Another keg that won't seal $#@&%!!!

[Yesfan]

I did a brew earlier today. Just a small 4 gallon batch that I wanted to throw in a keg to pressure ferment. For those that pressure ferment, what do you do if you have a keg that "passes" just to start leaking after your fill it and pitch the yeast? I can't find the leak anywhere. I pressurize it up to 15psi, just to watch drop slowly to 0. The lid gasket is the thicker white Orings, but I've learned from here those can be more oxygen prone. After a few attempts of trying to seat the lid, reorient it, reseat, etc., I gave in and swapped the Oring out for a black one. Still the same. The brew day was longer than I wanted, now this. If it weren't for some of my better beers coming out of sh!tty brew days, I'd probably quit this hobby.

Just so frustrating..........

 

[mac_1103]

Try a different lid?

 

[Yesfan]

Try a different lid?

I've actually thought about that.......Since I have a bunch of different kegs, I've tried to keep the parts separated.

Screw it.....I guess I'm going to rob from Peter to feed Paul........

 

[mac_1103]

Or maybe stick something under the lid feet to try to get the o-ring to seat better?

 

[Yesfan]

Or maybe stick something under the lid feet to try to get the o-ring to seat better?

I swapped lids from a recently kicked keg (that still had pressure). If that doesn't work, I'll stick something under the lid as you mentioned (a penny?) or I'll clean/sanitize the keg that held pressure and transfer to it.

Sucks as the current keg held pressure from the previous batch :head smack:

 

[ba-brewer]

How long does it take to lose pressure?

If it is fairly quick it is a leak, if it takes a while it may just be being absorbed by the beer.

 

[tracer bullet]

I've found that my universal posts are a bit longer than my old original keg posts. So when I put them on, I get them tightened down, but later have minor leaks. It turns out they seem tight because they bottomed out against the keg itself - not because the dip-tube O-ring is actually compressed. You might want to have a look there, might be happening to you as well?

 

[IslandLizard]

I've found that my universal posts are a bit longer than my old original keg posts. So when I put them on, I get them tightened down, but later have minor leaks. It turns out they seem tight because they bottomed out against the keg itself - not because the dip-tube O-ring is actually compressed. You might want to have a look there, might be happening to you as well?

Have you tried doubling up the diptube o-ring?
Or using an original diptube o-ring?
Those original diptube o-rings are almost double height, with a groove in the middle. Their profile more squarish too, with an almost flat top and bottom.

Another thought, add a stainless washer under the diptube flange or perhaps better, underneath the o-ring. Just to add more material between the flange and the post stub, for better compression and thus a more positive seal.

 

[tracer bullet]

Those original diptube o-rings are almost double height, with a groove in the middle. Their profile more squarish too, with an almost flat top and bottom.

Interesting, do you have a link or an example? I've not seen that before.

It could help the OP too of course. If you're replying more to me, I do think the posts played a role. Skip to post 48 here for a picture example: Extra tall ball lock posts or connectors?

 

[Broken Crow]

@tracer bullet mentioned universal poppets... On one of my kegs it not only sticks up a bit higher, but has some side-to-side play and has twice started to leak until I pushed it down and up a couple times to get it exactly centered. I've also had something similar recently occur with the PRV on one of my cheap Chinese baby kegs..it began to leak when touched and had to be pulled a few times to seal.(I just bought a replacement)

 

[day_trippr]

Five of the classic poppets used on cornelius style kegs.
Note the different spans from the tips of their legs to the top of their O-rings.

The coil spring used on a "universal" poppet that works in place of number 4, for instance, might be too tall to compress enough to allow a QD with a max length plunger to latch on a post using poppet number 2, requiring trimming a loop or two off the spring...

Cheers!

 

[Broken Crow]

Five of the classic poppets used on cornelius style kegs.
Note the different spans from the tips of their legs to the top of their O-rings.

View attachment 835491

The coil spring used on a "universal" poppet that works in place of number 4, for instance, might be too tall to compress enough to allow a QD with a max length plunger to latch on a post using poppet number 2, requiring trimming a loop or two off the spring...

Cheers!

Just a quick Thanks! ..a year or so ago you provided links where to buy those and it allowed me to correctly identify my poppets and so far have been able to get replacements for 3 of the 4 kegs that need them...no more hassles!
I confer on you the honourary title; "Master of Poppets"

 

[beren]

Or maybe stick something under the lid feet to try to get the o-ring to seat better?

The feet don't make the seal, pressure does. maybe some keg lube on the o ring?

 

[camonick]

Five of the classic poppets used on cornelius style kegs.
Note the different spans from the tips of their legs to the top of their O-rings.

View attachment 835491

The coil spring used on a "universal" poppet that works in place of number 4, for instance, might be too tall to compress enough to allow a QD with a max length plunger to latch on a post using poppet number 2, requiring trimming a loop or two off the spring...

Cheers!

And for those reading this, #4 is the one *usually* found in pin lock posts.

 

[mac_1103]

The feet don't make the seal, pressure does. maybe some keg lube on the o ring?

The feet push the o-ring up against the inside of the keg. If the o-ring isn't tight enough to the keg, all the pressure in the world won't make it seal.

 

[Yesfan]

....................I confer on you the honourary title; "Master of Poppets"

"Pub crawling faster
Day_tripp's your master
Your gas flows faster
Day_tripp's your master, master

Master of poppets, he's pulling your springs
Closing your valves you wished you had cleaned.

Master!, Master!"

* cue epic guitar solo *

 

[Yesfan]

On a serious note, I think I'm going to clean/sanitize one of my good kegs and transfer this beer. I'm still losing pressure in this keg.

I have one that won't hold, so this will be a good time to test my empties and do some repairs. I have some extra post/diptube Orings. The large bail Orings are what I'm worried about if the leak is there. Those are either going to seal or not.

 

[ba-brewer]

These fixed a few kegs that I had that did not seal well with low pressure.
Oversize Keg Lid Sealing 'O' Ring

 

[Biggz1313]

On a serious note, I think I'm going to clean/sanitize one of my good kegs and transfer this beer. I'm still losing pressure in this keg.

I have one that won't hold, so this will be a good time to test my empties and do some repairs. I have some extra post/diptube Orings. The large bail Orings are what I'm worried about if the leak is there. Those are either going to seal or not.

Have you used some star san to try and identify where the leak is coming from? It could be either post, the lid or even the PRV valve. Make sure you don't have some hop debris on the oring of your PRV valve, I've seen that happen before and it's maddening.

 

[tracer bullet]

Have you used some star san to try and identify where the leak is coming from?

Agreed! 2 birds, one stone. Save this one and avoid a transfer, as well as fix the leak you'd be tracking down later anyhow once it was empty.

 

[mac_1103]

These fixed a few kegs that I had that did not seal well with low pressure.
Oversize Keg Lid Sealing 'O' Ring

Worked for me as well.

 

[Yesfan]

Found my leak. It's the gas post. I can faintly hear it. When I wiggle the disconnect, I hear it just a bit more. So I torgued the post down a little more snug. I didn't Hulk out on it or anything. No change. So I took the post off to inspect the dip tube Oring. It looks like one of those flattish ones that Island Lizard alluded to. I swapped out the Oring just to see and if I had the same issue. Yep, still no changes.

While some of my kegs have universal posts, this one doesn't but I did try a universal poppet and I'm going to check later to see if the pressure is still dropping. Thanks for the heads up @tracer bullet on the universal posts. I keep an eye on mine that have them.

The funny thing is, I can hear the gas seeping around the post if it has a disconnect on it. I don't hear it with the disconnect off. If I find I still have a leak, do you think it would hurt to double up on the dip tube Oring? That's about the only thing I haven't done yet,

Btw, I appreciate the help gang.

 

[ba-brewer]

If it leaks with the disconnect attached it sound like the post Oring.

 

[tracer bullet]

If it leaks with the disconnect attached it sound like the post Oring.

Yep, or the disconnect itself. crack in the plastic or something. Getting closer!

 

[day_trippr]

I would not discount the pressure applied to the poppet by a QD causing the post to "lift" causing the dip tube O-ring to lose seal...to something.

Is there a chance that this post is not the correct thread? Posts should never wobble, but if one is using the wrong post for the threaded riser...

Cheers!

 

[tracer bullet]

causing the dip tube O-ring to lose seal...to something.

https://www.homebrewtalk.com/thread...sts-or-connectors.729594/page-2#post-10317356
Different thread and subject, but if you see the picture on the right it's a proper post and that flat vertical section is what the O-ring seals against. It just barely hits it when the post is loose, and as the post is tightened the O-ring squishes out under the dip tube flange and contacts the post in this location. It's why I mentioned the length of the post as an issue, if it bottoms out against the keg, you'll think the O-ring is squished tight but it may not be (because the post bottomed out on the keg and didn't get a chance to go down far enough to have the O-ring become compressed.

Hope that made sense.

 

[Broken Crow]

When I wiggle the disconnect, I hear it just a bit more.

Just out of curiosity; What type/make of disconnect are you using? Have you tried it with any others?
I've thrown out a few el-cheapo disconnects (including earlier Kegland faux-CMB's) because they were ever so slightly out of spec and leaked... I only buy genuine CMBeckers now.

 

[Yesfan]

@day_trippr @Broken Crow


The post doesn't wobble. It's on there tight. The disconnects are CMB. Both of my Kegland spunding valves have them. I only hear the hiss with either of the spunding valves on there, so I think both of them having cracks is unlikely imo. When I take the valve off, I hear no hissing at all, so this got me thinking.

Last night I pressurized the keg to 15psi and removed the spunding valve for the night. I set it beside the keg and the gauge still showed 15psi. This morning when I got up, the spunding valve still showed 15psi on its gauge. I reattached the valve to the gas post to see if it would drop pressure. The keg still had 15psi as well. Neither the keg or the valve lost pressure. I only lose pressure when attached.

So like @tracer bullet and @IslandLizard mentioned earlier, maybe the issue is with the dip tube Oring. Seems like it has to be that since the only time I'm losing pressure is when a disconnect is attached to the keg. For the record, I don't have universal posts on this particular keg, but I did double up on the Orings, so I'm at a loss there.

I'm three days into fermentation and the active part of it seems to be over. I think I'll just let the keg stay pressurized at 15psi for the time being and keep checking each day. When I get ready to crash it, I may just transfer to another keg if I can't fix the leak by then. Truth be told, I'm afraid to muck with it anymore here on out for fear of oxidation.

 

[camonick]

maybe the issue is with the dip tube Oring. Seems like it has to be that since the only time I'm losing pressure is when a disconnect is attached to the keg

Can’t be the dip tube oring… It would leak whether or not anything is connected. Sounds like a compromised/ undersized post oring to me.

 

[tracer bullet]

Can’t be the dip tube oring… It would leak whether or not anything is connected. Sounds like a compromised/ undersized post oring to me.

Yes, exactly. Hopefully that's what Yesfan meant to say. But this is definitely the case.

(or the disconnect, etc. but not the dip tube or its o-ring)

 

[Yesfan]

Yes, exactly. Hopefully that's what Yesfan meant to say. But this is definitely the case.

(or the disconnect, etc. but not the dip tube or its o-ring)

Nope, I thought it was the diptube o-ring when I last posted. Thanks for the clarification. This is good news if you guys think it's the gas post o-ring. Should be a simple fix.

I bought a bunch of orings for my dip tubes and post back when I started brewing. Someone here posted the Oring sizes from McMaster Carr for kegs, so I bought a bunch of spares. I'll swap the gas post out.

The keg hasn't lost pressure since my last post. In fact, it may have gained 1psi since then. Worst case scenario is for me to remember to unplug the disconnect if there's still a leak if nothing improves.

You all don't know how much I appreciate your help and patience in all this. Wish me luck.

 

[hgearle]

After kegging my beer this week and pressurizing to 30psi to seal, the next day there was beer on the floor. It turns out the liquid out-post fitting was loose. I usually tighten down the fittings pretty good, but I gave them both a good hard bang with a wrench and the leak stopped.

So, change all gaskets with new, then make sure everything is properly tightened. Consider using keg lube on the rubber fittings.

 

[Dland]

When working with old kegs, including ones that have just been "refurbished", it is good to test pressurize with air or Co2 to check seals, before adding beer.

A pressure gauge on gas post is easy to set up, and can later be used to measure keg pressure for D rest activity, spunding, etc. It is a simple step, easy to do, and can save aggravation.

 

[tracer bullet]

So, change all gaskets with new, then make sure everything is properly tightened. Consider using keg lube on the rubber fittings.

And, in my case at least, make sure the posts aren't bottoming out on the keg itself, feeling like they are tight, when they really haven't compressed the o-rings very much at all.

When the o-ring is working properly (meaning all the other parts are as well), you can almost get away with finger tight. I don't suggest it, but am trying to say it takes very little wrench force to compress the o-ring and have it seal. I will of course wrench it down, but you definitely don't need to go to the point where it's difficult to turn any further.

(I'm not saying you did this BTW just seemed like a thing to mention, that I think is related)

 

[Yesfan]

And, in my case at least, make sure the posts aren't bottoming out on the keg itself, feeling like they are tight, when they really haven't compressed the o-rings very much at all.

When the o-ring is working properly (meaning all the other parts are as well), you can almost get away with finger tight. I don't suggest it, but am trying to say it takes very little wrench force to compress the o-ring and have it seal. I will of course wrench it down, but you definitely don't need to go to the point where it's difficult to turn any further.

(I'm not saying you did this BTW just seemed like a thing to mention, that I think is related)

In your case with the posts bottoming out, do you think it's a good idea to double up on the dip tube o-ring?

 

[tracer bullet]

In your case with the posts bottoming out, do you think it's a good idea to double up on the dip tube o-ring?

I don't see how that would help. I ended up machining the posts down on a lathe, and later buying new ones that were shorter and better to start with. I linked a thread earlier I made trying to figure out how to extend a post. I ultimately didn't do it but did show some pictures and info on how this stuff fits together.

 

[mac_1103]

In your case with the posts bottoming out, do you think it's a good idea to double up on the dip tube o-ring?

It's been hit or miss for me. Worked perfectly a time or two, but still bottomed out one time, and couldn't get the post on another time.

 

[pvtpublic]

So, why don't you submerge them in the tub, or spray everything with starsan/soapy water? You'll find your leak real quick

 

[Yesfan]

I don't see how that would help. I ended up machining the posts down on a lathe, and later buying new ones that were shorter and better to start with. I linked a thread earlier I made trying to figure out how to extend a post. I ultimately didn't do it but did show some pictures and info on how this stuff fits together.

Do you have a link to the shorter ones? What would I look for if I have to go that route?

 

[tracer bullet]

I got my replacements from Brew Hardware:

https://www.brewhardware.com/product_p/ballpostgas1932.htm
https://www.brewhardware.com/product_p/ballpostliquid1932.htm
I guess they aren't technically shorter, but the threads aren't cut as deep as my earlier fittings, resulting in the same effect where they don't bottom out. The shape inside too, where the O-ring lands, is also different than my earlier fittings, and there's more "flat" for them to hit. When you screw the Brew Hardware fittings in place you can actually feel the O-ring contacting them slightly, even before any tightening occurs. And when the O-ring compresses it his a flat area, not just threads.

When I say "earlier fittings" I'm talking generic fittings form Amazon, the universal replacements. I ditched every last one of them. I've got the Brew Hardware fitting son everything now. These are the ones I mentioned are working properly for me across the board and even just finger tight creates a seal. When you wrench them into place you don't have to go until they can't be turned anymore, somethign just past snug is plenty.