Nemrod 05134 tank question

[fringefan]

I just picked up a Nemrod tank and just wanted a little info. I know I have to have it inspected but it was used last year. It has an older style valve on it so I need to know if that can still be used?

I also bought an aluminum tank that was hydro in 02 stored with air and has the numbers Marked CTC DOT E6498-3000 885. The tank looks almost new .

These are my first tanks that I have owned and just wanted to get some expert opinions on them.

thanks
Fringe

 

[pescador775]

Are you in the US? I recall some steel Nemrod tanks. One of these was really large for the day. What are the details including markings? The number you gave sounds like a Euro designator but I forget what it means.

The aluminum tank is a US manufacture type made of 6351 T6 alloy. Some shops may refuse to fill and/ or require testing and expensive inspections.

 

[fringefan]

Yes I am in the US and the tank has a PADI internetional inspection program sticker on it. Here are all the number on the tank
THE NUMBERS ARE AS FOLLOWS:CC-3AA2250
64143CZ
05134
MN0271131710
That is all I can find
Fringe

 

[bugsmashers]

Hi,

The ICC was DOT's predecessor, and the 3AA means that it is steel. 2250 is the maximum filling pressure in psi, unless there is a + after the hydro stamp, then it can go 10% higher, legally.

I have 6 steel 72's with these markings, all date from the 60's. 3 of them still have the early valves. Just be sure to get a modern-style burst disk assembly installed in place of the spinner that is probably in it.

Ben

 

[fringefan]

Thanks I have called everyone I knew about these and no one new a thing but I new this would be the place. The old owner of our LDS would have known but he sold it a while back.

 

[Nemrod]

By older vavle what do you mean. Is it a pipe thread, 1/2 inch taper thread valve or is it a moder 3/4 straight thread? Is it a post valve, J or K calve?

I have owned Nemrod tanks with both straight and modrrn threads. Some of their steel tanks had molded in feet like a fire bottle. It is proably a good tank assuming it is not badly rusted internally.

The aluminum tank--toss it---dive shops will give you nothing but grief over older aluminum tanks made of that alloy. It is all pretty bogus but that is what it is. N

 

[Vicente]

Google for 6351 scuba tank, to find stories of 6351 tanks exploding. I do not believe this is bogus. Think of aluminum as being like particle-board used to make cheap furniture. Do you expect that cheap Ikea bookshelf to last through a bunch of moves without falling apart?

Aluminum is much more likely to result in lethal shrapnel when it does blow, than steel. Yes it might still be fine 30 years from now, pass inspection and everything. Or it might blow the head off some hapless fill-monkey next month. A risk I wouldn't take to squeeze a little more life out of an old tank.

 

[Nemrod]

"Google for 6351 scuba tank, to find stories of 6351 tanks exploding. I do not believe this is bogus. Think of aluminum as being like particle-board used to make cheap furniture. Do you expect that cheap Ikea bookshelf to last through a bunch of moves without falling apart?

Aluminum is much more likely to result in lethal shrapnel when it does blow, than steel. Yes it might still be fine 30 years from now, pass inspection and everything. Or it might blow the head off some hapless fill-monkey next month. A risk I wouldn't take to squeeze a little more life out of an old tank."

Oh baloney! N

 

[fire_diver]

Google for 6351 scuba tank, to find stories of 6351 tanks exploding. I do not believe this is bogus. Think of aluminum as being like particle-board used to make cheap furniture. Do you expect that cheap Ikea bookshelf to last through a bunch of moves without falling apart?

I cant believe you just compared a HP cylinder, made of 1/2 inch think AL, designed to be used through tens of thousands of fill cycles, to crappy import chi-com yuppie furniture.

Aluminum is much more likely to result in lethal shrapnel when it does blow, than steel. Yes it might still be fine 30 years from now, pass inspection and everything. Or it might blow the head off some hapless fill-monkey next month. A risk I wouldn't take to squeeze a little more life out of an old tank.

I think you've been listening to too many tank monkeys. If you had really done the research yourself, you have found that: No 6351 tank with current eddycurrent testing has ever failed. Of the tanks that have failed, it is 3 (three) out of 100,000's of 6351 tanks produced. Some reports show millions of 6351 tanks produced. The DOT did extensive investigation and found these tank are fine so long as they have an eddy-current test done at hydro EVERY 5 YEARS. They have no "shelf-life", and there is no reason not to use these tanks.

You know, we had this whole concept re-hashed many times. I offered to pay for the shipping to have every one of these "evil" tanks shipped to my house. Not one of the people who claimed to own them but never dive them again responded. I guess it's just "hip" to jump on a percieved band-wagon and bash something most people are too lazy or dumb to find the facts about.


FD

 

[rjack321]

It was more than 3, it seems about 8 stories float around the internet ether consistently. DOT cites 12 I believe - don't feel like checking the CFR today.

The "fact" that I've always struggled with is the "millions produced" line. Does this include LP CO2 cylinders? I have never gotten a satisfactory answer exactly how many HP scuba and scba 6351 cylinders were produced. You'd think they'd know (at least for Luxfers) based on serial #s.

Regardless...
Essentially 2 risk management decisions have been made.

1) DOT has said these cylinders are "safe enough" with 5 yr hydros, and 5 yr eddy current exams. Having requalifiers do eddy current exams is a bit misguided and it would have been better to make these annual eddy current exams with VIPs. But that's neither here nor there.

2) Dive shops (by and large) now refuse to fill these cylinders. They don't trust their competitors to do a proper visual/eddy current exam. (When in doubt, buy a new tank from us!)

The latter decision need not be based on facts or any particular statistics or science to be valid. Risk management is always a judgement call. It is just as legitimate to use trust/fear as a basis for decisionmaking as it is to use statistics.

Rare events can have a profound influence on the human psyche. As much as we might try to make rational decisions the fact is we make choices based on other factors every day. You might as well understand it and work with human nature rather than fighting against the tide using a totally different part of one's brain.