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M4X1MU5
19-02-2008, 08:31 PM
Hello my first post

Anyone have any advice on detecting a leak on 3 pipe VRV sytem over 3 floors high with approx. 20 cassette units attached to it.

Tried UV dye and the usual soap solution
going out of my head trying to locate this leak
my next step is to split the piping into three parts. Seal the ends and pressure test each on seperately hoping to find it.
Anyone got any advice :confused::confused::confused::confused::confused:

jacob odeyemi
19-02-2008, 08:51 PM
have you tried any of the leak detectors around? either electronic or ultrasound i think they are handy enough and will save you a lot of time and stress from jacob

Brian_UK
19-02-2008, 08:56 PM
Are you leak checking with the refrigerant present or are you using high pressure OFN ?

andy c
20-02-2008, 08:18 PM
If you know there is a leak somewhere on the system, then you will need to recover and weigh all the refrigerant. The chances are the system will be short of its correct charge anyway, so by recovering the refrigerant you will be able to calculate how much you need to put back in. Whilst the refrigerant is out of the system, you will be able to carry out a high pressure leak test which will find your leak(s). Once you've repaired the leak(s), you can carry out another pressure test (and strength test) to be sure you've no more, before evacuating and re-charging. Trust me- it'll save you time in the long term. Andy C.

Gwyn
20-02-2008, 11:17 PM
d-tek IR leak tester. Damn Grill thing, well recommended, already paid for its self. Only had it short while!

chris96
21-02-2008, 12:04 AM
just curious,

When you guys leak test with OFN how much "trace" refrigerant do you leave in the system to use your electronic leak detector, i was always told and therefore left 10 psi in.

By rights all should be removed i know but near every engineer i know does this - even the best.

(talking large systems really)

Chris

Brian_UK
21-02-2008, 12:51 AM
Gives you a lot of contaminated OFN to deal with at the end though doesn't it ?

Brian_UK
21-02-2008, 12:53 AM
Hey M4X1MU5

are you still out there ?

Tesla
21-02-2008, 08:30 AM
Hi Chris
I read in a book that the ASHRAE guide lines say 15 psi r22 is acceptable for trace then topped up with dry nitro

chris96
21-02-2008, 10:04 AM
Is that only for R22 then, what about 407c, thought it was ozone friendly compared to R22?

Chris.

M4X1MU5
21-02-2008, 09:04 PM
Yeah Guys Thanks A Whole Heap
I ended Up Spliting The Runs And Pressure Testing With OFN Found The Leak
The Previous Contractors Had Condemned A BS Box And Didn't Seal THe Piping Propely and Had A Hairline Crack.
THe Situation was not helped by the entire cieling being in plaster board. Ended up having the entire ceiling being cut open everywhere.

Again thnx guys

Brian_UK
21-02-2008, 09:13 PM
Glad to hear that you have found your problem and thanks for the update.

Did you get them to build in a proper access panel for future use?

nike123
21-02-2008, 10:55 PM
Did you get them to build in a proper access panel for future use?

That is what aggravates me most with interior architects. Their lack of cooperation on placing acess panels is more and more frustrating.
Again, I still exult when I need to open plasterboard to reach some component of system. :D:D