve isolation and 2 flare nuts for 1/4 inch refrigeration copper can i connect the service port of the outside unit to the micron gauge 1/4 sae with 1/4 liquid line and the isolation valve on the other vacuum port and then the service hoses to the digimon etc.
And yes the digimon looks like a kids toy
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24-04-2010, 09:30 AM #8
Re: Micron gauge and vac loss
The other option is to buy this http://www.amazon.com/Yellow-Jacket-.../dp/B0014JDNVO
The angled one and attach the vacuum gauge to the angle off connection
How does this item connect to the outdoor valve is it just a twist on connection, and how does it attach to the service hoses? Does one have to remove the shrader core i dont want to mess with that just to save a few minutes vacuuming.
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24-04-2010, 09:54 AM #9
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Re: Micron gauge and vac loss
Last edited by nike123; 24-04-2010 at 10:20 AM.
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24-04-2010, 09:56 AM #10
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Re: Micron gauge and vac loss
It is not few minutes, it is more than 30% faster than with cores.
http://www.youtube.com/watch?v=VWyUj9BO0U4Last edited by nike123; 24-04-2010 at 10:15 AM.
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24-04-2010, 10:09 AM #11
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Re: Micron gauge and vac loss
If you are speaking of instalation of single split system and vacuuming it, than it is not economical to make vacuum leak test since it is taking time from 1/2 hour to 1 hour to confirm leak.
Just bring vacuum to 500 microns and hold there or below 10-15 min, isolate micron gauge and then release refrigerant in pipes and indoor unit until 0,5bar is on gauges. Remove gauges open service valves fully and put cap on. Switch unit to heating and check for leaks with soap bubbles at flares and valve caps. You don't need to monitor pressures since pressure alone will not tell you anything except that you have gas inside or not.Last edited by nike123; 24-04-2010 at 10:28 AM.
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24-04-2010, 11:03 AM #12
Re: Micron gauge and vac loss
Im doing my own splits so time isnt too much of a problem
The youtube link is very interesting and makes sense.So if i buy the valve core tool to attach the vg64 vac gauge to it needs 2 1/4 inch flare nuts and some 1/4 copper liquid line yes? Do i definately have to remove the valve core or does that tool operate the shrader valve? If need be i will remove the shrader core.
Local distributors stock the valve tool and some isolation valves so i might try that first rather than order some expensive hoses from the isle of wight.
The other option is connect the units service valve to the vacuum gauge with 2 x1/4 flare nuts and some liquid line and into the other port attach an isolation valve and then the digimon to that . I know this is slower to vacuum but will it work?
1/4 inch flare nuts that attach to 1/4 inch copper fit 1/4 inch sae flare males on vacuum gauges yes? Thanks for all the help
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24-04-2010, 11:20 AM #13
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Re: Micron gauge and vac loss
It does not operate shrader valve. You need to remove valve core.
Local distributors stock the valve tool and some isolation valves so i might try that first rather than order some expensive hoses from the isle of wight.
The other option is connect the units service valve to the vacuum gauge with 2 x1/4 flare nuts and some liquid line and into the other port attach an isolation valve and then the digimon to that . I know this is slower to vacuum but will it work?
1/4 inch flare nuts that attach to 1/4 inch copper fit 1/4 inch sae flare males on vacuum gauges yes?
It appears that vacuum tight certified hose is must or you need some adapter on VG64Last edited by nike123; 24-04-2010 at 11:23 AM.
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24-04-2010, 12:02 PM #14
Re: Micron gauge and vac loss
As homer simson would say DOH!
i forgot that yes the shrader will have to be depressed, so i will need that valve core tool and remove the shraders.
And yes i see your point about connecting 1/4 copper to the vg64. Im not sure if i can get a wrench on the vg64 to tighten copper to it. Il have a look. Many thanks for your help.
Ok so if i get a vacuum core tool AND one of these http://www.gascoireland.com/products/2006I06.pdf
Shut off ball valves
to connect to the vg64 and 2 1/4 inch flare nuts to connect copper to the ball valve and then the ball valve attaches to the vacuum core tool. This could work yes?
What hoses are people in the UK using for vacuum?
And if so any links?
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24-04-2010, 03:04 PM #15
Re: Micron gauge and vac loss
Lomb
I use a CPS gauge from RDL, if on a small split attach directly to manifold, as nike says achieve vacuum level and hold for as long as practical, i normally pressure test to 40B first for leakage.
alec
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24-04-2010, 03:04 PM #16
Re: Micron gauge and vac loss
Nike
Any prices on the appion manifold, looks very useful.
alec
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24-04-2010, 07:56 PM #17
Re: Micron gauge and vac loss
Hiya Alec
, well if my bench test experiment is anything to go by waiting for the vacuum to hold is possibly a mistake. If most hoses leak then air is reentering yes? This may not manifest when connected to an evacuated split as quickly as there is a far larger area of evacuated copper which would delay the microns creeping up as quickly. It is possible that as the hoses are new they are more permeable. Il investigate furthur on Monday and pick up some bits and report back.
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24-04-2010, 10:14 PM #18
Re: Micron gauge and vac loss
yeah, by there very nature flexible hoses will allow air ingress, the copper lines are great for larger systems, really speeds it up.
alec
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24-04-2010, 10:17 PM #19
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Re: Micron gauge and vac loss
Nope, check here.
http://www.appioninc.com/distributors/locations-uk.htm
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24-04-2010, 10:26 PM #20
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25-04-2010, 12:55 AM #21
Re: Micron gauge and vac loss
Nike
thought you had one, hence the price question, thanks anyway
alec
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26-04-2010, 12:57 PM #22
Re: Micron gauge and vac loss
I have ordered a cd3930
http://www.cdvalve.com/index.php?pag...mart&Itemid=60
And after opening the VG64 i can access the brass fitting safely to apply countertorque while attaching some flared 1/4 inch copper.
Will the core removal tool read vacuum with the ball valve closed and the manifolds isolated?
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04-05-2010, 10:37 PM #23
Re: Micron gauge and vac loss
I set it up today on the bench with a length of copper and a couple of flair nuts and this set up seems to be vacuum tight.