[AT] Air conditioning problems In my parts getter...

[Steve W.]

Brad Loomis wrote:
> In the trade one always uses nitrogen. Co2 has moisture, bad in sealed 
> systems. Of course you're supposed to evacuate to <500 microns but...
> I once had a13oz. R-12 system that I never found the leak. From 150psi 
> nitrogen to my brand new, then, Inficon leak detector. 
> Check your Schraders after you put the caps back on. You may be surprised. 
> Why I preferred leak finding after I moved to NH3. Easy, save for having 
> to cut the skin off a double stainless jacketed 155,000 gallon tank. But 
> the leaks were always in the same areas. 
> Brad
> 

Depends on the shop, I know of some that use shop air! I've had a few 
leaks that didn't show up under system pressures in operation, but once 
equalized from setting overnight you would find a bad seal or O-ring 
that wasn't seated quite right. Had one that would leak under pressure 
but would hold a vacuum forever, that was a piece of rust that acted 
like a check valve!

-- 
Steve W.