Poll: Regulator failure requiring service during recreation diving

[herman]

Bonaire a couple of weeks ago, 2nd day of diving, free-flow during second dive, started slowly & gradually got worse to the point I was losing air very fast. Had to abort dive. Took it in to a shop (Bruce Bowker). IP was at 160 (too high) but wouldn't adjust and stay stable. Regulator was recently serviced (last November) and was used on 2 dive trips between service and the Bonaire trip. Regulator was new in 1995, serviced on average every 18 months, in very regular use and never presented any problem whatsoever.

So as not to waste any dives and as Bonaire prices are a lot better that here in Brazil I bought a new reg set instead of waiting for it to be serviced (24 hours) so I could get straight back to the beach. However, if I'd wanted, just about any of the local repair shops could have serviced the 1st stage and got me back diving next day.

My only concern now is that when I got home I put the faulty reg in for service at the shop that did it last November and there is absolutely nothing wrong with it. IP is totally stable and easily adjustable. 1st stage (Aqualung/USDivers Cousteau) uses well-known parts. It's a diaphragm model so it's not a question of anything like sand or salt getting in to it and the main adjusting spring is in perfect condition - no corrosion.
So, absolutely no explanation.

I had a Phoenix (the same internal parts) doing something similar on Bonaire a few years ago. Some times the IP was perfect and others is was all over the place. I swapped to another reg but back home I found a very small piece of trash...don't really know what it was or where it come from in the HP chamber. Appearantly it was moving around and from time to time would get in the HP seat and cause IP problems and when it was not in a "wrong" place, there were no issues. Once it was removed, I had no more issues with the reg. The piece was so small it could have easily been blown or dropped out during dissambly in which case I would have never found the issue.

 

[Nemrod]

I had a Phoenix (the same internal parts) doing something similar on Bonaire a few years ago. Some times the IP was perfect and others is was all over the place. I swapped to another reg but back home I found a very small piece of trash...don't really know what it was or where it come from in the HP chamber. Appearantly it was moving around and from time to time would get in the HP seat and cause IP problems and when it was not in a "wrong" place, there were no issues. Once it was removed, I had no more issues with the reg. The piece was so small it could have easily been blown or dropped out during dissambly in which case I would have never found the issue.

I was going to suggest the same thing, that or a bad crown block (scratch, corrosion etc.) I too had two regulator behave oddly with rising IP. One of them I had cleaned and replaced all of the O rings etc. I had cleaned the inside of the balance chamber in the crown block with a cotton swab. Apparently a small cotton fiber remained behind after ultrasonic cleaning because upon taking it back apart I found the fiber wrapped around the o ring.

Another behaved the same way, some years back. I kept cleaning and replacing the O ring in the crown block and replacing the HP seat and checking the volcano orifice for nicks (another possibility, a worn or nicked volcano orifice) and I just could not find anything. I finally replaced the crown block with a new one. Whatever, the issue was gone and the regulator would then lock IP like a steel vault.

N

 

[antattack]

Two failures, both right after servicing (different shops)
1. One of the O rings on the spool that connects the reg to the hose was damaged. Went from no problem, to bubbles, to a shower of bubbles in about five minutes.
2. Serviced the reg, got in the water, free flow. Mis adjusted.