ball swivel question

[Mo2vation]

Hi all,
Went diving for the first time in a couple years last Saturday, and during the dive I was reminded how my second stage hose caused me to have to bite down harder when turning my head. Not really a big deal, but at the same time, kinda annoying.
I'd read a couple other posts about the ball swivel: http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=BallSwivel
and I was wondering, do all you folks that get to dive all the time use them?
Do they decrease jaw fatigue?
What kind of seal do they have in them?
And are they universal fit, or do I have to identify fitting type, thread pitch and all that stuff?
And the last question, Has anybody ever had one come apart and totally fail during a dive?

My wife had hers blow up at 58 feet in Belize a couple of weeks ago. The ensuing jacuzzi and noise made our first real OOA situation a little dicy, but everything came out all right.

Never, ever in a million years would I put one of these after-market death traps on a regulator.

Don't confuse the Trident (and that ilk) with the Atomic. The Trident is 100% reliant on a screw to keep the two round pieces together. Screw gets loose, Oring is pressure forced out and instant explosion. I do not want my gas delivery system reliant on a part that is this feeble.

The Atomic has no such screw, it not cheaply built, won't have the chrome flaking off in a couple of months / weeks and is in a different league. That said, I don't have the Atomic swivel on my Atomic rig, nor will I.

The DM on our Belize boat had this happen to him personally about 5 years ago, and two others on the boat said they were in groups where this has happened (sudden swivel explosion syndrom SSES.) I believe it.

No thanks, man.

---
Ken


PS: I'm one of those guys. It is and was another failure point. Her reg was serviced 7 months before the incident. No I didn't take a screwdriver from the drybox and examine the thing before every dive. But I pulled a wrench from the box and tossed the damn thing overboard immediately after the incident.

 

[The Kraken]

In my opinion the term "death trap" seems a little harsh. No one died from the incident. Normal emergency procedures, and so forth . . .

Probably happens a lot less than a freeflowing regulator at depth, which is equivalently the same thing.

. . . to each his own.

the K

 

[Mo2vation]

Probably happens a lot less than a freeflowing regulator at depth, which is equivalently the same thing.

the K

A properly adjusted reg won't flow like this - 35 minutes into the dive. 6 years with them - not once. Never an issue.

Our regs (maybe not all) have an adjustment that I can use to control or eliminate this occurance.

The reg was functioning perfectly. This was an aftermarket product bolted into the gas flow. The product has a serious design issue and I can't recommend against it highly enough.

---
Ken

 

[Tom Winters]

I guess there are swivels, and then there are swivels. Mine are made by M&J Engineering. I've had them apart - there are two o-rings in there. I don't open them often, but I do check that elbow screw for tightness pretty much every time I rig up.

http://www.mj-engineering.com/shop/

 

[fishoutawater]

So Kraken is for the swivel, and Ken adamantly opposes it.
There is a lot to be said for simplicity of design as far as safety/reliability.
And I could see where it might become a problem if I got to dive as much as people on a coast. I'd probably get complacent with my equipment inspections and forget to check screw in ball swivel. Having said that, I am extremely anal about equipment inspections. I do it for a living on fighter jets. Fighter pilots get kinda PO'd when something breaks and I failed to discover/fix/prevent the occurance. Such occurances are far and few in between, certainly nothing life or mission threatening. OTOH, DIR principles just don't work on fighter jets. Lots and lots of moving parts. Nothing simple about them. Constant inspection and maintenance is the norm on fighters.
Has anybody considered putting a tiny amount of red Loctite on the screw holding the swivel halves together? (red Loctite is stronger than the blue) Of course, I have no idea if there are any health ramifications to breathing any residual Loctite fumes at depth. I do know that Loctite is NOT approved for use on pure oxygen systems, so I definately wouldn't use it for NITROX.
I agree that they could've designed the thing better. Might be uglier, but I wouldv'e designed it so it could be safety wired, or cotter pinned.

 

[fishoutawater]

Thanks for that link Tom. Looks like a pretty robust design. Happen to know if yours has any kind of positive locking feature on the screw?

 

[The Kraken]

A little bit of "Lok-Tite" goes a long way.

Applied to the outter threads of the screw it would have very, very little, if any, contact with the breathing gas.

the K

 

[the_cat_keeper]

My Apollo reg comes with a swivel joint. Friends and I have it for a while already. Never had a failure.

 

[Tom Winters]

No locking feature on the screw other than me honking down on it. I did notice that the manufacturer has a rebuild kit for $12. I'm a little leery of Locktite though, especially under pressure.
Maybe if they had a real gnarly denture adhesive for the hard-core geezers - that I'd use on the threads because they're always throwing geeze into hyperbaric tanks.
Next time I visit friends with some little kids, I'll leave some different colors of Locktite out and see what a couple of squirts does to them.

 

[The Kraken]

For a screw to extract itself from the mating part while under pressure is difficult.
The pressure exerted serves to make the parts come in closer contact thereby increasing the friction between the mating surfaces. Kind of like trying to take a radiator cap off when the engine's overheated. The pressure increases the resistance of the cap being turned.

the K