Any recent failures of "cave filled" tanks?

[Mark Michaud SELAUSAR]

You will find, when the DOT report comes out, that the recent cylinder explosion in Florida was due to a "cave fill" and virtually every safety protocol was violated.

That's kinda vague. Do you have any firsthand info on this?

If it is the same one I remember, apartment, I have pretty good information (from 4 sources that should know) that the tank had been stolen and the person was suspected of stealing gear from several shops, where, he had been employed. I also heard it had been dropped but the deceased and that he had been the one to overfill it. That bottle was an aluminum 80 and not steel. The reports stated it exploded and debris was as far s 75'. That is what aluminum, not steel, does when it fails. But, that is what I have heard and it is not quite as vague as your post and may be totally unreliable. Wait, there is the listed article below. Oh yeah. Maybe not so unreliable.

So let's post something with substance instead of innuendo, because it really doesn't add anything except, "I know something you don't" and we really don't need that.

http://www2.tbo.com/news/breaking-n...man-dies-after-scuba-tank-explodes-ar-256967/
Police: Two scuba tanks found at explosion scene were stolen - St. Petersburg Times
http://www.tampabay.com/news/public...urg-scuba-tank-blast-turns-to-missing/1191615

 

[j2s]

Thank you Spd135...

 

[Leadking]

Just wait for the DOT report!!

 

[bigrich954rr]

I have two sets of LP95's that are from 1970's that have always been filled 3600-4000psi. They pass hydro everytime. Overfilling does not shorten LP tank life. Failure to use LP tanks, or failure to take care of LP tanks might. Don't forget, before DOT got upset. OMS used to claim in their marketing, "guaranteed for 10,000 Fills at 4000PSI". And I believe it.

I've been in the diving industry for coming up on 20 years. My partner has been in the diving industry for 40+ years. Neither one of us can ever recall a fatality from a cave filled steel tank explosion.

What do you mean Failure to use LP tanks?

 

[mathauck0814]

Steels? I don't worry about overfilling or handling. AL40s with high O2 blends, I try to be a little more careful, but then you shouldn't have O2 at those pressures anyway.

 

[Akimbo]

I have two sets of LP95's that are from 1970's that have always been filled 3600-4000psi. They pass hydro everytime. Overfilling does not shorten LP tank life...

I don’t question your basic premise but there is a caveat. It depends on the cylinder design. Specifically how weight-critical the design priority was, meaning the engineer had to reduce the wall thickness/safety margin and/or opt for more temperamental high-strength alloys to achieve desired buoyancy characteristics. A cylinder with a lower weight to storage volume ratio is less likely to perform as well as your LP95s over time.

Industrial gas cylinders almost never fail hydro, but their weight to volume ratio makes them way too negatively buoyant for Scuba — it isn’t unusual to see cylinders born ~1910 still delivering gas. The other extreme may be some of the HP cylinders on the market that are designed much closer to the margin and have reported an unusual number of first-hydro failures. Granted, some may be caused by heat-treatment issues and there hasn’t been enough time to see if cyclic fatigue is also a contributor. Overfilling any pressure vessel will increase cyclic fatigue, the question is at what point that becomes an unacceptable failure rate at hydro.

I simply point out that your experience, though not uncommon, may not apply to every brand, model, or production run. Also, this is an international forum where cylinders built or tested to different standards may not perform as well.