Tank explosion kills one - Cozumel
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Ken Kurtis
Contributor
Just to be clear, I also don't think it's right/legal for a shop to fail a tank on a VIP (Visual Inspection Program) and destroy/disable it. I'm talking about when it's hydroed or if an eddy test is done and cracks are detected (which could be done while a tank still has a current hydro).
If a tank fails a visual inspection, the shop should recommend a tumble and whatever it is that needs to be done to make the tank pass the VIP. the customer is certaoinly free to decline to do that. And now comes the tricky part.
When you do a VIP, the FIRST thing you're supposed to do is remove ALL stickers from the tank. This does two things. One is that it allows you to check for corrosion, bubbling, defects, etc., that might have been hidden under the stickers. Two is that if the tank fails the VIP and the customer doesn't want to have it corrected/fixed, the tank no longer has a valid VIP sticker and - in theory - can't be filled (by a reputable shop).
The problem is that many shops (I don't think "most" applies) don't remove the old VIP sticker, let alone other stickers, when they do the inspection. So if the tank fails, the customer takes it, it still has a valid VIP (for whatever time is remaining), and goes somewhere else to have it filled. Because obviously, we're just trying to scam you out of a $50 tumble. THAT'S where we REALLY make all of our money. besides, it's only your life we're talking about . . . (NOTE: Sarcasm in green bold type.)
- Ken
Scared Silly
Contributor
FWIW a few years ago in Costa Rica I checked the requal stamps on the cylinders and found one to be in hydro but it was an Al6351 cylinder. Now in the USA it would need a VE stamp but had none. I politely asked that the cylinder not be used during our stay. Request granted. That evening I talked with several of the shop folks and gave them more details and contacted the owners when I returned.
I do the same for all of my trips. The easiest way to get a general idea is when they are getting ready to load cylinders on to the boat. Start doing spot checks. When crew asks what you are up to tell them, then walk into the compressor bldg and ask to see the set up with logs. The more you ask the better everyone will be.
I do the same for all of my trips. The easiest way to get a general idea is when they are getting ready to load cylinders on to the boat. Start doing spot checks. When crew asks what you are up to tell them, then walk into the compressor bldg and ask to see the set up with logs. The more you ask the better everyone will be.
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harmonised
Registered
How is it possible for a tank to explode? I thought they were like at least "1/2 thick metal...
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Crook your index finger, ok? That is approximately one square inch. Now imagine what 3,000 pounds (a small car) or more would be like there? It gets more complicated when you try to factor leverage, metal structure, fatigue, etc.
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flots am
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A new SCUBA cylinder with no flaws is extremely, unbelievably strong and has an over-pressure relief device (a burst disk). It's nearly impossible to explode one.
The problem is that some cylinders develop flaws due to mishandling, manufacturing defects or metal that turned out to be not-quite-strong-enough. These tanks develop cracks and flaws and are no longer as strong as required. Some tanks are also subject to stupid-human tricks like replacing the burst disk with a plug and overfilling.
Cracks and flaws are detected before they fail (explode) during hydrostatic testing, and with a special machine that analyzes the neck and threads, which is why a tank exploding in a shop that actually follows the rules is unbelievably unlikely.
The problem is when a shop or fill station doesn't follow the rules. The cracks aren't detected soon enough, or the bad alloy tanks aren't taken out of service, and you end up with what happened here.
If the tanks are properly inspected, handled, filled and serviced, an explosion is a freak occurrence, about as likely as having Superman show up for dinner.
flots.
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dumpsterDiver
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Just to be clear, I also don't think it's right/legal for a shop to fail a tank on a VIP (Visual Inspection Program) and destroy/disable it. I'm talking about when it's hydroed or if an eddy test is done and cracks are detected (which could be done while a tank still has a current hydro).
If a tank fails a visual inspection, the shop should recommend a tumble and whatever it is that needs to be done to make the tank pass the VIP. the customer is certaoinly free to decline to do that. And now comes the tricky part.
When you do a VIP, the FIRST thing you're supposed to do is remove ALL stickers from the tank. This does two things. One is that it allows you to check for corrosion, bubbling, defects, etc., that might have been hidden under the stickers. Two is that if the tank fails the VIP and the customer doesn't want to have it corrected/fixed, the tank no longer has a valid VIP sticker and - in theory - can't be filled (by a reputable shop).
The problem is that many shops (I don't think "most" applies) don't remove the old VIP sticker, let alone other stickers, when they do the inspection. So if the tank fails, the customer takes it, it still has a valid VIP (for whatever time is remaining), and goes somewhere else to have it filled. Because obviously, we're just trying to scam you out of a $50 tumble. THAT'S where we REALLY make all of our money. besides, it's only your life we're talking about . . . (NOTE: Sarcasm in green bold type.)
- Ken
I didn't know that tumbling a tank restores its' structural integrity, will prevent a tank explosion from occurring during the remaining time period on an annual sticker and will save a person's life. So salt build up and corrosion strengthen burst discs and tumbling actually increase the strength of the materials..
widget
Contributor
Just to be clear, I also don't think it's right/legal for a shop to fail a tank on a VIP (Visual Inspection Program) and destroy/disable it. I'm talking about when it's hydroed or if an eddy test is done and cracks are detected (which could be done while a tank still has a current hydro).
If a tank fails a visual inspection, the shop should recommend a tumble and whatever it is that needs to be done to make the tank pass the VIP. the customer is certaoinly free to decline to do that. And now comes the tricky part.
When you do a VIP, the FIRST thing you're supposed to do is remove ALL stickers from the tank. This does two things. One is that it allows you to check for corrosion, bubbling, defects, etc., that might have been hidden under the stickers. Two is that if the tank fails the VIP and the customer doesn't want to have it corrected/fixed, the tank no longer has a valid VIP sticker and - in theory - can't be filled (by a reputable shop).
The problem is that many shops (I don't think "most" applies) don't remove the old VIP sticker, let alone other stickers, when they do the inspection. So if the tank fails, the customer takes it, it still has a valid VIP (for whatever time is remaining), and goes somewhere else to have it filled. Because obviously, we're just trying to scam you out of a $50 tumble. THAT'S where we REALLY make all of our money. besides, it's only your life we're talking about . . . (NOTE: Sarcasm in green bold type.)
- Ken
Yes, indeed, VIP Stickers are not legal here, the tank neck has to be physically stamped with the letters H (Hydro) or V (visual), the date of the test and the test stations unique ID.
No reputable shop will fill a tank without checking to see these stamping's are valid and in date.
No dive shop can test cylinders here, not even visual tests, all testing has to be done by Sanas (South African National Accreditation System) Approved test stations, and these stations are supplied with a unique logo stamp which is punched into the cylinder neck at every test, without the unique logo preceding the relevant information the tank would be deemed "untested" and would not be filled.
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