First Stage Regulator Failure Rates

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joewr

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Hi, All,

Please, I would appreciate it if this would not devolve into an argument about regulator types. Please!

I’ve been looking for DATA about first stage failure rates, and have not found any.

if anyone has DATA, I’d appreciate it.

Confession: I’ve always used piston-type first stages, had them serviced annually, and never experienced a failure. But I have also never been on a dive when another diver’s regulator—of any type—failed.

Thanks!

Joe
 
You aren't going to get data. You will get folks who have an idea.

In the 90's my observation was diaphragm regs failed more often, due to how HP seats were made. I would confidentiality say they failed easy 5x more often than piston firsts. Now.. how the industry makes HP seats for diaphragm regs has changed and I would be surprised at any delta at all. I am excluding cone style HP diaphragm from that however, as I have observed a higher failure rate in them.

By you not wanting this to be a discussion of reg types, you are almost asking for a rate that means nothing without context
 
You aren't going to get data. You will get folks who have an idea.

In the 90's my observation was diaphragm regs failed more often, due to how HP seats were made. I would confidentiality say they failed easy 5x more often than piston firsts. Now.. how the industry makes HP seats for diaphragm regs has changed and I would be surprised at any delta at all. I am excluding cone style HP diaphragm from that however, as I have observed a higher failure rate in them.

By you not wanting this to be a discussion of reg types, you are almost asking for a rate that means nothing without context

Catastrophic failures or creeping IP?
 
Catastrophic failures or creeping IP?

Any DATA will be much appreciated. Not just anecdotes, but real DATA—graphs, charts, annotated lists, etc.

Thanks,

Joe
 
Any DATA will be much appreciated. Not just anecdotes, but real DATA—graphs, charts, annotated lists, etc.

Thanks,

Joe
ok.. you need to find either a manuf that is willing to share that with you (if they can, one reason that would be hard is that sometimes we see batch variation, that would skew your data horribly. Unless you are doing a degree in stats ( and what type of freak are they anyway?? :), stats scares most of us mortals) you need to better define what you are looking to learn and how) or a high volume repair facility that is willing to log so you can get that data.

PLUS- No individual diver will have enough sample size data to be meaningful anyhow, even me with having 25 years teaching tech, literally a dozen personal regs that entire time at any given time of various designs.

A repair tech at a shop that services volume ( i would look for sample size of over 500 regs as a bare min will be able to help, I would not look at shops that are heavy one brand, or again, skewed data and possibly agenda. (If an atomic dealer, are they gonna say that diaphragm is better?, or whatever brand and vice versa)

Even if you do all that, your data is still almost meaningless, because you don't have a base point on what MTBF in service is.. that MATTERS, a LOT.

Good luck!
 
This is what I have found.

During 2006 to 2015 there were an estimated 306 million recreational dives made by US residents and 563 recreational diving deaths from this population. The fatality rate was 1.8 per million recreational dives.

From: Buzzacott, P; Schiller, D; Crain, J; Denoble, PJ (February 2018). "Epidemiology of morbidity and mortality in US and Canadian recreational scuba diving". Public Health. 155: 62–68.

In 14% of deaths there was a regulator fault reported, and in 1% the regulator was misused. Subsequent testing of the regulators showed that most of the problems were caused by leaks resulting in inhalation of salt water, but in some cases there was excessive breathing resistance following a mechanical dysfunction. In a few cases the regulator failed catastrophically, or the hose burst. The difficulty of breathing from the regulator was often aggravated by other factors such as panic, exhaustion or badly adjusted buoyancy.

From: Edmonds, Carl; Thomas, Bob; McKenzie, Bart; Pennefather, John (2015). "Why divers die", Diving Medicine for Scuba Divers. pp. Chapter 34.

Using that data, I calculated that 0.25 deaths per million rec dives were caused by reg problems. However, they don’t discuss what the reg types were. Hence, my question.
 
Any DATA will be much appreciated. Not just anecdotes, but real DATA—graphs, charts, annotated lists, etc.

Thanks,

Joe

the data simply doesn't exist, you won't find it anywhere, you can ask everyone in the industry, it is simply not possible to provide data. Why? In order to provide reasonably accurate data you'd need the following information.
Total number of cycles of the first stage
Duration that the first stage has been pressurized
Run to failure

You can put a first stage on a bench and run it to failure and get that information, but how many times do you have to repeat that test to get any sort of meaningful data?
Some of the old manufacturers may have done that when they were first setting recommended service intervals, but I doubt it was done to something that could be peer reviewed.
In the review you cited above where you talked about leaks causing inhalation of water, that leak is on the exhaust diaphragm. Too many variables cause rubber to stick and it's impossible to get any data. Something could have gotten stuck in the body and wedged the diaphragm open, it could have seen a lot of heat/sun/chlorine and gotten sticky, it could have seen a really aggressive exhale that flipped the diaphragm through the holder, etc. It's not an annual service item either, but even if it was, you can't predict it. Anything you try to extrapolate out of that for regulator failure is useless because regulator failures that don't result in an accident aren't reported. I had one a few weeks ago, happened on the surface, it's not getting reported. I could tell you the last time that reg was serviced, but not how many cycles it had, how long it had seen pressure, etc. so I can't give you a failure rate on my own regulator, heaven forbid any information that is useful to publish.

I'm an engineer, I work with data all day, I'd love to direct you somewhere to get it, but there is no real value in having that data, and whatever the value is, it is paled in comparison in the cost of getting it.
If you service your regs annually, the likelihood of you seeing a failure is so near 0 it's simply not worth worrying about. Doesn't matter what kind of regulator it is.
 
I'm an engineer, I work with data all day, I'd love to direct you somewhere to get it, but there is no real value in having that data, and whatever the value is, it is paled in comparison in the cost of getting it.
If you service your regs annually, the likelihood of you seeing a failure is so near 0 it's simply not worth worrying about. Doesn't matter what kind of regulator it is.

I’m a (retired) chemist, and have worked with data most of my life, as well. So, I was curious about whether there was any data about reg failure the included the reg types. So far, no luck. That said, from what I’ve read, the failure occurred due to leakage—which would make it seem that the reg type was irrelevant. The other piece of missing data was whether the leaking regs had been serviced appropriately,

Bottom Line: until further notice (LOL), I completely agree with you that for any diver, proper servicing by a qualified tech is the best way to avoid reg failure.

Thanks,

Joe
 
There are way too many variables that would need to be tracked to get meaningful data about failures. Such as:

How the regulator was cared for by the user. Exposure to heat, cold, humidity, and chemical vapors between use. Exposure to sand, algae, salt during use. Rinsed appropriately, inadequately, or not at all after use.

How the regulator was serviced. Quality and durability of the rubber parts. Service interval exceeded or not. Service tech used correct size replacement parts and did not scratch or damage metal parts or not. Service tech tuned regulator correctly or not.

I think the only data available that you might find interesting is regarding regulator recalls.

Dive Equipment Recall Info at Scuba.com
 
Another way to mitigate first stage issues is to carry two on any dives where a CESA would not be easy.
 
https://www.shearwater.com/products/teric/

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