BP/w Grab Handle?

[dmaziuk]

My wing is like that. To be honest, I didn't understand the OP's problem.

Most jackets I've seen have either that little strap, or the handle in the top of their "backplate", or both. A typical bp&w does not have anything of the sort. On Eric's plate it's easy to hold both straps in one hand but on regular ones you often need two to put it on the tank straight.

I thread a loop of paracord through mine for hanging it in DFB-SD gear room on Bonaire: it has wetsuit hanger rack in the middle and pegs along the walls for everything else.

 

[Storker]

Most jackets I've seen have either that little strap, or the handle in the top of their "backplate", or both. A typical bp&w does not have anything of the sort.

IOW, Halcyon isn't "typical". I have two Halcyon wings in my shed, both have that strap.

 

[dmaziuk]

The only thing my Hollis has is the corrugated hose.

 

[VE7DAC]

The threads take an axial (to the valve) load. Lifting the tank by the valve is a radial (to the valve) load.

I said lifting by the valve, you're mistakenly conflating that with lifting by the handwheel. I lift with three fingers under the handwheel, and one under the burst disk lip. This supports both sides of the valve, so there's no torque applied.

That being said, lifting by the handwheel is not going to damage a valve. If it did, every valve manufacturer would advise against it and training agencies would teach not to do it. And that's not the case. The 50lbs of a scuba tank, even applied at the worst possible angle, is not going to apply more force on the neck threads than a 3440psi fill. That's geometrically improbable, if not impossible.

Have you ever heard of a valve failing because it was lifted by the handwheel? Or are you just tossing around hypotheticals?

 

[Storker]

I said lifting by the valve, you're mistakenly conflating that with lifting by the handwheel.

I don't think I'm conflating the issues.

But it's very easy to misunderstand your post.

The 50lbs of a scuba tank, even applied at the worst possible angle, is not going to apply more force on the neck threads than a 3440psi fill. That's geometrically improbable, if not impossible.

You're again conflating axial and radial forces. They. Are. Not. The. Same.

 

[Sam Miller III]

@VE7DAC,

"Have you ever heard of a valve failing because it was lifted by the handwheel? Or are you just tossing around hypotheticals?
[/QUOTE]"

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Good gosh a 50 dive wonder Expert !
Yes! A long time ago when you were a little biddy boy and couldn't spell SCUBA.

As reported and documented by Tommy Thompson as a diving accident for the LA Co UIA news and Accident Report

At Catalina Island ( a story for @Dr bill)

A diver picked up a set of doubles by the center section to hand up to a diver on a dock . The valve ruptured, blowing the unit upwards breaking his wrist and fracturing a rib or two.

If an accident can happen It will happen

SDM

ps google Lt Comdr Leslie Tommy Tompson - USN -first person to lock out-dive under ice in 1948
PR for US Divers

 

[VE7DAC]

A diver picked up a set of doubles by the center section to hand up to a diver on a dock . The valve ruptured, blowing the unit upwards breaking his wrist and fracturing a rib or two.

If an accident can happen It will happen

SDM

ps google Lt Comdr Leslie Tommy Tompson - USN -first person to lock out-dive under ice in 1948
PR for US Divers

That sounds like a manifold failure, quite different from what we're talking about. These days nobody picks up a set of doubles from the center of the manifold, it isn't strong enough to do that safely, and beginning tech students are taught this.

I'm talking about picking up a single cylinder by the valve. The amount of torque that can be developed, even if lifting by the handwheel, is tiny by comparison. It's also common practice.

 

[VE7DAC]

I don't think I'm conflating the issues.

But it's very easy to misunderstand your post.


You're again conflating axial and radial forces. They. Are. Not. The. Same.

I understand that they are different, and also understand that threads, such as those on a scuba cylinder, are capable of withstanding both to varying degrees.

You claim that a cylinder valve could be damaged by being lifted by the handwheel. I believe that this is unlikely, as evidenced by the fact that nobody warns against it, including the manufacturers.

I am willing to listen to evidence that I am wrong, as I certainly have been before. Do you have any?

 

[Diving Dubai]

You're again conflating axial and radial forces. They. Are. Not. The. Same.

Actually metallurgical speaking its, compression, tensile and shear...

A valve under pressure is subjected to both compression and tensile forces in different parts

When you lift a tank by the valve, the shear is mitigated by the valve shoulder imparting teh load back to the cylinder

If you were (silly enough) to clamp a full cylinder horizontally by the valve, then the failure would be a tensile overload

Okay?

As you were...

 

[jpedersen]

My wing is like that. To be honest, I didn't understand the OP's problem.

As stated later by another poster, most bcd systems have a handle integrated of which may be commonly used to grab and lift the entire rig. My interest is that in having a better hold point than the valve. As previously mentioned, the valve is probably fine whereas the valve handle not so much.

I’m just thinking back to those plastic molded backpacks. Those were great for grabbing onto vs. a small and smooth tank valve.

I appreciate the discussion and ideas. Thanks. Jeff