settle disagreement on din/yoke valve and max pressure

[Rick Inman]

Yes, yes, I know that Din valves are superior. That is NOT the question.

The question is, which of the following is true:

1) Hp 3500 steel tanks should never have a yoke valve (pressure too high for yoke).

2) It is fine to use a yoke with an HP 3500 steel tank.

 

[Mo2vation]

Yes, yes, I know that Din valves are superior. That is NOT the question.

The question is, which of the following is true:

1) Hp 3500 steel tanks should never have a yoke valve (pressure too high for yoke).

2) It is fine to use a yoke with an HP 3500 steel tank.

The new E series has convertable valves. Just this weekend I needed to put a (j)Yoke on mine - screw in the flambus, the whole thing. If 3500 is too much, is 3446 not?

---
Ken

 

[padiscubapro]

The new E series has convertable valves. Just this weekend I needed to put a (j)Yoke on mine - screw in the flambus, the whole thing. If 3500 is too much, is 3446 not?

---
Ken

first the dot will not authorize yokes for that high.. 3446 is the most thats why those tanks are rated that way.. The big issue is, can the yoke you are using handle the pressure.. alot of the older yokes are not made to support pressures that high (some of the really old yoke really weren;t meant for even 3000 psi!!!)... the newer yokes are beefier... Also the higher the pressure goes the greater your chance for o-ring extrusion..

 

[Mo2vation]

first the dot will not authorize yokes for that high.. 3446 is the most thats why those tanks are rated that way.. The big issue is, can the yoke you are using handle the pressure.. alot of the older yokes are not made to support pressures that high (some of the really old yoke really weren;t meant for even 3000 psi!!!)... the newer yokes are beefier... Also the higher the pressure goes the greater your chance for o-ring extrusion..

But lets pretend, for a moment, we're not talking some 1970's or 1980's vintage reg. We're talking a reg purchased in this decade. Do real manufacturers (the SP's, USD's, etc. of the world) make Yoke rigs that can't take 3500? I mean really... could they possibly? In SoCal I see a lot of steel tanks.

Its just a surprising thought - that someone over the last 10 years or so wouldn't make a yoke reg that could go to 3500. In the last 6+ I've been certified, I've been diving HP steels almost exclusively.

Maybe I'm just diving in my own, narrow world. That's very possible.

---
Ken

 

[jamiep3]

One of my Conshelf XIVs has a yoke rated at 4000psi. My Mares reg, bought new in 2003 is rated 240 bar.

 

[pgdive]

Recently I had a customer call ScubaPro about his 1 year old reg and he was told that the yoke could not handle the 3442psi on his new PST. Yet most of the people that I see diving the PST tanks use them with a yoke connection, becasue this is what they already have and are familar with them. It's all very dodgy.

On a side note Leadking (Sea Pearls) from this board took 20 minutes to explain the pressure/yoke/din issue to me from an industry standpoint. Definetly a class act and a great company, since I wasan't even asking about a tank that he sold.

Paul

 

[The Chairman]

It's sort of amazing and sort of funny how arbitrary the whole mess is. The e-series tanks are a great concept, and I am glad that they finally did it.

While I would NEVER suggest that you exceed manufacturer recomendations, I feel that many of these are mostly "CYA" on their part. I have used yokes on those tanks, and will do so again, I am sure.

 

[gjmmotors]

Rick- Did you mean the old 3500 psi bottles or the new PST jobs?

All of the older HP tanks that I have seen or dove had a DIN fitting. Before the the new PST'S came out (which share the LP valve thread size) were there even yoke valves made that would fit the HP tanks? I never saw one.
-g mount

 

[Charlie99]

Yes, yes, I know that Din valves are superior. That is NOT the question.

The question is, which of the following is true:

1) Hp 3500 steel tanks should never have a yoke valve (pressure too high for yoke).

2) It is fine to use a yoke with an HP 3500 steel tank.

It's fine to use SOME yokes or A-clamps at 3500. Look at the manual for the reg in question. For example, the Zeagle regs are rated to 240bar / 3500psi with a yoke connection.

http://www.zeagle.com/clientuploads/Manuals/Reg_Manual_99.pdf

 

[Padipro]

Rick- Did you mean the old 3500 psi bottles or the new PST jobs?

All of the older HP tanks that I have seen or dove had a DIN fitting. Before the the new PST'S came out (which share the LP valve thread size) were there even yoke valves made that would fit the HP tanks? I never saw one.
-g mount

The older HP tanks were 3500 psi and came with 300 bar valve and there were no yoke regs, or valves, made that would fit a HP tank. The LP tanks came with a 232 bar DIN valve that had an incert that could be screwed in to accept a yoke reg just like the E series tanks do now. This incert could be screwed into a 300 bar valve but still would not work with a yoke reg, even if it would fit, as it would screw in to far to seal the o-ring to the reg first stage.

Yoke regs I've owned over the years were stamped with 3000 PSI right on the yoke which leads me to believe that they were not designed to handle the increased pressure of HP tanks. Now many of us pump our LP tanks to 3000 psi even though they're stamped with a working pressure of 2640 psi at 10% overfill and they work just fine with high pressure burst disks installed. I'm sure the reg would probably work just as well at the higher pressure but would you really want a first stage with a 3000 psi yoke attached to a 3500 psi tank right behind you're head?

If you're interested in going with a DIN valve go with the high pressure, 300 bar, valve and be done with it.