new european valve standard ?

[SPEEDSTER]

I was in talking to a LDS about the new tank I want to get and he started talking about a new valve standard in Europe. Supposedly its like a reverse DIN, where the tank is the male connection and the regulator is a female connection. Has anyone heard of this?

mike

 

[thethumper]

Nope.... But sounds intersting. It may suck for those who just bought or converted to DIN though....:bonk:

 

[roakey]

There was a brief flirtation in the industry with a reverse DIN for Nitrox regs. If you pick up a SCUBAPRO catalog from about 2-3 years ago they were touting it as the future. Well, the future never got here and SCUBAPRO's interest only lasted 1 year and I haven't heard anything else about it.

It had everything going against it: It put the external threads on the cylinder, which means that they'd get banged up really easily. In typical industry fashion the solution to this was NOT to drop the idea there, but to heap a fix upon the problem they created: A shroud over the threads, which now traps water and can get bent up.

Thankfully the idea died, and I expect that your LDS just has some old, recycled information. Putting the threads on the cylinder is a horrible idea and I think the industry finally figured that out.

Roak

 

[DiverBuoy]

roakey once bubbled...
There was a brief flirtation in the industry with a reverse DIN for Nitrox regs. If you pick up a SCUBAPRO catalog from about 2-3 years ago they were touting it as the future. Well, the future never got here and SCUBAPRO's interest only lasted 1 year and I haven't heard anything else about it.

It had everything going against it: It put the external threads on the cylinder, which means that they'd get banged up really easily. In typical industry fashion the solution to this was NOT to drop the idea there, but to heap a fix upon the problem they created: A shroud over the threads, which now traps water and can get bent up.

Thankfully the idea died, and I expect that your LDS just has some old, recycled information. Putting the threads on the cylinder is a horrible idea and I think the industry finally figured that out.

Roak

I don't like the idea because it likely means the o-ring is back on the tank. To put it in perspective, I replace the o-ring on the yolk style tanks like once every 20 dives - I have never replaced the o-ring on my regulator - ever. And I check it every dive - no cuts knicks, or issues - just perfect, I can replace on my terms.

(hey my 400th post)

 

[SPEEDSTER]

Roakey, I had brought up those same issues with him, (not knowing it was an old idea) but he just shrugged it off and said that it was coming. It wouldn't surprise me if it is old news. I should have known better, they have alot of OMS gear.

mike

 

[GTADiver]

: It put the external threads on the cylinder, which means that they'd get banged up really easily

How is it different than a CGA 346 or CGA 347 on an SCBA bottle?

 

[pescador775]

Yes, the CGA 540 (oxygen) has external valve thread also. I don't think that this style is appropriate for SCUBA for the reasons given above.

I don't understand why anyone would have to replace their yoke valve O ring after 20 dives. My O rings normally last for 5 years. I use the white (silicone) O rings which are of a harder material than the black variety. They eventually turn yellow in the sun but do not deteriorate in any way that I can see.

The history and use of O rings is surprisingly complex. In the 'old days' O rings were not even used. Rather, there was a washer similar to medical oxygen valves. Yes, these were good only to 2150 psi and had to be replaced annually. Later, there was a fat O ring which was of the 'static' type. That is, the O ring was crushed by tightening the regulator. These were suitable up to 3000 psi with regular maintainance. In the 1970's, Sherwood and others made some incremental changes to the yoke valve and its O ring design. The O ring annulus (groove) was made smaller to accept a thin O ring. The annulus was machined with a small indent (to relieve air pressure under the ring). With this redesign the regulator no longer crushed the ring but compressed it until the regulator made metal to metal contact with valve face. To this day, I cannot see how an O ring of this type installed in a good valve could extrude or pinch. I have used these up to 4000 psi with no problems. However, even a small scratch or dent in the valve face could cause unreliability of the O ring. Also, the durometer (hardness) of O rings is design specific as we have seen with piston regulators. This means that hardware store rings may not be suitable for some SCUBA applications. If the right O ring is used on a good yoke valve it stands to reason that the pressure retaining capability should be very reliable.