72 cf aluminum

[DA Aquamaster]

That would be one of the really bouyant 2475 psi service pressure AL 72's that Captain and WD8CDH mentioned, not one of the 3000 psi AL 72's.

The symbol in between month and year of the initial hydro is the symbol used by Alcan Aluminum. It is interesting that there is an Authorized Testing stamp in addition to the Alcan stamp.

SP 6498 was one of the early aluminum tank permits that was eventually rolled into the 3AL standard (which is when the 3AL was added). Specifically it was a permit issued to Luxfer and Alcan using Alcan's 6351-T6 alloy.

 

[Gilldiver]

That would be one of the really bouyant 2475 psi service pressure AL 72's that Captain and WD8CDH mentioned, not one of the 3000 psi AL 72's.

The symbol in between month and year of the initial hydro is the symbol used by Alcan Aluminum. It is interesting that there is an Authorized Testing stamp in addition to the Alcan stamp.

SP 6498 was one of the early aluminum tank permits that was eventually rolled into the 3AL standard (which is when the 3AL was added). Specifically it was a permit issued to Luxfer and Alcan using Alcan's 6351-T6 alloy.

I thought it might be an Alcan mark but was not sure.

 

[Dalfo002]

I picked up the same tank as Gilldiver's not too long ago, mine was manufactured 2/72 and still has the aqualung decals affixed to it. Of the shops that actually do hydros in-house only one nearby place would take it, but upon getting it back it had a tag reading "PASS - not to be used for scuba", i'm sure that's just a legal "i told ya so" but not many places will fill this thing even with the current stamp.

I'm not really sure what to do with it, so far the choices are,
A: leave it in the closet
B: dive with it (ignoring all the flack i catch about it already)
C: use it to power an air brush
D: use it as a buffer tank for a compressor, some kind of surface supply maybe...
E: see if i can fit a CO2 valve to it and have it re-stamped for CO2 service, then maybe i can serve everyone's favorite frosty beverages from my trunk after a dive trip...

and to get back to the topic, it is most definitely an Alcan mark, the name is written into the very bottom of the mark in small lettering, it doesn't look very legible in that photo, but it's there.

 

[DA Aquamaster]

"PASS - not to be used for scuba", i'm sure that's just a legal "i told ya so" .

That makes no sense. It will get filled to the same pressure if used for paintball and woudl probably see as many fill cycles.

How it is used just would not make a difference in term of SLC. In fact, I'd argue the opposite as if used in scuba service it woudl be subject to annaul VIP/ Visual Pluss/ Eddy current inspectiosn rather than just the DOT mandated VE inspection at hydro.

 

[ctcdg]

That makes no sense. It will get filled to the same pressure if used for paintball and woudl probably see as many fill cycles.

How it is used just would not make a difference in term of SLC. In fact, I'd argue the opposite as if used in scuba service it woudl be subject to annaul VIP/ Visual Pluss/ Eddy current inspectiosn rather than just the DOT mandated VE inspection at hydro.

OK guys, here we go again!!

49 CFR 180.209(m) specifies that a cylinder made from 6351 alloy must be eddy current examined AS PART OF the requalification if it is in SCUBA, SCBA, or oxygen service. This retest shop apparently didn't have the equipment to perform the eddy current examination, so the are waffling on it by adding their "not to be used for scuba". This is basically a violation of federal reg's since it is obviously a scuba cylinder.

And, NO the annual eddy current examination that is done by scuba shops does not qualify for the requalification. As part of the 5 year requal, the eddy current inspection must be performed by a RIN holder.

AND... you are exactly correct. It is ridiculous that DOT has required eddy current only for SCUBA, SCBA, and oxygen service, and exluded other applications and gases. "It's OK if the cylinder blows up and kills the nitrogen fill operator, but not the oxygen fill operator." How dumb is that???

BTW, it isn't surprising that Authorized Tesing has their stamp on the original test. Every cylinder is tested by a third party inspector (Independent Inspection Agence, IIA) at time of manufacture. Authorized is Luxfer's IIA. That is not Alcan's mark, but Authorized Testing's "AT" stamp (an "A" with the "T" formed in the cross bar of the "A"). Sometimes these get mixed up, but the IIA's mark is supposed to go in between the month and year of the original test. The mfg stamp should be over by the serial number. (Sometimes the mfg stamp is an "M" number.)

Take care, keep safe,

Darrell

 

[DA Aquamaster]

No it makes perfect sense now....It is just like getting a vehicle inspection but with anote on the windshield that says "passed but not to be used for driving."

-----

With regard to the Alcan stamp - that was exactly why I said it was strange to have the Alcan stamp there and then the authorized testing stamp elsewhere. In this case I also doubt Alcan actually made the tank (just the alloy) and in the position where it is at, you'd normally assume they are the third party tester, but then you have the authorized testing stamp off to the side. It suggests both tested the tank.

 

[John_B]

The Hy-Mark 72s are neutral in fresh water with a first and second stage attached at about 500 psi. So they are in effect about 3 lbs less buoyant than an AL 80.

They are also about 3 lbs lighter compared to an AL 80. When you compare numbers it offers many of the advantages of a steel 72 with a bit less negative buoyancy, about a pound less weight but a bit more height.

In terms of the numbers the differences do not sound like much but I absolutely hate using a steel 72 as a stage while the AL72 feels perfect.

Would the Hy-Mark 72s work well for doubles, using the same 6.9" tank bands as those used on the skinny Faber LP85s?

 

[Gilldiver]

BTW, it isn't surprising that Authorized Tesing has their stamp on the original test. Every cylinder is tested by a third party inspector (Independent Inspection Agence, IIA) at time of manufacture. Authorized is Luxfer's IIA. That is not Alcan's mark, but Authorized Testing's "AT" stamp (an "A" with the "T" formed in the cross bar of the "A"). Sometimes these get mixed up, but the IIA's mark is supposed to go in between the month and year of the original test. The mfg stamp should be over by the serial number. (Sometimes the mfg stamp is an "M" number.)

Darrell

If you look at the photo again the is the I in the A symbol of Industrial Analysis under the 0 of the serial number. The mark between the month and year is not a mark I am familiar with.

 

[ctcdg]

If you look at the photo again the is the I in the A symbol of Industrial Analysis under the 0 of the serial number. The mark between the month and year is not a mark I am familiar with.

Aha! I never saw the photo, I was just pointed to page 3 for comment. (I guess I should have gone back to previous pages!!)

You're right. I don't know what that is between the month and year, either.

Darrell

 

[DA Aquamaster]

If you read the thread you'd find we already established that as the Alcan Aluminum symbol and you'd now know what it was.