Does this really ever happen? How often has /does a regulator actually fail?

How often has /does a regulator actually fail?

Not talking about an out of air situation.

I'm talking a situation where you have plenty of air in your tank and you simply can not breathe off your reg.

Also to expand on this, how many of these regs were actually maintained properly?

I have had a new reg begin to leak air on a dive and breath very wet. It only needed some adjustment but it shortened my dive because of it. I can certainly imagine it being much worse though.

I was under the impression that Regs were designed to fail open and not closed

Sonnylynnvick75:

I was under the impression that Regs were designed to fail open and not closed

Click to expand...

to quote Bill Murray from the movie STRIPES...That's a fact Jack! Unfortunately, some events evade failsafes.

While technically a failure of the LPI hose valve, there was the SiTech incident that apparently resulted in a plugged 2nd stage delivering zero air. Court Says No Recovery for Woman Who Saw Brother Die

Why this would result in a fatality is unclear to me (Octo? redundant air? shallow enough to CESA?), but it's a reminder that there are things that can shut off your air supply. A loose dip tub + tank debris + an inverted position has been known to produce the same effect.

the only failures I've had of any sort were right after they were "maintained properly" - the only one where I wouldn't have been able to breath off the reg was when the first stage fell apart when I turned the air on.

Diaphragm type first stages use a pin (rod) to unseat the HP volcano orifice in response to dropping intermediate pressure. If the pin were to fail then the upstream HP seat would be closed. It fails closed. How many times has this happened, I bet maybe once in the world though there are a few people around who manufacture a big deal over this, that said, a piston first is downstream and therefore conceivably in a make believe world, more reliable.

I have had a regulator that was tuned up by an "old Navy man" fail shut at 1,000 psi due to installation of incorrect parts.

I have one MR12 first fail after the IP diaphragm split open, of course it still breathed for a little while until all the air was exhausted from the tank. I was on independent doubles and deep. I switched over and surfaced.

I had one Tekna T2100 fail to breath on demand sufficient to maintain life, the pneumatic valve (a stiff diaphragm) for whatever reason was stuck to the regulator body and would not move.

Maybe a few other times I can think of if I thought long and hard.

N

Sonnylynnvick75:

I was under the impression that Regs were designed to fail open and not closed

Click to expand...

In general yes.

But there are specific failures (rare!) that can cause a catastrophic failure... which I define as being unable to breath from the reg, not just a free-flow.

Examples:

2nd stage issues:

• 2nd stage diaphragm torn or displaced, resulting in 2nd stage fully flooding and inability to breath from that 2nd stage.

• 2nd stage demand lever falls off or breaks. Falling off is more common, due to nylock retaining nut falling off the lever in a classic downstream 2nd, or improper installation during service. (I believe I have also heard about a lever falling off or having its "feet" disengage in a barrel poppet 2nd stage, which would again be a bad thing). Impossible to breath from reg, diver may believe they have gone OOA.

• Retaining pin in 2nd stage breathing resistance knob incorrectly installed, or not installed at all during service. Diver turns adjuster counter-clockwise underwater, knob falls out / is forced out of regulator by IP pressure, resulting in rapid loss of air.

• Hose rupture or separation.

1st stage issues:

• Retaining bolt on swivel turret is over-tightened during service, weakening the bolt. Bolt shears during dive, and all hoses attached to the turret lose air pressure.

• Yoke retaining bolt (the bolt holding holding the yoke to the 1st stage body) comes loose, yoke falls off during dive, causing first stage to separate from tank valve.

• In diaphragm first stage, diaphragm tears or fails (from failure to inspect diaphragm during service or from sloppy installation).

Inability to breath from the regulator due to first or 2nd stage failure is pretty darned rare, and is often caused by negligent service, based on the incidents I have heard about over the years.

I'm sure other folks can chime in with other failures.... again, catastrophic failures are rare, and in competently serviced regulator these failures should be so unlikely that they are almost not worth considering.... yet they have happened, usually post service.

NOTE: None of these major failures have ever happened to me in 38 years. I have had the more "typical", fairly "benign" failures such as slight free-flows, wet breathing, small leaks from various o-rings.... that type of failure. Nothing that was an emergency.

Best wishes.

A second stage can be damaged so badly that it falls apart or leaks excessively. The old orange sherwood second stage bodies (octopus) would crumble and fail. I've seen a hose explode underwater. It was super loud.

Also most commonly... th exhaust valve folds over making the reg breathe super wet.. some people might not be able to make use of it like this.

Jax:

How often has /does a regulator actually fail?

Not talking about an out of air situation.

I'm talking a situation where you have plenty of air in your tank and you simply can not breathe off your reg.

Also to expand on this, how many of these regs were actually maintained properly?

Click to expand...

Honest injun cross my heart I've had the misfortune of having this exact situation happen to me.
My regs are serviced regularly and in NZ my tanks are visualed every year and hydro'ed every other.
But diving overseas and i had the misfortune to use an ally tank that hadn't been dried propperly after a hydro -or something else that left ally oxide inside. So first off the computer started to fritz then it started to get harder to breath.
Then I had no air at all.I started to the surface and was then able to "sip" some air.Enough so I could do a safety stop and get up with no real issues.Once back home the regs were stripped and the primary filter was apsolutely clogged.