You don't need a "charge" to check for leaks. It just takes a very small amount in order to pressurize the system enough to get it to 40-60- psi. A few ounces. Pick up a can of the 134 at the auto parts store and just use a partial can to pressurize it then check for the leak. Feel free to call me if you would like. And yes, I am 30 miles east of the "Burgh". 724-694-2711

 

Actually, what garages do is not pressurize the system, but evacuate it. There are small vacuum pumps that can do this job. You pull a certain level of vacuum and then you stop the pump (it needs a one-way valve to not leak out) and you should be able to maintain that amount of vacuum for a good half hour or more. It is best to have gauges to see real numbers at the beginning and as you progress. Hope you make some real progress on this!

 

Thanks but you didn't quite catch the whole conversation. A vacuum will show that it is leaking but good luck trying to find the leak in a vacuum! You have to pressurize the system to actually find where it's leaking then use the most primitive form of leak detection on the planet. They call it "soapy water"!

 

^^^100% correct! Knowing you have a leak is one thing, knowing WHERE the leak is requires pressurized media that can be sensed with leak detection devices or materials is how leaks are found and repaired.

On side note about leak detection and prevention: When I was working at Liebert Corp we'd electronically test for leaks as our units were installed inside computer rooms of the 70's and beyond. Our equipment would test down to a leak rate of 2/10 of an ounce per year. Putting that into perspective if a pressurized vessel with that leak rate were submerged in a water bath it would take eight hours for a bubble to develop.

We built good stuff, had near-laboratory test gear to assure it was top quality.

Good times!

 

JWA,
Lieberts never leaked! There bullet proof! I loved working on those units. Serious engineering just like Mercedes..... My cheap $1000.00 sniffer is only good for a 1/2 ounce/year leak. It has a UV light incorporated in it too which comes in handy when you add the dye to the system.

 

I like the idea of UV dye as a big picture leak detector, something that lets you know there IS a leak and it's helpful localizing it whether in a made fitting or like in my case a huge gaping hole caused by a missing wrench.

At Liebert our Inficon detectors were costly and very sensitive but for the time they were easily used even in the CFC environment we had at the leak testing station. We'd charge the made system with a mix of R-12, R-12 or R-500 and nitrogen, look for leaks and repair accordingly. If repairs were required we simply vented the refrigerant/nitrogen mix into the shop air and thought nothing of it. Talk about a waste and as it turns out a growing environmental problem. I recall my QC department manager doing all the preliminary work to spec out a recovery unit, how we'd recoup its cost inside the first year, about $50K which was a lot of money back in the 70's. That idea was immediately shot down by the owner's son-in-law (aka "vice president of manufacturing") as a frivolous expense, refrigerant was so cheap.

The VP decided instead to completely revamp our production floor which was about 50K ft/sq in order to make things LOOK "better" to his eye. Mind you this guy was a licensed pipe fitter who was instrumental in developing the first Liebert units we tried selling to IBM, that would have been in the middle 60's.

We made great stuff but cold and did waste money like we were grossing over $260 million annually in 1975---which we were.

 

Well Inficon must have been in the game for a long time because that's the brand of my leak detector. I've had their brand for years but when they started coming out with the refrigerant "blends", their detectors where very unreliable. I'd pressurize the system with R-22 (and yes, it was very cheap back then) then grab the halide torch! The good ole days!