[pony]

i pressure test a old case coil from customer i replace,when apply first 150 lbs pressure use soap and it show samll leak,and i hook up pressure gauge to it just see how accurate my pressure gauge is ,but it start increase pressure while coil is leaking???i was thinking maybe need to blow the inside coil out with nitro which i did and repressure coil to 200 lbs,and the pressure gauge start show micron leak,but when i put the soap on the leak spot it stop leaking?just puzzle me why?and i try few more time on same spot it wont bubble up at all???no wonder some post here said cant find the leak,is there any solid good method to find the leak?

 

[glennac]

When all else fails use dye. Thank you very much.

 

[garyed]

When it comes to finding the area where the is a leak there is nothing better than a good electronic leak detector. It can pick up in places where bubbles won't show or dye can't be seen when its underneath & out of sight. To really pinpoint the leak then it takes dye or bubbles but some leaks can be pretty tricky about showing up & be pretty frustrating. There is no fool proof method of finding leaks so its more a matter of what works best for you.

 

[walterc]

I agree with garyed.
If soap doesn't show a leak you suspect it to be at (Due to oil or corrosion) I use the H10 to see if the leak is in that area, then try and pinpoint it with soap.
My H10 does read 410 but not near as well as r22, so if I can or I really need to, I'll pump the system down (Looking for inside leak) and add a little r22 and nitro to find the leak quickly.

Perhaps nitro has bigger molecules than refrigerant? :grin2:
Never gave that much thought, but something to find out.

 

[Northfloridatech]

Infrared leak detector by fieldpiece.:grin2:

 

[lytning]

Wonder how that would work with propane.

Infrared leak detector by fieldpiece.:grin2:

 

[mason]

Remember, the higher the pressure the more likely it will blow out solution and not show any bubbles, try a lower pressure with a really good solution like "Big Blue" or nu Calgon blue.

Pretty much I've found 200+ doesn't show bubbles on larger leaks but it does make it easier to hear : ).

If you have air in the container it will be effected by temp change more than straight nitro. Even with straight nitro if you pressurize just an evap coil and say the sun comes out and starts heating it up in the yard you will see an increase in pressure with digital gauges.

 

[RACMT]

There is no one best method to finding a leak but applying the right method to the type of system or refrigerant is key. So if you have a case coil (meaning a small residential manufactured encased coil that has been takin out of service?) and you are curious to the location of the leak for personal satisfaction but having no future plans for re-service then the best way to find a leak on this type of coil is to flair or braze closed the liquid line and put a port on the suction, pressurize with nitrogen to 50-100 psig and put it in water and the bubbles will be evident.

 

[Texanna Slim]

Inficon Techmate on sale at Johnstones. Best detector for the money IMHO.

 

[Gunslinger]

Inficon Techmate on sale at Johnstones. Best detector for the money IMHO.

Just make sure the sensor is in the blue package.

 

[bandity2k00]

i love using my h10 its a great leak test meter..if it dont work i use big blue..if that dont work i use dye..