Strange Leak

[ndavis2]

Heres the problem:

I have a dual regulator, put 30 psi to seal the corny and check for leaks with star san, none. The high pressure dial reads 500 psi and the regulator dial 30 psi, fine. If I turn off the cylinder main valve, after about 2 sec the high pressure drops to 0 psi and I hear a hiss during it. The corny is down to 0 psi next day. A lot of traffic talks about the cylinder valve being "back seated" and the valve always has to be open, but this bleedback doesnt always happen. Is there any kind of pressure relief valve in the regulator that explains this or is it indeed the cylinder valve seat? It seem to be kinda delayed, as if purposeful? Happen to anyone else?

Thx Harris

 

[Bowtiebrewery]

is this a single output regulator? If so i can see how the regulator may only maintain an equilibrium and when one side of the reg is off (the input side) and the output has a 30psi load on it... it will drain it out... Sounds like there is no check valve on your regulator... see if you can get one of these to remedy the sitiuation

http://morebeer.com/view_product/16208//Shut_Off_Check_Ball_Valve

 

[shortyjacobs]

It is, indeed, back seated. Here's a picture:

Also, even if you have a check valve between keg and reg, gas will still leak back past it and keg pressure will drop to zero. The check valve just stops fast leaks, but doesn't seal positively enough to stop slow leaks.

 

[mattd2]

Shorty: MS Paint FTW?
Nice explaination by the way.

 

[shortyjacobs]

Shorty: MS Paint FTW?
Nice explaination by the way.

haha, OpenOffice.org "Presentation", actually....I drew it months ago and just keep copy-pasting it when I see these threads....I drew it at 3 AM, so don't judge!

 

[ndavis2]

Thx Shorty

Guess I just got paranoid, because my first CO2 tank only lasted 4 kegs (10#). Have you actually experienced a backpressure loss like this? The strange thing is how when you turn off the main tank valve the high pressure gauge takes 2-3 seconds and then you hear the hissing and drops to zero. Anyway, guess I'll man up and just leave it on all time again and see what happens, no leaks I can find.

H

 

[shortyjacobs]

Sounds like you have some reason to be paranoid...4 kegs for 10# is about half of what I would expect, even on the low end. I suppose you could have spent a lot of gas purging kegs or whatnot, but still that seems low.

I have found that if I shut off my tank connection, but leave all other valves open, my high pressure side will first drop, (takes a while for me, but each tank valve will be slightly different), and then over the course of a few days my keg pressure will drop as the gas bleeds past the check valves.

My only advice is to spray everything with starsan and watch for bubbles...listen carefully for hisses.....I'm not saying you don't have a leak, I'm just saying that the "shut off the tank and wait" test is useless, as it will always give a positive result, whether you really have a leak or not.