Pressed Steel and regulator connections

[Leadking]

I had a customer who runs a large operation call me about o-rings extruding out of Thermo's Pro valve. We did a confernece call with Thermo and went over all the issues. Themo was willing to fly a rep in to see the problem first hand as they were not able to duplicate it. One of the subjects discussed was damaged fill whips. Our customer reviewed his fill whips and found that they were damaged and had various debris accumulated on them. He put on new whips and "has not had a failure" since.

 

[Leadking]

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.


The important thing is know is what is your regulator's yoke rated for.

The reason for PST/Worthington's use of a Thermo Pro valves use on a 3442 psi cylinder is because the European 230 bar @59C equals 3442 @70F and is a recognized standard.

 

[mark99]

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.


The important thing is know is what is your regulator's yoke rated for.

The reason for PST/Worthington's use of a Thermo Pro valves use on a 3442 psi cylinder is because the European 230 bar @59C equals 3442 @70F and is a recognized standard.

Yes but I haven't been able to determine the exact reason that they changed the design on the yoke insert. I have one of each. The outer O-ring on the original design is held in place by a little lip running around the edge of the channel. On the new design there is no lip, just the channel. There is no way the 112 O-ring will fit- my LDS supplied me with some smaller ones that could be stretched a little over the center and held with a little friction. Doesn't work very well.

 

[Hoosier]

These pictures show some wearness after using 4000 psi fill several months.
I think it is time to replace the O-ring though....

Here are more pictures:
http://www.scubaboard.com/gallery/showphoto.php/photo/30992/cat/500/ppuser/33800
http://www.scubaboard.com/gallery/showphoto.php/photo/30990/cat/500/ppuser/33800

 

[mark99]

I'm a little confused-your earlier post referred to a blown O-ring on a 300 Bar DIN- and you are referring above to 4000 psi fills with the adaptors shown in your pics. These adaptors are only rated to 232 bar, right? I'm also wondering what valve you are inserting them into?

 

[Hoosier]

Yes and no.

The inner O-ring of 300 bar DIN kit has been blown out once. It was the DIN kit problems, not a tank valve. I have another same regulator with the same DIN kit. That is OK. I think I had a bad patch.

It is the genuine 232 bar Yoke/DIN valve on my PST tank. Even though I fill it up to 4000 psi (cold fill), I don't have any problem even with Yoke valve (other regulator).

 

[mark99]

I saw the pictures that you linked to (DSCN 1824), that show the shredding around the outer edge of the outer ring. Most likely due to the abrasion during fills. I'm more concerned about why you are getting the extrusion of the inner ring (picture DSCN 1822)- maybe from the increased pressure (4000 VS 3442).

 

[Hoosier]

That's what I am thinking. Definately, the overfill comes short of the ordinary O-ring life. But, it is 2 cent per ring so that I don't care that much.

As for the inner O-ring, here is another thread that I post. Check it out.

I was told that many cave divers used to fill PST tank up to 4500 psi... Of course, it is with 300 bar valve though.

I saw the pictures that you linked to (DSCN 1824), that show the shredding around the outer edge of the outer ring. Most likely due to the abrasion during fills. I'm more concerned about why you are getting the extrusion of the inner ring (picture DSCN 1822)- maybe from the increased pressure (4000 VS 3442).

 

[SCUBA-J]

That's what I am thinking. Definately, the overfill comes short of the ordinary O-ring life. But, it is 2 cent per ring so that I don't care that much.

As for the inner O-ring, here is another thread that I post. Check it out.

I was told that many cave divers used to fill PST tank up to 4500 psi... Of course, it is with 300 bar valve though.

5-3 Valves on air comtainers
Connections CGA850 (limited Standard Cylinder valve yoke cconnection)-have been assingned for use with self-contained underwater breathing apparatus(SCUBA) based on historical use and the SCUBA regulator and ancillary equipment designs.Except for CGA 852 (DIN),which may be used with cylinders rated to 5500 psig at 70*f these connections may be used with cylinders rated to 3000 psig at 70*f filled in a manner that complies with the rating for the cylinder.

Connection CGA 850 is limited standard cylinder valve yoke connecton for pressures up tp 3000 psig for SCUBA air. Its is limted to use in SCUBA.

this is from the CGA G-7-2003 the set the standard on all gas magament items ,what it boils down to anything over 3000 psig should be DIN and anything under 3000 psig can be yoke, it has nothing to do with what is stamped on your yoke.

 

[mark99]

This is taken directly from page I-5 of the Scubapro MK25 regulator user instructions, "Scubapro first stage regulators are available with either of two different cylinder valve connections:
Threaded, this connector uses a knurled and threaded retaining wheel and complies with ISO 12209-2 (200 or 300 bar).
Yoke, this international connector consists of a yoke and knob type fixing screw for use in systems up to 230 bar and complies with ISO 12209-1."

And here is a summary of the standard:

• ISO 12209 (Gas cylinders - Outlet connections for gas cylinders valves for
compressed breathable air) was released in 2000, giving full dimensional details
and upper pressure limits for:
o In its Part 1, the yoke type connection almost universally used for SCUBA
applications, for use at up to 230 bar (23 MPa) cylinder filling pressure at
15°C
o In its Part 2, two threaded connections derived from the German DIN 477
Standard, one for use at up to 230 bar (23 MPa) cylinder filling pressure at
15°C and another for use at up to 300 bar (30 MPa) cylinder filling pressure
at 15°C
o In its Part 3, an Adaptor for 230 bar valves which allows a valve with the
threaded outlet of Part 2 to be connected to an application complying with
the yoke connection of Part 1.

I wish we could agree that there are regulator manufacturers that make yoke connectors that can be used at 230 bar, and valves with DIN connectors that can be used with a yoke adaptor (hoosier's pics above) at up to 230 bar.