Suddenly no air from 2nd stage or Octo; tank at 2800 psi

[Apecks]

I dove twice yesterday and didn't have a problem; yesterdays' dive was first after professional servicing by someone I've not used before.

Did you not ask the shop that serviced them what was the problem? Sure I would have wanted to know before jumping back in the water :shocked2:

 

[DandyDon]

Sounds like classic 1/4 turn open to me. Seen it once, had it happen to me once this year when the boat captain checked my air. Got a member of the group to open it for me so I could continue the dive. Have since drilled in the water with opening my BC cummerbund so I can push my tank up and over far enough to reach the valve myself.

Look at your pressure gauge and take a few deep breaths before splashing and it never will.

I don't think that is universally true. I don't think it shows on my reg, but - I don't remember actually testing that. Have you on yours? All my regs and tanks are off for servicing or I'd do it now. Hehe, maybe I'll do a Vimeo vid when they get back. At any rate, I wouldn't trust the approach fully.

My regular bud & I like ours all the way! We stop at 20 ft while he works on his ears, we do a spin around final gear check, and make sure the valves are all the way even if a sneaky boathand played with them while we were getting ready to splash. Once, he turned mine all the way off on deck, and I was amazed since he turns screwdrivers every day - but I still liked it better than 1/4 on, as I knew before the splash.

If it is not a valve issue, which I believe it may very well be, return it to the shop that just serviced it. The greatest number of reg issues seem to happen immediately after some sort of "professional servicing".

Yep. We're certainly going to test all of my regs to 80 ft in New Mexico before we take them to Cozumel...!

(Hoping this isn't too hijack-y) In my PADI OW course, it was explained that the 1/4 turn back made it quick and easy for one's buddy to confirm that his air was fully on during the pre-dive check. The idea is that the diver opens the valve most of the way and his buddy does the final fractional turn to finish the job and confirm it's fully open.

I, for one, would rather open the valve all the way myself and trust that I've done it right, but I suppose I can understand a conscientious buddy's desire to know that he's checked my setup thoroughly. One would think that his attempting to turn the valve and having it fail to budge would reassure him. Maybe the 1/4 turn is to reassure buddies with weak arm strength that the valve isn't stuck "off." (Then again, that's what the SPG check is for...)

I think that Padi has officially stopped the 1/4 turn in OW class, subject to Instructors adopting their updated approach. Never heard that one before. "...his buddy does the final fractional turn to finish the job and confirm it's fully open." So you were taught to go all the way open, after the buddy check?

As I said, we like ours all the way, with all the way open being the intention. On our buddy checks, we close it 1/4 turn, then open it back up all the way.

 

[ScubaSteve]

I was asking because what I am seeing may be from an open and then closed tank. I have no idea how much air the lines hold so I am in no way suggesting people do this and pass on the buddy check (no blindly accepting anything suggested). THAT is how you make sure your tank is open (assuming your buddy knows what open is ).

Well, you obviously have more experience than the rest of us so I'll defer to your experience. I do, however, have doubts that every computer would do what you're noticing so I wouldn't advise people to rely blindly on that.

R..

Posted via Mobile Device

 

[DandyDon]

assuming your buddy knows what open is

Well, there was my exception from a home buddy who works with tools every day - and is good at his crafts.

And the times I saw a diver choke on the way down the Belize Blue Hole because a deckhand had closed it then opened it 1/4, or when a Captain did mine that way in Cozumel.

My way is remaining All The Way if you want me happy. And tipping

 

[cowdog77]

I was asking because what I am seeing may be from an open and then closed tank. I have no idea how much air the lines hold....

~~~~~~~~~~~~~~~~~~~~~~~~
Interesting point.......I'm wondering about how much I could get out of an "opened then closed" valve....? One breath, half a breath?

 

[Deefstes]

I'm with you. I've never had anyone explain why the 1/4 turn back. If anyone has a valid reason, let us hear.

The explanation I was given was that the skipper, DM, your buddy (or whoever) might try to open your tank valve just to double check that it's open. Because it is already all the way open it wouldn't budge and they might think it is in the closed position so they apply more force, damaging the valve.

Secondly, some people still don't get "righty tighty lefty loosy" - but for them there's really not much help

Next point, regarding Devondiver's comment about the SPG. If you do a proper check, consisting of this set of steps, you will never dive with a bad SPG (unless it fails mid-dive):

...

This seems long, but it takes seconds and makes sure that your SPG is as good as it will ever get. I did this ever since I saw an SPG stuck at 1200 psi with no air in it.

I remember reading a very interesting write-up by Richard Pyle on the events leading up to him getting bent pretty badly in Palau. There were a number of things that went wrong so blame can probably not really be placed on one single thing but one of the problems were that his SPG got stuck. This check of yours would probably have showed that quite clearly before the dive.

Does anyone know where that write-up is? I'd actually like to see it again.

 

[vladimir]

I remember reading a very interesting write-up by Richard Pyle on the events leading up to him getting bent pretty badly in Palau. There were a number of things that went wrong so blame can probably not really be placed on one single thing but one of the problems were that his SPG got stuck. This check of yours would probably have showed that quite clearly before the dive.

Does anyone know where that write-up is? I'd actually like to see it again.

http://www.scubaboard.com/forums/accidents-incidents/173275-not-within-realms-sanity.html

 

[drbill]

Not going to read through the entire thread, so this may already have been mentioned.

A similar thing happened to me several years ago when I descended to about 80 feet on a fresh tank. At about 3 minutes into the dive I exhaled and tried to take in another lung full of air. Nothing from my main second stage. Nothing from my secondary second stage. Nothing from my tertiary second stage (I DO believe in redundancy). SPG read 0 psi.

The cause... a particle from inside the tank apparently fell directly into the dip or debris tube on the bottom of the valve. It stopped ALL air flow from the tank. Once the tank was re-opened and inspected, it has worked fine for many years.

The reason it happened? Other than the curious debris particle that shouldn't have been inside the tank to begin with, it may have been due to a head-first descent to depth. Ever since then I have done sky diving descents with my body horizontal and appendages flared out.

 

[blue steal]

A similar thing happened to me several years ago when I descended to about 80 feet on a fresh tank. At about 3 minutes into the dive I exhaled and tried to take in another lung full of air. Nothing from my main second stage. Nothing from my secondary second stage. Nothing from my tertiary second stage (I DO believe in redundancy). SPG read 0 psi.

fftopic:
Hey drbill, what did you do next. I'm curious. 80 feet, no air ..........that would get my attention..........
:dropmouth:

 

[ScubaSteve]

I am fairly certain he would have just breathed off his second tank