Regulator failure - timing in service cycle

[scott stanton]

I've only had 2 "failures", both were immediately after service. Not sure if we should consider them regulator failures or simply "service" failures:
1st was over 25 years ago and for 1st dive after service, 1st stage was leaking badly after being pressurized. Found to be loose nut securing yoke to 1st stage. Tightened before dive with no further issues.
2nd was 6 +or- years ago. Had regulators serviced before dive trip. 1st day of diving did 100' (+ -) wreck dive followed by shallow reef dive. Upon returning to dock, while carrying my gear I heard something fall to the ground. Turned out my primary second stage fell off the low pressure hose. Had no issues diving it (no noticeable leaking) but it was obviously loose enough to unthread with the boat ride & handling.
So both these failures are attributed to faulty service by the shop.

 

[AfterDark]

I've only had 2 "failures", both were immediately after service. Not sure if we should consider them regulator failures or simply "service" failures:
1st was over 25 years ago and for 1st dive after service, 1st stage was leaking badly after being pressurized. Found to be loose nut securing yoke to 1st stage. Tightened before dive with no further issues.
2nd was 6 +or- years ago. Had regulators serviced before dive trip. 1st day of diving did 100' (+ -) wreck dive followed by shallow reef dive. Upon returning to dock, while carrying my gear I heard something fall to the ground. Turned out my primary second stage fell off the low pressure hose. Had no issues diving it (no noticeable leaking) but it was obviously loose enough to unthread with the boat ride & handling.
So both these failures are attributed to faulty service by the shop.

To each his own, but IMO those aren't really failures. When the regulator can't be used without major service, IMO that's a failure. What the OP considers failures is unclear.

 

[Angelo Farina]

800 dives in 28 years of diving and I have only seen one failure. Don`t know the service history, but it was a Scubapro MK20 that blew apart at the beginning of a dive. A rather impressive failure in both sound and appearance. Sounded like a bomb and emptied the tank before the diver got out of the water, say 2 minutes. He had just gotten in was at about 15-20 foot. No injuries.

Interesting. I know that MK20 was subject to a recall and modification, as there was the risk of over-tightening the joke screw when reassembling after service. Resulting in rupture of the thread, I presume...
more info on the recall here:
UnderwaterTimes.com | ScubaPro recalls 48,500 MK20 regulators
Can you describe better the failure point?

 

[Perryed]

It split the body of the 1st stage pretty much down the middle. Not really wide open but about a 3/8 inch crack down the middle where the "A" yoke connected to the body of the reg. Exactly what you would expect from a failure due to severely overtightening the yoke retainer which can put a stress crack in the body. I have a MK20 and the first thing I did was have it sent into Scubapro to have that defect remedied. They do this with a newly designed yoke retainer.

 

[Divectionist]

What the OP considers failures is unclear.

I tried to loosely define it in the first post:
For the poll, it does not matter whether the reg failed catastrophically at depth or the failure was caught on dry land during a pre-dive check or with the IP gauge - let's consider any behaviour out of spec that is either a real problem right away, or a clear sign of the reg developing such a problem, as 'failure'. We can draw the line of IP gauge-caught failure, for example, at a creep that does not lock up close enough to the specified pressure.

So there are many shades of failure, but both instances you quoted are failures that were introduced by the service. The first may be one that would always be caught on land and is easy enough to fix, the second could have been a real situation. For reporting failures, anything out of spec goes. For assessing the potential severity, let's always assume the average diver that connects a reg and goes diving.

That said, the poll is starting to show some damning signs. Maybe the title attracts a disproportionate amount of people irritated by failure in conjunction with the idea of service, or it is just really that bad.

 

[Compressor]

Diving since 1984. I don't consider slight free flows major failures but I am not doing tech dives. If you count slight free flows a defect then I've had some here and there almost always mid service interval.

I text my regs when I pick them up at the shop. If I am not happy with their performance and how they "feel" I have the tech adjust them then and there.

Otherwise no major failures in my diving history.

I don't know how to service my own equipment.

 

[Nemrod]

An "old Navy diver" fellow insisted on servicing my USD DA, fortunately I pool tested it afterwards, it locked up at 1800 psi. He had installed incorrect parts, some from a RAM, in the first stage. I fixed it. The other was a first stage failure after service (by a retail dive store) at 80 feet of a Mares MR12. The HP diaphragm perforated and I exited stage left to the surface pronto. I fixed it. I generally service and repair my own equipment. N

 

[Divectionist]

The other was a first stage failure after service (by a retail dive store) at 80 feet of a Mares MR12

Your fellow aside, these cases of a reg being stuffed by a store are precisely those worthwhile understanding in more detail.

80ft/24m is getting to the deeper end for rec divers and with a bad combination of factors and a dash of panic, it may just end a life.

 

[Nemrod]

Your fellow aside, these cases of a reg being stuffed by a store are precisely those worthwhile understanding in more detail.

80ft/24m is getting to the deeper end for rec divers and with a bad combination of factors and a dash of panic, it may just end a life.

I brought the regulator into a well known at the time store in Houston circa 1984. It was the store I had purchased the regulator from. I was getting ready for a three day trip to the Flower Gardens Banks. Since the regulator was about two years old and had been stuttering I thought to have it serviced. Again, I have always serviced my own gear. But the shop had promised a free service and at the time I was well employed and quite limited in available free time. As you know the FGB are 70 plus feet. I am a free diver (or was) so the loss of a regulator, though not fun, at 70 to 80 feet was not such a giant deal, I went to the surface. Disassembly of the first stage revealed that it appeard, to me, that the diaphragm had been reused instead of replaced with new. The diaphragm had split or perforated and then tore beginning at the edge. A close look indicated that a sharp object, like a pick or Exacto knife blade, had been used to pry it from the stage body. It was also greased. Oh, there was also a scratch in the chrome from whatever had been used to pry it up.

Now that I am thinking, I had a similar failure on a Conshelf but it occurred within seconds of pressurizing. This one was nearly the same, the diaphragm was unseated. I suspect I had over greased this one myself (yep, I did it, bad me). I also, possibly, did not fully tighten the retaining cap down and while I had installed a new part I did reuse the phenolic slip ring. It appears the diaphragm slipped or squeezed inward and high pressure air found a way under it. This one is mine, I accept that I was hurried and not paying attention.

N

 

[mafi]

While I fully support the If it ain't broke don't fix it mentality (I am an engineer), I am always following the 1 year or 100 dives, whichever comes the first rule. I take good care of my regs but sometimes I am really surprised by what I see inside.