Buddies and I were having lunch at Scampis a couple blocks over after a dive, when we heard a thump. After finishing and driving by PCDC, we saw all sorts of emergency vehicles, and this:
It appears a bank tank blew and slammed a hole in the wall and a couple in the roof. Dive Locker said no one was hurt, so thats good.
zaberman1
June 13th, 2009, 09:28 PM
Buddies and I were having lunch at Scampis a couple blocks over after a dive, when we heard a thump. After finishing and driving by PCDC, we saw all sorts of emergency vehicles, and this:
It appears a bank tank blew and slammed a hole in the wall and a couple in the roof. Dive Locker said no one was hurt, so thats good.
Holy Crap John!
I'll call you when I get to tally, probably in 3 weeks...we can do efr than?
MRXRAY
June 13th, 2009, 09:34 PM
This was at Panama City Dive Locker?
LIVES4SHARKS
June 13th, 2009, 09:39 PM
Since I fill at my LDS, I will be interested to learn the facts about what happened. We take filling very seriously and it is a dangerous thing to do. I am glad no one was injured or killed.
Carolyn:shark2:
Fish Food
June 13th, 2009, 09:41 PM
This was at Panama City Dive Locker?
Looks like the Panama City Dive Center.
Glad everyone was alright. Was in there just today getting fills. Bet the it came as quite a surpirse to the adjoining wind surf shop it ripped through.
The parts of an exploded AL80 are mounted on the wall at my LDS to show everyone what can happen. Pretty scary stuff.......
SuPrBuGmAn
June 13th, 2009, 10:42 PM
Damn!!! :shocked2:
PatMyGreen
June 13th, 2009, 10:45 PM
A loud thump!? We heard it at the Bay Point Marina and were pretty sure people died it was so loud! There is alot of question as to why the steel flask blew given that the burst disk was intact.... I'm just happy Joe, Mike and everyone else were fine. Google Earth puts the distance from their shop to my boat at 1.4 miles, and it was scary loud.
MRXRAY
June 13th, 2009, 10:48 PM
Amen to that!
A loud thump!? We heard it at the Bay Point Marina and were pretty sure people died it was so loud! Everyone is fine and grateful. There is alot of question as to why the steel flask blew given that the burst disk was intact.... I'm just happy Joe, Mike and everyone else were fine. Google Earth puts the distance from their shop to my boat at 1.4 miles, and it was scary loud.
Tom Smedley
June 14th, 2009, 01:43 AM
It wasn't just one tank there were several and it completely destroyed their bank and part of tghe building. One cylinder landed in the rinse tank with the end blown off. Another was completely split open. Rest of the bank is scattered about and the front window is out but the retail part seems unscathed. thank God no one was hurt. We left the store ten minutes before it happened and heard the noise at the boats.
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LIVES4SHARKS
June 14th, 2009, 01:51 AM
Wow, I have heard plenty of stories of the AL 80's blowing, but your bank tanks? It's a very scary thought, especially when I look at where I fill in comparison to the banks.
Carolyn:shark2:
DA Aquamaster
June 14th, 2009, 07:23 AM
If a tank is "permanantly" installed and not readily transportable (ie: cannot be used in interstate commerce), the DOT regs for hydrostatic testing do not apply. Consequently, there are a lot of tanks out there in air banks that are seldom if ever hydro tested. I'd be interested in knowing the inspection history of the tank that failed and started the chain of events.
The good news with a steel tank rupture is it is usually just that - a rupture where the tank normally splits open rather than fragments. You get lots of suddenly expanding gas that can cause extensive damage but you get little or no fragmentation of the tank which normally occurs with an aluminum tank.
jviehe
June 14th, 2009, 08:23 AM
A loud thump!? We heard it at the Bay Point Marina and were pretty sure people died it was so loud! There is alot of question as to why the steel flask blew given that the burst disk was intact.... I'm just happy Joe, Mike and everyone else were fine. Google Earth puts the distance from their shop to my boat at 1.4 miles, and it was scary loud.
Just realized theres no such think as a loud thump. A thump is a feeling. But yeah, we felt the restauraunt shake. Pretty nuts. Imagine being in the shop. Tanks always scare me.
jviehe
June 14th, 2009, 08:24 AM
This was at Panama City Dive Locker?
Panama City Dive Center. Dive Locker is a different shop.
MRXRAY
June 14th, 2009, 08:48 AM
I usually go to the Dive Locker. Is PCDC on the same road, but closer to the water?
fppf
June 14th, 2009, 08:51 AM
That is not true, any cylinder stamped with DOT is always required to be within hydro test when it is filled no matter what the use. Just because its tucked away in the corner forever does not exempt it.
In truth, hydro test requirements are every 5 years for cylinders used in a bank application. Unlike many cylinders that qualify for the star exemption and only need to be tested every 10 years. Bank cylinders do not qualify for star because they are not removed from the bank when they are filled.
Only cylinders that are not hydroed are some ASME type tanks, which this could have been. The news article quotes a 16 foot tank. Unless the tank was a 5K rated or higher tank I would not believe for a second it has not been overfilled more than a few times in its life time.
Rick Murchison
June 14th, 2009, 08:57 AM
Right after we left the Panama City Dive Center shop yesterday afternoon (about 1530 CDT) a storage bottle blew. It ruptured another storage bottle so it ended up being a two bottle explosion.
One injury but not life threatening - a pretty good gash on a leg.
Pretty much blew the back end of the building off and damaged some other nearby buildings.
We are very lucky on this one!
Other shops in the area are filling and the boats are running...
I'll post more details when I have them.
Rick
openmindOW
June 14th, 2009, 09:05 AM
Wow. Thank you for this post.
Dadvocate
June 14th, 2009, 09:16 AM
Hey, Rick!
I'm glad you are okay and that no one else was seriously hurt. It is pretty remarkable everyone escaped major injuries.
Cheers!
Rick Murchison
June 14th, 2009, 09:35 AM
Threads merged & moved here
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SuPrBuGmAn
June 14th, 2009, 09:49 AM
I usually go to the Dive Locker. Is PCDC on the same road, but closer to the water?
Dive Locker is closer to Hwy98 and PCDC is on the end of the same road, but beachside. There is another diveshop in between the two(Divers Den). I typically use Dive Locker as well, when I'm diving out of the area.
DA Aquamaster
June 14th, 2009, 11:40 AM
That is not true, any cylinder stamped with DOT is always required to be within hydro test when it is filled no matter what the use. Just because its tucked away in the corner forever does not exempt it.We are not in complete disagreement, but you are being a bit too broad in your application of testing requirements. Generally speaking a "K" bottle is going to be considered portable regardless of where it is located by most DOT inspectors, so they tned to get requalified per DOT regs. A surplus submarine ballast tank is normally not portable and would not be testable by most facilities, so the odds of it ever being tested are slim and none.
From a strictly legal perspective it is simply a matter of jurisdiction. The DOT, formerly the Interstate Commerce Commission (ICC), only has jurisdiction over tanks that are used, or in some interpretations, could potentially be used, in interstate commerce. That is a distinctly different issue than whether periodic hydro testing is a good idea. So if the tank is not portable or is built in to the structure in such a way as to not be readily removeable from the building, the DOT regs are not going to be applicable. Consequently, they can technically be filled even without a current requalification stamp.
Also, due to the very small wall stress involved, tanks below a certain diameter and lenght do not require a hydro at all even if DOT stamped.
The grey area becomes user owned scuba and welding tanks that are not used in interstate commerce - but are portable and could eventually cross a state line or be used in commerce. DOT inspectors tend to assume the latter.
Local state, county and city regulations however may require compliance with the DOT regs or similar rules as a matter of local, not federal, jurisdiction.
You can adopt a holier than thou attitude about tank testing and look at it as a very black and white issue, but the DOT regs still won't apply in all cases.
Tom Smedley
June 14th, 2009, 12:50 PM
Mike and Jerry asked me to post this statement:
We would like to let everyone know everything except the storage system is fine and would like to thank everyone for their concern, prayers, and thoughts. We would also like to express our thanks to the other two local shops, Divers Den and Dive Locker, for their support during this interesting incident.
This message is sent from the Island Diver on the way to a great Panama City dive site.
mike_s
June 15th, 2009, 09:38 AM
First off I'm glad no one was seriously injured.
The News Herald has a brief write up:
Tank explosion takes out wall at dive shop - The News Herald (http://www.newsherald.com/news/shop-75008-beach-takes.html)
That's the same news story that someone emailed me. I'm going to post the text of it in case the newspaper takes it down off their site after a few weeks like some of them do.
Tank explosion takes out wall at dive shop
3
June 13, 2009 06:33:00 PM
By S. BRADY CALHOUN / News Herald Writer
PANAMA CITY BEACH A 16-foot compressed air tank exploded Saturday afternoon, knocking holes in the roof and east wall of Panama City Dive and Ski Center on Thomas Drive.
The explosion happened shortly before 4 p.m., officials said, and no one was hurt in the incident.
The large tank is used to fill other dive tanks, said Chief David Morrison, of the Bay County Fire Department. When the tank exploded, it sent other tanks shooting out of the building. Both Morrison and Jerry McLendon, a co-owner of the business, said they did not know why the tank exploded.
"It wasn't overfilled," McLendon said. "It had the proper amount of pressure in it."
The news article quotes a 16 foot tank. Unless the tank was a 5K rated or higher tank I would not believe for a second it has not been overfilled more than a few times in its life time.
I have no clue if it was overfilled. (the article says it wasn't).
However, I had one of their employees filling my AL80 tanks once (several years ago) and I looked up to see the pressure in my tank and saw it rising towards 3800psi. I asked him "is that my tank? (pointing to the 3800psi gauge)" he went "oh crap, what do I need to do? I answered, "I suggest you let some air out of the tank back down to 3000psi", which he did. :shakehead: (I don't know if he still works there or not, but he hasn't been in the shop the past times I've been there).
mike_s
June 15th, 2009, 09:52 AM
got love how clueless the media can be... check out this other story
They listed it as an Oxygen tank at Emerald Coast Kiteboarding Dive Shop.
(since when do they sell kites there? (or is that in an adjourning shop around the corner?)
maybe it was an oxygen tank... but who the heck has a 16ft O2 tank? I'm thinking they just generalized that an air(gas) tank was an O2 tank....
wmbb.com - Oxygen Tank Explosion Tears Down Wall (http://www.panhandleparade.com/index.php/mbb/article/oxygen_tank_explosion_tears_down_wall/mbb7717163/)
Oxygen Tank Explosion Tears Down Wall
06/13/09 - 06:42 PM
Erin Hawley - ehawley@wmbb.com
Bay County, Fla:
A dive shop on Thomas Drive accidentally celebrated what the owner called an early July 4th.
Emerald Coast Kiteboarding Dive Shop had an entire wall and window blown out when a reserve oxygen tank exploded Saturday afternoon.
Reserve tanks hold huge amounts of oxygen and are used to fill up dive tanks.
The fire department said that these tanks are supposed to have a valve that tells you when the tank’s pressure is approaching a dangerous level. This tank’s valve malfunctioned and blew into the dive shop building. The owner and workers say they were terrified.
“We thought an airplane crashed into the building, huge concussion shockwave,” says Mike Rush, Emerald Coast Kiteboarding owner. “One guy got cut on his shin that was in the dive shop. It blew concrete all the way across the road. This big tank launched like a torpedo between that wall and tore the wall down.”
I usually go to the Dive Locker. Is PCDC on the same road, but closer to the water?
Yes, right at the Thomas Dr T where you turn left to go to St Andrews.
MRXRAY
June 15th, 2009, 10:49 AM
That's what is confusing about the photo. This picture must be taken from behind the shop looking West, but that is the side that has the Surf/Kite shop in it. The Dive Shop is at the other end of the building.
Am I not right here?
panama city diveenter - Google Maps (http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=panama+city+diveenter&sll=37.0625,-95.677068&sspn=175.042949,360&ie=UTF8&ll=30.139219,-85.750295&spn=0,359.998326&z=19&iwloc=B&layer=c&cbll=30.139276,-85.750363&panoid=wK_1keBEmMPVv9f-lUBVQA&cbp=12,218.08,,1,-2.84)
Its the east side of the building yes.
looking at it on Street view, you know, of all the times I've been in that building and even parted in front of that "east side" shop, I've never noticed it being there. (I guess because typically it's because when I've been there, it's been 6:30am half the time).
As for the hole in the back of the building on the east side, I'm no expert on how their building is laid out, but Gomez has taken me back to see their Nitrox system before and I think the PCDC shop "L's" around the other shop. If I remember right, part of their compressor/bank/nitrox system was around to the left when you went in the back. (someone correct me if I'm wrong as it's been a couple years since I've been back there...)
fisheyeview
June 15th, 2009, 02:00 PM
This happened a few years ago at Ocean Divers in Key Largo. From what I remember they had a tripple bank of submarine ballast tanks, and the banks at the shop had not been drained and inspected for a long time.
When the bank blew it took out a concrete block wall, and large chunks of the wall flew across the canal. There was a sailboat tied up across the canal that was damaged.
No one was hurt in this case that I can recall. Scarey stuff.
mike_s
June 15th, 2009, 02:17 PM
I doubt that most shops go to the effort to re-hydro their bank systems. It requires a lot of down time to disassemble, sent out for hydro, re-clean (as required), and re-assemble and fix any leaks in fittings caused by all of this.
fisheyeview
June 15th, 2009, 03:09 PM
I would have to agree with you Mike. If I remember the case at Ocean Divers they at lease did yearly visuals on the banks, but the bottle that went could not be opened, so they let it go.
fppf
June 15th, 2009, 06:13 PM
I totally disagree, shops don't get there banks hydro because of money or there lazy.
All you need to do is take 1 bottle out of service at a time and send it out. If you have 10 bottles in your bank, that's only one every 6 months. If you can't afford to loose one bottle of capacity at a time, buy one spare bottle for every 5 and keep rotating.
There are easy ways to do this stuff, its not hard, and its not rocket science.
kgault
June 15th, 2009, 07:16 PM
I totally disagree, shops don't get there banks hydro because of money or there lazy.
All you need to do is take 1 bottle out of service at a time and send it out. If you have 10 bottles in your bank, that's only one every 6 months. If you can't afford to loose one bottle of capacity at a time, buy one spare bottle for every 5 and keep rotating.
There are easy ways to do this stuff, its not hard, and its not rocket science.
Have you ever tried to remove a single submarine ballast tank style bottle from a rack? These are the type of storage bottles that are the subject of this thread.
The Navy has this style of storage bottle inspected in place. I know of only 1 dive shop that has performed adequate inspection on this style of tank (to satisfy a government inspector) and it was done without moving the bottles.
Keith
fppf
June 15th, 2009, 07:24 PM
Yes, I know exactly the type of cylinder that was in use, and I don't agree in using them because dive shops do not ever have them inspected. Most inspection techniques for these cylinders are very costly because yes they need to be done in place. And yes, when you only have one huge cylinder you loose total use.
However, the majority of shops out there use a cascade of "T" cylinders, or others of that size with higher working pressures. Which are easy and cheap to get tested. They are also modular so you don't loose your whole bank.
jviehe
June 16th, 2009, 08:15 AM
Well gee, do we want to save a little time and money, or get sued when someone gets hurt and lose the shop? If you are going to own a dive shop you better be prepared to run it right. And that means making sure your tanks dont explode. It seems we have too many casually run dive shops out there.
Personally, when I worked at a dive shop, I was scared everytime I had to fill a tank, standing right over its questionably inspected metal, with no protection, turning on some old compressor, connected to never maintained hoses and such.
fisheyeview
June 16th, 2009, 09:02 AM
Have you ever seen a whip line go? It happened in a shop I was working in. Luckily no one was hurt, but it sliced through the wall like a hot knife through butter.
mike_s
June 16th, 2009, 11:14 AM
well it didn't take long for CDNN to plagiarize the story and put an exact copy of it up on their website and change the authors name to someone from CDNN. :shakehead:
kgault
June 16th, 2009, 11:32 AM
Well gee, do we want to save a little time and money, or get sued when someone gets hurt and lose the shop? If you are going to own a dive shop you better be prepared to run it right. And that means making sure your tanks dont explode. It seems we have too many casually run dive shops out there.
Personally, when I worked at a dive shop, I was scared everytime I had to fill a tank, standing right over its questionably inspected metal, with no protection, turning on some old compressor, connected to never maintained hoses and such.
When divers start putting their money where their mouth is and only get fills from shops that perform all required maintenance, then these shops will have an incentive to perform the maintenance, as well as be able to afford to perform this same maintenance :)
The shops that are still in business are those that have performed the cost benefit analysis and choose the maintenance to perform based upon what they can afford to do (or less) while remaining profitable. This is similar to the trade off the auto industry evaluates for safety recalls vs lawsuits.
We as divers set the level of safety in the Industry that supports our hobby/sport.
The list of dive shops that perform all required maintenance and meet OSHA, etc guidelines will be very short.
Keith
Doc Harry
June 16th, 2009, 12:38 PM
Have you ever seen a whip line go? It happened in a shop I was working in. Luckily no one was hurt, but it sliced through the wall like a hot knife through butter.
Why do you think it's called a whip?
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mike_s
June 16th, 2009, 12:47 PM
When divers start putting their money where their mouth is and only get fills from shops that perform all required maintenance, then these shops will have an incentive to perform the maintenance, as well as be able to afford to perform this same maintenance :)
The shops that are still in business are those that have performed the cost benefit analysis and choose the maintenance to perform based upon what they can afford to do (or less) while remaining profitable. This is similar to the trade off the auto industry evaluates for safety recalls vs lawsuits.
We as divers set the level of safety in the Industry that supports our hobby/sport.
The list of dive shops that perform all required maintenance and meet OSHA, etc guidelines will be very short.
Keith
I wouldn't get your hopes up on seeing this happen anytime soon.
for most dive shops, air fills are merely a necessary evil that is a "loss leader" to get people in the shop for other sales.
DA Aquamaster
June 16th, 2009, 01:01 PM
Have you ever tried to remove a single submarine ballast tank style bottle from a rack? These are the type of storage bottles that are the subject of this thread.
The Navy has this style of storage bottle inspected in place.They Navy also tends to treat them as a limited service life item and replaces them when they age out as part of a major refit. That does not prevent them from showing up on the surplus market, or eventually having older tanks that were not replaced in service due to the decommissioning of a vessel eventually showing up after the scrap yard removes them.
rox@ucf11
June 16th, 2009, 01:47 PM
I was down the street with John at Scampys and heard and felt the explosion as well, sounded like some loud thunder at the time but it rattled the building which we thought was strange so we were wondering what happened
jviehe
June 16th, 2009, 03:25 PM
When divers start putting their money where their mouth is and only get fills from shops that perform all required maintenance, then these shops will have an incentive to perform the maintenance, as well as be able to afford to perform this same maintenance :)
The shops that are still in business are those that have performed the cost benefit analysis and choose the maintenance to perform based upon what they can afford to do (or less) while remaining profitable. This is similar to the trade off the auto industry evaluates for safety recalls vs lawsuits.
We as divers set the level of safety in the Industry that supports our hobby/sport.
The list of dive shops that perform all required maintenance and meet OSHA, etc guidelines will be very short.
Keith
Well, the main problem is we dont know what service is required. For sure, new divers dont. Id be interested in hearing from some dive shop owners as to the costs and problems associated with the safety aspect if running a dive shop.
PhilEllis
June 16th, 2009, 05:11 PM
Well, the main problem is we dont know what service is required. For sure, new divers dont. Id be interested in hearing from some dive shop owners as to the costs and problems associated with the safety aspect if running a dive shop.
It is both wonderful and amazing that casualties at PCDC were limited to cuts. I am so glad that Mike and Jerry and the whole crew avoided any more serious injury. Also quite fortunate that no customers were injured.
To be honest, operating our air system causes me more restless nights than any other part of our business. The power of compressed air is gigantic, and I worry a lot about the impact of fittings coming loose, hoses flying, and bottles failing. I worry about every cylinder we fill.....was the inspection done well enough? Was the hydro done properly? Is there a problem with the valve? Lots of potential issues. While the statistical probability of such failures is extremely small, they still happen.
I have passed on opportunities to install larger bulk storage devices. I have had opportunities to purchase them very cheap....in fact, almost as low as the scrap metal value. Instead, we use HC6000 Taylor Wharton bottles in a somewhat permanent installation. We clean and inspect them each winter, but we are coming up on the first hydro this winter. This is considerable work, but it needs to be done.
Phil Ellis
www.divesports.com
FredT
June 16th, 2009, 07:45 PM
From the limited information that can be gleaned from the single picture showing the tanks in this thread those appear to be transport skid bottles, not Submarine bottles. Sub tanks are curved, skid bottles aren't. Different rules apply to each of those. I'm willing to let the inevitable PCB fire department investigation run a while before I make any judgment at all on this incident. Something caused the failure, so let's allow those with the parts in their hands to make an informed call as to what it was.
I may have an opinion, but that is all it can be until I get a chance to see the leftovers. Tom and Rick both have the experience to make a well educated guess, and they were nearby. let's wait until we at least hear more details from them before wildly speculating as to cause or accusing anybody.
jviehe
June 17th, 2009, 10:13 AM
It is both wonderful and amazing that casualties at PCDC were limited to cuts. I am so glad that Mike and Jerry and the whole crew avoided any more serious injury. Also quite fortunate that no customers were injured.
To be honest, operating our air system causes me more restless nights than any other part of our business. The power of compressed air is gigantic, and I worry a lot about the impact of fittings coming loose, hoses flying, and bottles failing. I worry about every cylinder we fill.....was the inspection done well enough? Was the hydro done properly? Is there a problem with the valve? Lots of potential issues. While the statistical probability of such failures is extremely small, they still happen.
I have passed on opportunities to install larger bulk storage devices. I have had opportunities to purchase them very cheap....in fact, almost as low as the scrap metal value. Instead, we use HC6000 Taylor Wharton bottles in a somewhat permanent installation. We clean and inspect them each winter, but we are coming up on the first hydro this winter. This is considerable work, but it needs to be done.
Phil Ellis
Discount Scuba Gear at DiveSports.com - Buy Scuba Diving Equipment & Snorkeling Equipment (http://www.divesports.com)
Yes, I agree, having worked at a fill station, done gas mixing, and taken the VCI course, the more I learn, the scarier it gets. What about actually filling bottles? Is this done behind a blast wall, is this neccesary, and whats the cost of such safety?
PhilEllis
June 17th, 2009, 11:05 AM
Yes, I agree, having worked at a fill station, done gas mixing, and taken the VCI course, the more I learn, the scarier it gets. What about actually filling bottles? Is this done behind a blast wall, is this neccesary, and whats the cost of such safety?
We do not use a blast containment system. I think that is the case with well over 98% of all scuba stores. I have looked into the cost of a containment system. They are both expensive and add a considerable amount of labor to the cost of air delivery. Cylinder fill practices in a scuba store bring the bulk of all fills into a very short period of time. While the fill station sits for hours and hours and hours without a fill, we are then often presented with the need to fill 40-50 cylinders in a very short period of time. The containment systems that I have reviewed REALLY slow the process, and economical ones don't provide for filling more than a couple of cylinders at a time. I think the safest thing to do is to run a solid cylinder inspection program, to question cylinders presented with inspections done by "unknown" sources, and to err on the side of caution by not bringing ANY questionable cylinders into the fill operation.
Many people have questioned the "loss leader" aspects of filling scuba tanks. That is partly correct. Cylinders used for training classes are filled and they represent only a cost. There is not specific revenue attached to those cylinders. In our store, where we fill only slightly more than 100 revenue-producing cylinders per month, the monthly revenue from all other cylinders barely covers the monthly expenses from running the compressor, testing the air, and maintaining the fill system. That does not even factor in the capital investment for the fill station.
It is a difficult situation for most low to medium volume scuba fill stations. Money spent must be recovered. We simply have to use the best possible practices and use the best available caution.
Phil Ellis
www.divesports.com
Rick Murchison
June 17th, 2009, 12:11 PM
as for the tank that blew, it was a 16' long tank I think.Looked longer than that to me... my guess was 24' - but I didn't measure.
Rick
Hallmac
June 17th, 2009, 12:57 PM
as for the tank that blew, it was a 16' long tank I think.
can you even get something like that hydro'd? (I bet not easily).
If they are like these, they are given a visual and then hammer tested. I have never seen a facility that could hydro them. We have 4 in our air bank.
Tom Smedley
June 17th, 2009, 01:01 PM
It is almost impossible to hydro one of the large cylinders. The test that is probably most recommended is a hammer test. The tank is emptied and struck with an appropriate size hammer. If the metal rings like a bell it is most likely healthy but if there is a dull thud it is not. Do a Google search on compressed gas hammer test.
Just the cost of transporting a large cylinder to a hydro facility would be enormous - that is if you could find a facility that would be able to do the test. I don't think our local fire-extinguisher folks would be able to.
Let's hope for most of the dive shops in the world that OSHA does not get involved with this incident but I fear they will. I've worked directly for the US government since 1967 and the fact that they screw up anything they touch hasn't changed.
Leadking
June 17th, 2009, 01:10 PM
2) A hammer test consists of tapping a cylinder a light blow with a suitably sized hammer. A cylinder emptied of liquid content, with a clean internal surface, standing free, will have a clear ring. Cylinders with internal corrosion with give a duller ring dependent upon the amount of corrosion and accumulation of foreign material. Such cylinders shall be investigated. The hammer test is very sensitive and is an easy, quick, and convenient test that can be made without removing the valve before each charging. It is an invaluable indicator of internal corrosion.
mike_s
June 17th, 2009, 01:56 PM
the question also lies in what was the cylinder that ruptured rated at and what was it filled to? (I guess all this will come out in the investigation).
mkutyna
June 17th, 2009, 02:04 PM
I'm pretty sure that tumbling is out of the question for those large bank bottles as well yes? Is a vis is used to determine if it should be taken out of service or not? Sure, you can open the bottle up and look inside all you want but I doubt you'd be able to do anything about any minor corrosion if you happen to see any.
Hallmac
June 17th, 2009, 03:11 PM
True about tumbling, it is not cost effective. We have used a whip once. The key is preventing as much moisture from entering as possible. Testing often, and crying when you have to take them out of service...
jviehe
June 17th, 2009, 03:13 PM
I'm pretty sure that tumbling is out of the question for those large bank bottles as well yes? Is a vis is used to determine if it should be taken out of service or not? Sure, you can open the bottle up and look inside all you want but I doubt you'd be able to do anything about any minor corrosion if you happen to see any.
Good point. How do you ensure nitrox banks are 02 clean?
mike_s
June 17th, 2009, 03:32 PM
Good point. How do you ensure nitrox banks are 02 clean?
for the above store, PCDC, they don't have o2 clean air.
they blend, (or whatever) before they get to the banked storage. So they are never introducing "pure o2" into their storage tanks. (from what Gomez told me a few years ago when he was showing me their system. someone correct me if anything has changed in the last 2 years.).
FredT
June 17th, 2009, 06:56 PM
I'm pretty sure that tumbling is out of the question for those large bank bottles as well yes? Is a vis is used to determine if it should be taken out of service or not? Sure, you can open the bottle up and look inside all you want but I doubt you'd be able to do anything about any minor corrosion if you happen to see any.
ANY long straight bottle can be tumbled with a little "think outside the box" ingenuity. Two house trailer axles (easily rented) a pair of railroad ties and car or golf cart can be combined to make a functional tumbler for big tanks. Getting the media in and out is the hard part. ;)
Cost effective, probably not, as by the time it fails the hammer test you may have a scrap bottle anyway. An agitated acid rinse could be done for a couple hundred $ of materials and tools though. Both would require a crane of some sort to dismount and drain the bottles though.
Leadking
June 17th, 2009, 07:24 PM
unusual construction compared to scuba tanks. Note the top rim and the welded sidewall
Got pictures fowarded to me today!
Those 2 photos don't show anything obvious. The seam split adjacent to the weld at the edge of the heat effected zone, just like it's supposed to. The end cap appears to have a weld metal failure, but to determine if this was a primary or secondary failure will take a lot more investigation. That will take a few days of stereo microscope work at least to nail down the exact crack initiation point(s), then it starts to get interesting.
jviehe
June 18th, 2009, 07:43 AM
Of course, these tanks are sitting outside in salt air 24/7. That cant be good.
Leadking
June 18th, 2009, 08:46 AM
Those 2 photos don't show anything obvious. The seam split adjacent to the weld at the edge of the heat effected zone, just like it's supposed to. The end cap appears to have a weld metal failure, but to determine if this was a primary or secondary failure will take a lot more investigation. That will take a few days of stereo microscope work at least to nail down the exact crack initiation point(s), then it starts to get interesting.
I am not saying the construction had anything to do with failure, just that compared to scuba cylinders, they're interesting.
FredT
June 18th, 2009, 09:35 AM
Agreed. Be aware that there are DOT specs for welded pressure vessels too, as well as the ASME specs. If I remember correctly the diesel submarine bottles were seamless with hot spun ends.
The photos do prove however that they were NOT the known problematic torpedo bottles.
TheMadDane
June 18th, 2009, 11:19 AM
Is it just my metallurgical ignorance or does that bottle look pitted and corroded on the inside?
DA Aquamaster
June 18th, 2009, 01:30 PM
Is it just my metallurgical ignorance or does that bottle look pitted and corroded on the inside?There are pretty impressive pits caused by corrosion. Of course at what point a pit becomes a reason to fail the tank depends on the tank and the specifications set forth by the manufacturer. If the tank is over engineered and has a lot more wall thickness than it needs, a larger pit can be tolerated.
Scuba tanks are designed to be easily portable and that portability creates a design constraint for the wall thickness and total weight of the tank. That is not as much of an issue for a tank that is not intended to be portable and where weight is not as significant a factor. In that case, if a 1/4" wall thickness is required, you could have 1/2" walls and a tank that weighs twice as much and not really have a problem. In the latter case, a pit could be larger and deeper before it begins to create a stress riser that is significant from a safety perspective.
But with the tank in question the corrosion and pitting visible in the picture is so expansive that it would have made me nervous.
CompuDude
June 18th, 2009, 06:55 PM
True about tumbling, it is not cost effective. We have used a whip once. The key is preventing as much moisture from entering as possible. Testing often, and crying when you have to take them out of service...
There are pretty impressive pits caused by corrosion. Of course at what point a pit becomes a reason to fail the tank depends on the tank and the specifications set forth by the manufacturer. If the tank is over engineered and has a lot more wall thickness than it needs, a larger pit can be tolerated.
Scuba tanks are designed to be easily portable and that portability creates a design constraint for the wall thickness and total weight of the tank. That is not as much of an issue for a tank that is not intended to be portable and where weight is not as significant a factor. In that case, if a 1/4" wall thickness is required, you could have 1/2" walls and a tank that weighs twice as much and not really have a problem. In the latter case, a pit could be larger and deeper before it begins to create a stress riser that is significant from a safety perspective.
But with the tank in question the corrosion and pitting visible in the picture is so expansive that it would have made me nervous.
I had the same thought when I looked at the photos (posted on another forum). Those look to be some pretty MAJOR pits and corrosion. Maybe they're not the reason for the failure, maybe they are, but from the standpoint of my PSI training, there's no way in heck that tank would have passed any sort of visual inspection.
Scuba-grade air from properly-maintained compressor filtration stacks should be bone dry, right? Looks like a fairly large amount of moisture has been getting inside that bottle to cause that much corrosion.
I'm curious about the opinion of others with more experience on the subject.
DA Aquamaster
June 19th, 2009, 09:04 AM
The picture also shows only a limited area of the tank - I'd love to see the pitting in areas near where the failure started.
PhilEllis
June 19th, 2009, 09:45 AM
Also, there should be no such thing as non revenue fills. The cost of fills for classes, instructors and dive masters should be taken into account in the cost of the per student classes.
Oh, that is worth a thread all by itself!
Phil Ellis
www.divesports.com
Rick Murchison
June 19th, 2009, 11:27 AM
Oh, that is worth a thread all by itself!
Phil Ellis
www.divesports.com (http://www.divesports.com)
So shall ye ask, so shall it be done... :)
Discussion on the profitability of fill stations moved here (http://www.scubaboard.com/forums/compressors-boosters-nitrox-trimix-blending-systems/290350-thars-money-them-thar-air-fills.html).
Rick
Doc Harry
June 19th, 2009, 06:52 PM
2) A hammer test consists of tapping a cylinder a light blow with a suitably sized hammer. A cylinder emptied of liquid content, with a clean internal surface, standing free, will have a clear ring. Cylinders with internal corrosion with give a duller ring dependent upon the amount of corrosion and accumulation of foreign material. Such cylinders shall be investigated. The hammer test is very sensitive and is an easy, quick, and convenient test that can be made without removing the valve before each charging. It is an invaluable indicator of internal corrosion.
BTW, hammer test applies only to steel cylinders
pcbdownunder
June 23rd, 2009, 10:14 AM
I was by the Panama City Dive Center yesterday (June22) and they are again filling air tanks, but don't have their Nitrox up and running. Mike and Jerry said they apologize for any inconvenience this may have caused for their loyal diving friends.
Rick Christ
June 27th, 2009, 07:01 PM
Panama City Dive Center blows out the wall.
Tank explosion takes out wall at dive shop - The News Herald (http://www.newsherald.com/news/shop-75008-beach-takes.html)
June 13, 2009
Rick Christ
June 27th, 2009, 07:05 PM
more photos
I couldn't get them all on one post
mike_s
June 28th, 2009, 12:31 AM
wow..... those are some freakin' rusty cylinder banks.....
if they are that rusty visually, why the heck would you have them in service with high pressure air? ???????
is this a hydro date of 7 60 (as in 1960?) on this cylinder?
looks that way, I think the one above it says 6-56??
Look at the first pic in the set of four, it does not look like a wrench has touched those fittings and valves in a really long time. Never mind the fact that these blew up, but all the crap inside, you want to breath that?
mike_s
June 28th, 2009, 01:38 AM
yeah I wondered if that above stamp was from 1956. nothing wrong with old cylinders if they are properly maintained.... but that is key. that's a pretty rusty cylinder to be using for anything, much less for commercial use.
as for the rust, PCDC sits about a block off the beach. so salt spray is going to affect anything...
I'm no professional expert on cylinder bank systems, but this setup doesn't look all that great of a maintained system. (someone correct me if I'm wrong).
Rick Christ
June 28th, 2009, 06:47 PM
Never mind the fact that these blew up, but all the crap inside, you want to breath that?
That is the settlement of the sand that fell back down on the cylinder from the ground under the tanks. In addition, concrete chucks from the wall are left on the ruptured tank.
Rick Christ
June 28th, 2009, 07:05 PM
that's a pretty rusty cylinder to be using for anything, much less for commercial use.
as for the rust, PCDC sits about a block off the beach. so salt spray is going to affect anything...
I'm no professional expert on cylinder bank systems, but this setup doesn't look all that great of a maintained system. (someone correct me if I'm wrong).
Picture #38 is extreme/severe line corrosion
fppf
June 28th, 2009, 10:34 PM
Um, yeah no duh the sand is from blast derby, I'm talking about all the rust and scale on the inside of the tank. If you did a visual on a steel scuba cylinder you would try to tumble it or fail it, but not put it back in service.
As for the salt spray, that should be taken into account during the install and maintenance routines. The steel must be protected, maybe a small shed structure, paint, wash downs, or all of the above.
TheMadDane
June 29th, 2009, 02:39 AM
How about just sand blasting and painting? These tanks look like they could have gone up at any time....
:bash: :whack: :shocked: Oh wait... They DID! :bash: :whack: :shocked:
deepseainit
June 29th, 2009, 07:36 PM
There has been testing to prove that hydroing steel cyl. is not cost effective with the movement and drying of the flasks. So with that being said you should do undestructive testing (udt) and shear wave testing on these flasks every six years. These test for metel thickness (type of flask you have should have a min. wall thickness), stress cracks in the flask and welds. Also you can have these tests done in place. You should also do anual visual inspections of the exterior ( take pics) so you can compare each year. Im not sure what kind of these bottles are but usally have a max alowable pressure like 5000 psi (mawp 5000 psi @ __ F stamped on neck), so you should have a relief valve set @ 4500 psi.(10% under). The relief valve also needs to be able to flow enough air for your set up and have no stop valves between flasks and relief valve. Relief valves need to be tested at least every 3 years. High pressure rubber hose needs to be inspected every year for cracking, cuts, and any signs that its pulling out of the fitting. replace these hose's no matter what every 12 years.
Please dont take my word for this info. Do a research for navy flask inspection, and you will find a ton of info you can implement into your maint. schedual. One good one I found was (tm-cheng 05-010-sca rev b) lots of good info. Good luck to all you dive shops out there to make good air safely....
