1st stage of regulator failed in close position - new diver freaking out a bit :)

[clownfishsydney]

I have seen cases where a tank valve was fully opened (at least the handle did the normal number of turns) but it really was not open. In these cases, the valve insert (not sure of the correct name) was so dirty that it did not move outwards when the valve was opened. The tank pressure at the start of the dive and when shallow was sufficient to hold it open and let enough air through to breath.

Once the tank pressure dropped and the diver was at depth, there was insufficient pressure to overcome the insert and the diver got no air (probably really did, but it appeared to be nothing). Once she ascended a bit, it worked better.

Like most others, I think it was probably the valve, either not fully opened or faulty.

As you were using rental gear and a novice, you are probably not really aware of what the reg should normally breath like. If it was your own gear, you may have noticed something wrong a long time before.

 

[Uber Dave]

I thought first stages were designed to fail open. Am I wrong?

 

[cerich]

I thought first stages were designed to fail open. Am I wrong?

most are

 

[Dan]

just gave it a twist; though, I was just checking for a binary on/off. Not sure I was vigilant enough to notice partially open/closed. i was still in a state of shock.

It was so sudden. I didn't feel a hard breath pull preceding it. I had thought that breath pull above water before the dive would reveal a partially closed valve with a pressure drop.

Like I asked you in my post # 29, how many turns did you turn the valve on? I think it should be at least 2 full revolutions (2 x 360 degrees). "Just gave it a twist" is NOT considered a fully open valve, hence, pressure drop problem at that 25m depth.

 

[redacted]

I thought first stages were designed to fail open. Am I wrong?

most are

While generally true, I believe any 1st stage could also fail closed given the unlikely failure of the wrong part.

 

[cerich]

While generally true, I believe any 1st stage could also fail closed given the unlikely failure of the wrong part.

yup. Very few regs (and no recent ones that I am aware of) are not designed to fail open, that said I have had a reg that supposedly would fail open..fail shut (G500 first gen, the lever came off the poppet after they had changed the service kit to the molded white poppet versus the old blue with metal barrel poppet) I was diving with a SP rep..LOL.

 

[uncfnp]

While generally true, I believe any 1st stage could also fail closed given the unlikely failure of the wrong part.

But given an unliked failed closed in a way that shut off all air including the hp ports, would it then start functioning again upon ascent?

OP you may have said but did you test breath from the regulator after the failure and the return of pressure? Maybe back on the surface?

 

[tbone1004]

I have had a Poseidon fail closed which was a bit strange. Was showing pressure, but wouldn't give me IP. Something got stuck in the chamber. Pressed on the diaphragm with an allen key and all was well, never happened again. Was right after I paid to have it rebuilt, go figure. They have to be lubed basically everywhere because of the design, and I think it may have caught on a dry spot since it worked fine for the first couple of dives and then just stopped working. Was very strange indeed.

For the OP it is weird because he wasn't getting anything at the HP port which meant gas wasn't getting past the inlet of the reg. That means something wonky happened either in the reg filter, which would shock me, or the valve. I'm leaning towards either dipstick got clogged, or the valve wasn't actually all the way open and the differential pressure between ambient and tank wasn't enough to keep it open. Either way, highly unlikely the regulator, very likely something with the tank/valve combo

 

[Nemrod]

A diaphragm first can fail closed, a piston fails open. N

 

[halocline]

Regarding the "most expensive regulator" --really, I am talking from a pure placebo effect But key being to have my stuff maintained properly --i keep thinking it was a maintenance issue. Really liking the idea of a pony bottle (but have some concerns about how to fly with it to remote destinations --need to look into this).

All of these opinions have been great. Looking to regain my confidence a bit and book my next dive!

I'm so glad you are ok and are sharing this experience, but what you don't seem to understand is that your regulator almost certainly had nothing to do with your loss of air. If you had been diving with a brand new titanium atomic with extra bling, the exact same thing would have happened. My advice is to quit worrying about your regulator and just train yourself to always dive safely with a reliable buddy. Your story had a happy ending because you were able to share air. Yayyy...

Although this opinion is not shared by many others on this forum, I would also advise you to forget about the pony bottle. You're a new diver, all sorts of unexpected problems could come up. Things like sickness, disorientation, entanglement, getting lost, not being able to see, swallowing some water and having a near panic, a debilitating cramp, passing out, getting stung or bitten by some animal, etc. A pony bottle does NOTHING for you in those scenarios. Instead, for many new divers, and I have personally witnessed this on several occasions, it gives them the false confidence to be poor buddies and/or dive in riskier ways than they otherwise would. If you want to be a solo diver, fine, but get the necessary training and experience, and understand that no matter who you are, solo diving is riskier than team diving.

Okay, now the pony-lovers can blast me.