Question Yoke Regulator with Wreck Diving

[TylerG.]

A tank valve hand wheel is not a yoke or yoke screw. If you've rebuilt a valve or manifold before you would see just how tiny the stem is (which is what shears when you break off a hand wheel). I ask again... has anyone ever actually seen this "dislocating or completely shearing" a yoke against the ceiling of a wreck? For that matter, I question the yokes bending "all the time" short of massive abuse (like falling off the back of a truck while mounted on a tank, see @lexvil and @halocline comments above.) Like I said above, I get the snag hazards argument for certain conditions, but the dislocating or bending at a mere bump against the ceiling sounds like a whole lot of hand-wringing "what if".
So, question stands..... anyone ever actually see this terrifying failure mode in action?

Respectfully,

James

edit to add: I dive regs going back to the 50's, with very thin yokes (made of the dreaded weak brass) and am not particularly gentle with them.... have yet to bend one.

I didn't say "a tank valve hand wheel is a yoke or yoke screw", but that damage could occur under similar circumstances. Yes the hand-wheel stem is fragile compared to the bulk of a first stage, but remember a yoke is only held on by the clamp and whatever pressure may be exerted when it is pressurized. If a yoke is hit then it will leak/come off, as for how much force is required is up for debate, i'd think around 100-200lbs would cause a moderate leak? What do you think?

 

[TylerG.]

^^ This is in the original question though. The question is not: I am going to be an expert technical wreck diver, should I get a yoke or DIN regulator?

I think the issue is that the OP said "in" wrecks. How far inside is he talking about? @DrMattWill

 

[James79]

I didn't say "a tank valve hand wheel is a yoke or yoke screw", but that damage could occur under similar circumstances. Yes the hand-wheel stem is fragile compared to the bulk of a first stage, but remember a yoke is only held on by the clamp and whatever pressure may be exerted when it is pressurized. If a yoke is hit then it will leak/come off, as for how much force is required is up for debate, i'd think around 100-200lbs would cause a moderate leak? What do you think?

Correct, you didn't say a yoke is a handwheel, but you described the theoretical "hitting the yoke on the ceiling, dislocating or completely shearing it off." Then followed with "This problem isn't actually that uncommon, I've seen back-mount divers shear off the hand-wheels on manifolds before. And yoke, especially brass ones, bend all the time."
You used the handwheel incidents you've seen to say yokes can fail the same way, and said the problem isn't uncommon. The yoke clamp on all modern regs is far beefier than a valve stem. I have (to my shame admitting it) run a yoke reg with the early, very thin, USD yoke into the top of swim-through at a moderate speed.... with no ill effects.
I would agree with your final point, that sufficient impact will dislodge a yoke. But from what I've seen, sufficient impact isn't achieved by the speeds a diver swims at..... as evidenced by not a single example being brought up in answer to my question of "who has seen it happen in the water?". I haven't tested for it (even if I wanted to build a test rig, I don't want to trash a reg for the sake of it), but I have seen hard enough hits to a yoke due to poor buoyancy/lack of attention to feel that particular risk isn't a determiner. Could it happen? Theoretically. So could a simultaneous total failure of both you and your buddies 1st stages. I think they are in the same ballpark of likelihood.
As I mentioned upthread, snag hazard is an argument for DIN that holds water (if you'll pardon the pun)... people have had entanglements on the yoke screw that a DIN reg could not have had (numerous first hand accounts) that make DIN a preferable choice for high entanglement risk scenarios. The possibility of bending a yoke mid dive as your reason to not buy yoke just sounds like too much what if with no example of ever happening.

Respectfully,

James

 

[boulderjohn]

I own a lot of tanks and a lot of regulators, and every one is DIN. On the other hand, I can see very good reasons why someone would prefer yoke for the kind of diving they do. In much of the world, yoke is very much the norm, and showing up with a DIN regulator can create a problem. When my friends and I went to Palau, we filled out the forms ahead of time noting that we had DIN regulators, but the company saw we were American and just assumed we wanted yoke. ("Where's your national pride?" the DM asked when he saw the mismatch.) Luckily we had brought adapters that first day.

I have seen more than a few occasions when someone with a DIN regulator has to have the pro plug donut removed from the tank valve, only to find that the sucker won't budge because it has been in there for years.

As some have noted, DIN's are far from perfect. I do a lot of diving in a freshwater lake, and I have to remember to clean the threads of both my regulators and my tanks with vinegar to get rid of the tiny film of minerals that makes it hard to turn. I have gotten DIN valves out of round with only minor bumps, and I carry a big wrench so I can use a stainless steel DIN plug to retap the threads when that happens.

Yoke valves have many advantages for a dive shop working with lots of tanks. When filling tanks, multiply the extra time it takes to do a DIN tank by the number of tanks that need to be filled.

 

[gamon]

Are yoke valves snapping off of tanks inside a wreck such a problem?

I've never heard of such a thing.

I must be diving under a rock.

 

[Eric802]

Are yoke valves snapping off of tanks inside a wreck such a problem?

I've never heard of such a thing.

I must be diving under a rock.

Well I hope you're not doing it with a yolk regulator, that rock will sheer it right off.

 

[gamon]

Well I hope you're not doing it with a yolk regulator, that rock will sheer it right off.

Why would my yoke regulator sheer off if I dived under a rock?

Wouldn't I need to actually hit the rock for that to happen?

 

[Lorenzoid]

Are yoke valves snapping off of tanks inside a wreck such a problem?

I suspect that if one scoured reports going back decades, one could find an incident or two. Is it "such a problem" for swimming through wide open spaces on the commonly dived wrecks that the OP is going to visit? Would it be "such a problem" for venturing through doors and hatches into rooms inside a wreck? Possibly different answers.

 

[gamon]

I suspect that if one scoured reports going back decades, one could find an incident or two.

I've never heard of a single incident of a yoke regulator snapping off inside a wreck or under a rock and I highly doubt anyone reading or posting to this thread has either.

Go ahead somebody prove me wrong.

 

[BoltSnap]

For personal use with my own Tanks, I'd not consider using Yoke. I switched to DIN in the 80's with Sherwood valves/tanks and never went back. The only time I use Yoke is when traveling to locations that don't have DIN (recreational diving). I have a dedicated Yoke regulator (and spare) for travel but my regulators used in local diving or when I travel to locations in the US with my Tanks, I use DIN exclusively. In my last few dive trips the last 5 or so years, I traveled with my DIN and it was no issue at all. Dive operators use valves with DIN insert and remove this insert for me. Perhaps a couple of times they couldn't remove the insert, so they brought me another tank. I'd still communicate with the dive operation at the travel destination to make sure that they have DIN tanks available for me. If not sure or can't verify, I always carry a Yoke spare regulator with me and a a Yoke adapter.

I don't remember seeing Yoke regulators explode off the tank valve but I have seen MANY Yoke o'ring extrusions during the dive. These extrusions usually happen on the surface or very close to the surface when the Tank has the highest pressure before air is used underwater. The tank is drained in only few minutes. There is also tank o'ring leakage. Both scenarios never happen with DIN Valve/Regulator.