Duotight fittings cracking

[Jtvann]

Checking in to see if any of you are noticing your duotight fittings cracking around the collar. Quite a few of mine are. It doesnt seem to be affecting the performance in any way, but the majority of them have distinct cracks.

 

[RiverCityBrewer]

I checked mine and don't see any issues so far, have about 20 fittings of various types. They have been in use for about 9 months now. Are you cleaning them? If so, how?

 

[Jtvann]

Usually just clean in plain hot water, rinsing under the sink. Then spray with starsan

 

[S-Met]

Checking in to see if any of you are noticing your duotight fittings cracking around the collar. Quite a few of mine are. It doesnt seem to be affecting the performance in any way, but the majority of them have distinct cracks.

How/where are they being used? Wondering if they are under stress or high vibration.

 

[Jtvann]

I've got them plumbed into the gas and hydraulic lines on my excavator ...

What stressful or high vibration type environment can these things even be used for?

I use them for beer and gas lines like everyone else around here.

 

[RiverCityBrewer]

Bizarre for sure... my first thought is chemical incompatibility with phosphoric acid, but that theory would only work if that outer piece is different material than the rest of it. Curious what Kegland says if you send them some pics/info.

 

[RiverCityBrewer]

Hmm, says they are made from acetal plastic... chemical compatibility with phosphoric acid is poor per this chart. Granted mixed StarSan is pretty low concentration, but given your experience I would say perhaps it is enough to degrade them over time.

Edit: Also per the chart it says chlorinated water will damage them, so soaking in tap water or star san mixed with tap water is probably bad.

 

[Jtvann]

Well they're old enough and cheap enough to just buy more as they go bad. I'm not going to not sanitize them. I use quite a few of them when bottle or kegging direct from my unitank. Was more just curious if I was the only one seeing cracks.

 

[RiverCityBrewer]

Very true about the cost, I keep more than a few on hand as well so I'll see what happens to mine over the next few months.

 

[day_trippr]

The vast majority of my PTC fittings are John Guest and DMfit (both acetal copolymer), but I do have five Duotights on the regulators and gas QDs connected to my keezer. I just checked all of them, as well as all of the others save for the six behind my beer shanks and didn't find a single crack.

Back on November 1st I finished replacing all of the beer and gas lines in my brew space with EVAbarrier tubing and PTC fittings galore.
Fingers crossed any user-induced failures would have happened by now.

btw, the Duotight descriptions I've found state "acetal plastic". Is that shorthand/the same as "acetal copolymer" plastic?

I'd be concerned about dumping a cylinder of gas - or a keg of beer - through a broken adapter...

Cheers!

 

[S-Met]

I've got them plumbed into the gas and hydraulic lines on my excavator ...

What stressful or high vibration type environment can these things even be used for?

I use them for beer and gas lines like everyone else around here.

Expansion and contraction as you pull your taps. If they are flexing on each pull of the tap and hitting a hard surface. Ive not seen it, but not saying it couldn't happen. I have seen wear marks in lines liquid lines from flexing of coils in a friends jockey box. The worm clamps slowly rubbed against eachother. He changed the lines out about every other year just to keep things fresh, so never really bothered him about the wear.

Something similar could happen to the fittings. I'd think it's unlikely, but I also think the cracks you have are equally unlikely.

 

[Jtvann]

After looking across all the fittings that I have, I do think starsan is the culprit. None of the ones in my kegerator are cracked. They have also been in use the longest. I have them on both gas and beverage lines.

The ones that I use for transferring on the cold side from my unitank are the only ones affected. They get sprayed with starsan on every use. I bought them when they hit morebeer, so roughly 1 year. I wouldnt have thought starsan affected them to that extent, but it is possible I guess.

 

[Buckeye_Hydro]

I'd replace those fittings.

 

[Jtvann]

I have decided they next batch, I will be replacing all those fittings. might contact morebeer and see what they say about it.

I decided to be a little rough with them and see where they'd fail. Probably wont get any reimbursement for that one, but I wanted to see what would happen.

That cracked collar is what holds the orings inside. forcing the crack to break, the orings pulled right out. Even cracked, it took a lot of force. They held pressure up to 30 psi. I didn't go any higher than that. The design of these things is great, but I have to say after this to be cautious when using starsan on them.

 

[Buckeye_Hydro]

99% of the quick connect fittings we sell are also acetal.
https://www.buckeyehydro.com/fittings/
Russ

 

[Yesfan]

I'll keep an eye on mine. I had to replace a co2 tank recently due to a leak, but I'm pretty sure it was a flakey poppit vale (universal one) on a recent keg.

I have Duotight on all the beer/gas lines in my keezer. The only thing outside of that is the transfer hose I made when kegging. I do let that line soak in star-san while I am gathering keg(s), scale, co2 tank etc.

 

[Jtvann]

I use a lot of these fittings. I have 3 kegs, so 6 for the ball locks, 3 for the shanks, 3 in line check valves, 3 line couplers going into a keg monitor, 3 going into the gas manifold and one going into the regulator. So 19 total in the kegerator. None of those have any problems.

I use a bunch also for kegging direct from unitank and bottling. Those get sprayed with starsan. Of those, about half have a crack of some sort.

 

[Yesfan]

Guess I'll need to buy some extra to have on hand.