YOKE vs DIN

[El Diablo]

In my personal experience I have witnessed two cases of the O-ring excruding on A-Clamps, and one case of the A clamp being dislodged when the cylinder hit the roof inside a wreck, all of these in water incidents. Funnily enough, on all occasions when in the Red Sea.

The big advantage of DIN is that the O-ring is trapped within the valve. Which makes it almost impossible to extrude the O-ring and the valve particularly resistance to lateral force dislodging it.

I have seen one DIN first stage shear off, the cylinder was dropped off the deck onto the quay from about 6 feet, and hit a rail on the way down. Very lucky the accident wasn't more serious. If the rail had been in a slightly different position, there was potential for shearing the cylinder valve off the cylinder or the handle off the valve.

The A-clamp was originally designed with much lower operating pressures in mind.
The DIN valve was designed for operating at higher operating pressures, 300bar. For the lower 232bar, only five complete threads are required, at the higher 300bar, all seven threads need to be engaged.
Equipment that is only suited for 232bar operation has the thread section reduced to only 5 threads to ensure its not fitted to 300bar cylinders.

By any engineering criteria, the DIN design is better.
Hardly a significant criticism the original A-clamp design is quite old (the 50's I think). At that time, twin hose regulators where the norm and the cylinder pressures where considerably lower.
Demand valves have evolved from the original twin hose single valve design to the two valve design we (generally) use now, with the first stage and second stage. With the advent of the two stage valve, cylinder pressures could increase. With the DIN design, cylinder pressures have further increased to a maximum of 300bar. Although, generally (at least in Europe), the low pressure 232 bar is the general norm.

Thank you.

 

[El Diablo]

I won't be changing my scubapro yoke firsts any time soon. Solid lumps of metal. Never had a problem with them. Bomb proof. I can use any tank I have with them including old pillar valves sidemount as I can bungie to the knob. I can swop out a yoke reg in 20 seconds with gloves. There very versatile. Diving today I noticed a little fizzle of air on one of my 7ltr tanks. The oring has been in constant use for 3 years. All this dangerous yoke oring or entanglement hazard talk is just what it is, talk.

Hi Mac, from your avatar / name I must assume you are close to 60 (I'm 49) so not- so old as to feel threatened by newer technologies. The photo you are posting is from quite an old regulator (Mk5?) therefore pushing you bottles beyond the recommended working pressure doesn't seem to be a very good idea. Regarding Scubapro, I am a fanboy of the brand so with you all of the way. Solid gear for many years.

YOKE is indeed easier to operate with gloves or cold fingers. I already acknowledged that in previous posts.

Next, talking about YOUR bottles, that makes a big difference when it comes to O-ring maintenance. Your own set doesn't get used nowhere as much as the tanks on Dive boats. That's one of the major issues.
With DIN, my O-ring is in MY regulator and not on the rental tanks. The majority of folks rent tanks with O-rings that are overused, poorly maintained and constantly exposed to the elements.

Closing, an O-ring shouldn't be in use for 3 years as you mentioned. Risking a burst for a few cents is not clever IMO.

Dive safe.

 

[Celt]

No the first part of your post is simply untrue. Two reasons:
First its a metal to metal contact area, It's not a joint, and it is easily demonstrated
on repeatable testing to extrude the 0-ring at pressures substantially lower than even that of the DIN 200 configuration.

Put another way your old A clamp design cannot even get close to a hydrostatic test load without extruding the 0-ring. Yet by contrast both the DIN 200 and DIN 300 designs exceed even the hydrostatic test pressure for a given cylinder.

Not withstanding the question of why you would or should exceed the design working pressure of a pressure vessel again a question maybe better on another thread or left to our cave fill clowns.

Your moving the goal posts, For a yoke valve the working pressure is 232bar, the hydro test is 340 bar. There's no one using yoke at 340bar. A yoke valves used at the working pressure it's designed for will not extrude the correct oring. It will extrude an incorrect oring. Obviously a 300bar din will take more pressure than a 232 bar yoke. And they both form a seal exactly the same way. An oring sandwiched between two metal surfaces. Granted if you overpressure a yoke valve the metal yoke itself can stretch and blow the oring.

 

[The Chairman]

Define mission specific solution, Did it involve SEAL team 6 and a big pointy knife. Just asking.

Actually, the knife is a trilobyte. Cave diving is a demanding sport. I didn't approach it lightly, and it has resulted in many gear choices not needed or understood by the average recreational diver.

I obviously don't know when exactly modern DIN started to be commonly accepted in the USA! Do you???

The 50s.

As I previously wrote, you are an Instructor, behave like one. Your weak argumentation isn't flattering your image nor helping your case.

Your oft-repeated admonishment is self-serving and an ad hominem. Even more so when considering the faults in your logic. You keep casting aspersions when none are being thrown your way. Please stop.

However, the truth is that you came as quite arrogant and not very welcoming to a new member

Why? Because I disagree with you? You would have me lie to your face instead? Do we need to stop, hold hands and sing Kum by Yah? Maybe you should grow a thicker skin instead? FWIW, calling someone "arrogant" is a sure sign that your arguments suck. Just saying. Next, you'll be screaming that this is life-saving equipment!!! Yokes, split fins, and sharks, oh my!

See, that's the problem, people get so self immersed in their personal preferences and purchase choices that they ignore facts.

This is a problem. You see yourself as an "expert" on DIN. So, how long have you been diving? You have yet to present a single study showing us just how much safer DIN is over yoke. Not one. Not even a reference to one. Where are the people being hurt by a failing yoke valve? DAN doesn't even have a category for that. Are they arrogant for not supporting your position? You've convinced yourself, but not many others... even those of us who dive DIN.

DIN is merely a tool. There are other tools in my collection. Many other tools. Most tools work if used properly and within their limits. It's like you calling a Phillips screwdriver safer than a slotted one. If you misuse it, you might stick it through your Left index finger as I have done. I didn't blame the tool when I did that: I blamed me. It's almost never the tool's fault. Misusing the Philips would result in the same injury as far as I'm concerned. I grew some skills even as I broke my finger.

I've seen failures on both a-frame and DIN. Multiple failures from multiple divers. Almost all of the failures could be easily attributed to neglect and/or damaged parts. Hell, it might be "all", but I've seen a metric butt tonne of failures, and I can't remember all of them. I have yet to see anyone suffer an injury because they were diving a yoke. Ever. I would call that an admiral safety record.

I get that diving is a passionate sport. I've seen the debates over mono-blade vs split fins vs free dive fins, BPW vs Back Inflate vs Poodle jacket, DIR vs all the training agencies, this vs that, and so on. Often the passion is fueled by a divine revelation where a user has decided that they are on a mission from God to save us from ourselves. Meh. Without any studies showing that yokes result in more injuries, I just see your rants as Chicken Littleisms. Like making a mountain out of a molehill. You know, like yokes, and split fins, and sharks, oh my!!!

Older members have a stronger voice than the rest.

There are old divers.
There are bold divers.
There are no old, bold divers.

After 50+ years of diving (longer than you've been alive), I have never been bent. After adopting the SPG, I have never run out of air. The first 10 plus years of diving were without the benefit of a BCD or even certification. Do you really think that all of my experience means nothing? Safe diving is no accident. My big takeaways from all those years?

There are many, equally safe ways to dive.
Neglect is the biggest problem, not gear.

It's never the gear]​

Gear has never solved skills/experience issues.
My lungs are the best BCD.
Experience and treachery almost always overcome youth and passion. ​

 

[Celt]

Hi Mac, from your avatar / name I must assume you are close to 60 (I'm 49) so not- so old as to feel threatened by newer technologies. The photo you are posting is from quite an old regulator (Mk5?) therefore pushing you bottles beyond the recommended working pressure doesn't seem to be a very good idea. Regarding Scubapro, I am a fanboy of the brand so with you all of the way. Solid gear for many years.

YOKE is indeed easier to operate with gloves or cold fingers. I already acknowledged that in previous posts.

Next, talking about YOUR bottles, that makes a big difference when it comes to O-ring maintenance. Your own set doesn't get used nowhere as much as the tanks on Dive boats. That's one of the major issues.
With DIN, my O-ring is in MY regulator and not on the rental tanks. The majority of folks rent tanks with O-rings that are overused, poorly maintained and constantly exposed to the elements.

Closing, an O-ring shouldn't be in use for 3 years as you mentioned. Risking a burst for a few cents is not clever IMO.

Dive safe.

I'm 68 and meticulous about taking care of my gear. I like yoke as it suits the tanks I own. I do have din and yoke valves and poseidon din only tanks. If I wished to use a yoke clamp with them I'd have to use the fitting in the photo. I understand your point about din been more secure in an extreme situation but for normal everyday diving yoke suits me. Yes you need to be careful closing a yoke clamp that it's sitting square on the tank valve and use the right oring. There's some very poor din inserts been made now and I'd imagine din will take over sooner rather than later.

 

[broncobowsher]

Your moving the goal posts, For a yoke valve the working pressure is 232bar, the hydro test is 340 bar. There's no one using yoke at 340bar. A yoke valves used at the working pressure it's designed for will not extrude the correct oring. It will extrude an incorrect oring. Obviously a 300bar din will take more pressure than a 232 bar yoke. And they both form a seal exactly the same way. An oring sandwiched between two metal surfaces. Granted if you overpressure a yoke valve the metal yoke itself can stretch and blow the oring.

But they don't hydro the valve. Valve is removed, cylinder is tested, valve reinstalled after testing is done.
The assumption that a yoke connection is exposed to a 340 bar test is false.

And I skipped the past 4 pages, did I miss anything productive?

 

[Celt]

But they don't hydro the valve. Valve is removed, cylinder is tested, valve reinstalled after testing is done.
The assumption that a yoke connection is exposed to a 340 bar test is false.

And I skipped the past 4 pages, did I miss anything productive?

(Put another way your old A clamp design cannot even get close to a hydrostatic test load without extruding the 0-ring. Yet by contrast both the DIN 200 and DIN 300 designs exceed even the hydrostatic test pressure for a given cylinder.) I was answering the post above. Yep none of my yoke valves or clamps get anywhere near hydro test pressure.

 

[The Chairman]

But they don't hydro the valve.

He didn't say that they did.

 

[Diving Dubai]

My Experience.

I switched to Din at about dive 25. Had all my own tanks which have been abused being thrown into my truck, been on deck of a boat banging and clashing about each month for about 8 years. No out of round valves here (but I can see how in might happen (I use derelin plugs to differentiate between full and empty cylinders but they wont give much if any protection to the valve


I've dived all over Asia - never needed my Yoke adaptor. I have the conversion kits for my regs, in case I was ever going to dive in the US - not worth the hassle

Here is a picture of four different sizes that I grabbed from my tool box.
From left (largest) to right (smallest): 8mm, 1/4 inch, 6mm, 5mm.
View attachment 725548

I haul complete sets on metric and Imperial Allen keys around the world and can almost guarantee I will still come across an insert that has a weird size that I don't have. It's the universe having its fun

 

[Bob DBF]

The A-clamp was originally designed with much lower operating pressures in mind.

Only because that was the pressure used at the time, the yoke was changed as tank pressures increased. As mentioned before, I have a yoke reg designed for 4000# service before DOT regulation changed to DIN only for 3500# and above, probably to prevent someone using a 1800# service from over 3500# pressure which could cause a catastrophic accident rather than just blowing an o-ring.

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