R
redacted
Guest
Rick Murchison:
Some comes from the guy with the whip, but some comes from individual users who slap their 1st onto a boat tank without blowing a little air thru the exposed valve.
VIP on AL cylinders = stupid $$$ game
- Thread starter Crazy Fingers
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Some comes from the guy with the whip, but some comes from individual users who slap their 1st onto a boat tank without blowing a little air thru the exposed valve.
reefraff:Over the years this argument resurrects and it always follows the same pattern: some cyber-diving sophist (usually an irascible combination of cheap, ignorant and curmudgeon) makes a ranting troll of a post accusing dive shop owners and their evil minions (the dread dive shop monkeys) of participating in an International Conspiracy to force them to have their tanks inspected/regulators serviced/teeth brushed. Sometimes the mope got his dope from the friend of a guy that knows someone, maybe it came from applying a special knowledge of numerology to the secret codes that are hidden in all CGA publications, occasionally it was revealed to him only after he started using a premium brand of tinfoil for his window shades, whatever.
I can't speak for dental hygienists, but those of us who actually work in a shop quickly learn that the inspection service protocols not only don't enrich us but also make diving safer - we see the insides of enough tanks and regulators to have the first-hand proof. Statistics about sustained load cracking are interesting but, for those of us who have pulled tanks from service because of neck cracks, they are mostly academic. The corrosion characteristics of aluminum are complex but anyone who has ever stuck a pick 1cm into a hydroxide pit knows that arguing whether or not aluminum corrodes is as much a semantics discussion as a scientific one.
I see enough of your gear to know that the once-per-year inspection protocol for cylinders and regulators is appropriate. Given the nature some of you ascribe to us DSM's, some will find it odd that I actually care about the divers that use my services and am concerned with their benefit as well as my own plums when I say that I hope that every diver is conscientious enough to see that it gets done. As Rick pointed out, however, there are some divers out there that simply won't believe. Though I find most of them tedious as well as peevishly tenditious, I don't feel any personal animus towards them so long as they get their cylinders filled elsewhere. Fortunately, there are solutions available for those concientious objectors who eschew the visual inspection protocols, which I am happy to help facilitate. For a small commission.
Good job, Reefraff!
Rick
CrazyFingers:[REAL SITUATION: Some cylinders made with the AL-6351 alloy exhibit sustained load cracking in the neck area. These cylinders were made prior to 1990 by various manufacturers. As far as SCUBA goes I believe the majority of them were made by Luxfer which stopped using 6351 in June 1988. CGA says that these cracks take many years to develop, and "the 3-year periodic qualification period for composite and 5 year qualification period for all metal 6351 aluminum alloy cylinders provides ample opportunity to discover neck cracks before they lead to leaks." (Compressed Gas Association Pamphlet C 6.1, pg. 16, 2002) It then notes that the SCUBA industry has chosen to inspect all cylinders yearly regardless of material, manufacturer, or production date. Then it says that these inspection intervals are not required.
DIVE INDUSTRY'S PARANOID INTERPRETATION OF REAL SITUATION: Oh my god, we're all going to die if we fill a cylinder older than 15 years old! I don't care about you or your cylinder, or the fact that my job is to put air in cylinders in the first place. Nor do I care that we visually inspect cylinders FIVE TIMES AS OFTEN AS WE NEED TO. I'm going with my emotions and refuse everything because I want to come home to my wife and kids, even if there is absolutely no evidence to support my viewpoint or fears. I had to argue with one guy to get him to fill a Catalina cylinder (which never even used 6351 at any time), that was hydroed and visualed a month prior to this! And it wasn't even 15 years old. It just "looked like it was 15 years old."
Well, let's see if we can clear up a little of this confusion.................
When sustained load cracking was first detected as a problem with aluminum scuba cylinders, the entire industry, including the cylinder manufacturers were quite shocked. First, the problem came to light as a result of several rather serious cylinder explosions. This was a shock because aluminum cylinders (and all pressure vessels that carry hazardous gasses) are never supposed to explode. The designed failure criteria for pressure vessels is a "Leak Before Burst" failure mode. Nobody expected them to explode. Eventually, it was determined that the cause was "potentially" due to the development of cracks in the thread area of the cylinders. While they didn't know the exact cause of the problem, the quickly determined that there was a test method that could detect the beginning of these crack.......enter the Visual Eddy and Visual Plus inspection machines. These machines were quite expensive for the dive stores......approximately $1200 to $1800. The first instruction was to inspect "all" aluminum cylinders. Remember, not even Luxfer at the time knew the root cause of the problem.
As time moved on, Luxfer engineers determined that the problem only exhibited itself (as far as they could determine at the time) on 6361 cylinders. However, even Luxfer continued to suggest that all cylinders be so inspected during the visual inspection. Later, it was determined that ONLY the 6361 cylinders should be inspected. Even after making this determination, they did issue a credit recall for the 6361 cylinders, giving you, as an owner, an opportunity to return your 15 year old cylinder for a voucher worth approximately 1/3 the value of a brand new cylinder. This was not a lost leader on Luxfers part "just to get you to buy a new cylinder". It cost them real money to offer these vouchers. Some people choose not to return their cylinders. I don't know why. Simply simply made a choice. Later, after the return period had expired, many of those cylinders were put on the used market and were sold to unwary buyers......buyers that didn't know the cylinders had been recalled by the manufacturer and many buyers that simply relished the idea of getting a cylinder for pennies. Many stores did not have the resources to purchase the eddy current machines. Some of those stores chose to simply quit inspecting 6361 cylinders and many began the practice of refusing to fill them. The issues with "false positives" and "false negatives" was always an issue with the eddy current testing. Given the magnitude of the damage done when those cylinders did fail, many stores got even more nervous about filling them, even after they were eddy current inspected.
Another issue that was in the mind of "some" scuba stores was one we face in many types of industries.......were the manufacturers telling the retailers "all of the truth". It is unfortunate, but telling the whole truth is not something that can be universally expected from manufacturers that have a considerable product and litigation financial exposure. Remember, this problem was serious enough for Luxfer to put some money on the line to "buy them back". Then they come out and say "hey, with proper inspection, they are perfectly safe". So dive stores, not knowing what to believe, got even more strident in their desire to protect themselves. More and more simply refused to fill older cylinders......giving them a guarantee against a potential failure that could kill or mame themselves or their employees. After all, they viewed a 15 year old cylinder as well past its expected lifespan anyway, they knew all owners had the opportunity to exchange them for the vouchers, and the new replacements were quite inexpensive ($139-$179). Refusing to deal with those cylinders made perfect sense to many stores.
I agree that there is much ignorance among scuba store owners as to how older 6361 cylinders should be handled. There is no excuse for that ignorance, but it does exist. More enlightened scuba store operators stay well-read on the latest technical data from manufacturers.....some don't. They choose to put in place rules that THEY think will protect them. For this you cannot blame them. What you can do is evaluate stores on an individual basis and make your decision as to their prospects for getting any of your money.
On the Issue of CGA Standards: I respect the CGA standard completely, but like everything else from the government, they don't always do the best thing for every type of application. While we like to think of our industry as a vital and important one....the CGA standards you quote apply to about 5000 general commercial cylinders of every type for every 1 scuba cylinder tested. The CGA standard says not one word about the cleanliness of cylinders when they leave the hydrostatic test facility. The water they use to fill the cylinders for the test is often contaminated and leaves the cylinders pretty messy inside (at least from a breathing air perspective) You are welcome to take your cylinders down to the local fire service facility for hydro inspection and visual inspection. After all, that is the same place I take mine. I pay the hydro facility $12 each for the inspection, I drive them back and forth, and I clean the cylinders when I get them back. For this, I charge $25. I get $10 for the visual inspection, and we do a through job.
CrazyFingers, I don't know anything about you. Some of your posts seems to exhibit a little lack of knowledge about the subject to which you speak. That is ok. This is a good place to learn. If you are willing to listen. If you have a local store that is taking advantge of you, I am sorry. Don't think it is the entire industry. Many try their best to do the right thing, they try to charge a fair, competitive price. That some miss the mark on both of these attempts, I am certain. Thanks.
Phil Ellis
Good point. Though that won't get anything inside the tank, it will get salt water into the regulator and trash its innards.awap:
Rick
Just so you know the tanks passed the hydro test but failed the visual.Dive-aholic:
Pretty scary huh and it should be a huge eye opener for those who think visuals are a scam.
Scared Silly
Contributor
PhilEllis:
Good history Phil and is what I know as well. One nit pick here. The AL-6351 alloy cylinders have never been subject to a recall. Luxer offered a "trade-in" for the AL-6351 alloy cylinders. A recall would imply a defect where as the trade-in was good for business. BTW to date I know of approximately 20 SLC failures, there have been far more failures due to other factors.
Al Mialkovsky:
I'm sure it did. Had they kept the pressure up a little longer, it probably wouldn't have...
I'm a believer in visuals. I do my own. I also do my own fills most of the time. About the only time I get fills from a shop is when I'm away from home.
in_cavediver
Contributor
Al Mialkovsky:
Remeber though, Part of the CGA 6.x standards are a hydro AND VISUAL every 5 years. In the case mentioned, right after a hydro, by standards, it was to be visualed as well.
That said, I am trained to VIP tanks and I do my own about every year. Why, because it doesn't hurt to check and I like to keep some in O2 friendly status. I have yet to find a dive shop who wouldn't honor my stickers (which say I did the inspection, by name).
I do think quite a lot of the annual services are a scam. Its hard not to call it that when most manufacturers and shops try to keep the information from you 'for your own good' *and* require you to do routine service for warranties. Be glad, at least with tanks, the training, materials and information are very available to divers. And you might as well forget the life support arguement, its been dismissed over and over.
captain
Contributor
Rick Murchison:
You made my point, either the shop rat needs another job or the tank owner/diver needs to help the shop rat do his job or do it for him. Vis the rental tanks all you want. I make damm sure no water gets in my personal tanks. I vis them myself and never found water and I have owned most of them 35+ years.
Is it true that aluminum tanks always pass hydro...even with cracks? I have heard this before from some scuba techs.
Similar threads
