Low pressure hose failure

[49thdiver]

Greetings, first off I am very glad to be posting this message, and I thank my Buddy for being there when I needed him.
From the attached picture you can see a low pressure hose with swage and a hose barb. The hose did have a protector on it at the time I have since removed it to inspect the swage and hose. These two pieces are normally joined togeather for ever and ever amen, you would think. In this particular case however 20 minutes into the dive at 70 FSW, with about 800 lbs of air remaining turning my head to the right to see if my buddy was follwoing to the the ascent line, they decided to part company, something less than 10 seconds later I had NO AIR. This story has a happy ending, my compentent buddy was there as soon as he heard it go off, I am now the proud owner of a 19 cuft pony bottle with back up reg.

I dive a lot this set of regs has 200-300 dives, I look after them, there is no signs of wear or stress.

So far nobody I have talked to has ever heard of this happening before let alone why.
Any ideas comments appreciated.

Lessons Learned : Dive with a buddy, dive with a pony, tell your family and friends you love them and enjoy knowing them.

Peter

 

[300bar]

Seen this happen once before,with a new reg.
It seems to be rare but it does happen.

 

[cool_hardware52]

Greetings, first off I am very glad to be posting this message, and I thank my Buddy for being there when I needed him.
From the attached picture you can see a low pressure hose with swage and a hose barb. The hose did have a protector on it at the time I have since removed it to inspect the swage and hose. These two pieces are normally joined togeather for ever and ever amen, you would think. In this particular case however 20 minutes into the dive at 70 FSW, with about 800 lbs of air remaining turning my head to the right to see if my buddy was follwoing to the the ascent line, they decided to part company, something less than 10 seconds later I had NO AIR. This story has a happy ending, my compentent buddy was there as soon as he heard it go off, I am now the proud owner of a 19 cuft pony bottle with back up reg.

I dive a lot this set of regs has 200-300 dives, I look after them, there is no signs of wear or stress.

So far nobody I have talked to has ever heard of this happening before let alone why.
Any ideas comments appreciated.

Lessons Learned : Dive with a buddy, dive with a pony, tell your family and friends you love them and enjoy knowing them.

Peter

Good, aware teammate = Priceless.

Hard to tell from the pics, but it looks like the hose did not reach the end of the ferrule. Is this the case?

Tobin

Is the

 

[IceBergSlim]

In 10 seconds you had no air from a lp hose?

Your post was hard to understand....

 

[deepstops]

In 10 seconds you had no air from a lp hose?

Your post was hard to understand....

As I read it, the failure occurred at 70' with 800 psi remaining and it drained his tank in 10 seconds.

This compares accurately with tests done by Curt Bowen from Advanced Diver magazine.

 

[49thdiver]

In 10 seconds you had no air from a lp hose?

Rushing air was my first indication of a problem, no air at my reg was the second.
Less than a minute before, I had about 900lb remaining so I am guessing how much actual air I had, but I think it's reasonable to think 800lb. Realizing I had no air, (hose/reg not connected to tank any longer, as I found out later)and reaching for my octo, while feeling my high pressure line go limp as the noise of rushing air subsided was at the most 10 seconds. The barb is almost a 1/4 inch hole at 150lb +/- PSI It apparently does not take long. A high pressure hose by comparsion is a pinhole size orifice.

Sorry it was not clear.

 

[deepstops]

These tests were done with a full AL 80:

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 80ÃÔ 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 atmÃÔ / 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 atmÃÔ / 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.

 

[49thdiver]

Hard to tell from the pics, but it looks like the hose did not reach the end of the ferrule. Is this the case?

Tobin

I have since removed the "swage" and put it back on for the photo, so it is not 100% back where it was, but a good observation. My best guess is that the hose was not fully inserted in the "swage" as the hose does not appear full crimped to the same depth as the fitting, the pictures I have in situ and before removing the "swage" do not clearly indicate. but you can see about 1/8th inch space perhaps more, considering the barb is almost an inch long, perhaps it is in spec ?


Thanks

 

[Scared Silly]

As the tests show LP hose failures are way worse than a HP hose. Most people think the opposite. Pressure is only one factor. 49th did you try and kink the hose? I have always wondered how practical it would be.

 

[49thdiver]

49th did you try and kink the hose? I have always wondered how practical it would be.

I think a free flow reg or damaged hose at the reg end could be slowed down by kinking the hose (good idea) but in this case the hose came free from the fist stage, ie no hose to kink.