New to kegging - question about gas leaks

[Elderfi]

Hey all,

I've recently moved to kegging. I have purchased a Series X keggerator from KegLand. I've set it up following their youtube video. I also watched a few other videos on setting them up too. One video suggested that to check for leaks in your system "give it about 40 psi and come back in a few hours to see how much pressure is in there" I've done that - well I think I have done that. After assembling the keggerator, but before attaching the lines to the kegs, I did the following in order:

1) Turn on gas
2) Twist handle on regulator to get 40 psi on the dial.
3) Twisted back the handle
4) Turned off gas
5) Waited around 2 hours

My PSI dropped from 40 to 39 over this time. So I assume gas is escaping somehow. To investigate matters further, I did a spray test. Where I filled a bottle with soapy water and sprayed all the places the lines have connections to each other (I have three kegs) and where the line connects to the regulator and where the regulator connects to the bottle. Nothing looked like it was leaking.

So is it normal to lose PSI over a few hours, or are there other ways to test my system for leaks?

Thanks

Adam

 

[kadmium]

Hey mate. Not to be rude but that's not a great taste.

Ramping the pressure will often seal a leak that may be present at serving pressures.

The key leak spots I find are the posts on the kegs and the disconnects.

The best way is to get a bucket of water and dip things into it at around 10PSI. Dip the QDs, and any joints etc you can manage into the bucket to check for leaks.

Before fully setting up I would suggest installing check valves they are a life saver for new keggers.

The other option is to mix up some starsan and spray it onto anywhere you can physically dunk in water. Check for bubbles.

To check kegs are leaking, fill them with water and then gas them to 10PSI, leave the QD on, come back a while later and see if its lost pressure.

The issue with filling the lines or kegs with just gas is that minor temp changes change the pressure. That 1PSI drop is probably a function of the temp dropping a degree or two.

 

[Elderfi]

Thanks for the reply - not rude at all! I'm very new to kegging, while it is exciting there is a bit to learn. I've just been watching youtube videos, so I have probably misinterpreted the information. I did do the spray test, I didn't use starsan (the guy on the youtube video advised against it) I used detergent. I think it the surfacant in starsan which is what yields the bubble, so detergent should be a reasonable substitute.

I just gave the whole system a clean, following yet another youtube video. I used PBW, then ran that through the taps, then rinsed with water and ran that through the taps, then ran a litre of starsan mixture through the taps. Everything seems to be functioning well, which is encouraging. I'm going to do a few brews this week, so will have a fortnight or so to get this leak (if there is one) sorted out.

Thanks for the advice!

 

[kadmium]

Hey mate. Not sure why they would recommend against starsan... detergent is not something you want anywhere near beer or beer glasses, as it will destroy the head very fast. Getting detergent into the quick disconnects will allow it into the beer which will cause head issues etc.

I always spray down the posts and QDs right before hooking up the keg so not sure what he's on about. That's only my opinion though, might get different views from different folks.

By all means you have done nothing wrong, just different to what I would recommend. Ensure you thoroughly clean and wipe away anywhere there is detergent that could mix with the beer. 1 drop in a whole keg will ruin the head.

PBW is the way to go, sounds like you got the taps and lines cleaned which is good.

 

[Elderfi]

I think his point was to do with StarSan eroding the plastic of the Duotight fittings. Either way, I’d prefer to replace a fitting every now and then over ruining a batch of beer!


So I did as you suggested, I submerged all the connections I could in a pot of water and looked for bubbles (with the line charged with around 18 psi). I couldn’t detect any leaks – no bubbles in the water. The only connection I couldn’t submerge was the connection to the regulator. I sprayed this with StarSan (mixed at 1.5ml per litre) and tiny bubbles appeared, although not the large bubbles I have seen when watching youtube videos demonstrating this test. I noticed that this connection could be a little tighter, so I tightened it up with a shifter, nothing crazy just until I couldn't tighten it without using a bit of force. The video posted by Kegland suggested not to tighten this too tight - I have attached a photo for reference. The spray test still yielded the small bubbles (see photo).

And somewhat unsurprisingly, the gas in the lines leaked out overnight.

I'm a little at odds as to what to do. Perhaps my Duotight fitting is busted? I also sprayed the regulator connection to the gas tank, and didn't get any bubbles.

Is there anything you can suggest here?

 

[kadmium]

Hey mate. I don't see starsan ruining the fittings as you use it on everything and run it through the lines to sanitise the beer lines etc so I wouldn't worry about that.

I put thread tape on mine, as I have the MK4 reg with the duotight and I found no matter how much I tightened it didn't seal. I think the tolerance of the threads isn't 100% so it gets minor leaking.

Get some blue thread tape from the big green shed and put a few wraps in the opposite direction to what you tighten. That will stop it snagging and bunching up as you tighten it. Should be apples after that!

 

[theSeekerr]

Hey mate. I don't see starsan ruining the fittings as you use it on everything and run it through the lines to sanitise the beer lines etc so I wouldn't worry about that.

This is a very real thing - the particular plastic Duotights are made from hates starsan. It's fine when concentrations are low (like properly made-up starsan in the lines) but if you let the water evaporate the higher acid concentration absolutely destroys the fitting. I'll see if I can dig up a photo of one that I used with Kombucha and then forgot to clean before I put it away...

 

[kadmium]

This is a very real thing - the particular plastic Duotights are made from hates starsan. It's fine when concentrations are low (like properly made-up starsan in the lines) but if you let the water evaporate the higher acid concentration absolutely destroys the fitting. I'll see if I can dig up a photo of one that I used with Kombucha and then forgot to clean before I put it away...

How good is kombucha by the way?

Hm, that's interesting about the duotights. I learned something new I guess! Bit weird cause I spray everything down with starsan, but I don't use duotights on anything other than the spare small bottle and reg. My main setup uses barbs and step clamps

 

[Elderfi]

Hey mate. I don't see starsan ruining the fittings as you use it on everything and run it through the lines to sanitise the beer lines etc so I wouldn't worry about that.

I put thread tape on mine, as I have the MK4 reg with the duotight and I found no matter how much I tightened it didn't seal. I think the tolerance of the threads isn't 100% so it gets minor leaking.

Get some blue thread tape from the big green shed and put a few wraps in the opposite direction to what you tighten. That will stop it snagging and bunching up as you tighten it. Should be apples after that!

I followed this advice and I think I have resolved the issue, the PSI hasn't changed over 4 hours! Hopefully it will be the same tomorrow morning and we can say job done!

Thanks so much for your help - really appreciate it!

 

[BrewLizard]

I'm not sure there's a bullet-proof way to check.

Slow leaks won't bubble Starsan or detergent. While you can dunk disconnects and manifolds in water, you can't dunk them when they are connected to kegs, which is when it really matters.

So that brings us to the static test, where you pressurise it and then turn the gas off at the cylinder valve. if it doesn't drop on the high or low pressure gauges, there's no leak.

Except...when you put a new keg on, it's constantly absorbing CO2 until it equilibrates, so you have no idea whether it's leaking or absorbing gas. And it just so happens that putting a new keg on is the exact time that leaks are high risk, because you've changed what's connected.

Perhaps there's a way to seal the keezer with a CO2 meter inside. If the concentration rises, there's a leak. If not, you're good.

 

[Grmblz]

Just buy John Guest fittings, yes they're expensive but so is a bottle refill, you get what you pay for. I've dumped my duo's, too many problems.

 

[BrewLizard]

Are Duotights just a Chinese knockoff of John Guest fittings?

 

[Grmblz]

Are Duotights just a Chinese knockoff of John Guest fittings?

Yes and no, KL have taken the JG product and "improved" it, JG have one "O" ring duo's have two, in theory it makes for a better seal, the design itself seems to be sound but once again KLs' habit of going cheap, in this case "engineering plastic" whatever the hell that is has led to a fail, some JG's are also "plastic" well lets say not metal, but the material is unaffected by chemicals, seems to be some sort of glass reinforced resin, duo's melt with commonly used ie bleach and now starsan chemicals also the manufacturing tolerances on JG's appear to be a lot better.
When duo's were first released KL put up a vid comparing them to JG's and claiming the duo's were superior, JG called them out on it, the vid was removed and an apology made, that says it all really.
I use a lot of push in fittings, gas, beer, dephlags, condensers etc, and one co2 leak cost me $70 (full bottle now empty) you can buy a lot of JG's (ok well not a LOT) but quite a few for that sort of money, and what price is peace of mind?

 

[kadmium]

Except...when you put a new keg on, it's constantly absorbing CO2 until it equilibrates, so you have no idea whether it's leaking or absorbing gas. And it just so happens that putting a new keg on is the exact time that leaks are high risk, because you've changed what's connected.

When I pre fill my keg with starsan water, I then gas it to 10PSI and chuck the spunding valve on. Being warm, it doesn't absorb the co2 and being full of liquid temp changes don't change the pressure much. Then I can check it in a couple hours and see if the pressure has changed.

 

[mynameisrodney]

This is a very real thing - the particular plastic Duotights are made from hates starsan. It's fine when concentrations are low (like properly made-up starsan in the lines) but if you let the water evaporate the higher acid concentration absolutely destroys the fitting. I'll see if I can dig up a photo of one that I used with Kombucha and then forgot to clean before I put it away...

I always leave starsan in my keg jumper lines etc and havent had an issue. Now I'm not sure whether to be more worried about the fittings failing or that my starsan is no longer effective haha (it is quite a few years old).

 

[kadmium]

I always leave starsan in my keg jumper lines etc and havent had an issue. Now I'm not sure whether to be more worried about the fittings failing or that my starsan is no longer effective haha (it is quite a few years old).

The starsan is years old? Or the fittings?

 

[mynameisrodney]

The starsan, the fittings I've had for ~6 months

 

[kadmium]

The starsan, the fittings I've had for ~6 months

Why would you be using starsan that's years old? Its just water at this point. It lasts a few months at the most

 

[kadmium]

Why would you be using starsan that's years old? Its just water at this point. It lasts a few months at the most

Or do you mean undiluted starsan? In which case it will last a year or two, as long as ph is less than 3

 

[mynameisrodney]

The bottle is years old, but it's freshly mixed.