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

[GrumpyOldGuy]

Yes, but the root cause is something that started with the failure of something else not the regulator (root cause is in the Tank). This is no different than the tank running out of air and thus the regulator fails to deliver air but the regulator isn't the root cause of the failure in delivering air in both cases. The regulator in this case was doing its job no problem until a problem outside the regulator blocked the flow of air to the regulator and hence no air. The regulator hasn't failed internally at all, it will still work with a different full tank.

I agree the root cause would be the poor tank maintenance + wet fills (which go hand in hand since the LDS controls both).

The trigger event is going inverted.

However, the tank is in fact still delivering air, slap a fresh reg on it and it would work just fine. Slap the same reg on a good tank and it would not. Thus logically the reg failed.

 

[mathauck0814]

I think we're on to splitting hairs. The OP question was whether or not a [regulator] failure occurred where a fullish tank of gas stopped delivering gas to the diver. Seems it doesn't really matter what failed, it's counterintuitive given the message everyone receives in training (e.g., "this is safe - even when things fail, they're designed to fail open so you're never without air"). Tank or regulator - a gummed up filter that either prevents gas from passing or a jammed piston that won't cycle fits the bill whether the root cause is the tank or the regulator.

 

[randy88k5]

Really, I've never, ever ever seen nor heard of a regulator failing completely while on a dive. Can you give me an example of "some events" ? which evade failsafes. I'm not talking about hoses bursting or operator screw ups like those listed above. I'm not saying you're wrong but I cannot see how from a purely engineering design standard that a regulator fails COMPLETELY and in a CLOSED mode of op

In post 38 of this thread, I showed an example of where my father's regulator failed "closed" twice. The regulator was replaced after the second time, and the original sent to a consumer product safety lab. The problem was never definitively identified.

 

[GrumpyOldGuy]

I forgot to post, I had 2nd identical stage octo's fail to deliver air. My kids discovered both on pre-dive check right after having the regs serviced. It was not so much an equipment failure as a service snafu and neither one was capable of delivering air, reassembled wrong and never tested by tech.

 

[John C. Ratliff]

Here are some of the regulator malfunctions I've and experienced:

"Warm Mineral Springs Underwater Archeological Project, Florida, 21 Feb 75: &nbsp;Sonny (Cochrell) had a regulator malfunction at 90'. &nbsp;Poseidon reg (both 2nd stages and zapper for BC) wouldn't work ---> Buddy breathed w/Toni, turned tank off, then on again; regulator worked. They dropped from 90' ---> 120' in the process &amp; had to decompress according to the 120' sch."<br><br>Warm Mineral Springs Underwater Archeological Project, Florida, 1975, Poseidon Cyclon 300 regulator was being worn by a Florida State Senator, who was diving on the project getting a tour of the site. &nbsp;He was fairly deep (~60 feet) when he had a complete malfunction of this regulator. &nbsp;He turned and buddy breathed with his buddy for the rest of the dive, without interrupting the dive. &nbsp;It turned out he was an ex-SEAL team member.

I had my Trieste II (double hose regulator), which was a highly modified regulator, malfunction so that I could not breath through the regulator. This happened suddenly, after an exhalation. &nbsp;I simply switched to my MR-12 safe second and completed the dive. &nbsp;I had placed a deflector plate into the mouthpiece, and it had dislodged during the dive. &nbsp;It then found its way to my inhalation mushroom valve in the mouthpiece, and adhered to it via osmotic pressure. &nbsp;But this was far from a factory-modification, and it has never happened again (I used more cement to get it in place).

I do a lot of modifications to my regulators, and so take responsibility for those malfunctions that occur as a result. &nbsp;I had a Scuba Deluxe by Healthways malfunction after I removed the non-return valves from the mouthpiece. &nbsp;I could not exhale underwater with the unit; it turned out that my exhalation pressurized the main diaphragm (this is a double hose regulator) and it pushed against the mushroom exhalation valve in the case, effectively closing it so I could not exhale. &nbsp;I found that I needed to add an obstruction (a nut was cemented to the plate) to keep a distance between the diaphragm and the mushroom exhalation valve. &nbsp;Healthways, when they produced the next (and last) generation, the Scuba Gold Label, placed a metal tab near this mushroom to keep this from happening.

I had a MR-12II by Mares freeze in a freshwater lake at about 38 degrees F. This produced a free flow, but not a radical one, as I terminated the dive just after this happened. Because I was diving in cold water, I subsequently sold that regulator.

I believe I heard &nbsp;that one pararescueman suffered a low pressure line parting from the first stage of the regulator during a parascuba jump in the 1960s. &nbsp;But that was caused by the parachute riser being caught on the regulator second stage, or the hose itself, during deployment of the parachute.

I investigated a diving fatality where a diver was using a regulator which was drawing over 8 inches of inhalation resistance due to not being serviced in many, many years (this was just part of the reason for the fatality--diver fatigue, which had multiple causes). &nbsp;It was a Scubapro 109 second stage, which he had screwed in as tightly as possible (second stage adjustment) to keep it from leaking.

Those are the regulator malfunctions I've either witnessed or had happen to me in 55 years of diving.

SeaRat

 

[bakodiver391]

I have seen 1 first stage fail closed. The soft HP seat came adrift and completely blocked the orifice. This was a defective part on a new regulator and was returned to the manufacturer. Admittedly, 1 incident in tens of thousands of dives witnessed is not a high rate of failure, but the consequences are so dire that I will not dive without a completely redundant air source.

 

[BoltSnap]

I will not dive without a completely redundant air source.

Does this mean a totally different regulator (FS and SS) for you, a pony bottle?

 

[flots am]

But this isn't a regulator failure, this is Tank failure to deliver air to regulator. We are talking about regulator failure as far as I know.

If you have a full tank, try to breathe and get nothing, you really don't care if it's because the reg failed or the tank valve is clogged or because crap from the tank clogged the reg.

"No air" is "No air" regardless of the cause.

flots.

 

[BoltSnap]

If you have a full tank, try to breathe and get nothing, you really don't care if it's because the reg failed or the tank valve is clogged or because crap from the tank clogged the reg.

"No air" is "No air" regardless of the cause.

flots.

This isn't the "spirit" of the question. The OP gives me the impression that they want to know how reliable the regulator is and how often it fails due to inherent problems in the design of the regulator. It isn't asking about external factors as I understand it. Perhaps the OP needs to clarify what they are after and what exactly the parameters of the failure they are talking about.

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.

 

[flots am]

Originally Posted by 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.

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That's exactly what you get with a clogged tank valve.