Author Topic: PRESSURE GAUGE USE  (Read 4482 times)

Offline diyguy

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PRESSURE GAUGE USE
« on: October 16, 2008, 05:41:45 PM »
After disconnecting my gauges from my mothers outside unit, (my practice unit) there was still pressure in the hoses,is it illegal to purge the hoses(gauge) afterward, and would it have made a difference if I would have turned the unit off before disconnecting the manifold gauge?

Offline JWWebster

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Re: PRESSURE GAUGE USE
« Reply #1 on: October 16, 2008, 09:57:49 PM »
Why purge the hoses right then? You never want any air in there which could cause ice inside the sealed system. If the freon stays in the hoses while they are not in use it is a good thing. There is a quick connect adapter you can put on standard hose that holds in the freon. I cannot remember what it is called but I have em on my hoses.Stops the dang hissing and finger freezing. and is big enough to quickly remove the hoses without getting frost bite. Dang it I can't recall the name of it.
« Last Edit: October 16, 2008, 10:37:36 PM by JWWebster »
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Offline RegUS_PatOff

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Re: PRESSURE GAUGE USE
« Reply #2 on: October 16, 2008, 10:16:50 PM »
http://www.epatest.com/608/manual/manual.jsp

about halfway down the page ...


"Prohibition on Venting
 ...- Small releases of refrigerant that results from purging hoses or from connecting or disconnecting hoses to charge or service appliances will not be considered violations of the prohibition on venting. However, recovery and recycling equipment manufactured after November 15, 1993, must be equipped with low-loss fittings."
« Last Edit: October 16, 2008, 10:53:29 PM by RegUS_PatOff »
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Offline JWWebster

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Re: PRESSURE GAUGE USE
« Reply #3 on: October 16, 2008, 10:22:56 PM »
When you go to hook up the hoses to the next unit you need to check, you THEN purge them hoses. Making sure no air has gotten into them before charging another unit.
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Offline RegUS_PatOff

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Re: PRESSURE GAUGE USE
« Reply #4 on: October 16, 2008, 10:54:23 PM »
When you go to hook up the hoses to the next unit you need to check, you THEN purge them hoses...

unless it's a different Refrigerant ...
« Last Edit: October 17, 2008, 04:11:17 PM by RegUS_PatOff »
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Offline JWWebster

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Re: PRESSURE GAUGE USE
« Reply #5 on: October 17, 2008, 08:33:14 AM »
Low loss fittings is what I was talking about.
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Offline diyguy

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Re: PRESSURE GAUGE USE
« Reply #6 on: October 17, 2008, 03:17:32 PM »
Well here's the thing, I did purge them when I first hooked them up(which are low loss fittings by the way) so as to not get any air in the system, and when I disconnected them ;there was still some refigerant in the hoses so when I opened the fitting on the liquid line hose (after being disconnected) liquid started to come out, but by opening the valve on the high side of the gauges and then opening the compound side hose fitting a quick vapor released. Once again I'll ask though; does it make a difference if the unit is shut off before disconnecting?

Offline Repair-man

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Re: PRESSURE GAUGE USE
« Reply #7 on: October 17, 2008, 03:28:34 PM »
On a condenser unit, you will lose a lot less Freon if the unit is shut off. When running, the head pressure is over 200 PSI, when idle, only about 100 or so. You lose a lot of liquid in a short time if it is running when you  disconnect. With the special hoses they mentioned, you can disconnect running or not...there's basically no loss at the unit. Leave whatever is captured in the hose for the next  unit or recover it.
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Offline diyguy

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Re: PRESSURE GAUGE USE
« Reply #8 on: October 17, 2008, 03:35:10 PM »
I'll do that and thanks to everyone for all the help  O0

Offline Icehouse

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Re: PRESSURE GAUGE USE
« Reply #9 on: October 23, 2008, 09:16:20 PM »
 :) When finished with any system, remove gauges as follows.
1. With unit running, close (back-seat) the "high-side" service valve if so equipped.
2. Remove "high-side" hose, and connect to holder.
3. Charging or center hose connected to holder
4. Open "high-side" hand wheel on gauge manifold
5. Open "low-side" hand wheel on gauge manifold allowing the  refrigerant to be pulled into the "low-side" or suction side of compressor.
6. Close both hand wheels on gauge manifold.
7. "Back-Seat" suction service valve if so equipped
8. Remove "low-side" hose.
9. Replace all caps'
By using this method you leave the refrigerant in the unit. This is espceilly important with "critical-charged" units.
NATE, NCCER, PHCC,HVAC Certified Instructor
Member RSES, US Army Refrigeration Specialist(Retired), Former Refrigeration Teacher NYC Board of Ed.
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