New DOT Hydro Requirements?

[DandyDon]

Sent my two to my LDS for viz and got a call back that one was out of Hydro - and the DOT had a new, additional test requirement - electrical viz exam maybe? I did not take notes so have only a vague recollection of what she said, but she did say that two of the first ten they did failed it.

Anyone know about this, please...?

 

[mike_s]

hard to say since you didn't mention what kind of tanks they are....

kinda like posting "my car is broke" without any of the other symptons or what kind of car it is.


are these old pre 1988 Aluminum tanks, made out of 6351T alloy?

there are a few new requirements such as a Eddy Test for the old cylinders for example. they are looking for "substained load cracking" issues on the 6351T tanks.



are they they old PST hydro exemption tanks? some of those have special hydro requirements

 

[Scared Silly]

Don, unless they are AL cylinders using the 6351 alloy there are no visual inspection tests other than the std. tests that all cylinders go through. If they are cylinders made from AL6351 then there is an eddy current test required.

Are any of your cylinders on this list?

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

 

[1_T_Submariner]

I googled it and didn't get anything new.

 

[spectrum]

Anyone know about this, please...?

Sounds like the Eddy current test required for the 6351 alloy cylinders. The requirement went into effect about 1 year ago, (maybe 2?). It is sometimes referred to as "Visual Inspection Plus.

It's an examination of the thread region for sustained load cracking. The eddy current test basically introduces a an electrical field and looks for a consistent eddy current response around the circumference of the neck. An examination with a tread scope is also performed.

Even with this all performed there is no assurance that a another shop be willing to fill a 6351 cylinder.

Pete

 

[DandyDon]

Really cannot answer the questions, sorry. The 80 cf Aluminum is one I got from my original Inst when he decided he couldn't make a living as an Inst in Plainview - no big surprise there. I don't know the details on it and it's at the LDS. I'll give them a ring Tuesday when they reopen and get more info.

thanks!

 

[halocline]

You should hope that they haven't heard all the hubub about filling old AL tanks out there in the prairie. Basically if it's a Luxfer (look on the tank, it'll say) and the original hydro date is prior to 1988, it's probably the older alloy. You wouldn't find a shop in the whole state of florida to fill one of those. (Exceptions, feel free to chime in!)

Where do you dive out there, anyway? Occasionally I'll drive up through west texas on my way to hiking in New Mexico. I don't see a lot of water....

 

[scubafanatic]

You should hope that they haven't heard all the hubub about filling old AL tanks out there in the prairie. Basically if it's a Luxfer (look on the tank, it'll say) and the original hydro date is prior to 1988, it's probably the older alloy. You wouldn't find a shop in the whole state of florida to fill one of those. (Exceptions, feel free to chime in!)

Where do you dive out there, anyway? Occasionally I'll drive up through west texas on my way to hiking in New Mexico. I don't see a lot of water....

.....I believe he dives the Blue Hole in New Mexico.....I did a tech class out there myself a few years ago.....it's one of the few dive spots out there.....it was an 8 hr dive, one way for me, driving at a pretty good clip too, from the Dallas/TX area...only went that one weekend for my class, otherwise WAY too far for practice/training...but I'm further away from it than Dandy Don is.

 

[NorthWoodsDiver]

Sent my two to my LDS for viz and got a call back that one was out of Hydro - and the DOT had a new, additional test requirement - electrical viz exam maybe? I did not take notes so have only a vague recollection of what she said, but she did say that two of the first ten they did failed it.

Anyone know about this, please...?

As others have pointed out the rule you speak of only pertains to ALUMINUM tanks and then only ALUMINUM tanks made by Walter Kiddie or some tanks from Luxfer.

any tank made after 1990 or so should be fine.

Walter Kiddie made only 6351 alloy tanks so all of their tanks require eddy current tests.

Luxfer changed to a better alloy around 1989 or so depending on the tank size but most any tank made after 1990 wont be a problem and certainly nothing made after 1991 will be a problem.

Eddy current testing is not necessary (or recommended) on steel tanks.

Also an eddy current test is NOT a substitute for a formal visual inspection and an eddy test may show a false positive reading so it should always be backed by a good visual.

The inspector should clean the threads and inspect the tank, he should be able to pick up anything the eddy is finding and the eddy machine will even tell him where to look.

If they fail your tanks based only on the eddy, take them some place else for a second opinion. DON'T let them deface the tanks!!!

if at all possible please supply us with ALL the numbers/letters/symbols from the tanks and we can help sort all this out.

T

 

[DandyDon]

You should hope that they haven't heard all the hubub about filling old AL tanks out there in the prairie. Basically if it's a Luxfer (look on the tank, it'll say) and the original hydro date is prior to 1988, it's probably the older alloy. You wouldn't find a shop in the whole state of florida to fill one of those. (Exceptions, feel free to chime in!)

Where do you dive out there, anyway? Occasionally I'll drive up through west texas on my way to hiking in New Mexico. I don't see a lot of water....

The tank purchase seemed like a good idea at the time, fairly new to diving and all, and it would have saved me rental fees with a Lubbock dive club sponsored by the LDS, but as it worked out - never use it really. Really need to unload it.

.....I believe he dives the Blue Hole in New Mexico.....I did a tech class out there myself a few years ago.....it's one of the few dive spots out there.....it was an 8 hr dive, one way for me, driving at a pretty good clip too, from the Dallas/TX area...only went that one weekend for my class, otherwise WAY too far for practice/training...but I'm further away from it than Dandy Don is.

Yep, and truthfully - I doubt that Stella would ever bother checking stickers, but then she supplies tank free with fills so I only take it once a year when it's due for viz and refill anyway.

As others have pointed out the rule you speak of only pertains to ALUMINUM tanks and then only ALUMINUM tanks made by Walter Kiddie or some tanks from Luxfer.

any tank made after 1990 or so should be fine.

Walter Kiddie made only 6351 alloy tanks so all of their tanks require eddy current tests.

Luxfer changed to a better alloy around 1989 or so depending on the tank size but most any tank made after 1990 wont be a problem and certainly nothing made after 1991 will be a problem.

Eddy current testing is not necessary (or recommended) on steel tanks.

Also an eddy current test is NOT a substitute for a formal visual inspection and an eddy test may show a false positive reading so it should always be backed by a good visual.

The inspector should clean the threads and inspect the tank, he should be able to pick up anything the eddy is finding and the eddy machine will even tell him where to look.

If they fail your tanks based only on the eddy, take them some place else for a second opinion. DON'T let them deface the tanks!!!

if at all possible please supply us with ALL the numbers/letters/symbols from the tanks and we can help sort all this out.

T

I do think that's what she was talking about, and she said they deface them when they fail. I need to get that tank and the numbers, see why they want to run the eddy, if that's what it is. Great help there; thanks!