Help troubleshooting kegerator leak

Hi all-

I recently built a kegerator out of a chest freezer. It uses a secondary bank of 4 regulators (of which I purchased from American Science and Surplus - great deal!), and I'm trying to track down a leak somewhere in my system. So far, I've killed about 3-5lb CO2 tanks trying to diagnose this.

I currently have three kegs connected to the secondary and I've checked all hose connections in my kegerator using soapy water in a spray bottle. I checked all the fittings within my secondary bank as well (psi gauges, nipples, etc), and even ensured that the new C02 tank and primary regulator aren't leaking either. So far, it all looks good.

I'm kind of stumped as to where my CO2 is going. So, in desperation I shut off the CO2 tank completely, and I noticed that eventually all 4 psi gauges on my secondary go down to 0 (they're all set at ~ 10psi). If I let the system site with the gas off for a couple hours and come back and turn it on, it sounds like the the system is filling back up with gas.

My question is, if I didn't have a leak, I should be able to shut the gas off, come back in a couple hours, turn it back on, and nothing should happen right? At the very least I shouldn't hear gas rushing through my system should I?

I'm kind of stumped as to where this leak is, and I'm starting to focus more on the secondary bank because of this.

Does anyone have other thoughts or suggestions on what to focus on? I just need some more ideas!

Yes you should be able to shut the gas off and have the system hold pressure assuming there are no kegs hooked up and conditioning. If there are then the leak could be in parts of the kegs. Also the the tank valve must be to the complete and seated open position or a leak can occur there.

Well, just back up for a second. Are you positive that all the beer in the kegs in question are fully carbonated already? If not, gas is going to continue being absorbed from the headspace and into the beer causing a drop in pressure.

Here's how you test the gas system by itself. Disconnect the hoses from all the kegs, set your regulators for say 15 psi. Turn the tank valve off. Come back in an hour and see if you still have 15 psi. If you do, your plumbing is sound.

You can test your keg integrity by hitting it with 20psi, disconnecting, then turning it upsidedown on a paper towel. If you get dripping, you know it was leaking gas.

I have multiple secondaries (from AS&S) and have noticed that a leak anywhere in the system will result in all of the lines de-pressurizing. I suspect the secondaries will back-leak internally if the primary pressure drops, so figuring out where the problem is a pain. I went so far as putting isolation valves between the secondaries. So, I know which secondary is leaking. I think it is actually the gage & some day I'll replace it. For now, I use the isolation valves.

I've always though that check valves belonged at the gas in connection to the keg so that a leak in the system will not depressurize the other kegs. It would also prevent un-equal pressures from causing reverse flow into the gas lines.

I do have check valves on each regulator of the secondary. I was skeptical about one in particular so I shut the valve off, and my C02 was still drained. I then noticed the whole issue that I posted about above.

Bobby, that's a good idea. The beer that's in the kegs now should be fully conditioned. They've been connected for weeks (going on months). But I'm definitely going to disconnect all the kegs when I get home and make sure the regulators are set at 15. Then, I'll just let the system sit after turning off the gas. If it doesn't leak, I'm going to test the kegs themselves.

I already returned one keg that I thought was the cause of all this. But I suppose it could be more than one thing/area causing leaks.

I'll tell you, next time I build something like this I'll definitely test each component fully before installing everything.

Anyone out there thinking about building something like this, definitely test, test, test!

I also want to suggest that you use keg lube on all your O-rings. It's good stuff.

Are you sure the regulators you are using on your secondary are made for this application. I don't know what you bought, but some regulators bleed by design. I recall looking at American Science and Surplus before, and I thought their gear was kinda strange looking, with odd threads on the ports. I'd plug off all the ports on the regulators and start there pressure testing with soapy water, (or Snoop). Do you have the washer in place at your c02 tank connection as well?

mr x said:

Are you sure the regulators you are using on your secondary are made for this application. I don't know what you bought, but some regulators bleed by design. I recall looking at American Science and Surplus before, and I thought their gear was kinda strange looking, with odd threads on the ports. I'd plug off all the ports on the regulators and start there pressure testing with soapy water, (or Snoop). Do you have the washer in place at your c02 tank connection as well?

Click to expand...

I purchased the regulators based on a thread somewhere on HBT where others used them for exactly this (you can search for part number 36807P1 on sciplus.com - can't find link right now). The threads are standard 1/4" npt. They have three of them. One port I have a psi gauge on it, the other two ports are connected to other regulators to the left and right with the last regulator in the chain having a 1/4 plug in it.

And yeah, the washer in the C02 tank is there. I WISH it was that!

When I look at that item, it tells me one of the threads is 7/16"-18, which is really strange.

mr x said:

When I look at that item, it tells me one of the threads is 7/16"-18, which is really strange.

Click to expand...

I think this came up in that thread too. I believe that the site is incorrect because I'm using all 1/4" fittings and they fit perfectly.

Ok guys. I just want to start by saying thanks for the help! I figured out where my leak was.

I started by disconnecting the air lines from the kegs and turned the CO2 back on to re-pressurize the secondary regulators. Came back an hour later and sure enough they were all reading 0. So it obviously wasn't the kegs that were leaking.

I took the secondary off the wall of the kegerator and re-pressurized it. I then used more soapy water to wet ALL the fittings and sure enough I had two check valves that weren't sealed tight enough. I took them off, put new teflon tape on them and put them back and all is well. I've had pressure for the last two hours now!

Thanks again guys! Much appreciated.

Did you take your regulators to a hardware store or someone with a thread gauge?
I found this link that shows "standard not SAE" machine threads, like for coarse threaded nuts & bolts:
http://www.engineershandbook.com/Tables/tapdrill.htm

I found this thread for pipe threads, which are tapered:
http://www.engineeringtoolbox.com/npt-national-pipe-taper-threads-d_750.html

This link shows a variety of flared fittings:
http://www.kurthydraulics.com/threads.php

Do your fittings match the regulator threads? Did you use Teflon tape?
There is a variety of fittings & thread counts & pitches & diameters out there. Hope you get the leak fixed.
Never mind, I just saw that you got it fixed! I need to be more awake before I post this early!

I'm bumping this thread b/c I have the same regulator set up and I'm having leak problems, too. Wizard, are yours still holding pressure?

I submerged the whole thing up to the regulator threads in a tub of water and found that mine are leaking in about the same place - where my check valves screw into the regulator body.

I reapplied teflon tape and screwed them in as far and as tightly as I could, but the leak is still there. I'm thinking I might take apart the whole thing (while I'm at it and just to be safe) and reapply teflon tape, but also use some plumbers putty - maybe even some silicone caulk where the threads meet the regulator body.

Any thoughts, suggestions, ideas? Am I on the right track?

The pic below I stole from Wizard. It is almost exactly what I have, except I went with Northern Brewer #K043 0-30 PSI R.H.T gauges and 1/4" MFL check valves instead of the barbs. The gauge connections to the regulator bodies all seem okay.

How many wraps of Teflon tape are you using? I would suggest 5 wraps if you are having leak problems. If this doesn't solve it, then the leak is not through the threads.

Boerderij Kabouter said:

How many wraps of Teflon tape are you using? I would suggest 5 wraps if you are having leak problems. If this doesn't solve it, then the leak is not through the threads.

Click to expand...

Just one or two. I can see the bubbles coming out right where the valve goes into the regulator. I'll quadruple up on the tape and see if that does the trick!

It's hard to have too much teflon tape. I wrap mine till the threads are no longer V's, but look more like rounded bumps. Failing that, try a liquid thread sealer and/or look for a crack near/in the threads.

Check the threads on the female end. I busted a thread on one of my brass Y's doing some moving around last weekend. It was a very noticeable leak though.

Thanks for all the replies. I went 5-6 wraps of teflon tape and pipe dope, put it back together and let it sit overnight. Going to give it a test when I get home tonight. I'll post an update later...

Well, I'm at my wits end! I did everything suggested - multiple turns of teflon tape, pipe dope, retightened connections, checked for cracked threads - and there is still a leak somewhere. I can hear the tank out-gassing when open. When I turn it off at the regulator, it stops. I dunked everything up to the dial face in a tub f water and saw not a single bubble! I sprayed soapy water on all the connections from the tank to the manifold and still no bubbles.

Now I'm wondering if I have the regulators oriented correctly. I'm going to take some pics of everything and post them later, maybe under a different thread, in hopes somebody with these American Sci. & Surplus regs can respond and tell me I've made some bone-headed, obvious error that I'm just overlooking.

You may have to take apart the regulators from each other and check them one at a time.

Do you have the little washer in place at the CO2 tank connection?

If you can hear gas constantly moving, it's got to be easy to find.

Sorry Rhoobarb, I just saw that this thread was bumped....

I haven't been having any issues with my regulator setup. I know this because I can turn off the gas at the tank, and the 4 regs hold pressure overnight at what I have them set at.

BUT, I do have a leak somewhere from my secondary bank to the tank itself, possibly in my main regulator. I noticed that I didn't have teflon on the cylinder valve nut. I put teflon tape on and I'm curious to see if my tanks last a bit longer.

If I'm understanding you correctly, you're still suspicious of your secondary regulator bank? Do you have kegs connected? If so, the first thing I would do is disconnect them.

Then I would make sure your check valves are all SHUT and turn off your gas at the tank. If in a couple hours the gauges go back to zero, you know you have a leak somewhere from your secondary to your tank (primary regulator included).

Can you disconnect the secondary and put some type of check valve on the end of your primary regulator/air line? That way you can pressurize that primary line so your can read a psi on your primary gauge. Then, shut the gas off. You should still see a positive psi reading on the primary gauge.

Let that sit a couple hours. If you come back and it's down to zero, it's something in your primary up to/possible including that check valve you have at the end of your primary line.

Try putting some non-scented soap in a spray bottle. That helped me immensely to track down my leaks.

If you do have kegs connected, I would try shutting each line off at the check valve one by one while leaving the gas on for a couple hours between each test. That might help you narrow down a keg/airline leak.
Hope this helps...

mr x said:

You may have to take apart the regulators from each other and check them one at a time.

Do you have the little washer in place at the CO2 tank connection?...

Click to expand...

Yep; have that.

Thanks again, everyone. I'm now at the point where I am going to completely disassemble eveything, re-tape or maybe even use blue Loctite instead of teflon tape after reading a post on another thread opting for that as a better solution. I'll post some pics and keep you updated on what I find. Maybe what I find in my system will help someone else down the road with theirs.

Well, I feel like a bonehead and am a bit embarrassed to admit to what seems to be a stupid mistake on my part. But I'm going to post it anyway, just in case someone else out there is a dumb as I am about how to put together a bank of secondary regulators. Here was my mistake:

Apparently the "gas in" flows one way through these regulators! I had all my regulators lined up and everything oriented correctly, except I had the "gas in" entering from the left and my plug on the right! After much dismantling and retaping, I finally noticed that everyone had their "gas in" entering the regulator body from the right side! So, I hit my head in an "I coulda had a V-8" fashion and reversed the plug and "gas in". Now that everything is going from right-to-left instead of left-to-right, everything works great!

I think the only problem I may have now is one (out of the four I have) faulty gas line/disconnect going from the regulator to one of the kegs. But that's an easy fix.

Thanks to all who offered advice. It's great to finally have perfectly carbed beer and not have to turn valves on and off to save CO2. SWMBO & I sat up until 11:00pm last night watching the NCAA basketball tourneys and enjoying homebrew!

Rhoobarb said:

Apparently the "gas in" flows one way through these regulators! I had all my regulators lined up and everything oriented correctly, except I had the "gas in" entering from the left and my plug on the right! After much dismantling and retaping, I finally noticed that everyone had their "gas in" entering the regulator body from the right side!

Click to expand...

Wait. It matters which side is In? ****.

I JUST finished 3 hours of (very, very painful) assembly, and I put my IN on the Left, and my hex plug on the Right.

*cry*

And I JUST snapped one of my valves, too, so I have to buy a new ball valve and a new 90*deg fitting.

I shoulda bought a prefab one. I suck at DIY. I don't even own a bench vise. I spent an hour trying to get the regulators together tightly enough.



sorry for the thread rez. I just needed to explode a little.

Ok, I'm afraid that I must report that I have joined the ranks of those having problems with AS&S regulators. Here's my info, please feel free to make any comment you think will help.

Up until this weekend I had one regulator, on 5 way manifold, and 4 checked gas-out to ball lock connectors. No leaks, 4 kegs under pressure since about a year ago. Since I recently added soda to my fridge, I wanted to expand my available pressures and purchased 4 used Perlick secondary regulators from American Science and Surplus. To go with that, I purchased 4 new gauges from abibeverage (eBay), three 1/4" brass M-M nipples from Lowes, and 2 more checked NPT->MFL valves. So now, my setup looks just like post #14 except that I have a valve on the left where the gas comes in and my gas-out connections are MFL, not barbed. All threads were liberally coated with paste pipe thread sealant prior to assembly.
Here's where the fun begins.

Sat AM - I installed my new reg bank in fridge checked the MFL fittings with soapy water, and pressurized her. As a test, I shut off the tank and all 4 gas-out valves. Within minutes I noticed that #2 and #4 (left to right) were dropping slowly. Since at least one of my valves had turned during assembly, I suspect they weren't tight enough.

Sat PM - I pulled the assembly out, benched it, and turned *all* fitting at least one more revolution. Now, they are definitely NOT too loose. If anything, they are too tight. Put her on the bench and gassed her up. While I let her sit, I applied more pipe sealant around all the junctions for good measure. I noticed that couple of gauges (not just 2&4) dropped, but only when they were turned away from me. I guessed that for whatever reason, they didn't like being rotated. So I turned it face up, pressurized the primary to 28psi, all secondaries to 20psi, closed the tank, and let her sit still. 1hr later, all gauges were still at 20psi. So I dumped the system and repeated the exercise. Same results. Happy that I had a simple seal problem, I reinstalled her and pressurized the system, being careful to close tank before retiring.

Sun AM - I checked the system and found the primary gauge at 15psi, gauge #1,3,&4 at 10psi (as expected), 2 at 15psi. Repeated exercise closing the valve to the primary gas buss and all gas-out. Returned 2 hours later to find primary line at 28psi (as left), #2&3 at 0, #1 & 4 at 10psi (as set).

Sun PM1 - Repressurized system, closed tank and all valves (again). 2hrs later found the primary gauge still at 28psi, gauge #1 at 10psi (as expected), 2,3,4 at 0psi.

Sun PM2 - Repressurized system, closed tank and all valves (again). 2hrs later found the primary gauge still at 28psi, gauge #1,4 at 10psi (as expected), 2,3 at 0psi.

Sun PM3 - Repressurized system. Opened tank and all valves. Returned 2 hours later to find primary line at 28psi, 2nd gauges as expected. Closing all valves now.
EDIT: After 7 minutes #1,3,4 are at 12psi (normal), #2 is at 5psi, primary is normal at 28psi.
EDIT: After 80 minutes #1 is still at 12psi (normal), #2,3,4 are at 0 psi. primary is normal at 28psi.
EDIT: After 3 hrs #1 is still at 12psi (normal), #2,3,4 are at 0 psi. primary is normal at 28psi.
EDIT: After 10 hrs #1,2,3,4 are at 0 psi. primary is normal at 28psi.

What I know
* Nothing leaked on the last bench test
* The gas-out lines, crimps, and connectors are not likely the problem as they have been in service, and the leaks still happen with them valved out.
* It's not the tank nut, the primary regulator, the hose into the fridge, the flare fitting into the regs, or the 1st valve (up to the ball) as the primary line never looses pressure when the gas-in to the manifold is closed.
* The #1 regulator is the only one that does not ever appear to leak down. It has a NPT-MFL valve that is not checked.
* The #2 regulator seems to leak down every time. It's also the only one at 25psi.
* The #3 and #4 seems to leak or not leak somewhat randomly.

Bump
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Shameless 2nd bump

I hooked mine up last night (been out of CO2) and have a similar problem.


(In to barb on left, hex plug on far right)

I applied pressure with ball valves closed, shut off the tank, and walked away. Within 10 minutes, regulator #1 was down to 0psi. Within another 45 minutes, regulator #2 was down to 0psi. #3 appears to be doing okay.

I don't know what I'm going to do. This thing is a pain in the arse to dis and reassemble, and my lack of a bench vise makes things really frustrating.

Mine is the same except add a valve where your input barb is. If I close it, line pressure from tank to input valve stays at 28psi for days. Open that input valve, and the system leaks down...

What really makes me mad is mine works on the bench with all valves closed. I'm beginning to think these regs are very flaky WRT temperature.... Or perhaps they need high pressure (400psi+) to function properly. As a gamble I left the gas on last night to see if maintaining input pressure had something to do with it. Woke up to a dead tank...

At this point, I'm about to junk the AS&S regs and go back to a single reg with a manifold. That worked without incident for 7 years...

Ok, after several busted knuckles, stripped wrench faces, gouged pipe and valves, much cursing, disassembly, pipe dope removal, teflon tape application, etc., etc. the 4 bank AS&S regulator assembly is back together. I found one tiny leak at the #2 gauge connection, but nothing to account for the erratic pressure losses in the other 3 regulators secondaries. I bench tested for 24 hours with tiny variations +/-, but no significant negative loss. No visible leaks using soapy water and/or kids bubble solution. Now it's back into the fridge to see if it behaves in colder climates. Unfortunately, it'll take a few days as it worked fine on the bench before and then misbehaved in the fridge.

I'll keep posting in case someone else is interested.

Chriso said:

I applied pressure with ball valves closed, shut off the tank, and walked away. Within 10 minutes, regulator #1 was down to 0psi. Within another 45 minutes, regulator #2 was down to 0psi. #3 appears to be doing okay.

Click to expand...

Based on bench testing, it appears these regulators behavior with 0 primary (input) pressure is undefined. Sometimes they maintain secondary pressure, sometimes they back-bleed and lose secondary pressure. I've seen one drop instantly on primary depressurization, and the others drop at apparently random times, some quite a long time (up to 1hr+) after the primary pressure has dropped to zero.

I'll be doing the same soon - I just need to find someone with a bench vise, so I can get this f*ing thing back apart. (I think my parents have one) I'll post back when I'm done too.

We can beat this thing. We gotta.

I wonder if Jester fixed his leak. He was having problems with his AS&S regs too.

I put mine back in the fridge and despite zero leaks and nopressure drop on the bench, #2 will not hold pressure if the supply is cut off. 1,3,4 are set at 10psi. #2 drops fairly rapidly to 10psi and holds there.

I suspect that when the supply is removed, the gas in the primary side cools (and shrinks) dropping the primary pressure. #2 then backfeeds until pri/sec pressures are balanced. That should yield pressure >10psi and < 25psi, but that's not the case. A leak should yield a continuously dropping pressure, but that's not the case either. Continually changing fault behavior is a big part of the problem isolating the issue.

Right now, my bottle is down to all gas (~500-550psi warm). So I'm charging the whole system (kegs and all) to make sure that everything is saturated, chilled, and not re-carbing from lowered pressures. If so, the bottles primary pressure should drop and then stabilize. If it continues to empty, then I know I still have a leak some where. Why that leak manifests itself only in cold temperature is baffling.

Step next will be to make a gauge on a "T" with valves and MFL fittings on the input/output. I'll start inserting that places and alternately opening/closing the valves until I can isolate where the pressure drop is occurring. If that fails, I'll break this reg bank apart and feed each regulator separately with a shutoff valve so I can isolate each regulator independently.

Chriso said:

I wonder if Jester fixed his leak. He was having problems with his AS&S regs too.

Click to expand...

Knock on wood, yes it is fixed. The safety valve on my primary kept releasing on it's own. Found this out while pressure testing it on the kitchen counter. So far, the AS&S regs are still working.

Last night I found a small leak after the #3 ball valve where forward closure (with MFL threads) meets the valve body. The thread locker/sealant must have gotten cracked during re-assembly. Disassembled, cleaned, new sealant, re-assembled. No leaks found.

Now quite frustrated with this thing (and no beer on tap), I put the whole regulator bank under water and pressurized it (pressurized pri 28psi, 12-25-9-11 sec). Then I stared at it like an idiot in a trance for 1/2hr. Not one single bubble of any size appeared. So I removed it, dried it off, and set it on the kitchen counter for an 1+hrs. ZERO changes in pressure. Feeling successful (finally) I went to bed and left it there. This morning I woke up to gauges that had dropped to 5, 15, 7, 5 psi. Then as I watched #2 dropped another 5 psi (15->10) in a split second.

I think I'm quite done with these regulators. I've got at least 20 hours in this bank so far, and cannot find any rhyme or reason for the pressure losses.

I got these same pieces of crap and I too and done messing with them. They are junk and I would not recommend buying them to anyone. I cannot see any leaks with the setup sitting in a bucket of water, but it slowly leaks down every time and I am sick and tired of this crap. They are going in the garbage.