Are hydros really necessary?

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Injuries from tire and wheel explosions during... [Ann Emerg Med. 1991] - PubMed - NCBI

For the period of 1978 through 1987, there were 694 reported injuries from explosions during tire servicing; 143 of them were fatal, resulting mainly from truck tires. Because the three data sources used different methods for case finding and covered different time periods, the actual number of such injuries was probably greater. Head injuries accounted for 78% of the deaths and 24% of nonfatal injuries. The proportion of injuries occurring during tire inflation declined from 51% in 1978 to 33% in 1987 (P less than .05). Fatal injuries involving single-piece rim wheels increased during the 1980s as multipiece rim wheels were phased out by the trucking industry.

It's not that I don't understand that pressure vessels can be dangerous. I have a healthy respect for scuba tanks under pressure. I own a tire store and a scuba compressor. I consider the tires to be much more likely to kill me than the scuba tanks. The statistics bear that out. All the clamor about unrecertified tanks is overdone. You are in a lot more danger of dying from a car accident while carrying full, unhydroed, old, "dangerous alloy" aluminum tanks than you could ever be from the tanks themselves exploding either on their own or in the accident. When diving old, never hydroed, pre 87 aluminum tanks in Mexico I am much more concerned about debris in the tank closing off my air supply than I am the tank exploding on me. I've watched the someone go feet up and lose their air. Unless they are mistreated when full of O2 they just don't explode after the fill. And I'm talking about "Bad alloy" AL tanks not steels or newer aluminums. The score so far is about 20 failures in 50+ years and 30 or 40 MILLION cylinders. Almost if not all of them were being filled. If you are afraid of those odds you should not be diving, or driving. And those are the odds for the "Bad" 6351 tanks. If you want to talk about dangerous pressure vessels, tires are worse than all the rest put together, and nobody thinks about them.
 
A diving tank is a pressure vessel.
A propane tank is a pressure vessel.
A oxy acetylene tank are pressure vessels.
A boiler is a pressure vessel.

The regulations are for pressure vessels. The fact that we use one is why they have to be inspected.

I'm going to assume for your sake you're referring to regulations in America's Hat.
 
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Another bit from the CFR, if a cylinder becomes expired it can remain in use until empty but must be recertified before being refilled. So I have a full or partially full tank that has an expired hydo date, I can continue to have it at my house, drive it around in my car, boat whatever. If I am in the welding business and the cylinder is on the back of my business truck because I am still using it I can drive it around in commerce. The rule applies to all DOT containers not just scuba cylinders. That part right there blows the the must be maintained in hydro at all times no matter who, when or where out of the water.
 
I think its ridiculous that you all are parsing the CFRs in this way trying to determine if the USDOT has "jurisdiction".

You're kidding, right?! Jurisdiction is EVERYTHING when it comes to the scope and authority of law, even regulations!

---------- Post added October 18th, 2014 at 01:05 PM ----------

So I have a full or partially full tank that has an expired hydo date...

How can you sleep at night, Captain? You need to immediately empty those cylinders and remove, obliterate, or securely cover the DOT markings or you'll get thrown in the slammer!:no:
:wink:
 
Another bit from the CFR, if a cylinder becomes expired it can remain in use until empty but must be recertified before being refilled. So I have a full or partially full tank that has an expired hydo date, I can continue to have it at my house, drive it around in my car, boat whatever. If I am in the welding business and the cylinder is on the back of my business truck because I am still using it I can drive it around in commerce. The rule applies to all DOT containers not just scuba cylinders. That part right there blows the the must be maintained in hydro at all times no matter who, when or where out of the water.


Nothing Personal - but rules and regulations are made for the non knowledgeable so they don't have to do advanced theory in ????? for every thing they may encounter in their hobby or business life -----you can not regulate for stupid no matter how many times it has been tried. --- BUT SUR it's not empty yet so I kept there for 20 years - no idea why it went bang
 
Nothing Personal - but rules and regulations are made for the non knowledgeable so they don't have to do advanced theory in ????? for every thing they may encounter in their hobby or business life -----you can not regulate for stupid no matter how many times it has been tried. --- BUT SUR it's not empty yet so I kept there for 20 years - no idea why it went bang

If that were actually perceived to be a problem, regs could easily have required tank be removed from service and emptied upon hydro expiration or any time period thereafter, like one year.

It is not at all uncommon to find an old scuba tank that has been unused for many years that still has pressure.

Some of the conflict may be that most of these regs are written with safety being the primary concern, not profit.
 
Fundamentally, if you have to rely on someone else for tank fills, and that 'someone else' requires current hydros/visuals before they will fill your tanks, then hydros/visuals ARE required ! I'm amazed people devote so much time/energy debating DOT regs, etc when it's completely irrelevant in the real world!
 
Fundamentally, if you have to rely on someone else for tank fills, and that 'someone else' requires current hydros/visuals before they will fill your tanks, then hydros/visuals ARE required ! I'm amazed people devote so much time/energy debating DOT regs, etc when it's completely irrelevant in the real world!

The relevance is that it is much easier on THEM if THEY can make you believe it is a DOT requirement.:crafty:
 
Hydros are required for safety. There will be many who break the rules. If I find a dive shop or dive operation/boat that does this I will never use them again. Unless on a live a board out of the country I bring my own tanks. The rules were made for a reason. SAFETY!
 
Hydros are required for safety. There will be many who break the rules. If I find a dive shop or dive operation/boat that does this I will never use them again. Unless on a live a board out of the country I bring my own tanks. The rules were made for a reason. SAFETY!

Don't you have a minivan full of urchins to drive to soccer practice?
 
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