Din vs Yoke

[Divescape]

I have dived both. One a Titan yoke the other a MK25 Din which i converted to DIN. Why i did was simple. i do not like to rely on other peoples O rings. i was loosing a couple of o-rings a month into rental tanks where i took one look at the o-ring on the valve and replaced it. Ok this is not at all a significant cost, but i know the state of the o-ring on my reg and am not reliant on a factor out of my control. Just my 2c as DIN is widely available for us.

 

[Lorenzoid]

Isn't this whole discussion of which is "more secure" in a mechanical sense--DIN connection or yoke connection--a red herring as far as most of us who are not cave or wreck divers are concerned? Mechanical strength of the connection is only a consideration for divers who want an extra margin of safety against the possibility that they might bang their valves on cave ceilings or wrecks. For us rec divers, it is a NON-ISSUE. Yoke connections are not known to fail.*

*Granted, anything can fail, but I suspect that an incident in which a yoke valve connection was physically damaged is exceedingly rare--the vast majority of us will never even hear of one. You probably have a greater chance of being bitten by a shark.

 

[dfx]

In my short 4 years experiece in diving, I see more leaky/bubbles from a DIN connetion than a Yoke connection in water. Granted none are seriously enough to cause a dive. Just stating my observations.

Really? I've had the exact opposite experience. I've had a yoke o-ring extrude on me and plenty of leaky yoke connections. Never seen any such problems with a DIN. Of course the DIN o-ring is my own and I know what condition it's in and how well or badly I treat it.

 

[kwinter]

all the bottles you will rent will have 200din connections and the 300 din stands more than the half way out, this is what you call a more secure connection?

200 bar DIN = 5 threads
300 bar DIN = 7 threads

200 bar valve = 1" depth
300 bar valve = 1.4" depth

Please explain how a 300 bar reg in a 200 bar valve will stick out half way. At most it is 28.5%. Keep in mind that I am a math professor as well as a tech/rebreather diver. And also keep in mind that tech/rebreather divers use DIN regs (mostly 300 bar) in DIN valves (mostly 200 bar) all the time in the most challenging conditions. Yes, it is absolutely more secure than a yoke connection. Without question.

For reference: DIN Scuba Fittings

 

[Omisson]

well i don't think so sir.
if you buy a new scubapro mk 25, it will come with an din adapter for 4500PSI (300BAR)
most of the tanks for "recreational" diving are for 3000 PSI (200BAR)

see the difference here:
View attachment 182481

are you sure that this connection (din 4500 PSI to an 3000PSI valve)
is this a better connection than INT?

not for me.
I you touch with this connection in a cave or something the proability to brake is the same or more than with INT.

And don't understand me wrong we have 2 Tanks at home 1 with 4500PSI with his mk25 DIN and it fits perfectly
and one INT for the 3000PSI tank.

As a matter of simple mechanics, the connection made by a threaded locking collar is far superior to a clamped on collar.

It's not more complicated than the difference between a screw and a nail- which holds together better?

And again, where you are diving and what type of diving you do dictates the market share of din or yoke set ups BUT most modern yoke valves coming out are now convertible, so I'd imagine eventually both will be equally available in the US/carribean... Europe will likely stay a DIN market....


Dan-O

Sent from my iPad using Tapatalk 2

 

[ams511]

Tell me where in that post (or any other) that I said divers commonly fill their tanks over 3442 (or 3500) psi. HP tanks are not permitted an overfill. Very few places fill over 3500 (after temp settles) unless you're talking about fiber wrapped tanks like those used by fire departments. Those get filled to 4500, but most places don't have that capacity.

Just grow a pair and admit you were wrong. The reasons tech divers use DIN regs has nothing to do with their tank pressures.

Why don't you grow a brain and admit you are wrong? If you clicked the link then you will find, "Most LP steel tanks still in use are 2400 psi with a 10% overfill allowed, for a total of 2640. But folks give them cave fills to 3000-3500 all the time." Perhaps you should consult with your colleagues in the English department to debate if "all the time" is synonymous with "commonly". I think most folks would agree they are so yes you said it. As usual your posts are argumentative and full of hot air and have nothing to do with the topic.

Also I don't know where you are getting this magical 3442 number from. Older yokes on first stages were only rated to 2400 psi maybe less. They got stronger to match higher tank pressures but DIN fittings could always withstand a higher pressure. So pressure may not be a limiting factor currently, it was in the past. I also gave other reasons why tech divers use DIN fittings which you neglected to comment on so I assume you agree with those.

 

[kwinter]

Why don't you grow a brain and admit you are wrong? If you clicked the link then you will find, "Most LP steel tanks still in use are 2400 psi with a 10% overfill allowed, for a total of 2640. But folks give them cave fills to 3000-3500 all the time." Perhaps you should consult with your colleagues in the English department to debate if "all the time" is synonymous with "commonly". I think most folks would agree they are so yes you said it. As usual your posts are argumentative and full of hot air and have nothing to do with the topic.

Also I don't know where you are getting this magical 3442 number from. Older yokes on first stages were only rated to 2400 psi maybe less. They got stronger to match higher tank pressures but DIN fittings could always withstand a higher pressure. So pressure may not be a limiting factor currently, it was in the past. I also gave other reasons why tech divers use DIN fittings which you neglected to comment on so I assume you agree with those.

Read it again. In one thread I said that tech divers rarely fill their tanks over 3442. In the other thread that you pointed out I said that folks do cave fills on their LP tanks to 3000-3500. I will now point out to you that 3442 is in the range of 3000-3500. I said the exact same thing in both threads. Tech divers routinely fill to 3442 or 3500, but almost never above that. But you accused me of saying something different. Unless you are picking fly**** out of the pepper by pointing to the difference between 3442 and 3500, which I equate to virtually the same thing. This was all in response to the original comment about tech divers using higher pressure like 4500 psi that can't be handled by yoke attachments. Yes, there are a few fiber wrapped tanks that use that pressure, and they are more common in Europe (but still rare). Very few divers here, tech or otherwise, use pressures above what current yoke attachments are rated for.

As for the magical number of 3442, look on any new HP tank. Old 7/8 skinny neck HP tanks were rated to 3500 psi. Technically, that exceeded the allowed pressure for yoke attachments at 232 bar, so they required 300 bar valves. Some Japanese spun HP tanks with standard 3/4 inch necks were made recently and still carried a 3500 psi marking, but I was told they changed that for XS Scuba and are now marked 3442. The difference is relatively minor, but that's what bureaucratic mumbo jumbo is about. And you are correct that very old yoke attachments were made with far less pressure in mind. LP steel tanks used to be 1800 psi. Then 2050 and 2400, etc. As tank pressures increased, manufacturers changed their yokes. I remember upgrading my first Scubapro MK5 from the '70s to a stronger yoke. I still have the original in my shop. It is clearly much thinner metal and would not withstand even 3000 psi. But that was a long time ago. Modern yokes are made to withstand 232 bar; hence the 3442 marking on tanks. No one in this thread was talking about using a 40 year old yoke reg rated for 2400 psi. If you want to read more before you start spewing garbage, try here. DIN Scuba Fittings

I might have agreed with some of the other things you said, but you lost all credibility with a statement that the reason tech divers use DIN is because they use higher pressure tanks than what a yoke can handle. Modern yoke capacity is 3442 psi. There are reasons that tech divers use DIN. Tank pressure is not one of them. Period.

 

[dive_more]

200 bar DIN = 5 threads
300 bar DIN = 7 threads

200 bar valve = 1" depth
300 bar valve = 1.4" depth

Please explain how a 300 bar reg in a 200 bar valve will stick out half way. At most it is 28.5%. Keep in mind that I am a math professor as well as a tech/rebreather diver. And also keep in mind that tech/rebreather divers use DIN regs (mostly 300 bar) in DIN valves (mostly 200 bar) all the time in the most challenging conditions. Yes, it is absolutely more secure than a yoke connection. Without question.

For reference: DIN Scuba Fittings

Hi, nothing better than an image for that!

this is how an MK25 fits on a 232 bar valve


and this is how the int insertion fits in the 300bar tank


yes you are right but it stands not the half way out but almost ,
the din connection is made of brass not steel

as a technical (an rebreather) diver you agree with me to avoid every failure point possible, no?
in that way, this connection is not more secure than an INT connection.
(i have nothing against din, i dive both, but its always the same in this INT vs DIN threats, DIN = more secure )

 

[kwinter]

I'm still not sure what you're getting at here. If your concern is with using 300 bar regs in 200 bar valves, rest assured it is done all the time and is extremely secure. The small "fulcrum" created by having a gap of 2 threads is immaterial. The hand wheel doesn't need to bottom out against the face of the valve orifice. The back of the DIN connection must bottom out at the back of the valve. I guaranty it would take much more force to cause a failure of that reg than it would for a yoke attachment. And I have no idea what you are trying to show with the second photo. It looks like a yoke slug put into a 300 bar valve, which can't work and is unsafe.

But if you are really concerned about the DIN regs sticking out, then ask Scubapro if they can retrofit your MK25 with an old school 200 bar fitting. Then you just have to avoid 300 bar valves. Just like you would with a yoke connection.


Please pardon any typos. Sent from my iPhone using Tapatalk

 

[dfx]

in that way, this connection is not more secure than an INT connection.

I don't agree. It takes the entire 5 turns of the wheel to completely screw in (or unscrew) a DIN reg into a 200/230 bar valve. For a yoke on the other hand, it only depends on the size of the dimple on the back of the valve, and most are quite shallow that it only takes what, maybe 2 complete turns of the knob to completely remove the clamp?

And even if the dimple is very deep, the combined contact surface area of the DIN connection is still way higher than anything you'd ever find in a yoke connection. This makes it a much stronger connection. Mind you that I'm not talking about how well the o-ring seals or how much pressure it can withstand, only the strength of the connection itself, and how much force it would need to break that connection.