DUOTIGHT LEAKS......

[franknbeans]

I'm making a list to convert my keezer gas/beer over to this tubing since I need to replace the draft lines anyway (didn't clean them, didn't know any better... ) I thought these were pretty cool setups and remind me of paintball air lines that use the same idea. those quick connects never leaked unless the line wasn't cut straight. Now I'm seeing how many people have leaks.. I'm kinda timid about changing the gas side. The paintball connects were all stainless/chrome so at least they never broke like these seem to be. Maybe I'll hold off with the gas side for now.

 

[Jayjay1976]

I ordered the clips linked above, they came in and I installed them on all my DuoTight fittings. Then I rolled up the extras in the little baggy and went to put them in my small parts bin, and was amazed to find an identical bag, half empty, of the exact same clips leftover from my RO filter install! Good information to know!

IF YOU ALREADY HAVE AN RO FILTER, YOU LIKELY ALREADY HAVE THE CLIPS. LOOK BEFORE YOU BUY!

 

[jddevinn]

I've found that all of my leaks are from cracks in the fittings. I've had the JG version on my beer side for 7+ years without any leaks. This leads me to think that A) the JG fittings are stronger than the duotight or B) (much more likely) I'm afraid of CO2 leaks and therefore installed the duotight fittings too tightly and cracked or stressed almost every one.

I've ordered some more of both but am thinking my issue was all user error. If you install too tightly they will crack.

 

[Tom R]

In case you haven't seen it, Morebeer provides this installation info on their website:
duotight Female Flare Fittings (1).pdf

My kegerator uses 20 of them, no leaks or cracks yet (that I know of).

 

[franknbeans]

In case you haven't seen it, Morebeer provides this installation info on their website:
duotight Female Flare Fittings (1).pdf

My kegerator uses 20 of them, no leaks or cracks yet (that I know of).

DuoTight Female Flare fitting <--link to the .pdf on MoreBeer

 

[Tom R]

Thanks Beans for the link fix.
I'm not exactly a computer or internet power-user.

 

[franknbeans]

No worries, I got ya! I hadn't seen that on the site before, so thank you for sharing.

 

[bartichex]

For those who have leaks, could some of this be due to not seating the hose properly in the fitting? It’s not obvious, and a little counter-intuitive, but the hose needs to be pushed all the way in, and then PULLED back out slightly, in order to engage the collar inside the fitting.

 

[jddevinn]

Almost all of my leaks in the duotights are coming from the body at the seam under the threads even if there are no visible cracks.

Found this one today, the line is going to a fermenter and is at 2.5psi. Marking the leak location and removing to inspect there are no visible cracks. Just leaking at the seam. JG are thicker in this location but I'm still waiting on my shipment of them to try on the CO2 side (I've had on the beer side for 7+ years with no issue.) If they don't work better I'm going back to barbs on the CO2 side and forcing the new lines over them.

 

[Bobby_M]

I promise you all the leaks are due to initial overtightening, later manifesting in stress cracks. Keg lube on the threads and flare tip. Hand tight. Pressurize and look for leaks. If it bubbles, one more 8th turn.

 

[jddevinn]

I promise you all the leaks are due to initial overtightening, later manifesting in stress cracks. Keg lube on the threads and flare tip. Hand tight. Pressurize and look for leaks. If it bubbles, one more 8th turn.

I think so too. But I think it is so easy to overtighten because the material is so thin in this area

 

[tracer bullet]

Random FYI on clamping EVA Barrier tubing to barbs with oetiker clamps:

6mm tube on a 5/16" barb - 11.3 oetiker is just a bit too small, 12.6 fits perfectly
6mm on 1/4" barb - 10.5 just fits, 11.3 is perfect
5mm on 1/4" barb - 10.5 was ideal

These were the #'s on my clamps anyhow, it seems there's a ton out there w/ slightly different numbers.

Hope that helps someone some day.

 

[gnef]

For those using Bev Seal Ultra, John Guest has brass fittings (they are only offered in 1/4" OD and 3/8" OD, IIRC). I've been using 3/8" OD tubing for both gas and beer for many years now. I had been using the acetal John Guest fittings for both gas and beer for many years, and have had a couple failures due to overtightening.

For my gas lines though, I've been changing them over to the brass versions. They are more expensive, but much more durable. I also use these in conjunction with the check valves that go from 1/4" NPT to 1/4" MFL, and use the nylon washer there. I think these are great for the gas side, though I would be nervous about using them on the beer side, so I've kept the beer side with the acetal. I can post pictures if anyone is interested.

 

[day_trippr]

Or...just don't overtighten the fittings - and perhaps avoid Duotight 1/4" FFL connectors outright.
I know you have like 16 tapped kegs and countless (50-60?) more presumably on gas. That's a lot of fittings to spend "brass money" on.

I have a total of 61 1/4" FFL to 8mm OD connectors on just my gas and keg purge systems. All but five of them are JG. No issues after now 14 months in service...

Cheers!

 

[gnef]

Or...just don't overtighten the fittings - and perhaps avoid Duotight 1/4" FFL connectors outright.
I know you have like 16 tapped kegs and countless (50-60?) more presumably on gas. That's a lot of fittings to spend "brass money" on.

I have a total of 61 1/4" FFL to 8mm OD connectors on just my gas and keg purge systems. All but five of them are JG. No issues after now 14 months in service...

Cheers!

Haha, you have a good memory! It is actually only 14 taps on the walk-in. What's crazy, is that amazon's algorithm changed the price one night at like 2am for the packs of 10 of those brass fittings from $45 to about $10, and I bought 4 packs or so (I really should've bought as many as they had available!), so it wasn't too expensive, but I do intend on eventually spending the money to finish out the upgrade for the gas lines. These brass versions are so much more durable.

I've got the manifolds and secondary regulators in the walk-in, but I also have a number of other regulators, manifolds, fittings, etc. so it is a lot of fittings overall, and the reason why I haven't changed over all my gas lines yet - there always seem to be something else more important to spend the money on at the time! Soon though...

 

[day_trippr]

Serendipity can be awesome, but it's an unreliable paradigm
btw - what type of tubing are you using? I'm not seeing any 1/4" FFL to 8mm OD fittings in brass, so I'm guessing you're not using EVABarrier on your gas side yet.

Anyway...even if available, at the apparent regular price of around $5 a pop I'd be looking at $300 for brass connectors.
Hahahahaha! Nope

Cheers

 

[gnef]

Serendipity can be awesome, but it's an unreliable paradigm
btw - what type of tubing are you using? I'm not seeing any 1/4" FFL to 8mm OD fittings in brass, so I'm guessing you're not using EVABarrier on your gas side yet.

Anyway...even if available, at the apparent regular price of around $5 a pop I'd be looking at $300 for brass connectors.
Hahahahaha! Nope

Cheers

Yup, that's why I had said for those using Bev Seal Ultra. I am using their 1/4" ID x 3/8" OD tubing (I also use 650ss flow control faucets for the added restriction, I have a bit of a unique setup).

They are definitely pricey at full price! I will say that once I realized that I needed more, I kept the amazon page up on a tab for months hoping they would randomly drop the price again... it never happened. haha. They really are great to work with though.

 

[day_trippr]

PSA: Do not try to use a hard plastic 8mm OD plug (Duotight) on a 5/16" OD fitting (John Guest). You'll be lucky to ever get that plug out of the socket, and even if you do you'll probably wonder if the socket was damaged and likely replace it on GPs like I just did.

Don't do that...

Cheers!

 

[jddevinn]

I continue to have the fittings fail, in areas that I have't touched lately. I know that the failures are due to over tightening, however, I've had ones fail on quick disconnects that I never use a wrench on. Interestingly the ones that are failing with micro cracks..... I can install on beer lines (just for testing) and they do not leak. I've started to just replace the CO2 side with regular MFL -> barbs.

 

[day_trippr]

Right. It's pretty obvious to me that Duotight 1/4" FFL connectors have a design flaw in the mold geometry that leaves them vulnerable to "excessive" torque - the threshold of which may not be easily determined. I think @Bobby_M's advice to lube the QD (or manifold or shut-off valve) threads and tip, hand-tightening followed by an immersion test, with just slight additional wrench-assisted twist applied should the fitting leak, is good advice, as it will help get to the "just tight enough" state. Hopefully they don't fail after that careful installation...

Cheers!

 

[jddevinn]

I think you are correct. And I've had the JG version on my beer lines for years, including using the same fittings when changing from Ultra 235 vs EVA Barrier. I've lost confidence in using them on the CO2 side. Although the EVA Barrier is much better then the red 'CO2 line'.

I still had all my old lines in storage with other old brewing equipment. Cutting the barbs out and moving over to the EVA Barrier line, using hot water and a swagging tool, did not take nearly as long as I thought it would.

 

[maxr]

Out of curiosity, why use duotight fittings? I have been using standard flare fittings for 15 years and the only leaks that I’ve had are from keg posts. It seems like here and on Reddit there are constantly threads about duotight leaking. Is there some advantage in terms of beer quality?

 

[gnef]

Out of curiosity, why use duotight fittings? I have been using standard flare fittings for 15 years and the only leaks that I’ve had are from keg posts. It seems like here and on Reddit there are constantly threads about duotight leaking. Is there some advantage in terms of beer quality?

To my observation, when many changed to the EVAbarrier line, it was often paired with these duotight fittings (I can't remember if they are the same company though) because of the metric sizes and to make a simple easy to use package. Since so many are using the EVABarrier tubing, it makes sense that there are many that are using these duotight fittings now.

When they came out with them, they were being touted as more leak resistant due to the double o-ring, compared to the single o-ring of the John Guest fittings and other common brands that had been available.

 

[dan46nbrew]

I was recently thinking how expensive JG is and looking for alternatives. Never had a leak though and looks like they are worth the cost, glad I saw this thread.

 

[TenaCJed]

That's a lot of fittings to spend "brass money" on.

Sorry, had to share. Catching up on this thread and when I read this I originally read it as Brass Monkey!!! Of course then the song became stuck in my head as I reread it as I knew brass monkey was not right.

Now back on topic, I replaced all my gas side duotight 1/4" flare fittings back to swivel nuts due to issues with them cracking months after installation. Sure I had one or two in the beginning that I put on too tight as a learning curve. But then I had several that cracked well after the fact. For some issue I have not had any issues on the beer side though. Now I do have other duotight fittings on the gas side that I have had no issues with like in line regulator with gauge, elbows, and check valves.

 

[matt_m]

Wow, almost ordered all the parts to convert over the holidays when everyone was running sales. My biggest hangup was the cost of the new tower shanks to fit the push connects so I never pulled the trigger. Sounds like I should just order the tubing and stick to barbs.

 

[jddevinn]

I had Ultra 235 line for my beer line and the 'regular red CO2 line' for years I swapped both for EVA Barrier lines. Had the JG connectors on the Ultra 235 in the keezer, conditioning fridge, and in several lines I disconnected regularly for kegging and never had an issue with them. The issue I'm seeing is only on the CO2 side.

The duotight is matched with the EVA lines by the manufacturer and resellers. Getting them on a barb isn't hard with a swagging tool and a bit of heat, but is not "consumer friendly"

 

[JAReeves]

Another place to firm up is the regulator / tank connection. I added a .7" flat rubber washer after bleeding a 20# tank down in a week :-(

I just did this with my new CO2 tank-I added a ball-lock post o-ring and it stopped the leak from tank to regulator. A little keg lube kept it in place until I could get the nut tightened to make the seal. I have had to do the same method with the occasional propane tank as well.

 

[teesherv]

I just wanted to report back that after removing, cleaning, and careful tightening of the tail piece AND cutting a new beer line AND installing the little blue clip, I no longer have a leak from the Duotight tail piece. As to which one cured the problem, I couldn't tell you.
I'm referencing back to the first page, 4th or 5th post. Has nothing to do with what this thread morphed into, but I had to complete this.

 

[GoeHaarden]

Replacing my stand up keezer with a stand up fridge and was looking into going JG or Duotight for liquid lines. Obviously the shanks will be through the door, and now I'm a little concerned about leaks with opening/closing of the door.

Anyone use these and Eva lines through a stand up keezer/fridge door? The repetitive movement opening the door has me a little worried now.