moisture, or just impatient?

[Thorazine]

Does your vacuum pump have a gas ballast port? This is from Yellow Jacket U If you suspect an open or wet system, be sure to use the gas ballast feature on your vacuum pump. The gas ballast prevents water vapor from condensing in the vacuum pump oil by introducing a small amount of fresh air into the pumping chamber. Open the gas ballast just slightly and then begin to watch your electronic vacuum gauge. If the vacuum stays at a consistently high level of microns or doesn’t pull down below 5,000 microns, your system still contains contamination or has a leak. Repair the leak before proceeding.

[Tommy knocker]

If your hitting 500 micron and can hold it , or at least under 700 for 1/2 hr I'd say you have clean tight system. Doesn't matter how long it takes to get there as long as it gets there. As previously stated your 410A systems will take longer, much longer in some cases, then the R22 systems with MO. POE likes liquid be it refrigerant or water. Once it gets ahold of some it will not let it go without a long hard fight. Your procedures sound good and proper so relax and be patient. On a side note I like to use brute manifold set with 3/8 hose. Get a vac pump with a 3/8 connection and pull through it. Will make a big difference in pull down time.

[chill4good]

Does your vacuum pump have a gas ballast port? This is from Yellow Jacket U If you suspect an open or wet system, be sure to use the gas ballast feature on your vacuum pump. The gas ballast prevents water vapor from condensing in the vacuum pump oil by introducing a small amount of fresh air into the pumping chamber. Open the gas ballast just slightly and then begin to watch your electronic vacuum gauge. If the vacuum stays at a consistently high level of microns or doesn’t pull down below 5,000 microns, your system still contains contamination or has a leak. Repair the leak before proceeding.

I've always achieved 300-500. I don't think I have any leaks.

If your hitting 500 micron and can hold it , or at least under 700 for 1/2 hr I'd say you have clean tight system. Doesn't matter how long it takes to get there as long as it gets there. As previously stated your 410A systems will take longer, much longer in some cases, then the R22 systems with MO. POE likes liquid be it refrigerant or water. Once it gets ahold of some it will not let it go without a long hard fight. Your procedures sound good and proper so relax and be patient. On a side note I like to use brute manifold set with 3/8 hose. Get a vac pump with a 3/8 connection and pull through it. Will make a big difference in pull down time.

I was concerned of my method to keep vacuum sterile. I guess without oversized hose, it'll be turtle slow. Company wont budge on equipment. I had to fight to get a new pump, because a coworker dumped 10w-40 in it....

Yeah.....




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[syndicated]

Why not buy your own tools, that way you can take them with you and no one else can mess with them?

[chill4good]

Why not buy your own tools, that way you can take them with you and no one else can mess with them?

I was hired to replace sinks and buff drywall repairs. Handbook said basic tools required. They want hvac fixed, they can fork out some hardware my opinion anyways.
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[R123]

Your methods look good but I would blow out all of the nitrogen before you hook up the vacuum pump. Your not going to get any moisture going into your system through your 2 hoses and manifold by letting all the nitrogen out.

[valdelocc]

I use to have a Robinair 6 CFM. I hated the thing. I suggest you buy a more reliable vacuum pump. It is expensive but you will get your moneys worth. Buy the Appion TEZ8 and the MegaFlow Speed kit.

how about running a piece of tubing all the way to the stratosphere? the best vacuum pumps are free and highly reliable.

[Chuck]

how about running a piece of tubing all the way to the stratosphere? the best vacuum pumps are free and highly reliable.

Wouldn't work.

You would have no suction at all on the bottom of that tube.

[XcelTech]

I find that free is a German word for doesn't work and will make your day a living hell.

[ndk1911]

Vac pump oil breaks down because of contaminants, heat, etc.. You're not helping your pump by using it to pull nitrogen out.. Also, the rotary vanes aren't supposed to be exposed to positive pressure.. Let your nitrogen blow before starting pump, you wont be introducing contaminants.. I used to abuse my pumps and learned that if you show it some love it'll return the favor , in the form of making a job much less stressful..

[valdelocc]

Wouldn't work.

You would have no suction at all on the bottom of that tube.

I tried once and got down to 500 microns in 2 minutes and 55 seconds, dont need no super duper mighty vacuum thingy.

[chill4good]

Vac pump oil breaks down because of contaminants, heat, etc.. You're not helping your pump by using it to pull nitrogen out.. Also, the rotary vanes aren't supposed to be exposed to positive pressure.. Let your nitrogen blow before starting pump, you wont be introducing contaminants.. I used to abuse my pumps and learned that if you show it some love it'll return the favor , in the form of making a job much less stressful..

15-20# tops.,and I tease the valves at first, I don't whip them wide open from the get go.

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[carmon]

steal there tools .....lol

[Six]

Actually there are a few devices you can attach to your vacuum pump that will actually allow your pump to " give you love ".

You just won't find them at johnson supply.

[ICanHas]

how about running a piece of tubing all the way to the stratosphere? the best vacuum pumps are free and highly reliable.

It would work as well as sticking a 1000' pipe into the ocean and expecting water to come gushing out at the top. After all, the pressure gets higher at depth right? It works the same way with air. It just takes more distance to develop the same pressure gradient since air weighs nowhere near as much as water.