YOKE vs DIN

[The Chairman]

Think of all this poor schmucks diving yokes AND split fins in shark infested waters?

Yokes, and split fins, and sharks, oh my!!!
Yokes, and split fins, and sharks, oh my!!!
Yokes, and split fins, and sharks, oh my!!!
We're off to see lizards,
The wonderful lizards of Coz...

 

[Celt]

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.

If the oring is the right size the yoke forms a metal to metal joint and it is impossible for the ring to extrude. Also if the oring is to thick it will stop the reg sitting in the grove and could be dislodged. User error can be a problem with yoke regs compared to din. But of course any reg can be damaged. I have poseidon din tanks and regs but find for everyday use the yoke is just to handy.

 

[Celt]

I have personally witnessed several of o'ring extrusions with Yoke connector in the past 5 years or so when tanks had more than 220bar pressure. ALL instances happened in water, above and below surface. the higher the pressure in the tank, the higher the chance for o'ring extrusion for Yoke connector.

I pump all my tanks to 250bar if an oring is trapped in a metal to metal joint it can't extrude.

 

[gbeasley]

No. My hands are usually skilled enough to work with the tools available or i all for another tank. I won't even take the tank vise that I made.

BTW, if I have a very stubborn insert, I'll ask if they have a set of torx. Go to the next size of the one that easily slips in. Tap it in gently with a hammer and then bump it loose with a 3/8" ratchet. Almost as good as an impact driver.

BTW, #2... someone said to use wd-40. Hell no. I don't want to chance breathing those vapors at depth. Yeeeesh!

Old mechanic myself. Love the torx idea. Never thought of that.

 

[The Chairman]

Ç

Old mechanic myself. Love the torx idea. Never thought of that.

Works on sheared off bolts as well and is tougher than most easy-outs. Drill a hole smaller than the torx and tap that puppy in.

 

[The Chairman]

I pump all my tanks to 250bar if an oring is trapped in a metal to metal joint it can't extrude.

True dat!

 

[El Diablo]

I mostly only use DIN because it's just the standard in Europe, h

however I do not agree AT ALL with the statement that din is more resistant to abuse. In case of an emergency an INt reg is super easy to disassemble underwater and alot faster than a din reg. If a tank falls out of a trunk with a din reg 90% of the cases the din reg is bust.

INT regs are bombproof in that regard, you'll never damage the reg, only the int screw.

Yes they leak more often, yes they snag easier, yes in theory and practice it's just a better design to have the o-ring encased.
But if there's one thing that INT excels at it's ease of use, speed of deployment and disconnection and standing abuse.

and let's be honest, the snag hazard isn't caused by the int-post on the valve, but lack of awareness, the horrid hose routing / looping and weird snaggly bits on their harness/bcd's.

Hi Joris,

I partially agree with you and in fact, I already highlighted that YOKE theoretically could be more resistant to abuse than DIN in certain situations and only above water as the valve itself is protected by the clamp.
It is clearly stated in several posts.

However, in +20 years of dealing with YOKE & DIN valves, I've never seen or experienced any DIN failure because of a drop. The DIN does not protrude enough from the valve and the hoses add protection. You will need to drop a DIN reg without its dust cover, without being screwed on a tank and on the threads themselves to damage it... not easy.

I cannot think of any situation where in recreational diving one should remove his 1st stage UW as normally folks don't carry additional stage bottles or regs like in Tec diving for example. For me, the biggest issue with INT valves is the O-ring as also stated previously several times. DIN valves are overall safer than YOKE. I stand by this.

Dive safe.

 

[iain/hsm]

All the operators in Asia are using Yoke as standard.
DIN is NOT safer!
Are you suggesting that all the operators/divers in the world are using unsafe equipment?

Like these dive outfits have a choice?

1. Look most Asia operators are either chicken **** shanty town dive shacks who are totally reliant on the tourist industry to provide a modest cash income or they are group hotel resorts providing a scuba diving experience as part of the package to holiday makers together with fresh towels and clean sheets.

Neither have any say in the matter of what dive equipment is supplied save to choose the lowest bidder tendered product in exchange for a few flags and stickers.

They also have zero choice on what is supplied its part of the load out package from the big scuba suppliers (importer and trade distributor) to the resort area in question.

2. DIN is safer demonstrably, incontrovertibly and in a manner that is both obviously and repeatably provable.

3. Dive operators using unsafer equipment? would be a interesting topic on a different post

 

[El Diablo]

Not true.....when it is time to replace a cylinder or valve, most get the convertible DIN/INT valve.

When "it is time to replace a cylinder or valve" might mean many, many years until this happens. That's why some folks here encounter issues when travelling abroad. Otherwise we wouldn't be having this conversation. Scuba tanks have a long life as you already know.

A little W-40 and heat are used to remove stubborn / stuck inserts

"Bad idea, and unnecessary".

Not the best idea obviously but the OP mentioned inserts 'fused' to the valve. The other options are to strip the threads or cut the valve. In both scenarios, the tank valve is destroyed. Feel free to massage the valve and talk nice to her until she decides to let go...

you are supposed to clean thoroughly the valve prior to usage

"Really? Why would this be necessary unless you have contaminated it with WD-40?"

No, it wouldn't be necessary if we didn't HAD to use extreme means to remove a stuck insert without destroying the valve. Tank valves can be EASILY cleaned, it is not the end of the road. Cut valves on the other hand, have to be replaced. Sharp thinking there...

15 years ago, DIN was practically unknown in the US.

"You are inventing facts".

You serious? The 15 years is not a specific date, I am trying to make a point. I obviously don't know when exactly modern DIN started to be commonly accepted in the USA! Do you???
Even now, stating that DIN is safer than YOKE is a criminal offense. Sharp thinking once again...

That mentality of yours is mesmerizing, especially when taking into consideration that you have to teach students...

You chose to ignore the fact that in the US, Asia & Pacific, the majority of Dive Operators (according to people in this forum living in those areas) offer predominantly INT valves.

You chose to ignore that 'fused' inserts cannot be stripped easily without ruining the valve. WD-40 is the last resort, when obviously one tried to force the insert loose with any other means. It is either that or cut the valve. You never seen any Dive Center do this???

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

 

[iain/hsm]

If the oring is the right size the yoke forms a metal to metal joint and it is impossible for the ring to extrude. Also if the oring is to thick it will stop the reg sitting in the grove and could be dislodged. User error can be a problem with yoke regs compared to din. But of course any reg can be damaged. I have poseidon din tanks and regs but find for everyday use the yoke is just to handy.

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.