How to identify a Luxfer 6351 tank?

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mksmith713

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Ok... so how do you identify the supposedly crappy 6351 AL tanks from the others......say....6051 tanks?

It might make a difference when shops won't fill a perfectly fine 6051 tank because the dates aren't what they like to see.
I know there were planty of 6051's made before 1989 and they're supposed to be fine.
It's the 6351 alloy that was supposed to be bad.

I just want to be an educated consumer when shopping for air.
 
check Luxfers website. they have a guide on there.

basically if it's made before May 1989 and is Luxfer, consider it a 6551T alloy. (someone correct me if I'm wrong)


regardless, most shops won't fill any aluminum tanks made before 1990 now because of it.
 
Here it is! Luxfer: Technical Bulletins: November 12, 2003

There is no reason to pick the May 1989 date when the S80 (by FAR the most common tank) was changed over before Jan '88. In fact, none of the SCUBA tanks were 6351 beyond June '88.

This matters because I have a Mar '88 S-80 tank. It is 6061...

Richard
 
Oddly, I have no problems getting my pre 1989 Catalinas filled by anyone.
But my pre 1989 Luxfers....well, I have to drive 45 minutes to a shop that will fill them.
 
Yet some shops will refuse fills just because it is pre '90 regardless of mfgr. If you are buying, avoid Al tanks manufactured before 1990. And don't be surprised when shops start declaring all Al tanks older than 20 years as unusable.
 
I read in another thread that the OP couldn't get pre 1990 Cats filled hence my statement.
 
The 6351 cylinders are not "crappy".... They just require an annual eddy current test in addition to the visual inspection.

A 6351 cylinder that passes annual inspection is just as "good" as a 6061 cylinder that passes inspection.

...regardless, most shops won't fill any aluminum tanks made before 1990 now because of it...

There's no reason not to fill a pre-1990 cylinder that has a valid eddy current , visual inspection sticker and hydro. Any fill operator who says differently is ignorant of the facts.
 
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https://www.shearwater.com/products/peregrine/

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