Manifold failure - what should you do?

[Patoux01]

aj has lost i believe two sets of doubles out of the back of his truck on the highway.

How does one manage to do that?

 

[The Chairman]

How does one manage to do that?

My thoughts exactly. Unless he's been involved in an accident, I just can't imagine one, much less two. I do know a guy who flipped his truck with three sets of doubles and 4 singles in it back around 2001. The insurance company replaced all the tanks without a thought. Only three of the tanks passed a subsequent inspection.

 

[PfcAJ]

Tailgate didnt latch. Since remedied.

Manifolds are robust. Regs are not. An old friend of mine had his doubles fall over on a boat. Snapped the DIN tube.

Another anecdote, a friend hit a stage bottle on a rock and it dislodged the burst disk. All he got was a tiny little fizz and was able to fix it with a wrench and carry on.

As far as being able to tell what side a leak is on, even with a baby leak you can tell. Furthermore, it makes sense to stop while you're attempting to diagnose. Being preoccupied with your dwindling gas situation takes up a chunk of mental bandwidth, opening the door for nav errors, separations, gear getting snagged, etc.

Stop. Think. Act

 

[The Chairman]

Even with a baby leak you can tell what side it's on.

Baby leaks are usually far easier to determine where they are, even behind your back. An extruded o-ring on the inside tank neck is stupid hard to figure out unless you can get your fingers on the neck. Isolate and work from there is the only policy for me.

Obviously, this is not so problematic on side mount. I can eye either tank/reg assembly and act accordingly. They're already isolated, so no issues there.

 

[PfcAJ]

You've had an extruded tank oring on a dive?

 

[The Chairman]

Me? No. I've seen two. One on a set of doubles and the guy went to the wrong post to shut it down after isolating the leak. It shot from left to right, so it appeared that the right side was leaking. We were just on the deck of the S Grove. I think there's a thread on it somewhere here. Probably about 2003 give or take. We called the dive and went back to the boat.

The other began as a a fizzy O-ring when we splashed. She reached back to tighten her reg and apparently that was enough for the o-ring to pop out. I've never baby blues quite that wide before. She got back on the boat, got another tank and we went diving.

Now, I've seen far, far more regs leak to the point I couldn't begin to count them. The tendency is to dismiss tank leaks as highly unlikely. While some may be overly confident that they can not make a mistake, I am not so inclined. It takes a brief few seconds to isolate and maintain the integrity of my gas supply. I just don't see a downside to doing that. I won't ascribe to some false efficiency to short cutting that step. I don't know a single tech instructor who teaches differently either.

 

[PfcAJ]

I see it as you're shutting down the isolator which doesn't do anything to preserve your gas supply in the extreme majority of cases.

Now, if you shut down a reg and it doesn't stop, sure, isolate then sort out your business.

Every tech class I've been in has done it like that.

 

[tstormdiver]

I know someone who cracked their manifold while scootering in a cave alone. He unfortunately, hit an outcropping, barely missing his head. He said what he did was shutdown both valves simultaneously & still had a leak. He then isolated the cylinders. He then reached back to feel where he thought the leak may be coming from & confirmed it with his SPG. I don't remember which side he said it was, but isolated, if the SPG doesn't move, the leak is on the right, if the SPG shows a drop in pressure, then the leak is on the left. He found out where the leak was & breathed that regulator (he was going to lose it any way). When that cylinder ran dry, he switched to the good cylinder. He barely had enough gas to get to his dropped stage to get out of the cave.

 

[Dive Right In Scuba.]

I see it as you're shutting down the isolator which doesn't do anything to preserve your gas supply in the extreme majority of cases.

Now, if you **** down a reg and it doesn't stop, sure, isolate then sort out your business.

Every tech class I've been in has done it like that.

Yes, that is how I was taught by all the agencies with which I have trained, and that is how I teach it myself, but I do know of people who do it differently, so the idea is not that isolated. (Sorry about the pun.)

When I teach a class, I come up behind students, put my primary at the point I want the leak to be, and purge to create the sound. Students usually get the right one immediately, but sometimes they don't. Some agencies require that you do an entire valve drill within a very short period of time. PADI requires 45 seconds at even the most beginning level. I got it down to about 35 seconds when I was becoming a tech instructor. The only way I could do that, though, was using both hands at once. While working the right post with my right hand, I would be shutting down the manifold with my left. If you can do something like that, you will only lose a few seconds between shutting down the wrong post and closing the isolator.

 

[Kevrumbo]

Hi Everyone

Recently i was talking to another tec diver and we where discussing regulator and manifold problems.

We agreed about all procedures for free flowing regs but when we got onto manifold failure his idea is to initially close the isolator. work out where the problem is commng from and then just breathe the reg from that side no matter what.

I said that i agree to close the isolator, work out where the problem is coming from. But then is i would not breathe that reg i would also close that reg valve to save that gas. Maybe the problem could be with first stage and then i could reopen the isolator giving me access to all of my gas again. However, if there was a leak from a burst disk or the manifold bar then i agree to breathe that side down.

Can someone help me out if i am missing something? What would you do? Surely i have the correct precedure?

My Best Regards
Daniel Dilley

The two main objectives are: Determine which side the failure/leak/malfunction is actually occurring, and whether it is due to a post failure or a manifold failure.

Quick Overview of The 9 Failures as follows:

Right Post Failures: Either Fixable (#1) or Non-Fixable (#2).
Right Side Failure discovered in general vicinity of Manifold Crossover to Isolator Knob (#3).

Left Post Failures: Either Fixable (#4) or Non-Fixable (#5)
Left Side Failure discovered in general vicinity of Manifold Crossover to Isolator Knob (#6).

Mistakenly perceiving the Failure on the Right Side, when it's really on the Left (#7).
Mistakenly perceiving the Failure on the Left Side, when it's really on the Right (#8).

Absolutely have no idea where the Failure is . . .(#9) -->Isolate & take Long Hose donation from Buddy and abort dive smartly. . .