Old steels denied fills due to store "policy"

[txgoose]

What am I? Your research B1tch?

You were the one claiming that there may or may not have been flaws in the science review of this thread. Give examples or convince us where the lack of science review took place. I don’t care what names you call yourself.

 

[abnfrog]

most of these so called experts that say " no fill" this or that , more than likely don't have the knowledge or training/experience to really understand why they are saying that ...it might just be a way to sell tanks ..who knows ......but in the long run they just piss off the customer, if a lds resorts to bad practices it will in the end be their downfall......I recently had a call from a dive shop for a condemned cylinder (they know I need them to teach the vip class so I went down to pick it up , know what I got a 3 year old (yes almost new ) tank that they said failed eddy , I eddied it out myself pass , had 3 (yes 3) eddy techs after me all of us passed the tank ......no surprise there with a non 6351 tank

 

[Diving Dubai]

It could be as simple as the manufacturing specs, material used, and conditions of use combine to give a shorter life. The 2.5 year interval visual itself could give more than enough time to ruin a tank. Also, it has been overlooked in this discussion that a lot of old steel 72s have gone to scuba gear heaven over the decades, and we are left with the ones that have been treated well.


Bob

In the revised specification they tightened up the allowable limits. It has always been 2.5 year vis in the UK, there was a movement to reduce it to annual vis like the US, so teh tightening of allowable limits probably was a compromise that made all parties happy.

 

[Manatee Diver]

The interview said there must be a press release somwhere
Aluminium tanks - what every diver should know


Sustained load cracking is a defect that appears in some cylinders made from 6351 alloy. In the USA, this alloy was used by Luxfer Gas Cylinders from 1971 through to 1987. All Walter Kidde scuba cylinders were also made from 6351.

My understanding is that Luxfer didn't change all at once, some tanks were produced with the 6351 alloy later than others.

Personally I am not a big fan of the blanket "No tanks older than 1990" which has slowly morphed into "No tanks older than 20 years old," since a couple of my Catalina AL80s and Asahi HP100s would likely be approaching that age soon. My current shop doesn't care, and will even fill 6351 that have passed the required tests, but when I travel I don't always know the fill policy until I get there.

 

[Diving Dubai]

You were the one claiming that there may or may not have been flaws in the science review of this thread. Give examples or convince us where the lack of science review took place. I don’t care what names you call yourself.

I'll give you one last chance to stop being a jerk.

I haven't denied science. I have questioned the unwavering acceptance that passing hydro alone means that tank is going to be good until the next hydro.

In one article it was noted that pretty much all the tanks that failed hydro should have failed vis. In the case of aluminum tanks with cracking that should fail vis they could pass hydro. So it is perfectly possible for a tank with non acceptable defects to get through inspections.

While Hydro inspectors have to re-cert every 3 years vis inspectors do not. Its clear to most people that not all vis inspectors are as diligent as they might be. So it's perfectly possible that a cylinder can pass that shouldn't and could carry that defect through further vis inspections, until it fails vis with a different inspector, fails Hydro or goes bang.

I've also ascertained that there must be a finite life to cylinders. Whether actual or agreed. And I further stated that the cost of tanks meant there's no need to be using a 50 year old tank as they're pretty cheap. I've got 30 steels none are older than 2000 If I were still diving in another 20 years time I'd have replaced all of them before that. If for nothing more than piece of mind

 

[txgoose]

I'll give you one last chance to stop being a jerk.

Please report to the mods any of my posts where you feel that I have been insulting or rude. I don't care for it from others and I would like to be called out for it if I crossed a line.

I haven't denied science. I have questioned the unwavering acceptance that passing hydro alone means that tank is going to be good until the next hydro.

In one article it was noted that pretty much all the tanks that failed hydro should have failed vis. In the case of aluminum tanks with cracking that should fail vis they could pass hydro. So it is perfectly possible for a tank with non acceptable defects to get through inspections.

While Hydro inspectors have to re-cert every 3 years vis inspectors do not. Its clear to most people that not all vis inspectors are as diligent as they might be. So it's perfectly possible that a cylinder can pass that shouldn't and could carry that defect through further vis inspections, until it fails vis with a different inspector, fails Hydro or goes bang.

I've also ascertained that there must be a finite life to cylinders. Whether actual or agreed. And I further stated that the cost of tanks meant there's no need to be using a 50 year old tank as they're pretty cheap. I've got 30 steels none are older than 2000 If I were still diving in another 20 years time I'd have replaced all of them before that. If for nothing more than piece of mind

I and others have suggested that we (worldwide) have been storing compressed gasses in steel tanks for a century now, give or take a few years. The procedures and safety records have been fairly well studied and established. Navies, rescue teams, firefighters, and other first responder/safety oriented organizations seem to be good with the current standard. I am simply asking for evidence that these organizations, these safety related organizations, are not thinking out their gas storage policies well.

 

[Bob DBF]

Personally I am not a big fan of the blanket "No tanks older than 1990" which has slowly morphed into "No tanks older than 20 years old,"

It morphed into that in 2010 and between turnover in the industry, waiting for a problem to surface in other Al tanks, and seeing an increase in sales of new Al tanks, it was a win for the shops that didn't, or wouldn't, understand the issue. Knowing me and my tanks, the local shop gave me an extra year to get new tanks. Bought them there.

My current shop doesn't care, and will even fill 6351 that have passed the required tests, but when I travel I don't always know the fill policy until I get there.

That is the crux of the discussion, the choice between trusting science or ones "gut". Of course a business that also sells tanks may have a financial motive to embrace one side over the other.

I got out of the "bad alloy" issue years ago, as it was too much hassle and cost for me to continue using them. Using the same rules for Al tanks made now, or steel tanks, is just a sales tactic IMHO.



Bob

 

[Jiminy]

My understanding is that Luxfer didn't change all at once, some tanks were produced with the 6351 alloy later than others.

Personally I am not a big fan of the blanket "No tanks older than 1990" which has slowly morphed into "No tanks older than 20 years old," since a couple of my Catalina AL80s and Asahi HP100s would likely be approaching that age soon. My current shop doesn't care, and will even fill 6351 that have passed the required tests, but when I travel I don't always know the fill policy until I get there.

Seems you are correct this copy of the 1994 advisory shows 88 and 89 for some smaller cylinders

Notice No. 94-7; Safety Advisory; High Pressure Aluminum Seamless and Aluminum Composite Hoop-Wrapped Cylinders

 

[Diving Dubai]

Navies, rescue teams, firefighters, and other first responder/safety oriented organizations seem to be good with the current standard

I think you'll find (but I've no supporting evidence of their policies) that these entities would retire their cylinders after a relatively short time (15yrs?) mainly because of the frequent use they get and wear and tear.

 

[kelemvor]

Navies, rescue teams, firefighters, and other first responder/safety oriented organizations seem to be good with the current standard.

They are also not paying for their own gear, taxpayers are. In the end, that's what this is. A business that sells tanks and offers tank fills as a loss leader is creating a finite lifespan on old tanks. The policy may or may not have safety value for the fill station, but it definitely has value at the sales counter.