From TDS

"Divers


Here is a little test I did at Eagles Nest cave on Feb 12th for a small article to be placed in issue 17 of Advanced Diver Magazine.

The question I wanted to answer was:

How much time would it take to empty a full aluminum 80 cuft cylinder from 3000 psi to 0 for the following situations and would depth affect the times.

1. Failed Burst Disk
2. Failed HP Hose
3. Failed LP Hose
4. Free Flow high performance regulator 2nd stage.

I completed the test on the surface (0 feet) with 4 aluminum 80’s and a Zeagle D50 regulator.

Here are the results

1. Failed Burst Disk = 72 seconds
2. Failed HP Hose = 22 minutes
3. Failed LP Hose = 83 seconds
4. Free Flow High Performance Regulator = 255 seconds


I then repeated the test at 4 atm’s / 99ft

1. Failed Burst Disk = Same within a second or 2
2. Failed HP Hose = Same within a minute
3. Failed LP Hose = Same within a second or 2
4. Free Flow High Performance Regulator = 155 seconds

I then repeated the test at 8 atm’s / 231ft

1. Failed Burst Disk = Same within a second or 2
2. Failed HP Hose = did not complete due to time restraints but would assume it would be with a minute difference
3. Failed LP Hose = Same within a second or 2
4. Free Flow High Performance Regulator = 91 seconds

The results show the small amounts of time a diver would have to solve a major equipment failure while at deeper depths.

The question I post for you is

What would be the best procedure to follow if such an equipment failure occurred to you and why?

1. Isolate manifold
2. Turn off affected post
3. Dive independents
4. Other answer

Next time you’re in your rig, conduct a test on yourself and your buddy by doing a shut down drill. Not cheating estimate in seconds how long it takes you to shut down you manifold.

By the numbers given above, estimate how much gas you would have lost, would you have enough left even if you where following the rule of thirds or half + 200.

The answers will affect the finished article.

Thanks for your responses

Curt Bowen"