Tank valve failure

[scubadds]

This is a near miss story, but I felt If I shared the story someone could benefit.

A few years back, my dive buddy and I were on our second nitrox dive in the 110+ range. We were swimming away from the anchor down a ledge. I had over 1500psi left in my al80, I felt a slight resistance to breathing that made me uneasy, I gave a "I feel a little strang signal" and we headed back.

Instantly I had a dead regulator. Nothing at all, as if a ghost had turned it off.
I switched to a 19 pony and threw an out of air signal. Took my buddies pony and slowly swam back to the anchor and made a smooth slow ascent up the anchor line, his pony died at safety stop, then I finished mine down and came up slowly.

It went like smooth and was not scary.

In the boat we played with the tank knob and the reg charged back up to 1500psi.
I immediatly took it in, turns out a small piece of the valve had lodged in the valve and obstructed it. I never thought about a valve service, but I do now.

Anyway, my buddy was close and I would have been fine without a pony.
But I will never dive without a pony.
Hope this helps somebody.
Thanks
BT

 

[Wayward Son]

FWIW, I have the practise of getting my valves serviced regularly. If I buy a used tank, I'll have it done at the next VIP. Otherwise, I always have them done when the tank goes in for hydro.

My LDS generally charges about $8 to service a valve, depending on what parts are needed. $8 every 5 years is cheap insurance.

I had one valve fail during a fill. I got the tank used, and had it in for only the 2nd or 3rd time filling since getting it. When I picked it up George handed me a baggie with a few parts, including a bent stem, the part that the rubber knob attaches to. The tank had evidently been dropped or somehow taken a hard hit on the knob, bending this part. Enetually the O ring under it finally failed. After it failed during the fill he popped the valve off & serviced it, then filled the tank.

 

[PerroneFord]

I don't think I'd be interested in diving below 80 feet on a single tank. And as your story demonstates, a 19cuft pony may not really get the job done. I'd say sling a 40 or dive doubles if you're going to be going deep.

One question for you though. Is your SOP to go to your pony BEFORE seeking the help of your buddy? That seems somewhat backward to me, but I'm very new to all this. Especially in how pony bottles are used.

 

[scubadds]

For me yes,

It is not uncommon for vis to be poor or if vis is good a buddy is a little further away.
I find that your buddy is not always looking right at you.
If my pony reg is 8 inches from my mouth, I am putting it in.
I found the 19 to be adequate air in the circumstance.

 

[PerroneFord]

I found the 19 to be adequate air in the circumstance.

his pony died at safety stop, then I finished mine down and came up slowly

These two statements seem contradictory. Unless both ponies were used, you would not have been able to complete your stop.

 

[scubadds]

Knowing I had a spare pony, I did not do a immediate vertical ascent. I used his pony to swim along the ledge to get back to the anchor, then went vertical.
(If I were solo, I would have gone straight up and done a safety stop)
I suppose a bigger stage bottle would be ideal.
I dive a HP120 now. I am just trying to sling the 19 (vs a pony tamer type system), if it's not too cumbersome I would try a 40.
I just wanted to share a thought incident that I had never really thought about.

 

[PerroneFord]

I appreciate you sharing your incident. It did help me understand a bit more about pony use. Since many people choose to use them, it's probably good to learn about them.

 

[Diver0001]

One question for you though. Is your SOP to go to your pony BEFORE seeking the help of your buddy? That seems somewhat backward to me, but I'm very new to all this. Especially in how pony bottles are used.

I have something I call my A-B-C-D rule (explained in a bit more depth in this thread

First order of business is to secure the air-supply. That stands to reason. What you need to do depends on where your buddy is and what is faster and easier to secure at that moment. As a general rule--to which, of course, there are often more exceptions than you can shake a stick at--I would first use the pony. I should qualify that by saying that I'm also trained and experienced in using stages (which is how I would rig a pony) and I'm calm and goal oriented even when it's raining *hit. If you're not like that you may choose to act differently, I don't know. What's needed here is to think about it *before* it happens and visualize how you think you should respond.

Secondly (the "B") I would sort myself out, check gauges and what not and then ....

(the "C") sign to my buddy that my valve has a problem and I want to abort.

This isn't to say that my way is the right way or the only way. What I think is important is that everyone thinks about *their* way.

R..

 

[Sideband]

I've started using a 40cft pony recently. IMO, it makes sense to grab it first in an OOA situation wether actually OOA or a malfunction. That's why I brought it along in the first place. Going to a buddy and signaling and exchanging regs and all seems like a waste of time when I have the solution sitting 6 inches from my mouth.

Joe

 

[diverDano]

Nitrox at 110???...holy people...go back to the books.