tank valve compatibility around the world

[Belzelbub]

Just why is yoke so popular when it's such an inferior and flawed design compared with DIN?

That’s the question, but I don’t think there is a good answer.

Just because a system has been developed to obsolete an older design doesn’t necessarily mean that the old design is actually obsolete. And based on what I see in local dive shops yoke is not going away anytime soon. I bought a couple regulators over the past few years for my daughters. In both cases, what was in the shop were yoke versions. That’s what sells right now.

I had hoped that the introduction of the convertible valve would have accelerated the obsolescence of the yoke regulator, but that doesn’t seem to be happening anytime soon. Lots of yoke-only tanks out there and they seem to be hanging on.

I’d guess that the majority of recreational divers in this area aren’t even aware of DIN. I know that the divers I usually dive with (apart from my kids) had never seen a DIN reg until they noticed me assembling my gear.

 

[2airishuman]

[...] After several trips to the Caribbean and FL Keys I got tired of finding the dive ops' rental tanks had either had yoke-only valves or, if convertible, that internal corrosion had frozen the plug in place. The dive ops with those convertible valves generally offered help when they saw me struggling to remove the plugs, but I got the feeling it was an annoyance to them. Often, they had to check a couple of different tanks for me until they found one they could remove the plug from.

This is exactly the situation I have encountered. I would add that the situation is potentially worse if you ask for a "special" tank e.g. nitrox or a size other than 80 cf.

P.S. I never liked the DIN-to-yoke adapter, as the space it took up made the reg sit too close to the back of my head. It has been pointed out in similar discussions that they only add maybe a half inch, but whatever the number, it's enough to make a difference to me.

Depending on the specific regulator and BC you're using, and your body shape, you may bump your head -- or not. Not an ideal situation.

Just why is yoke so popular when it's such an inferior and flawed design compared with DIN?

There are many threads exploring the benefits of each. The main reason yoke valves remain common is that they were in widespread use in this area long before DIN valves and regulators were readily available, and so they are preferred for reasons of compatibility.

They remain the preferred valve for resort/boat operators in Florida and the Caribbean because:

• DIN valves are easily damaged and rendered useless from impact while no regulator or port plug is in place.
• With yoke valves, it is faster to attach or remove a fill whip or regulator, a significant factor for operators filling dozens or hundreds of tanks daily.
  
• Yoke valves are somewhat cheaper in quantity, because they require fewer machining steps to make.
• They do not have the problem of the o-ring stretching and remaining in the valve if the regulator is disconnected while slightly pressurized.
• While any DIN reg can be used on any yoke valve with a converter (head banging problem aside), there are situations where yoke regulators can't be used on a DIN valve, even if the valve is convertible.
• Convertible valves pose particular problems for dive operators because the inserts tend to corrode in place.

The main problem yoke valves have that DIN solves is that it is possible to have the O-ring extrude during a dive if the clamp isn't tightened all the way, leading to a rapid loss of gas. Bottles carried valve-off as is common with stages heighten the risk because the clamp may be inadvertently loosened during the dive. That's a major risk on technical dives, but not on shallow reef dives where divemasters are present and OOA situations occur often for many other reasons.

I use DIN valves and regs at home. I bring yoke regs while traveling.

 

[tbone1004]

Just why is yoke so popular when it's such an inferior and flawed design compared with DIN?

basically what @2airishuman said. The yoke valves are way better for the dive operator...

 

[Lorenzoid]

Because this is 'merica and if there is a better way to do things, we'll dig in with our way and force the rest of the world to follow suit.

LOL. Or, to put it another way, because for a long time as "travel diving" was growing in popularity the majority of traveling divers were American.

Add to that what @2airishuman said about dive ops preferring yoke in their rental tank fleet because they're more convenient and resistant to abuse and I can see why dive ops would resist change.

 

[alex_can_dive]

I'm a bit slow today - but I still don't understand why yoke tank valves are any more resistant to abuses? (In fact, I would imagine it's more maintenance because it's got the o-ring in it, which presumably needs replacing every once in a while)

 

[Lorenzoid]

I'm a bit slow today - but I still don't understand why yoke tank valves are any more resistant to abuses? (In fact, I would imagine it's more maintenance because it's got the o-ring in it, which presumably needs replacing every once in a while)

See some of the bullet points in post #12. Regarding abuse, it's possible to cross-thread the reg if one doesn't take care in screwing it into the DIN valve face. If there is an imperfection from someone having cross-threaded or nearly cross-threaded it before, then the next person might apply even more force as they attempt to force the reg in past the imperfection. Also, the DIN valve face can get out of round if the tank is knocked over and the valve face hits the ground. I wouldn't have thought this likely, either. I mean, it's pretty thick metal, right? But I have found out-of-round DIN valve faces on several tanks at one dive op I used to rent from.

It takes just a few seconds to replace a yoke o-ring, but you're right, it is exposed to abuse. That's why I carry a lot of my own spare o-rings when I am visiting a place like Bonaire where the rental tanks see a ton of use.

 

[tmassey]

I'm a bit slow today - but I still don't understand why yoke tank valves are any more resistant to abuses? (In fact, I would imagine it's more maintenance because it's got the o-ring in it, which presumably needs replacing every once in a while)

A yoke valve is mostly solid brass, with some grooves machined into it and a small hole that leads into the tank. A DIN valve, on the other hand, ends up as a thin cylinder of brass with an internally threaded hole that you thread the regulator into. There really isn’t a lot of brass in that cylinder/dome on the top, and if it gets banged, it will go out of round, and you won’t be able to screw a regulator into it anymore.

 

[2airishuman]

I'm a bit slow today - but I still don't understand why yoke tank valves are any more resistant to abuses?

Well, to be very specific, the problem is that when the tanks are transported on their sides in a cart, trailer, pickup truck, or boat, they will eventually slide and hit a wall, bulkhead, gunwale, or whatever valve-first. The mass of the cylinder leads to an impact with quite a lot of momentum which is then absorbed by the top of the valve. Yoke valves are generally unaffected by any but the hardest hits because the vertical section is a large piece of brass throughout. DIN valves on the other hand easily have the threaded outlet knocked out of round since the top portion of it is relatively thin metal, and not well supported. Once this happens, the valve is scrap.

In theory tanks are supposed to be transported in a vertical position and secured with a bracket and straps or whatever, and in some places they are.

As for the o-ring, well, the dive ops buy them by the gross and there are extras on the boat.

 

[DogDiver]

I’m surprised no one mentioned the difference between 200 bar din valves and 300 bar din valves. You can attach a 300 bar regulator to either a 200 or 300 bar valve. But a 200 bar regulator will only fit on a 200 bar valve. They are machined differently. And they have a higher working pressure. That’s why you will see cave divers that typically over pressurize their steel cylinders to 3,800-4,000 psi using 300 bar valves.
Sorry I realized this the basic forum and this information is just for new diver education.

 

[broncobowsher]

I have seen a DIN tank take a fall and oblong the threads. Empty tank and install new valve. Yoke will take stupid abuse.

Couple years back I got on a big dive charter and was looking for a DIN tank. Everything was yoke. Except one little 63 that was convertible. Since it was just a bail out it was still more than enough for me. After 4 days I gave it back just as full as I got it. So all yoke style valves does still exist, even here in the states.

Yoke has been around forever. The first regulators were that way. The DIN stuff was an oddity for many years. But in the past 10 or so years has really started to go main stream. What is the ratio now? Hard to say. Anything with a strong tech diving area to it will have a lot more DIN. The more old and touristy will be a lot more yoke. The convertible tank valves are getting a LOT more common. Inserts are another issue. If removed, often lost. If not removed, often crustied in to the point they can't be removed.

The best answer I have, run a DIN regulator and keep a yoke adaptor in the regulator bag. You can run DIN when available, and when pressed into old school, attach the adaptor.

I have heard of dive shops getting a regulator in and the owner wanted it converted from yoke to DIN. So they unscrewed the adaptor that had been on the regulator since day one. People have DIN regulators and didn't even know it.