Leak rate

[amazing azza]

Hi friends,

I've been spending time searching for leaks in my refrigerant lines. I am having a hard time finding some of them. I know there is a leak from nitrogen pressure testing, but I am failing to find it. Is there an acceptable threshold for leakage? If so, what is it?

For example, I have one leak that I measure to be 0.0031 mbar/s. If my system is between 10-100L (don't know exact volume) that would make a leak rate of 0.031..0.31 mbarL/s.

PS. My measurement procedure. Fill to 150 psi, take readings over several days. Plot pressure vs time, slope is the leak rate.

 

[itsmoked]

Absolutely NO leak should be present. When done with the installation you put something like 30psi of refrigerant in to the system then use a leak checker. The leak checkers are insanely sensitive and will guide you quickly to each and every leak - something impossible with N₂.

This one is generally considered around here to be the gold standard of leak checkers. It found all my problem leaks. It's both audible and visual at the probe tip. Notice the calibrator in the bottom left corner. You get it clicking (detecting) on the range you're interested in on the calibration point then attack your piping.

[URL unfurl="true"]https://www.mybacharach.com/product-view/h-10-pro/[/url]

Once all leaks are repaired you put your system under a vacuum pump for 24hrs. Then charge the system. Don't forget oil if it's called for.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[amazing azza]

itsmoked, ah, I see.. Will try again with a halogen leak detector. Have been using ultrasonic, but it's just not picking it up.

 

[itsmoked]

LOL I cross updated my post.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[amazing azza]

wow, now that, is nice!

 

[Strong]

Ultrasonic leak detection sensitivity can be enhanced by spraying water or a light oil (WD40) on surface. The popping bubbles can produce more sound than a very small leak, plus is easier to find location. I have also used a focusing sensor (microphone) that increases sound level and location detection. Make the best use of the tools you have!

Walt