Legality of "cave fills"

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

Not mine. I like to win if I don't have to put much effort into it.
I’ve met lawyers like that as well.

They write wills, oversee real estate transactions, honest work.
 
If I was a certified cave diver that enjoys the benefits of "cave fills"...... which I am not....... I would ignore this thread and let it just go away.
 
Burst discs are rated to blow at the test pressure of the cylinder. Not very accurate devices though

They make a mess if they blow when the cylinder is in a water bath

Also make a mess if a storage bank (350 bar 50L) cylinder burst disc goes when the cylinder isn't secured. They spin around like a break dancer and take out everything in their path. Strangely fun to watch
 
Not mine. I like to win if I don't have to put much effort into it.
I'm talking personal injury / tort lawyers. They are the scum of the earth.
 
Burst discs are rated to blow at the test pressure of the cylinder. Not very accurate devices though

They make a mess if they blow when the cylinder is in a water bath

Also make a mess if a storage bank (350 bar 50L) cylinder burst disc goes when the cylinder isn't secured. They spin around like a break dancer and take out everything in their path. Strangely fun to watch

I have never seen so many people get off the floor as fast as when a burst disc blew in a tank at a dive shop. It was upright on a tile floor and had the old-style burst disc holder that blew air at right angles to the axis of the tank. It fell over, of course, and then rolled until the air stream was parallel with the floor. Then it started to spin at high speed and bounce off other stuff, zig-zagging around the room. Everyone climbed everything in sight to get out of the way. (Me? I jumped up onto the corner of a glass display case.) It was pretty amazing to watch, but not fun. Also amazing is just how well motivated people can climb just about anything. It was lucky that it pretty much stayed on the floor because it never happened to hit anything that could launch it.

The new style holders that fire in opposing directions are *much* safer when they blow. Noisy, but not exciting. Sometimes, boring is better. This is why we're taught not to accept the old-style disc holders when doing a VIP.
 
Don't assume that a cylinder behaving like that will stay on the floor. The write-up on how a firefigher was killed when one went airborne is pretty sobering. https://www.cdc.gov/niosh/fire/pdfs/face201810.pdf

But if the burst disk nut is in place, the tank _will_ just sit there (making lots of noise).

The guys at this fire dept decided to drain their (full, out of hydro and corroded) scuba tanks by removing the burst disk nuts. What happens when one does that is not exactly what I'd call an "accident".
 
I'm just saying that once it starts converting potential energy to kinetic and physics takes over, regardless of how it got that way, it's not a safe assumption that a moving cylinder will remain at floor level, especially if it hits something and causes additional damage (like shearing off the valve).
 
Depends on what disc is in it...
So you'd put a higher-rated disk on an LP intended for cave-filling? Just enough to cover the pressure of the cave fill, or substantially higher?

The risk of doing that is that the tank itself blows, but that's a risk you've assumed when you overfill it. On the other hand, if you weren't going to cave-fill it deliberately, presumably you'd be want a burst disk appropriate for its rated pressure, right?

(Keeping in mind they're imperfect.)
 

Back
Top Bottom