Hi all.

For the past 2 months i have been losing a 50 kg cylinder of r404a in one of my supermarket stores on average every 4 days from a h/t pack with 28 cases and 6 coldstore blowers.

As usual the first thing to do is give the whole system a leak test with my electronic leak detector and surprise,surprise could`nt pick up anything.
Now not being one to whack a load more gas in and hope for the best,and by going by the gas leaks i`ve had in this store since it opened 7 years ago,i arranged to have all cases emptied so i could access valves and coils.
NOTHING not a whiff.All pipework is accessible,leak tested everywhere and got nothing.

So i arranged for a pressure test,which i did over 2 weekends and having not lost pressure on any pipework i decided to pressure the cases even though i was told not bother as i had not picked up a leak with my detector.
4 lads spent all night cutting all evap coils out of cases and pressured each one with 200psi of ofn only to find not one dropped any pressure.

By now i`m getting a bit puzzled as to where this gas is going,even the gas detection system was clear.

So long story short i have spent all friday night and all saturday night cutting the coils out again,but this time i added some refigerant to the ofn and repressured,this time we found 3 coils p**sing out.
So to prove a point we just pressured back with ofn and it didnt leak.

My point is with these f-gas regulations are we not allowed to pressure test like this(gas/ofn mix)as the only way to empty the coil is to blow it off.

And be carefull when leak testing with d-teks and tec-mates detectors as it seems they can only pick up anything that isnt r404a.