Blown o-ring at depth :o

[Tigerman]

Im posting this in this section as ive seen it come up in other threads on the board.

August 2009 - Sharm El Sheikh, Egypt (~40c/105f air temp)
Were jumping in for some manta ray action for our third dive of the day. We actually spotted one from the boat so we jumped in and followed it for a few minutes, ending up at around 20m/65 ft.
When I look back at my buddy I think shes having a way big exhale, but it last too long and she turns around looking for the weird sound coming from behind her and I realize theres a REAL major leak from her tank valve. I get closer to her and offer my octo, but she dont realize whats going on as she cant see the bubbles and think its a speedboat or something she explains to me later.
I signaled for her to stop, look at her pressure gague and take my octo before I shut down her tank valve and we start to get closer to the reef and ascend as we where pretty far away from the reef out in the blue.
We never got noticeably stressed or anything, so from that point of view it was just a perfect air-share ascend drill.

My buddy was a small woman that usually use about half the air I currently do.
I came up with 30 bar/435 psi less than I jumped in with while she had used 80 bar/1160 psi. Probably 70 bar/1015 psi of that was lost in a matter of a couple of minutes.
Total dive time was 10 minutes.
This WAS a badly blown o-ring, but it was a matter of a minute or two to take out almost half of her air.

What I learned from this was pretty much that I will do the EXACT same thing if It happens again, especially if its as bad a leak as this one was;
1. Donate an alternate air source
2. Shut down the freeflowing tank
3. Abort the dive safely.

If theres doubles or multiple tanks in other configurations it may be different, but for single tank dives, Ill just get an alternate air source to the person in need and abort the dive ASAP.

I had kept an eye on my buddy (as I think everyone should with theirs) for the duration of the dive so I know for a fact that this was not already leaking as we got in.

 

[Doubler]

Good job Tigerman and a good call.

 

[theduckguru]

Im posting this in this section as ive seen it come up in other threads on the board.

August 2009 - Sharm El Sheikh, Egypt (~40c/105f air temp)
Were jumping in for some manta ray action for our third dive of the day. We actually spotted one from the boat so we jumped in and followed it for a few minutes, ending up at around 20m/65 ft.
When I look back at my buddy I think shes having a way big exhale, but it last too long and she turns around looking for the weird sound coming from behind her and I realize theres a REAL major leak from her tank valve. I get closer to her and offer my octo, but she dont realize whats going on as she cant see the bubbles and think its a speedboat or something she explains to me later.
I signaled for her to stop, look at her pressure gague and take my octo before I shut down her tank valve and we start to get closer to the reef and ascend as we where pretty far away from the reef out in the blue.
We never got noticeably stressed or anything, so from that point of view it was just a perfect air-share ascend drill.

My buddy was a small woman that usually use about half the air I currently do.
I came up with 30 bar/435 psi less than I jumped in with while she had used 80 bar/1160 psi. Probably 70 bar/1015 psi of that was lost in a matter of a couple of minutes.
Total dive time was 10 minutes.
This WAS a badly blown o-ring, but it was a matter of a minute or two to take out almost half of her air.

What I learned from this was pretty much that I will do the EXACT same thing if It happens again, especially if its as bad a leak as this one was;
1. Donate an alternate air source
2. Shut down the freeflowing tank
3. Abort the dive safely.

If theres doubles or multiple tanks in other configurations it may be different, but for single tank dives, Ill just get an alternate air source to the person in need and abort the dive ASAP.

I had kept an eye on my buddy (as I think everyone should with theirs) for the duration of the dive so I know for a fact that this was not already leaking as we got in.

It would be interesting to know if the seals were Viton or Buna since you were in some pretty hot temps on deck.

 

[TSandM]

So it was the yoke o-ring that went? Or something in the first stage? Or an o-ring where a hose attaches? Could it have been fixable?

 

[ScoobaDooba]

If you shut the tank valve off with a broken O-ring, won't water get into your first stage port?

 

[Tigerman]

So it was the yoke o-ring that went? Or something in the first stage? Or an o-ring where a hose attaches? Could it have been fixable?

It was the yoke o-ring that went (it was pretty much split into to o-rings rather than one) and I didnt really see it as fixable and given the damage the o-ring had i doubt it would be.

As for the material of the o-ring, I wouldnt know as I dive DIN tanks myself with my own regulators.

As for water into the first stage or not, that was not of my primary concerns considering how quick the air was disappearing.

However, if I where to shut the tank down, loosen the first stage and re-attach it that would pretty much flood the entire reg setup with a small ammount of water, wouldnt it? That buy itself might not be a big issue for the particular dive, but it would require servicing afterwards.

 

[buddhasummer]

If you shut the tank valve off with a broken O-ring, won't water get into your first stage port?

probably, but this would be at the bottom of the list of concerns at that particular juncture.

 

[openmindOW]

Thank you for sharing your experience with this Board, Tigerman.

You handled things very well. Congratulations.

Lesson: Dive with a buddy!

I have a number fo DIN regs. Could someone here shed light on the possibility of a catastrophic air losss with a DIN? What happens if the DIN o-ring splits?

 

[TSandM]

If the DIN o-ring were to go, you would have a steady, large leak, similar to what Tigerman describes. It is said that this is less likely with DIN setups, because the o-ring is captured. I don't know if that is true in practice -- I have never had, or seen, either o-ring go during a dive.

 

[Couv]

Well done Tigerman. At first I was wondering why one would shut down an air supply that was working, but on second thought-if no one is breathing from it, why put up with the distraction. You could always turn it back on if need be.

Usually when a yoke o-ring blows, it is because the yoke was not properly installed, i.e. misaligned sealing surfaces and that could be the case here. However, your description of the discrepant o-ring leads me to believe that perhaps the seal was damaged prior to the dive. Probably on the previous regulator installation someone "gorillaized" the yoke knob/screw. Also possible could be the wrong size o-ring or wrong material (too soft) was used.

We are taught to inspect that o-ring in Basic Scuba class, but I have to admit I am guilty of just making sure it is there quite a few time. Also, I'm guilty of not paying the proper attention when installing the yoke onto the valve and consequently having a blown o-ring when entering the water.

The bottom line is someone got complacent either with the o-ring installation, inspection, or yoke installation.

Thank you for sharing this experience.

Couv