Pressed Steel and regulator connections

[m3830431]

This has been brought up before. The issuse is the regulator and not the tank valve. Many Yoke connections, even on new regulators (Scupapro for one) are not rated to handle 3442psi. To be on the safe side you should sitch you reg over to din.

Paul

This is a repy from Apeks on the subject.

Hi Michael,

The Yoke clamp is rated to 232 bar if you contact our distributor they will be able to help you with your query if you need further details.

Aqua Lung America Inc.
2340 Cousteau Court
Vista CA 92083
USA

Tel: 760 597 5000
Fax: 760 597 4900
Website: www.aqualung.com

232 bar = 3364 psi

 

[D_O_H]

What if you move to Viton Orings for the (j)Yoke connection? Think the wear issues will be the same as the Trident black flake master Orings?

I use DIN, and have been using Viton Orings forever. I've never needed to change one out due to flaking and stuff. Usually I just lose them...

On the other hand, the blackies in the (j)Yoke valves on the rentals are often just shredded chunks.

Just curious.

Thanks

---
Ken

I have viton rings in my yoke PSTs. It's only been about 50 dives/9months, but I haven't had any problems so far at full pressure.

 

[oxyhacker]

Yoke ratings are funny. The yoke interface was originally intended to handle only 1800 psi or so. As pressures went up, they kept making the yokes heavier and stronger, but the dynamics of the actual seal - how the seat on the reg, the seat on the valve and the O-ring actually work together, stayed the same.

It's not that running too much pressure will cause everything to explode, it's just that, as the pressure gets higher, the O-rings become more likely to let go. At a certain point, it makes more sense to go to a DIN connector, but there's no clear line where that point is, though most people would agree it is somewhere between 3300 and 3800, and quite a few might put it lower.

So some companies, like SP and AL, rate their yokes, beefy as they might be, on what they feel is a safe, conservative rating for the actual seal, which is 230 (or 200, or 232 depending on what catalog you read) bar. Others seem to rate it based on the failure point of the yoke itself. The XS SeaAir yoke in a recent RSD test, for example, is rated at 4000 psi! This seemed to impress the testers at RSD, but is I doubt the XS yoke is any stronger than SPs or ALs, or the seal any more reliable.

So while I would not recommend buying a yoke reg to use on a high pressure tank, even if it has a dual mode valve, it certainly won't hurt to use a yoke reg on it occasionally.

 

[Lead_carrier]

What if you move to Viton Orings for the (j)Yoke connection? Think the wear issues will be the same as the Trident black flake master Orings?

I use DIN, and have been using Viton Orings forever. I've never needed to change one out due to flaking and stuff. Usually I just lose them...

On the other hand, the blackies in the (j)Yoke valves on the rentals are often just shredded chunks.



---
Ken

You used a key word there Ken.. Rental.. I use a (j)Yoke and have yet had to replace an o-ring on my gear because of flaking. Like you said, I usually loose it. Maybe it has something to do with the fact that the rentals aren't handled as nicely..

 

[miesemer]

I'm not fond of the combo valve supplied on the new 3442psi PST cylinders as a yoke connection. The oring supplied in the valves yoke adapter IMHO is too small. When filling with a yoke whip or attaching a yoke regulator they typically take some fiddling to get a leak free connection. All the fiddling/twisting takes it toll on the orings which in a very short time fail. My wife recently had one blow as she was entering the water. Needless to say, we're now only using DIN connections in the new PST valves.

I have had much better luck with Thermo's combination ProValve.

 

[Hoosier]

So some companies, like SP and AL, rate their yokes, beefy as they might be, on what they feel is a safe, conservative rating for the actual seal, which is 230 (or 200, or 232 depending on what catalog you read) bar. Others seem to rate it based on the failure point of the yoke itself. The XS SeaAir yoke in a recent RSD test, for example, is rated at 4000 psi! This seemed to impress the testers at RSD, but is I doubt the XS yoke is any stronger than SPs or ALs, or the seal any more reliable.

So while I would not recommend buying a yoke reg to use on a high pressure tank, even if it has a dual mode valve, it certainly won't hurt to use a yoke reg on it occasionally.

I agree. I have used SP reg and Apeks reg on 4000 psi, but I didn't have any problems so far. Acutally, o-ring on my 300 bar DIN has been blown out once. LOL~~~ I post it somewhere in this board...

 

[spectrum]

Quick question about the Pressed Steel E series: with their Yoke/DIN Valve are you able to use the yoke connection (as opposed to the DIN connection) at full pressure (3442 psi) or only when the tank is filled to 3000 psi or less?

You are limited by your yoke's rating. That my be 3000, 3442 or if older less than 3000.

Pete

 

[captndale]

I have seen many o-rings forcefully extruded from yoke connections at around 3400 psi while being filled. Based on that, I do not feel comfortable using yoke connections above 300 psi.

As for viton, I believe viton should probably not be used for regulator-to-tank-valve connections. Viton is more resistant to oxidation than the black stuff. However, viton is not at all resistant to abrasion. Oxidation is not really an issue, since the time of exposure is only a coulpe of hours at at time, at most. From my experience, viton o-rings wear out in a very short time (weeks or months), while nitrile can last for years.

 

[mack50md]

No problem with yoke valve at 3400 psi with PST E7-100 HPs w/ Thermo valves. Had O-ring issues from fill whips damaging rings. O-rings were Viton. No failures from the my reg seat. I had one instance on a trip where a fill station refused to pump 3400 into my yoke and gave me 3000. BTW same fill station blew my ring with their hot fills twice. I swear they had a burr on that whip. My local shops give me full fills with no problems or blown rings.

 

[mark99]

This has been brought up before. The issuse is the regulator and not the tank valve. Many Yoke connections, even on new regulators (Scupapro for one) are not rated to handle 3442psi. To be on the safe side you should sitch you reg over to din.

Paul

Actually the Scubapro MK25/S600 reg is rated to handle 230 bar. We've had complete discussion of this topic in a couple of other threads, particularly the reference to the leak in the Thermo Valve and yoke insert:
http://www.scubaboard.com/showthread.php?t=106950

As well as the issue of how you can possibly use a regulator with a yoke adaptor on a "High Pressure" tank:
http://www.scubaboard.com/showthread.php?t=101354

The summary is : The PST tanks with the Thermo 5 thread DIN valves with the yoke inserts are rated to 3442 psi. This is a particular configuration approved under standard ISO 12209. You have to be sure your yoke regulator is also approved for the higher pressure by contacting the manufacturer. Regarding the O-ring issue, the yoke insert in the Thermo valve comes in three configurations, the original, and two modifications. The two later designs, which were implemented to satisfy some European standard, actually seem to have problems in "retaining" the outer O-ring in the "channel". The ring often leaks when the reg is first connected, and pops out when the reg is removed. I started by just carrying a supply of extra rings, but this became such a hassle that I finally contacted the tank supplier, who was good enough to send me one of the original inserts. I haven't had any problems since. BTW the inserts are supplied with Viton O-rings because the tanks are "nitrox ready".