Weird gas leak - but where from?

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cat007

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Hi all,

I have a gas leak that I thought was either a bag keg lid seal, bad hose clips, bad distribution tap or something else - turns out, it's something else.
If I turn the reg down all the way, so much so that the knob is totally loose, and turn the gas bottle on, the high pressure gauge reads around 800psi. Then I turn the bottle off and slowly the high pressure gauge will drop. Not really fast enough to see - but after 5 minutes it's down to 500psi and eventually (by the time I'm writing this) it will go to 0psi.
I've tried the soapy water trick, but I can't see any bubbles coming from anywhere.
It's doing my head in!

Is it possible the gauge is faulty? The reg is pretty new, only about 5 months old. It is the kegland MKIII reg.

Any ideas on what I could or should be looking for?

Thanks in advance

Hunt
 
Submerge everything you can in a bucket of water, and look for bubbles forming in there.
 
I use starsan out of my spray bottle to find leaks. If you cant find it easily, isolate all the parts of your gas system...

- Disconnect all kegs from the CO2 disconnects, apply normal pressure from regulator and wait and see if it drops, if it does, its something leaking on the regulator, disconnects or tubing/joins/manifold etc.. In which case, dunk everything (minus the reg) in a bucket of water for 10 mins, that will show up event the smallest amount of leaking co2. I recently had a tiny leak in my co2 manifold which i could only see when submerged in water and the leak built up enough to show a big bubble.

- If the above shows no leak, connect up to one keg at a time until you hit the leaking one (may be more than one though). If it drops on a keg, check the lid seal and post seals etc..
 
A couple of places i have had leaks over the years for reference:

- Around keg lid seal, the metal was a bit bent out of shape - Still happens to this day, just need to move the lid side to side sometimes.
- Around manifold tap, just needed some thread tape.
- CO2 Line was cracked at the end of the barb on the regulator.. probably from too much movement (was also my portable picnic reg). Replaced the line.
- CO2 disconnect, leaking around poppet pin. Didn't do anything, just repositioned poppet pin.
- Push fitting.. had some of those terrible old KK push fit fittings. They leak at the slightest movement. Threw them out and moved to John Guest.
 
Probably a self relieving regulator, its a safety feature on some regs, designed to let all the high pressure out from under the diaphragm.
If you look around the top of the reg housing (the part the screw adjustable pressure control knob goes through) you will probably find a hole drilled through the housing, to let the gas out.
Common enough and only happens when you unwind the knob all the way.
If you want to know for-sure take the housing off, have a look at the diaphragm if there is a hole all the way through the centre, its self relieving, if not you will need to look elsewhere for your leak.
Best way to find leaks is with Snoop leak finder, or make some of your own: -
About 100mL of dishwashing detergent, 100mL of Glycerine in a 500mL spray bottle, top up to about 400mL with water.
You can get away with 50/50 Detergent/Water but adding the Glycerine makes for much bigger tougher bubbles that are much easier to spot (kids love it to).
Mark
 
I could hear the leak coming from the high pressure gauge so I took the rubber cover off the high pressure gauge, and the backing plate so I could see the insides.
Low and behold there is a leak where the copper tube in the gauge is solder to the bronze block.
I have called the supplier and will go from there. Annoying as I have been chasing this leak for a couple of months and 2 bottles of C02 later.
 

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I could hear the leak coming from the high pressure gauge so I took the rubber cover off the high pressure gauge, and the backing plate so I could see the insides.
Low and behold there is a leak where the copper tube in the gauge is solder to the bronze block.
I have called the supplier and will go from there. Annoying as I have been chasing this leak for a couple of months and 2 bottles of C02 later.
That's what spoly ended up doing, seems the quality control is no existent.
 
That's what spoly ended up doing, seems the quality control is no existent.

Yeah - which is annoying as it's cost me 2 bottles while I try and track the fault down. Also it didn't do it all the time - which was awful to troubleshoot!
 

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