I just had that guy from Vac-Tuator e-mail w/ the info. Sounds good anybody used this thing? Sounds like an info-mercial.
used it for 18 yrs. many big wrenches here use it or are familiar with. it' s a hermetic wet bulb t-meter, using carbinol (a type of alcohol). using a small amount, and care not to boil it off too quikly, the resulting temp. will correspond to your level of deep suk(tion). -12 on vacuator = 35 for aqua,5.2mm, 5200 mics. a little more sensitive to vac level rise, no merc to spill, no batterys, no calibration.
OK, The reality of it is that the Vac-u-Ator is the only frickin non-electronic vacuum testing instrument out there today. With the acceptable evacuation tolerances being a little loose(in my opinion), we just have to trust the instrument of our choice. Pull a large volume Centrifugal down to 1000 microns and let it stand for 12 hours. It is acceptable to have a 25oo micron rise... That is where I start questioning myself. But it is what it is. I would trust that anyone that has done 10-20 teardowns has had issues with a leaker. They're not fun. You finish a little ahead of time and wham your chasing a GD ghost. I did get the literature from Vac-U-Ator and after reading it makes me want to trust it a little more. Anyway, Thanks for all of your input, it really is a personal choice.
It just pisses me off that I can get a 400 ton 134a screw system down to 300 microns and get it to hold. But most times these low pressure machines are harder to pull down. It must have something to do with the large volume in the machine itself???
OK here goes!
I dont use my manometer anymore!
I dont use a vacume guage!
I can see it now your fingers burning to type
I use the discharge off of my vacume pump and have for about 15 years now. I can walk in room the morning after putting the machine together and tell you if there is a leak in 30 seconds without any doubt, no standing vac test no waiting till the next day to start the machine.
One Disclaimer: Im talking low pressure machines!
I will do the same on high pressure but I will also use manometer.
Here is another one, I use a small 10 CFM pump instaed of the big welch pumps Unless I am in a hurry or have a wet machine!
I reduce the discharge of the pump down to 1/4 in and run a hose into a cup of oil and let set for a few minutes. I have "with experience" developed an eye for what is or is not a leak buy the amount of bubbles being exhasted. If there is nothing coming out of the pump there in nothing going into the pump and there are no leaks period! This has been a great way for me to elimanate doubt about whether my manometer has a bubble in it, or is the pump overcoming the leak ,or is that a mil or 1/2 a mil rise. You do have to check your pump and know it will pull down flat. You also have to close the service valve on the chiller before evacuating and check that there are no bubbles indicating a leaking hose or pump. This is not a good practice if the machine is wet were the water can freeze. In that case you still need to do the standing test. This has worked better than anything I have tried and I heard that some of the absorber techs did something like this. If you dont like it because I'm not doing it the "right way" you can keep doing it the "right way" but I callange you to try something new you might just like it!
"Dying aint much, its living thats hard." (Josey Whales)