O-ring Wear and Tear

[holdfast]

Okay so I recently had two o-rings “burst” on the same day. Specifically, the ones on the cylinder valve, where the first stage connects to the cylinder (yoke).

Essentially the o-ring seems to have become stretched and air began rushing out where the reg meets the valve.

I guess my question is — is this a weird occurrence? Both rings bursting on the same day? I guess it’s a sign that they were subjected to relatively equal wear and tear (because they were replaced on the same day as well).

My other question is — is there a way to tell, or a rule you like to follow about when to switch (rather than waiting for a major blowout)?

One thing I should confess is that I am guilty of over tightening the yoke a bit. I am trying to do that with a much lighter hand. I can easily imagine that habit increasing wear on the o-ring.


Anecdote:

I’m in the kitchen making a sandwich, and this startlingly loud racket kicks up in the other room. I run into my bathroom, where some gear is soaking in the tub. It’s a sh*tshow. Steam, water, and pressurized air blasting everywhere. I manage to stand the tank up and get the valve closed. Then I just kind of stand there, the entire front of my body soaked and water pooling on my bathroom floor. I let the adrenaline dissipate and begin to investigate what happened. After I finish my sandwich.

Whenever things like this happen, I always imagine what it would have been like to have been on a dive.

 

[Akimbo]

How long since the O-rings were changed? Not sure what you mean by "changed on the same day". Could be you are not tightening the regulator enough. An O-ring blow-out is NOT common at all.

Edit: Another possibility is the seat on your regulator is damaged.

 

[Redshift]

Were the cylinders yours or from some diving centre?
Those o-rings are quite exposed. There was a not-so-old thread here of someone complaining about cylinder o-rings in some dive centres being very poor and not sealing properly.
I think what they do is that they change them once they burst. Usually that happens when turning on the tank... But if you notice them leaking you should change them.

 

[Bob DBF]

How long since the O-rings were changed? Not sure what you mean by "changed on the same day". Could be you are not tightening the regulator enough. An O-ring blow-out is NOT common at all.

Edit: Another possibility is the seat on your regulator is damaged.

I thought my reg seat was damaged, actually it was, but that was not the issue, and don't ask how I fixed it. It seems that this Faber tank valve has a different o-ring than the good old US of A, I didn't know there was any other kind, standard o-ring. If you use a standard o-ring in the Faber convertible valve that came with the tank, a regulator will seat properly intermittently. I don't know what problems happen if there is a switch the other way, but although, to the eye, they look the same, they are not. Probably a metric thing.


Bob
--------------------------------
“I am always ready to learn although I do not always like being taught.”
― Winston Churchill

 

[Phil_C]

There is another possibility which is worth considering - on yoke connectors you can actually damage and deform the o ring if you 'over tighten' when fitting the yoke. it stretches the o ring and can cause it to start to extrude out of the fitting. Over time this will cause a failure as you describe.

You only need to tighten the yoke enough to seat the connector faces correctly, and then tighten hand firm, and then pressure will make the seal. If it is so tight that it is hard to get off after the dive then maybe you are over tightening when fitting which will lead to premature failure.

It's one of the reasons I went to DIN - on the rental tanks I was using abroad the O rings were frequently b******d from being tightened to within an inch of their life and failures were quite common. - Phil.

 

[holdfast]

How long since the O-rings were changed? Not sure what you mean by "changed on the same day". Could be you are not tightening the regulator enough. An O-ring blow-out is NOT common at all.

Edit: Another possibility is the seat on your regulator is damaged.

I brought them in to get them filled or something similar, and the guy popped some new ones on there. This was a few months ago maybe, I can't recall exactly. Those o-rings both failed within hours of each other a few months later. I haven't noticed any major damage on the reg. I'll take a closer look at that. I assume I am looking for big dents and scratches.

Were the cylinders yours or from some diving centre?
Those o-rings are quite exposed. There was a not-so-old thread here of someone complaining about cylinder o-rings in some dive centres being very poor and not sealing properly.
I think what they do is that they change them once they burst. Usually that happens when turning on the tank... But if you notice them leaking you should change them.

The cylinders are mine. Two relatively new aluminum 80s. I bought a handful of spares, so that if I get the slightest suspicion that they need changing, I'll be ready.

I thought my reg seat was damaged, actually it was, but that was not the issue, and don't ask how I fixed it. It seems that this Faber tank valve has a different o-ring than the good old US of A, I didn't know there was any other kind, standard o-ring. If you use a standard o-ring in the Faber convertible valve that came with the tank, a regulator will seat properly intermittently. I don't know what problems happen if there is a switch the other way, but although, to the eye, they look the same, they are not. Probably a metric thing.

You might be able to educate me a bit here. I'm not sure if the valves are Faber or not. Maybe they manufacture and others rebrand. I can say that one is chromed has a Sherwood logo, and on the back has "13/04" etched into the metal. The other has a more sandblasted finish and has a large "H" cast into the metal itself, and on the back has "12-07". I imaging the numbers are dates, but could be way wrong. I'm not expecting you to have some encyclopedic knowledge of this topic, but just throwing it out there.

I picked up some of these: Oxygen Compatible O-Rings, Lubricant and Tools - Dive Gear Express (size: 014) and the *seem* to fit well.

There is another possibility which is worth considering - on yoke connectors you can actually damage and deform the o ring if you 'over tighten' when fitting the yoke. it stretches the o ring and can cause it to start to extrude out of the fitting. Over time this will cause a failure as you describe.

You only need to tighten the yoke enough to seat the connector faces correctly, and then tighten hand firm, and then pressure will make the seal. If it is so tight that it is hard to get off after the dive then maybe you are over tightening when fitting which will lead to premature failure.

It's one of the reasons I went to DIN - on the rental tanks I was using abroad the O rings were frequently b******d from being tightened to within an inch of their life and failures were quite common. - Phil.

This actually something I must admit to being guilty of. I am paying much closer attention these days, and trying to avoid that, but the damage may have already been done. At some point I am going to treat myself to a higher-end regulator. I have a convertible valve, so at that time I may switch to DIN. My next big purchase is hopefully going to be a drysuit though


Anyway thank you guys for your thoughts. It sounds like my big takeaways are:

• Stop over-tightening the yoke
• Make good and sure I am using the correct o-ring size
• Check my regulator for defects, or have professional look at it

 

[Akimbo]

…
• Make good and sure I am using the correct o-ring size
• Check my regulator for defects, or have professional look at it

Unfortunately, the “professional” who put the O-rings in a few months ago “may” be the culprit.

 

[Bob DBF]

You might be able to educate me a bit here. I'm not sure if the valves are Faber or not. Maybe they manufacture and others rebrand. I can say that one is chromed has a Sherwood logo, and on the back has "13/04" etched into the metal. The other has a more sandblasted finish and has a large "H" cast into the metal itself, and on the back has "12-07". I imaging the numbers are dates, but could be way wrong. I'm not expecting you to have some encyclopedic knowledge of this topic, but just throwing it out there.

Don't worry about it, the valve would be on a steel Faber tank. But if you had one of those o-rings in your valve it might cause your problem. As I said before, looking at them both o-rings look the same.



Bob

 

[herman]

Another possiblity is the orings that you have are not the correct durometer (hardness). If they are too soft premature blowout is very possible. If you have more of them, you may want to get more from a different source and compair them.

 

[spectrum]

I have a convertible valve, so at that time I may switch to DIN.

Remove the inserts and reinstall them torquing them lightly. In my experience if you wind them in tight the insert will cock in the natural skew of the threads and leave the yoke o-ring in the wrong place. Seat the DIN o-ring and let that define how the insert rests.

Pete